From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-174.mta1.migadu.com (out-174.mta1.migadu.com [95.215.58.174]) (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 90330348C7D for ; Thu, 16 Jul 2026 08:01:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784188886; cv=none; b=NyaSflFP6DfKCL6rUfsa+tk1IqpiY5OQxsrDUrMiv3A3RQqEUjFKRagxT6K6bLVi4XmVh8Q10qeUzMovTj1qjPMBLEQDtvzfbz3I1ZXsReC0E+ZuceaQPQfLsRH/1+70fLgcn/k081CpGIJ+OykAAcJjsvdYTBtbz1KqKE2HvBU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784188886; c=relaxed/simple; bh=/2Hys85UdvGh+siSTWXF/43ktg9C4EZ8mkEVwsTG90Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=SpS0Fazg4HxF82WNwJB4OfjmdG0xTIq2dxtoN7bagSiYn9ECx1YCGKfDsjgQ2PZ/9IDOD7TU59pX+466JCMZ+WrpZXICWxGcgC9dZWS2MwaubQaJIHdbEImyuSymLeVgYaAT+t4Wk/CHjYPkpOpfk3kXorZT5JsUgFtpje0tcZg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=JqYsjz2Q; arc=none smtp.client-ip=95.215.58.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="JqYsjz2Q" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1784188882; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N6/joMqxfQrU9eDe2vBG1p3OB2Jd1Iz66PvDymTd85c=; b=JqYsjz2QuYTFEBK4QUsFZcIwLrNfalShn91XGEZVz+ryu5FCtNAqp1d53IpuSwzZ8IYG0+ GGi/wb2QhQCOQmkjUNWFmTEF21/3Hf63QVO5lBgiHw6L2soPp8CwwZWcS97DNQ7dJgaGXv 5YGeTUEZfBtagBI3iYGNb9jEskqMWf4= Date: Thu, 16 Jul 2026 16:01:05 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next] bpf:syscall: Log error code on trampoline unlink failure To: xu.xin16@zte.com.cn Cc: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, eddyz87@gmail.com, memxor@gmail.com, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, emil@etsalapatis.com, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, xu.xin@linux.dev References: <20260716150330696WUY2gk5CaNNaxqm2ggKWL@zte.com.cn> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Leon Hwang Content-Language: en-US In-Reply-To: <20260716150330696WUY2gk5CaNNaxqm2ggKWL@zte.com.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 16/7/26 15:03, xu.xin16@zte.com.cn wrote: >>>>> Well, the crash may happen when the kernel is booting, or too hard to reproduce, >>>>> in which case, bpftrace does not work. >>>> >>>> >>>> Do you enable kernel.panic_on_warn sysctl? >>>> >>>> If it's not enabled, the kernel won't crash, I think. >>> >>> I'd like to clarify that the panic in our case is not triggered by the WARN itself. >>> Instead, the real crash is a use‑after‑free (UAF) that happens when one CPU is >>> executing a trampoline while another CPU is concurrently freeing it. This results >>> in an illegal instruction (or page fault) at the PC, which is fatal and will panic >>> the kernel regardless of panic_on_warn – because it's an Oops with Fatal exception >>> in interrupt. >> >> >> Why not fix the root cause instead? >> >> If you want some help from upstream to fix the root cause, pls provide >> the crash dmesg and the reproducing demo. > > It's already fixed due to some OOT drivers. > > I think if we have this patch, it can speed up trouble-shooting. OK. Let's wait for Jiri's opinion. Thanks, Leon