[PATCH] x86-64: fix unwind annotations in recent NMI changes

[PATCH] x86-64: fix unwind annotations in recent NMI changes

[Jan Beulich]

While in one case a plain annotation is necessary, in the other case
the stack adjustment can simply be folded into the immediately
preceding RESTORE_ALL, thus getting the correct annotation for free.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

---
 arch/x86/kernel/entry_64.S |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- 3.8-rc4/arch/x86/kernel/entry_64.S
+++ 3.8-rc4-x86_64-NMI-unwind/arch/x86/kernel/entry_64.S
@@ -1781,6 +1781,7 @@ first_nmi:
 	 * Leave room for the "copied" frame
 	 */
 	subq $(5*8), %rsp
+	CFI_ADJUST_CFA_OFFSET 5*8
 
 	/* Copy the stack frame to the Saved frame */
 	.rept 5
@@ -1863,10 +1864,8 @@ end_repeat_nmi:
 nmi_swapgs:
 	SWAPGS_UNSAFE_STACK
 nmi_restore:
-	RESTORE_ALL 8
-
-	/* Pop the extra iret frame */
-	addq $(5*8), %rsp
+	/* Pop the extra iret frame at once */
+	RESTORE_ALL 6*8
 
 	/* Clear the NMI executing stack variable */
 	movq $0, 5*8(%rsp)

[tip:x86/urgent] x86-64: Fix unwind annotations in recent NMI changes

[tip-bot for Jan Beulich]

Commit-ID:  444723dccc3c855fe88ea138cdec46f30e707b74
Gitweb:     http://git.kernel.org/tip/444723dccc3c855fe88ea138cdec46f30e707b74
Author:     Jan Beulich <JBeulich@suse.com>
AuthorDate: Thu, 24 Jan 2013 09:27:31 +0000
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 24 Jan 2013 10:56:32 +0100

x86-64: Fix unwind annotations in recent NMI changes

While in one case a plain annotation is necessary, in the other
case the stack adjustment can simply be folded into the
immediately preceding RESTORE_ALL, thus getting the correct
annotation for free.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexander van Heukelum <heukelum@mailshack.com>
Link: http://lkml.kernel.org/r/51010C9302000078000B9045@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/entry_64.S | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 07a7a04..cb3c591 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1781,6 +1781,7 @@ first_nmi:
 	 * Leave room for the "copied" frame
 	 */
 	subq $(5*8), %rsp
+	CFI_ADJUST_CFA_OFFSET 5*8
 
 	/* Copy the stack frame to the Saved frame */
 	.rept 5
@@ -1863,10 +1864,8 @@ end_repeat_nmi:
 nmi_swapgs:
 	SWAPGS_UNSAFE_STACK
 nmi_restore:
-	RESTORE_ALL 8
-
-	/* Pop the extra iret frame */
-	addq $(5*8), %rsp
+	/* Pop the extra iret frame at once */
+	RESTORE_ALL 6*8
 
 	/* Clear the NMI executing stack variable */
 	movq $0, 5*8(%rsp)