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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Masami Hiramatsu <mhiramat@kernel.org>
Subject: [for-next][PATCH 18/26] tracing/boot: Add boot-time tracing
Date: Tue, 14 Jan 2020 16:03:34 -0500	[thread overview]
Message-ID: <20200114210338.325622787@goodmis.org> (raw)
In-Reply-To: <20200114210316.450821675@goodmis.org>

From: Masami Hiramatsu <mhiramat@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.

Link: http://lkml.kernel.org/r/157867237723.17873.17494943526320587488.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 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 25a0fcfa7a5d..75326d8ab1af 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -814,6 +814,15 @@ 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 0e63db62225f..395e2db9c742 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -83,6 +83,7 @@ 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 cb850d2c4bfa..6c996d1b1687 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 trace_buffer *buffer,
 				   unsigned long flags, int pc);
 
@@ -4747,7 +4747,7 @@ 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;
@@ -5647,8 +5647,8 @@ 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;
 
@@ -5727,7 +5727,7 @@ 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 <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/bootconfig.h>
+
+#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);
-- 
2.24.1



  parent reply	other threads:[~2020-01-14 21:03 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-14 21:03 [for-next][PATCH 00/26] tracing: Updates for 5.6 Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 01/26] perf: Make struct ring_buffer less ambiguous Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 02/26] tracing: Rename trace_buffer to array_buffer Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 03/26] tracing: Make struct ring_buffer less ambiguous Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 04/26] bootconfig: Add Extra Boot Config support Steven Rostedt
2020-02-06 11:54   ` Borislav Petkov
2020-02-06 14:41     ` Masami Hiramatsu
2020-02-06 17:20       ` Geert Uytterhoeven
2020-02-07  0:30         ` Masami Hiramatsu
2020-02-07  8:49           ` Geert Uytterhoeven
2020-02-07 13:17             ` Masami Hiramatsu
2020-02-07 14:28               ` [PATCH] bootconfig: Allocate xbc_nodes array dynamically Masami Hiramatsu
2020-02-06 17:58       ` [for-next][PATCH 04/26] bootconfig: Add Extra Boot Config support Borislav Petkov
2020-02-06 18:10         ` Randy Dunlap
2020-02-06 22:39           ` Steven Rostedt
2020-02-06 22:51             ` Borislav Petkov
2020-02-07  8:59             ` Geert Uytterhoeven
2020-02-07  2:46         ` Masami Hiramatsu
2020-02-07 11:41           ` Borislav Petkov
2020-02-07 15:06             ` Masami Hiramatsu
2020-02-10 11:25               ` Borislav Petkov
2020-02-10 15:10                 ` Masami Hiramatsu
2020-02-10 17:40                   ` Borislav Petkov
2020-02-11  2:02                     ` Masami Hiramatsu
2020-02-18 13:27                       ` Borislav Petkov
2020-02-18 17:57                         ` Steven Rostedt
2020-02-18 19:38                           ` Borislav Petkov
2020-02-19  2:26                             ` Masami Hiramatsu
2020-02-19  2:26                           ` Masami Hiramatsu
2020-02-19  2:26                         ` Masami Hiramatsu
2020-02-11  9:25                     ` Geert Uytterhoeven
2020-01-14 21:03 ` [for-next][PATCH 05/26] bootconfig: Load boot config from the tail of initrd Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 06/26] tools: bootconfig: Add bootconfig command Steven Rostedt
2020-02-07 13:02   ` Michael Ellerman
2020-02-07 13:39     ` Masami Hiramatsu
2020-02-07 13:55     ` [PATCH] tools/bootconfig: Fix wrong __VA_ARGS__ usage Masami Hiramatsu
2020-02-08 11:10       ` Michael Ellerman
2020-02-09  4:09         ` Masami Hiramatsu
2020-02-09 13:05         ` [PATCH] tools/bootconfig: Suppress non-error messages Masami Hiramatsu
2020-02-10  2:06           ` Michael Ellerman
2020-02-10  7:18             ` Masami Hiramatsu
2020-02-10  9:50               ` Michael Ellerman
2020-02-10  9:50       ` [PATCH] tools/bootconfig: Fix wrong __VA_ARGS__ usage Michael Ellerman
2020-02-10 17:07         ` Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 07/26] tools: bootconfig: Add bootconfig test script Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 08/26] proc: bootconfig: Add /proc/bootconfig to show boot config list Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 09/26] init/main.c: Alloc initcall_command_line in do_initcall() and free it Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 10/26] bootconfig: init: Allow admin to use bootconfig for kernel command line Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 11/26] bootconfig: init: Allow admin to use bootconfig for init " Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 12/26] Documentation: bootconfig: Add a doc for extended boot config Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 13/26] tracing: Apply soft-disabled and filter to tracepoints printk Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 14/26] tracing: kprobes: Output kprobe event to printk buffer Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 15/26] tracing: kprobes: Register to dynevent earlier stage Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 16/26] tracing: Accept different type for synthetic event fields Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 17/26] tracing: Add NULL trace-array check in print_synth_event() Steven Rostedt
2020-01-14 21:03 ` Steven Rostedt [this message]
2020-01-14 21:03 ` [for-next][PATCH 19/26] tracing/boot: Add per-event settings Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 20/26] tracing/boot Add kprobe event support Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 21/26] tracing/boot: Add synthetic " Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 22/26] tracing/boot: Add instance node support Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 23/26] tracing/boot: Add cpu_mask option support Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 24/26] tracing/boot: Add function tracer filter options Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 25/26] Documentation: tracing: Add boot-time tracing document Steven Rostedt
2020-01-14 21:03 ` [for-next][PATCH 26/26] tracing: trigger: Replace unneeded RCU-list traversals Steven Rostedt
2020-01-14 22:11   ` Steven Rostedt

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