forked from Minki/linux
17abd7c36c
Add multiple histograms support for each event. This allows
user to set multiple histograms to an event.
ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] {
...
}
The 'N' is a digit started string and it can be omitted
for the default histogram.
For example, multiple hist triggers example in the
Documentation/trace/histogram.rst can be written as below;
ftrace.event.net.netif_receive_skb.hist {
1 {
keys = skbaddr.hex
values = len
filter = len < 0
}
2 {
keys = skbaddr.hex
values = len
filter = len > 4096
}
3 {
keys = skbaddr.hex
values = len
filter = len == 256
}
4 {
keys = skbaddr.hex
values = len
}
5 {
keys = len
values = common_preempt_count
}
}
Link: https://lkml.kernel.org/r/162856125628.203126.15846930277378572120.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
663 lines
16 KiB
C
663 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* trace_boot.c
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* Tracing kernel boot-time
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*/
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#define pr_fmt(fmt) "trace_boot: " fmt
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#include <linux/bootconfig.h>
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#include <linux/cpumask.h>
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#include <linux/ftrace.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/mutex.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/trace.h>
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#include <linux/trace_events.h>
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#include "trace.h"
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#define MAX_BUF_LEN 256
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static void __init
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trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
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{
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struct xbc_node *anode;
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const char *p;
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char buf[MAX_BUF_LEN];
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unsigned long v = 0;
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/* Common ftrace options */
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xbc_node_for_each_array_value(node, "options", anode, p) {
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if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
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pr_err("String is too long: %s\n", p);
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continue;
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}
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if (trace_set_options(tr, buf) < 0)
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pr_err("Failed to set option: %s\n", buf);
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}
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p = xbc_node_find_value(node, "tracing_on", NULL);
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if (p && *p != '\0') {
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if (kstrtoul(p, 10, &v))
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pr_err("Failed to set tracing on: %s\n", p);
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if (v)
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tracer_tracing_on(tr);
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else
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tracer_tracing_off(tr);
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}
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p = xbc_node_find_value(node, "trace_clock", NULL);
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if (p && *p != '\0') {
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if (tracing_set_clock(tr, p) < 0)
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pr_err("Failed to set trace clock: %s\n", p);
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}
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p = xbc_node_find_value(node, "buffer_size", NULL);
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if (p && *p != '\0') {
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v = memparse(p, NULL);
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if (v < PAGE_SIZE)
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pr_err("Buffer size is too small: %s\n", p);
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if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
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pr_err("Failed to resize trace buffer to %s\n", p);
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}
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p = xbc_node_find_value(node, "cpumask", NULL);
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if (p && *p != '\0') {
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cpumask_var_t new_mask;
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if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
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if (cpumask_parse(p, new_mask) < 0 ||
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tracing_set_cpumask(tr, new_mask) < 0)
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pr_err("Failed to set new CPU mask %s\n", p);
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free_cpumask_var(new_mask);
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}
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}
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}
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#ifdef CONFIG_EVENT_TRACING
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static void __init
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trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
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{
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struct xbc_node *anode;
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char buf[MAX_BUF_LEN];
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const char *p;
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xbc_node_for_each_array_value(node, "events", anode, p) {
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if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
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pr_err("String is too long: %s\n", p);
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continue;
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}
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if (ftrace_set_clr_event(tr, buf, 1) < 0)
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pr_err("Failed to enable event: %s\n", p);
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}
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}
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#ifdef CONFIG_KPROBE_EVENTS
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static int __init
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trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
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{
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struct dynevent_cmd cmd;
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struct xbc_node *anode;
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char buf[MAX_BUF_LEN];
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const char *val;
