Messages in this thread | | | Subject | Re: [PATCH v2 5/5] powerpc/signal: Use unsafe_copy_siginfo_to_user() | From | Christophe Leroy <> | Date | Fri, 3 Sep 2021 10:53:49 +0200 |
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Le 02/09/2021 à 20:38, Eric W. Biederman a écrit : > Christophe Leroy <christophe.leroy@csgroup.eu> 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. > > Nacked-by: "Eric W. Biederman" <ebiederm@xmission.com> > > copy_siginfo_to_user is not the same as copy_siginfo_to_user32. > > As in this patch breaks 32bit userspace on powerpc.
I don't understand your comment. As you can see below, copy_siginfo_to_user32() is used in the compat case (ie 32 bit userspace on PPC64) and unsafe_copy_siginfo_to_user() is used on the non-compat case (ie 32 bit userspace on PPC32).
So what's the issue really ?
> > >> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> >> --- >> arch/powerpc/kernel/signal_32.c | 13 ++++++------- >> arch/powerpc/kernel/signal_64.c | 5 +---- >> 2 files changed, 7 insertions(+), 11 deletions(-) >> >> diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c >> index ff101e2b3bab..f9e16d108bc8 100644 >> --- a/arch/powerpc/kernel/signal_32.c >> +++ b/arch/powerpc/kernel/signal_32.c >> @@ -710,12 +710,6 @@ static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *s >> } >> #endif >> >> -#ifdef CONFIG_PPC64 >> - >> -#define copy_siginfo_to_user copy_siginfo_to_user32 >> - >> -#endif /* CONFIG_PPC64 */ >> - >> /* >> * Set up a signal frame for a "real-time" signal handler >> * (one which gets siginfo). >> @@ -779,14 +773,19 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, >> asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); >> } >> unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed); >> +#ifndef CONFIG_COMPAT >> + unsafe_copy_siginfo_to_user(&frame->info, &ksig->info, failed); >> +#endif >> >> /* create a stack frame for the caller of the handler */ >> unsafe_put_user(regs->gpr[1], newsp, failed); >> >> user_access_end(); >> >> - if (copy_siginfo_to_user(&frame->info, &ksig->info)) >> +#ifdef CONFIG_COMPAT >> + if (copy_siginfo_to_user32(&frame->info, &ksig->info)) >> goto badframe; >> +#endif >> >> regs->link = tramp; >> >> diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c >> index 2cca6c8febe1..82b73fbd937d 100644 >> --- a/arch/powerpc/kernel/signal_64.c >> +++ b/arch/powerpc/kernel/signal_64.c >> @@ -901,15 +901,12 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, >> } >> >> unsafe_copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set), badframe_block); >> + unsafe_copy_siginfo_to_user(&frame->info, &ksig->info, badframe_block); >> /* Allocate a dummy caller frame for the signal handler. */ >> unsafe_put_user(regs->gpr[1], newsp, badframe_block); >> >> user_write_access_end(); >> >> - /* Save the siginfo outside of the unsafe block. */ >> - if (copy_siginfo_to_user(&frame->info, &ksig->info)) >> - goto badframe; >> - >> /* Make sure signal handler doesn't get spurious FP exceptions */ >> tsk->thread.fp_state.fpscr = 0;
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