From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Thu, 3 May 2012 18:42:58 +0100 Subject: [PATCH 4/6] ARM: entry: don't bother with syscall tracing on ret_from_fork path In-Reply-To: <1336066980-24000-1-git-send-email-will.deacon@arm.com> References: <1336066980-24000-1-git-send-email-will.deacon@arm.com> Message-ID: <1336066980-24000-5-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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 54ee265..93962cc 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -91,13 +91,7 @@ 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) -- 1.7.4.1