Re: [PATCH RESEND v3 6/6] powerpc/signal: Use unsafe_copy_siginfo_to_user()

[Christophe Leroy]

Le 13/09/2021 à 17:57, Eric W. Biederman a écrit :
> Christophe Leroy <christophe.leroy@xxxxxxxxxx> writes:
>
> > Use unsafe_copy_siginfo_to_user() in order to do the copy
> > within the user access block.
> >
> > On an mpc 8321 (book3s/32) the improvment is about 5% on a process
> > sending a signal to itself.
> >
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > ---
> > v3: Don't leave compat aside, use the new unsafe_copy_siginfo_to_user32()
> > ---
> >   arch/powerpc/kernel/signal_32.c | 8 +++-----
> >   arch/powerpc/kernel/signal_64.c | 5 +----
> >   2 files changed, 4 insertions(+), 9 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
> > index ff101e2b3bab..3a2db8af2d65 100644
> > --- a/arch/powerpc/kernel/signal_32.c
> > +++ b/arch/powerpc/kernel/signal_32.c
> > @@ -710,9 +710,9 @@ static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *s
> >   }
> >   #endif
> >   
> > -#ifdef CONFIG_PPC64
> > +#ifndef CONFIG_PPC64
> >   
> > -#define copy_siginfo_to_user	copy_siginfo_to_user32
> > +#define unsafe_copy_siginfo_to_user32	unsafe_copy_siginfo_to_user
> >   
> >   #endif /* CONFIG_PPC64 */
>
> Any particular reason to reverse the sense of this #ifdef?

Yes I had double definition of unsafe_copy_siginfo_to_user(), I could 
have ifdefed out unsafe_copy_siginfo_to_user() in signal.h, but I 
prefered to ifdef out copy_siginfo_to_user32() in compat.h

> Otherwise this change looks much cleaner.

Thanks
Christophe