From: Carlos O'Donell <carlos@redhat.com>
To: musl@lists.openwall.com, Dominic Chen <d.c.ddcc@gmail.com>,
Rich Felker <dalias@libc.org>,
fweimer@redhat.com
Subject: Re: [musl] Incorrect thread TID caching
Date: Wed, 3 Feb 2021 22:28:16 -0500 [thread overview]
Message-ID: <634da58e-77d0-bea4-8ebf-f2c1fc933fee@redhat.com> (raw)
In-Reply-To: <c1944b59-e2ab-d110-b2a1-ca47b93bf521@gmail.com>
On 2/3/21 3:21 PM, Dominic Chen wrote:
> The code in question is a unittest for the sandbox, which manually
> calls clone with CLONE_NEWPID to fork a child in a PID namespace,
> then installs a signal handler and checks that it receives SIGTERM
> correctly:
> https://source.chromium.org/chromium/chromium/src/+/master:sandbox/linux/services/namespace_sandbox_unittest.cc;l=194
> . But under musl, raise() uses the cached TID value, so the test
> eventually times out.
>
> I missed that the NamespaceSandbox::ForkInNewPidNamespace() function
> does manually update the cached TID for glibc after calling the
> ForkWithFlags wrapper, so I can just do the same for musl too.
As Rich said for musl, this is not ABI for glibc either.
I'm not sure why you need to reset the TID cache. In glibc we have
containerized tests and we do not need to change internals of the
runtime e.g. unshare (CLONE_NEWUSER, CLONE_NEWPID, CLONE_NEWNS);
(see glibc/support/test-container.c).
--
Cheers,
Carlos.
next prev parent reply other threads:[~2021-02-04 3:28 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-03 4:04 Dominic Chen
2021-02-03 7:16 ` Florian Weimer
2021-02-03 19:21 ` Rich Felker
2021-02-03 20:21 ` Dominic Chen
2021-02-03 21:01 ` Rich Felker
2021-02-03 22:30 ` Dominic Chen
2021-02-03 22:55 ` Rich Felker
2021-02-15 16:56 ` Rich Felker
2021-02-17 19:49 ` Dominic Chen
2021-02-17 20:11 ` Rich Felker
2021-02-17 21:07 ` Rich Felker
2021-03-12 21:14 ` Dominic Chen
2021-02-04 3:28 ` Carlos O'Donell [this message]
2021-02-04 4:22 ` Dominic Chen
2021-02-04 16:15 ` Rich Felker
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