Commit Graph

64 Commits

Author SHA1 Message Date
Will Deacon b10bca0bc6 ARM: 7595/1: syscall: rework ordering in syscall_trace_exit
syscall_trace_exit is currently doing things back-to-front; invoking
the audit hook *after* signalling the debugger, which presents an
opportunity for the registers to be re-written by userspace in order to
bypass auditing constaints.

This patch fixes the ordering by moving the audit code first and the
tracehook code last. On the face of it, it looks like
current_thread_info()->syscall may be incorrect for the sys_exit
tracepoint, but that's actually not an issue because it will have been
set during syscall entry and cannot have changed since then.

Reported-by: Andrew Gabbasov <Andrew_Gabbasov@mentor.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-12-11 00:18:26 +00:00
Kees Cook 9b790d71d5 ARM: 7578/1: arch/move secure_computing into trace
There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_WORK
path in entry-common.S, so merge TIF_SECCOMP into TIF_SYSCALL_WORK and
move seccomp into the syscall_trace_enter() handler.

Expanded some of the tracehook logic into the callers to make this code
more readable. Since tracehook needs to do register changing, this portion
is best left in its own function instead of copy/pasting into the callers.

Additionally, the return value for secure_computing() is now checked
and a -1 value will result in the system call being skipped.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Drewry <wad@chromium.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-11-19 14:14:17 +00:00
Will Deacon ebb5e15c3e ARM: 7525/1: ptrace: use updated syscall number for syscall auditing
When tracing system calls, a debugger may change the syscall number
in response to a SIGTRAP on syscall entry.

This patch ensures that the new syscall number is passed to the audit
code.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-19 21:50:50 +01:00
Wade Farnsworth 1f66e06fb6 ARM: 7524/1: support syscall tracing
As specified by ftrace-design.txt, TIF_SYSCALL_TRACEPOINT was
added, as well as NR_syscalls in asm/unistd.h.  Additionally,
__sys_trace was modified to call trace_sys_enter and
trace_sys_exit when appropriate.

Tests #2 - #4 of "perf test" now complete successfully.

Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Signed-off-by: Wade Farnsworth <wade_farnsworth@mentor.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-19 21:50:48 +01:00
Al Viro 6628521784 ARM: 7474/1: get rid of TIF_SYSCALL_RESTARTSYS
just let do_work_pending() return 1 on normal local restarts and
-1 on those that had been caused by ERESTART_RESTARTBLOCK (and 0
is still "all done, sod off to userland now").  And let the asm
glue flip scno to restart_syscall(2) one if it got negative from
us...

[will: resolved conflicts with audit fixes]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-28 11:11:52 +01:00
Will Deacon ad82cc08f7 ARM: 7470/1: Revert "7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK""
This reverts commit 433e2f307b.

Conflicts:

	arch/arm/kernel/ptrace.c

Reintroduce the new syscall restart handling in preparation for further
patches from Al Viro.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-28 11:11:51 +01:00
Will Deacon ad72254114 ARM: 7456/1: ptrace: provide separate functions for tracing syscall {entry,exit}
The syscall_trace on ARM takes a `why' parameter to indicate whether or
not we are entering or exiting a system call. This can be confusing for
people looking at the code since (a) it conflicts with the why register
alias in the entry assembly code and (b) it is not immediately clear
what it represents.

This patch splits up the syscall_trace function into separate wrappers
for syscall entry and exit, allowing the low-level syscall handling
code to branch to the appropriate function.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:44:14 +01:00
Will Deacon 5125430ccc ARM: 7455/1: audit: move syscall auditing until after ptrace SIGTRAP handling
When auditing system calls on ARM, the audit code is called before
notifying the parent process in the case that the current task is being
ptraced. At this point, the parent (debugger) may choose to change the
system call being issued via the SET_SYSCALL ptrace request, causing
the wrong system call to be reported to the audit tools.

This patch moves the audit calls after the ptrace SIGTRAP handling code
in the syscall tracing implementation.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:44:14 +01:00
Will Deacon 433e2f307b ARM: 7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK"
This reverts commit 6b5c8045ec.

