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 E4E1F946C for ; Sat, 20 Jul 2024 15:52:55 +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=1721490776; cv=none; b=KXQ6vbZj+X4A9nGJmIKqdnAePSTsNAlt3IO7aF+DExQF/q51NhtTHhLIa96FEtIbslgFgmNVrZTRs8SZDj03IIDhKn0Woex9iRGZI7AAXKYEC585oqhi83gdCZHbOZzxAhcGBQ4tV1U9o04dF7OOH56zDoFK7wJhsyyrRjt1qjg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721490776; c=relaxed/simple; bh=srZx9P49tkcXXP6EyGkWVlnmXXFOW2xRRQGVvtpPnxA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=kVA6B+SRSziAQoInC3EKCOKO76NABx5igpot0lOSv6/r17QtVioHqKX8FFwdZcG0xxZUava4PrZhKp8AHl0wDzy8ByFn5WIfEF/j33Hf1jGODP9/FMmnTy6EmK+gKaNMjEZp9R5kKcmYZnQkIJ3Y2YxQy+SS5EQDIooGOd1yG/k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ld+TArm9; 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="ld+TArm9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A134C2BD10; Sat, 20 Jul 2024 15:52:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721490775; bh=srZx9P49tkcXXP6EyGkWVlnmXXFOW2xRRQGVvtpPnxA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ld+TArm9ku21GBxx6Mr/DPgk/z0yMRfYE+q4qulYHUQE9FOswjmaMzC2m0mw3/vto XiVLTDbUahmys0bO8L3YCJeKPyfeqk5wePEGEG7BaeTr44qPrfmU/RHG6L7+JP2005 MuX+z8TVadCAmanyzV4OKNq3b3ElEOCt1C44qcGE7CHXaYnN2c2GWwls6uAW+ybtOY G9Im6ol8ur2gwCOCLdwC0tVKqPmjBFIkdGYAeDjvC90eA7dJbZvGrzB4l3DLzZ6uHf 6mdBpxRuRDVZknzdkGYMgMKihmk4+qOrYDDepQ/2dXY4dTsi8GrqGma+HmsOSZfo4+ CRQuE42xGUcjA== Date: Sun, 21 Jul 2024 00:52:52 +0900 From: Masami Hiramatsu (Google) To: Dan Carpenter Cc: linux-trace-kernel@vger.kernel.org Subject: Re: [bug report] tracing/kprobes: Add symbol counting check when module loads Message-Id: <20240721005252.3a5face397b8c4f8096d363b@kernel.org> In-Reply-To: <1c775c89-42fe-4c86-ac6d-d97170885ae8@stanley.mountain> References: <1c775c89-42fe-4c86-ac6d-d97170885ae8@stanley.mountain> 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=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 18 Jul 2024 13:30:57 -0500 Dan Carpenter wrote: > Hello Masami Hiramatsu (Google), > > Commit 9d8616034f16 ("tracing/kprobes: Add symbol counting check when > module loads") from Jul 5, 2024 (linux-next), leads to the following > Smatch static checker warning: > > kernel/trace/trace_kprobe.c:828 validate_probe_symbol() > warn: missing error code here? 'try_module_get_by_name()' failed. 'ret' = '0' > > kernel/trace/trace_kprobe.c > 815 static int validate_probe_symbol(char *symbol) > 816 { > 817 struct module *mod = NULL; > 818 char *modname = NULL, *p; > 819 int ret = 0; > 820 > 821 p = strchr(symbol, ':'); > 822 if (p) { > 823 modname = symbol; > 824 symbol = p + 1; > 825 *p = '\0'; > 826 mod = try_module_get_by_name(modname); > 827 if (!mod) > --> 828 goto out; > > Is it intentional that "ret = 0;" here? Yes, hm, I dropped an important message here. If you see the commit 9d8616034f16, you can see there was; /* Return 0 (defer) if the module does not exist yet. */ So it is intentional. But thanks for reporting. It should be cleaned up. Thank you, > > 829 } > 830 > 831 ret = validate_module_probe_symbol(modname, symbol); > 832 out: > 833 if (p) > 834 *p = ':'; > 835 if (mod) > 836 module_put(mod); > 837 return ret; > 838 } > > regards, > dan carpenter -- Masami Hiramatsu (Google)