linux/arch/arm/kernel
Will Deacon 2af276dfb1 ARM: 7306/1: vfp: flush thread hwstate before restoring context from sigframe
Following execution of a signal handler, we currently restore the VFP
context from the ucontext in the signal frame. This involves copying
from the user stack into the current thread's vfp_hard_struct and then
flushing the new data out to the hardware registers.

This is problematic when using a preemptible kernel because we could be
context switched whilst updating the vfp_hard_struct. If the current
thread has made use of VFP since the last context switch, the VFP
notifier will copy from the hardware registers into the vfp_hard_struct,
overwriting any data that had been partially copied by the signal code.

Disabling preemption across copy_from_user calls is a terrible idea, so
instead we move the VFP thread flush *before* we update the
vfp_hard_struct. Since the flushing is performed lazily, this has the
effect of disabling VFP and clearing the CPU's VFP state pointer,
therefore preventing the thread from being updated with stale data on
the next context switch.

Cc: stable <stable@vger.kernel.org>
Tested-by: Peter Maydell <peter.maydell@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 17:37:41 +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 ARM: deprecate support for old way to pass kernel parameters 2010-07-07 16:38:36 +02:00
compat.h ARM: deprecate support for old way to pass kernel parameters 2010-07-07 16:38:36 +02:00
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 ARM: Convert VFP/Crunch/XscaleCP thread_release() to exit_thread() 2009-12-18 14:53:41 +00:00
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 ARM: dma-isa: request cascade channel after registering it 2009-12-24 18:34:08 +00:00
dma.c locking, ARM: Annotate low level hw locks as raw 2011-09-13 11:12:14 +02:00
early_printk.c ARM: Add an earlyprintk debug console 2009-12-09 10:02:18 +00:00
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 ARM: ftrace: graph tracer + dynamic ftrace 2010-11-19 21:43:27 +05:30
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 sysctl: Drop & in front of every proc_handler. 2009-11-18 08:37:40 -08:00
iwmmxt.S ARM: pxa: fix logic error in PJ4 iWMMXt handling 2011-08-11 10:10:26 +08:00
kgdb.c kgdb,arm: fix register dump 2010-10-29 13:14:40 -05:00
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 Kernel: Audit Support For The ARM Platform 2012-01-17 16:17:01 -05:00
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 ARM: Fix signal restart issues with NX and OABI compat 2009-10-25 15:39:37 +00:00
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 ARM: SMP: split out software TLB maintainence broadcasting 2010-12-20 15:09:17 +00:00
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