Re: Bad unwinder data for __kernel_sigtramp_rt64 in PPC 64 vDSO corrupts Condition Register

[Jakub Jelinek]

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

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) &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;

        Jakub