Commit 64284a9f authored Jul 06, 2012 by Will Deacon Committed by Russell King Jul 09, 2012

ARM: 7454/1: entry: don't bother with syscall tracing on ret_from_fork path

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.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 8f827a14

arch/arm/kernel/entry-common.S

+0 −6

Original line number	Diff line number	Diff line
		@@ -95,13 +95,7 @@ ENDPROC(ret_to_user)
		ENTRY(ret_from_fork)
		bl schedule_tail
		get_thread_info tsk
		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
		b ret_slow_syscall
		ENDPROC(ret_from_fork)