Commit Graph

62 Commits

Author SHA1 Message Date
Masahiro Yamada f3a53f7b57 arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig
This becomes much neater in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-06-08 18:56:02 +09:00
Luc Van Oostenryck 1f2f01b122 kbuild: add machine size to CHECKFLAGS
By default, sparse assumes a 64bit machine when compiled on x86-64
and 32bit when compiled on anything else.

This can of course create all sort of problems for the other archs, like
issuing false warnings ('shift too big (32) for type unsigned long'), or
worse, failing to emit legitimate warnings.

Fix this by adding the -m32/-m64 flag, depending on CONFIG_64BIT,
to CHECKFLAGS in the main Makefile (and so for all archs).
Also, remove the now unneeded -m32/-m64 in arch specific Makefiles.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-01 11:36:58 +09:00
Jason A. Donenfeld ad40bdafb4 arm64: support __int128 with clang
Commit fb8722735f ("arm64: support __int128 on gcc 5+") added support
for arm64 __int128 with gcc with a version-conditional, but neglected to
enable this for clang, which in fact appears to support aarch64 __int128.
This commit therefore enables it if the compiler is clang, using the
same type of makefile conditional used elsewhere in the tree.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-24 19:07:55 +01:00
Ard Biesheuvel a257e02579 arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419
Working around Cortex-A53 erratum #843419 involves special handling of
ADRP instructions that end up in the last two instruction slots of a
4k page, or whose output register gets overwritten without having been
read. (Note that the latter instruction sequence is never emitted by
a properly functioning compiler, which is why it is disregarded by the
handling of the same erratum in the bfd.ld linker which we rely on for
the core kernel)

Normally, this gets taken care of by the linker, which can spot such
sequences at final link time, and insert a veneer if the ADRP ends up
at a vulnerable offset. However, linux kernel modules are partially
linked ELF objects, and so there is no 'final link time' other than the
runtime loading of the module, at which time all the static relocations
are resolved.

For this reason, we have implemented the #843419 workaround for modules
by avoiding ADRP instructions altogether, by using the large C model,
and by passing -mpc-relative-literal-loads to recent versions of GCC
that may emit adrp/ldr pairs to perform literal loads. However, this
workaround forces us to keep literal data mixed with the instructions
in the executable .text segment, and literal data may inadvertently
turn into an exploitable speculative gadget depending on the relative
offsets of arbitrary symbols.

So let's reimplement this workaround in a way that allows us to switch
back to the small C model, and to drop the -mpc-relative-literal-loads
GCC switch, by patching affected ADRP instructions at runtime:
- ADRP instructions that do not appear at 4k relative offset 0xff8 or
  0xffc are ignored
- ADRP instructions that are within 1 MB of their target symbol are
  converted into ADR instructions
- remaining ADRP instructions are redirected via a veneer that performs
  the load using an unaffected movn/movk sequence.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: tidied up ADRP -> ADR instruction patching.]
[will: use ULL suffix for 64-bit immediate]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:21:53 +00:00
Andrey Konovalov 9597e74396 kasan, arm64: clean up KASAN_SHADOW_SCALE_SHIFT usage
This is a follow up patch to the series I sent recently that cleans up
KASAN_SHADOW_SCALE_SHIFT usage (which value was hardcoded and scattered
all over the code). This fixes the one place that I forgot to fix.

The change is purely aesthetical, instead of hardcoding the value for
KASAN_SHADOW_SCALE_SHIFT in arch/arm64/Makefile, an appropriate variable
is declared and used.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:33 +00:00
Ard Biesheuvel be0f272bfc arm64: ftrace: emit ftrace-mod.o contents through code
When building the arm64 kernel with both CONFIG_ARM64_MODULE_PLTS and
CONFIG_DYNAMIC_FTRACE enabled, the ftrace-mod.o object file is built
with the kernel and contains a trampoline that is linked into each
module, so that modules can be loaded far away from the kernel and
still reach the ftrace entry point in the core kernel with an ordinary
relative branch, as is emitted by the compiler instrumentation code
dynamic ftrace relies on.

In order to be able to build out of tree modules, this object file
needs to be included into the linux-headers or linux-devel packages,
which is undesirable, as it makes arm64 a special case (although a
precedent does exist for 32-bit PPC).

Given that the trampoline essentially consists of a PLT entry, let's
not bother with a source or object file for it, and simply patch it
in whenever the trampoline is being populated, using the existing
PLT support routines.

Cc: <stable@vger.kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-01 13:04:59 +00:00
Jason A. Donenfeld fb8722735f arm64: support __int128 on gcc 5+
Versions of gcc prior to gcc 5 emitted a __multi3 function call when
dealing with TI types, resulting in failures when trying to link to
libgcc, and more generally, bad performance. However, since gcc 5,
the compiler supports actually emitting fast instructions, which means
we can at long last enable this option and receive the speedups.

The gcc commit that added proper Aarch64 support is:
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=d1ae7bb994f49316f6f63e6173f2931e837a351d
This commit appears to be part of the gcc 5 release.

There are still a few instructions, __ashlti3 and __ashrti3, which
require libgcc, which is fine. Rather than linking to libgcc, we
simply provide them ourselves, since they're not that complicated.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03 15:24:21 +00:00
Nick Desaulniers fd9dde6abc arm64: prevent regressions in compressed kernel image size when upgrading to binutils 2.27
Upon upgrading to binutils 2.27, we found that our lz4 and gzip
compressed kernel images were significantly larger, resulting is 10ms
boot time regressions.

As noted by Rahul:
"aarch64 binaries uses RELA relocations, where each relocation entry
includes an addend value. This is similar to x86_64.  On x86_64, the
addend values are also stored at the relocation offset for relative
relocations. This is an optimization: in the case where code does not
need to be relocated, the loader can simply skip processing relative
relocations.  In binutils-2.25, both bfd and gold linkers did this for
x86_64, but only the gold linker did this for aarch64.  The kernel build
here is using the bfd linker, which stored zeroes at the relocation
offsets for relative relocations.  Since a set of zeroes compresses
better than a set of non-zero addend values, this behavior was resulting
in much better lz4 compression.

The bfd linker in binutils-2.27 is now storing the actual addend values
at the relocation offsets. The behavior is now consistent with what it
does for x86_64 and what gold linker does for both architectures.  The
change happened in this upstream commit:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=1f56df9d0d5ad89806c24e71f296576d82344613
Since a bunch of zeroes got replaced by non-zero addend values, we see
the side effect of lz4 compressed image being a bit bigger.

To get the old behavior from the bfd linker, "--no-apply-dynamic-relocs"
flag can be used:
$ LDFLAGS="--no-apply-dynamic-relocs" make
With this flag, the compressed image size is back to what it was with
binutils-2.25.

