diff options
| -rw-r--r-- | kernel/trace/Kconfig | 9 | ||||
| -rw-r--r-- | kernel/trace/Makefile | 1 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 10 | ||||
| -rw-r--r-- | kernel/trace/trace_boot.c | 113 |
4 files changed, 128 insertions, 5 deletions
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); |