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int ret = 0;
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xbc_node_for_each_array_value(node, "probes", anode, val) {
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kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
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ret = kprobe_event_gen_cmd_start(&cmd, event, val);
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if (ret) {
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pr_err("Failed to generate probe: %s\n", buf);
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break;
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}
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ret = kprobe_event_gen_cmd_end(&cmd);
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if (ret) {
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pr_err("Failed to add probe: %s\n", buf);
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break;
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}
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}
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return ret;
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}
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#else
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static inline int __init
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trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
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{
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pr_err("Kprobe event is not supported.\n");
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return -ENOTSUPP;
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}
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#endif
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#ifdef CONFIG_SYNTH_EVENTS
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static int __init
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trace_boot_add_synth_event(struct xbc_node *node, const char *event)
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{
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struct dynevent_cmd cmd;
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struct xbc_node *anode;
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char buf[MAX_BUF_LEN];
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const char *p;
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int ret;
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synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
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ret = synth_event_gen_cmd_start(&cmd, event, NULL);
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if (ret)
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return ret;
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xbc_node_for_each_array_value(node, "fields", anode, p) {
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ret = synth_event_add_field_str(&cmd, p);
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if (ret)
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return ret;
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}
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ret = synth_event_gen_cmd_end(&cmd);
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if (ret < 0)
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pr_err("Failed to add synthetic event: %s\n", buf);
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return ret;
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}
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#else
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static inline int __init
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trace_boot_add_synth_event(struct xbc_node *node, const char *event)
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{
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pr_err("Synthetic event is not supported.\n");
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return -ENOTSUPP;
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}
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#endif
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#ifdef CONFIG_HIST_TRIGGERS
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static int __init __printf(3, 4)
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append_printf(char **bufp, char *end, const char *fmt, ...)
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{
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va_list args;
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int ret;
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if (*bufp == end)
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return -ENOSPC;
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va_start(args, fmt);
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ret = vsnprintf(*bufp, end - *bufp, fmt, args);
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if (ret < end - *bufp) {
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*bufp += ret;
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} else {
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*bufp = end;
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ret = -ERANGE;
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}
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va_end(args);
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return ret;
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}
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static int __init
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append_str_nospace(char **bufp, char *end, const char *str)
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{
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char *p = *bufp;
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int len;
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while (p < end - 1 && *str != '\0') {
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if (!isspace(*str))
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*(p++) = *str;
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str++;
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}
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*p = '\0';
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if (p == end - 1) {
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*bufp = end;
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return -ENOSPC;
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}
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len = p - *bufp;
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*bufp = p;
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return (int)len;
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}
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static int __init
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trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp,
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char *end, const char *key)
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{
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struct xbc_node *knode, *anode;
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const char *p;
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char sep;
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knode = xbc_node_find_child(hnode, key);
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if (knode) {