Conflicts:

	arch/arm/kernel/ptrace.c

The new syscall restarting code can lead to problems if we take an
interrupt in userspace just before restarting the svc instruction. If
a signal is delivered when returning from the interrupt, the
TIF_SYSCALL_RESTARTSYS will remain set and cause any syscalls executed
from the signal handler to be treated as a restart of the previously
interrupted system call. This includes the final sigreturn call, meaning
that we may fail to exit from the signal context. Furthermore, if a
system call made from the signal handler requires a restart via the
restart_block, it is possible to clear the thread flag and fail to
restart the originally interrupted system call.

The right solution to this problem is to perform the restarting in the
kernel, avoiding the possibility of handling a further signal before the
restart is complete. Since we're almost at -rc6, let's revert the new
method for now and aim for in-kernel restarting at a later date.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-05 09:50:56 +01:00
Russell King e94c805f0c Merge branch 'for-arm' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal.git into for-linus
Conflicts:
	arch/arm/kernel/ptrace.c
2012-05-29 22:13:55 +01:00
Al Viro 70b58d896b arm: don't open-code ptrace_report_syscall()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21 14:40:44 -04:00
Al Viro 6b5c8045ec arm: new way of handling ERESTART_RESTARTBLOCK
new "syscall start" flag; handled in syscall_trace() by switching
syscall number to that of syscall_restart(2).  Restarts of that
kind (ERESTART_RESTARTBLOCK) are handled by setting that bit;
syscall number is not modified until the actual call.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21 14:39:11 -04:00
Russell King 4175160b06 Merge branch 'misc' into for-linus
Conflicts:
	arch/arm/kernel/ptrace.c
2012-05-21 15:15:24 +01:00
Will Deacon 2f97836698 ARM: 7412/1: audit: use only AUDIT_ARCH_ARM regardless of endianness
The machine endianness has no direct correspondence to the syscall ABI,
so use only AUDIT_ARCH_ARM when identifying the ABI to the audit tools
in userspace.

Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-05-05 13:54:01 +01:00
Will Deacon 6a68b6f574 ARM: 7411/1: audit: fix treatment of saved ip register during syscall tracing
The ARM audit code incorrectly uses the saved application ip register
value to infer syscall entry or exit. Additionally, the saved value will
be clobbered if the current task is not being traced, which can lead to
libc corruption if ip is live (apparently glibc uses it for the TLS
pointer).

This patch fixes the syscall tracing code so that the why parameter is
used to infer the syscall direction and the saved ip is only updated if
we know that we will be signalling a ptrace trap.

Reported-and-Tested-by: Jon Masters <jcm@jonmasters.org>

Cc: stable@vger.kernel.org
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-05-05 13:54:01 +01:00
Wade Farnsworth 0693bf6814 ARM: 7374/1: add TRACEHOOK support
Add calls to tracehook_report_syscall_{entry,exit} and tracehook_signal_handler

Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Signed-off-by: Wade Farnsworth <wade_farnsworth@mentor.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-04-25 19:49:28 +01:00
Will Deacon 5a4f5da543 ARM: 7337/1: ptrace: fix ptrace_read_user for !CONFIG_MMU platforms
Commit 68b7f715 ("nommu: ptrace support") added definitions for
PT_TEXT_ADDR and friends, as well as adding ptrace support for reading
from these magic offsets.

Unfortunately, this has probably never worked, since ptrace_read_user
predicates reading on off < sizeof(struct user), returning -EIO
otherwise.

This patch moves the offset size check until after we have tried to
match it against either a magic value or an offset into pt_regs.

Cc: Paul Brook <paul@codesourcery.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-30 12:17:33 +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
Eric Paris 5180bb392a ARM/audit: include audit header and fix audit arch
Both bugs being fixed were introduced in:
29ef73b7a8

Include linux/audit.h to fix below build errors:

  CC      arch/arm/kernel/ptrace.o
arch/arm/kernel/ptrace.c: In function 'syscall_trace':
arch/arm/kernel/ptrace.c:919: error: implicit declaration of function 'audit_syscall_exit'
arch/arm/kernel/ptrace.c:921: error: implicit declaration of function 'audit_syscall_entry'
arch/arm/kernel/ptrace.c:921: error: 'AUDIT_ARCH_ARMEB' undeclared (first use in this function)
arch/arm/kernel/ptrace.c:921: error: (Each undeclared identifier is reported only once
arch/arm/kernel/ptrace.c:921: error: for each function it appears in.)
make[1]: *** [arch/arm/kernel/ptrace.o] Error 1
make: *** [arch/arm/kernel] Error 2

This part of the patch is:
Reported-by: Axel Lin <axel.lin@gmail.com>
Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
(They both provided patches to fix it)

This patch also (at the request of the list) fixes the fact that
ARM has both LE and BE versions however the audit code was called as if
it was always BE.  If audit userspace were to try to interpret the bits
it got from a LE system it would obviously do so incorrectly.  Fix this
by using the right arch flag on the right system.

