From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout02.his.huawei.com (canpmsgout02.his.huawei.com [113.46.200.217]) (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 75BD32F8E99; Fri, 8 May 2026 12:32:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.217 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778243535; cv=none; b=KHVB+WQTgh9U7ODwEDuVByrxupwYrISg82uuU+H18IEl12TLMvP5pqjhTpxH2ogqLpcTZdSCXpigvQhUmY/fGtDXs7U7/oS3jNYTC9wteG14GIYqlT00+2jRCfNH6Gp198hDtZXXyzy7mqhuTi8R7iaREB++0CB7ye+spXAcW+0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778243535; c=relaxed/simple; bh=plfyk/TrAz40I93O4nh1R71kQdghuovb5in/6BPamUI=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=hV7yqf7ddfmKU3QecDtKpyPdIeu4YxKE2TiLlC5Rrori6O45ThRvQvpMpeic2JbdQjVp3tnE6PNa4Y5XMM9SRTf3TAODsEokGPgrgkfbYjJKirRMbITMpY7W8IRdqhbdBtFt+F4TtH5cOI+IDlW/yKgRHnpAUN1L7sx7V+cqzOY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=Zq+JYcrS; arc=none smtp.client-ip=113.46.200.217 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="Zq+JYcrS" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=fCGrgN0EMikwS3Zxxo/jIhUp30pLmtvgsNzlpXGk82A=; b=Zq+JYcrSpr0zoIv6yOn3HSjRG63nuKglJP5H9/kERhsYdTq1FP6wA0FOEblak3HPVATz7amqj fAxJ9leN0tf/DQRToAYEFUhW7CHm/st5/iP0WFElUiq83Yfqi7dcYcKJT3h5RSu85ELgLdADOac 2rtUqrGh/A+n/Z+ihzJ2Hi0= Received: from mail.maildlp.com (unknown [172.19.162.197]) by canpmsgout02.his.huawei.com (SkyGuard) with ESMTPS id 4gBpGb6PmhzcZyh; Fri, 8 May 2026 20:24:55 +0800 (CST) Received: from dggpemf100008.china.huawei.com (unknown [7.185.36.138]) by mail.maildlp.com (Postfix) with ESMTPS id 4E99240569; Fri, 8 May 2026 20:32:08 +0800 (CST) Received: from mdc.huawei.com (10.50.87.204) by dggpemf100008.china.huawei.com (7.185.36.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 8 May 2026 20:32:07 +0800 From: Chen Jun To: , , , , CC: Subject: [RFC PATCH] trace: Introduce a new filter_pred "caller" Date: Fri, 8 May 2026 20:26:23 +0800 Message-ID: <20260508122623.74290-1-chenjun102@huawei.com> X-Mailer: git-send-email 2.22.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: kwepems100001.china.huawei.com (7.221.188.238) To dggpemf100008.china.huawei.com (7.185.36.138) Low-level functions have many call paths, and sometimes we only care about the calls on a specific call path. Add a new filter to filter based on the call stack. Usage: 1. echo 'caller=="$function_name"' > events/../filter Only support OP_EQ and OP_NE Signed-off-by: Chen Jun --- include/linux/trace_events.h | 1 + kernel/trace/trace.h | 3 ++- kernel/trace/trace_events.c | 1 + kernel/trace/trace_events_filter.c | 40 ++++++++++++++++++++++++++++-- 4 files changed, 42 insertions(+), 3 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 40a43a4c7caf..1f109669a391 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -851,6 +851,7 @@ enum { FILTER_COMM, FILTER_CPU, FILTER_STACKTRACE, + FILTER_CALLER, }; extern int trace_event_raw_init(struct trace_event_call *call); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 80fe152af1dd..4e4b92ce264f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1825,7 +1825,8 @@ static inline bool is_string_field(struct ftrace_event_field *field) field->filter_type == FILTER_RDYN_STRING || field->filter_type == FILTER_STATIC_STRING || field->filter_type == FILTER_PTR_STRING || - field->filter_type == FILTER_COMM; + field->filter_type == FILTER_COMM || + field->filter_type == FILTER_CALLER; } static inline bool is_function_field(struct ftrace_event_field *field) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index c46e623e7e0d..6d220d7eec73 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -199,6 +199,7 @@ static int trace_define_generic_fields(void) __generic_field(char *, comm, FILTER_COMM); __generic_field(char *, stacktrace, FILTER_STACKTRACE); __generic_field(char *, STACKTRACE, FILTER_STACKTRACE); + __generic_field(char *, caller, FILTER_CALLER); return ret; } diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 609325f57942..1cf040065abe 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -72,6 +72,7 @@ enum filter_pred_fn { FILTER_PRED_FN_CPUMASK, FILTER_PRED_FN_CPUMASK_CPU, FILTER_PRED_FN_FUNCTION, + FILTER_PRED_FN_CALLER, FILTER_PRED_FN_, FILTER_PRED_TEST_VISITED, }; @@ -1009,6 +1010,21 @@ static int filter_pred_function(struct filter_pred *pred, void *event) return pred->op == OP_EQ ? ret : !ret; } +/* Filter predicate for caller. */ +static int filter_pred_caller(struct filter_pred *pred, void *event) +{ + unsigned long entries[32]; + unsigned int nr_entries; + int i; + + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); + for (i = 0; i < nr_entries ; i++) + if (pred->val <= entries[i] && entries[i] < pred->val2) + return !pred->not; + + return pred->not; +} + /* * regex_match_foo - Basic regex callbacks * @@ -1617,6 +1633,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event) return filter_pred_cpumask_cpu(pred, event); case FILTER_PRED_FN_FUNCTION: return filter_pred_function(pred, event); + case FILTER_PRED_FN_CALLER: + return filter_pred_caller(pred, event); case FILTER_PRED_TEST_VISITED: return test_pred_visited_fn(pred, event); default: @@ -2002,10 +2020,28 @@ static int parse_pred(const char *str, void *data, } else if (field->filter_type == FILTER_DYN_STRING) { pred->fn_num = FILTER_PRED_FN_STRLOC; - } else if (field->filter_type == FILTER_RDYN_STRING) + } else if (field->filter_type == FILTER_RDYN_STRING) { pred->fn_num = FILTER_PRED_FN_STRRELLOC; - else { + } else if (field->filter_type == FILTER_CALLER) { + unsigned long caller; + + if (op == OP_GLOB) + goto err_free; + pred->fn_num = FILTER_PRED_FN_CALLER; + caller = kallsyms_lookup_name(pred->regex->pattern); + if (!caller) { + parse_error(pe, FILT_ERR_NO_FUNCTION, pos + i); + goto err_free; + } + /* Now find the function start and end address */ + if (!kallsyms_lookup_size_offset(caller, &size, &offset)) { + parse_error(pe, FILT_ERR_NO_FUNCTION, pos + i); + goto err_free; + } + pred->val = caller - offset; + pred->val2 = pred->val + size; + } else { if (!ustring_per_cpu) { /* Once allocated, keep it around for good */ ustring_per_cpu = alloc_percpu(struct ustring_buffer); -- 2.22.0