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anode = xbc_node_get_child(knode);
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if (!anode) {
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pr_err("hist.%s requires value(s).\n", key);
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return -EINVAL;
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}
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append_printf(bufp, end, ":%s", key);
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sep = '=';
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xbc_array_for_each_value(anode, p) {
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append_printf(bufp, end, "%c%s", sep, p);
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if (sep == '=')
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sep = ',';
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}
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} else
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return -ENOENT;
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return 0;
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}
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static int __init
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trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp,
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char *end, const char *handler,
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const char *param)
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{
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struct xbc_node *knode, *anode;
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const char *p;
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char sep;
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/* Compose 'handler' parameter */
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p = xbc_node_find_value(hnode, param, NULL);
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if (!p) {
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pr_err("hist.%s requires '%s' option.\n",
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xbc_node_get_data(hnode), param);
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return -EINVAL;
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}
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append_printf(bufp, end, ":%s(%s)", handler, p);
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/* Compose 'action' parameter */
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knode = xbc_node_find_child(hnode, "trace");
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if (!knode)
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knode = xbc_node_find_child(hnode, "save");
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if (knode) {
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anode = xbc_node_get_child(knode);
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if (!anode || !xbc_node_is_value(anode)) {
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pr_err("hist.%s.%s requires value(s).\n",
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xbc_node_get_data(hnode),
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xbc_node_get_data(knode));
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return -EINVAL;
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}
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append_printf(bufp, end, ".%s", xbc_node_get_data(knode));
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sep = '(';
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xbc_array_for_each_value(anode, p) {
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append_printf(bufp, end, "%c%s", sep, p);
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if (sep == '(')
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sep = ',';
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}
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append_printf(bufp, end, ")");
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} else if (xbc_node_find_child(hnode, "snapshot")) {
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append_printf(bufp, end, ".snapshot()");
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} else {
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pr_err("hist.%s requires an action.\n",
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xbc_node_get_data(hnode));
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return -EINVAL;
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}
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return 0;
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}
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static int __init
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trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp,
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char *end, const char *param)
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{
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struct xbc_node *node;
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const char *p, *handler;
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int ret;
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handler = xbc_node_get_data(hnode);
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xbc_node_for_each_subkey(hnode, node) {
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p = xbc_node_get_data(node);
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if (!isdigit(p[0]))
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continue;
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/* All digit started node should be instances. */
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ret = trace_boot_hist_add_one_handler(node, bufp, end, handler, param);
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if (ret < 0)
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break;
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}
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if (xbc_node_find_child(hnode, param))
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ret = trace_boot_hist_add_one_handler(hnode, bufp, end, handler, param);
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return ret;
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}
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/*
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* Histogram boottime tracing syntax.
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*
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* ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] {
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* keys = <KEY>[,...]
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* values = <VAL>[,...]
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* sort = <SORT-KEY>[,...]
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* size = <ENTRIES>
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* name = <HISTNAME>
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* var { <VAR> = <EXPR> ... }
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* pause|continue|clear
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* onmax|onchange[.N] { var = <VAR>; <ACTION> [= <PARAM>] }
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* onmatch[.N] { event = <EVENT>; <ACTION> [= <PARAM>] }
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* filter = <FILTER>
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* }
