powerpc: Fix 64 bits vDSO dwarf info for CR register
PATCH 1/1 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 taking a segfault in the vdso. This patch 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:
Signed-off-by Benjamin Herrenschmidt <[email protected]>
---
arch/powerpc/kernel/vdso64/sigtramp.S +7 -4
@@ -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 \