kernel-ark/arch/arm/kernel
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
..
.gitignore
armksyms.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
arthur.c
asm-offsets.c ARM: 7114/1: cache-l2x0: add resume entry for l2 in secure mode 2011-10-17 09:11:51 +01:00
atags.c
atags.h
bios32.c arm/PCI: convert to pci_scan_root_bus() for correct root bus resources 2012-01-06 12:10:56 -08:00
calls.S ARM: wire up process_vm_writev and process_vm_readv syscalls 2011-11-17 16:58:00 +00:00
compat.c
compat.h
crash_dump.c crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn 2011-03-23 19:47:19 -07:00
crunch-bits.S
crunch.c
debug.S Merge branch 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm 2011-10-28 12:02:27 -07:00
devtree.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
dma-isa.c
dma.c locking, ARM: Annotate low level hw locks as raw 2011-09-13 11:12:14 +02:00
early_printk.c
ecard.c ARM: io: RiscPC: make EASI_BASE a void iomem pointer 2011-08-17 08:44:16 +01:00
ecard.h
elf.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
entry-armv.S Merge branch 'for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable 2011-12-05 23:20:17 +00:00
entry-common.S ARM: 7299/1: ftrace: clear zero bit in reported IPs for Thumb-2 2012-01-25 09:24:37 +00:00
entry-header.S Merge branch 'devel-stable' into for-next 2011-07-22 23:09:07 +01:00
etm.c arm: fix implicit module.h users by adding it to arch/arm as required. 2011-10-31 19:30:50 -04:00
fiq.c ARM: 6938/1: fiq: Refactor {get,set}_fiq_regs() for Thumb-2 2011-05-26 10:31:06 +01:00
fiqasm.S ARM: 6938/1: fiq: Refactor {get,set}_fiq_regs() for Thumb-2 2011-05-26 10:31:06 +01:00
ftrace.c
head-common.S arm/dt: Make __vet_atags also accept a dtb image 2011-05-11 15:12:32 +02:00
head-nommu.S ARM: 6999/1: head, zImage: Always Enter the kernel in ARM state 2011-07-19 12:00:53 +01:00
head.S ARM: 7275/1: LPAE: Check the CPU support for the long descriptor format 2012-01-13 08:56:41 +00:00
hw_breakpoint.c ARM: LPAE: Add fault handling support 2011-12-08 10:30:40 +00:00
init_task.c
io.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
irq.c arm: remove several unnecessary module.h include instances 2011-10-31 19:30:48 -04:00
isa.c
iwmmxt.S ARM: pxa: fix logic error in PJ4 iWMMXt handling 2011-08-11 10:10:26 +08:00
kgdb.c
kprobes-arm.c ARM: 7181/1: Restrict kprobes probing SWP instructions to ARMv5 and below 2011-11-30 23:54:54 +00:00
kprobes-common.c ARM: kprobes: Add alu_write_pc() 2011-07-13 17:32:48 +00:00
kprobes-test-arm.c ARM: 7181/1: Restrict kprobes probing SWP instructions to ARMv5 and below 2011-11-30 23:54:54 +00:00
kprobes-test-thumb.c ARM: 7174/1: Fix build error in kprobes test code on Thumb2 kernels 2011-11-26 21:58:53 +00:00
kprobes-test.c ARM: 7209/1: Use generic ARM instruction set condition code checks for kprobes. 2011-12-13 08:52:03 +00:00
kprobes-test.h ARM: 7174/1: Fix build error in kprobes test code on Thumb2 kernels 2011-11-26 21:58:53 +00:00
kprobes-thumb.c ARM: kprobes: Add exports for test code 2011-09-20 18:17:43 +00:00
kprobes.c ARM: kprobes: Extend arch_specific_insn to add pointer to emulated instruction 2011-07-13 17:32:42 +00:00
kprobes.h ARM: kprobes: Add exports for test code 2011-09-20 18:17:43 +00:00
