[POWERPC] Fix 64 bits vDSO DWARF info for CR register
The current DWARF info for CR are incorrect, causing the gcc unwinder to
go to lunch if we take a segfault in the vdso. This fixes it.
Problem identified by Andrew Haley, and fix provided by Jakub Jelinek
(thanks !).
Unfortunately, a bug in gcc cause it to not quite work either, but that
is being fixed separately with something around the lines of:
linux-unwind.h:
fs->regs.reg[R_CR2].loc.offset = (long) ®s->ccr - new_cfa;
+ /* CR? regs are just 32-bit and PPC is big-endian. */
+ fs->regs.reg[R_CR2].loc.offset += sizeof (long) - 4;
(According to Jakub)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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 @@
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 @@
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 \