From: "tip-bot2 for Frederic Weisbecker" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Victor Stinner <vstinner@redhat.com>,
Chris Hixon <linux-kernel-bugs@hixontech.com>,
Frederic Weisbecker <frederic@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: timers/urgent] posix-cpu-timers: Prevent spuriously armed 0-value itimer
Date: Thu, 23 Sep 2021 09:57:44 -0000 [thread overview]
Message-ID: <163239106440.25758.1989053609281702993.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20210913145332.232023-1-frederic@kernel.org>
The following commit has been merged into the timers/urgent branch of tip:
Commit-ID: 8cd9da85d2bd87ce889043e7b1735723dd10eb89
Gitweb: https://git.kernel.org/tip/8cd9da85d2bd87ce889043e7b1735723dd10eb89
Author: Frederic Weisbecker <frederic@kernel.org>
AuthorDate: Mon, 13 Sep 2021 16:53:32 +02:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 23 Sep 2021 11:53:51 +02:00
posix-cpu-timers: Prevent spuriously armed 0-value itimer
Resetting/stopping an itimer eventually leads to it being reprogrammed
with an actual "0" value. As a result the itimer expires on the next
tick, triggering an unexpected signal.
To fix this, make sure that
struct signal_struct::it[CPUCLOCK_PROF/VIRT]::expires is set to 0 when
setitimer() passes a 0 it_value, indicating that the timer must stop.
Fixes: 406dd42bd1ba ("posix-cpu-timers: Force next expiration recalc after itimer reset")
Reported-by: Victor Stinner <vstinner@redhat.com>
Reported-by: Chris Hixon <linux-kernel-bugs@hixontech.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210913145332.232023-1-frederic@kernel.org
---
kernel/time/posix-cpu-timers.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index ee73686..643d412 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -1404,7 +1404,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid,
}
}
- *newval += now;
+ if (*newval)
+ *newval += now;
}
/*
next prev parent reply other threads:[~2021-09-23 9:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 14:53 [PATCH] posix-cpu-timers: Fix spuriously armed 0-value itimer Frederic Weisbecker
2021-09-23 9:57 ` tip-bot2 for Frederic Weisbecker [this message]
2021-09-26 12:58 ` Stafford Horne
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=163239106440.25758.1989053609281702993.tip-bot2@tip-bot2 \
--to=tip-bot2@linutronix.de \
--cc=frederic@kernel.org \
--cc=linux-kernel-bugs@hixontech.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=vstinner@redhat.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).