This part of the patch is:
Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk>

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-02-21 16:50:14 +00:00
Will Deacon 8130b9d7b9 ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers
If we are context switched whilst copying into a thread's
vfp_hard_struct then the partial copy may be corrupted by the VFP
context switching code (see "ARM: vfp: flush thread hwstate before
restoring context from sigframe").

This patch updates the ptrace VFP set code so that the thread state is
flushed before the copy, therefore disabling VFP and preventing
corruption from occurring.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-02-02 17:37:42 +00:00
Dave Martin 247f4993a5 ARM: 7307/1: vfp: fix ptrace regset modification race
In a preemptible kernel, vfp_set() can be preempted, causing the
hardware VFP context to be switched while the thread vfp state is
being read and modified.  This leads to a race condition which can
cause the thread vfp state to become corrupted if lazy VFP context
save occurs due to preemption in between the time thread->vfpstate
is read and the time the modified state is written back.

This may occur if preemption occurs during the execution of a
ptrace() call which modifies the VFP register state of a thread.
Such instances should be very rare in most realistic scenarios --
none has been reported, so far as I am aware.  Only uniprocessor
systems should be affected, since VFP context save is not currently
lazy in SMP kernels.

The problem was introduced by my earlier patch migrating to use
regsets to implement ptrace.

This patch does a vfp_sync_hwstate() before reading
thread->vfpstate, to make sure that the thread's VFP state is not
live in the hardware registers while the registers are modified.

Thanks to Will Deacon for spotting this.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-02-02 17:37:42 +00:00
Nathaniel Husted 29ef73b7a8 Kernel: Audit Support For The ARM Platform
This patch provides functionality to audit system call events on the
ARM platform. The implementation was based off the structure of the
MIPS platform and information in this
(http://lists.fedoraproject.org/pipermail/arm/2009-October/000382.html)
mailing list thread. The required audit_syscall_exit and
audit_syscall_entry checks were added to ptrace using the standard
registers for system call values (r0 through r3). A thread information
flag was added for auditing (TIF_SYSCALL_AUDIT) and a meta-flag was
added (_TIF_SYSCALL_WORK) to simplify modifications to the syscall
entry/exit. Now, if either the TRACE flag is set or the AUDIT flag is
set, the syscall_trace function will be executed. The prober changes
were made to Kconfig to allow CONFIG_AUDITSYSCALL to be enabled.

Due to platform availability limitations, this patch was only tested
on the Android platform running the modified "android-goldfish-2.6.29"
kernel. A test compile was performed using Code Sourcery's
cross-compilation toolset and the current linux-3.0 stable kernel. The
changes compile without error. I'm hoping, due to the simple modifications,
the patch is "obviously correct".

Signed-off-by: Nathaniel Husted <nhusted@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-17 16:17:01 -05:00
Paul Gortmaker ce8b9d25c9 arm: add elf.h to arch/arm/kernel/ptrace.c
It was implicitly getting it via an implicit presence of module.h
but when we clean that up, we'll get a bunch of lines like this:

arch/arm/kernel/ptrace.c:764: error: 'NT_PRSTATUS' undeclared here (not in a function)
arch/arm/kernel/ptrace.c:765: error: 'ELF_NGREG' undeclared here (not in a function)
arch/arm/kernel/ptrace.c:776: error: 'NT_PRFPREG' undeclared here (not in a function)

