Commit Graph

59 Commits

Author SHA1 Message Date
Linus Torvalds 5ad18b2e60 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...
2019-07-08 21:48:15 -07:00
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Eric W. Biederman 2e1661d267 signal: Remove the task parameter from force_sig_fault
As synchronous exceptions really only make sense against the current
task (otherwise how are you synchronous) remove the task parameter
from from force_sig_fault to make it explicit that is what is going
on.

The two known exceptions that deliver a synchronous exception to a
stopped ptraced task have already been changed to
force_sig_fault_to_task.

The callers have been changed with the following emacs regular expression
(with obvious variations on the architectures that take more arguments)
to avoid typos:

force_sig_fault[(]\([^,]+\)[,]\([^,]+\)[,]\([^,]+\)[,]\W+current[)]
->
force_sig_fault(\1,\2,\3)

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-29 09:31:43 -05:00
Sakari Ailus d75f773c86 treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
%pF and %pf are functionally equivalent to %pS and %ps conversion
specifiers. The former are deprecated, therefore switch the current users
to use the preferred variant.

The changes have been produced by the following command:

	git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \
	while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done

And verifying the result.

Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: xen-devel@lists.xenproject.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: drbd-dev@lists.linbit.com
Cc: linux-block@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Cc: linux-pci@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-btrfs@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-mm@kvack.org
Cc: ceph-devel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: David Sterba <dsterba@suse.com> (for btrfs)
Acked-by: Mike Rapoport <rppt@linux.ibm.com> (for mm/memblock.c)
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (for drivers/pci)
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-09 14:19:06 +02:00
Eric W. Biederman 3ee6a44987 signal/arm: Use force_sig_fault where appropriate
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-09-27 21:57:39 +02:00
Eric W. Biederman 3eb0f5193b signal: Ensure every siginfo we send has all bits initialized
Call clear_siginfo to ensure every stack allocated siginfo is properly
initialized before being passed to the signal sending functions.

Note: It is not safe to depend on C initializers to initialize struct
siginfo on the stack because C is allowed to skip holes when
initializing a structure.

The initialization of struct siginfo in tracehook_report_syscall_exit
was moved from the helper user_single_step_siginfo into
tracehook_report_syscall_exit itself, to make it clear that the local
variable siginfo gets fully initialized.

In a few cases the scope of struct siginfo has been reduced to make it
clear that siginfo siginfo is not used on other paths in the function
in which it is declared.

Instances of using memset to initialize siginfo have been replaced
with calls clear_siginfo for clarity.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:40:51 -05:00
Ingo Molnar b17b01533b sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/debug.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
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>
2017-03-02 08:42:34 +01:00
Ingo Molnar 3f07c01441 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
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>
2017-03-02 08:42:29 +01:00
Andrew Morton 0ab32b6f1b uaccess: reimplement probe_kernel_address() using probe_kernel_read()
probe_kernel_address() is basically the same as the (later added)
probe_kernel_read().

The return value on EFAULT is a bit different: probe_kernel_address()
returns number-of-bytes-not-copied whereas probe_kernel_read() returns
-EFAULT.  All callers have been checked, none cared.

probe_kernel_read() can be overridden by the architecture whereas
probe_kernel_address() cannot.  parisc, blackfin and um do this, to insert
additional checking.  Hence this patch possibly fixes obscure bugs,
although there are only two probe_kernel_address() callsites outside
arch/.

My first attempt involved removing probe_kernel_address() entirely and
converting all callsites to use probe_kernel_read() directly, but that got
tiresome.

This patch shrinks mm/slab_common.o by 218 bytes.  For a single
probe_kernel_address() callsite.