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*
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* Where <ACTION> are;
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*
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* trace = <EVENT>, <ARG1>[, ...]
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* save = <ARG1>[, ...]
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* snapshot
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*/
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static int __init
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trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size)
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{
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struct xbc_node *node, *knode;
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char *end = buf + size;
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const char *p;
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int ret = 0;
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append_printf(&buf, end, "hist");
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ret = trace_boot_hist_add_array(hnode, &buf, end, "keys");
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if (ret < 0) {
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if (ret == -ENOENT)
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pr_err("hist requires keys.\n");
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return -EINVAL;
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}
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ret = trace_boot_hist_add_array(hnode, &buf, end, "values");
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if (ret == -EINVAL)
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return ret;
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ret = trace_boot_hist_add_array(hnode, &buf, end, "sort");
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if (ret == -EINVAL)
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return ret;
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p = xbc_node_find_value(hnode, "size", NULL);
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if (p)
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append_printf(&buf, end, ":size=%s", p);
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p = xbc_node_find_value(hnode, "name", NULL);
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if (p)
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append_printf(&buf, end, ":name=%s", p);
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node = xbc_node_find_child(hnode, "var");
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if (node) {
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xbc_node_for_each_key_value(node, knode, p) {
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/* Expression must not include spaces. */
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append_printf(&buf, end, ":%s=",
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xbc_node_get_data(knode));
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append_str_nospace(&buf, end, p);
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}
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}
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/* Histogram control attributes (mutual exclusive) */
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if (xbc_node_find_child(hnode, "pause"))
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append_printf(&buf, end, ":pause");
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else if (xbc_node_find_child(hnode, "continue"))
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append_printf(&buf, end, ":continue");
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else if (xbc_node_find_child(hnode, "clear"))
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append_printf(&buf, end, ":clear");
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/* Histogram handler and actions */
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node = xbc_node_find_child(hnode, "onmax");
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if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0)
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return -EINVAL;
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node = xbc_node_find_child(hnode, "onchange");
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if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0)
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return -EINVAL;
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node = xbc_node_find_child(hnode, "onmatch");
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if (node && trace_boot_hist_add_handlers(node, &buf, end, "event") < 0)
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return -EINVAL;
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p = xbc_node_find_value(hnode, "filter", NULL);
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if (p)
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append_printf(&buf, end, " if %s", p);
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if (buf == end) {
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pr_err("hist exceeds the max command length.\n");
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return -E2BIG;
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}
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return 0;
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}
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static void __init
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trace_boot_init_histograms(struct trace_event_file *file,
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struct xbc_node *hnode, char *buf, size_t size)
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{
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struct xbc_node *node;
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const char *p;
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xbc_node_for_each_subkey(hnode, node) {
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p = xbc_node_get_data(node);
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if (!isdigit(p[0]))
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continue;
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/* All digit started node should be instances. */
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if (trace_boot_compose_hist_cmd(node, buf, size) == 0) {
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if (trigger_process_regex(file, buf) < 0)
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pr_err("Failed to apply hist trigger: %s\n", buf);
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}
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}
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if (xbc_node_find_child(hnode, "keys")) {
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if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0)
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if (trigger_process_regex(file, buf) < 0)
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pr_err("Failed to apply hist trigger: %s\n", buf);
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}
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}
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#else
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static void __init
