From: David Howells <dhowells@redhat.com>
Date: Fri, 26 Oct 2007 13:17:00 +0100
Subject: [ppc64] Make the vDSO handle C++ unwinding correctly
Message-id: 5220.1193401020@redhat.com
O-Subject: [RHEL5 PATCH] PPC64: Make the vDSO handle C++ unwinding correctly
Bugzilla: 420551

This patch makes the ppc64 vDSO handle C++ exception stack unwinding correctly
by indicating that the 32-bit CR register should be saved in the correct place
in the 64-bit slot on the stack [BZ 350291].

This fix has been tested with the test program attached to the bugzilla log.

David

diff --git a/arch/powerpc/kernel/vdso64/sigtramp.S b/arch/powerpc/kernel/vdso64/sigtramp.S
index 17a83fa..59eb59b 100644
--- a/arch/powerpc/kernel/vdso64/sigtramp.S
+++ b/arch/powerpc/kernel/vdso64/sigtramp.S
@@ -134,13 +134,16 @@ V_FUNCTION_END(__kernel_sigtramp_rt64)
 9:
 
 /* This is where the pt_regs pointer can be found on the stack.  */
-#define PTREGS 128+168+56
+#define PTREGS	128+168+56
 
 /* Size of regs.  */
-#define RSIZE 8
+#define RSIZE	8
+
+/* Size of CR reg in DWARF unwind info. */
+#define CRSIZE	4
 
 /* This is the offset of the VMX reg pointer.  */
-#define VREGS 48*RSIZE+33*8
+#define VREGS	48*RSIZE+33*8
 
 /* Describe where general purpose regs are saved.  */
 #define EH_FRAME_GEN \
@@ -178,7 +181,7 @@ V_FUNCTION_END(__kernel_sigtramp_rt64)
   rsave (31, 31*RSIZE);							\
   rsave (67, 32*RSIZE);		/* ap, used as temp for nip */		\
   rsave (65, 36*RSIZE);		/* lr */				\
-  rsave (70, 38*RSIZE)		/* cr */
+  rsave (70, 38*RSIZE + (RSIZE - CRSIZE)) /* cr */
 
 /* Describe where the FP regs are saved.  */
 #define EH_FRAME_FP \