#define pr_fmt(fmt) "trace_boot: " fmt
#include <linux/bootconfig.h>
#include <linux/cpumask.h>
#include <linux/ftrace.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/trace.h>
#include <linux/trace_events.h>
#include "trace.h"
#define MAX_BUF_LEN 256
static void __init
trace_boot_set_instance_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;
xbc_node_for_each_array_value(node, "options", anode, p) {
if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) {
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, "tracing_on", NULL);
if (p && *p != '\0') {
if (kstrtoul(p, 10, &v))
pr_err("Failed to set tracing on: %s\n", p);
if (v)
tracer_tracing_on(tr);
else
tracer_tracing_off(tr);
}
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);
}
p = xbc_node_find_value(node, "cpumask", NULL);
if (p && *p != '\0') {
cpumask_var_t new_mask;
if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
if (cpumask_parse(p, new_mask) < 0 ||
tracing_set_cpumask(tr, new_mask) < 0)
pr_err("Failed to set new CPU mask %s\n", p);
free_cpumask_var(new_mask);
}
}
}
#ifdef CONFIG_EVENT_TRACING
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 (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) {
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);
}
}
#ifdef CONFIG_KPROBE_EVENTS
static int __init
trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
{
struct dynevent_cmd cmd;
struct xbc_node *anode;
char buf[MAX_BUF_LEN];
const char *val;
int ret = 0;
xbc_node_for_each_array_value(node, "probes", anode, val) {
kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
ret = kprobe_event_gen_cmd_start(&cmd, event, val);
if (ret) {
pr_err("Failed to generate probe: %s\n", buf);
break;
}
ret = kprobe_event_gen_cmd_end(&cmd);
if (ret) {
pr_err("Failed to add probe: %s\n", buf);
break;
}
}
return ret;
}
#else
static inline int __init
trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
{
pr_err("Kprobe event is not supported.\n");
return -ENOTSUPP;
}
#endif
#ifdef CONFIG_SYNTH_EVENTS
static int __init
trace_boot_add_synth_event(struct xbc_node *node, const char *event)
{
struct dynevent_cmd cmd;
struct xbc_node *anode;
char buf[MAX_BUF_LEN];
const char *p;
int ret;
synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
ret = synth_event_gen_cmd_start(&cmd, event, NULL);
if (ret)
return ret;
xbc_node_for_each_array_value(node, "fields", anode, p) {
ret = synth_event_add_field_str(&cmd, p);
if (ret)
return ret;
}
ret = synth_event_gen_cmd_end(&cmd);
if (ret < 0)
pr_err("Failed to add synthetic event: %s\n", buf);
return ret;
}
#else
static inline int __init
trace_boot_add_synth_event(struct xbc_node *node, const char *event)
{
pr_err("Synthetic event is not supported.\n");
return -ENOTSUPP;
}
#endif
#ifdef CONFIG_HIST_TRIGGERS
static int __init __printf(3, 4)
append_printf(char **bufp, char *end, const char *fmt, ...)
