From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 9E5C741161B for ; Mon, 9 Mar 2026 19:56:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773086173; cv=none; b=LMfRXVuiZNr9ZxlMfRDswuiNK0YtQKuFBsFs9vW+8bi+vTgsz0PLT6xwLGt0tqui7vMzPyy2qu8axj51DiDmhSQ3zAPgYltUjlrsIHJS7VmYrl9DJWxqqOw4iFEvWxSoI7esEWJhjvq2Z+mKa+WwZMUFnzZ5xM45lF6qTtF84QU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773086173; c=relaxed/simple; bh=A6AwkQvxJujn8gLfXjT5hCNqGSMzHSoUg98h4B1tY0k=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:content-type; b=HjHUcZHJ9BLEyZsBJge1h4NR3k9xiEbLDSQrYQF2aJQ7y7GbEFMil4hAiSKOHBA76U5bTlUBvqHRX6vxJ27RCRMOXI1ug6kU9kH+p+IWOw0oJVRDJzvaS3GOrpvImHFRn7VrE+qtBC0VQ4JvjJAmi+E4rjc68MI1MjcBAaD/8qA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=N8//i+v6; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="N8//i+v6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1773086170; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XE9tVL0amLnuy/qnOAxXmbfUZQ7BCSZ1Cf0kdtRjbNU=; b=N8//i+v6CDdFIueNIgpXyfc12TttlJA0HVuTawMKF8H7ntaCRQ6mKgbocGMbsxI04YLYdO dgEWA/gGH2lhkKADZKbujq2e7jGpkoWNp53i93x6VQ7qJtOidRS8XRbbarSw+cNrw9CDma EcKiSKkKowlwfAzh/Sow3p3Wt/s1v9A= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-564-LlUycme6NOGwpRd8itdufA-1; Mon, 09 Mar 2026 15:56:07 -0400 X-MC-Unique: LlUycme6NOGwpRd8itdufA-1 X-Mimecast-MFC-AGG-ID: LlUycme6NOGwpRd8itdufA_1773086165 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9E34D1800359; Mon, 9 Mar 2026 19:56:04 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.22.81.10]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D1F3330002D2; Mon, 9 Mar 2026 19:55:59 +0000 (UTC) From: Wander Lairson Costa To: Steven Rostedt , Tomas Glozar , Wander Lairson Costa , Ivan Pravdin , Crystal Wood , Costa Shulyupin , John Kacur , Tiezhu Yang , Daniel Bristot de Oliveira , Daniel Wagner , linux-trace-kernel@vger.kernel.org (open list:Real-time Linux Analysis (RTLA) tools), linux-kernel@vger.kernel.org (open list:Real-time Linux Analysis (RTLA) tools), bpf@vger.kernel.org (open list:BPF [MISC]:Keyword:(?:\b|_)bpf(?:\b|_)) Subject: [PATCH v4 03/18] rtla/actions: Simplify argument parsing Date: Mon, 9 Mar 2026 16:46:16 -0300 Message-ID: <20260309195040.1019085-4-wander@redhat.com> In-Reply-To: <20260309195040.1019085-1-wander@redhat.com> References: <20260309195040.1019085-1-wander@redhat.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Mimecast-MFC-PROC-ID: YLUwgZMCSG4KvKJILjxNkMme6IXJQXcfxGnbGqIVRW0_1773086165 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true The actions_parse() function uses open-coded logic to extract arguments from a string. This includes manual length checks and strncmp() calls, which can be verbose and error-prone. To simplify and improve the robustness of argument parsing, introduce a new extract_arg() helper macro. This macro extracts the value from a "key=value" pair, making the code more concise and readable. Also, introduce STRING_LENGTH() and strncmp_static() macros to perform compile-time calculations of string lengths and safer string comparisons. Refactor actions_parse() to use these new helpers, resulting in cleaner and more maintainable code. Signed-off-by: Wander Lairson Costa --- tools/tracing/rtla/src/actions.c | 57 +++++++++++++++++++++++--------- tools/tracing/rtla/src/utils.h | 10 ++++++ 2 files changed, 52 insertions(+), 15 deletions(-) diff --git a/tools/tracing/rtla/src/actions.c b/tools/tracing/rtla/src/actions.c index 0ac42ffd734a3..b0d68b5de08db 100644 --- a/tools/tracing/rtla/src/actions.c +++ b/tools/tracing/rtla/src/actions.c @@ -111,6 +111,29 @@ actions_add_continue(struct actions *self) action->type = ACTION_CONTINUE; } +static inline const char *__extract_arg(const char *token, const char *opt, size_t opt_len) +{ + const size_t tok_len = strlen(token); + + if (tok_len <= opt_len) + return NULL; + + if (strncmp(token, opt, opt_len)) + return NULL; + + return token + opt_len; +} + +/* + * extract_arg - extract argument value from option token + * @token: option token (e.g., "file=trace.txt") + * @opt: option name to match (e.g., "file") + * + * Returns pointer to argument value after "=" if token matches "opt=", + * otherwise returns NULL. + */ +#define extract_arg(token, opt) __extract_arg(token, opt "=", STRING_LENGTH(opt "=")) + /* * actions_parse - add an action based on text specification */ @@ -120,6 +143,7 @@ actions_parse(struct actions *self, const char *trigger, const char *tracefn) enum action_type type = ACTION_NONE; const char *token; char trigger_c[strlen(trigger) + 1]; + const char *arg_value; /* For ACTION_SIGNAL */ int signal = 0, pid = 0; @@ -152,12 +176,10 @@ actions_parse(struct actions *self, const char *trigger, const char *tracefn) if (token == NULL) trace_output = tracefn; else { - if (strlen(token) > 5 && strncmp(token, "file=", 5) == 0) { - trace_output = token + 5; - } else { + trace_output = extract_arg(token, "file"); + if (!trace_output) /* Invalid argument */ return -1; - } token = strtok(NULL, ","); if (token != NULL) @@ -169,17 +191,21 @@ actions_parse(struct actions *self, const char *trigger, const char *tracefn) case ACTION_SIGNAL: /* Takes two arguments, num (signal) and pid */ while (token != NULL) { - if (strlen(token) > 4 && strncmp(token, "num=", 4) == 0) { - if (strtoi(token + 4, &signal)) - return -1; - } else if (strlen(token) > 4 && strncmp(token, "pid=", 4) == 0) { - if (strncmp(token + 4, "parent", 7) == 0) - pid = -1; - else if (strtoi(token + 4, &pid)) + arg_value = extract_arg(token, "num"); + if (arg_value) { + if (strtoi(arg_value, &signal)) return -1; } else { - /* Invalid argument */ - return -1; + arg_value = extract_arg(token, "pid"); + if (arg_value) { + if (strncmp_static(arg_value, "parent") == 0) + pid = -1; + else if (strtoi(arg_value, &pid)) + return -1; + } else { + /* Invalid argument */ + return -1; + } } token = strtok(NULL, ","); @@ -194,9 +220,10 @@ actions_parse(struct actions *self, const char *trigger, const char *tracefn) case ACTION_SHELL: if (token == NULL) return -1; - if (strlen(token) > 8 && strncmp(token, "command=", 8)) + arg_value = extract_arg(token, "command"); + if (!arg_value) return -1; - actions_add_shell(self, token + 8); + actions_add_shell(self, arg_value); break; case ACTION_CONTINUE: /* Takes no argument */ diff --git a/tools/tracing/rtla/src/utils.h b/tools/tracing/rtla/src/utils.h index e29c2eb5d569d..11458676f607d 100644 --- a/tools/tracing/rtla/src/utils.h +++ b/tools/tracing/rtla/src/utils.h @@ -14,6 +14,16 @@ #define MAX_NICE 20 #define MIN_NICE -19 +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) +#endif + +/* Calculate string length at compile time (excluding null terminator) */ +#define STRING_LENGTH(s) (ARRAY_SIZE(s) - sizeof(*(s))) + +/* Compare string with static string, length determined at compile time */ +#define strncmp_static(s1, s2) strncmp(s1, s2, ARRAY_SIZE(s2)) + #define container_of(ptr, type, member)({ \ const typeof(((type *)0)->member) *__mptr = (ptr); \ (type *)((char *)__mptr - offsetof(type, member)) ; }) -- 2.53.0