From: Al Viro <viro@zeniv.linux.org.uk>
To: linux-riscv@lists.infradead.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] riscv: fix a nasty sigreturn bug...
Date: Fri, 2 Sep 2022 01:13:46 +0100 [thread overview]
Message-ID: <YxFKuhw9ZGB8f/Ne@ZenIV> (raw)
In-Reply-To: <YU0wDzeS/jXwkAca@zeniv-ca.linux.org.uk>
Ping? Does anybody have objections? AFAICS, the bug is still
there...
On Fri, Sep 24, 2021 at 01:55:27AM +0000, Al Viro wrote:
> riscv has an equivalent of arm bug fixed by 653d48b22166; if signal
> gets caught by an interrupt that hits when we have the right value
> in a0 (-513), *and* another signal gets delivered upon sigreturn()
> (e.g. included into the blocked mask for the first signal and posted
> while the handler had been running), the syscall restart logics will
> see regs->cause equal to EXC_SYSCALL (we are in a syscall, after all)
> and a0 already restored to its original value (-513, which happens to
> be -ERESTARTNOINTR) and assume that we need to apply the usual
> syscall restart logics.
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
> diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
> index c2d5ecbe55264..f8fb85dc94b7a 100644
> --- a/arch/riscv/kernel/signal.c
> +++ b/arch/riscv/kernel/signal.c
> @@ -121,6 +121,8 @@ SYSCALL_DEFINE0(rt_sigreturn)
> if (restore_altstack(&frame->uc.uc_stack))
> goto badframe;
>
> + regs->cause = -1UL;
> +
> return regs->a0;
>
> badframe:
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2022-09-02 0:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-24 1:55 [PATCH] riscv: fix a nasty sigreturn bug Al Viro
2022-09-02 0:13 ` Al Viro [this message]
2022-09-02 9:22 ` Andrew Jones
2022-09-02 17:59 ` Al Viro
2022-09-15 18:48 ` Palmer Dabbelt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YxFKuhw9ZGB8f/Ne@ZenIV \
--to=viro@zeniv.linux.org.uk \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox