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Re: Bad unwinder data for __kernel_sigtramp_rt64 in PPC 64 vDSO corrupts Condition Register
Jakub Jelinek writes:
> On Tue, Oct 16, 2007 at 07:22:31PM +0100, Andrew Haley wrote:
> > > 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;
> > Won't this generate an alignment fault?
> Why? The reg size is 32-bit, so it only should be read/written
> as 32-bit value.
> E.g. a brief look at _Unwind_RaiseException shows:
> lwz 12,5656(1)
> mtcrf 32,12 #,
> ld 15,5368(1) #,
> ld 16,5376(1) #,
> mtcrf 16,12 #,
> ld 17,5384(1) #,
> ld 18,5392(1) #,
> mtcrf 8,12 #,
> so it shouldn't have any problems with 4 byte alignment (rather than 8 byte
Yes, I think it's OK.
I was thinking about uw_install_context_1, but that should be fine, as
it uses memcpy.