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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-24 11:53:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-24 11:53:13 -0700 |
| commit | a4306434b79ffc859e5dc6ab0f305a3d8204ef46 (patch) | |
| tree | d498a3e807b2d5e2920465dbf9138606c43ba9b7 /arch/arm/kernel | |
| parent | a30282478271ea8e06d424f96c1537094b309c7c (diff) | |
| parent | a2048e34d4655c06d31400646ae495bbfeb16b27 (diff) | |
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull address-limit checking fixes from Ingo Molnar:
"This fixes a number of bugs in the address-limit (USER_DS) checks that
got introduced in the merge window, (mostly) affecting the ARM and
ARM64 platforms"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
arm64/syscalls: Move address limit check in loop
arm/syscalls: Optimize address limit check
Revert "arm/syscalls: Check address limit on user-mode return"
syscalls: Use CHECK_DATA_CORRUPTION for addr_limit_user_check
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 20 | ||||
| -rw-r--r-- | arch/arm/kernel/signal.c | 10 |
2 files changed, 19 insertions, 11 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index ca3614dc6938..99c908226065 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -12,6 +12,7 @@ #include <asm/unistd.h> #include <asm/ftrace.h> #include <asm/unwind.h> +#include <asm/memory.h> #ifdef CONFIG_AEABI #include <asm/unistd-oabi.h> #endif @@ -48,12 +49,14 @@ ret_fast_syscall: UNWIND(.fnstart ) UNWIND(.cantunwind ) disable_irq_notrace @ disable interrupts + ldr r2, [tsk, #TI_ADDR_LIMIT] + cmp r2, #TASK_SIZE + blne addr_limit_check_failed ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing - tst r1, #_TIF_SYSCALL_WORK - bne fast_work_pending - tst r1, #_TIF_WORK_MASK + tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK bne fast_work_pending + /* perform architecture specific actions before user return */ arch_ret_to_user r1, lr @@ -76,16 +79,16 @@ ret_fast_syscall: UNWIND(.cantunwind ) str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 disable_irq_notrace @ disable interrupts + ldr r2, [tsk, #TI_ADDR_LIMIT] + cmp r2, #TASK_SIZE + blne addr_limit_check_failed ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing - tst r1, #_TIF_SYSCALL_WORK - bne fast_work_pending - tst r1, #_TIF_WORK_MASK + tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK beq no_work_pending UNWIND(.fnend ) ENDPROC(ret_fast_syscall) /* Slower path - fall through to work_pending */ -fast_work_pending: #endif tst r1, #_TIF_SYSCALL_WORK @@ -111,6 +114,9 @@ ENTRY(ret_to_user) ret_slow_syscall: disable_irq_notrace @ disable interrupts ENTRY(ret_to_user_from_irq) + ldr r2, [tsk, #TI_ADDR_LIMIT] + cmp r2, #TASK_SIZE + blne addr_limit_check_failed ldr r1, [tsk, #TI_FLAGS] tst r1, #_TIF_WORK_MASK bne slow_work_pending diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index e2de50bf8742..b67ae12503f3 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -614,10 +614,6 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) * Update the trace code with the current status. */ trace_hardirqs_off(); - - /* Check valid user FS if needed */ - addr_limit_user_check(); - do { if (likely(thread_flags & _TIF_NEED_RESCHED)) { schedule(); @@ -678,3 +674,9 @@ struct page *get_signal_page(void) return page; } + +/* Defer to generic check */ +asmlinkage void addr_limit_check_failed(void) +{ + addr_limit_user_check(); +} |