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>

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 4afed88..10911c9 100644 (file)
--- a/arch/arm/kernel/entry-common.S
+++ b/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)