ARM: 7454/1: entry: don't bother with syscall tracing on ret_from_for…

…k 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>

arch/arm/kernel/entry-common.S

@@ -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)