The segment descriptor contains information that is relevant to how linear
addresses need to be computed. It contains the default size of addresses
as well as the base address of the segment. Thus, given a segment
selector, we ought to look at segment descriptor to correctly calculate
the linear address.
In protected mode, the segment selector might indicate a segment
descriptor from either the global descriptor table or a local descriptor
table. Both cases are considered in this function.
This function is a prerequisite for functions in subsequent commits that
will obtain the aforementioned attributes of the segment descriptor.
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Garnier <thgarnie@google.com>
Link: https://lkml.kernel.org/r/1509135945-13762-15-git-send-email-ricardo.neri-calderon@linux.intel.com
When computing a linear address and segmentation is used, we need to know
the base address of the segment involved in the computation. In most of
the cases, the segment base address will be zero as in USER_DS/USER32_DS.
However, it may be possible that a user space program defines its own
segments via a local descriptor table. In such a case, the segment base
address may not be zero. Thus, the segment base address is needed to
calculate correctly the linear address.
If running in protected mode, the segment selector to be used when
computing a linear address is determined by either any of segment override
prefixes in the instruction or inferred from the registers involved in the
computation of the effective address; in that order. Also, there are cases
when the segment override prefixes shall be ignored (i.e., code segments
are always selected by the CS segment register; string instructions always
use the ES segment register when using rDI register as operand). In long
mode, segment registers are ignored, except for FS and GS. In these two
cases, base addresses are obtained from the respective MSRs.
For clarity, this process can be split into four steps (and an equal
number of functions): determine if segment prefixes overrides can be used;
parse the segment override prefixes, and use them if found; if not found
or cannot be used, use the default segment registers associated with the
operand registers. Once the segment register to use has been identified,
read its value to obtain the segment selector.
The method to obtain the segment selector depends on several factors. In
32-bit builds, segment selectors are saved into a pt_regs structure
when switching to kernel mode. The same is also true for virtual-8086
mode. In 64-bit builds, segmentation is mostly ignored, except when
running a program in 32-bit legacy mode. In this case, CS and SS can be
obtained from pt_regs. DS, ES, FS and GS can be read directly from
the respective segment registers.
In order to identify the segment registers, a new set of #defines is
introduced. It also includes two special identifiers. One of them
indicates when the default segment register associated with instruction
operands shall be used. Another one indicates that the contents of the
segment register shall be ignored; this identifier is used when in long
mode.
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Garnier <thgarnie@google.com>
Link: https://lkml.kernel.org/r/1509135945-13762-14-git-send-email-ricardo.neri-calderon@linux.intel.com
String instructions are special because, in protected mode, the linear
address is always obtained via the ES segment register in operands that
use the (E)DI register; the DS segment register in operands that use
the (E)SI register. Furthermore, segment override prefixes are ignored
when calculating a linear address involving the (E)DI register; segment
override prefixes can be used when calculating linear addresses involving
the (E)SI register.
It follows that linear addresses are calculated differently for the case of
string instructions. The purpose of this utility function is to identify
such instructions for callers to determine a linear address correctly.
Note that this function only identifies string instructions; it does not
determine what segment register to use in the address computation. That is
left to callers. A subsequent commmit introduces a function to determine
the segment register to use given the instruction, operands and
segment override prefixes.
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Garnier <thgarnie@google.com>
Link: https://lkml.kernel.org/r/1509135945-13762-13-git-send-email-ricardo.neri-calderon@linux.intel.com
The function get_reg_offset() returns the offset to the register the
argument specifies as indicated in an enumeration of type offset. Callers
of this function would need the definition of such enumeration. This is
not needed. Instead, add helper functions for this purpose. These functions
are useful in cases when, for instance, the caller needs to decide whether
the operand is a register or a memory location by looking at the rm part
of the ModRM byte. As of now, this is the only helper function that is
needed.
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Garnier <thgarnie@google.com>
Link: https://lkml.kernel.org/r/1509135945-13762-12-git-send-email-ricardo.neri-calderon@linux.intel.com
We are not in a critical failure path. The invalid register type is caused
when trying to decode invalid instruction bytes from a user-space program.
Thus, simply print an error message. To prevent this warning from being
abused from user space programs, use the rate-limited variant of pr_err().
along with a descriptive prefix.
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Garnier <thgarnie@google.com>
Link: https://lkml.kernel.org/r/1509135945-13762-11-git-send-email-ricardo.neri-calderon@linux.intel.com
Other kernel submodules can benefit from using the utility functions
defined in mpx.c to obtain the addresses and values of operands contained
in the general purpose registers. An instance of this is the emulation code
used for instructions protected by the Intel User-Mode Instruction
Prevention feature.
Thus, these functions are relocated to a new insn-eval.c file. The reason
to not relocate these utilities into insn.c is that the latter solely
analyses instructions given by a struct insn without any knowledge of the
meaning of the values of instruction operands. This new utility insn-
eval.c aims to be used to resolve userspace linear addresses based on
the contents of the instruction operands as well as the contents of pt_regs
structure.
These utilities come with a separate header. This is to avoid taking insn.c
out of sync from the instructions decoders under tools/obj and tools/perf.
This also avoids adding cumbersome #ifdef's for the #include'd files
required to decode instructions in a kernel context.
Functions are simply relocated. There are not functional or indentation
changes.
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Garnier <thgarnie@google.com>
Link: https://lkml.kernel.org/r/1509135945-13762-10-git-send-email-ricardo.neri-calderon@linux.intel.com
Add a cmdline_find_option() function to look for cmdline options that
take arguments. The argument is returned in a supplied buffer and the
argument length (regardless of whether it fits in the supplied buffer)
is returned, with -1 indicating not found.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/36b5f97492a9745dce27682305f990fc20e5cf8a.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This adds support for compiling with a rough equivalent to the glibc
_FORTIFY_SOURCE=1 feature, providing compile-time and runtime buffer
overflow checks for string.h functions when the compiler determines the
size of the source or destination buffer at compile-time. Unlike glibc,
it covers buffer reads in addition to writes.
GNU C __builtin_*_chk intrinsics are avoided because they would force a
much more complex implementation. They aren't designed to detect read
overflows and offer no real benefit when using an implementation based
on inline checks. Inline checks don't add up to much code size and
allow full use of the regular string intrinsics while avoiding the need
for a bunch of _chk functions and per-arch assembly to avoid wrapper
overhead.
This detects various overflows at compile-time in various drivers and
some non-x86 core kernel code. There will likely be issues caught in
regular use at runtime too.
Future improvements left out of initial implementation for simplicity,
as it's all quite optional and can be done incrementally:
* Some of the fortified string functions (strncpy, strcat), don't yet
place a limit on reads from the source based on __builtin_object_size of
the source buffer.
* Extending coverage to more string functions like strlcat.
* It should be possible to optionally use __builtin_object_size(x, 1) for
some functions (C strings) to detect intra-object overflows (like
glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative
approach to avoid likely compatibility issues.
* The compile-time checks should be made available via a separate config
option which can be enabled by default (or always enabled) once enough
time has passed to get the issues it catches fixed.
Kees said:
"This is great to have. While it was out-of-tree code, it would have
blocked at least CVE-2016-3858 from being exploitable (improper size
argument to strlcpy()). I've sent a number of fixes for
out-of-bounds-reads that this detected upstream already"
[arnd@arndb.de: x86: fix fortified memcpy]
Link: http://lkml.kernel.org/r/20170627150047.660360-1-arnd@arndb.de
[keescook@chromium.org: avoid panic() in favor of BUG()]
Link: http://lkml.kernel.org/r/20170626235122.GA25261@beast
[keescook@chromium.org: move from -mm, add ARCH_HAS_FORTIFY_SOURCE, tweak Kconfig help]
Link: http://lkml.kernel.org/r/20170526095404.20439-1-danielmicay@gmail.com
Link: http://lkml.kernel.org/r/1497903987-21002-8-git-send-email-keescook@chromium.org
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Introduce the _flushcache() family of memory copy helpers and use them
for persistent memory write operations on x86. The _flushcache()
semantic indicates that the cache is either bypassed for the copy
operation (movnt) or any lines dirtied by the copy operation are
written back (clwb, clflushopt, or clflush).
* Extend dax_operations with ->copy_from_iter() and ->flush()
operations. These operations and other infrastructure updates allow
all persistent memory specific dax functionality to be pushed into
libnvdimm and the pmem driver directly. It also allows dax-specific
sysfs attributes to be linked to a host device, for example:
/sys/block/pmem0/dax/write_cache
* Add support for the new NVDIMM platform/firmware mechanisms introduced
in ACPI 6.2 and UEFI 2.7. This support includes the v1.2 namespace
label format, extensions to the address-range-scrub command set, new
error injection commands, and a new BTT (block-translation-table)
layout. These updates support inter-OS and pre-OS compatibility.
* Fix a longstanding memory corruption bug in nfit_test.
* Make the pmem and nvdimm-region 'badblocks' sysfs files poll(2)
capable.
* Miscellaneous fixes and small updates across libnvdimm and the nfit
driver.
Acknowledgements that came after the branch was pushed:
commit 6aa734a2f3 "libnvdimm, region, pmem: fix 'badblocks'
sysfs_get_dirent() reference lifetime"
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
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Merge tag 'libnvdimm-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
"libnvdimm updates for the latest ACPI and UEFI specifications. This
pull request also includes new 'struct dax_operations' enabling to
undo the abuse of copy_user_nocache() for copy operations to pmem.
The dax work originally missed 4.12 to address concerns raised by Al.
Summary:
- Introduce the _flushcache() family of memory copy helpers and use
them for persistent memory write operations on x86. The
_flushcache() semantic indicates that the cache is either bypassed
for the copy operation (movnt) or any lines dirtied by the copy
operation are written back (clwb, clflushopt, or clflush).
- Extend dax_operations with ->copy_from_iter() and ->flush()
operations. These operations and other infrastructure updates allow
all persistent memory specific dax functionality to be pushed into
libnvdimm and the pmem driver directly. It also allows dax-specific
sysfs attributes to be linked to a host device, for example:
/sys/block/pmem0/dax/write_cache
- Add support for the new NVDIMM platform/firmware mechanisms
introduced in ACPI 6.2 and UEFI 2.7. This support includes the v1.2
namespace label format, extensions to the address-range-scrub
command set, new error injection commands, and a new BTT
(block-translation-table) layout. These updates support inter-OS
and pre-OS compatibility.
- Fix a longstanding memory corruption bug in nfit_test.
- Make the pmem and nvdimm-region 'badblocks' sysfs files poll(2)
capable.
- Miscellaneous fixes and small updates across libnvdimm and the nfit
driver.
Acknowledgements that came after the branch was pushed: commit
6aa734a2f3 ("libnvdimm, region, pmem: fix 'badblocks'
sysfs_get_dirent() reference lifetime") was reviewed by Toshi Kani
<toshi.kani@hpe.com>"
* tag 'libnvdimm-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (42 commits)
libnvdimm, namespace: record 'lbasize' for pmem namespaces
acpi/nfit: Issue Start ARS to retrieve existing records
libnvdimm: New ACPI 6.2 DSM functions
acpi, nfit: Show bus_dsm_mask in sysfs
libnvdimm, acpi, nfit: Add bus level dsm mask for pass thru.
acpi, nfit: Enable DSM pass thru for root functions.
libnvdimm: passthru functions clear to send
libnvdimm, btt: convert some info messages to warn/err
libnvdimm, region, pmem: fix 'badblocks' sysfs_get_dirent() reference lifetime
libnvdimm: fix the clear-error check in nsio_rw_bytes
libnvdimm, btt: fix btt_rw_page not returning errors
acpi, nfit: quiet invalid block-aperture-region warnings
libnvdimm, btt: BTT updates for UEFI 2.7 format
acpi, nfit: constify *_attribute_group
libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region
libnvdimm, pmem, dax: export a cache control attribute
dax: convert to bitmask for flags
dax: remove default copy_from_iter fallback
libnvdimm, nfit: enable support for volatile ranges
libnvdimm, pmem: fix persistence warning
...
Pull x86 asm updates from Ingo Molnar:
"A single commit micro-optimizing short user copies on certain Intel
CPUs"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/uaccess: Optimize copy_user_enhanced_fast_string() for short strings
Pull perf updates from Ingo Molnar:
"Most of the changes are for tooling, the main changes in this cycle were:
- Improve Intel-PT hardware tracing support, both on the kernel and
on the tooling side: PTWRITE instruction support, power events for
C-state tracing, etc. (Adrian Hunter)
- Add support to measure SMI cost to the x86 architecture, with
tooling support in 'perf stat' (Kan Liang)
- Support function filtering in 'perf ftrace', plus related
improvements (Namhyung Kim)
- Allow adding and removing fields to the default 'perf script'
columns, using + or - as field prefixes to do so (Andi Kleen)
- Allow resolving the DSO name with 'perf script -F brstack{sym,off},dso'
(Mark Santaniello)
- Add perf tooling unwind support for PowerPC (Paolo Bonzini)
- ... and various other improvements as well"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits)
perf auxtrace: Add CPU filter support
perf intel-pt: Do not use TSC packets for calculating CPU cycles to TSC
perf intel-pt: Update documentation to include new ptwrite and power events
perf intel-pt: Add example script for power events and PTWRITE
perf intel-pt: Synthesize new power and "ptwrite" events
perf intel-pt: Move code in intel_pt_synth_events() to simplify attr setting
perf intel-pt: Factor out intel_pt_set_event_name()
perf intel-pt: Tidy messages into called function intel_pt_synth_event()
perf intel-pt: Tidy Intel PT evsel lookup into separate function
perf intel-pt: Join needlessly wrapped lines
perf intel-pt: Remove unused instructions_sample_period
perf intel-pt: Factor out common code synthesizing event samples
perf script: Add synthesized Intel PT power and ptwrite events
perf/x86/intel: Constify the 'lbr_desc[]' array and make a function static
perf script: Add 'synth' field for synthesized event payloads
perf auxtrace: Add itrace option to output power events
perf auxtrace: Add itrace option to output ptwrite events
tools include: Add byte-swapping macros to kernel.h
perf script: Add 'synth' event type for synthesized events
x86/insn: perf tools: Add new ptwrite instruction
...
