From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 BFCA6382F23; Tue, 8 Sep 2026 06:22:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788848544; cv=none; b=T2hKuzneAhcDwdlPfDvdtldOfrqkevUy70K5KAsVNhPeQuJCarmICYyUHwC9CIetOMUKhwvxZIitrhzcX1LkOutmrH+yHRkrY/CyP06JK/saIeSx+kFAMUuR98oc59tz49sYndXseqwSNyDsSiVKEU4a6N3OwmJA27Z0Qq2ffKA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788848544; c=relaxed/simple; bh=frgMevK5TVhiaL5RJpv209UOvEFNyDdYVbihdVW1tJ8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=pyko8ew2DUOK7wDmBJ7GWT1nsnubMDTo2IcVJNdd0WwDwpFIht14SHcxHvIiA1AhZh517w26AzfYBASqC7FA7cfjamdOEYNhOhYmybLnMBEWVNhVXfhta8Hmp+IybG6eMJTh+mBiAMCSzEaQaA1nkgPZfOhw7s0VCel4WDXN+jQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=rs5rvv9b; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=iEIntkcz; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="rs5rvv9b"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="iEIntkcz" From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1788848540; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FbKyjWw5mfZHH0FX6Zh5pd3WFdFK8W+TfufQoK8ZQGQ=; b=rs5rvv9b8g4M4Cfyl39TyfZ+IMCKWKkLj5j/HDCUHviGL7lAIp8OxSezqolC7B0SqRffdP 1pRiYTRnqX8iVv4BumM0UJ1eHyxSbOk2IeHvARCgcLGTz7VKsMQ5rBPS2l6fGP1+VnPvNr E5tCpNh58uUmrkBh3ci0IbL60EEw0qr/JVOlNLU0zO0EMCm/p2lTVTOi9ih21EY59eVQ/W 2Qlanv0CgGe0g07eoFd9ea4AEQ9NS+jEpKm9LLiiffbPZNEu97gCsiwKMMM4fXJJUSmHt4 2+4BKmaTSmIAfMxI5kZdgLnsyUgvPfgPiUomh1OtitLEiqimmcw0I7rBfWsU1Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1788848540; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FbKyjWw5mfZHH0FX6Zh5pd3WFdFK8W+TfufQoK8ZQGQ=; b=iEIntkcz+LIDM0UmBJ829O1ZYbgdhIU6QNxGmOgH25r/+g54GewTuDl+7Pscgms5EmMjCT CTamRlOFNI+HttDQ== Date: Tue, 08 Sep 2026 08:22:21 +0200 Subject: [PATCH v2 7/7] tracing: Parse filter from boot event string 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 Message-Id: <20260908-tracing-cli-event-filter-v2-7-05396a3fb663@linutronix.de> References: <20260908-tracing-cli-event-filter-v2-0-05396a3fb663@linutronix.de> In-Reply-To: <20260908-tracing-cli-event-filter-v2-0-05396a3fb663@linutronix.de> To: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Developer-Signature: v=1; a=ed25519-sha256; t=1788848535; l=8735; i=thomas.weissschuh@linutronix.de; s=20240209; h=from:subject:message-id; bh=frgMevK5TVhiaL5RJpv209UOvEFNyDdYVbihdVW1tJ8=; b=qYDgbBKKc7G/UYGZrxg7iQhbfFk4xfG+6cwPAR+qYc1Wbrc39ACv/w5FcDdccSeVIqTM5dWXY wV6Ay+5QKPxB6xwWqRsShtu2MAlv3e+Hd83sN4wAbSb1fryhQxvh0MU X-Developer-Key: i=thomas.weissschuh@linutronix.de; a=ed25519; pk=pfvxvpFUDJV2h2nY0FidLUml22uGLSjByFbM6aqQQws= Make it possible to specify a trace event filter from the kernel command line. Example: trace_event=syscalls:sys_enter_clock_nanosleep:filter:which_clock==0 Signed-off-by: Thomas Weißschuh --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++++-- Documentation/trace/events.rst | 5 +++++ include/linux/trace_events.h | 2 +- kernel/trace/trace.h | 3 ++- kernel/trace/trace_boot.c | 2 +- kernel/trace/trace_events.c | 27 +++++++++++++++++-------- kernel/trace/trace_events_test.c | 26 +++++++++++++++++++++--- 7 files changed, 58 insertions(+), 16 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 68647ff4bdd2..63347a986706 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -7769,8 +7769,13 @@ Kernel parameters trace_event=:mod: The value before :mod: will only enable specific events - that are part of the module. See the above mentioned - document for more information. + that are part of the module. + + To apply a filter, use the :filter: keyword: + + trace_event=...:filter: + + See the above mentioned document for more information. trace_instance=[instance-info] [FTRACE] Create a ring buffer instance early in boot up. diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst index 581f2260614b..6ce53372acbc 100644 --- a/Documentation/trace/events.rst +++ b/Documentation/trace/events.rst @@ -118,6 +118,11 @@ In order to facilitate early boot debugging, use boot option:: event-list is a comma separated list of events. See section 2.1 for event format. +The boot option also supports the ``:filter:`` keyword to apply a filter. +The ``:filter:`` keyword needs to be at the end of the event specification:: + + ::mod::filter: + 3. Defining an event-enabled tracepoint ======================================= diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index af46614bc75d..c1f6bb94f483 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -882,7 +882,7 @@ extern int trace_add_event_call(struct trace_event_call *call); extern int trace_remove_event_call(struct trace_event_call *call); extern int trace_event_get_offsets(struct trace_event_call *call); -int ftrace_set_clr_event(struct trace_array *tr, const char *buf, int set); +int ftrace_set_clr_event(struct trace_array *tr, const char *buf, int set, bool handle_filter); int trace_set_clr_event(const char *system, const char *event, int set); int trace_array_set_clr_event(struct trace_array *tr, const char *system, const char *event, bool enable); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 35f619a1655e..2ec212d90192 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -2508,5 +2508,6 @@ static inline int rv_init_interface(void) #endif /* _LINUX_KERNEL_TRACE_H */ #if IS_ENABLED(CONFIG_KUNIT) -void ftrace_parse_event_string(char *buf, char **match, char **sub, char **event, char **mod); +void ftrace_parse_event_string(char *buf, char **match, char **sub, char **event, char **mod, + bool handle_filter, char **filter); #endif diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 5da0a8bbb110..6ba70dac1f06 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -94,7 +94,7 @@ trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node) continue; } - if (ftrace_set_clr_event(tr, buf, 1) < 0) + if (ftrace_set_clr_event(tr, buf, 1, false) < 0) pr_err("Failed to enable event: %s\n", p); } } diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index f8881a9d3c7a..2e2815d95c56 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1455,10 +1455,21 @@ static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, } VISIBLE_IF_KUNIT void -ftrace_parse_event_string(char *buf, char **match, char **sub, char **event, char **mod) +ftrace_parse_event_string(char *buf, char **match, char **sub, char **event, char **mod, + bool handle_filter, char **filter) { *event = NULL; *sub = NULL; + *filter = NULL; + + /* event filters can be appended with :filter: */ + if (handle_filter) { + *filter = strstr(buf, ":filter:"); + if (*filter) { + **filter = '\0'; + *filter += 8; + } + } /* Modules events can be appended with :mod: */ *mod = strstr(buf, ":mod:"); @@ -1498,9 +1509,9 @@ ftrace_parse_event_string(char *buf, char **match, char **sub, char **event, cha } EXPORT_SYMBOL_IF_KUNIT(ftrace_parse_event_string); -int