From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 F06B56AD7 for ; Fri, 15 Sep 2023 09:37:08 +0000 (UTC) Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA41819BC for ; Fri, 15 Sep 2023 02:37:06 -0700 (PDT) Received: by mail-ej1-x62b.google.com with SMTP id a640c23a62f3a-9aa2c6f0806so249456366b.3 for ; Fri, 15 Sep 2023 02:37:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1694770625; x=1695375425; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=k07mrQgvr71mnGbvfxEmEgVEHuj2PPd+FW0mOyTAgdc=; b=Zxd6vvMwtd/w2KAVOlIvP4evJAJW208wtxdyQyR0UNqSEua59ZuBi+C/uezpH0kqoQ nyzNSw+U00izJOfqYH2onH539+UgiEh++uwOuIcHOKvHYvnyc70XEyR1xtLvwxv7TZIa Z1xie8S0/JvxPYPlAo2Z+sgK34HADkVJ4sBp5X8kb95OmGC8o1GvF1LSrg4kYt4f9jax QQ3CFSoMxDDPi5te1AuAp9auqyWp6E6seOD8qtl4RMQjRdP0F7mNu+pBVog32RJk+9gl YVgYzTbJSk5zs753HR9uA6JBGR0gRXC8JPCBliI5iDMqDKqEGYtjGwacEEw0GbZilF3w pHog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694770625; x=1695375425; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=k07mrQgvr71mnGbvfxEmEgVEHuj2PPd+FW0mOyTAgdc=; b=VOJsVWsKhqcOewPrGMJTaYTkTmo3p45FUiQEzpRWooCKMGrOGChIy7Ch1hl4CTlWHr ZTSs5ULB7nZmAgGU3rpeJix19ifHVUHvX3HbcyULuCkPGeVK4Kb35i7aWLnOk1p9c1zK 7QuxW1dmmls+OYEc0igTCjNSSPXrqgcb2815yhWx1fN3liBDDNPZ+XZDPmeJ/SE4LsJs e6UiW3C5aGjdH9DeAP6J8hm0TtxcR1vkKkKs8Fj8rTOVT9w10AlUq9vqMut6/97wnnXT fKlHcmH4YfV5++amjY6iSIABPjeOktgijD/8JsNq2lJ+k4vGjOhknNIU+PGR0qxKDqIQ t7nw== X-Gm-Message-State: AOJu0Ywyrx1arSWMDjHR8SObcXQ8+FysJNiAXuRR0y5xfc/Ft2GjbHzm ZH/nHLfKc2NH+idK8QtIYNw= X-Google-Smtp-Source: AGHT+IHZAva+2KzVmZ8PzQNbKKPbC63wVPJjklwutTdJGyBdg4OCL8XhBZx9XS7JwI9YPG1RXcqWWQ== X-Received: by 2002:a17:906:5a5a:b0:99c:55c0:ad15 with SMTP id my26-20020a1709065a5a00b0099c55c0ad15mr914526ejc.38.1694770625049; Fri, 15 Sep 2023 02:37:05 -0700 (PDT) Received: from krava ([83.240.60.47]) by smtp.gmail.com with ESMTPSA id p8-20020a1709061b4800b0099c53c44083sm2156306ejg.79.2023.09.15.02.37.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Sep 2023 02:37:04 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Fri, 15 Sep 2023 11:37:02 +0200 To: Dan Carpenter Cc: bpf@vger.kernel.org Subject: Re: [bug report] bpf: Add pid filter support for uprobe_multi link Message-ID: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Fri, Sep 15, 2023 at 10:12:34AM +0300, Dan Carpenter wrote: > Hello Jiri Olsa, > > The patch b733eeade420: "bpf: Add pid filter support for uprobe_multi > link" from Aug 9, 2023 (linux-next), leads to the following Smatch > static checker warning: > > kernel/trace/bpf_trace.c:3227 bpf_uprobe_multi_link_attach() > warn: missing error code here? 'get_pid_task()' failed. 'err' = '0' > > kernel/trace/bpf_trace.c > 3217 err = -EBADF; > 3218 goto error_path_put; > 3219 } > 3220 > 3221 pid = attr->link_create.uprobe_multi.pid; > 3222 if (pid) { > 3223 rcu_read_lock(); > 3224 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); > 3225 rcu_read_unlock(); > 3226 if (!task) > --> 3227 goto error_path_put; > > Should this have an error code? yes, it should.. I'll send the fix below thanks, jirka --- diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index c1c1af63ced2..868008f56fec 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3223,8 +3223,10 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr rcu_read_lock(); task = get_pid_task(find_vpid(pid), PIDTYPE_PID); rcu_read_unlock(); - if (!task) + if (!task) { + err = -ESRCH; goto error_path_put; + } } err = -ENOMEM;