In preparation for an objtool rewrite which will have broader checks,
whitelist functions and files which cause problems because they do
unusual things with the stack.
These whitelists serve as a TODO list for which functions and files
don't yet have undwarf unwinder coverage. Eventually most of the
whitelists can be removed in favor of manual CFI hint annotations or
objtool improvements.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/7f934a5d707a574bda33ea282e9478e627fb1829.1498659915.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
According to the Intel datasheet, the REP MOVSB instruction
exposes a pretty heavy setup cost (50 ticks), which hurts
short string copy operations.
This change tries to avoid this cost by calling the explicit
loop available in the unrolled code for strings shorter
than 64 bytes.
The 64 bytes cutoff value is arbitrary from the code logic
point of view - it has been selected based on measurements,
as the largest value that still ensures a measurable gain.
Micro benchmarks of the __copy_from_user() function with
lengths in the [0-63] range show this performance gain
(shorter the string, larger the gain):
- in the [55%-4%] range on Intel Xeon(R) CPU E5-2690 v4
- in the [72%-9%] range on Intel Core i7-4810MQ
Other tested CPUs - namely Intel Atom S1260 and AMD Opteron
8216 - show no difference, because they do not expose the
ERMS feature bit.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4533a1d101fd460f80e21329a34928fad521c1d4.1498744345.git.pabeni@redhat.com
[ Clarified the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add ptwrite to the op code map and the perf tools new instructions test.
To run the test:
$ tools/perf/perf test "x86 ins"
39: Test x86 instruction decoder - new instructions : Ok
Or to see the details:
$ tools/perf/perf test -v "x86 ins" 2>&1 | grep ptwrite
For information about ptwrite, refer the Intel SDM.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/1495180230-19367-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
With all handling of the CONFIG_ARCH_HAS_PMEM_API case being moved to
libnvdimm and the pmem driver directly we do not need to provide global
wrappers and fallbacks in the CONFIG_ARCH_HAS_PMEM_API=n case. The pmem
driver will simply not link to arch_wb_cache_pmem() in that case. Same
as before, pmem flushing is only defined for x86_64, via
clean_cache_range(), but it is straightforward to add other archs in the
future.
arch_wb_cache_pmem() is an exported function since the pmem module needs
to find it, but it is privately declared in drivers/nvdimm/pmem.h because
there are no consumers outside of the pmem driver.
Cc: <x86@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The pmem driver has a need to transfer data with a persistent memory
destination and be able to rely on the fact that the destination writes are not
cached. It is sufficient for the writes to be flushed to a cpu-store-buffer
(non-temporal / "movnt" in x86 terms), as we expect userspace to call fsync()
to ensure data-writes have reached a power-fail-safe zone in the platform. The
fsync() triggers a REQ_FUA or REQ_FLUSH to the pmem driver which will turn
around and fence previous writes with an "sfence".
Implement a __copy_from_user_inatomic_flushcache, memcpy_page_flushcache, and
memcpy_flushcache, that guarantee that the destination buffer is not dirty in
the cpu cache on completion. The new copy_from_iter_flushcache and sub-routines
will be used to replace the "pmem api" (include/linux/pmem.h +
arch/x86/include/asm/pmem.h). The availability of copy_from_iter_flushcache()
and memcpy_flushcache() are gated by the CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
config symbol, and fallback to copy_from_iter_nocache() and plain memcpy()
otherwise.
This is meant to satisfy the concern from Linus that if a driver wants to do
something beyond the normal nocache semantics it should be something private to
that driver [1], and Al's concern that anything uaccess related belongs with
the rest of the uaccess code [2].
The first consumer of this interface is a new 'copy_from_iter' dax operation so
that pmem can inject cache maintenance operations without imposing this
overhead on other dax-capable drivers.
[1]: https://lists.01.org/pipermail/linux-nvdimm/2017-January/008364.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2017-April/009942.html
Cc: <x86@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The constraint "rm" allows the compiler to put mix_const into memory.
When the input operand is a memory location then MUL needs an operand
size suffix, since Clang can't infer the multiplication width from the
operand.
Add and use the _ASM_MUL macro which determines the operand size and
resolves to the NUL instruction with the corresponding suffix.
This fixes the following error when building with clang:
CC arch/x86/lib/kaslr.o
/tmp/kaslr-dfe1ad.s: Assembler messages:
/tmp/kaslr-dfe1ad.s:182: Error: no instruction mnemonic suffix given and no register operands; can't size instruction
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Grant Grundler <grundler@chromium.org>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Davidson <md@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170501224741.133938-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andrey Konovalov reported the following warning while fuzzing the kernel
with syzkaller:
WARNING: kernel stack regs at ffff8800686869f8 in a.out:4933 has bad 'bp' value c3fc855a10167ec0
The unwinder dump revealed that RBP had a bad value when an interrupt
occurred in csum_partial_copy_generic().
That function saves RBP on the stack and then overwrites it, using it as
a scratch register. That's problematic because it breaks stack traces
if an interrupt occurs in the middle of the function.
Replace the usage of RBP with another callee-saved register (R15) so
stack traces are no longer affected.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: linux-sctp@vger.kernel.org
Cc: netdev <netdev@vger.kernel.org>
Cc: syzkaller <syzkaller@googlegroups.com>
Link: http://lkml.kernel.org/r/4b03a961efda5ec9bfe46b7b9c9ad72d1efad343.1493909486.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 asm updates from Ingo Molnar:
"The main changes in this cycle were:
- unwinder fixes and enhancements
- improve ftrace interaction with the unwinder
- optimize the code footprint of WARN() and related debugging
constructs
- ... plus misc updates, cleanups and fixes"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86/unwind: Dump all stacks in unwind_dump()
x86/unwind: Silence more entry-code related warnings
x86/ftrace: Fix ebp in ftrace_regs_caller that screws up unwinder
x86/unwind: Remove unused 'sp' parameter in unwind_dump()
x86/unwind: Prepend hex mask value with '0x' in unwind_dump()
x86/unwind: Properly zero-pad 32-bit values in unwind_dump()
x86/unwind: Ensure stack pointer is aligned
debug: Avoid setting BUGFLAG_WARNING twice
x86/unwind: Silence entry-related warnings
x86/unwind: Read stack return address in update_stack_state()
x86/unwind: Move common code into update_stack_state()
debug: Fix __bug_table[] in arch linker scripts
debug: Add _ONCE() logic to report_bug()
x86/debug: Define BUG() again for !CONFIG_BUG
x86/debug: Implement __WARN() using UD0
x86/ftrace: Use Makefile logic instead of #ifdef for compiling ftrace_*.o
x86/ftrace: Add -mfentry support to x86_32 with DYNAMIC_FTRACE set
x86/ftrace: Clean up ftrace_regs_caller
x86/ftrace: Add stack frame pointer to ftrace_caller
x86/ftrace: Move the ftrace specific code out of entry_32.S
...
Pull x86 boot updates from Ingo Molnar:
"The biggest changes in this cycle were:
- reworking of the e820 code: separate in-kernel and boot-ABI data
structures and apply a whole range of cleanups to the kernel side.
No change in functionality.
- enable KASLR by default: it's used by all major distros and it's
out of the experimental stage as well.
- ... misc fixes and cleanups"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
x86/KASLR: Fix kexec kernel boot crash when KASLR randomization fails
x86/reboot: Turn off KVM when halting a CPU
x86/boot: Fix BSS corruption/overwrite bug in early x86 kernel startup
x86: Enable KASLR by default
boot/param: Move next_arg() function to lib/cmdline.c for later reuse
x86/boot: Fix Sparse warning by including required header file
x86/boot/64: Rename start_cpu()
x86/xen: Update e820 table handling to the new core x86 E820 code
x86/boot: Fix pr_debug() API braindamage
xen, x86/headers: Add <linux/device.h> dependency to <asm/xen/page.h>
x86/boot/e820: Simplify e820__update_table()
x86/boot/e820: Separate the E820 ABI structures from the in-kernel structures
x86/boot/e820: Fix and clean up e820_type switch() statements
x86/boot/e820: Rename the remaining E820 APIs to the e820__*() prefix
x86/boot/e820: Remove unnecessary #include's
x86/boot/e820: Rename e820_mark_nosave_regions() to e820__register_nosave_regions()
x86/boot/e820: Rename e820_reserve_resources*() to e820__reserve_resources*()
x86/boot/e820: Use bool in query APIs
x86/boot/e820: Document e820__reserve_setup_data()
x86/boot/e820: Clean up __e820__update_table() et al
...
Pull uaccess unification updates from Al Viro:
"This is the uaccess unification pile. It's _not_ the end of uaccess
work, but the next batch of that will go into the next cycle. This one
mostly takes copy_from_user() and friends out of arch/* and gets the
zero-padding behaviour in sync for all architectures.
Dealing with the nocache/writethrough mess is for the next cycle;
fortunately, that's x86-only. Same for cleanups in iov_iter.c (I am
sold on access_ok() in there, BTW; just not in this pile), same for
reducing __copy_... callsites, strn*... stuff, etc. - there will be a
pile about as large as this one in the next merge window.
This one sat in -next for weeks. -3KLoC"
* 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (96 commits)
HAVE_ARCH_HARDENED_USERCOPY is unconditional now
CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now
m32r: switch to RAW_COPY_USER
hexagon: switch to RAW_COPY_USER
microblaze: switch to RAW_COPY_USER
get rid of padding, switch to RAW_COPY_USER
ia64: get rid of copy_in_user()
ia64: sanitize __access_ok()
ia64: get rid of 'segment' argument of __do_{get,put}_user()
ia64: get rid of 'segment' argument of __{get,put}_user_check()
ia64: add extable.h
powerpc: get rid of zeroing, switch to RAW_COPY_USER
esas2r: don't open-code memdup_user()
alpha: fix stack smashing in old_adjtimex(2)
don't open-code kernel_setsockopt()
mips: switch to RAW_COPY_USER
mips: get rid of tail-zeroing in primitives
mips: make copy_from_user() zero tail explicitly
mips: clean and reorder the forest of macros...
mips: consolidate __invoke_... wrappers
...
Newer hardware has uncovered a bug in the software implementation of
using MWAITX for the delay function. A value of 0 for the timer is meant
to indicate that a timeout will not be used to exit MWAITX. On newer
hardware this can result in MWAITX never returning, resulting in NMI
soft lockup messages being printed. On older hardware, some of the other
conditions under which MWAITX can exit masked this issue. The AMD APM
does not currently document this and will be updated.
Please refer to http://marc.info/?l=kvm&m=148950623231140 for
information regarding NMI soft lockup messages on an AMD Ryzen 1800X.
This has been root-caused as a 0 passed to MWAITX causing it to wait
indefinitely.
This change has the added benefit of avoiding the unnecessary setup of
MONITORX/MWAITX when the delay value is zero.
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Link: http://lkml.kernel.org/r/1493156643-29366-1-git-send-email-Janakarajan.Natarajan@amd.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Back in commit:
92b0729c34 ("x86/mm, x86/mce: Add memcpy_mcsafe()")
... I made a copy/paste error setting up the exception table entries
and ended up with two for label .L_cache_w3 and none for .L_cache_w2.
This means that if we take a machine check on:
.L_cache_w2: movq 2*8(%rsi), %r10
then we don't have an exception table entry for this instruction
and we can't recover.
Fix: s/3/2/
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 92b0729c34 ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Link: http://lkml.kernel.org/r/1490046030-25862-1-git-send-email-tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In line with asm/e820/types.h, move the e820 API declarations to
asm/e820/api.h and update all usage sites.
This is just a mechanical, obviously correct move & replace patch,
there will be subsequent changes to clean up the code and to make
better use of the new header organization.
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When a panic happens during bootup, "Rebooting in X seconds.." is
shown, but reboot happens immediatelly. It is because panic() uses mdelay()
and mdelay() calls __const_udelay() immediately, which does not
work while booting.
The per_cpu cpu_info.loops_per_jiffy value is not initialized yet, so
__const_udelay() actually multiplies the number of loops by zero. This
results in __const_udelay() to delay the execution only by a nanosecond
or so.
So check whether cpu_info.loops_per_jiffy is zero and use
loops_per_jiffy in that case. mdelay() will not be so precise without
proper calibration, but it works relatively well.
Before:
[ 0.170039] delaying 100ms
[ 0.170828] done
After
[ 0.214042] delaying 100ms
[ 0.313974] done
I do not think the added check matters given we are about to spin the
processor in the next few hundred cycles.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170119114730.2670-1-jslaby@suse.cz
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 asm updates from Ingo Molnar:
"The main changes in this development cycle were:
- a large number of call stack dumping/printing improvements: higher
robustness, better cross-context dumping, improved output, etc.
