From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 DC46625B0B2 for ; Sat, 4 Jul 2026 17:05:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783184733; cv=none; b=N5iG8kR40Nw5eLj4GtJJGk43e5Iu5SSSMgPMgaH7TeKabKmqVl4XHiG7lUljlTdCyBMt1W/BPiSE+OOHxQ8/sB9cwZ+7+hDOsZFZQp7t58kN28Dyc1Zw/rbyqnsH2cb9oLN/w2MRMmzJeLAfXLarF0A4iCxrB1KhgHqG9hYDGdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783184733; c=relaxed/simple; bh=gAzUt8DzBHGDUb3uJsDV5wj0KXuJKGKVeqTp2L9J3vA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Nhu5SZM1xYxLhpdH+JBZq+rMqsGdqbQR7/79MEIB0OzP5yoaMhBfMyuLGFEZf0Q0zOLuG2NVwYsoXWufeQTDJV3Ngo0NfU6PcU9+S9DhhO+BZ9QAFJwaCqTVb7gAmh3GetGcqVKiCR9rauMZYuWto4wMC02vvJljGcBuVBQi3bc= 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=V+CzKEEN; arc=none smtp.client-ip=170.10.133.124 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="V+CzKEEN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783184730; 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=iIJbdkDzlqc1f3O5w8MCpJlXINkjHFxsf9BQ86yxT5c=; b=V+CzKEEN78guny1KB6pluuA4jw+Vz6IbSWACazLjLgdO0kUitdnqNEIuAT1IWezLGsO5Ty WC0jWiJTzwNL2aCyW1x5IZKCX/QojBKbsbiuyqGyKGzekXXPDNsfWo3k7I4YAZYoDcXJUZ whbQbf22/+YUYyyYAualrKwqMTWWDs8= Received: from mx-prod-mc-05.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-440-furGmtAlP0WTFJiVop0CGQ-1; Sat, 04 Jul 2026 13:05:27 -0400 X-MC-Unique: furGmtAlP0WTFJiVop0CGQ-1 X-Mimecast-MFC-AGG-ID: furGmtAlP0WTFJiVop0CGQ_1783184726 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8AD781956094; Sat, 4 Jul 2026 17:05:25 +0000 (UTC) Received: from fedora (unknown [10.44.32.112]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id F279A18005B3; Sat, 4 Jul 2026 17:05:21 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sat, 4 Jul 2026 19:05:25 +0200 (CEST) Date: Sat, 4 Jul 2026 19:05:20 +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 3.4.1 on 10.30.177.111 Hi Bradley, FYI, this is another private message. 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.