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:45 -04:00
Linus Torvalds b6844e8f64 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: (237 commits)
  ARM: 7004/1: fix traps.h compile warnings
  ARM: 6998/2: kernel: use proper memory barriers for bitops
  ARM: 6997/1: ep93xx: increase NR_BANKS to 16 for support of 128MB RAM
  ARM: Fix build errors caused by adding generic macros
  ARM: CPU hotplug: ensure we migrate all IRQs off a downed CPU
  ARM: CPU hotplug: pass in proper affinity mask on IRQ migration
  ARM: GIC: avoid routing interrupts to offline CPUs
  ARM: CPU hotplug: fix abuse of irqdesc->node
  ARM: 6981/2: mmci: adjust calculation of f_min
  ARM: 7000/1: LPAE: Use long long printk format for displaying the pud
  ARM: 6999/1: head, zImage: Always Enter the kernel in ARM state
  ARM: btc: avoid invalidating the branch target cache on kernel TLB maintanence
  ARM: ARM_DMA_ZONE_SIZE is no more
  ARM: mach-shark: move ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
  ARM: mach-sa1100: move ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
  ARM: mach-realview: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
  ARM: mach-pxa: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
  ARM: mach-ixp4xx: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
  ARM: mach-h720x: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
  ARM: mach-davinci: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
  ...
2011-07-24 10:20:54 -07:00
Jon Medhurst 592201a9f1 ARM: Thumb-2: Support Thumb-2 in undefined instruction handler
This patch allows undef_hook's to be specified for 32-bit Thumb
instructions and also to be used for thumb kernel-side code.

32-bit Thumb instructions are specified in the form:
	((first_half << 16 ) | second_half)
which matches the layout used by the ARM ARM.

ptrace was handling 32-bit Thumb instructions by hooking the first
halfword and manually checking the second half. This method would be
broken by this patch so it is migrated to make use of the new Thumb-2
support.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-07-13 17:32:40 +00:00
Avi Kivity 4dc0da8696 perf: Add context field to perf_event
The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure.  This is ugly and doesn't scale if a
single callback services many perf_events.

Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event->overflow_handler_context.
All callers are updated.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-01 11:06:38 +02:00
Peter Zijlstra a8b0ca17b8 perf: Remove the nmi parameter from the swevent and overflow interface
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-01 11:06:35 +02:00
Dave Martin 5be6f62b00 ARM: 6883/1: ptrace: Migrate to regsets framework
This patch migrates the implementation of the ptrace interface for
the core integer registers, legacy FPA registers and VFP registers
to use the regsets framework.

As an added bonus, all this stuff gets included in coredumps
at no extra cost.  Without this patch, coredumps contained no
VFP state.

Third-party extension register sets (iwmmx, crunch) are not migrated
by this patch, and continue to use the old implementation;
these should be migratable without much extra work.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-14 21:36:55 +01:00
Frederic Weisbecker bf0b8f4b55 arm, hw_breakpoints: Fix racy access to ptrace breakpoints
While the tracer accesses ptrace breakpoints, the child task may
concurrently exit due to a SIGKILL and thus release its breakpoints
at the same time. We can then dereference some freed pointers.

To fix this, hold a reference on the child breakpoints before
manipulating them.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/1302284067-7860-5-git-send-email-fweisbec@gmail.com
2011-04-25 17:35:18 +02:00
Russell King 1f0090a1ea Merge branch 'misc' into devel
Conflicts:
	arch/arm/Kconfig
2011-03-16 23:35:25 +00:00
Will Deacon ba55d3db9b ARM: 6767/1: ptrace: fix register indexing in GETHBPREGS request
The GETHBPREGS ptrace request incorrectly maps its index argument onto
the thread's saved debug state when the index != 0. This has not yet
been seen from userspace because GDB (the only user of this request)
only reads from register 0.

This patch fixes the indexing.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-26 13:35:50 +00:00
Will Deacon 425fc47adb ARM: 6668/1: ptrace: remove single-step emulation code
PTRACE_SINGLESTEP is a ptrace request designed to offer single-stepping
support to userspace when the underlying architecture has hardware
support for this operation.

On ARM, we set arch_has_single_step() to 1 and attempt to emulate hardware
single-stepping by disassembling the current instruction to determine the
next pc and placing a software breakpoint on that location.

Unfortunately this has the following problems:

1.) Only a subset of ARMv7 instructions are supported
2.) Thumb-2 is unsupported
3.) The code is not SMP safe

We could try to fix this code, but it turns out that because of the above
issues it is rarely used in practice.  GDB, for example, uses PTRACE_POKETEXT
and PTRACE_PEEKTEXT to manage breakpoints itself and does not require any
kernel assistance.