{
va_list args;
int ret;
if (*bufp == end)
return -ENOSPC;
va_start(args, fmt);
ret = vsnprintf(*bufp, end - *bufp, fmt, args);
if (ret < end - *bufp) {
*bufp += ret;
} else {
*bufp = end;
ret = -ERANGE;
}
va_end(args);
return ret;
}
static int __init
append_str_nospace(char **bufp, char *end, const char *str)
{
char *p = *bufp;
int len;
while (p < end - 1 && *str != '\0') {
if (!isspace(*str))
*(p++) = *str;
str++;
}
*p = '\0';
if (p == end - 1) {
*bufp = end;
return -ENOSPC;
}
len = p - *bufp;
*bufp = p;
return (int)len;
}
static int __init
trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp,
char *end, const char *key)
{
struct xbc_node *anode;
const char *p;
char sep;
p = xbc_node_find_value(hnode, key, &anode);
if (p) {
if (!anode) {
pr_err("hist.%s requires value(s).\n", key);
return -EINVAL;
}
append_printf(bufp, end, ":%s", key);
sep = '=';
xbc_array_for_each_value(anode, p) {
append_printf(bufp, end, "%c%s", sep, p);
if (sep == '=')
sep = ',';
}
} else
return -ENOENT;
return 0;
}
static int __init
trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp,
char *end, const char *handler,
const char *param)
{
struct xbc_node *knode, *anode;
const char *p;
char sep;
p = xbc_node_find_value(hnode, param, NULL);
if (!p) {
pr_err("hist.%s requires '%s' option.\n",
xbc_node_get_data(hnode), param);
return -EINVAL;
}
append_printf(bufp, end, ":%s(%s)", handler, p);
knode = xbc_node_find_subkey(hnode, "trace");
if (!knode)
knode = xbc_node_find_subkey(hnode, "save");
if (knode) {
anode = xbc_node_get_child(knode);
if (!anode || !xbc_node_is_value(anode)) {
pr_err("hist.%s.%s requires value(s).\n",
xbc_node_get_data(hnode),
xbc_node_get_data(knode));
return -EINVAL;
}
append_printf(bufp, end, ".%s", xbc_node_get_data(knode));
sep = '(';
xbc_array_for_each_value(anode, p) {
append_printf(bufp, end, "%c%s", sep, p);
if (sep == '(')
sep = ',';
}
append_printf(bufp, end, ")");
} else if (xbc_node_find_subkey(hnode, "snapshot")) {
append_printf(bufp, end, ".snapshot()");
} else {
pr_err("hist.%s requires an action.\n",
xbc_node_get_data(hnode));
return -EINVAL;
}
return 0;
}
static int __init
trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp,
char *end, const char *param)
{
struct xbc_node *node;
const char *p, *handler;
int ret = 0;
handler = xbc_node_get_data(hnode);
xbc_node_for_each_subkey(hnode, node) {
p = xbc_node_get_data(node);
if (!isdigit(p[0]))
continue;
ret = trace_boot_hist_add_one_handler(node, bufp, end, handler, param);
if (ret < 0)
break;
}
if (xbc_node_find_subkey(hnode, param))
ret = trace_boot_hist_add_one_handler(hnode, bufp, end, handler, param);
return ret;
}
static int __init
trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size)
{
struct xbc_node *node, *knode;
char *end = buf + size;
const char *p;
int ret = 0;
append_printf(&buf, end, "hist");
ret = trace_boot_hist_add_array(hnode, &buf, end, "keys");
if (ret < 0) {
if (ret == -ENOENT)
pr_err("hist requires keys.\n");
return -EINVAL;
}
ret = trace_boot_hist_add_array(hnode, &buf, end, "values");
if (ret == -EINVAL)
return ret;
ret = trace_boot_hist_add_array(hnode, &buf, end, "sort");
if (ret == -EINVAL)
return ret;
p = xbc_node_find_value(hnode, "size", NULL);
if (p)
append_printf(&buf, end, ":size=%s", p);
p = xbc_node_find_value(hnode, "name", NULL);
if (p)
append_printf(&buf, end, ":name=%s", p);
node = xbc_node_find_subkey(hnode, "var");
if (node) {
xbc_node_for_each_key_value(node, knode, p) {
append_printf(&buf, end, ":%s=",
xbc_node_get_data(knode));
append_str_nospace(&buf, end, p);
}
}
if (xbc_node_find_value(hnode, "pause", NULL))
append_printf(&buf, end, ":pause");
else if (xbc_node_find_value(hnode, "continue", NULL))
append_printf(&buf, end, ":continue");
