Re: [PATCH v3 3/3] powerpc/module64: Use symbolic instructions names.

[Christophe Leroy]

Le 08/07/2019 Ã 02:56, Michael Ellerman a ÃcritÂ:
> Christophe Leroy <christophe.leroy@xxxxxx> writes:
> > To increase readability/maintainability, replace hard coded
> > instructions values by symbolic names.
> >
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
> > ---
> > v3: fixed warning by adding () in an 'if' around X | Y (unlike said in v2 history, this change was forgotten in v2)
> > v2: rearranged comments
> >
> >   arch/powerpc/kernel/module_64.c | 53 +++++++++++++++++++++++++++--------------
> >   1 file changed, 35 insertions(+), 18 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
> > index c2e1b06253b8..b33a5d5e2d35 100644
> > --- a/arch/powerpc/kernel/module_64.c
> > +++ b/arch/powerpc/kernel/module_64.c
> > @@ -704,18 +711,21 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
> ...
> >   			/*
> >   			 * If found, replace it with:
> >   			 *	addis r2, r12, (.TOC.-func)@ha
> >   			 *	addi r2, r12, (.TOC.-func)@l
> >   			 */
> > -			((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value);
> > -			((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
> > +			((uint32_t *)location)[0] = PPC_INST_ADDIS | __PPC_RT(R2) |
> > +						    __PPC_RA(R12) | PPC_HA(value);
> > +			((uint32_t *)location)[1] = PPC_INST_ADDI | __PPC_RT(R2) |
> > +						    __PPC_RA(R12) | PPC_LO(value);
> >   			break;
>
> This was crashing and it's amazing how long you can stare at a
> disassembly and not see the difference between `r2` and `r12` :)

Argh, yes. I was misleaded by the comment I guess. Sorry for that and 
thanks for fixing.

Christophe

> Fixed now.
>
> cheers