(Josh Poimboeuf)
- vDSO getcpu() performance improvement for future Intel CPUs with
the RDPID instruction (Andy Lutomirski)
- add two new Intel AVX512 features and the CPUID support
infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela,
He Chen)
- more copy-user unification (Borislav Petkov)
- entry code assembly macro simplifications (Alexander Kuleshov)
- vDSO C/R support improvements (Dmitry Safonov)
- misc fixes and cleanups (Borislav Petkov, Paul Bolle)"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
scripts/decode_stacktrace.sh: Fix address line detection on x86
x86/boot/64: Use defines for page size
x86/dumpstack: Make stack name tags more comprehensible
selftests/x86: Add test_vdso to test getcpu()
x86/vdso: Use RDPID in preference to LSL when available
x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl()
x86/cpufeatures: Enable new AVX512 cpu features
x86/cpuid: Provide get_scattered_cpuid_leaf()
x86/cpuid: Cleanup cpuid_regs definitions
x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
x86/unwind: Ensure stack grows down
x86/vdso: Set vDSO pointer only after success
x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE
x86/unwind: Detect bad stack return address
x86/dumpstack: Warn on stack recursion
x86/unwind: Warn on bad frame pointer
x86/decoder: Use stderr if insn sanity test fails
x86/decoder: Use stdout if insn decoder test is successful
mm/page_alloc: Remove kernel address exposure in free_reserved_area()
x86/dumpstack: Remove raw stack dump
...
Make the MSR argument an unsigned int, both low and high u32, put
"notrace" last in the function signature. Reflow function signatures for
better readability and cleanup white space.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We already have the same functionality in usercopy_32.c. Share it with
64-bit and get rid of some more asm glue which is not needed anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161031151015.22087-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull kbuild updates from Michal Marek:
- EXPORT_SYMBOL for asm source by Al Viro.
This does bring a regression, because genksyms no longer generates
checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
working on a patch to fix this.
Plus, we are talking about functions like strcpy(), which rarely
change prototypes.
- Fixes for PPC fallout of the above by Stephen Rothwell and Nick
Piggin
- fixdep speedup by Alexey Dobriyan.
- preparatory work by Nick Piggin to allow architectures to build with
-ffunction-sections, -fdata-sections and --gc-sections
- CONFIG_THIN_ARCHIVES support by Stephen Rothwell
- fix for filenames with colons in the initramfs source by me.
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
initramfs: Escape colons in depfile
ppc: there is no clear_pages to export
powerpc/64: whitelist unresolved modversions CRCs
kbuild: -ffunction-sections fix for archs with conflicting sections
kbuild: add arch specific post-link Makefile
kbuild: allow archs to select link dead code/data elimination
kbuild: allow architectures to use thin archives instead of ld -r
kbuild: Regenerate genksyms lexer
kbuild: genksyms fix for typeof handling
fixdep: faster CONFIG_ search
ia64: move exports to definitions
sparc32: debride memcpy.S a bit
[sparc] unify 32bit and 64bit string.h
sparc: move exports to definitions
ppc: move exports to definitions
arm: move exports to definitions
s390: move exports to definitions
m68k: move exports to definitions
alpha: move exports to actual definitions
x86: move exports to actual definitions
...
Use the mcsafe_key defined in the previous patch to make decisions on which
copy function to use. We can't use the FEATURE bit any more because PCI
quirks run too late to affect the patching of code. So we use a static key.
Turn memcpy_mcsafe() into an inline function to make life easier for
callers. The assembly code that actually does the copy is now named
memcpy_mcsafe_unrolled()
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/bfde2fc774e94f53d91b70a4321c85a0d33e7118.1472754712.git.tony.luck@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
debug_putstr() is used to output strings without using printf-like
formatting but debug_putstr(v) is defined as early_printk(v) in
arch/x86/lib/kaslr.c.
This makes clang reports the following warning when building
with -Wformat-security:
arch/x86/lib/kaslr.c:57:15: warning: format string is not a string
literal (potentially insecure) [-Wformat-security]
debug_putstr(purpose);
^~~~~~~
Fix this by using "%s" in early_printk().
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160806102039.27221-1-nicolas.iooss_linux@m4x.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 header cleanups from Ingo Molnar:
"This tree is a cleanup of the x86 tree reducing spurious uses of
module.h - which should improve build performance a bit"
* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads
x86/apic: Remove duplicated include from probe_64.c
x86/ce4100: Remove duplicated include from ce4100.c
x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t
x86/platform: Delete extraneous MODULE_* tags fromm ts5500
x86: Audit and remove any remaining unnecessary uses of module.h
x86/kvm: Audit and remove any unnecessary uses of module.h
x86/xen: Audit and remove any unnecessary uses of module.h
x86/platform: Audit and remove any unnecessary uses of module.h
x86/lib: Audit and remove any unnecessary uses of module.h
x86/kernel: Audit and remove any unnecessary uses of module.h
x86/mm: Audit and remove any unnecessary uses of module.h
x86: Don't use module.h just for AUTHOR / LICENSE tags
1/ Replace pcommit with ADR / directed-flushing:
The pcommit instruction, which has not shipped on any product, is
deprecated. Instead, the requirement is that platforms implement either
ADR, or provide one or more flush addresses per nvdimm. ADR
(Asynchronous DRAM Refresh) flushes data in posted write buffers to the
memory controller on a power-fail event. Flush addresses are defined in
ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure:
"Flush Hint Address Structure". A flush hint is an mmio address that
when written and fenced assures that all previous posted writes
targeting a given dimm have been flushed to media.
2/ On-demand ARS (address range scrub):
Linux uses the results of the ACPI ARS commands to track bad blocks
in pmem devices. When latent errors are detected we re-scrub the media
to refresh the bad block list, userspace can also request a re-scrub at
any time.
3/ Support for the Microsoft DSM (device specific method) command format.
4/ Support for EDK2/OVMF virtual disk device memory ranges.
5/ Various fixes and cleanups across the subsystem.
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Merge tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
- Replace pcommit with ADR / directed-flushing.
The pcommit instruction, which has not shipped on any product, is
deprecated. Instead, the requirement is that platforms implement
either ADR, or provide one or more flush addresses per nvdimm.
ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers
to the memory controller on a power-fail event.
Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware
Interface Table (NFIT) sub-structure: "Flush Hint Address Structure".
A flush hint is an mmio address that when written and fenced assures
that all previous posted writes targeting a given dimm have been
flushed to media.
- On-demand ARS (address range scrub).
Linux uses the results of the ACPI ARS commands to track bad blocks
in pmem devices. When latent errors are detected we re-scrub the
media to refresh the bad block list, userspace can also request a
re-scrub at any time.
- Support for the Microsoft DSM (device specific method) command
format.
- Support for EDK2/OVMF virtual disk device memory ranges.
- Various fixes and cleanups across the subsystem.
* tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits)
libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register"
nfit: do an ARS scrub on hitting a latent media error
nfit: move to nfit/ sub-directory
nfit, libnvdimm: allow an ARS scrub to be triggered on demand
libnvdimm: register nvdimm_bus devices with an nd_bus driver
pmem: clarify a debug print in pmem_clear_poison
x86/insn: remove pcommit
Revert "KVM: x86: add pcommit support"
nfit, tools/testing/nvdimm/: unify shutdown paths
libnvdimm: move ->module to struct nvdimm_bus_descriptor
nfit: cleanup acpi_nfit_init calling convention
nfit: fix _FIT evaluation memory leak + use after free
tools/testing/nvdimm: add manufacturing_{date|location} dimm properties
tools/testing/nvdimm: add virtual ramdisk range
acpi, nfit: treat virtual ramdisk SPA as pmem region
pmem: kill __pmem address space
pmem: kill wmb_pmem()
libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes
fs/dax: remove wmb_pmem()
libnvdimm, pmem: flush posted-write queues on shutdown
...
Pull perf fixes from Ingo Molnar:
"This tree contains tooling fixes plus some additions:
- fixes to the vdso2c build environment that Stephen Rothwell is
using for the linux-next build (Arnaldo Carvalho de Melo)
- AVX-512 instruction mappings (Adrian Hunter)
- misc fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "perf tools: event.h needs asm/perf_regs.h"
x86: Make the vdso2c compiler use the host architecture headers
tools build: Fix objtool build with ARCH=x86_64
objtool: Always use host headers
objtool: Use tools/scripts/Makefile.arch to get ARCH and HOSTARCH
tools build: Add HOSTARCH Makefile variable
perf tests kmod-path: Fix build on ubuntu:16.04-x-armhf
perf tools: Add AVX-512 instructions to the new instructions test
perf tools: Add AVX-512 support to the instruction decoder used by Intel PT
x86/insn: Add AVX-512 support to the instruction decoder
x86/insn: perf tools: Fix vcvtph2ps instruction decoding
Pull x86 boot updates from Ingo Molnar:
"The main changes:
- add initial commits to randomize kernel memory section virtual
addresses, enabled via a new kernel option: RANDOMIZE_MEMORY
(Thomas Garnier, Kees Cook, Baoquan He, Yinghai Lu)
- enhance KASLR (RANDOMIZE_BASE) physical memory randomization (Kees
Cook)
- EBDA/BIOS region boot quirk cleanups (Andy Lutomirski, Ingo Molnar)
- misc cleanups/fixes"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Simplify EBDA-vs-BIOS reservation logic
x86/boot: Clarify what x86_legacy_features.reserve_bios_regions does
x86/boot: Reorganize and clean up the BIOS area reservation code
x86/mm: Do not reference phys addr beyond kernel
x86/mm: Add memory hotplug support for KASLR memory randomization
x86/mm: Enable KASLR for vmalloc memory regions
x86/mm: Enable KASLR for physical mapping memory regions
x86/mm: Implement ASLR for kernel memory regions
x86/mm: Separate variable for trampoline PGD
x86/mm: Add PUD VA support for physical mapping
x86/mm: Update physical mapping variable names
x86/mm: Refactor KASLR entropy functions
x86/KASLR: Fix boot crash with certain memory configurations
x86/boot/64: Add forgotten end of function marker
x86/KASLR: Allow randomization below the load address
x86/KASLR: Extend kernel image physical address randomization to addresses larger than 4G
x86/KASLR: Randomize virtual address separately
x86/KASLR: Clarify identity map interface
x86/boot: Refuse to build with data relocations
x86/KASLR, x86/power: Remove x86 hibernation restrictions
The pcommit instruction is being deprecated in favor of either ADR
(asynchronous DRAM refresh: flush-on-power-fail) at the platform level, or
posted-write-queue flush addresses as defined by the ACPI 6.x NFIT (NVDIMM
Firmware Interface Table).
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Add support for Intel's AVX-512 instructions to the instruction decoder.
AVX-512 instructions are documented in Intel Architecture Instruction
Set Extensions Programming Reference (February 2016).
AVX-512 instructions are identified by a EVEX prefix which, for the
purpose of instruction decoding, can be treated as though it were a
4-byte VEX prefix.
Existing instructions which can now accept an EVEX prefix need not be
further annotated in the op code map (x86-opcode-map.txt). In the case
of new instructions, the op code map is updated accordingly.
Also add associated Mask Instructions that are used to manipulate mask
registers used in AVX-512 instructions.
The 'perf tools' instruction decoder is updated in a subsequent patch.
And a representative set of instructions is added to the perf tools new
instructions test in a subsequent patch.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>
Link: http://lkml.kernel.org/r/1469003437-32706-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
vcvtph2ps does not have an immediate operand, so remove the erroneous
'Ib' from its opcode map entry. Add vcvtph2ps to the perf tools new
instructions test to verify it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>
Link: http://lkml.kernel.org/r/1469003437-32706-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
struct thread_info is a legacy mess. To prepare for its partial removal,
move thread_info::addr_limit out.
As an added benefit, this way is simpler.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/15bee834d09402b47ac86f2feccdf6529f9bc5b0.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig. The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.
Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed. Build testing
revealed a couple implicit header usage issues that were fixed.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160714001901.31603-5-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
People complained about ARCH_HWEIGHT_CFLAGS and how it throws a wrench
into kcov, lto, etc, experimentations.
Add asm versions for __sw_hweight{32,64}() and do explicit saving and
restoring of clobbered registers. This gets rid of the special calling
convention. We get to call those functions on !X86_FEATURE_POPCNT CPUs.
We still need to hardcode POPCNT and register operands as some old gas
versions which we support, do not know about POPCNT.
Btw, remove redundant REX prefix from 32-bit POPCNT because alternatives
can do padding now.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1464605787-20603-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 asm updates from Ingo Molnar:
"The main changes in this cycle were:
- MSR access API fixes and enhancements (Andy Lutomirski)
- early exception handling improvements (Andy Lutomirski)
- user-space FS/GS prctl usage fixes and improvements (Andy
Lutomirski)
- Remove the cpu_has_*() APIs and replace them with equivalents
(Borislav Petkov)
- task switch micro-optimization (Brian Gerst)
- 32-bit entry code simplification (Denys Vlasenko)
- enhance PAT handling in enumated CPUs (Toshi Kani)
... and lots of other cleanups/fixlets"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
x86/arch_prctl/64: Restore accidentally removed put_cpu() in ARCH_SET_GS
x86/entry/32: Remove asmlinkage_protect()
x86/entry/32: Remove GET_THREAD_INFO() from entry code
x86/entry, sched/x86: Don't save/restore EFLAGS on task switch
x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs
selftests/x86/ldt_gdt: Test set_thread_area() deletion of an active segment
x86/tls: Synchronize segment registers in set_thread_area()
x86/asm/64: Rename thread_struct's fs and gs to fsbase and gsbase
x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization
x86/segments/64: When load_gs_index fails, clear the base
x86/segments/64: When loadsegment(fs, ...) fails, clear the base
x86/asm: Make asm/alternative.h safe from assembly
x86/asm: Stop depending on ptrace.h in alternative.h
x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall()
x86/asm: Make sure verify_cpu() has a good stack
x86/extable: Add a comment about early exception handlers
x86/msr: Set the return value to zero when native_rdmsr_safe() fails
x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y
x86/paravirt: Add paravirt_{read,write}_msr()
x86/msr: Carry on after a non-"safe" MSR access fails
...