If the kernel is using ASLR, there aren't additional runtime costs to
--no-apply-dynamic-relocs, as the relocations will need to be applied
again anyway after the kernel is relocated to a random address.

If the kernel is not using ASLR, then presumably the current default
behavior of the linker is better. Since the static linker performed the
dynamic relocs, and the kernel is not moved to a different address at
load time, it can skip applying the relocations all over again."

Some measurements:

$ ld -v
GNU ld (binutils-2.25-f3d35cf6) 2.25.51.20141117
                    ^
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300652760 Oct 26 11:57 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 16932627 Oct 26 11:57 Image.lz4-dtb

$ ld -v
GNU ld (binutils-2.27-53dd00a1) 2.27.0.20170315
                    ^
pre patch:
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 11:43 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 18159474 Oct 26 11:43 Image.lz4-dtb

post patch:
$ ls -l vmlinux
-rwxr-x--- 1 ndesaulniers eng 300376208 Oct 26 12:06 vmlinux
$ ls -l Image.lz4-dtb
-rw-r----- 1 ndesaulniers eng 16932466 Oct 26 12:06 Image.lz4-dtb

By Siqi's measurement w/ gzip:
binutils 2.27 with this patch (with --no-apply-dynamic-relocs):
Image 41535488
Image.gz 13404067

binutils 2.27 without this patch (without --no-apply-dynamic-relocs):
Image 41535488
Image.gz 14125516

Any compression scheme should be able to get better results from the
longer runs of zeros, not just GZIP and LZ4.

10ms boot time savings isn't anything to get excited about, but users of
arm64+compression+bfd-2.27 should not have to pay a penalty for no
runtime improvement.

Reported-by: Gopinath Elanchezhian <gelanchezhian@google.com>
Reported-by: Sindhuri Pentyala <spentyala@google.com>
Reported-by: Wei Wang <wvw@google.com>
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Suggested-by: Rahul Chaudhry <rahulchaudhry@google.com>
Suggested-by: Siqi Lin <siqilin@google.com>
Suggested-by: Stephen Hines <srhines@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: added comment to Makefile]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-30 13:45:12 +00:00
Andrew Pinski 3d6a7b99e3 arm64: ensure the kernel is compiled for LP64
The kernel needs to be compiled as a LP64 binary for ARM64, even when
using a compiler that defaults to code-generation for the ILP32 ABI.
Consequently, we need to explicitly pass '-mabi=lp64' (supported on
gcc-4.9 and newer).

Signed-off-by: Andrew Pinski <Andrew.Pinski@caviumnetworks.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Reviewed-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-09-18 11:20:20 +01:00
Luc Van Oostenryck bcde519e8c arm64: pass endianness info to sparse
ARM64 depends on the macro __AARCH64EB__ being defined or not
to correctly select or define endian-specific macros, structures
or pieces of code.

This macro is predefined by the compiler but sparse knows nothing
about it and thus may pre-process files differently from what
gcc would.

Fix this by passing '-D__AARCH64EL__' or '-D__AARCH64EB__' to
sparse depending of the endianness of the kernel, like defined
by GCC.

Note: In most case it won't change anything since most arm64 use
      little-endian (but an allyesconfig would use big-endian!).

CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: linux-arm-kernel@lists.infradead.org
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-26 10:15:06 +01:00
Luc Van Oostenryck f5d284900c arm64: pass machine size to sparse
When using sparse on the arm64 tree we get many thousands of
warnings like 'constant ... is so big it is unsigned long long'
or 'shift too big (32) for type unsigned long'. This happens
because by default sparse considers the machine as 32bit and
defines the size of the types accordingly.

Fix this by passing the '-m64' flag to sparse so that
sparse can correctly define longs as being 64bit.

CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: linux-arm-kernel@lists.infradead.org
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-20 16:47:16 +01:00
Ard Biesheuvel e71a4e1beb arm64: ftrace: add support for far branches to dynamic ftrace
Currently, dynamic ftrace support in the arm64 kernel assumes that all
core kernel code is within range of ordinary branch instructions that
occur in module code, which is usually the case, but is no longer
guaranteed now that we have support for module PLTs and address space
randomization.

Since on arm64, all patching of branch instructions involves function
calls to the same entry point [ftrace_caller()], we can emit the modules
with a trampoline that has unlimited range, and patch both the trampoline
itself and the branch instruction to redirect the call via the trampoline.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: minor clarification to smp_wmb() comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-07 11:52:02 +01:00
Linus Torvalds 23ea3f62f3 Kbuild misc updates for 4.12
- Clean up builddeb script
 
 - Use full path for KBUILD_IMAGE to fix rpm-pkg build
 
 - Fix objdiff tool to ignore debug info
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Merge tag 'kbuild-misc-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull misc Kbuild updates from Masahiro Yamada:

 - clean up builddeb script

 - use full path for KBUILD_IMAGE to fix rpm-pkg build

 - fix objdiff tool to ignore debug info

* tag 'kbuild-misc-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  builddeb: fix typo
  builddeb: Update a few outdated and hardcoded strings
  deb-pkg: Remove the KBUILD_IMAGE workaround
  unicore32: Use full path in KBUILD_IMAGE definition
  sh: Use full path in KBUILD_IMAGE definition
  arc: Use full path in KBUILD_IMAGE definition
  arm: Use full path in KBUILD_IMAGE definition
  arm64: Use full path in KBUILD_IMAGE definition
  scripts: objdiff: Ignore debug info when comparing
2017-05-10 20:41:43 -07:00
Marc Zyngier d91750f12c arm64: Silence spurious kbuild warning on menuconfig
Since bbb56c2722 ("arm64: Add detection code for broken .inst support
in binutils"), running any make target that doesn't involve the cross
compiler results in a spurious warning:

$ make ARCH=arm64 menuconfig
arch/arm64/Makefile:43: Detected assembler with broken .inst; disassembly will be unreliable

while

$ make ARCH=arm64 CROSS_COMPILE=aarch64-arm-linux- menuconfig

is silent (assuming your compiler is not affected). That's because
the code that tests for the workaround is always run, irrespective
of the current configuration being available or not.

An easy fix is to make the detection conditional on CONFIG_ARM64
being defined, which is only the case when actually building
something.

Fixes: bbb56c2722 ("arm64: Add detection code for broken .inst support in binutils")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-12 09:48:03 +01:00
Michal Marek 06995804b5 arm64: Use full path in KBUILD_IMAGE definition
The KBUILD_IMAGE variable is used by the rpm and deb-pkg targets, which
expect it to point to the image file in the build directory. The
builddeb script has a workaround for architectures which only provide
the basename, but let's provide a clean interface for packaging tools.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Michal Marek <mmarek@suse.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-03-20 22:42:12 +09:00
Marc Zyngier bbb56c2722 arm64: Add detection code for broken .inst support in binutils
Binutils version up to (and including) 2.25 have a pathological
behaviour when it comes to mixing .inst directive and arithmetic
involving labels. The assembler complains about non-constant
expressions and compilation stops pretty quickly.

