From: Michael Ellerman <mpe@ellerman.id.au>
To: <linuxppc-dev@ozlabs.org>
Subject: [PATCH] powerpc/kernel: Make syscall_exit a local label
Date: Fri, 5 Dec 2014 21:16:59 +1100 [thread overview]
Message-ID: <1417774619-30858-1-git-send-email-mpe@ellerman.id.au> (raw)
Currently when we back trace something that is in a syscall we see
something like this:
[c000000000000000] [c000000000000000] SyS_read+0x6c/0x110
[c000000000000000] [c000000000000000] syscall_exit+0x0/0x98
Although it's entirely correct, seeing syscall_exit at the bottom can be
confusing - we were exiting from a syscall and then called SyS_read() ?
If we instead change syscall_exit to be a local label we get something
more intuitive:
[c0000001fa46fde0] [c00000000026719c] SyS_read+0x6c/0x110
[c0000001fa46fe30] [c000000000009264] system_call+0x38/0xd0
ie. we were handling a system call, and it was SyS_read().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/kernel/entry_64.S | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 0905c8da90f1..d8828e50dbef 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -178,7 +178,7 @@ system_call: /* label this so stack traces look sane */
mtctr r12
bctrl /* Call handler */
-syscall_exit:
+.Lsyscall_exit:
std r3,RESULT(r1)
#ifdef SHOW_SYSCALLS
bl do_show_syscall_exit
@@ -270,7 +270,7 @@ syscall_dotrace:
syscall_enosys:
li r3,-ENOSYS
- b syscall_exit
+ b .Lsyscall_exit
syscall_exit_work:
#ifdef CONFIG_PPC_BOOK3S
@@ -347,33 +347,33 @@ _GLOBAL(save_nvgprs)
_GLOBAL(ppc_fork)
bl save_nvgprs
bl sys_fork
- b syscall_exit
+ b .Lsyscall_exit
_GLOBAL(ppc_vfork)
bl save_nvgprs
bl sys_vfork
- b syscall_exit
+ b .Lsyscall_exit
_GLOBAL(ppc_clone)
bl save_nvgprs
bl sys_clone
- b syscall_exit
+ b .Lsyscall_exit
_GLOBAL(ppc32_swapcontext)
bl save_nvgprs
bl compat_sys_swapcontext
- b syscall_exit
+ b .Lsyscall_exit
_GLOBAL(ppc64_swapcontext)
bl save_nvgprs
bl sys_swapcontext
- b syscall_exit
+ b .Lsyscall_exit
_GLOBAL(ret_from_fork)
bl schedule_tail
REST_NVGPRS(r1)
li r3,0
- b syscall_exit
+ b .Lsyscall_exit
_GLOBAL(ret_from_kernel_thread)
bl schedule_tail
@@ -385,7 +385,7 @@ _GLOBAL(ret_from_kernel_thread)
#endif
blrl
li r3,0
- b syscall_exit
+ b .Lsyscall_exit
/*
* This routine switches between two different tasks. The process
--
1.9.1
next reply other threads:[~2014-12-05 10:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-05 10:16 Michael Ellerman [this message]
2014-12-05 10:27 ` [PATCH] powerpc/kernel: Make syscall_exit a local label David Laight
2014-12-15 3:03 ` Michael Ellerman
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