diff options
authorRussell King <>2015-05-15 11:02:23 +0100
committerGreg Kroah-Hartman <>2015-06-06 08:19:38 -0700
commite497a5167b8324a8728dc30cb360cab2934732a1 (patch)
parent5388b9840541d379ab19527e7b7cb6a9d4db0371 (diff)
ARM: fix missing syscall trace exit
commit 1b97937246d8b97c0760d16d8992c7937bdf5e6a upstream. Josh Stone reports: I've discovered a case where both arm and arm64 will miss a ptrace syscall-exit that they should report. If the syscall is entered without TIF_SYSCALL_TRACE set, then it goes on the fast path. It's then possible to have TIF_SYSCALL_TRACE added in the middle of the syscall, but ret_fast_syscall doesn't check this flag again. Fix this by always checking for a syscall trace in the fast exit path. Reported-by: Josh Stone <> Signed-off-by: Russell King <> Signed-off-by: Greg Kroah-Hartman <>
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index a2dcafdf1bc8..98dd389e3b3c 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -32,7 +32,9 @@ ret_fast_syscall:
UNWIND(.fnstart )
UNWIND(.cantunwind )
disable_irq @ disable interrupts
- ldr r1, [tsk, #TI_FLAGS]
+ ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
+ tst r1, #_TIF_SYSCALL_WORK
+ bne __sys_trace_return
tst r1, #_TIF_WORK_MASK
bne fast_work_pending