In order to detect this and work around it, let's add a bit of
detection code that will set the CONFIG_BROKEN_GAS_INST option
should a broken gas be detected.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-12-06 15:54:21 +00:00
Ard Biesheuvel b9dce7f1ba arm64: kernel: force ET_DYN ELF type for CONFIG_RELOCATABLE=y
GNU ld used to set the ELF file type to ET_DYN for PIE executables, which
is the same file type used for shared libraries. However, this was changed
recently, and now PIE executables are emitted as ET_EXEC instead.

The distinction is only relevant for ELF loaders, and so there is little
reason to care about the difference when building the kernel, which is
why the change has gone unnoticed until now.

However, debuggers do use the ELF binary, and expect ET_EXEC type files
to appear in memory at the exact offset described in the ELF metadata.
This means source level debugging is no longer possible when KASLR is in
effect or when executing the stub.

So add the -shared LD option when building with CONFIG_RELOCATABLE=y. This
forces the ELF file type to be set to ET_DYN (which is what you get when
building with binutils 2.24 and earlier anyway), and has no other ill
effects.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 11:37:25 +01:00
Michal Marek cfa88c7946 arm64: Set UTS_MACHINE in the Makefile
The make rpm target depends on proper UTS_MACHINE definition.  Also, use
the variable in arch/arm64/kernel/setup.c, so that it's not accidentally
removed in the future.

Reported-and-tested-by: Fabian Vogt <fvogt@suse.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31 12:31:38 +01:00
Will Deacon 6ffe9923f2 arm64: errata: Pass --fix-cortex-a53-843419 to ld if workaround enabled
Cortex-A53 erratum 843419 is worked around by the linker, although it is
a configure-time option to GCC as to whether ld is actually asked to
apply the workaround or not.

This patch ensures that we pass --fix-cortex-a53-843419 to the linker
when both CONFIG_ARM64_ERRATUM_843419=y and the linker supports the
option.

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-26 11:33:22 +01:00
Linus Torvalds 194d6ad32e arm64 fixes:
- Fix HugeTLB leak due to CoW and PTE_RDONLY mismatch
 - Avoid accessing unmapped FDT fields when checking validity
 - Correctly account for vDSO AUX entry in ARCH_DLINFO
 - Fix kallsyms with absolute expressions in linker script
 - Kill unnecessary symbol-based relocs in vmlinux
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:

 - fix HugeTLB leak due to CoW and PTE_RDONLY mismatch

 - avoid accessing unmapped FDT fields when checking validity

 - correctly account for vDSO AUX entry in ARCH_DLINFO

 - fix kallsyms with absolute expressions in linker script

 - kill unnecessary symbol-based relocs in vmlinux

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Fix copy-on-write referencing in HugeTLB
  arm64: mm: avoid fdt_check_header() before the FDT is fully mapped
  arm64: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO
  arm64: relocatable: suppress R_AARCH64_ABS64 relocations in vmlinux
  arm64: vmlinux.lds: make __rela_offset and __dynsym_offset ABSOLUTE
2016-08-06 08:58:59 -04:00
Ard Biesheuvel 08cc55b2af arm64: relocatable: suppress R_AARCH64_ABS64 relocations in vmlinux
The linker routines that we rely on to produce a relocatable PIE binary
treat it as a shared ELF object in some ways, i.e., it emits symbol based
R_AARCH64_ABS64 relocations into the final binary since doing so would be
appropriate when linking a shared library that is subject to symbol
preemption. (This means that an executable can override certain symbols
that are exported by a shared library it is linked with, and that the
shared library *must* update all its internal references as well, and point
them to the version provided by the executable.)

Symbol preemption does not occur for OS hosted PIE executables, let alone
for vmlinux, and so we would prefer to get rid of these symbol based
relocations. This would allow us to simplify the relocation routines, and
to strip the .dynsym, .dynstr and .hash sections from the binary. (Note
that these are tiny, and are placed in the .init segment, but they clutter
up the vmlinux binary.)

Note that these R_AARCH64_ABS64 relocations are only emitted for absolute
references to symbols defined in the linker script, all other relocatable
quantities are covered by anonymous R_AARCH64_RELATIVE relocations that
simply list the offsets to all 64-bit values in the binary that need to be
fixed up based on the offset between the link time and run time addresses.

Fortunately, GNU ld has a -Bsymbolic option, which is intended for shared
libraries to allow them to ignore symbol preemption, and unconditionally
bind all internal symbol references to its own definitions. So set it for
our PIE binary as well, and get rid of the asoociated sections and the
relocation code that processes them.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: fixed conflict with __dynsym_offset linker script entry]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-07-29 10:45:01 +01:00
Linus Torvalds e831101a73 arm64 updates for 4.8:
- Kexec support for arm64
 - Kprobes support
 - Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs
 - Trapping of user space cache maintenance operations and emulation in
   the kernel (CPU errata workaround)
 - Clean-up of the early page tables creation (kernel linear mapping, EFI
   run-time maps) to avoid splitting larger blocks (e.g. pmds) into
   smaller ones (e.g. ptes)
 - VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime()
 - ARCH_HAS_KCOV enabled for arm64
 - Optimise IP checksum helpers
 - SWIOTLB optimisation to only allocate/initialise the buffer if the
   available RAM is beyond the 32-bit mask
 - Properly handle the "nosmp" command line argument
 - Fix for the initialisation of the CPU debug state during early boot
 - vdso-offsets.h build dependency workaround
 - Build fix when RANDOMIZE_BASE is enabled with MODULES off
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - Kexec support for arm64

 - Kprobes support

 - Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs

 - Trapping of user space cache maintenance operations and emulation in
   the kernel (CPU errata workaround)

 - Clean-up of the early page tables creation (kernel linear mapping,
   EFI run-time maps) to avoid splitting larger blocks (e.g.  pmds) into
   smaller ones (e.g.  ptes)

 - VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime()

 - ARCH_HAS_KCOV enabled for arm64

 - Optimise IP checksum helpers

 - SWIOTLB optimisation to only allocate/initialise the buffer if the
   available RAM is beyond the 32-bit mask