Cc: Steven Miao <realmz6@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Russell King 274e91b81e ARM: alignment: fix alignment handling for uaccess changes
Jonathan Liu reports that the recent addition of CPU_SW_DOMAIN_PAN
causes wpa_supplicant to die due to the following kernel oops:

Unhandled fault: page domain fault (0x81b) at 0x001017a2
pgd = ee1b8000
[001017a2] *pgd=6ebee831, *pte=6c35475f, *ppte=6c354c7f
Internal error: : 81b [#1] SMP ARM
Modules linked in: rt2800usb rt2x00usb rt2800librt2x00lib crc_ccitt mac80211
CPU: 1 PID: 202 Comm: wpa_supplicant Not tainted 4.3.0-rc2 #1
Hardware name: Allwinner sun7i (A20) Family
task: ec872f80 ti: ee364000 task.ti: ee364000
PC is at do_alignment_ldmstm+0x1d4/0x238
LR is at 0x0
pc : [<c001d1d8>]    lr : [<00000000>]    psr: 600c0113
sp : ee365e18  ip : 00000000  fp : 00000002
r10: 001017a2  r9 : 00000002  r8 : 001017aa
r7 : ee365fb0  r6 : e8820018  r5 : 001017a2  r4 : 00000003
r3 : d49e30e0  r2 : 00000000  r1 : ee365fbc  r0 : 00000000
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none[   34.393106] Control: 10c5387d  Table: 6e1b806a  DAC: 00000051
Process wpa_supplicant (pid: 202, stack limit = 0xee364210)
Stack: (0xee365e18 to 0xee366000)
...
[<c001d1d8>] (do_alignment_ldmstm) from [<c001d510>] (do_alignment+0x1f0/0x904)
[<c001d510>] (do_alignment) from [<c00092a0>] (do_DataAbort+0x38/0xb4)
[<c00092a0>] (do_DataAbort) from [<c0013d7c>] (__dabt_usr+0x3c/0x40)
Exception stack(0xee365fb0 to 0xee365ff8)
5fa0:                                     00000000 56c728c0 001017a2 d49e30e0
5fc0: 775448d2 597d4e74 00200800 7a9e1625 00802001 00000021 b6deec84 00000100
5fe0: 08020200 be9f4f20 0c0b0d0a b6d9b3e0 600c0010 ffffffff
Code: e1a0a005 e1a0000c 1affffe8 e5913000 (e4ea3001)
---[ end trace 0acd3882fcfdf9dd ]---

This is caused by the alignment handler not being fixed up for the
uaccess changes, and userspace issuing an unaligned LDM instruction.
So, fix the problem by adding the necessary fixups.

Reported-by: Jonathan Liu <net147@gmail.com>
Tested-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-09-24 11:07:00 +01:00
Ard Biesheuvel c4a84ae39b ARM: 8322/1: keep .text and .fixup regions closer together
This moves all fixup snippets to the .text.fixup section, which is
a special section that gets emitted along with the .text section
for each input object file, i.e., the snippets are kept much closer
to the code they refer to, which helps prevent linker failure on
large kernels.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-29 23:11:56 +01:00
Russell King 4ed89f2228 ARM: convert printk(KERN_* to pr_*
Convert many (but not all) printk(KERN_* to pr_* to simplify the code.
We take the opportunity to join some printk lines together so we don't
split the message across several lines, and we also add a few levels
to some messages which were previously missing them.

Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-11-21 15:24:50 +00:00
Robin Murphy 5ca918e5e3 ARM: 8165/1: alignment: don't break misaligned NEON load/store
The alignment fixup incorrectly decodes faulting ARM VLDn/VSTn
instructions (where the optional alignment hint is given but incorrect)
as LDR/STR, leading to register corruption. Detect these and correctly
treat them as unhandled, so that userspace gets the fault it expects.

Reported-by: Simon Hosie <simon.hosie@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-09-25 15:32:57 +01:00
Russell King 1e7e321185 ARM: alignment: save last kernel aligned fault location
Save and report (via the procfs file) the last kernel unaligned fault
location.  This allows us to trivially inspect where the last fault
happened for cases which we don't expect to occur.

Since we expect the kernel to generate misalignment faults (due to
the networking layer), even when warnings are enabled, we don't log
them for the kernel.

Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18 12:29:06 +01:00
Russell King 0aeb3408ca ARM: remove global cr_no_alignment
cr_no_alignment is really only used by the alignment code.  Since we no
longer change the setting of cr_alignment after boot, we can localise
this to alignment.c

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-02 09:20:18 +01:00
Russell King 3cb099f089 ARM: remove CPU_CP15 conditional from alignment.c
alignment.c will not be built unless CPU_CP15 is set:

config CPU_CP15
        bool

config CPU_CP15_MMU
        bool
        select CPU_CP15

config ALIGNMENT_TRAP
        bool
        depends on CPU_CP15_MMU

So there's no point having conditionals on CPU_CP15 within this code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-02 09:20:16 +01:00
Russell King 175352a51c ARM: move "noalign" command line option to alignment.c
Keep all bits of alignment handling together.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-02 09:20:13 +01:00
Russell King b4b20ad881 ARM: provide common method to clear bits in CPU control register
Several places open-code this manipulation, let's consolidate this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-02 09:20:11 +01:00
Russell King 4585eaff63 ARM: use get_cr() rather than cr_alignment
Rather than reading the cr_alignment variable, use get_cr() to read
directly from the hardware instead.  We have two places where this
occurs, neither of them are performance critical.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-05-22 16:27:27 +01:00
Ben Dooks 8592edf0de ARM: alignment: correctly decode instructions in BE8 mode.
If we are in BE8 mode, we must deal with the instruction stream being
in LE order when data is being loaded in BE order. Ensure the data is
swapped before processing to avoid thre following:

Change to using <asm/opcodes.h> to provide the necessary conversion
functions to change the byte ordering.

This stops the following warning messages from the kernel on a fault:

Unhandled fault: alignment exception (0x001) at 0xbfa09567
Alignment trap: not handling instruction 030091e8 at [<80333e8c>]

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2013-10-19 20:46:34 +01:00
Russell King 73a09d212e Merge branch 'for-next' of git://git.pengutronix.de/git/ukl/linux into devel-stable
Conflicts:
	arch/arm/include/asm/cputype.h

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-03-09 15:49:32 +00:00
Russell King b255188f90 ARM: fix scheduling while atomic warning in alignment handling code
Paolo Pisati reports that IPv6 triggers this warning:

BUG: scheduling while atomic: swapper/0/0/0x40000100
Modules linked in:
[<c001b1c4>] (unwind_backtrace+0x0/0xf0) from [<c0503c5c>] (__schedule_bug+0x48/0x5c)
[<c0503c5c>] (__schedule_bug+0x48/0x5c) from [<c0508608>] (__schedule+0x700/0x740)
[<c0508608>] (__schedule+0x700/0x740) from [<c007007c>] (__cond_resched+0x24/0x34)
[<c007007c>] (__cond_resched+0x24/0x34) from [<c05086dc>] (_cond_resched+0x3c/0x44)
[<c05086dc>] (_cond_resched+0x3c/0x44) from [<c0021f6c>] (do_alignment+0x178/0x78c)
[<c0021f6c>] (do_alignment+0x178/0x78c) from [<c00083e0>] (do_DataAbort+0x34/0x98)
[<c00083e0>] (do_DataAbort+0x34/0x98) from [<c0509a60>] (__dabt_svc+0x40/0x60)
Exception stack(0xc0763d70 to 0xc0763db8)
3d60:                                     e97e805e e97e806e 2c000000 11000000
3d80: ea86bb00 0000002c 00000011 e97e807e c076d2a8 e97e805e e97e806e 0000002c
3da0: 3d000000 c0763dbc c04b98fc c02a8490 00000113 ffffffff
[<c0509a60>] (__dabt_svc+0x40/0x60) from [<c02a8490>] (__csum_ipv6_magic+0x8/0xc8)

Fix this by using probe_kernel_address() stead of __get_user().

Cc: <stable@vger.kernel.org>
Reported-by: Paolo Pisati <p.pisati@gmail.com>
Tested-by: Paolo Pisati <p.pisati@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-02-25 16:10:42 +00:00
Uwe Kleine-König b849a60e09 ARM: make cr_alignment read-only #ifndef CONFIG_CPU_CP15
This makes cr_alignment a constant 0 to break code that tries to modify
the value as it's likely that it's built on wrong assumption when
CONFIG_CPU_CP15 isn't defined. For code that is only reading the value 0
is more or less a fine value to report.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1358413196-5609-2-git-send-email-u.kleine-koenig@pengutronix.de (v8)
2013-01-31 21:44:45 +01:00
viresh kumar 6404f0b71c ARM: 7569/1: mm: uninitialized warning corrections
The variables here are really not used uninitialized.

