From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2D20D156C5F; Fri, 6 Sep 2024 22:57:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725663465; cv=none; b=CXVDc0sAxTVY8ChGhm6mOLRUN7CtAVCL43wVvaRcqqfLABu7sYvAzf7Lv48+msJync2ALJedr1bOskB9KokBiA9g2sry01rDy911vBA8tsa8uxYAJaT0a65TRu6GpllefRy+kYcVfM4KHKznMVeHAqe6obLh8y/YWSECnr2HR24= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725663465; c=relaxed/simple; bh=x2gJ5IUDvpyP1YM2UKkmoW200N0zbYR1iUQWJXBHFFE=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=DF9lMx9jQakaLKRTgF/gzExP/GzjvZXL+j0GObgkuMbowKl+kBV/QADlL1ApiWXENwG4fDKpTwcsmUicXZTsSHxFGf+oXYZLfJq3nTvBzWX+t/bPP37qQGK+iAJ+3tqdhpJK9vthuLi9YnSvPqTtOxhIm/XcOHMtyTcJkGTCmXc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eze8qPjw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eze8qPjw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7272DC4CEC8; Fri, 6 Sep 2024 22:57:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725663464; bh=x2gJ5IUDvpyP1YM2UKkmoW200N0zbYR1iUQWJXBHFFE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=eze8qPjw/jll/6hOiZtjE0KB9HjMFIBRV9ifAt3p6cInnwVgyMNm2tXduB7vNU8AC 2Hlw5shArlaAovGFpcw6DnR46hJYaBADYjtNi0Fpjojfyfn6T5wwaFfyMh9rOPiav3 RNvxOQaz+Und3D7lircT19lAzyL6KEURCWHdIJnYxA6YVy0Hyxf66xCbyzjMPfGU0l Na279/WM3zX6CJnn8bBcO49As7taD7qff0HD8D2e20MQ3GJ3YcE3lyYBRABscCJVWX 3jC7UZt+74HltHrQHMpD5MK739WXM5gfTalCg0HUok1A9muBSY+H6gEI7/HL+CuVF1 2ILt68Ylk5QWg== Date: Fri, 6 Sep 2024 15:57:42 -0700 From: Jakub Kicinski To: Alexei Starovoitov Cc: Philo Lu , bpf , Eric Dumazet , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Martin KaFai Lau , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eddy Z , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , "David S. Miller" , Paolo Abeni , Mykola Lysenko , Shuah Khan , Maxime Coquelin , Alexandre Torgue , Kui-Feng Lee , Juntong Deng , jrife@google.com, Alan Maguire , Dave Marchevsky , Daniel Xu , Viktor Malik , Cupertino Miranda , Matt Bobrowski , Xuan Zhuo , Network Development , linux-trace-kernel Subject: Re: [PATCH bpf-next v2 3/5] tcp: Use skb__nullable in trace_tcp_send_reset Message-ID: <20240906155742.0bd4d4e3@kernel.org> In-Reply-To: References: <20240905075622.66819-1-lulie@linux.alibaba.com> <20240905075622.66819-4-lulie@linux.alibaba.com> <20240906152300.634e950b@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 6 Sep 2024 15:41:47 -0700 Alexei Starovoitov wrote: > The urgency is now because the situation is dire. > The verifier assumes that skb is not null and will remove > if (!skb) check assuming that it's a dead code. Meaning verifier currently isn't ready for patch 4? Or we can crash 6.11-rc6 by attaching to a trace_tcp_send_reset() and doing printf("%d\n", skb->len); ?