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trace_boot_init_histograms(struct trace_event_file *file,
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struct xbc_node *hnode, char *buf, size_t size)
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{
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/* do nothing */
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}
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#endif
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static void __init
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trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
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struct xbc_node *enode)
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{
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struct trace_event_file *file;
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struct xbc_node *anode;
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char buf[MAX_BUF_LEN];
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const char *p, *group, *event;
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group = xbc_node_get_data(gnode);
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event = xbc_node_get_data(enode);
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if (!strcmp(group, "kprobes"))
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if (trace_boot_add_kprobe_event(enode, event) < 0)
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return;
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if (!strcmp(group, "synthetic"))
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if (trace_boot_add_synth_event(enode, event) < 0)
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return;
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mutex_lock(&event_mutex);
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file = find_event_file(tr, group, event);
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if (!file) {
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pr_err("Failed to find event: %s:%s\n", group, event);
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goto out;
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}
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p = xbc_node_find_value(enode, "filter", NULL);
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if (p && *p != '\0') {
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if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
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pr_err("filter string is too long: %s\n", p);
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else if (apply_event_filter(file, buf) < 0)
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pr_err("Failed to apply filter: %s\n", buf);
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}
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if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) {
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xbc_node_for_each_array_value(enode, "actions", anode, p) {
|
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if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
|
|
pr_err("action string is too long: %s\n", p);
|
|
else if (trigger_process_regex(file, buf) < 0)
|
|
pr_err("Failed to apply an action: %s\n", buf);
|
|
}
|
|
anode = xbc_node_find_child(enode, "hist");
|
|
if (anode)
|
|
trace_boot_init_histograms(file, anode, buf, ARRAY_SIZE(buf));
|
|
} else if (xbc_node_find_value(enode, "actions", NULL))
|
|
pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n");
|
|
|
|
if (xbc_node_find_value(enode, "enable", NULL)) {
|
|
if (trace_event_enable_disable(file, 1, 0) < 0)
|
|
pr_err("Failed to enable event node: %s:%s\n",
|
|
group, event);
|
|
}
|
|
out:
|
|
mutex_unlock(&event_mutex);
|
|
}
|
|
|
|
static void __init
|
|
trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
|
|
{
|
|
struct xbc_node *gnode, *enode;
|
|
bool enable, enable_all = false;
|
|
const char *data;
|
|
|
|
node = xbc_node_find_child(node, "event");
|
|
if (!node)
|
|
return;
|
|
/* per-event key starts with "event.GROUP.EVENT" */
|
|
xbc_node_for_each_child(node, gnode) {
|
|
data = xbc_node_get_data(gnode);
|
|
if (!strcmp(data, "enable")) {
|
|
enable_all = true;
|
|
continue;
|
|
}
|
|
enable = false;
|
|
xbc_node_for_each_child(gnode, enode) {
|
|
data = xbc_node_get_data(enode);
|
|
if (!strcmp(data, "enable")) {
|
|
enable = true;
|
|
continue;
|
|
}
|
|
trace_boot_init_one_event(tr, gnode, enode);
|
|
}
|
|
/* Event enablement must be done after event settings */
|
|
if (enable) {
|
|
data = xbc_node_get_data(gnode);
|
|
trace_array_set_clr_event(tr, data, NULL, true);
|
|
}
|
|
}
|
|
/* Ditto */
|
|
if (enable_all)
|
|
trace_array_set_clr_event(tr, NULL, NULL, true);
|
|
}
|
|
#else
|
|
#define trace_boot_enable_events(tr, node) do {} while (0)
|
|
#define trace_boot_init_events(tr, node) do {} while (0)
|
|
#endif
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
static void __init
|
|
trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
|
|
{
|
|
struct xbc_node *anode;
|
|
const char *p;
|
|
char *q;
|
|
|
|
xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
|
|
q = kstrdup(p, GFP_KERNEL);
|
|
if (!q)
|
|
return;
|
|
if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
|
|
pr_err("Failed to add %s to ftrace filter\n", p);
|
|
else
|
|
ftrace_filter_param = true;
|
|
kfree(q);
|
|
}
|
|
xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
|
|
q = kstrdup(p, GFP_KERNEL);
|
|
if (!q)
|
|
return;
|
|
if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
|
|
pr_err("Failed to add %s to ftrace filter\n", p);
|
|
else
|
|
ftrace_filter_param = true;
|
|
kfree(q);
|
|
}
|
|
}
|
|
#else
|
|
#define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
|
|
#endif
|
|
|
|
static void __init
|
|
trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
|
|
{
|
|
const char *p;
|
|
|
|
trace_boot_set_ftrace_filter(tr, node);
|
|
|
|
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);
|
|
}
|
|
|
|
/* Since tracer can free snapshot buffer, allocate snapshot here.*/
|
|
if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
|
|
if (tracing_alloc_snapshot_instance(tr) < 0)
|
|
pr_err("Failed to allocate snapshot buffer\n");
|
|
}
|
|
}
|
|
|
|
static void __init
|
|
trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
|
|
{
|
|
trace_boot_set_instance_options(tr, node);
|
|
trace_boot_init_events(tr, node);
|
|
trace_boot_enable_events(tr, node);
|
|
trace_boot_enable_tracer(tr, node);
|
|
}
|
|
|
|
static void __init
|
|
trace_boot_init_instances(struct xbc_node *node)
|
|
{
|
|
struct xbc_node *inode;
|
|
struct trace_array *tr;
|
|
const char *p;
|
|
|
|
node = xbc_node_find_child(node, "instance");
|
|
if (!node)
|
|
return;
|
|
|
|
xbc_node_for_each_child(node, inode) {
|
|
p = xbc_node_get_data(inode);
|
|
if (!p || *p == '\0')
|
|
continue;
|
|
|
|
tr = trace_array_get_by_name(p);
|
|
if (!tr) {
|
|
pr_err("Failed to get trace instance %s\n", p);
|
|
continue;
|
|
}
|
|
trace_boot_init_one_instance(tr, inode);
|
|
trace_array_put(tr);
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
/* Global trace array is also one instance */
|
|
trace_boot_init_one_instance(tr, trace_node);
|
|
trace_boot_init_instances(trace_node);
|
|
|
|
disable_tracing_selftest("running boot-time tracing");
|
|
|
|
return 0;
|
|
}
|
|
/*
|
|
* Start tracing at the end of core-initcall, so that it starts tracing
|
|
* from the beginning of postcore_initcall.
|
|
*/
|
|
core_initcall_sync(trace_boot_init);
|