From: Oleg Nesterov <oleg@redhat.com>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
Peter Zijlstra <peterz@infradead.org>,
clang-built-linux@googlegroups.com,
Linus Torvalds <torvalds@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Andy Lutomirski <luto@kernel.org>,
Sami Tolvanen <samitolvanen@google.com>,
Marco Elver <elver@google.com>, Brian Gerst <brgerst@gmail.com>,
Arnd Bergmann <arnd@arndb.de>,
Andrew Morton <akpm@linux-foundation.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] x86: signal: move save_altstack_ex out of generic headers
Date: Sat, 4 Apr 2020 18:01:00 +0200 [thread overview]
Message-ID: <20200404160100.GB26298@redhat.com> (raw)
In-Reply-To: <20200403231611.81444-1-ndesaulniers@google.com>
On 04/03, Nick Desaulniers wrote:
>
> --- a/arch/x86/kernel/signal.c
> +++ b/arch/x86/kernel/signal.c
> @@ -416,6 +416,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
> return 0;
> Efault:
> user_access_end();
> + reset_altstack();
> return -EFAULT;
> }
> #else /* !CONFIG_X86_32 */
> @@ -507,6 +508,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
>
> Efault:
> user_access_end();
> + reset_altstack();
> return -EFAULT;
> }
I must have missed something, but this looks just wrong.
reset_altstack() should be called when __setup_rt_frame() (and
unsafe_save_altstack() in particular) succeeds, not when it fails.
Nevermind, Al has already suggested to use signal_delivered()...
Oleg.
next prev parent reply other threads:[~2020-04-04 16:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 22:08 [PATCH] x86: signal: move save_altstack_ex out of generic headers Nick Desaulniers
2020-04-03 23:16 ` [PATCH v2] " Nick Desaulniers
2020-04-03 23:39 ` Al Viro
2020-04-04 16:01 ` Oleg Nesterov [this message]
2020-04-04 17:06 ` Al Viro
2020-04-04 17:31 ` Linus Torvalds
2020-04-04 17:50 ` Oleg Nesterov
2020-04-04 22:50 ` Nathan Chancellor
2020-04-13 19:12 ` Nick Desaulniers
2020-06-26 18:18 ` Nick Desaulniers
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