3387a535ce ("x86/asm: Create stack frames in rwsem functions") has
added FRAME_{BEGIN,END} annotations to rwsem asm stubs. The patch
which has added call_rwsem_down_write_failed_killable() was based on an
older tree so it didn't know about annotations. Let's add them.
This addresses the following objtool warning:
arch/x86/lib/rwsem.o: warning: objtool: call_rwsem_down_write_failed_killable()+0xe: call without frame pointer save/setup
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1460541432-21631-1-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
which uses the same fast path as __down_write() except it falls back to
call_rwsem_down_write_failed_killable() slow path and return -EINTR if
killed. To prevent from code duplication extract the skeleton of
__down_write() into a helper macro which just takes the semaphore
and the slow path function to be called.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Signed-off-by: Jason Low <jason.low2@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1460041951-22347-11-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kcov provides code coverage collection for coverage-guided fuzzing
(randomized testing). Coverage-guided fuzzing is a testing technique
that uses coverage feedback to determine new interesting inputs to a
system. A notable user-space example is AFL
(http://lcamtuf.coredump.cx/afl/). However, this technique is not
widely used for kernel testing due to missing compiler and kernel
support.
kcov does not aim to collect as much coverage as possible. It aims to
collect more or less stable coverage that is function of syscall inputs.
To achieve this goal it does not collect coverage in soft/hard
interrupts and instrumentation of some inherently non-deterministic or
non-interesting parts of kernel is disbled (e.g. scheduler, locking).
Currently there is a single coverage collection mode (tracing), but the
API anticipates additional collection modes. Initially I also
implemented a second mode which exposes coverage in a fixed-size hash
table of counters (what Quentin used in his original patch). I've
dropped the second mode for simplicity.
This patch adds the necessary support on kernel side. The complimentary
compiler support was added in gcc revision 231296.
We've used this support to build syzkaller system call fuzzer, which has
found 90 kernel bugs in just 2 months:
https://github.com/google/syzkaller/wiki/Found-Bugs
We've also found 30+ bugs in our internal systems with syzkaller.
Another (yet unexplored) direction where kcov coverage would greatly
help is more traditional "blob mutation". For example, mounting a
random blob as a filesystem, or receiving a random blob over wire.
Why not gcov. Typical fuzzing loop looks as follows: (1) reset
coverage, (2) execute a bit of code, (3) collect coverage, repeat. A
typical coverage can be just a dozen of basic blocks (e.g. an invalid
input). In such context gcov becomes prohibitively expensive as
reset/collect coverage steps depend on total number of basic
blocks/edges in program (in case of kernel it is about 2M). Cost of
kcov depends only on number of executed basic blocks/edges. On top of
that, kernel requires per-thread coverage because there are always
background threads and unrelated processes that also produce coverage.
With inlined gcov instrumentation per-thread coverage is not possible.
kcov exposes kernel PCs and control flow to user-space which is
insecure. But debugfs should not be mapped as user accessible.
Based on a patch by Quentin Casasnovas.
[akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode']
[akpm@linux-foundation.org: unbreak allmodconfig]
[akpm@linux-foundation.org: follow x86 Makefile layout standards]
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Tavis Ormandy <taviso@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@google.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: David Drysdale <drysdale@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull 'objtool' stack frame validation from Ingo Molnar:
"This tree adds a new kernel build-time object file validation feature
(ONFIG_STACK_VALIDATION=y): kernel stack frame correctness validation.
It was written by and is maintained by Josh Poimboeuf.
The motivation: there's a category of hard to find kernel bugs, most
of them in assembly code (but also occasionally in C code), that
degrades the quality of kernel stack dumps/backtraces. These bugs are
hard to detect at the source code level. Such bugs result in
incorrect/incomplete backtraces most of time - but can also in some
rare cases result in crashes or other undefined behavior.
The build time correctness checking is done via the new 'objtool'
user-space utility that was written for this purpose and which is
hosted in the kernel repository in tools/objtool/. The tool's (very
simple) UI and source code design is shaped after Git and perf and
shares quite a bit of infrastructure with tools/perf (which tooling
infrastructure sharing effort got merged via perf and is already
upstream). Objtool follows the well-known kernel coding style.
Objtool does not try to check .c or .S files, it instead analyzes the
resulting .o generated machine code from first principles: it decodes
the instruction stream and interprets it. (Right now objtool supports
the x86-64 architecture.)
From tools/objtool/Documentation/stack-validation.txt:
"The kernel CONFIG_STACK_VALIDATION option enables a host tool named
objtool which runs at compile time. It has a "check" subcommand
which analyzes every .o file and ensures the validity of its stack
metadata. It enforces a set of rules on asm code and C inline
assembly code so that stack traces can be reliable.
Currently it only checks frame pointer usage, but there are plans to
add CFI validation for C files and CFI generation for asm files.
For each function, it recursively follows all possible code paths
and validates the correct frame pointer state at each instruction.
It also follows code paths involving special sections, like
.altinstructions, __jump_table, and __ex_table, which can add
alternative execution paths to a given instruction (or set of
instructions). Similarly, it knows how to follow switch statements,
for which gcc sometimes uses jump tables."
When this new kernel option is enabled (it's disabled by default), the
tool, if it finds any suspicious assembly code pattern, outputs
warnings in compiler warning format:
warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch
warning: objtool: cik_tiling_mode_table_init()+0x6ce: call without frame pointer save/setup
warning: objtool:__schedule()+0x3c0: duplicate frame pointer save
warning: objtool:__schedule()+0x3fd: sibling call from callable instruction with changed frame pointer
... so that scripts that pick up compiler warnings will notice them.
All known warnings triggered by the tool are fixed by the tree, most
of the commits in fact prepare the kernel to be warning-free. Most of
them are bugfixes or cleanups that stand on their own, but there are
also some annotations of 'special' stack frames for justified cases
such entries to JIT-ed code (BPF) or really special boot time code.
There are two other long-term motivations behind this tool as well:
- To improve the quality and reliability of kernel stack frames, so
that they can be used for optimized live patching.
- To create independent infrastructure to check the correctness of
CFI stack frames at build time. CFI debuginfo is notoriously
unreliable and we cannot use it in the kernel as-is without extra
checking done both on the kernel side and on the build side.
The quality of kernel stack frames matters to debuggability as well,
so IMO we can merge this without having to consider the live patching
or CFI debuginfo angle"
* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
objtool: Only print one warning per function
objtool: Add several performance improvements
tools: Copy hashtable.h into tools directory
objtool: Fix false positive warnings for functions with multiple switch statements
objtool: Rename some variables and functions
objtool: Remove superflous INIT_LIST_HEAD
objtool: Add helper macros for traversing instructions
objtool: Fix false positive warnings related to sibling calls
objtool: Compile with debugging symbols
objtool: Detect infinite recursion
objtool: Prevent infinite recursion in noreturn detection
objtool: Detect and warn if libelf is missing and don't break the build
tools: Support relative directory path for 'O='
objtool: Support CROSS_COMPILE
x86/asm/decoder: Use explicitly signed chars
objtool: Enable stack metadata validation on 64-bit x86
objtool: Add CONFIG_STACK_VALIDATION option
objtool: Add tool to perform compile-time stack metadata validation
x86/kprobes: Mark kretprobe_trampoline() stack frame as non-standard
sched: Always inline context_switch()
...
Pull networking updates from David Miller:
"Highlights:
1) Support more Realtek wireless chips, from Jes Sorenson.
2) New BPF types for per-cpu hash and arrap maps, from Alexei
Starovoitov.
3) Make several TCP sysctls per-namespace, from Nikolay Borisov.
4) Allow the use of SO_REUSEPORT in order to do per-thread processing
of incoming TCP/UDP connections. The muxing can be done using a
BPF program which hashes the incoming packet. From Craig Gallek.
5) Add a multiplexer for TCP streams, to provide a messaged based
interface. BPF programs can be used to determine the message
boundaries. From Tom Herbert.
6) Add 802.1AE MACSEC support, from Sabrina Dubroca.
7) Avoid factorial complexity when taking down an inetdev interface
with lots of configured addresses. We were doing things like
traversing the entire address less for each address removed, and
flushing the entire netfilter conntrack table for every address as
well.
8) Add and use SKB bulk free infrastructure, from Jesper Brouer.
9) Allow offloading u32 classifiers to hardware, and implement for
ixgbe, from John Fastabend.
10) Allow configuring IRQ coalescing parameters on a per-queue basis,
from Kan Liang.
11) Extend ethtool so that larger link mode masks can be supported.
From David Decotigny.
12) Introduce devlink, which can be used to configure port link types
(ethernet vs Infiniband, etc.), port splitting, and switch device
level attributes as a whole. From Jiri Pirko.
13) Hardware offload support for flower classifiers, from Amir Vadai.
14) Add "Local Checksum Offload". Basically, for a tunneled packet
the checksum of the outer header is 'constant' (because with the
checksum field filled into the inner protocol header, the payload
of the outer frame checksums to 'zero'), and we can take advantage
of that in various ways. From Edward Cree"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits)
bonding: fix bond_get_stats()
net: bcmgenet: fix dma api length mismatch
net/mlx4_core: Fix backward compatibility on VFs
phy: mdio-thunder: Fix some Kconfig typos
lan78xx: add ndo_get_stats64
lan78xx: handle statistics counter rollover
RDS: TCP: Remove unused constant
RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket
net: smc911x: convert pxa dma to dmaengine
team: remove duplicate set of flag IFF_MULTICAST
bonding: remove duplicate set of flag IFF_MULTICAST
net: fix a comment typo
ethernet: micrel: fix some error codes
ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it
bpf, dst: add and use dst_tclassid helper
bpf: make skb->tc_classid also readable
net: mvneta: bm: clarify dependencies
cls_bpf: reset class and reuse major in da
ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c
ldmvsw: Add ldmvsw.c driver code
...
Returning a 'bool' was very unpopular. Doubly so because the
code was just wrong (returning zero for true, one for false;
great for shell programming, not so good for C).
Change return type to "int". Keep zero as the success indicator
because it matches other similar code and people may be more
comfortable writing:
if (memcpy_mcsafe(to, from, count)) {
printk("Sad panda, copy failed\n");
...
}
Make the failure return value -EFAULT for now.
Reported by: Mika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mika.penttila@nextfour.com
Fixes: 92b0729c34 ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Link: http://lkml.kernel.org/r/695f14233fa7a54fcac4406c706d7fec228e3f4c.1457993040.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 boot updates from Ingo Molnar:
"Early command line options parsing enhancements from Dave Hansen, plus
minor cleanups and enhancements"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Remove unused 'is_big_kernel' variable
x86/boot: Use proper array element type in memset() size calculation
x86/boot: Pass in size to early cmdline parsing
x86/boot: Simplify early command line parsing
x86/boot: Fix early command-line parsing when partial word matches
x86/boot: Fix early command-line parsing when matching at end
x86/boot: Simplify kernel load address alignment check
x86/boot: Micro-optimize reset_early_page_tables()
Pull x86 asm updates from Ingo Molnar:
"This is another big update. Main changes are:
- lots of x86 system call (and other traps/exceptions) entry code
enhancements. In particular the complex parts of the 64-bit entry
code have been migrated to C code as well, and a number of dusty
corners have been refreshed. (Andy Lutomirski)
- vDSO special mapping robustification and general cleanups (Andy
Lutomirski)
- cpufeature refactoring, cleanups and speedups (Borislav Petkov)
- lots of other changes ..."
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
x86/cpufeature: Enable new AVX-512 features
x86/entry/traps: Show unhandled signal for i386 in do_trap()
x86/entry: Call enter_from_user_mode() with IRQs off
x86/entry/32: Change INT80 to be an interrupt gate
x86/entry: Improve system call entry comments
x86/entry: Remove TIF_SINGLESTEP entry work
x86/entry/32: Add and check a stack canary for the SYSENTER stack
x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup
x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed
x86/entry: Vastly simplify SYSENTER TF (single-step) handling
x86/entry/traps: Clear DR6 early in do_debug() and improve the comment
x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions
x86/entry/32: Restore FLAGS on SYSEXIT
x86/entry/32: Filter NT and speed up AC filtering in SYSENTER
x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
selftests/x86: In syscall_nt, test NT|TF as well
x86/asm-offsets: Remove PARAVIRT_enabled
x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled
uprobes: __create_xol_area() must nullify xol_mapping.fault
x86/cpufeature: Create a new synthetic cpu capability for machine check recovery
...
Pull RAS updates from Ingo Molnar:
"Various RAS updates:
- AMD MCE support updates for future CPUs, fixes and 'SMCA' (Scalable
MCA) error decoding support (Aravind Gopalakrishnan)
- x86 memcpy_mcsafe() support, to enable smart(er) hardware error
recovery in NVDIMM drivers, based on an extension of the x86
exception handling code. (Tony Luck)"
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
EDAC/sb_edac: Fix computation of channel address
x86/mm, x86/mce: Add memcpy_mcsafe()
x86/mce/AMD: Document some functionality
x86/mce: Clarify comments regarding deferred error
x86/mce/AMD: Fix logic to obtain block address
x86/mce/AMD, EDAC: Enable error decoding of Scalable MCA errors
x86/mce: Move MCx_CONFIG MSR definitions
x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries
x86/mm: Expand the exception table logic to allow new handling options
x86/mce/AMD: Set MCAX Enable bit
x86/mce/AMD: Carve out threshold block preparation
x86/mce/AMD: Fix LVT offset configuration for thresholding
x86/mce/AMD: Reduce number of blocks scanned per bank
x86/mce/AMD: Do not perform shared bank check for future processors
x86/mce: Fix order of AMD MCE init function call
This patch updates csum_ipv6_magic so that it correctly recognizes that
protocol is a unsigned 8 bit value.