leds.c arm: leds: convert sysdev_class to a regular subsystem 2011-12-21 15:52:57 -08:00
machine_kexec.c Merge branch 'restart-cleanup' into restart 2012-01-05 12:56:44 +00:00
Makefile ARM: 7206/1: Add generic ARM instruction set condition code checks. 2011-12-13 08:52:02 +00:00
module.c ARM: 7059/1: LPAE: Use PMD_(SHIFT|SIZE|MASK) instead of PGDIR_* 2011-08-23 15:30:33 +01:00
opcodes.c ARM: 7206/1: Add generic ARM instruction set condition code checks. 2011-12-13 08:52:02 +00:00
perf_event_v6.c ARM: perf: add support for stalled cycle ABI events 2011-12-02 15:16:16 +00:00
perf_event_v7.c ARM: perf: add support for stalled cycle ABI events 2011-12-02 15:16:16 +00:00
perf_event_xscale.c ARM: perf: add support for stalled cycle ABI events 2011-12-02 15:16:16 +00:00
perf_event.c Merge branch 'devel-stable' into for-linus 2012-01-05 13:24:33 +00:00
pj4-cp0.c arm: remove several unnecessary module.h include instances 2011-10-31 19:30:48 -04:00
pmu.c ARM: PMU: re-export release_pmu symbol to modules 2011-11-16 10:06:42 +00:00
process.c Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm 2012-01-06 18:15:25 -08:00
ptrace.c ARM: 7307/1: vfp: fix ptrace regset modification race 2012-02-02 17:37:42 +00:00
relocate_kernel.S ARM: 7065/1: kexec: ensure new kernel is entered in ARM state 2011-08-28 10:39:41 +01:00
return_address.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
sched_clock.c ARM: 7205/2: sched_clock: allow sched_clock to be selected at runtime 2011-12-18 23:00:26 +00:00
setup.c ARM: 7293/1: logical_cpu_map: decouple CPU mapping from SMP 2012-01-23 10:20:05 +00:00
signal.c ARM: 7306/1: vfp: flush thread hwstate before restoring context from sigframe 2012-02-02 17:37:41 +00:00
signal.h
sleep.S ARM: LPAE: add ISBs around MMU enabling code 2011-12-08 10:30:38 +00:00
smp_scu.c Merge branches 'arnd-randcfg-fixes', 'debug', 'io' (early part), 'l2x0', 'p2v', 'pgt' (early part) and 'smp' into for-linus 2011-10-25 08:19:29 +01:00
smp_tlb.c
smp_twd.c ARM: 7297/1: smp_twd: make sure timer is stopped before registering it 2012-01-23 10:20:07 +00:00
smp.c ARM: 7293/1: logical_cpu_map: decouple CPU mapping from SMP 2012-01-23 10:20:05 +00:00
stacktrace.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
suspend.c ARM: suspend: use idmap_pgd instead of suspend_pgd 2011-12-06 14:04:14 +00:00
swp_emulate.c ARM: 7208/1: Add condition code checking to SWP emulation handler. 2011-12-13 08:52:03 +00:00
sys_arm.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
sys_oabi-compat.c ARM: 6891/1: prevent heap corruption in OABI semtimedop 2011-04-29 15:53:14 +01:00
tcm.c ARM: 7199/2: only look for TCM on ARMv5 and later 2011-12-13 08:52:02 +00:00
tcm.h
thumbee.c
time.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
topology.c ARM: 7182/1: ARM cpu topology: fix warning 2011-11-30 23:55:21 +00:00
traps.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2011-10-26 16:17:32 +02:00
unwind.c ARM: unwinder: fix bisection to find origin in .idx section 2011-12-15 14:02:19 -08:00
vmlinux.lds.S ARM: 7290/1: vmlinux.lds.S: align the exception fixup table to a 4-byte boundary 2012-01-23 10:20:04 +00:00
xscale-cp0.c arm: remove several unnecessary module.h include instances 2011-10-31 19:30:48 -04:00