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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-24 11:53:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-24 11:53:13 -0700
commita4306434b79ffc859e5dc6ab0f305a3d8204ef46 (patch)
treed498a3e807b2d5e2920465dbf9138606c43ba9b7 /arch/arm/kernel/entry-common.S
parenta30282478271ea8e06d424f96c1537094b309c7c (diff)
parenta2048e34d4655c06d31400646ae495bbfeb16b27 (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/entry-common.S')
-rw-r--r--arch/arm/kernel/entry-common.S20
1 files changed, 13 insertions, 7 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