arch/arm/mm/alignment.c: In function 'do_alignment':
arch/arm/mm/alignment.c:327:15: warning: 'offset.un' may be used uninitialized in this function [-Wmaybe-uninitialized]
arch/arm/mm/alignment.c:748:21: note: 'offset.un' was declared here

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-11-04 10:32:40 +00:00
Arnd Bergmann 31d2a638a9 ARM: Fix another build warning in arch/arm/mm/alignment.c
One such warning was recently fixed in a761cebf "ARM: Fix build warning
in arch/arm/mm/alignment.c" but only for the thumb2 case, this fixes
the other half.

arch/arm/mm/alignment.c: In function 'do_alignment':
arch/arm/mm/alignment.c:327:15: error: 'offset.un' may be used uninitialized in this function
arch/arm/mm/alignment.c:748:21: note: 'offset.un' was declared here

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
2012-10-09 20:24:36 +02:00
Russell King a761cebfd7 ARM: Fix build warning in arch/arm/mm/alignment.c
Fix this harmless build warning:

arch/arm/mm/alignment.c: In function 'do_alignment':
arch/arm/mm/alignment.c:749:21: warning: 'offset.un' may be used uninitialized in this function

This is caused by the compiler not being able to properly analyse the
code to prove that offset.un is assigned in every case.  The case it
struggles with is where we assign the handler from the Thumb parser -
do_alignment_t32_to_handler().  As this starts by zeroing this variable
via a pointer, move it into the calling function.  This fixes the
warning.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-15 21:43:31 +01:00
David Howells 9f97da78bf Disintegrate asm/system.h for ARM
Disintegrate asm/system.h for ARM.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org
2012-03-28 18:30:01 +01:00
Russell King 15d07dc9c5 ARM: move CP15 definitions to separate header file
Avoid namespace conflicts with drivers over the CP15 definitions by
moving CP15 related prototypes and definitions to a private header
file.

Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com> [Tegra]
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> [EP93xx]
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:01 +01:00
Catalin Marinas f7b8156d15 ARM: LPAE: Add fault handling support
The DFSR and IFSR register format is different when LPAE is enabled. In
addition, DFSR and IFSR have similar definitions for the fault type.
This modifies the fault code to correctly handle the new format.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-12-08 10:30:40 +00:00
Arnd Bergmann ffc660c51b ARM: allow building alignment.c without PROC_FS
The two functions cpu_is_v6_unaligned and safe_usermode
are only defined when CONFIG_PROC_FS is enabled, but
are used outside of the #ifdef.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Martin <dave.martin@linaro.org>
2011-10-01 21:08:54 +02:00
Dave Martin 2102a65e69 ARM: 7008/1: alignment: Make SIGBUS sent to userspace POSIXly correct
With the UM_SIGNAL alignment fault mode, no siginfo structure is
passed to userspace.

POSIX specifies how siginfo_t should be populated for alignment
faults, so this patch does just that:

  * si_signo = SIGBUS
  * si_code = BUS_ADRALN
  * si_addr = misaligned data address at which access was attempted

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-09 08:42:39 +01:00
Dave Martin 088c01f1e3 ARM: 7007/1: alignment: Prevent ignoring of faults with ARMv6 unaligned access model
Currently, it's possible to set the kernel to ignore alignment
faults when changing the alignment fault handling mode at runtime
via /proc/sys/alignment, even though this is undesirable on ARMv6
and above, where it can result in infinite spins where an un-fixed-
up instruction repeatedly faults.

In addition, the kernel clobbers any alignment mode specified on
the command-line if running on ARMv6 or above.

This patch factors out the necessary safety check into a couple of
new helper functions, and checks and modifies the fault handling
mode as appropriate on boot and on writes to /proc/cpu/alignment.

Prior to ARMv6, the behaviour is unchanged.

For ARMv6 and above, the behaviour changes as follows:

  * Attempting to ignore faults on ARMv6 results in the mode being
    forced to UM_FIXUP instead.  A warning is printed if this
    happened as a result of a write to /proc/cpu/alignment.  The
    user's UM_WARN bit (if present) is still honoured.