 - Properly handle the "nosmp" command line argument

 - Fix for the initialisation of the CPU debug state during early boot

 - vdso-offsets.h build dependency workaround

 - Build fix when RANDOMIZE_BASE is enabled with MODULES off

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits)
  arm64: arm: Fix-up the removal of the arm64 regs_query_register_name() prototype
  arm64: Only select ARM64_MODULE_PLTS if MODULES=y
  arm64: mm: run pgtable_page_ctor() on non-swapper translation table pages
  arm64: mm: make create_mapping_late() non-allocating
  arm64: Honor nosmp kernel command line option
  arm64: Fix incorrect per-cpu usage for boot CPU
  arm64: kprobes: Add KASAN instrumentation around stack accesses
  arm64: kprobes: Cleanup jprobe_return
  arm64: kprobes: Fix overflow when saving stack
  arm64: kprobes: WARN if attempting to step with PSTATE.D=1
  arm64: debug: remove unused local_dbg_{enable, disable} macros
  arm64: debug: remove redundant spsr manipulation
  arm64: debug: unmask PSTATE.D earlier
  arm64: localise Image objcopy flags
  arm64: ptrace: remove extra define for CPSR's E bit
  kprobes: Add arm64 case in kprobe example module
  arm64: Add kernel return probes support (kretprobes)
  arm64: Add trampoline code for kretprobes
  arm64: kprobes instruction simulation support
  arm64: Treat all entry code as non-kprobe-able
  ...
2016-07-27 11:16:05 -07:00
Mark Rutland f8fa70f392 arm64: localise Image objcopy flags
We currently define OBJCOPYFLAGS in the top-level arm64 Makefile, and
thus these flags will be passed to all uses of objcopy, kernel-wide, for
which they are not explicitly overridden. The flags we set are intended
for converting vmlinux (and ELF) into Image (a raw binary), and thus the
flags chosen are problematic for some other uses which do not expect a
raw binary result, e.g. the upcoming lkdtm rodata test:

  http://www.openwall.com/lists/kernel-hardening/2016/06/08/2

This patch localises the objcopy flags such that they are only used for
the vmlinux -> Image conversion.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-19 15:30:23 +01:00
Kevin Brodsky a66649dab3 arm64: fix vdso-offsets.h dependency
arm64/kernel/{vdso,signal}.c include vdso-offsets.h, as well as any
file that includes asm/vdso.h. Therefore, vdso-offsets.h must be
generated before these files are compiled.

The current rules in arm64/kernel/Makefile do not actually enforce
this, because even though $(obj)/vdso is listed as a prerequisite for
vdso-offsets.h, this does not result in the intended effect of
building the vdso subdirectory (before all the other objects). As a
consequence, depending on the order in which the rules are followed,
vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o
are built. The current rules also impose an unnecessary dependency on
vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary
rebuilds. This is made obvious when using make -j:

  touch arch/arm64/kernel/vdso/gettimeofday.S && make -j$NCPUS arch/arm64/kernel

will sometimes result in none of arm64/kernel/*.o being
rebuilt, sometimes all of them, or even just some of them.

It is quite difficult to ensure that a header is generated before it
is used with recursive Makefiles by using normal rules.  Instead,
arch-specific generated headers are normally built in the archprepare
recipe in the arch Makefile (see for instance arch/ia64/Makefile).
Unfortunately, asm-offsets.h is included in gettimeofday.S, and must
therefore be generated before vdso-offsets.h, which is not the case if
archprepare is used. For this reason, a rule run after archprepare has
to be used.

This commit adds rules in arm64/Makefile to build vdso-offsets.h
during the prepare step, ensuring that vdso-offsets.h is generated
before building anything. It also removes the now-unnecessary
dependencies on vdso-offsets.h in arm64/kernel/Makefile. Finally, it
removes the duplication of asm-offsets.h between arm64/kernel/vdso/
and include/generated/ and makes include/generated/vdso-offsets.h a
target in arm64/kernel/vdso/Makefile.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Michal Marek <mmarek@suse.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-11 17:10:11 +01:00
Masahiro Yamada 9ca4e58c20 arm64: fix boot image dependencies to not generate invalid images
I fixed boot image dependencies for arch/arm in commit 3939f33450
("ARM: 8418/1: add boot image dependencies to not generate invalid
images").

I see a similar problem for arch/arm64; "make -jN Image Image.gz"
would sometimes end up generating bad images where N > 1.

Fix the dependency in arch/arm64/Makefile to avoid the race
between "make Image" and "make Image.*".

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-21 20:10:18 +01:00
Mark Rutland aed7eb8367 arm64: fix alignment when RANDOMIZE_TEXT_OFFSET is enabled
With ARM64_64K_PAGES and RANDOMIZE_TEXT_OFFSET enabled, we hit the
following issue on the boot:

kernel BUG at arch/arm64/mm/mmu.c:480!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.6.0 #310
Hardware name: ARM Juno development board (r2) (DT)
task: ffff000008d58a80 ti: ffff000008d30000 task.ti: ffff000008d30000
PC is at map_kernel_segment+0x44/0xb0
LR is at paging_init+0x84/0x5b0
pc : [<ffff000008c450b4>] lr : [<ffff000008c451a4>] pstate: 600002c5

Call trace:
[<ffff000008c450b4>] map_kernel_segment+0x44/0xb0
[<ffff000008c451a4>] paging_init+0x84/0x5b0
[<ffff000008c42728>] setup_arch+0x198/0x534
[<ffff000008c40848>] start_kernel+0x70/0x388
[<ffff000008c401bc>] __primary_switched+0x30/0x74

Commit 7eb90f2ff7 ("arm64: cover the .head.text section in the .text
segment mapping") removed the alignment between the .head.text and .text
sections, and used the _text rather than the _stext interval for mapping
the .text segment.

Prior to this commit _stext was always section aligned and didn't cause
any issue even when RANDOMIZE_TEXT_OFFSET was enabled. Since that
alignment has been removed and _text is used to map the .text segment,
we need ensure _text is always page aligned when RANDOMIZE_TEXT_OFFSET
is enabled.

This patch adds logic to TEXT_OFFSET fuzzing to ensure that the offset
is always aligned to the kernel page size. To ensure this, we rely on
the PAGE_SHIFT being available via Kconfig.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Fixes: 7eb90f2ff7 ("arm64: cover the .head.text section in the .text segment mapping")
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-03 10:57:18 +01:00
Linus Torvalds 588ab3f9af arm64 updates for 4.6:
- Initial page table creation reworked to avoid breaking large block
   mappings (huge pages) into smaller ones. The ARM architecture requires
   break-before-make in such cases to avoid TLB conflicts but that's not
   always possible on live page tables
 
 - Kernel virtual memory layout: the kernel image is no longer linked to
   the bottom of the linear mapping (PAGE_OFFSET) but at the bottom of
   the vmalloc space, allowing the kernel to be loaded (nearly) anywhere
   in physical RAM
 
 - Kernel ASLR: position independent kernel Image and modules being
   randomly mapped in the vmalloc space with the randomness is provided
   by UEFI (efi_get_random_bytes() patches merged via the arm64 tree,
   acked by Matt Fleming)
 
