From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 8B7BF29A9C9; Tue, 28 Oct 2025 07:52:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761637944; cv=none; b=s2vaxRTgsMRpi18BO6DvDfu7Fkh4OFyk6oR3Zedkiecw9bMQFtI6CmfeR0z0E6QpQ/diBEMGNoeJDQQ9SG8ySsSPZcBk56ODbCjvrnNe5z7Wqec6BHGRQQBh8xH99noPwtk87kk3FTquWNpntPs9mZ1OQhPg9cfx3H0kCoHE+JM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761637944; c=relaxed/simple; bh=BlH1k/7FQlfjC1lJDoXjs5d1U9toPAOhi2tez2K7Kzg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F9FWL0fncMj852YnkqlCVnFGCfiX9PwCt6NgJiNars2LSai1Npo/1fb4rtJ/UHsPVYR5gSuWWhIGFNFmYdan5I5/PAT+RyOca/LxL4N8SHAg6aPL0rVvQtnzWhzRVssAW0Rfa55mtifvt/HPk+IBlJZAFCtMrgJ0QzOIJnnp93s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Kiu7UYNS; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=TS/rXFHh; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Kiu7UYNS"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="TS/rXFHh" Date: Tue, 28 Oct 2025 08:52:18 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1761637940; 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=OHWV/31bypuym5GRXjxOlk2qZBuAxqMswHw50rJip1Q=; b=Kiu7UYNSsTpAQpdqw2sVW2UvD1GqQshrx6wqHmt3innhVdRFyZU1pVblsbB4m5qBBfDp0W lN8MnHStEMXA3UD13GEfJx76HHjOAb1UxoalqdxptlZOEEQzkJ5rztbNUHBIObrX9VIJiD mjCm4hWNWv7+NoZ92y3/aI9bgATAD3PtkwRH7kWeYeZc4hBZbh014CPC3EyeWT09bmTh5+ +M/HUd5pqe+i5ckJVS6ZdIOMSgB0dhL7pP9Wle1TMXnBpnQ6zJBRRTwF+m0IAW9aedIu2q TwxjO6v9tS3EsRCk4jo73UAvCJojwIHplVF37X+5LJq4MFHFWIQ3FZDk4iZmiQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1761637940; 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=OHWV/31bypuym5GRXjxOlk2qZBuAxqMswHw50rJip1Q=; b=TS/rXFHhiwPMG/jXJvataZ1SJRJMP44uwocqxI6+TbbESv3cus8zaGjEMZdGKn/eRKY4dj z7oADzXFJeZWgpDw== From: Sebastian Andrzej Siewior To: Yonghong Song Cc: Sahil Chandna , syzbot+b0cff308140f79a9c4cb@syzkaller.appspotmail.com, andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, eddyz87@gmail.com, haoluo@google.com, john.fastabend@gmail.com, jolsa@kernel.org, kpsingh@kernel.org, linux-kernel@vger.kernel.org, listout@listout.xyz, martin.lau@linux.dev, netdev@vger.kernel.org, sdf@fomichev.me, song@kernel.org, syzkaller-bugs@googlegroups.com, linux-rt-devel@lists.linux.dev Subject: Re: [syzbot] [bpf?] WARNING in bpf_bprintf_prepare (3) Message-ID: <20251028075218.aw9YABrW@linutronix.de> References: <68f6a4c8.050a0220.1be48.0011.GAE@google.com> <14371cf8-e49a-4c68-b763-fa7563a9c764@linux.dev> <8dd359dd-b42f-4676-bb94-07288b38fac1@linux.dev> <95e1fd95-896f-4d33-956f-a0ef0e0f152c@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <95e1fd95-896f-4d33-956f-a0ef0e0f152c@linux.dev> On 2025-10-27 20:45:25 [-0700], Yonghong Song wrote: > This should work, but local lock disable interrupts which could have > negative side effects on the system. We don't want this. > That is the reason we have 3 nested level for bpf_bprintf_buffers. > > Please try my above preempt_disalbe/enable() solution. I meant to look into this yesterday but got distracted with other things. I try to take a look. Sebastian