  * An alignment= argument from the kernel command-line is now
    honoured, except that the kernel will modify the specified mode
    as described above.  This is allows modes such as UM_SIGNAL and
    UM_WARN to be active immediately from boot, which is useful for
    debugging purposes.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-09 08:42:39 +01:00
Russell King 02fe2845d6 ARM: entry: avoid enabling interrupts in prefetch/data abort handlers
Avoid enabling interrupts if the parent context had interrupts enabled
in the abort handler assembly code, and move this into the breakpoint/
page/alignment fault handlers instead.

This gets rid of some special-casing for the breakpoint fault handlers
from the low level abort handler path.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02 10:56:00 +01:00
Nicolas Pitre 2f27bf834e ARM: 6401/1: plug a race in the alignment trap handler
When the policy for user space is to ignore misaligned accesses from user
space, the processor then performs a documented rotation on the accessed
data.  This is the result of the access being trapped, and the kernel
disabling the alignment trap before returning to user space again.

In kernel space we always want misaligned accesses to be fixed up.  This
is enforced by always re-enabling the alignment trap on every entry into
kernel space from user space.  No such re-enabling is performed when an
exception occurs while already in kernel space as the alignment trap is
always supposed to be enabled in that case.

There is however a small race window when a misaligned access in user
space is trapped and the alignment trap disabled, but the CPU didn't
return to user space just yet.  Any exception would be entered from kernel
space at that point and the kernel would then execute with the alignment
trap disabled.

Thanks to Maxime Bizon <mbizon@freebox.fr> for providing a test module
that made this issue reproducible.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-23 15:17:04 +01:00
Kirill A. Shutemov b8ab5397bc ARM: 6268/1: ARMv6K and ARMv7 use fault statuses 3 and 6 as Access Flag fault
Statuses 3 (0b00011) and 6 (0x00110) of DFSR are Access Flags faults on
ARMv6K and ARMv7. Let's patch fsr_info[] at runtime if we are on ARMv7
or later.

Unfortunately, we don't have runtime check for 'K' extension, so we
can't check for it.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27 10:48:41 +01:00
Kirill A. Shutemov 6338a6aa7c ARM: 6269/1: Add 'code' parameter for hook_fault_code()
Add one more parameter to hook_fault_code() to be able to set 'code'
field of struct fsr_info.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27 10:48:34 +01:00
Kirill A. Shutemov 3dc91aff9c ARM: 6252/1: Use SIGBUS for unaligned access instead of SIGILL
POSIX specify to use signal SIGBUS with code BUS_ADRALN for invalid
address alignment.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27 10:43:49 +01:00
Russell King ac1d426e82 Merge branch 'devel-stable' into devel
Conflicts:
	arch/arm/Kconfig
	arch/arm/include/asm/system.h
	arch/arm/mm/Kconfig
2010-05-17 17:24:04 +01:00
Alexey Dobriyan b7072c63c1 ARM: convert /proc/cpu/aligment to seq_file
Convert code away from ->read_proc/->write_proc interfaces.  Switch to
proc_create()/proc_create_data() which makes addition of proc entries
reliable wrt NULL ->proc_fops, NULL ->data and so on.

Problem with ->read_proc et al is described here commit
786d7e1612 "Fix rmmod/read/write races in
/proc entries"

This patch is part of an effort to remove the old simple procfs PAGE_SIZE
buffer interface.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-05-15 15:03:48 +01:00
Russell King 4260415f6a ARM: fix build error in arch/arm/kernel/process.c
/tmp/ccJ3ssZW.s: Assembler messages:
/tmp/ccJ3ssZW.s:1952: Error: can't resolve `.text' {.text section} - `.LFB1077'

This is caused because:

	.section .data
	.section .text
	.section .text
	.previous

does not return us to the .text section, but the .data section; this
makes use of .previous dangerous if the ordering of previous sections
is not known.

