lkml.org 
[lkml]   [2006]   [May]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [discuss] [RFC] [PATCH] Double syscall exit traces on x86_64
Date
On Friday 26 May 2006 05:24, Jeff Dike wrote:
> We are seeing double ptrace notifications of system call returns on recent
> x86_64 kernels. This breaks UML and at least one other app.

I believe this patch is the correct fix. Can you confirm it works for you?

-Andi

Don't do syscall exit tracing twice

int_ret_from_syscall already does syscall exit tracing, so
no need to do it again in the caller.

This caused problems for UML and some other special programs doing
syscall interception.

Signed-off-by: Andi Kleen <ak@suse.de>

Index: linux/arch/x86_64/kernel/entry.S
===================================================================
--- linux.orig/arch/x86_64/kernel/entry.S
+++ linux/arch/x86_64/kernel/entry.S
@@ -282,12 +282,7 @@ tracesys:
ja 1f
movq %r10,%rcx /* fixup for C */
call *sys_call_table(,%rax,8)
- movq %rax,RAX-ARGOFFSET(%rsp)
-1: SAVE_REST
- movq %rsp,%rdi
- call syscall_trace_leave
- RESTORE_TOP_OF_STACK %rbx
- RESTORE_REST
+1: movq %rax,RAX-ARGOFFSET(%rsp)
/* Use IRET because user could have changed frame */
jmp int_ret_from_sys_call
CFI_ENDPROC
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2006-05-26 12:39    [W:0.486 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site