This will allow us to better understand what limitations may or may not be
present in how we handle the data. For example there are a number of
places that call htonl on the protocol value. This is likely not necessary
and can be replaced with a multiplication by ntohl(1) which will be
converted to a shift by the compiler.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We do use this_cpu_ptr(&cpu_tss) as a cacheline-aligned, seldomly
accessed per-cpu var as the MONITORX target in delay_mwaitx(). However,
when called in preemptible context, this_cpu_ptr -> smp_processor_id() ->
debug_smp_processor_id() fires:
BUG: using smp_processor_id() in preemptible [00000000] code: udevd/312
caller is delay_mwaitx+0x40/0xa0
But we don't care about that check - we only need cpu_tss as a MONITORX
target and it doesn't really matter which CPU's var we're touching as
we're going idle anyway. Fix that.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: spg_linux_kernel@amd.com
Link: http://lkml.kernel.org/r/20160309205622.GG6564@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make use of the EXTABLE_FAULT exception table entries to write
a kernel copy routine that doesn't crash the system if it
encounters a machine check. Prime use case for this is to copy
from large arrays of non-volatile memory used as storage.
We have to use an unrolled copy loop for now because current
hardware implementations treat a machine check in "rep mov"
as fatal. When that is fixed we can simplify.
Return type is a "bool". True means that we copied OK, false means
that it didn't.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@gmail.com>
Link: http://lkml.kernel.org/r/a44e1055efc2d2a9473307b22c91caa437aa3f8b.1456439214.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When running objtool on a ppc64le host to analyze x86 binaries, it
reports a lot of false warnings like:
ipc/compat_mq.o: warning: objtool: compat_SyS_mq_open()+0x91: can't find jump dest instruction at .text+0x3a5
The warnings are caused by the x86 instruction decoder setting the wrong
value for the jump instruction's immediate field because it assumes that
"char == signed char", which isn't true for all architectures. When
converting char to int, gcc sign-extends on x86 but doesn't sign-extend
on ppc64le.
According to the gcc man page, that's a feature, not a bug:
> Each kind of machine has a default for what "char" should be. It is
> either like "unsigned char" by default or like "signed char" by
> default.
>
> Ideally, a portable program should always use "signed char" or
> "unsigned char" when it depends on the signedness of an object.
Conform to the "standards" by changing the "char" casts to "signed
char". This results in no actual changes to the object code on x86.
Note: the x86 decoder now lives in three different locations in the
kernel tree, which are all kept in sync via makefile checks and
warnings: in-kernel, perf, and objtool. This fixes all three locations.
Eventually we should probably try to at least converge the two separate
"tools" locations into a single shared location.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9dd4161719b20e6def9564646d68bfbe498c549f.1456962210.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
rwsem.S has several callable non-leaf functions which don't honor
CONFIG_FRAME_POINTER, which can result in bad stack traces.
Create stack frames for them when CONFIG_FRAME_POINTER is enabled.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/ad0932bbead975b15f9578e4f2cf2ee5961eb840.1453405861.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Data corruption issues were observed in tests which initiated
a system crash/reset while accessing BTT devices. This problem
is reproducible.
The BTT driver calls pmem_rw_bytes() to update data in pmem
devices. This interface calls __copy_user_nocache(), which
uses non-temporal stores so that the stores to pmem are
persistent.
__copy_user_nocache() uses non-temporal stores when a request
size is 8 bytes or larger (and is aligned by 8 bytes). The
BTT driver updates the BTT map table, which entry size is
4 bytes. Therefore, updates to the map table entries remain
cached, and are not written to pmem after a crash.
Change __copy_user_nocache() to use non-temporal store when
a request size is 4 bytes. The change extends the current
byte-copy path for a less-than-8-bytes request, and does not
add any overhead to the regular path.
Reported-and-tested-by: Micah Parrish <micah.parrish@hpe.com>
Reported-and-tested-by: Brian Boylston <brian.boylston@hpe.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: <stable@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/1455225857-12039-3-git-send-email-toshi.kani@hpe.com
[ Small readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We will use this in a few patches to implement tests for early parsing.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
[ Aligned args properly. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225243.5CC47EB6@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
__cmdline_find_option_bool() tries to account for both NULL-terminated
and non-NULL-terminated strings. It keeps 'pos' to look for the end of
the buffer and also looks for '!c' in a bunch of places to look for NULL
termination.
But, it also calls strlen(). You can't call strlen on a
non-NULL-terminated string.
If !strlen(cmdline), then cmdline[0]=='\0'. In that case, we will go in
to the while() loop, set c='\0', hit st_wordstart, notice !c, and will
immediately return 0.
So, remove the strlen(). It is unnecessary and unsafe.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225241.15365E43@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cmdline_find_option_bool() keeps track of position in two strings:
1. the command-line
2. the option we are searchign for in the command-line
We plow through each character in the command-line one at a time, always
moving forward. We move forward in the option ('opptr') when we match
characters in 'cmdline'. We reset the 'opptr' only when we go in to the
'st_wordstart' state.
But, if we fail to match an option because we see a space
(state=st_wordcmp, *opptr='\0',c=' '), we set state='st_wordskip' and
'break', moving to the next character. But, that move to the next
character is the one *after* the ' '. This means that we will miss a
'st_wordstart' state.
For instance, if we have
cmdline = "foo fool";
and are searching for "fool", we have:
"fool"
opptr = ----^
"foo fool"
c = --------^
We see that 'l' != ' ', set state=st_wordskip, break, and then move 'c', so:
"foo fool"
c = ---------^
and are still in state=st_wordskip. We will stay in wordskip until we
have skipped "fool", thus missing the option we were looking for. This
*only* happens when you have a partially- matching word followed by a
matching one.
To fix this, we always fall *into* the 'st_wordskip' state when we set
it.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225239.8E1DCA58@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The x86 early command line parsing in cmdline_find_option_bool() is
buggy. If it matches a specified 'option' all the way to the end of the
command-line, it will consider it a match.
For instance,
cmdline = "foo";
cmdline_find_option_bool(cmdline, "fool");
will return 1. This is particularly annoying since we have actual FPU
options like "noxsave" and "noxsaves" So, command-line "foo bar noxsave"
will match *BOTH* a "noxsave" and "noxsaves". (This turns out not to be
an actual problem because "noxsave" implies "noxsaves", but it's still
confusing.)
To fix this, we simplify the code and stop tracking 'len'. 'len'
was trying to indicate either the NULL terminator *OR* the end of a
non-NULL-terminated command line at 'COMMAND_LINE_SIZE'. But, each of the
three states is *already* checking 'cmdline' for a NULL terminator.
We _only_ need to check if we have overrun 'COMMAND_LINE_SIZE', and that
we can do without keeping 'len' around.
Also add some commends to clarify what is going on.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225238.9AEB560C@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move them to a separate header and have the following
dependency:
x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h
This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 cpu updates from Ingo Molnar:
"The main changes in this cycle were:
- Improved CPU ID handling code and related enhancements (Borislav
Petkov)
- RDRAND fix (Len Brown)"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Replace RDRAND forced-reseed with simple sanity check
x86/MSR: Chop off lower 32-bit value
x86/cpu: Fix MSR value truncation issue
x86/cpu/amd, kvm: Satisfy guest kernel reads of IC_CFG MSR
kvm: Add accessors for guest CPU's family, model, stepping
x86/cpu: Unify CPU family, model, stepping calculation
For debugging low level code interacting with the CPU it is often
useful to trace the MSR read/writes. This gives a concise summary of
PMU and other operations.
perf has an ad-hoc way to do this using trace_printk, but it's
somewhat limited (and also now spews ugly boot messages when enabled)
Instead define real trace points for all MSR accesses.
This adds three new trace points: read_msr and write_msr and rdpmc.
They also report if the access faulted (if *_safe is used)
This allows filtering and triggering on specific MSR values, which
allows various more advanced debugging techniques.
All the values are well defined in the CPU documentation.
The trace can be post processed with
Documentation/trace/postprocess/decode_msr.py to add symbolic MSR
names to the trace.
I only added it to native MSR accesses in C, not paravirtualized or in
entry*.S (which is not too interesting)
Originally the patch kit moved the MSRs out of line. This uses an
alternative approach recommended by Steven Rostedt of only moving the
trace calls out of line, but open coding the access to the jump label.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1449018060-1742-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add generic functions which calc family, model and stepping from
the CPUID_1.EAX leaf and stick them into the library we have.
Rename those which do call CPUID with the prefix "x86_cpuid" as
suggested by Paolo Bonzini.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1448273546-2567-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add xsavec, xsaves and xrstors to the op code map and the perf tools new
instructions test. To run the test:
$ tools/perf/perf test "x86 ins"
39: Test x86 instruction decoder - new instructions : Ok
Or to see the details:
$ tools/perf/perf test -v "x86 ins" 2>&1 | grep 'xsave\|xrst'
For information about xsavec, xsaves and xrstors, refer the Intel SDM.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add rdpkru and wrpkru to the op code map and the perf tools new
instructions test. In the case of the test, only the bytes can be
tested at the moment since binutils doesn't support the instructions
yet. To run the test:
$ tools/perf/perf test "x86 ins"
39: Test x86 instruction decoder - new instructions : Ok
Or to see the details:
$ tools/perf/perf test -v "x86 ins" 2>&1 | grep pkru
For information about rdpkru and wrpkru, refer the Intel SDM.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-7-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Intel Architecture Instruction Set Extensions Programing Reference (Oct
2014) describes 3 new memory instructions, namely clflushopt, clwb and
pcommit. Add them to the op code map and the perf tools new
instructions test. e.g.
$ tools/perf/perf test "x86 ins"
39: Test x86 instruction decoder - new instructions : Ok
Or to see the details:
$ tools/perf/perf test -v "x86 ins"
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Intel SHA Extensions are explained in the Intel Architecture
Instruction Set Extensions Programing Reference (Oct 2014).
There are 7 new instructions. Add them to the op code map
and the perf tools new instructions test. e.g.
$ tools/perf/perf test "x86 ins"
39: Test x86 instruction decoder - new instructions : Ok
Or to see the details:
$ tools/perf/perf test -v "x86 ins" 2>&1 | grep sha
Committer note:
3 lines of details, for the curious:
$ perf test -v "x86 ins" 2>&1 | grep sha256msg1 | tail -3
Decoded ok: 0f 38 cc 84 08 78 56 34 12 sha256msg1 0x12345678(%rax,%rcx,1),%xmm0
Decoded ok: 0f 38 cc 84 c8 78 56 34 12 sha256msg1 0x12345678(%rax,%rcx,8),%xmm0
Decoded ok: 44 0f 38 cc bc c8 78 56 34 12 sha256msg1 0x12345678(%rax,%rcx,8),%xmm15
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The MPX instructions are presently not described in the SDM
opcode maps, and there are not encoding characters for bnd
registers, address method or operand type. So the kernel
opcode map is using 'Gv' for bnd registers and 'Ev' for
everything else. That is fine because the instruction
decoder does not use that information anyway, except as
an indication that there is a ModR/M byte.
Nevertheless, in some cases the 'Gv' and 'Ev' are the wrong
way around, BNDLDX and BNDSTX have 2 operands not 3, and it
wouldn't hurt to identify the mandatory prefixes.
This has no effect on the decoding of valid instructions,
but the addition of the mandatory prefixes will cause some
invalid instructions to error out that wouldn't have
previously.
Note that perf tools has a copy of the instruction decoder
and provides a test for new instructions which includes MPX
instructions e.g.
$ perf test "x86 ins"
39: Test x86 instruction decoder - new instructions : Ok
Or to see the details:
$ perf test -v "x86 ins"
Commiter notes:
And to see these MPX instructions specifically:
$ perf test -v "x86 ins" 2>&1 | grep bndldx | head -3
Decoded ok: 0f 1a 00 bndldx (%eax),%bnd0
Decoded ok: 0f 1a 05 78 56 34 12 bndldx 0x12345678,%bnd0
Decoded ok: 0f 1a 18 bndldx (%eax),%bnd3
$ perf test -v "x86 ins" 2>&1 | grep bndstx | head -3
Decoded ok: 0f 1b 00 bndstx %bnd0,(%eax)
Decoded ok: 0f 1b 05 78 56 34 12 bndstx %bnd0,0x12345678
Decoded ok: 0f 1b 18 bndstx %bnd3,(%eax)
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
MWAITX can enable a timer and a corresponding timer value
specified in SW P0 clocks. The SW P0 frequency is the same as
TSC. The timer provides an upper bound on how long the
instruction waits before exiting.
This way, a delay function in the kernel can leverage that
MWAITX timer of MWAITX.
When a CPU core executes MWAITX, it will be quiesced in a
waiting phase, diminishing its power consumption. This way, we
can save power in comparison to our default TSC-based delays.
A simple test shows that:
$ cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc
$ sleep 10000s
$ cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc
Results:
* TSC-based default delay: 485115 uWatts average power
* MWAITX-based delay: 252738 uWatts average power
Thus, that's about 240 milliWatts less power consumption. The
test method relies on the support of AMD CPU accumulated power
algorithm in fam15h_power for which patches are forthcoming.
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Suggested-by: Borislav Petkov <bp@suse.de>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Huang Rui <ray.huang@amd.com>
[ Fix delay truncation. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Andreas Herrmann <herrmann.der.user@gmail.com>
Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Jacob Shin <jacob.w.shin@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Li <tony.li@amd.com>
Link: http://lkml.kernel.org/r/1438744732-1459-3-git-send-email-ray.huang@amd.com
Link: http://lkml.kernel.org/r/1439201994-28067-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
rdtsc_barrier(); rdtsc() is an unnecessary mouthful and requires
more thought than should be necessary. Add an rdtsc_ordered()
helper and replace the trivial call sites with it.