Fix up the other users of .previous; .pushsection and .popsection are
a safer pairing to use than .section and .previous.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-04-21 08:45:21 +01:00
Linus Torvalds ac0f6f927d Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (100 commits)
  ARM: Eliminate decompressor -Dstatic= PIC hack
  ARM: 5958/1: ARM: U300: fix inverted clk round rate
  ARM: 5956/1: misplaced parentheses
  ARM: 5955/1: ep93xx: move timer defines into core.c and document
  ARM: 5954/1: ep93xx: move gpio interrupt support to gpio.c
  ARM: 5953/1: ep93xx: fix broken build of clock.c
  ARM: 5952/1: ARM: MM: Add ARM_L1_CACHE_SHIFT_6 for handle inside each ARCH Kconfig
  ARM: 5949/1: NUC900 add gpio virtual memory map
  ARM: 5948/1: Enable timer0 to time4 clock support for nuc910
  ARM: 5940/2: ARM: MMCI: remove custom DBG macro and printk
  ARM: make_coherent(): fix problems with highpte, part 2
  MM: Pass a PTE pointer to update_mmu_cache() rather than the PTE itself
  ARM: 5945/1: ep93xx: include correct irq.h in core.c
  ARM: 5933/1: amba-pl011: support hardware flow control
  ARM: 5930/1: Add PKMAP area description to memory.txt.
  ARM: 5929/1: Add checks to detect overlap of memory regions.
  ARM: 5928/1: Change type of VMALLOC_END to unsigned long.
  ARM: 5927/1: Make delimiters of DMA area globally visibly.
  ARM: 5926/1: Add "Virtual kernel memory..." printout.
  ARM: 5920/1: OMAP4: Enable L2 Cache
  ...

Fix up trivial conflict in arch/arm/mach-mx25/clock.c
2010-03-01 09:15:15 -08:00
Russell King d944d549aa ARM: allow alignment fault mode to be configured at kernel boot
Some glibc versions intentionally create lots of alignment faults in
their gconv code, which if not fixed up, results in segfaults during
boot.  This can prevent systems booting properly.

There is no clear hard-configurable default for this; the desired
default depends on the nature of the userspace which is going to be
booted.

So, provide a way for the alignment fault handler to be configured via
the kernel command line.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-20 16:20:49 +00:00
Russell King e119bfff1f ARM: Move creation of /proc/cpu out of alignment.c
Always creating this directory avoids other users having to jump
through silly hoops when they want to share this directory.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:39:12 +00:00
Catalin Marinas 347c8b70b1 Thumb-2: Implement the unified arch/arm/mm support
This patch adds the ARM/Thumb-2 unified support to the arch/arm/mm/*
files.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-07-24 12:32:56 +01:00
George G. Davis c2860d43f5 [ARM] 5540/1: 32-bit Thumb-2 {ld,st}{m,rd} alignment fault fixup support
From: Min Zhang <mzhang@mvista.com>

Add alignment fault fixup support for 32-bit Thumb-2 LDM, LDRD, POP,
PUSH, STM and STRD instructions.  Alignment fault fixup support for
the remaining 32-bit Thumb-2 load/store instruction cases is not
included since ARMv6 and later processors include hardware support
for loads and stores of unaligned words and halfwords.

Signed-off-by: Min Zhang <mzhang@mvista.com>
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-06-19 16:35:34 +01:00
Russell King 7e1548a597 Merge branch 'omap3-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6 into devel 2008-12-15 22:13:26 +00:00
Russell King baa745a337 [ARM] Fix alignment fault handling for ARMv6 and later CPUs
On ARMv6 and later CPUs, it is possible for userspace processes to
get stuck on a misaligned load or store due to the "ignore fault"
setting; unlike previous CPUs, retrying the instruction without
the 'A' bit set does not always cause the load to succeed.

We have no real option but to default to fixing up alignment faults
on these CPUs, and having the CPU fix up those misaligned accesses
which it can.

Reported-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-12-07 09:44:55 +00:00
Russell King 87c52578bd [ARM] Remove linux/sched.h from asm/cacheflush.h and asm/uaccess.h
... and fix those drivers that were incorrectly relying upon
that include.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-29 18:49:55 +00:00
Russell King 33fa9b1328 [ARM] Convert asm/uaccess.h to linux/uaccess.h
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-06 11:35:55 +01:00
Alexey Dobriyan 19c5870c0e Use helpers to obtain task pid in printks (arch code)
One of the easiest things to isolate is the pid printed in kernel log.
There was a patch, that made this for arch-independent code, this one makes
so for arch/xxx files.

It took some time to cross-compile it, but hopefully these are all the
printks in arch code.

Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:43 -07:00