else if (xbc_node_find_value(hnode, "clear", NULL))
append_printf(&buf, end, ":clear");
node = xbc_node_find_subkey(hnode, "onmax");
if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0)
return -EINVAL;
node = xbc_node_find_subkey(hnode, "onchange");
if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0)
return -EINVAL;
node = xbc_node_find_subkey(hnode, "onmatch");
if (node && trace_boot_hist_add_handlers(node, &buf, end, "event") < 0)
return -EINVAL;
p = xbc_node_find_value(hnode, "filter", NULL);
if (p)
append_printf(&buf, end, " if %s", p);
if (buf == end) {
pr_err("hist exceeds the max command length.\n");
return -E2BIG;
}
return 0;
}
static void __init
trace_boot_init_histograms(struct trace_event_file *file,
struct xbc_node *hnode, char *buf, size_t size)
{
struct xbc_node *node;
const char *p;
char *tmp;
xbc_node_for_each_subkey(hnode, node) {
p = xbc_node_get_data(node);
if (!isdigit(p[0]))
continue;
if (trace_boot_compose_hist_cmd(node, buf, size) == 0) {
tmp = kstrdup(buf, GFP_KERNEL);
if (!tmp)
return;
if (trigger_process_regex(file, buf) < 0)
pr_err("Failed to apply hist trigger: %s\n", tmp);
kfree(tmp);
}
}
if (xbc_node_find_subkey(hnode, "keys")) {
if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0) {
tmp = kstrdup(buf, GFP_KERNEL);
if (!tmp)
return;
if (trigger_process_regex(file, buf) < 0)
pr_err("Failed to apply hist trigger: %s\n", tmp);
kfree(tmp);
}
}
}
#else
static void __init
trace_boot_init_histograms(struct trace_event_file *file,
struct xbc_node *hnode, char *buf, size_t size)
{
}
#endif
static void __init
trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
struct xbc_node *enode)
{
struct trace_event_file *file;
struct xbc_node *anode;
char buf[MAX_BUF_LEN];
const char *p, *group, *event;
group = xbc_node_get_data(gnode);
event = xbc_node_get_data(enode);
if (!strcmp(group, "kprobes"))
if (trace_boot_add_kprobe_event(enode, event) < 0)
return;
if (!strcmp(group, "synthetic"))
if (trace_boot_add_synth_event(enode, event) < 0)
return;
mutex_lock(&event_mutex);
file = find_event_file(tr, group, event);
if (!file) {
pr_err("Failed to find event: %s:%s\n", group, event);
goto out;
}
p = xbc_node_find_value(enode, "filter", NULL);
if (p && *p != '\0') {
if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0)
pr_err("filter string is too long: %s\n", p);
else if (apply_event_filter(file, buf) < 0)
pr_err("Failed to apply filter: %s\n", buf);
}
if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) {
xbc_node_for_each_array_value(enode, "actions", anode, p) {
if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0)
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", p);
}
anode = xbc_node_find_subkey(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_subkey(node, "event");
if (!node)
return;
xbc_node_for_each_subkey(node, gnode) {
data = xbc_node_get_data(gnode);
if (!strcmp(data, "enable")) {
enable_all = true;
continue;
}
enable = false;
xbc_node_for_each_subkey(gnode, enode) {
data = xbc_node_get_data(enode);
if (!strcmp(data, "enable")) {
enable = true;
continue;
}
trace_boot_init_one_event(tr, gnode, enode);
}
if (enable) {
data = xbc_node_get_data(gnode);
trace_array_set_clr_event(tr, data, NULL, true);
}
}
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);
}
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_subkey(node, "instance");
if (!node)
return;
xbc_node_for_each_subkey(node, inode) {
p = xbc_node_get_data(inode);
if (!p || *p == '\0')
continue;
tr = trace_array_get_by_name(p, NULL);
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;
trace_boot_init_one_instance(tr, trace_node);
trace_boot_init_instances(trace_node);
disable_tracing_selftest("running boot-time tracing");
return 0;
}
core_initcall_sync(trace_boot_init);