 - Implement relative exception tables for arm64, required by KASLR
   (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c but
   actual x86 conversion to deferred to 4.7 because of the merge
   dependencies)
 
 - Support for the User Access Override feature of ARMv8.2: this allows
   uaccess functions (get_user etc.) to be implemented using LDTR/STTR
   instructions. Such instructions, when run by the kernel, perform
   unprivileged accesses adding an extra level of protection. The
   set_fs() macro is used to "upgrade" such instruction to privileged
   accesses via the UAO bit
 
 - Half-precision floating point support (part of ARMv8.2)
 
 - Optimisations for CPUs with or without a hardware prefetcher (using
   run-time code patching)
 
 - copy_page performance improvement to deal with 128 bytes at a time
 
 - Sanity checks on the CPU capabilities (via CPUID) to prevent
   incompatible secondary CPUs from being brought up (e.g. weird
   big.LITTLE configurations)
 
 - valid_user_regs() reworked for better sanity check of the sigcontext
   information (restored pstate information)
 
 - ACPI parking protocol implementation
 
 - CONFIG_DEBUG_RODATA enabled by default
 
 - VDSO code marked as read-only
 
 - DEBUG_PAGEALLOC support
 
 - ARCH_HAS_UBSAN_SANITIZE_ALL enabled
 
 - Erratum workaround Cavium ThunderX SoC
 
 - set_pte_at() fix for PROT_NONE mappings
 
 - Code clean-ups
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "Here are the main arm64 updates for 4.6.  There are some relatively
  intrusive changes to support KASLR, the reworking of the kernel
  virtual memory layout and initial page table creation.

  Summary:

   - Initial page table creation reworked to avoid breaking large block
     mappings (huge pages) into smaller ones.  The ARM architecture
     requires break-before-make in such cases to avoid TLB conflicts but
     that's not always possible on live page tables

   - Kernel virtual memory layout: the kernel image is no longer linked
     to the bottom of the linear mapping (PAGE_OFFSET) but at the bottom
     of the vmalloc space, allowing the kernel to be loaded (nearly)
     anywhere in physical RAM

   - Kernel ASLR: position independent kernel Image and modules being
     randomly mapped in the vmalloc space with the randomness is
     provided by UEFI (efi_get_random_bytes() patches merged via the
     arm64 tree, acked by Matt Fleming)

   - Implement relative exception tables for arm64, required by KASLR
     (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c
     but actual x86 conversion to deferred to 4.7 because of the merge
     dependencies)

   - Support for the User Access Override feature of ARMv8.2: this
     allows uaccess functions (get_user etc.) to be implemented using
     LDTR/STTR instructions.  Such instructions, when run by the kernel,
     perform unprivileged accesses adding an extra level of protection.
     The set_fs() macro is used to "upgrade" such instruction to
     privileged accesses via the UAO bit

   - Half-precision floating point support (part of ARMv8.2)

   - Optimisations for CPUs with or without a hardware prefetcher (using
     run-time code patching)

   - copy_page performance improvement to deal with 128 bytes at a time

   - Sanity checks on the CPU capabilities (via CPUID) to prevent
     incompatible secondary CPUs from being brought up (e.g.  weird
     big.LITTLE configurations)

   - valid_user_regs() reworked for better sanity check of the
     sigcontext information (restored pstate information)

   - ACPI parking protocol implementation

   - CONFIG_DEBUG_RODATA enabled by default

   - VDSO code marked as read-only

   - DEBUG_PAGEALLOC support

   - ARCH_HAS_UBSAN_SANITIZE_ALL enabled

   - Erratum workaround Cavium ThunderX SoC

   - set_pte_at() fix for PROT_NONE mappings

   - Code clean-ups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (99 commits)
  arm64: kasan: Fix zero shadow mapping overriding kernel image shadow
  arm64: kasan: Use actual memory node when populating the kernel image shadow
  arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission
  arm64: Fix misspellings in comments.
  arm64: efi: add missing frame pointer assignment
  arm64: make mrs_s prefixing implicit in read_cpuid
  arm64: enable CONFIG_DEBUG_RODATA by default
  arm64: Rework valid_user_regs
  arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly
  arm64: KVM: Move kvm_call_hyp back to its original localtion
  arm64: mm: treat memstart_addr as a signed quantity
  arm64: mm: list kernel sections in order
  arm64: lse: deal with clobbered IP registers after branch via PLT
  arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDR
  arm64: kconfig: add submenu for 8.2 architectural features
  arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot
  arm64: Add support for Half precision floating point
  arm64: Remove fixmap include fragility
  arm64: Add workaround for Cavium erratum 27456
  arm64: mm: Mark .rodata as RO
  ...
2016-03-17 20:03:47 -07:00
Ard Biesheuvel 1e48ef7fcc arm64: add support for building vmlinux as a relocatable PIE binary
This implements CONFIG_RELOCATABLE, which links the final vmlinux
image with a dynamic relocation section, allowing the early boot code
to perform a relocation to a different virtual address at runtime.

This is a prerequisite for KASLR (CONFIG_RANDOMIZE_BASE).

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:27 +00:00
Ard Biesheuvel fd045f6cd9 arm64: add support for module PLTs
This adds support for emitting PLTs at module load time for relative
branches that are out of range. This is a prerequisite for KASLR, which
may place the kernel and the modules anywhere in the vmalloc area,
making it more likely that branch target offsets exceed the maximum
range of +/- 128 MB.

In this version, I removed the distinction between relocations against
.init executable sections and ordinary executable sections. The reason
is that it is hardly worth the trouble, given that .init.text usually
does not contain that many far branches, and this version now only
reserves PLT entry space for jump and call relocations against undefined
symbols (since symbols defined in the same module can be assumed to be
within +/- 128 MB)

For example, the mac80211.ko module (which is fairly sizable at ~400 KB)
built with -mcmodel=large gives the following relocation counts:

                    relocs    branches   unique     !local
  .text              3925       3347       518        219
  .init.text           11          8         7          1
  .exit.text            4          4         4          1
  .text.unlikely       81         67        36         17

('unique' means branches to unique type/symbol/addend combos, of which
!local is the subset referring to undefined symbols)

IOW, we are only emitting a single PLT entry for the .init sections, and
we are better off just adding it to the core PLT section instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 14:57:24 +00:00
Masahiro Yamada 8684fa3e7a arm64: kbuild: make "make install" not depend on vmlinux
For the same reason as commit 19514fc665 ("arm, kbuild: make "make
install" not depend on vmlinux"), the install targets should never
trigger the rebuild of the kernel.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-19 10:33:35 +00:00
dann frazier 67dfa1751c arm64: errata: Add -mpc-relative-literal-loads to build flags
GCC6 (and Linaro's 2015.12 snapshot of GCC5) has a new default that uses
adrp/ldr or adrp/add to address literal pools. When CONFIG_ARM64_ERRATUM_843419
is enabled, modules built with this toolchain fail to load:

  module libahci: unsupported RELA relocation: 275

This patch fixes the problem by passing '-mpc-relative-literal-loads'
to the compiler.

