From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: "Dmitry V. Levin" <ldv@altlinux.org>,
"Eric W. Biederman" <ebiederm@xmission.com>
Cc: sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: sparc/ppc/arm compat siginfo ABI regressions: sending SIGFPE via kill() returns wrong values in si_pid and si_uid
Date: Thu, 12 Apr 2018 14:14:04 +0100 [thread overview]
Message-ID: <20180412131404.GE16141@n2100.armlinux.org.uk> (raw)
In-Reply-To: <20180412124928.GA29458@altlinux.org>
On Thu, Apr 12, 2018 at 03:49:28PM +0300, Dmitry V. Levin wrote:
> The "KERNEL BUG" diagnostics I was talking about was added to strace yesterday
> as a part of workaround commit, see
> https://github.com/strace/strace/commit/34c7794cc16e2511eda7b1d5767c655a83b17309
> Before that change the test just failed.
Ah, seeing the test case really helps to see exactly what and why it's
broken. Yes, Eric's commit was definitely wrong and needs to be
reverted, because it incorrectly changes what happens when kill(1) is
used to deliver a SIGFPE signal to a process.
Eric, please sort this out - you have a much better handle on whether
there are any dependencies here that would need to be resolved from
a simple revert of the offending commits, but that revert must happen
because you've caused a user visible regression.
The original code _was_ safe even if it wasn't correct to the specs,
as we'd end up copying the si_addr field (as the si_pid copy) and a
zeroed field as the si_uid copy. It was just that si_code was
technically wrong, and that's something that would be even more
dangerous to change now.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
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next prev parent reply other threads:[~2018-04-12 13:14 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-09 15:22 ppc compat v4.16 regression: sending SIGTRAP or SIGFPE via kill() returns wrong values in si_pid and si_uid Dmitry V. Levin
2018-04-12 1:34 ` sparc/ppc/arm compat siginfo ABI regressions: sending " Dmitry V. Levin
2018-04-12 1:45 ` Linus Torvalds
2018-04-12 9:58 ` Russell King - ARM Linux
2018-04-12 11:03 ` Dmitry V. Levin
2018-04-12 12:19 ` Russell King - ARM Linux
2018-04-12 12:49 ` Dmitry V. Levin
2018-04-12 13:14 ` Russell King - ARM Linux [this message]
2018-04-12 16:50 ` Linus Torvalds
2018-04-12 17:20 ` Russell King - ARM Linux
2018-04-12 17:22 ` Linus Torvalds
2018-04-13 9:42 ` Russell King - ARM Linux
2018-04-13 16:33 ` Linus Torvalds
2018-04-13 17:08 ` Dave Martin
2018-04-13 17:54 ` Russell King - ARM Linux
2018-04-13 18:23 ` Linus Torvalds
2018-04-13 18:45 ` Dave Martin
2018-04-13 19:53 ` Linus Torvalds
2018-04-15 13:12 ` Russell King - ARM Linux
2018-04-15 15:22 ` Eric W. Biederman
2018-04-15 15:56 ` [RFC PATCH 0/3] Dealing with the aliases of SI_USER Eric W. Biederman
2018-04-15 15:57 ` [RFC PATCH 1/3] signal: Ensure every siginfo we send has all bits initialized Eric W. Biederman
2018-04-17 13:23 ` Dave Martin
2018-04-17 19:37 ` Eric W. Biederman
2018-04-18 12:47 ` Dave Martin
2018-04-18 14:22 ` Eric W. Biederman
2018-04-19 8:26 ` Dave Martin
2018-04-15 15:58 ` [RFC PATCH 2/3] signal: Reduce copy_siginfo_to_user to just copy_to_user Eric W. Biederman
2018-04-15 15:59 ` [RFC PATCH 3/3] signal: Stop special casing TRAP_FIXME and FPE_FIXME in siginfo_layout Eric W. Biederman
2018-04-15 18:16 ` [RFC PATCH 0/3] Dealing with the aliases of SI_USER Linus Torvalds
2018-04-16 2:03 ` Eric W. Biederman
2018-04-18 17:58 ` Eric W. Biederman
2018-04-19 9:28 ` Dave Martin
2018-04-19 14:40 ` Eric W. Biederman
2018-04-13 18:35 ` sparc/ppc/arm compat siginfo ABI regressions: sending SIGFPE via kill() returns wrong values in si_pid and si_uid Dave Martin
2018-04-13 18:50 ` Russell King - ARM Linux
2018-04-13 18:56 ` Dave Martin
2018-04-12 17:35 ` Dmitry V. Levin
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