From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F6F41F5821 for ; Sat, 4 Jul 2026 17:09:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783184994; cv=none; b=MS33H4w8dM3Hcv30Iw9cMBgz/nSufuDPW2RlmudLU53el+BIfi08K+Oui+KZpOHL2F8meQ1oqh9Ohnfqlz4bkkR7AeM9RPBesDjmuTwDJ4/TILpr3Gz34ER7a8HH+nDwsy9K3gfSLpNt7/hxWv5oZdzNCnWmUxRMYN1QT3iH/Jk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783184994; c=relaxed/simple; bh=d4qAg+v1egeyCFSHvUzTQBPnMpz03X05c4/GYxEOT9M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ULQ47vi5K+YHJU08Sk3RuCga8q3AFlD416bKah0yyiOgxfFGvIph/UQhD/3OA/izx1it9OEzUn3eoHYe1lPQHUvNBpFaX83ihCqa2dHP/bW5+fTDlOiA/kI6OfZlvHBeywWcnaDvBMM8vj37hNOgjjIkq3Ry47ixMZK/ctEf17Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Qn9Hqnxy; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Qn9Hqnxy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783184992; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+7i2ffzD3cMjSmqweogI23q7uPkzhas41N2XEaF5jWc=; b=Qn9HqnxybhSfxhmkW1I4rD/ue2S/xXfZiX0+2bl9cNbhNea2HZdkENg0Z8kbE5bfbepxGG vnbPW3GdfnVkT+hnHzjGWM3MrCEyFhPM5HqwpJO6KJph22AS/17Uj+//cEIHmQxNIMZyFH lC+h4BxvnVm+HiIMbiEW9uE09zOzD9w= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-343-d4jfOdRSM2a4EAxo828H2g-1; Sat, 04 Jul 2026 13:09:46 -0400 X-MC-Unique: d4jfOdRSM2a4EAxo828H2g-1 X-Mimecast-MFC-AGG-ID: d4jfOdRSM2a4EAxo828H2g_1783184985 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CDDD2195608F; Sat, 4 Jul 2026 17:09:44 +0000 (UTC) Received: from fedora (unknown [10.44.32.112]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 5ECC036F2E; Sat, 4 Jul 2026 17:09:40 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sat, 4 Jul 2026 19:09:44 +0200 (CEST) Date: Sat, 4 Jul 2026 19:09:39 +0200 From: Oleg Nesterov To: Bradley Morgan Cc: anna-maria@linutronix.de, frederic@kernel.org, jwlee2217@gmail.com, linux-kernel@vger.kernel.org, peterz@infradead.org, qw3rtyp0@gmail.com, tglx@linutronix.de Subject: Re: [PATCH] posix-cpu-timers: don't abuse lock_task_sighand() in handle_posix_cpu_timers() Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 On 07/04, Oleg Nesterov wrote: > > Hi Bradley, > > FYI, this is another private message. Damn ;) FYI, it wasn't private. I've pressed 'g' by mistake. Oleg. > On 07/04, Bradley Morgan wrote: > > > > hi oleg! I'm new to reviewing, so feel free to criticize. > > This is fine... > > But if you want to have a "real" practice, you can try to review V2 from Eric: > > [PATCH v2 00/14] Short circuit delivery for coredump signals > https://lore.kernel.org/all/877bnb4uyw.fsf_-_@email.froward.int.ebiederm.org/ > > I won't be able to take a look until the middle of the next week. > > > Would a WARN_ON_ONCE(tsk != current) be worth adding? > > See my reply on lkml. But since this message is private... > > IOW. tsk->sighand must be stable here or we have more problems. Without this > patch the "if (!lock_task_sighand(tsk, &flags))" check looks as if we can handle > the case were ->sighand is not stable, but this is not true. > > And. This patch is trivial, but it connects to other (under discussion, nontrivial) > changes related to the wrong usage of lock_task_sighand() in posix-cpu-timers.c. > > > For this patch, > > > > Reviewed-by: Bradley Morgan > > Thanks again, > > Oleg.