Cc: stable@vger.kernel.org
Fixes: df057cc7b4 ("arm64: errata: add module build workaround for erratum #843419")
BugLink: http://bugs.launchpad.net/bugs/1533009
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Suggested-by: Christophe Lyon <christophe.lyon@linaro.org>
Signed-off-by: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-26 11:17:23 +00:00
William Cohen 728dabd6d1 Eliminate the .eh_frame sections from the aarch64 vmlinux and kernel modules
By default the aarch64 gcc generates .eh_frame sections.  Unlike
.debug_frame sections, the .eh_frame sections are loaded into memory
when the associated code is loaded.  On an example kernel being built
with this default the .eh_frame section in vmlinux used an extra 1.7MB
of memory.  The x86 disables the creation of the .eh_frame section.
The aarch64 should probably do the same to save some memory.

Signed-off-by: William Cohen <wcohen@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-26 11:14:13 +00:00
Linus Torvalds 2dc10ad81f arm64 updates for 4.4:
- "genirq: Introduce generic irq migration for cpu hotunplugged" patch
   merged from tip/irq/for-arm to allow the arm64-specific part to be
   upstreamed via the arm64 tree
 
 - CPU feature detection reworked to cope with heterogeneous systems
   where CPUs may not have exactly the same features. The features
   reported by the kernel via internal data structures or ELF_HWCAP are
   delayed until all the CPUs are up (and before user space starts)
 
 - Support for 16KB pages, with the additional bonus of a 36-bit VA
   space, though the latter only depending on EXPERT
 
 - Implement native {relaxed, acquire, release} atomics for arm64
 
 - New ASID allocation algorithm which avoids IPI on roll-over, together
   with TLB invalidation optimisations (using local vs global where
   feasible)
 
 - KASan support for arm64
 
 - EFI_STUB clean-up and isolation for the kernel proper (required by
   KASan)
 
 - copy_{to,from,in}_user optimisations (sharing the memcpy template)
 
 - perf: moving arm64 to the arm32/64 shared PMU framework
 
 - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware
 
 - Support for the contiguous PTE hint on kernel mapping (16 consecutive
   entries may be able to use a single TLB entry)
 
 - Generic CONFIG_HZ now used on arm64
 
 - defconfig updates
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - "genirq: Introduce generic irq migration for cpu hotunplugged" patch
   merged from tip/irq/for-arm to allow the arm64-specific part to be
   upstreamed via the arm64 tree

 - CPU feature detection reworked to cope with heterogeneous systems
   where CPUs may not have exactly the same features.  The features
   reported by the kernel via internal data structures or ELF_HWCAP are
   delayed until all the CPUs are up (and before user space starts)

 - Support for 16KB pages, with the additional bonus of a 36-bit VA
   space, though the latter only depending on EXPERT

 - Implement native {relaxed, acquire, release} atomics for arm64

 - New ASID allocation algorithm which avoids IPI on roll-over, together
   with TLB invalidation optimisations (using local vs global where
   feasible)

 - KASan support for arm64

 - EFI_STUB clean-up and isolation for the kernel proper (required by
   KASan)

 - copy_{to,from,in}_user optimisations (sharing the memcpy template)

 - perf: moving arm64 to the arm32/64 shared PMU framework

 - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware

 - Support for the contiguous PTE hint on kernel mapping (16 consecutive
   entries may be able to use a single TLB entry)

 - Generic CONFIG_HZ now used on arm64

 - defconfig updates

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits)
  arm64/efi: fix libstub build under CONFIG_MODVERSIONS
  ARM64: Enable multi-core scheduler support by default
  arm64/efi: move arm64 specific stub C code to libstub
  arm64: page-align sections for DEBUG_RODATA
  arm64: Fix build with CONFIG_ZONE_DMA=n
  arm64: Fix compat register mappings
  arm64: Increase the max granular size
  arm64: remove bogus TASK_SIZE_64 check
  arm64: make Timer Interrupt Frequency selectable
  arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED
  arm64: cachetype: fix definitions of ICACHEF_* flags
  arm64: cpufeature: declare enable_cpu_capabilities as static
  genirq: Make the cpuhotplug migration code less noisy
  arm64: Constify hwcap name string arrays
  arm64/kvm: Make use of the system wide safe values
  arm64/debug: Make use of the system wide safe value
  arm64: Move FP/ASIMD hwcap handling to common code
  arm64/HWCAP: Use system wide safe values
  arm64/capabilities: Make use of system wide safe value
  arm64: Delay cpu feature capability checks
  ...
2015-11-04 14:47:13 -08:00
Andrey Ryabinin 39d114ddc6 arm64: add KASAN support
This patch adds arch specific code for kernel address sanitizer
(see Documentation/kasan.txt).

1/8 of kernel addresses reserved for shadow memory. There was no
big enough hole for this, so virtual addresses for shadow were
stolen from vmalloc area.

At early boot stage the whole shadow region populated with just
one physical page (kasan_zero_page). Later, this page reused
as readonly zero shadow for some memory that KASan currently
don't track (vmalloc).
After mapping the physical memory, pages for shadow memory are
allocated and mapped.

Functions like memset/memmove/memcpy do a lot of memory accesses.
If bad pointer passed to one of these function it is important
to catch this. Compiler's instrumentation cannot do this since
these functions are written in assembly.
KASan replaces memory functions with manually instrumented variants.
Original functions declared as weak symbols so strong definitions
in mm/kasan/kasan.c could replace them. Original functions have aliases
with '__' prefix in name, so we could call non-instrumented variant
if needed.
Some files built without kasan instrumentation (e.g. mm/slub.c).
Original mem* function replaced (via #define) with prefixed variants
to disable memory access checks for such files.

Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-12 17:46:36 +01:00
Will Deacon b6dd8e0719 arm64: errata: use KBUILD_CFLAGS_MODULE for erratum #843419
Commit df057cc7b4 ("arm64: errata: add module build workaround for
erratum #843419") sets CFLAGS_MODULE to ensure that the large memory
model is used by the compiler when building kernel modules.

However, CFLAGS_MODULE is an environment variable and intended to be
overridden on the command line, which appears to be the case with the
Ubuntu kernel packaging system, so use KBUILD_CFLAGS_MODULE instead.

Cc: <stable@vger.kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Fixes: df057cc7b4 ("arm64: errata: add module build workaround for erratum #843419")
Reported-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-10-12 17:40:12 +01:00
Will Deacon df057cc7b4 arm64: errata: add module build workaround for erratum #843419
Cortex-A53 processors <= r0p4 are affected by erratum #843419 which can
lead to a memory access using an incorrect address in certain sequences
headed by an ADRP instruction.

There is a linker fix to generate veneers for ADRP instructions, but
this doesn't work for kernel modules which are built as unlinked ELF
objects.

This patch adds a new config option for the erratum which, when enabled,
builds kernel modules with the mcmodel=large flag. This uses absolute
addressing for all kernel symbols, thereby removing the use of ADRP as
a PC-relative form of addressing. The ADRP relocs are removed from the
module loader so that we fail to load any potentially affected modules.

Cc: <stable@vger.kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-09-17 11:57:03 +01:00
Will Deacon c09d6a04d1 arm64: atomics: patch in lse instructions when supported by the CPU
On CPUs which support the LSE atomic instructions introduced in ARMv8.1,
it makes sense to use them in preference to ll/sc sequences.

This patch introduces runtime patching of atomic_t and atomic64_t
routines so that the call-site for the out-of-line ll/sc sequences is
patched with an LSE atomic instruction when we detect that
the CPU supports it.

If binutils is not recent enough to assemble the LSE instructions, then
the ll/sc sequences are inlined as though CONFIG_ARM64_LSE_ATOMICS=n.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 15:28:50 +01:00
Olof Johansson 0723c05fb7 arm64: enable more compressed Image formats
Plumb up Makefile arguments for the already supported formats in the kbuild
system: lz4, bzip2, lzma, and lzo.

Note that just as with Image.gz, these images are not self-decompressing and
the booting firmware still needs to handle decompression before launching the
kernel image.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:39 +01:00
Steve Capper ad08fd494b arm64: Adjust EFI libstub object include logic
Commit f4f75ad5 ("efi: efistub: Convert into static library")
introduced a static library for EFI stub, libstub.

The EFI libstub directory is referenced by the kernel build system via
a obj subdirectory rule in:
drivers/firmware/efi/Makefile

Unfortunately, arm64 also references the EFI libstub via:
libs-$(CONFIG_EFI_STUB) += drivers/firmware/efi/libstub/

If we're unlucky, the kernel build system can enter libstub via two
simultaneous threads resulting in build failures such as:

fixdep: error opening depfile: drivers/firmware/efi/libstub/.efi-stub-helper.o.d: No such file or directory
scripts/Makefile.build:257: recipe for target 'drivers/firmware/efi/libstub/efi-stub-helper.o' failed
make[1]: *** [drivers/firmware/efi/libstub/efi-stub-helper.o] Error 2
Makefile:939: recipe for target 'drivers/firmware/efi/libstub' failed
make: *** [drivers/firmware/efi/libstub] Error 2
make: *** Waiting for unfinished jobs....

This patch adjusts the arm64 Makefile to reference the compiled library
explicitly (as is currently done in x86), rather than the directory.

Fixes: f4f75ad5 efi: efistub: Convert into static library
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-17 16:59:47 +00:00
Linus Torvalds 6b00f7efb5 arm64 updates for 3.20:
- reimplementation of the virtual remapping of UEFI Runtime Services in
   a way that is stable across kexec
 - emulation of the "setend" instruction for 32-bit tasks (user
   endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set
   accordingly)
 - compat_sys_call_table implemented in C (from asm) and made it a
   constant array together with sys_call_table
 - export CPU cache information via /sys (like other architectures)
 - DMA API implementation clean-up in preparation for IOMMU support
 - macros clean-up for KVM
 - dropped some unnecessary cache+tlb maintenance
 - CONFIG_ARM64_CPU_SUSPEND clean-up
 - defconfig update (CPU_IDLE)
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "arm64 updates for 3.20:

   - reimplementation of the virtual remapping of UEFI Runtime Services
     in a way that is stable across kexec
   - emulation of the "setend" instruction for 32-bit tasks (user
     endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set
     accordingly)
   - compat_sys_call_table implemented in C (from asm) and made it a
     constant array together with sys_call_table
   - export CPU cache information via /sys (like other architectures)
   - DMA API implementation clean-up in preparation for IOMMU support
   - macros clean-up for KVM
   - dropped some unnecessary cache+tlb maintenance
   - CONFIG_ARM64_CPU_SUSPEND clean-up
   - defconfig update (CPU_IDLE)

  The EFI changes going via the arm64 tree have been acked by Matt
  Fleming.  There is also a patch adding sys_*stat64 prototypes to
  include/linux/syscalls.h, acked by Andrew Morton"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (47 commits)
  arm64: compat: Remove incorrect comment in compat_siginfo
  arm64: Fix section mismatch on alloc_init_p[mu]d()
  arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros
  arm64: mm: use *_sect to check for section maps
  arm64: drop unnecessary cache+tlb maintenance
  arm64:mm: free the useless initial page table
  arm64: Enable CPU_IDLE in defconfig
  arm64: kernel: remove ARM64_CPU_SUSPEND config option
  arm64: make sys_call_table const
  arm64: Remove asm/syscalls.h
  arm64: Implement the compat_sys_call_table in C
  syscalls: Declare sys_*stat64 prototypes if __ARCH_WANT_(COMPAT_)STAT64
  compat: Declare compat_sys_sigpending and compat_sys_sigprocmask prototypes
  arm64: uapi: expose our struct ucontext to the uapi headers
  smp, ARM64: Kill SMP single function call interrupt
  arm64: Emulate SETEND for AArch32 tasks
  arm64: Consolidate hotplug notifier for instruction emulation
  arm64: Track system support for mixed endian EL0
  arm64: implement generic IOMMU configuration
  arm64: Combine coherent and non-coherent swiotlb dma_ops
  ...
2015-02-11 18:03:54 -08:00
Jungseok Lee c7c52e4829 arm64: Add dtb files to archclean rule
As dts files have been reorganised under vendor subdirs, dtb files
cannot be removed with "make distclean" now. Thus, this patch moves
dtb files under archclean rule and removes unnecessary entries.

Cc: Robert Richter <rrichter@cavium.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-01-20 11:30:08 +00:00
Kevin Hao d67703a8a6 arm64: kill off the libgcc dependency
The arm64 kernel builds fine without the libgcc. Actually it should not
be used at all in the kernel. The following are the reasons indicated
by Russell King:

  Although libgcc is part of the compiler, libgcc is built with the
  expectation that it will be running in userland - it expects to link
  to a libc.  That's why you can't build libgcc without having the glibc
  headers around.

  [...]

