From: ebiederm@xmission.com (Eric W. Biederman)
To: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
hch@infradead.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH RESEND v3 6/6] powerpc/signal: Use unsafe_copy_siginfo_to_user()
Date: Mon, 13 Sep 2021 10:57:37 -0500 [thread overview]
Message-ID: <87h7eopixa.fsf@disp2133> (raw)
In-Reply-To: <2b179deba4fd4ec0868cdc48a0230dfa3aa5a22f.1631537060.git.christophe.leroy@csgroup.eu> (Christophe Leroy's message of "Mon, 13 Sep 2021 17:19:10 +0200")
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.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> 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?
Otherwise this change looks much cleaner.
Eric
>
> @@ -779,15 +779,13 @@ 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);
> + unsafe_copy_siginfo_to_user32(&frame->info, &ksig->info, failed);
>
> /* 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))
> - goto badframe;
> -
> regs->link = tramp;
>
> #ifdef CONFIG_PPC_FPU_REGS
> diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
> index d80ff83cacb9..56c0c74aa28c 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;
next prev parent reply other threads:[~2021-09-13 15:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 15:19 [PATCH RESEND v3 1/6] powerpc/signal64: Access function descriptor with user access block Christophe Leroy
2021-09-13 15:19 ` [PATCH RESEND v3 2/6] powerpc/signal: Include the new stack frame inside the " Christophe Leroy
2021-09-13 15:19 ` [PATCH RESEND v3 3/6] signal: Add unsafe_copy_siginfo_to_user() Christophe Leroy
2021-09-13 15:19 ` [PATCH RESEND v3 4/6] signal: Add unsafe_copy_siginfo_to_user32() Christophe Leroy
2021-09-13 15:54 ` Eric W. Biederman
2021-09-13 17:01 ` Christophe Leroy
2021-09-13 15:19 ` [PATCH RESEND v3 5/6] powerpc/uaccess: Add unsafe_clear_user() Christophe Leroy
2021-09-13 15:19 ` [PATCH RESEND v3 6/6] powerpc/signal: Use unsafe_copy_siginfo_to_user() Christophe Leroy
2021-09-13 15:57 ` Eric W. Biederman [this message]
2021-09-13 16:21 ` Eric W. Biederman
2021-09-13 17:19 ` Christophe Leroy
2021-09-13 19:11 ` Eric W. Biederman
2021-09-14 14:00 ` Christophe Leroy
2021-09-13 17:14 ` Christophe Leroy
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