From: Borislav Petkov <bp@alien8.de>
To: Jiashuo Liang <liangjs@pku.edu.cn>
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] signal/x86: Don't send SIGSEGV twice on SEGV_PKUERR
Date: Thu, 3 Jun 2021 20:37:11 +0200 [thread overview]
Message-ID: <YLkhV+lSqXlcfUc5@zn.tnic> (raw)
In-Reply-To: <20210601085203.40214-1-liangjs@pku.edu.cn>
On Tue, Jun 01, 2021 at 04:52:03PM +0800, Jiashuo Liang wrote:
> Before this patch, the __bad_area_nosemaphore function calls both
> force_sig_pkuerr and force_sig_fault when handling SEGV_PKUERR. This does
> not cause problems because the second signal is filtered by the
> legacy_queue check in __send_signal.
I'm likely missing something but the first signal gets filtered by that
same legacy_queue() check too, no?
Because both calls end up in
force_sig_info_to_task(info, current);
with the info struct populated with:
info.si_signo = SIGSEGV;
info.si_errno = 0;
info.si_code = SEGV_PKUERR;
info.si_addr = addr;
info.si_pkey = pkey;
except the second call - force_sig_fault() - doesn't put pkey in
->si_pkey.
So what's up?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-06-03 18:37 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-01 8:52 [PATCH] signal/x86: Don't send SIGSEGV twice on SEGV_PKUERR Jiashuo Liang
2021-06-02 18:42 ` Eric W. Biederman
2021-06-02 19:02 ` Borislav Petkov
2021-06-03 18:37 ` Borislav Petkov [this message]
2021-06-03 21:31 ` Eric W. Biederman
2021-06-04 13:06 ` Borislav Petkov
2021-06-04 14:33 ` Eric W. Biederman
2021-06-04 14:54 ` Borislav Petkov
2021-06-04 13:26 ` [tip: x86/urgent] x86/fault: " tip-bot2 for Jiashuo Liang
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