From patchwork Mon Dec 2 10:16:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 11268925 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3BA8B112B for ; Mon, 2 Dec 2019 10:16:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F790217D9 for ; Mon, 2 Dec 2019 10:16:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575281777; bh=FUVKNTbwYTZ1DLOiA4kcOk9dZe2xfMBYl7zgEEx3/PA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0P1DRHtjtsp7gDiPz49oYjZe5PzIaJkRE30kqwA7Hn4D0bbOHRvabEDhLlZN5lFVX DXzTgValhIdj3OtwF1Jv0I2gW+DKt8vesxSBY+cMrAw6c/KNgxbDjSp3RBjpiRYWLB HTOeRXG5cWXtLiLsYq5RY8bUmgocCLqBbe+MIawk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727699AbfLBKQO (ORCPT ); Mon, 2 Dec 2019 05:16:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:32886 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727433AbfLBKQN (ORCPT ); Mon, 2 Dec 2019 05:16:13 -0500 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A96A6215E5; Mon, 2 Dec 2019 10:16:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575281772; bh=FUVKNTbwYTZ1DLOiA4kcOk9dZe2xfMBYl7zgEEx3/PA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JUgGLswYzCXamieBo38CS+hXR+XwIz8lSmzZRN8kQUDeLa/U7sSnhlaHa4p07ZkKl YCqO7PLr985cZVnUuPm2O73FOTuyWmRuFFMZP8TkBHTpf0M3REciN4hqCll6k/6mHZ zyqXkF3Eipb7vc1asiaOWqwMZlD72uRO18MjUiDM= From: Masami Hiramatsu To: Steven Rostedt , Frank Rowand Cc: Ingo Molnar , Namhyung Kim , Tim Bird , Jiri Olsa , Arnaldo Carvalho de Melo , Tom Zanussi , Rob Herring , Andrew Morton , Thomas Gleixner , Greg Kroah-Hartman , Alexey Dobriyan , Jonathan Corbet , Linus Torvalds , linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v4 15/22] tracing/boot: Add boot-time tracing Date: Mon, 2 Dec 2019 19:16:06 +0900 Message-Id: <157528176637.22451.7632859779349327019.stgit@devnote2> X-Mailer: git-send-email 2.20.1 In-Reply-To: <157528159833.22451.14878731055438721716.stgit@devnote2> References: <157528159833.22451.14878731055438721716.stgit@devnote2> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Setup tracing options via extra boot config in addition to kernel command line. This adds following commands support. These are applied to the global trace instance. - ftrace.options = OPT1[,OPT2...] Enable given ftrace options. - ftrace.trace_clock = CLOCK Set given CLOCK to ftrace's trace_clock. - ftrace.buffer_size = SIZE Configure ftrace buffer size to SIZE. You can use "KB" or "MB" for that SIZE. - ftrace.events = EVENT[, EVENT2...] Enable given events on boot. You can use a wild card in EVENT. - ftrace.tracer = TRACER Set TRACER to current tracer on boot. (e.g. function) Note that this is NOT replacing the kernel parameters, because this boot config based setting is later than that. If you want to trace earlier boot events, you still need kernel parameters. Signed-off-by: Masami Hiramatsu --- Changes in v4: - Remove parameter which is not related to instance. - Use bootconfig. --- kernel/trace/Kconfig | 9 ++++ kernel/trace/Makefile | 1 kernel/trace/trace.c | 10 ++-- kernel/trace/trace_boot.c | 113 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 128 insertions(+), 5 deletions(-) create mode 100644 kernel/trace/trace_boot.c diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index cdf5afa87f65..1f133f1e0d12 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -805,6 +805,15 @@ config GCOV_PROFILE_FTRACE Note that on a kernel compiled with this config, ftrace will run significantly slower. +config BOOTTIME_TRACING + bool "Boot-time Tracing support" + depends on BOOT_CONFIG && TRACING + default y + help + Enable developer to setup ftrace subsystem via supplemental + kernel cmdline at boot time for debugging (tracing) driver + initialization and boot process. + endif # FTRACE endif # TRACING_SUPPORT diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index c2b2148bb1d2..f9d3c2c72fb5 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -82,6 +82,7 @@ endif obj-$(CONFIG_DYNAMIC_EVENTS) += trace_dynevent.o obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o obj-$(CONFIG_UPROBE_EVENTS) += trace_uprobe.o +obj-$(CONFIG_BOOTTIME_TRACING) += trace_boot.o obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index