This should not change generated code. The duplication of the
fence asm is temporary.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/dddbf98a2af53312e9aa73a5a2b1622fe5d6f52b.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that there is no paravirt TSC, the "native" is
inappropriate. The function does RDTSC, so give it the obvious
name: rdtsc().
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/fd43e16281991f096c1e4d21574d9e1402c62d39.1434501121.git.luto@kernel.org
[ Ported it to v4.2-rc1. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As a very minor optimization, delay_tsc() was only using the low
32 bits of the TSC. It's a delay function, so just use the whole
thing.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/bd1a277c71321b67c4794970cb5ace05efe21ab6.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that the ->read_tsc() paravirt hook is gone, rdtscll() is
just a wrapper around native_read_tsc(). Unwrap it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/d2449ae62c1b1fb90195bcfb19ef4a35883a04dc.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 0a196848ca ("perf: Fix arch_perf_out_copy_user default"),
changes copy_from_user_nmi() to return the number of
remaining bytes so that it behave like copy_from_user().
Unfortunately, when the range is outside of the process
memory, the return value is still the number of byte
copied, eg. 0, instead of the remaining bytes.
As all users of copy_from_user_nmi() were modified as
part of commit 0a196848ca, the function should be
fixed to return the total number of bytes if range is
not correct.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435001923-30986-1-git-send-email-ydroneaud@opteya.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 core updates from Ingo Molnar:
"There were so many changes in the x86/asm, x86/apic and x86/mm topics
in this cycle that the topical separation of -tip broke down somewhat -
so the result is a more traditional architecture pull request,
collected into the 'x86/core' topic.
The topics were still maintained separately as far as possible, so
bisectability and conceptual separation should still be pretty good -
but there were a handful of merge points to avoid excessive
dependencies (and conflicts) that would have been poorly tested in the
end.
The next cycle will hopefully be much more quiet (or at least will
have fewer dependencies).
The main changes in this cycle were:
* x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
Gleixner)
- This is the second and most intrusive part of changes to the x86
interrupt handling - full conversion to hierarchical interrupt
domains:
[IOAPIC domain] -----
|
[MSI domain] --------[Remapping domain] ----- [ Vector domain ]
| (optional) |
[HPET MSI domain] ----- |
|
[DMAR domain] -----------------------------
|
[Legacy domain] -----------------------------
This now reflects the actual hardware and allowed us to distangle
the domain specific code from the underlying parent domain, which
can be optional in the case of interrupt remapping. It's a clear
separation of functionality and removes quite some duct tape
constructs which plugged the remap code between ioapic/msi/hpet
and the vector management.
- Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
injection into guests (Feng Wu)
* x86/asm changes:
- Tons of cleanups and small speedups, micro-optimizations. This
is in preparation to move a good chunk of the low level entry
code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
Brian Gerst)
- Moved all system entry related code to a new home under
arch/x86/entry/ (Ingo Molnar)
- Removal of the fragile and ugly CFI dwarf debuginfo annotations.
Conversion to C will reintroduce many of them - but meanwhile
they are only getting in the way, and the upstream kernel does
not rely on them (Ingo Molnar)
- NOP handling refinements. (Borislav Petkov)
* x86/mm changes:
- Big PAT and MTRR rework: making the code more robust and
preparing to phase out exposing direct MTRR interfaces to drivers -
in favor of using PAT driven interfaces (Toshi Kani, Luis R
Rodriguez, Borislav Petkov)
- New ioremap_wt()/set_memory_wt() interfaces to support
Write-Through cached memory mappings. This is especially
important for good performance on NVDIMM hardware (Toshi Kani)
* x86/ras changes:
- Add support for deferred errors on AMD (Aravind Gopalakrishnan)
This is an important RAS feature which adds hardware support for
poisoned data. That means roughly that the hardware marks data
which it has detected as corrupted but wasn't able to correct, as
poisoned data and raises an APIC interrupt to signal that in the
form of a deferred error. It is the OS's responsibility then to
take proper recovery action and thus prolonge system lifetime as
far as possible.
- Add support for Intel "Local MCE"s: upcoming CPUs will support
CPU-local MCE interrupts, as opposed to the traditional system-
wide broadcasted MCE interrupts (Ashok Raj)
- Misc cleanups (Borislav Petkov)
* x86/platform changes:
- Intel Atom SoC updates
... and lots of other cleanups, fixlets and other changes - see the
shortlog and the Git log for details"
* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
x86/hpet: Use proper hpet device number for MSI allocation
x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
genirq: Prevent crash in irq_move_irq()
genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
iommu, x86: Properly handle posted interrupts for IOMMU hotplug
iommu, x86: Provide irq_remapping_cap() interface
iommu, x86: Setup Posted-Interrupts capability for Intel iommu
iommu, x86: Add cap_pi_support() to detect VT-d PI capability
iommu, x86: Avoid migrating VT-d posted interrupts
iommu, x86: Save the mode (posted or remapped) of an IRTE
iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
iommu: dmar: Provide helper to copy shared irte fields
iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
iommu: Add new member capability to struct irq_remap_ops
x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
...
Pull x86 FPU updates from Ingo Molnar:
"This tree contains two main changes:
- The big FPU code rewrite: wide reaching cleanups and reorganization
that pulls all the FPU code together into a clean base in
arch/x86/fpu/.
The resulting code is leaner and faster, and much easier to
understand. This enables future work to further simplify the FPU
code (such as removing lazy FPU restores).
By its nature these changes have a substantial regression risk: FPU
code related bugs are long lived, because races are often subtle
and bugs mask as user-space failures that are difficult to track
back to kernel side backs. I'm aware of no unfixed (or even
suspected) FPU related regression so far.
- MPX support rework/fixes. As this is still not a released CPU
feature, there were some buglets in the code - should be much more
robust now (Dave Hansen)"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (250 commits)
x86/fpu: Fix double-increment in setup_xstate_features()
x86/mpx: Allow 32-bit binaries on 64-bit kernels again
x86/mpx: Do not count MPX VMAs as neighbors when unmapping
x86/mpx: Rewrite the unmap code
x86/mpx: Support 32-bit binaries on 64-bit kernels
x86/mpx: Use 32-bit-only cmpxchg() for 32-bit apps
x86/mpx: Introduce new 'directory entry' to 'addr' helper function
x86/mpx: Add temporary variable to reduce masking
x86: Make is_64bit_mm() widely available
x86/mpx: Trace allocation of new bounds tables
x86/mpx: Trace the attempts to find bounds tables
x86/mpx: Trace entry to bounds exception paths
x86/mpx: Trace #BR exceptions
x86/mpx: Introduce a boot-time disable flag
x86/mpx: Restrict the mmap() size check to bounds tables
x86/mpx: Remove redundant MPX_BNDCFG_ADDR_MASK
x86/mpx: Clean up the code by not passing a task pointer around when unnecessary
x86/mpx: Use the new get_xsave_field_ptr()API
x86/fpu/xstate: Wrap get_xsave_addr() to make it safer
x86/fpu/xstate: Fix up bad get_xsave_addr() assumptions
...
preempt_schedule_context() is a tracing safe preemption point but it's
only used when CONFIG_CONTEXT_TRACKING=y. Other configs have tracing
recursion issues since commit:
b30f0e3ffe ("sched/preempt: Optimize preemption operations on __schedule() callers")
introduced function based preemp_count_*() ops.
Lets make it available on all configs and give it a more appropriate
name for its new position.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433432349-1021-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
These are all calling x86 entry code functions, so move them close
to other entry code.
Change lib-y to obj-y: there's no real difference between the two
as we don't really drop any of them during the linking stage, and
obj-y is the more common approach for core kernel object code.
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
So the dwarf2 annotations in low level assembly code have
become an increasing hindrance: unreadable, messy macros
mixed into some of the most security sensitive code paths
of the Linux kernel.
These debug info annotations don't even buy the upstream
kernel anything: dwarf driven stack unwinding has caused
problems in the past so it's out of tree, and the upstream
kernel only uses the much more robust framepointers based
stack unwinding method.
In addition to that there's a steady, slow bitrot going
on with these annotations, requiring frequent fixups.
There's no tooling and no functionality upstream that
keeps it correct.
So burn down the sick forest, allowing new, healthier growth:
27 files changed, 350 insertions(+), 1101 deletions(-)
Someone who has the willingness and time to do this
properly can attempt to reintroduce dwarf debuginfo in x86
assembly code plus dwarf unwinding from first principles,
with the following conditions:
- it should be maximally readable, and maximally low-key to
'ordinary' code reading and maintenance.
- find a build time method to insert dwarf annotations
automatically in the most common cases, for pop/push
instructions that manipulate the stack pointer. This could
be done for example via a preprocessing step that just
looks for common patterns - plus special annotations for
the few cases where we want to depart from the default.
We have hundreds of CFI annotations, so automating most of
that makes sense.
- it should come with build tooling checks that ensure that
CFI annotations are sensible. We've seen such efforts from
the framepointer side, and there's no reason it couldn't be
done on the dwarf side.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We already have fpu/types.h, move i387.h to fpu/api.h.
The file name has become a misnomer anyway: it offers generic FPU APIs,
but is not limited to i387 functionality.
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull it up into the header and kill duplicate versions.
Separately, both macros are identical:
35948b2bd3431aee7149e85cfe4becbc /tmp/a
35948b2bd3431aee7149e85cfe4becbc /tmp/b
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431538944-27724-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit cae2a173fe ("x86: clean up/fix 'copy_in_user()' tail zeroing")
fixed the failure case tail zeroing of one special case of the x86-64
generic user-copy routine, namely when used for the user-to-user case
("copy_in_user()").
But in the process it broke an even more unusual case: using the user
copy routine for kernel-to-kernel copying.
Now, normally kernel-kernel copies are obviously done using memcpy(),
but we have a couple of special cases when we use the user-copy
functions. One is when we pass a kernel buffer to a regular user-buffer
routine, using set_fs(KERNEL_DS). That's a "normal" case, and continued
to work fine, because it never takes any faults (with the possible
exception of a silent and successful vmalloc fault).
But Jan Beulich pointed out another, very unusual, special case: when we
use the user-copy routines not because it's a path that expects a user
pointer, but for a couple of ftrace/kgdb cases that want to do a kernel
copy, but do so using "unsafe" buffers, and use the user-copy routine to
gracefully handle faults. IOW, for probe_kernel_write().
And that broke for the case of a faulting kernel destination, because we
saw the kernel destination and wanted to try to clear the tail of the
buffer. Which doesn't work, since that's what faults.
This only triggers for things like kgdb and ftrace users (eg trying
setting a breakpoint on read-only memory), but it's definitely a bug.
The fix is to not compare against the kernel address start (TASK_SIZE),
but instead use the same limits "access_ok()" uses.
Reported-and-tested-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org # 4.0
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 asm changes from Ingo Molnar:
"There were lots of changes in this development cycle:
- over 100 separate cleanups, restructuring changes, speedups and
fixes in the x86 system call, irq, trap and other entry code, part
of a heroic effort to deobfuscate a decade old spaghetti asm code
and its C code dependencies (Denys Vlasenko, Andy Lutomirski)
- alternatives code fixes and enhancements (Borislav Petkov)
- simplifications and cleanups to the compat code (Brian Gerst)
- signal handling fixes and new x86 testcases (Andy Lutomirski)
- various other fixes and cleanups
By their nature many of these changes are risky - we tried to test
them well on many different x86 systems (there are no known
regressions), and they are split up finely to help bisection - but
there's still a fair bit of residual risk left so caveat emptor"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (148 commits)
perf/x86/64: Report regs_user->ax too in get_regs_user()
perf/x86/64: Simplify regs_user->abi setting code in get_regs_user()
perf/x86/64: Do report user_regs->cx while we are in syscall, in get_regs_user()
perf/x86/64: Do not guess user_regs->cs, ss, sp in get_regs_user()
x86/asm/entry/32: Tidy up JNZ instructions after TESTs
x86/asm/entry/64: Reduce padding in execve stubs
x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork
x86/asm/entry/64: Simplify jumps in ret_from_fork
x86/asm/entry/64: Remove a redundant jump
x86/asm/entry/64: Optimize [v]fork/clone stubs
x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too
x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat()
x86/asm/entry/64: Use common code for rt_sigreturn() epilogue
x86/asm/entry/64: Add forgotten CFI annotation
x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout
x86/asm/entry/64: Move opportunistic sysret code to syscall code path
x86, selftests: Add sigreturn selftest
x86/alternatives: Guard NOPs optimization
x86/asm/entry: Clear EXTRA_REGS for all executable formats
x86/signal: Remove pax argument from restore_sigcontext
...
The rule for 'copy_from_user()' is that it zeroes the remaining kernel
buffer even when the copy fails halfway, just to make sure that we don't
leave uninitialized kernel memory around. Because even if we check for
errors, some kernel buffers stay around after thge copy (think page
cache).
However, the x86-64 logic for user copies uses a copy_user_generic()
function for all the cases, that set the "zerorest" flag for any fault
on the source buffer. Which meant that it didn't just try to clear the
kernel buffer after a failure in copy_from_user(), it also tried to
clear the destination user buffer for the "copy_in_user()" case.
Not only is that pointless, it also means that the clearing code has to
worry about the tail clearing taking page faults for the user buffer
case. Which is just stupid, since that case shouldn't happen in the
first place.
Get rid of the whole "zerorest" thing entirely, and instead just check
if the destination is in kernel space or not. And then just use
memset() to clear the tail of the kernel buffer if necessary.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
By the nature of the TEST operation, it is often possible to test
a narrower part of the operand:
"testl $3, mem" -> "testb $3, mem",
"testq $3, %rcx" -> "testb $3, %cl"
This results in shorter instructions, because the TEST instruction
has no sign-entending byte-immediate forms unlike other ALU ops.