  Meanwhile, having the kernel build the compiler support functions that
  it needs ensures that (a) we know what compiler support functions are
  being used, (b) we know the implementation of those support functions
  are sane for use in the kernel, (c) we can build them with appropriate
  compiler flags for best performance, and (d) we remove an unnecessary
  dependency on the build toolchain.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-15 15:52:21 +00:00
Robert Richter d38726c485 dts, arm/arm64: Remove dtbs build rules in sub-makes
Add dtb files to build targets and let kbuild handle them. Thus,
special dtbs rules can be removed. This eases Makefiles and the
implementation of the support of vendor dtb subdirectories.

Signed-off-by: Robert Richter <rrichter@cavium.com>
2014-10-21 18:06:58 +02:00
Robert Richter 9fb5e53722 dts, kbuild: Factor out dtbs install rules to Makefile.dtbinst
Move dtbs install rules to Makefile.dtbinst. This change is needed to
implement support for dts vendor subdirs. The change makes Makefiles
easier and smaller as no longer the dtbs_install rule needs to be
defined. Another advantage is that install goals are not encoded in
targets anymore (%.dtb_dtbinst_).

Signed-off-by: Robert Richter <rrichter@cavium.com>
2014-10-21 18:06:58 +02:00
Robert Richter 862f464a54 dts, arm64: Add dtbs_install make target
This adds the dtbs_install make target to arm64. The target has been
introduced already to arch/arm with the following commit:

 f4d4ffc03e kbuild: dtbs_install: new make target

Implementation for arm64 is the same as for arm.

With 'dtbs_install' all config enabled dtb files are installed to
either the INSTALL_DTBS_PATH directory or the default location:

 $INSTALL_PATH/dtbs/$KERNELRELEASE

Signed-off-by: Robert Richter <rrichter@cavium.com>
2014-10-21 18:06:57 +02:00
Linus Torvalds f33a3faa25 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild changes from Michal Marek:
 - fix for handling dependencies of *-objs targets by Masahiro Yamada
 - lots of cleanups in the kbuild machinery, also by Masahiro
 - fixes for the kconfig build to use an UTF-8 capable ncurses library
   if possible and to build on not-so-standard installs
 - some more minor fixes

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Do not reference *-n variables in the Makefile
  kbuild: simplify build, clean, modbuiltin shorthands
  kbuild: arm: Do not define "comma" twice
  kbuild: remove obj-n and lib-n handling
  kbuild: remove unnecessary variable initializaions
  kbuild: remove unnecessary "obj- := dummy.o" trick
  kbuild: handle C=... and M=... after entering into build directory
  kbuild: use $(Q) for sub-make target
  kbuild: fake the "Entering directory ..." message more simply
  kconfig/lxdialog: get ncurses CFLAGS with pkg-config
  kconfig: nconfig: fix multi-byte UTF handling
  kconfig: lxdialog: fix spelling
  kbuild: Make scripts executable
  kbuild: remove redundant clean-files from scripts/kconfig/Makefile
  kbuild: refactor script/kconfig/Makefile
  kbuild: handle the dependency of multi-objs hostprogs appropriately
  kbuild: handle multi-objs dependency appropriately
2014-10-14 09:22:26 +02:00
Masahiro Yamada 226422d08c kbuild: arm: Do not define "comma" twice
The definition of "comma" exists in scripts/Kbuild.include.
We should not double it.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-10-02 15:09:47 +02:00
Zi Shen Lim e54bcde3d6 arm64: eBPF JIT compiler
The JIT compiler emits A64 instructions. It supports eBPF only.
Legacy BPF is supported thanks to conversion by BPF core.

JIT is enabled in the same way as for other architectures:

	echo 1 > /proc/sys/net/core/bpf_jit_enable

Or for additional compiler output:

	echo 2 > /proc/sys/net/core/bpf_jit_enable

See Documentation/networking/filter.txt for more information.

The implementation passes all 57 tests in lib/test_bpf.c
on ARMv8 Foundation Model :) Also tested by Will on Juno platform.

Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-09-08 14:39:21 +01:00
Ard Biesheuvel 4190312beb arm64: align randomized TEXT_OFFSET on 4 kB boundary
When booting via UEFI, the kernel Image is loaded at a 4 kB boundary and
the embedded EFI stub is executed in place. The EFI stub relocates the
Image to reside TEXT_OFFSET bytes above a 2 MB boundary, and jumps into
the kernel proper.

In AArch64, PC relative symbol references are emitted using adrp/add or
adrp/ldr pairs, where the offset into a 4 kB page is resolved using a
separate :lo12: relocation. This implicitly assumes that the code will
always be executed at the same relative offset with respect to a 4 kB
boundary, or the references will point to the wrong address.

This means we should link the kernel at a 4 kB aligned base address in
order to remain compatible with the base address the UEFI loader uses
when doing the initial load of Image. So update the code that generates
TEXT_OFFSET to choose a multiple of 4 kB.

At the same time, update the code so it chooses from the interval [0..2MB)
as the author originally intended.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-08-19 19:26:09 +01:00
Linus Torvalds 76f09aa464 Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI changes from Ingo Molnar:
 "Main changes in this cycle are:

   - arm64 efi stub fixes, preservation of FP/SIMD registers across
     firmware calls, and conversion of the EFI stub code into a static
     library - Ard Biesheuvel

   - Xen EFI support - Daniel Kiper

   - Support for autoloading the efivars driver - Lee, Chun-Yi

   - Use the PE/COFF headers in the x86 EFI boot stub to request that
     the stub be loaded with CONFIG_PHYSICAL_ALIGN alignment - Michael
     Brown

   - Consolidate all the x86 EFI quirks into one file - Saurabh Tangri

   - Additional error logging in x86 EFI boot stub - Ulf Winkelvos

   - Support loading initrd above 4G in EFI boot stub - Yinghai Lu

   - EFI reboot patches for ACPI hardware reduced platforms"

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  efi/arm64: Handle missing virtual mapping for UEFI System Table
  arch/x86/xen: Silence compiler warnings
  xen: Silence compiler warnings
  x86/efi: Request desired alignment via the PE/COFF headers
  x86/efi: Add better error logging to EFI boot stub
  efi: Autoload efivars
  efi: Update stale locking comment for struct efivars
  arch/x86: Remove efi_set_rtc_mmss()
  arch/x86: Replace plain strings with constants
  xen: Put EFI machinery in place
  xen: Define EFI related stuff
  arch/x86: Remove redundant set_bit(EFI_MEMMAP) call
  arch/x86: Remove redundant set_bit(EFI_SYSTEM_TABLES) call
  efi: Introduce EFI_PARAVIRT flag
  arch/x86: Do not access EFI memory map if it is not available
  efi: Use early_mem*() instead of early_io*()
  arch/ia64: Define early_memunmap()
  x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag
  efi/reboot: Allow powering off machines using EFI
  efi/reboot: Add generic wrapper around EfiResetSystem()
  ...
2014-08-04 17:13:50 -07:00