i386: Add unwind directives to syscall ptregs stubs

When these stubs are actual functions (i.e. having a return
instruction) and have stack manipulation instructions in them,
they should also be annotated to allow unwinding through them.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
LKML-Reference: <4C7FBCF00200007800013F99@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 4 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 227d00920d2f..d9b950ee5590 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -750,14 +750,18 @@ ptregs_##name: \
 #define PTREGSCALL3(name) \
         ALIGN; \
 ptregs_##name: \
+        CFI_STARTPROC; \
         leal 4(%esp),%eax; \
-        pushl %eax; \
+        pushl_cfi %eax; \
         movl PT_EDX(%eax),%ecx; \
         movl PT_ECX(%eax),%edx; \
         movl PT_EBX(%eax),%eax; \
         call sys_##name; \
         addl $4,%esp; \
-        ret
+        CFI_ADJUST_CFA_OFFSET -4; \
+        ret; \
+        CFI_ENDPROC; \
+ENDPROC(ptregs_##name)
 
 PTREGSCALL1(iopl)
 PTREGSCALL0(fork)
@@ -772,15 +776,19 @@ PTREGSCALL1(vm86old)
 /* Clone is an oddball.  The 4th arg is in %edi */
         ALIGN;
 ptregs_clone:
+        CFI_STARTPROC
         leal 4(%esp),%eax
-        pushl %eax
-        pushl PT_EDI(%eax)
+        pushl_cfi %eax
+        pushl_cfi PT_EDI(%eax)
         movl PT_EDX(%eax),%ecx
         movl PT_ECX(%eax),%edx
         movl PT_EBX(%eax),%eax
         call sys_clone
         addl $8,%esp
+        CFI_ADJUST_CFA_OFFSET -8
         ret
+        CFI_ENDPROC
+ENDPROC(ptregs_clone)
 
 .macro FIXUP_ESPFIX_STACK
 /*