[tip:x86/debug] x86-64: Fix unwind annotations in syscall stubs

From: tip-bot for Jan Beulich
Date: Fri Sep 03 2010 - 03:11:48 EST


Commit-ID: e6b04b6b5a3182ae36cf9a69f1aaaee432edc8ad
Gitweb: http://git.kernel.org/tip/e6b04b6b5a3182ae36cf9a69f1aaaee432edc8ad
Author: Jan Beulich <JBeulich@xxxxxxxxxx>
AuthorDate: Thu, 2 Sep 2010 13:52:45 +0100
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 3 Sep 2010 08:14:09 +0200

x86-64: Fix unwind annotations in syscall stubs

With the return address removed from the stack, these should
really refer to their caller's register state.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Acked-by: Alexander van Heukelum <heukelum@xxxxxxxxxxx>
LKML-Reference: <4C7FBA3D0200007800013F61@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/entry_64.S | 9 ++++-----
1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 17be5ec..16aeff0 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -714,9 +714,8 @@ END(ptregscall_common)

ENTRY(stub_execve)
CFI_STARTPROC
- popq %r11
- CFI_ADJUST_CFA_OFFSET -8
- CFI_REGISTER rip, r11
+ addq $8, %rsp
+ PARTIAL_FRAME 0
SAVE_REST
FIXUP_TOP_OF_STACK %r11
movq %rsp, %rcx
@@ -735,7 +734,7 @@ END(stub_execve)
ENTRY(stub_rt_sigreturn)
CFI_STARTPROC
addq $8, %rsp
- CFI_ADJUST_CFA_OFFSET -8
+ PARTIAL_FRAME 0
SAVE_REST
movq %rsp,%rdi
FIXUP_TOP_OF_STACK %r11
@@ -1445,7 +1444,6 @@ error_swapgs:
error_sti:
TRACE_IRQS_OFF
ret
- CFI_ENDPROC

/*
* There are two places in the kernel that can potentially fault with
@@ -1470,6 +1468,7 @@ bstep_iret:
/* Fix truncated RIP */
movq %rcx,RIP+8(%rsp)
jmp error_swapgs
+ CFI_ENDPROC
END(error_entry)


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