Note that this change does not create any LCP (Length-Changing Prefix)
stalls, which happen when adding a 0x66 prefix, which happens when
16-bit immediates are used, which changes such TEST instructions:
[test_opcode] [modrm] [imm32]
to:
[0x66] [test_opcode] [modrm] [imm16]
where [imm16] has a *different length* now: 2 bytes instead of 4.
This confuses the decoder and slows down execution.
REX prefixes were carefully designed to almost never hit this case:
adding REX prefix does not change instruction length except MOVABS
and MOV [addr],RAX instruction.
This patch does not add instructions which would use a 0x66 prefix,
code changes in assembly are:
-48 f7 07 01 00 00 00 testq $0x1,(%rdi)
+f6 07 01 testb $0x1,(%rdi)
-48 f7 c1 01 00 00 00 test $0x1,%rcx
+f6 c1 01 test $0x1,%cl
-48 f7 c1 02 00 00 00 test $0x2,%rcx
+f6 c1 02 test $0x2,%cl
-41 f7 c2 01 00 00 00 test $0x1,%r10d
+41 f6 c2 01 test $0x1,%r10b
-48 f7 c1 04 00 00 00 test $0x4,%rcx
+f6 c1 04 test $0x4,%cl
-48 f7 c1 08 00 00 00 test $0x8,%rcx
+f6 c1 08 test $0x8,%cl
Linus further notes:
"There are no stalls from using 8-bit instruction forms.
Now, changing from 64-bit or 32-bit 'test' instructions to 8-bit ones
*could* cause problems if it ends up having forwarding issues, so that
instead of just forwarding the result, you end up having to wait for
it to be stable in the L1 cache (or possibly the register file). The
forwarding from the store buffer is simplest and most reliable if the
read is done at the exact same address and the exact same size as the
write that gets forwarded.
But that's true only if:
(a) the write was very recent and is still in the write queue. I'm
not sure that's the case here anyway.
(b) on at least most Intel microarchitectures, you have to test a
different byte than the lowest one (so forwarding a 64-bit write
to a 8-bit read ends up working fine, as long as the 8-bit read
is of the low 8 bits of the written data).
A very similar issue *might* show up for registers too, not just
memory writes, if you use 'testb' with a high-byte register (where
instead of forwarding the value from the original producer it needs to
go through the register file and then shifted). But it's mainly a
problem for store buffers.
But afaik, the way Denys changed the test instructions, neither of the
above issues should be true.
The real problem for store buffer forwarding tends to be "write 8
bits, read 32 bits". That can be really surprisingly expensive,
because the read ends up having to wait until the write has hit the
cacheline, and we might talk tens of cycles of latency here. But
"write 32 bits, read the low 8 bits" *should* be fast on pretty much
all x86 chips, afaik."
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1425675332-31576-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is a preparatory patch for change in "struct pt_regs"
handling in entry_64.S.
trace_hardirqs*() thunks were (ab)using a part of the
'pt_regs' handling code, namely the SAVE_ARGS/RESTORE_ARGS
macros, to save/restore registers across C function calls.
Since SAVE_ARGS is going to be changed, open-code
register saving/restoring here.
Incidentally, this removes a bit of dead code:
one SAVE_ARGS was used just to emit a CFI annotation,
but it also generated unreachable assembly instructions.
Take a page from thunk_32.S and use push/pop instructions
instead of movq, they are far shorter:
1 or 2 bytes versus 5, and no need for instructions to adjust %rsp:
text data bss dec hex filename
333 40 0 373 175 thunk_64_movq.o
104 40 0 144 90 thunk_64_push_pop.o
[ This is ugly as sin, but we'll fix up the ugliness in the next
patch. I see no point in reordering patches just to avoid an
ugly intermediate state. --Andy ]
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1420927210-19738-4-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/4c979ad604f0f02c5ade3b3da308b53eabd5e198.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
pad instructions and thus make using the alternatives macros more
straightforward and without having to figure out old and new instruction
sizes but have the toolchain figure that out for us.
Furthermore, it optimizes JMPs used so that fetch and decode can be
relieved with smaller versions of the JMPs, where possible.
Some stats:
x86_64 defconfig:
Alternatives sites total: 2478
Total padding added (in Bytes): 6051
The padding is currently done for:
X86_FEATURE_ALWAYS
X86_FEATURE_ERMS
X86_FEATURE_LFENCE_RDTSC
X86_FEATURE_MFENCE_RDTSC
X86_FEATURE_SMAP
This is with the latest version of the patchset. Of course, on each
machine the alternatives sites actually being patched are a proper
subset of the total number.
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Merge tag 'alternatives_padding' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/asm
Pull alternative instructions framework improvements from Borislav Petkov:
"A more involved rework of the alternatives framework to be able to
pad instructions and thus make using the alternatives macros more
straightforward and without having to figure out old and new instruction
sizes but have the toolchain figure that out for us.
Furthermore, it optimizes JMPs used so that fetch and decode can be
relieved with smaller versions of the JMPs, where possible.
Some stats:
x86_64 defconfig:
Alternatives sites total: 2478
Total padding added (in Bytes): 6051
The padding is currently done for:
X86_FEATURE_ALWAYS
X86_FEATURE_ERMS
X86_FEATURE_LFENCE_RDTSC
X86_FEATURE_MFENCE_RDTSC
X86_FEATURE_SMAP
This is with the latest version of the patchset. Of course, on each
machine the alternatives sites actually being patched are a proper
subset of the total number."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make it execute the ERMS version if support is present and we're in the
forward memmove() part and remove the unfolded alternatives section
definition.
Signed-off-by: Borislav Petkov <bp@suse.de>
Make alternatives replace single JMPs instead of whole memset functions,
thus decreasing the amount of instructions copied during patching time
at boot.
While at it, make it use the REP_GOOD version by default which means
alternatives NOP out the JMP to the other versions, as REP_GOOD is set
by default on the majority of relevant x86 processors.
Signed-off-by: Borislav Petkov <bp@suse.de>
Move clear_page() up so that we can get 2-byte forward JMPs when
patching:
apply_alternatives: feat: 3*32+16, old: (ffffffff8130adb0, len: 5), repl: (ffffffff81d0b859, len: 5)
ffffffff8130adb0: alt_insn: 90 90 90 90 90
recompute_jump: new_displ: 0x0000003e
ffffffff81d0b859: rpl_insn: eb 3e 66 66 90
even though the compiler generated 5-byte JMPs which we padded with 5
NOPs.
Also, make the REP_GOOD version be the default as the majority of
machines set REP_GOOD. This way we get to save ourselves the JMP:
old insn VA: 0xffffffff813038b0, CPU feat: X86_FEATURE_REP_GOOD, size: 5, padlen: 0
clear_page:
ffffffff813038b0 <clear_page>:
ffffffff813038b0: e9 0b 00 00 00 jmpq ffffffff813038c0
repl insn: 0xffffffff81cf0e92, size: 0
old insn VA: 0xffffffff813038b0, CPU feat: X86_FEATURE_ERMS, size: 5, padlen: 0
clear_page:
ffffffff813038b0 <clear_page>:
ffffffff813038b0: e9 0b 00 00 00 jmpq ffffffff813038c0
repl insn: 0xffffffff81cf0e92, size: 5
ffffffff81cf0e92: e9 69 2a 61 ff jmpq ffffffff81303900
ffffffff813038b0 <clear_page>:
ffffffff813038b0: e9 69 2a 61 ff jmpq ffffffff8091631e
Signed-off-by: Borislav Petkov <bp@suse.de>
... instead of the semi-version with the spelled out sections.
What is more, make the REP_GOOD version be the default copy_page()
version as the majority of the relevant x86 CPUs do set
X86_FEATURE_REP_GOOD. Thus, copy_page gets compiled to:
ffffffff8130af80 <copy_page>:
ffffffff8130af80: e9 0b 00 00 00 jmpq ffffffff8130af90 <copy_page_regs>
ffffffff8130af85: b9 00 02 00 00 mov $0x200,%ecx
ffffffff8130af8a: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi)
ffffffff8130af8d: c3 retq
ffffffff8130af8e: 66 90 xchg %ax,%ax
ffffffff8130af90 <copy_page_regs>:
...
and after the alternatives have run, the JMP to the old, unrolled
version gets NOPed out:
ffffffff8130af80 <copy_page>:
ffffffff8130af80: 66 66 90 xchg %ax,%ax
ffffffff8130af83: 66 90 xchg %ax,%ax
ffffffff8130af85: b9 00 02 00 00 mov $0x200,%ecx
ffffffff8130af8a: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi)
ffffffff8130af8d: c3 retq
On modern uarches, those NOPs are cheaper than the unconditional JMP
previously.
Signed-off-by: Borislav Petkov <bp@suse.de>
Up until now we had to pay attention to relative JMPs in alternatives
about how their relative offset gets computed so that the jump target
is still correct. Or, as it is the case for near CALLs (opcode e8), we
still have to go and readjust the offset at patching time.
What is more, the static_cpu_has_safe() facility had to forcefully
generate 5-byte JMPs since we couldn't rely on the compiler to generate
properly sized ones so we had to force the longest ones. Worse than
that, sometimes it would generate a replacement JMP which is longer than
the original one, thus overwriting the beginning of the next instruction
at patching time.
So, in order to alleviate all that and make using JMPs more
straight-forward we go and pad the original instruction in an
alternative block with NOPs at build time, should the replacement(s) be
longer. This way, alternatives users shouldn't pay special attention
so that original and replacement instruction sizes are fine but the
assembler would simply add padding where needed and not do anything
otherwise.
As a second aspect, we go and recompute JMPs at patching time so that we
can try to make 5-byte JMPs into two-byte ones if possible. If not, we
still have to recompute the offsets as the replacement JMP gets put far
away in the .altinstr_replacement section leading to a wrong offset if
copied verbatim.
For example, on a locally generated kernel image
old insn VA: 0xffffffff810014bd, CPU feat: X86_FEATURE_ALWAYS, size: 2
__switch_to:
ffffffff810014bd: eb 21 jmp ffffffff810014e0
repl insn: size: 5
ffffffff81d0b23c: e9 b1 62 2f ff jmpq ffffffff810014f2
gets corrected to a 2-byte JMP:
apply_alternatives: feat: 3*32+21, old: (ffffffff810014bd, len: 2), repl: (ffffffff81d0b23c, len: 5)
alt_insn: e9 b1 62 2f ff
recompute_jumps: next_rip: ffffffff81d0b241, tgt_rip: ffffffff810014f2, new_displ: 0x00000033, ret len: 2
converted to: eb 33 90 90 90
and a 5-byte JMP:
old insn VA: 0xffffffff81001516, CPU feat: X86_FEATURE_ALWAYS, size: 2
__switch_to:
ffffffff81001516: eb 30 jmp ffffffff81001548
repl insn: size: 5
ffffffff81d0b241: e9 10 63 2f ff jmpq ffffffff81001556
gets shortened into a two-byte one:
apply_alternatives: feat: 3*32+21, old: (ffffffff81001516, len: 2), repl: (ffffffff81d0b241, len: 5)
alt_insn: e9 10 63 2f ff
recompute_jumps: next_rip: ffffffff81d0b246, tgt_rip: ffffffff81001556, new_displ: 0x0000003e, ret len: 2
converted to: eb 3e 90 90 90
... and so on.
This leads to a net win of around
40ish replacements * 3 bytes savings =~ 120 bytes of I$
on an AMD guest which means some savings of precious instruction cache
bandwidth. The padding to the shorter 2-byte JMPs are single-byte NOPs
which on smart microarchitectures means discarding NOPs at decode time
and thus freeing up execution bandwidth.
Signed-off-by: Borislav Petkov <bp@suse.de>
Up until now we have always paid attention to make sure the length of
the new instruction replacing the old one is at least less or equal to
the length of the old instruction. If the new instruction is longer, at
the time it replaces the old instruction it will overwrite the beginning
of the next instruction in the kernel image and cause your pants to
catch fire.
So instead of having to pay attention, teach the alternatives framework
to pad shorter old instructions with NOPs at buildtime - but only in the
case when
len(old instruction(s)) < len(new instruction(s))
and add nothing in the >= case. (In that case we do add_nops() when
patching).
This way the alternatives user shouldn't have to care about instruction
sizes and simply use the macros.
Add asm ALTERNATIVE* flavor macros too, while at it.
Also, we need to save the pad length in a separate struct alt_instr
member for NOP optimization and the way to do that reliably is to carry
the pad length instead of trying to detect whether we're looking at
single-byte NOPs or at pathological instruction offsets like e9 90 90 90
90, for example, which is a valid instruction.
Thanks to Michael Matz for the great help with toolchain questions.
Signed-off-by: Borislav Petkov <bp@suse.de>
x86 instructions cannot exceed 15 bytes, and the instruction
decoder should enforce that. Prior to 6ba48ff46f, the
instruction length limit was implicitly set to 16, which was an
approximation of 15, but there is currently no limit at all.
Fix MAX_INSN_SIZE (it should be 15, not 16), and fix the decoder
to reject instructions that exceed MAX_INSN_SIZE.
Other than potentially confusing some of the decoder sanity
checks, I'm not aware of any actual problems that omitting this
check would cause, nor am I aware of any practical problems
caused by the MAX_INSN_SIZE error.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Fixes: 6ba48ff46f ("x86: Remove arbitrary instruction size limit ...
Link: http://lkml.kernel.org/r/f8f0bc9b8c58cfd6830f7d88400bf1396cbdcd0f.1422403511.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Recently instrumentation of builtin functions calls was removed from GCC
5.0. To check the memory accessed by such functions, userspace asan
always uses interceptors for them.
So now we should do this as well. This patch declares
memset/memmove/memcpy as weak symbols. In mm/kasan/kasan.c we have our
own implementation of those functions which checks memory before accessing
it.
