[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) &regs->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>
This commit is contained in:
Benjamin Herrenschmidt 2007-10-17 14:26:50 +10:00 committed by Paul Mackerras
parent f66bce5e6a
commit 081c11a5d0
1 changed files with 7 additions and 4 deletions

View File

@ -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 \