ftrace_set_clr_event(struct trace_array *tr, const char *arg_buf, int set) +int ftrace_set_clr_event(struct trace_array *tr, const char *arg_buf, int set, bool handle_filter) { - char *event, *sub, *match, *mod; + char *event, *sub, *match, *mod, *filter; if (!tr) return -ENOENT; @@ -1509,9 +1520,9 @@ int ftrace_set_clr_event(struct trace_array *tr, const char *arg_buf, int set) if (!dupped_buf) return -ENOMEM; - ftrace_parse_event_string(dupped_buf, &match, &sub, &event, &mod); + ftrace_parse_event_string(dupped_buf, &match, &sub, &event, &mod, handle_filter, &filter); - return __ftrace_set_clr_event(tr, match, sub, event, set, mod, NULL); + return __ftrace_set_clr_event(tr, match, sub, event, set, mod, filter); } /** @@ -1593,7 +1604,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf, if (*parser.buffer == '!') set = 0; - ret = ftrace_set_clr_event(tr, parser.buffer + !set, set); + ret = ftrace_set_clr_event(tr, parser.buffer + !set, set, false); if (ret) goto out_put; } @@ -4842,10 +4853,10 @@ static __init void __early_set_events(struct trace_array *tr, char *buf, bool en while ((token = strsep(&buf, ","))) { if (*token) { if (enable) { - if (ftrace_set_clr_event(tr, token, 1)) + if (ftrace_set_clr_event(tr, token, 1, true)) pr_warn("Failed to enable trace event: %s\n", token); } else { - ftrace_set_clr_event(tr, token, 0); + ftrace_set_clr_event(tr, token, 0, true); } } diff --git a/kernel/trace/trace_events_test.c b/kernel/trace/trace_events_test.c index 515d2e668c31..4a2d77fa0f58 100644 --- a/kernel/trace/trace_events_test.c +++ b/kernel/trace/trace_events_test.c @@ -8,7 +8,7 @@ struct parse_event_string_test_case { const char *input; - const char *match, *sub, *event, *mod; + const char *match, *sub, *event, *mod, *filter; }; static const struct parse_event_string_test_case parse_event_string_test_cases[] = { @@ -37,6 +37,12 @@ static const struct parse_event_string_test_case parse_event_string_test_cases[] .sub = "sub", .event = "event", }, + { + "sub:event:filter:filter", + .sub = "sub", + .event = "event", + .filter = "filter", + }, { "match", .match = "match", @@ -51,6 +57,19 @@ static const struct parse_event_string_test_case parse_event_string_test_cases[] .event = "event", .mod = "module", }, + { + "sub:event:mod:module:filter:filter", + .sub = "sub", + .event = "event", + .mod = "module", + .filter = "filter", + }, + { + "sub:event:mod:module:filter:unexpected-filter", + .sub = "sub", + .event = "event", + .mod = "module:filter:unexpected-filter", + }, }; static void @@ -72,18 +91,19 @@ KUNIT_ARRAY_PARAM(parse_event_string, parse_event_string_test_cases, parse_event static void parse_event_string(struct kunit *test) { const struct parse_event_string_test_case *params = test->param_value; - char *input, *match, *sub, *event, *mod; + char *input, *match, *sub, *event, *mod, *filter; input = kunit_kstrdup(test, params->input, GFP_KERNEL); if (!input) kunit_skip(test, "ENOMEM"); - ftrace_parse_event_string(input, &match, &sub, &event, &mod); + ftrace_parse_event_string(input, &match, &sub, &event, &mod, params->filter, &filter); EXPECT_NULL_OR_STR_EQ(test, match, params->match); EXPECT_NULL_OR_STR_EQ(test, sub, params->sub); EXPECT_NULL_OR_STR_EQ(test, event, params->event); EXPECT_NULL_OR_STR_EQ(test, mod, params->mod); + EXPECT_NULL_OR_STR_EQ(test, filter, params->filter); } static struct kunit_case trace_events_test_cases[] = { -- 2.55.0