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 17E722628C; Wed, 16 Jul 2025 04:16:57 +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=1752639418; cv=none; b=IzzHELrtRKTOgU2rqGrPfx6upTPZKbW0USyRoHey3V7yKp0sCMUt2Oc1N43AdpZhScJEqgsO0m3h/5CxB5r3RLpmooRTD3Eoi2UKo+lv0lFXZrViDO2jN63sIsF1X/s2YFF5JYI/sfJ9XpkM6UuJApOVtY6wScqxSKLnb1DivoI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752639418; c=relaxed/simple; bh=5mUglmWt+DtfiWzS7JbWNY3rOgVqbEQ28VtYDouYkBs=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=Ka6EnczAz+sBOpHzAWJpdhhZTI4n2BMNxne0qlCXptdNN80ZKwZ9InxxNNJNel+FXz7zjbFe6neZmiMSJyeaQ667xhfcaU9fWlnMsgS61KQSG0xdfi05eBhm0GHxM2oIkO3jGkViNQyU4RXgXNEImnmdLqbREMi615SkN0bYC9U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RFTS/5dv; 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="RFTS/5dv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64D09C4CEF0; Wed, 16 Jul 2025 04:16:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752639417; bh=5mUglmWt+DtfiWzS7JbWNY3rOgVqbEQ28VtYDouYkBs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RFTS/5dvr7V2c3NMRqT+e+4xcsNVwPIiT1ektGIZa5EaHUtpA0Wimmp1AEuTnpHLz usJgTTUcM/R7HLgC6g++WuFmWeOqW9BL+OYAtTdJMpEbrbB+vlyf1pacQaWLnwkzRV oR3dIxTtu4dh7S6x9XgYS0uBuI4Ww3V0DrfBSkXJlE0gzOB9HiEJED4YLFyBSf6LN/ LQzqzgzlWnH+LId1juHSIM58l126KiLtw1uKOIXmZ+n4fQ4rKvdXtHrSAiVyGaRRvm qvp4mFoPZFhEVl51BWry8WOlAKB8AmfzFJ7QvkX2E9jQnuU248RIyTmfujmyAThFhV rzfqGsl8SoYPA== Date: Wed, 16 Jul 2025 13:16:54 +0900 From: Masami Hiramatsu (Google) To: Nathan Chancellor Cc: Steven Rostedt , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, llvm@lists.linux.dev, stable@vger.kernel.org Subject: Re: [PATCH] tracing/probes: Avoid using params uninitialized in parse_btf_arg() Message-Id: <20250716131654.93b969d6eab59b0cd292a3f3@kernel.org> In-Reply-To: <20250715-trace_probe-fix-const-uninit-warning-v1-1-98960f91dd04@kernel.org> References: <20250715-trace_probe-fix-const-uninit-warning-v1-1-98960f91dd04@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 15 Jul 2025 20:19:44 -0700 Nathan Chancellor wrote: > After a recent change in clang to strengthen uninitialized warnings [1], > it points out that in one of the error paths in parse_btf_arg(), params > is used uninitialized: > > kernel/trace/trace_probe.c:660:19: warning: variable 'params' is uninitialized when used here [-Wuninitialized] > 660 | return PTR_ERR(params); > | ^~~~~~ > > Match many other NO_BTF_ENTRY error cases and return -ENOENT, clearing > up the warning. Good catch! let me pick this up. Thank you, > > Cc: stable@vger.kernel.org > Closes: https://github.com/ClangBuiltLinux/linux/issues/2110 > Fixes: d157d7694460 ("tracing/probes: Support BTF field access from $retval") > Link: https://github.com/llvm/llvm-project/commit/2464313eef01c5b1edf0eccf57a32cdee01472c7 [1] > Signed-off-by: Nathan Chancellor > --- > kernel/trace/trace_probe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > index 424751cdf31f..40830a3ecd96 100644 > --- a/kernel/trace/trace_probe.c > +++ b/kernel/trace/trace_probe.c > @@ -657,7 +657,7 @@ static int parse_btf_arg(char *varname, > ret = query_btf_context(ctx); > if (ret < 0 || ctx->nr_params == 0) { > trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); > - return PTR_ERR(params); > + return -ENOENT; > } > } > params = ctx->params; > > --- > base-commit: 6921d1e07cb5eddec830801087b419194fde0803 > change-id: 20250715-trace_probe-fix-const-uninit-warning-7dc3accce903 > > Best regards, > -- > Nathan Chancellor > -- Masami Hiramatsu (Google)