On Wed, 2007-10-17 at 12:58 +0930, Alan Modra wrote: > On Tue, Oct 16, 2007 at 08:21:55PM +0200, Jakub Jelinek wrote: > > On Tue, Oct 16, 2007 at 06:02:13PM +0100, Andrew Haley wrote: > > > The reason is that the unwinder data for CR in the vDSO is wrong. The > > > line that affects the CR is here in > > My fault. > > > According to __builtin_init_dwarf_reg_size_table on ppc64-linux > > r0..r31, fp0..fp31, mq, lr, ctr, ap, vrsave, vscr, spe_acc, spefcsr, sfp > > are 64-bit, v0..v31 128-bit and cr0..cr7, xer 32-bit. > > So both kernel and gcc/config/rs6000/linux-unwind.h are wrong. > > > > > arch/powerpc/kernel/vdso64/sigtramp.S: > > > > > > rsave (70, 38*RSIZE) /* cr */ > > > > This should just be changed to > > /* Size of CR regs in DWARF unwind info. */ > > #define CRSIZE 4 > > ... > > rsave (70, 38*RSIZE + (RSIZE - CRSIZE)) /* cr */ > > > > and similarly linux-unwind.h should do: > > > > 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; > > This looks good to me. I don't think we can change the unwinder to > use a different size for cr as that would break unwinding through > normal stack frames that save cr.
So the kernel fix would look like that right ? If you are ok, I'll submit it tomorrow. Index: linux-work/arch/powerpc/kernel/vdso64/sigtramp.S =================================================================== --- linux-work.orig/arch/powerpc/kernel/vdso64/sigtramp.S 2007-10-17 13:32:49.000000000 +1000 +++ linux-work/arch/powerpc/kernel/vdso64/sigtramp.S 2007-10-17 13:34:18.000000000 +1000 @@ -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 \