This patch removes the single-step emulation code from ptrace meaning that
the PTRACE_SINGLESTEP request will return -EIO on ARM. Portable code must
check the return value from a ptrace call and handle the failure gracefully.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-23 17:24:22 +00:00
Will Deacon ce9b1b0952 ARM: ptrace: fix style issue with hw_breakpoint interface
This patch fixes a trivial style issue in ptrace.c.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2010-12-06 11:55:57 +00:00
Namhyung Kim b640a0d192 ptrace: cleanup arch_ptrace() on ARM
use new 'datap' variable in order to remove unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim 9b05a69e05 ptrace: change signature of arch_ptrace()
Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Will Deacon 864232fa1a ARM: 6357/1: hw-breakpoint: add new ptrace requests for hw-breakpoint interaction
For debuggers to take advantage of the hw-breakpoint framework in the kernel,
it is necessary to expose the API calls via a ptrace interface.

This patch exposes the hardware breakpoints framework as a collection of
virtual registers, accesible using PTRACE_SETHBPREGS and PTRACE_GETHBPREGS
requests. The breakpoints are stored in the debug_info struct of the running
thread.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: S. Karthikeyan <informkarthik@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-08 10:05:00 +01:00
Will Deacon e513f8bf24 ARM: 6199/1: Add kprobe-based event tracer
This patch enables the HAVE_REGS_AND_STACK_ACCESS_API option
for ARM which is required by the kprobe events tracer. Code based
on the PowerPC port.

Cc: Jean Pihet <jpihet@mvista.com>
Tested-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-09 14:41:34 +01:00
Christoph Hellwig 440e6ca79a arm: use generic ptrace_resume code
Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP.  This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.

Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't and the single stepping disable only happens if the
tracee process isn't a zombie yet, which is consistent with all
architectures using the modern ptrace code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:38 -08:00
Russell King ad187f9561 ARM: vfp ptrace: no point flushing hw context for PTRACE_GETVFPREGS
If we're only reading the VFP context via the ptrace call, there's
no need to invalidate the hardware context - we only need to do that
on PTRACE_SETVFPREGS.  This allows more efficient monitoring of a
traced task.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:39:53 +00:00
Russell King 462f39a8c7 ARM: ptrace: get rid of PTRACE_{PEEK,POKE}{TEXT,DATA}
The generic ptrace_request() handles these for us, so there's no
need to duplicate them in arch code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:39:52 +00:00
Daniel Jacobowitz d23bc1b3a7 ARM: 5912/1: Define a 32-bit Thumb-2 breakpoint instruction
Recognize 0xf7f0 0xa000 as a 32-bit breakpoint instruction for
Thumb-2.

Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:39:52 +00:00
Paul Brook 68b7f7153f nommu: ptrace support
The patch below adds ARM ptrace functions to get the process load address.
This is required for useful userspace debugging on mmuless systems.  These
values are obtained by reading magic offsets with PTRACE_PEEKUSR, as on other
nommu targets. I picked arbitrary large values for the offsets.

Signed-off-by: Paul Brook <paul@codesourcery.com>
2009-07-24 12:34:58 +01:00
Catalin Marinas 3d1228ead6 [ARM] 5387/1: Add ptrace VFP support on ARM
This patch adds ptrace support for setting and getting the VFP registers
using PTRACE_SETVFPREGS and PTRACE_GETVFPREGS. The user_vfp structure
defined in asm/user.h contains 32 double registers (to cover VFPv3 and
Neon hardware) and the FPSCR register.

Cc: Paul Brook <paul@codesourcery.com>
Cc: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-12 10:59:43 +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
Russell King 1de765c1e9 [ARM] remove pc_pointer()
pc_pointer() was a function to mask the PC for 26-bit ARMs, which
we no longer support.  Remove it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-06 10:35:51 +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
Alexey Dobriyan 1bcf548293 Consolidate PTRACE_DETACH
Identical handlers of PTRACE_DETACH go into ptrace_request().
Not touching compat code.
Not touching archs that don't call ptrace_request.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:49 -07:00
Alexey Dobriyan f284ce7269 PTRACE_POKEDATA consolidation
Identical implementations of PTRACE_POKEDATA go into generic_ptrace_pokedata()
function.

AFAICS, fix bug on xtensa where successful PTRACE_POKEDATA will nevertheless
return EPERM.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:03 -07:00
Alexey Dobriyan 7664732315 PTRACE_PEEKDATA consolidation
Identical implementations of PTRACE_PEEKDATA go into generic_ptrace_peekdata()
function.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:03 -07:00
Randy Dunlap e63340ae6b header cleaning: don't include smp_lock.h when not used
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:07 -07:00