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 A3D0B8BE7; Sun, 26 May 2024 23:13:09 +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=1716765190; cv=none; b=GkYa1zOKzNceTHbbkqjVvfFQYnp02A2iLZZLa1nhrmdgEdN++6GOxloOJ5dlZwi9IpaY/Pz2C3wXTxsmVX4C+xNqNwwBaEjLH5iPnYXGkvu72KgsS2f5rQHvS+fWzldG+hXmzG9n6SuyoDH3+mBoRqjKsHdp3KuvQrBgaMy5HII= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716765190; c=relaxed/simple; bh=5XNbmK1GMH0k0hqdPzWAk8W4SET/yQZHDoHkWs60AHA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=Ih3HwLA0Dh0hqTh1wPAP1+eNMN3kA+FCuihxHxm0uEAfujinScePuZwCYTT7MQKKH9OVXSBgJlmoKVwBcVlBnAGc1Dkh/koZZllFZk5F20o/gks6Ed66daDI1Xtx5Wj8m3m/roiSia2i7foenS+8yGU74oc2AkIrA8IXN9Xx8jM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IaC4aVav; 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="IaC4aVav" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 511A8C2BD10; Sun, 26 May 2024 23:13:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716765189; bh=5XNbmK1GMH0k0hqdPzWAk8W4SET/yQZHDoHkWs60AHA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IaC4aVavecDuaPc3f+KW+vB5Zf9a6oNsGMubqfHm292P13hsLogIHU7AVDnJZBgVG yI7wda9yb9c0mji1UZZEtHqibjiekAFCG1bR1LBZlKWTs/Sov+Hy3smPWky8wVDg5X kE2cigOTyYd5tqpmUhVNzGFpSaIgvAfAxkr/9SKYVn+f8ncXIEULTSVaxnmnWsOl95 B6sFMDyDQgMPZ8nTjLVUyLNiEWde6aSKR0O11LfV0hbXoDBt8YVWC0oizzURr4Xd5p h3SmNxJCKT/KmvGkK/sKBnT6fVMedTR3NIjEYYhYkUdCXBnp+LJ/9xzWmCUkwPLtBJ J6aEl4bC3vyPw== Date: Mon, 27 May 2024 08:13:04 +0900 From: Masami Hiramatsu (Google) To: Carlos =?UTF-8?B?TMOzcGV6?= Cc: linux-trace-kernel@vger.kernel.org, Steven Rostedt , Mathieu Desnoyers , Alan Maguire , "open list:TRACING" Subject: Re: [PATCH] tracing/probes: fix error check in parse_btf_field() Message-Id: <20240527081304.8b91f75548838a0781288688@kernel.org> In-Reply-To: References: <20240525182131.15740-1-clopez@suse.de> <20240526191708.860651c915600a535cc2e579@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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=UTF-8 Content-Transfer-Encoding: 8bit On Sun, 26 May 2024 14:27:56 +0200 Carlos López wrote: > > Hi, > > On 26/5/24 12:17, Masami Hiramatsu (Google) wrote: > > On Sat, 25 May 2024 20:21:32 +0200 > > Carlos López wrote: > > > >> btf_find_struct_member() might return NULL or an error via the > >> ERR_PTR() macro. However, its caller in parse_btf_field() only checks > >> for the NULL condition. Fix this by using IS_ERR() and returning the > >> error up the stack. > >> > > > > Thanks for finding it! > > I think this requires new error message for error_log file. > > Can you add the log as > > > > trace_probe_log_err(ctx->offset, BTF_ERROR); > > > > And define BTF_ERROR in ERRORS@kernel/trace/trace_probe.h ? > > Sounds good, but should we perhaps reuse BAD_BTF_TID? > > ``` > C(BAD_BTF_TID, "Failed to get BTF type info."),\ > ``` > > `btf_find_struct_member()` fails if `type` is not a struct or if it runs > OOM while allocating the anon stack, so it seems appropriate. Good point, it sounds reasonable. Thanks! > > Best, > Carlos > > > Thank you, > > > >> Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access") > >> Signed-off-by: Carlos López > >> --- > >> kernel/trace/trace_probe.c | 2 ++ > >> 1 file changed, 2 insertions(+) > >> > >> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > >> index 5e263c141574..5417e9712157 100644 > >> --- a/kernel/trace/trace_probe.c > >> +++ b/kernel/trace/trace_probe.c > >> @@ -554,6 +554,8 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type, > >> anon_offs = 0; > >> field = btf_find_struct_member(ctx->btf, type, fieldname, > >> &anon_offs); > >> + if (IS_ERR(field)) > >> + return PTR_ERR(field); > >> if (!field) { > >> trace_probe_log_err(ctx->offset, NO_BTF_FIELD); > >> return -ENOENT; > >> -- > >> 2.35.3 > >> > > > > > > -- > Carlos López > Security Engineer > SUSE Software Solutions -- Masami Hiramatsu (Google)