linux-kernel - Re: [GIT PULL] timer fixes

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Date:   Sat, 13 Aug 2022 18:25:01 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Ingo Molnar <mingo@...nel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     linux-kernel@...r.kernel.org,
        Peter Zijlstra <peterz@...radead.org>, x86-ml <x86@...nel.org>
Subject: Re: [GIT PULL] timer fixes

Might wanna hold off on pulling that:

On Sat, Aug 13, 2022 at 12:25:51PM +0200, Ingo Molnar wrote:
> Linus,
> 
> Please pull the latest timers/urgent git tree from:
> 
>    git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-urgent-2022-08-13
> 
>    # HEAD: e362359ace6f87c201531872486ff295df306d13 posix-cpu-timers: Cleanup CPU timers before freeing them during exec

...

> Thadeu Lima de Souza Cascardo (1):
>       posix-cpu-timers: Cleanup CPU timers before freeing them during exec

...

> diff --git a/fs/exec.c b/fs/exec.c
> index 5fd73915c62c..f793221f4eb6 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -1304,6 +1304,9 @@ int begin_new_exec(struct linux_binprm * bprm)
>  	bprm->mm = NULL;
>  
>  #ifdef CONFIG_POSIX_TIMERS
> +	spin_lock_irq(&me->sighand->siglock);
> +	posix_cpu_timers_exit(me);
> +	spin_unlock_irq(&me->sighand->siglock);

sparse is not happy about this:

https://lore.kernel.org/r/202208140040.MMi4z6Ek-lkp@intel.com

That task_struct.sighand is marked __rcu and thus noderef and sparse
complains:

fs/exec.c:1307:26: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct spinlock [usertype] *lock
+@@     got struct spinlock [noderef] __rcu * @@

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette