diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-05-15 11:02:23 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-05 23:19:59 -0700 |
| commit | 68507f74d96c86b778deb3b11c0f924e85b6b986 (patch) | |
| tree | 6a8944c624cd034990bcebd605e576e4192aeefe | |
| parent | f8db4e64c79540e36a2b7cd728a3988ac568f0a5 (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 <jistone@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 4bc816a74a2e..f2646934c714 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 asm_trace_hardirqs_on |