Default memset/memmove/memcpy now now always have aliases with '__'
prefix. For files that built without kasan instrumentation (e.g.
mm/slub.c) original mem* replaced (via #define) with prefixed variants,
cause we don't want to check memory accesses there.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stephane reported that the PEBS fixup was broken by the recent commit to
the instruction decoder. The thing had an off-by-one which resulted in
not being able to decode the last instruction and always bail.
Reported-by: Stephane Eranian <eranian@google.com>
Fixes: 6ba48ff46f ("x86: Remove arbitrary instruction size limit in instruction decoder")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 3.18
Cc: <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Liang Kan <kan.liang@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20141216104614.GV3337@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull networking updates from David Miller:
1) New offloading infrastructure and example 'rocker' driver for
offloading of switching and routing to hardware.
This work was done by a large group of dedicated individuals, not
limited to: Scott Feldman, Jiri Pirko, Thomas Graf, John Fastabend,
Jamal Hadi Salim, Andy Gospodarek, Florian Fainelli, Roopa Prabhu
2) Start making the networking operate on IOV iterators instead of
modifying iov objects in-situ during transfers. Thanks to Al Viro
and Herbert Xu.
3) A set of new netlink interfaces for the TIPC stack, from Richard
Alpe.
4) Remove unnecessary looping during ipv6 routing lookups, from Martin
KaFai Lau.
5) Add PAUSE frame generation support to gianfar driver, from Matei
Pavaluca.
6) Allow for larger reordering levels in TCP, which are easily
achievable in the real world right now, from Eric Dumazet.
7) Add a variable of napi_schedule that doesn't need to disable cpu
interrupts, from Eric Dumazet.
8) Use a doubly linked list to optimize neigh_parms_release(), from
Nicolas Dichtel.
9) Various enhancements to the kernel BPF verifier, and allow eBPF
programs to actually be attached to sockets. From Alexei
Starovoitov.
10) Support TSO/LSO in sunvnet driver, from David L Stevens.
11) Allow controlling ECN usage via routing metrics, from Florian
Westphal.
12) Remote checksum offload, from Tom Herbert.
13) Add split-header receive, BQL, and xmit_more support to amd-xgbe
driver, from Thomas Lendacky.
14) Add MPLS support to openvswitch, from Simon Horman.
15) Support wildcard tunnel endpoints in ipv6 tunnels, from Steffen
Klassert.
16) Do gro flushes on a per-device basis using a timer, from Eric
Dumazet. This tries to resolve the conflicting goals between the
desired handling of bulk vs. RPC-like traffic.
17) Allow userspace to ask for the CPU upon what a packet was
received/steered, via SO_INCOMING_CPU. From Eric Dumazet.
18) Limit GSO packets to half the current congestion window, from Eric
Dumazet.
19) Add a generic helper so that all drivers set their RSS keys in a
consistent way, from Eric Dumazet.
20) Add xmit_more support to enic driver, from Govindarajulu
Varadarajan.
21) Add VLAN packet scheduler action, from Jiri Pirko.
22) Support configurable RSS hash functions via ethtool, from Eyal
Perry.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1820 commits)
Fix race condition between vxlan_sock_add and vxlan_sock_release
net/macb: fix compilation warning for print_hex_dump() called with skb->mac_header
net/mlx4: Add support for A0 steering
net/mlx4: Refactor QUERY_PORT
net/mlx4_core: Add explicit error message when rule doesn't meet configuration
net/mlx4: Add A0 hybrid steering
net/mlx4: Add mlx4_bitmap zone allocator
net/mlx4: Add a check if there are too many reserved QPs
net/mlx4: Change QP allocation scheme
net/mlx4_core: Use tasklet for user-space CQ completion events
net/mlx4_core: Mask out host side virtualization features for guests
net/mlx4_en: Set csum level for encapsulated packets
be2net: Export tunnel offloads only when a VxLAN tunnel is created
gianfar: Fix dma check map error when DMA_API_DEBUG is enabled
cxgb4/csiostor: Don't use MASTER_MUST for fw_hello call
net: fec: only enable mdio interrupt before phy device link up
net: fec: clear all interrupt events to support i.MX6SX
net: fec: reset fep link status in suspend function
net: sock: fix access via invalid file descriptor
net: introduce helper macro for_each_cmsghdr
...
As there are now no remaining users of arch_fast_hash(), lets kill
it entirely.
This basically reverts commit 71ae8aac3e ("lib: introduce arch
optimized hash library") and follow-up work, that is f.e., commit
237217546d ("lib: hash: follow-up fixups for arch hash"),
commit e3fec2f74f ("lib: Add missing arch generic-y entries for
asm-generic/hash.h") and last but not least commit 6a02652df5
("perf tools: Fix include for non x86 architectures").
Cc: Francesco Fusco <fusco@ntop.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull x86 MPX support from Thomas Gleixner:
"This enables support for x86 MPX.
MPX is a new debug feature for bound checking in user space. It
requires kernel support to handle the bound tables and decode the
bound violating instruction in the trap handler"
* 'x86-mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
asm-generic: Remove asm-generic arch_bprm_mm_init()
mm: Make arch_unmap()/bprm_mm_init() available to all architectures
x86: Cleanly separate use of asm-generic/mm_hooks.h
x86 mpx: Change return type of get_reg_offset()
fs: Do not include mpx.h in exec.c
x86, mpx: Add documentation on Intel MPX
x86, mpx: Cleanup unused bound tables
x86, mpx: On-demand kernel allocation of bounds tables
x86, mpx: Decode MPX instruction to get bound violation information
x86, mpx: Add MPX-specific mmap interface
x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specific
x86, mpx: Add MPX to disabled features
ia64: Sync struct siginfo with general version
mips: Sync struct siginfo with general version
mpx: Extend siginfo structure to include bound violation information
x86, mpx: Rename cfg_reg_u and status_reg
x86: mpx: Give bndX registers actual names
x86: Remove arbitrary instruction size limit in instruction decoder
The current x86 instruction decoder steps along through the
instruction stream but always ensures that it never steps farther
than the largest possible instruction size (MAX_INSN_SIZE).
The MPX code is now going to be doing some decoding of userspace
instructions. We copy those from userspace in to the kernel and
they're obviously completely untrusted coming from userspace. In
addition to the constraint that instructions can only be so long,
we also have to be aware of how long the buffer is that came in
from userspace. This _looks_ to be similar to what the perf and
kprobes is doing, but it's unclear to me whether they are
affected.
The whole reason we need this is that it is perfectly valid to be
executing an instruction within MAX_INSN_SIZE bytes of an
unreadable page. We should be able to gracefully handle short
reads in those cases.
This adds support to the decoder to record how long the buffer
being decoded is and to refuse to "validate" the instruction if
we would have gone over the end of the buffer to decode it.
The kprobes code probably needs to be looked at here a bit more
carefully. This patch still respects the MAX_INSN_SIZE limit
there but the kprobes code does look like it might be able to
be a bit more strict than it currently is.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: x86@kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20141114153957.E6B01535@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Al Viro pointed out that the x86-64 csum_partial_copy_from_user() is
somewhat confused about what it should do on errors, notably it mostly
clears the uncopied end result buffer, but misses that for the initial
alignment case.
All users should check for errors, so it's dubious whether the clearing
is even necessary, and Al also points out that we should probably clean
up the calling conventions, but regardless of any future changes to this
function, the fact that it is inconsistent is just annoying.
So make the __get_user() failure path use the same error exit as all the
other errors do.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 asm updates from Ingo Molnar:
"The changes in this cycle were:
- Speed up the x86 __preempt_schedule() implementation
- Fix/improve low level asm code debug info annotations"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Unwind-annotate thunk_32.S
x86: Improve cmpxchg8b_emu.S
x86: Improve cmpxchg16b_emu.S
x86/lib/Makefile: Remove the unnecessary "+= thunk_64.o"
x86: Speed up ___preempt_schedule*() by using THUNK helpers
- don't include unneeded headers
- drop redundant entry point label
- complete unwind annotations
- use .L prefix on local labels to not clutter the symbol table
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5422917E0200007800038081@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- don't include unneeded headers
- don't open-code PER_CPU_VAR()
- drop redundant entry point label
- complete unwind annotations
- use .L prefix on local label to not clutter the symbol table
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/542290BC020000780003807D@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Trivial. We have "lib-y += thunk_$(BITS).o" at the start, no
need to add thunk_64.o if !CONFIG_X86_32.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140921184232.GB23727@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
___preempt_schedule() does SAVE_ALL/RESTORE_ALL but this is
suboptimal, we do not need to save/restore the callee-saved
register. And we already have arch/x86/lib/thunk_*.S which
implements the similar asm wrappers, so it makes sense to
redefine ___preempt_schedule() as "THUNK ..." and remove
preempt.S altogether.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140921184153.GA23727@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch removes the unused asm/rwlock.h and rwlock.S files.
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1408037251-45918-3-git-send-email-Waiman.Long@hp.com
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull more perf updates from Ingo Molnar:
"A second round of perf updates:
- wide reaching kprobes sanitization and robustization, with the hope
of fixing all 'probe this function crashes the kernel' bugs, by
Masami Hiramatsu.
- uprobes updates from Oleg Nesterov: tmpfs support, corner case
fixes and robustization work.
- perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo
et al:
* Add support to accumulate hist periods (Namhyung Kim)
* various fixes, refactorings and enhancements"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
perf: Differentiate exec() and non-exec() comm events
perf: Fix perf_event_comm() vs. exec() assumption
uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates
perf/documentation: Add description for conditional branch filter
perf/x86: Add conditional branch filtering support
perf/tool: Add conditional branch filter 'cond' to perf record
perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND'
uprobes: Teach copy_insn() to support tmpfs
uprobes: Shift ->readpage check from __copy_insn() to uprobe_register()
perf/x86: Use common PMU interrupt disabled code
perf/ARM: Use common PMU interrupt disabled code
perf: Disable sampled events if no PMU interrupt
perf: Fix use after free in perf_remove_from_context()
perf tools: Fix 'make help' message error
perf record: Fix poll return value propagation
perf tools: Move elide bool into perf_hpp_fmt struct
perf tools: Remove elide setup for SORT_MODE__MEMORY mode
perf tools: Fix "==" into "=" in ui_browser__warning assignment
perf tools: Allow overriding sysfs and proc finding with env var
perf tools: Consider header files outside perf directory in tags target
...
Carve out early cmdline parsing function into .../lib/cmdline.c so it
can be used by early code in the kernel proper as well.
Adapted from arch/x86/boot/cmdline.c.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1400525957-11525-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Due to a typo the msr accessor function introduced in
22085a66c2 didn't have any lasting
effects because they accidentally wrote the old value back.
After c0a639ad0b this at the very least
this causes cpuid limits not to be lifted on some cpus leading to
missing capabilities for those.
Signed-off-by: Andres Freund <andres@anarazel.de>
Link: http://lkml.kernel.org/r/1399598957-7011-2-git-send-email-andres@anarazel.de
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
thunk/restore functions are also used for tracing irqoff etc.
and those are involved in kprobe's exception handling.
Prohibit probing on them to avoid kernel crash.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140417081726.26341.3872.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 LTO changes from Peter Anvin:
"More infrastructure work in preparation for link-time optimization
(LTO). Most of these changes is to make sure symbols accessed from
assembly code are properly marked as visible so the linker doesn't
remove them.
My understanding is that the changes to support LTO are still not
upstream in binutils, but are on the way there. This patchset should
conclude the x86-specific changes, and remaining patches to actually
enable LTO will be fed through the Kbuild tree (other than keeping up
with changes to the x86 code base, of course), although not
necessarily in this merge window"
* 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
Kbuild, lto: Handle basic LTO in modpost
Kbuild, lto: Disable LTO for asm-offsets.c
Kbuild, lto: Add a gcc-ld script to let run gcc as ld
Kbuild, lto: add ld-version and ld-ifversion macros
Kbuild, lto: Drop .number postfixes in modpost
Kbuild, lto, workaround: Don't warn for initcall_reference in modpost
lto: Disable LTO for sys_ni
lto: Handle LTO common symbols in module loader
lto, workaround: Add workaround for initcall reordering
lto: Make asmlinkage __visible
x86, lto: Disable LTO for the x86 VDSO
initconst, x86: Fix initconst mistake in ts5500 code
initconst: Fix initconst mistake in dcdbas
asmlinkage: Make trace_hardirqs_on/off_caller visible
asmlinkage, x86: Fix 32bit memcpy for LTO
asmlinkage Make __stack_chk_failed and memcmp visible
asmlinkage: Mark rwsem functions that can be called from assembler asmlinkage
asmlinkage: Make main_extable_sort_needed visible
asmlinkage, mutex: Mark __visible
asmlinkage: Make trace_hardirq visible
...
Pull x86 hashing changes from Ingo Molnar:
"Small fixes and cleanups to the librarized arch_fast_hash() methods,
used by the net/openvswitch code"
* 'x86-hash-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, hash: Simplify switch, add __init annotation
x86, hash: Swap arguments passed to crc32_u32()
x86, hash: Fix build failure with older binutils
Minor cleanups:
- simplify switch statement
- add __init annotation to setup_arch_fast_hash()
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/530F09CE020000780011FBEF@nat28.tlf.novell.com
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Thomas Graf <tgraf@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
... to match the function's parameters. While reportedly commutative,
using the proper order allows for leveraging the instruction permitting
the source operand to be in memory.
[ hpa: This code originated in the dpdk toolkit. This was a bug in dpdk
which has recently been fixed in part due to an earlier version of
this patch. ]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/530F09B6020000780011FBEB@nat28.tlf.novell.com
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Thomas Graf <tgraf@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Ricardo Neri