dbf57e9ae937..c19dce22f5bd 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -162,7 +162,7 @@ union trace_eval_map_item { static union trace_eval_map_item *trace_eval_maps; #endif /* CONFIG_TRACE_EVAL_MAP_FILE */ -static int tracing_set_tracer(struct trace_array *tr, const char *buf); +int tracing_set_tracer(struct trace_array *tr, const char *buf); static void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc); @@ -4737,7 +4737,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) return 0; } -static int trace_set_options(struct trace_array *tr, char *option) +int trace_set_options(struct trace_array *tr, char *option) { char *cmp; int neg = 0; @@ -5635,8 +5635,8 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, return ret; } -static ssize_t tracing_resize_ring_buffer(struct trace_array *tr, - unsigned long size, int cpu_id) +ssize_t tracing_resize_ring_buffer(struct trace_array *tr, + unsigned long size, int cpu_id) { int ret = size; @@ -5715,7 +5715,7 @@ static void add_tracer_options(struct trace_array *tr, struct tracer *t) create_trace_option_files(tr, t); } -static int tracing_set_tracer(struct trace_array *tr, const char *buf) +int tracing_set_tracer(struct trace_array *tr, const char *buf) { struct tracer *t; #ifdef CONFIG_TRACER_MAX_TRACE diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c new file mode 100644 index 000000000000..4b41310184df --- /dev/null +++ b/kernel/trace/trace_boot.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * trace_boot.c + * Tracing kernel boot-time + */ + +#define pr_fmt(fmt) "trace_boot: " fmt + +#include +#include +#include + +#include "trace.h" + +#define MAX_BUF_LEN 256 + +extern int trace_set_options(struct trace_array *tr, char *option); +extern int tracing_set_tracer(struct trace_array *tr, const char *buf); +extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr, + unsigned long size, int cpu_id); + +static void __init +trace_boot_set_ftrace_options(struct trace_array *tr, struct xbc_node *node) +{ + struct xbc_node *anode; + const char *p; + char buf[MAX_BUF_LEN]; + unsigned long v = 0; + + /* Common ftrace options */ + xbc_node_for_each_array_value(node, "options", anode, p) { + if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) { + pr_err("String is too long: %s\n", p); + continue; + } + + if (trace_set_options(tr, buf) < 0) + pr_err("Failed to set option: %s\n", buf); + } + + p = xbc_node_find_value(node, "trace_clock", NULL); + if (p && *p != '\0') { + if (tracing_set_clock(tr, p) < 0) + pr_err("Failed to set trace clock: %s\n", p); + } + + p = xbc_node_find_value(node, "buffer_size", NULL); + if (p && *p != '\0') { + v = memparse(p, NULL); + if (v < PAGE_SIZE) + pr_err("Buffer size is too small: %s\n", p); + if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0) + pr_err("Failed to resize trace buffer to %s\n", p); + } +} + +#ifdef CONFIG_EVENT_TRACING +extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set); + +static void __init +trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node) +{ + struct xbc_node *anode; + char buf[MAX_BUF_LEN]; + const char *p; + + xbc_node_for_each_array_value(node, "events", anode, p) { + if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) { + pr_err("String is too long: %s\n", p); + continue; + } + + if (ftrace_set_clr_event(tr, buf, 1) < 0) + pr_err("Failed to enable event: %s\n", p); + } +} +#else +#define trace_boot_enable_events(tr, node) do {} while (0) +#endif + +static void __init +trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node) +{ + const char *p; + + p = xbc_node_find_value(node, "tracer", NULL); + if (p && *p != '\0') { + if (tracing_set_tracer(tr, p) < 0) + pr_err("Failed to set given tracer: %s\n", p); + } +} + +static int __init trace_boot_init(void) +{ + struct xbc_node *trace_node; + struct trace_array *tr; + + trace_node = xbc_find_node("ftrace"); + if (!trace_node) + return 0; + + tr = top_trace_array(); + if (!tr) + return 0; + + trace_boot_set_ftrace_options(tr, trace_node); + trace_boot_enable_events(tr, trace_node); + trace_boot_enable_tracer(tr, trace_node); + + return 0; +} + +fs_initcall(trace_boot_init);