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2013-07-09ptrace/arm: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"Oleg Nesterov1-8/+0
This reverts commit bf0b8f4b55e5 ("hw_breakpoints: Fix racy access to ptrace breakpoints"). The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL"), the __TASK_TRACED tracee can't be woken up and ->ptrace_bps[] can't go away. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Prasad <prasad@linux.vnet.ibm.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>
2013-06-24ARM: 7735/2: Preserve the user r/w register TPIDRURW on context switch and forkAndré Hentschel1-1/+1
Since commit 6a1c53124aa1 the user writeable TLS register was zeroed to prevent it from being used as a covert channel between two tasks. There are more and more applications coming to Windows RT, Wine could support them, but mostly they expect to have the thread environment block (TEB) in TPIDRURW. This patch preserves that register per thread instead of clearing it. Unlike the TPIDRURO, which is already switched, the TPIDRURW can be updated from userspace so needs careful treatment in the case that we modify TPIDRURW and call fork(). To avoid this we must always read TPIDRURW in copy_thread. Signed-off-by: André Hentschel <nerv@dawncrow.de> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-12-11ARM: 7595/1: syscall: rework ordering in syscall_trace_exitWill Deacon1-9/+15
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>
2012-11-19ARM: 7578/1: arch/move secure_computing into traceKees Cook1-9/+20
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>
2012-09-19ARM: 7525/1: ptrace: use updated syscall number for syscall auditingWill Deacon1-6/+6
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>
2012-09-19ARM: 7524/1: support syscall tracingWade Farnsworth1-2/+9
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>
2012-07-28ARM: 7474/1: get rid of TIF_SYSCALL_RESTARTSYSAl Viro1-6/+1
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>
2012-07-28ARM: 7470/1: Revert "7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK""Will Deacon1-1/+7
This reverts commit 433e2f307beff8adba241646ce9108544e0c5a03. 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>
2012-07-09ARM: 7456/1: ptrace: provide separate functions for tracing syscall {entry,exit}Will Deacon1-12/+25
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>
2012-07-09ARM: 7455/1: audit: move syscall auditing until after ptrace SIGTRAP handlingWill Deacon1-8/+9
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>
2012-07-05ARM: 7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK"Will Deacon1-3/+0
This reverts commit 6b5c8045ecc7e726cdaa2a9d9c8e5008050e1252. 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>
2012-05-29Merge branch 'for-arm' of ↵Russell King1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal.git into for-linus Conflicts: arch/arm/kernel/ptrace.c
2012-05-21arm: don't open-code ptrace_report_syscall()Al Viro1-14/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21arm: new way of handling ERESTART_RESTARTBLOCKAl Viro1-0/+3
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>
2012-05-21Merge branch 'misc' into for-linusRussell King1-15/+6
Conflicts: arch/arm/kernel/ptrace.c
2012-05-05ARM: 7412/1: audit: use only AUDIT_ARCH_ARM regardless of endiannessWill Deacon1-7/+1
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>
2012-05-05ARM: 7411/1: audit: fix treatment of saved ip register during syscall tracingWill Deacon1-8/+8
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>
2012-04-25ARM: 7374/1: add TRACEHOOK supportWade Farnsworth1-15/+6
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>
2012-03-30ARM: 7337/1: ptrace: fix ptrace_read_user for !CONFIG_MMU platformsWill Deacon1-1/+3
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>
2012-03-28Disintegrate asm/system.h for ARMDavid Howells1-1/+0
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
2012-02-21ARM/audit: include audit header and fix audit archEric Paris1-1/+8
Both bugs being fixed were introduced in: 29ef73b7a823b77a7cd0bdd7d7cded3fb6c2587b 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>
2012-02-02ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registersWill Deacon1-1/+1
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>
2012-02-02ARM: 7307/1: vfp: fix ptrace regset modification raceDave Martin1-2/+4
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>
2012-01-17Kernel: Audit Support For The ARM PlatformNathaniel Husted1-5/+11
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>
2011-10-31arm: add elf.h to arch/arm/kernel/ptrace.cPaul Gortmaker1-0/+1
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>
2011-07-24Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds1-25/+3
* '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 ...
2011-07-13ARM: Thumb-2: Support Thumb-2 in undefined instruction handlerJon Medhurst1-25/+3
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>
2011-07-01perf: Add context field to perf_eventAvi Kivity1-1/+2
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>
2011-07-01perf: Remove the nmi parameter from the swevent and overflow interfacePeter Zijlstra1-1/+1
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>
2011-05-14ARM: 6883/1: ptrace: Migrate to regsets frameworkDave Martin1-109/+239
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>
2011-04-25arm, hw_breakpoints: Fix racy access to ptrace breakpointsFrederic Weisbecker1-0/+8
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
2011-03-16Merge branch 'misc' into develRussell King1-382/+1
Conflicts: arch/arm/Kconfig
2011-02-26ARM: 6767/1: ptrace: fix register indexing in GETHBPREGS requestWill Deacon1-3/+3
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>
2011-02-23ARM: 6668/1: ptrace: remove single-step emulation codeWill Deacon1-382/+1
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>
2010-12-06ARM: ptrace: fix style issue with hw_breakpoint interfaceWill Deacon1-2/+2
This patch fixes a trivial style issue in ptrace.c. Signed-off-by: Will Deacon <will.deacon@arm.com>
2010-10-27ptrace: cleanup arch_ptrace() on ARMNamhyung Kim1-12/+13
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>
2010-10-27ptrace: change signature of arch_ptrace()Namhyung Kim1-1/+2
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>
2010-09-08ARM: 6357/1: hw-breakpoint: add new ptrace requests for hw-breakpoint ↵Will Deacon1-0/+239
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>
2010-07-09ARM: 6199/1: Add kprobe-based event tracerWill Deacon1-0/+96
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>
2010-03-12arm: use generic ptrace_resume codeChristoph Hellwig1-48/+12
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>
2010-02-15ARM: vfp ptrace: no point flushing hw context for PTRACE_GETVFPREGSRussell King1-2/+4
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>
2010-02-15ARM: ptrace: get rid of PTRACE_{PEEK,POKE}{TEXT,DATA}Russell King1-16/+0
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>
2010-02-15ARM: 5912/1: Define a 32-bit Thumb-2 breakpoint instructionDaniel Jacobowitz1-0/+31
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>
2009-07-24nommu: ptrace supportPaul Brook1-1/+7
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>
2009-02-12[ARM] 5387/1: Add ptrace VFP support on ARMCatalin Marinas1-0/+58
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>
2008-09-06[ARM] Convert asm/uaccess.h to linux/uaccess.hRussell King1-1/+1
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-06[ARM] remove pc_pointer()Russell King1-5/+3
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>
2007-10-19Use helpers to obtain task pid in printks (arch code)Alexey Dobriyan1-4/+4
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>
2007-10-16Consolidate PTRACE_DETACHAlexey Dobriyan1-4/+0
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>
2007-07-17PTRACE_POKEDATA consolidationAlexey Dobriyan1-6/+1
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>