[PATCH v3 2/4] ARM: entry: don't bother with syscall tracing on ret_from_fork path
will.deacon at arm.com
Fri Jun 15 11:58:05 EDT 2012
ret_from_fork is setup for a freshly spawned child task via copy_thread,
called from copy_process. The latter function clears TIF_SYSCALL_TRACE
and also resets the child task's audit_context to NULL, meaning that
there is little point invoking the system call tracing routines.
Furthermore, getting hold of the syscall number is a complete pain and
it looks like the current code doesn't even bother.
This patch removes the syscall tracing checks from ret_from_fork.
Signed-off-by: Will Deacon <will.deacon at arm.com>
arch/arm/kernel/entry-common.S | 6 ------
1 files changed, 0 insertions(+), 6 deletions(-)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 4afed88..10911c9 100644
@@ -95,13 +95,7 @@ ENDPROC(ret_to_user)
- ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
mov why, #1
- tst r1, #_TIF_SYSCALL_WORK @ are we tracing syscalls?
- beq ret_slow_syscall
- mov r1, sp
- mov r0, #1 @ trace exit [IP = 1]
- bl syscall_trace
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