From: Paolo Bonzini <pbonzini@redhat.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>, "Greg Kurz" <groug@kaod.org>
Cc: qemu-devel@nongnu.org, "Alex Bennée" <alex.bennee@linaro.org>,
"Richard Henderson" <richard.henderson@linaro.org>
Subject: Re: [PATCH v2 1/2] util/log: Derive thread id from getpid() on hosts w/o gettid() syscall
Date: Thu, 20 Oct 2022 12:39:41 +0200 [thread overview]
Message-ID: <e5d785bb-3865-75a3-f1aa-c99acf127c5f@redhat.com> (raw)
In-Reply-To: <Y1AeglCfb6SHaf4N@redhat.com>
On 10/19/22 17:57, Daniel P. Berrangé wrote:
>> + if (my_id == -1) {
>> + my_id = getpid() + qatomic_fetch_inc(&counter);
>> + }
>> + return my_id;
> This doesn't look safe for linux-user when we fork, but don't exec.
Linux-user won't ever get here, however bsd-user might. We should have
get_thread_id() somewhere in util/, for example
https://github.com/wine-mirror/wine/blob/master/dlls/ntdll/unix/server.c
> The getpid() will change after the fork, but counter won't be
> reset, so a thread in the parent could clash with a thread
> in the forked child.
It might clash even if the counter is reset for that matter.
Paolo
next prev parent reply other threads:[~2022-10-20 11:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-19 15:16 [PATCH v2 0/2] util/log: Always send errors to logfile when daemonized Greg Kurz
2022-10-19 15:16 ` [PATCH v2 1/2] util/log: Derive thread id from getpid() on hosts w/o gettid() syscall Greg Kurz
2022-10-19 15:57 ` Daniel P. Berrangé
2022-10-20 8:40 ` Greg Kurz
2022-10-20 10:39 ` Paolo Bonzini [this message]
2022-10-21 14:08 ` Greg Kurz
2022-10-19 15:16 ` [PATCH v2 2/2] util/log: Always send errors to logfile when daemonized Greg Kurz
2022-10-20 2:21 ` Richard Henderson
2022-10-20 9:49 ` Greg Kurz
2022-10-20 9:58 ` Daniel P. Berrangé
2022-10-20 10:52 ` Paolo Bonzini
2022-10-24 9:44 ` Alex Bennée
2022-10-25 8:52 ` Greg Kurz
2022-10-25 9:20 ` Paolo Bonzini
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