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- // SPDX-License-Identifier: GPL-2.0
- /*
- * trace_boot.c
- * Tracing kernel boot-time
- */
- #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;
- /* 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, "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 (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);
- }
- }
- #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;
- /* Compose 'handler' parameter */
- 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);
- /* Compose 'action' parameter */
- 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;
- /* All digit started node should be instances. */
- 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;
- }
- /*
- * Histogram boottime tracing syntax.
- *
- * ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] {
- * keys = <KEY>[,...]
- * values = <VAL>[,...]
- * sort = <SORT-KEY>[,...]
- * size = <ENTRIES>
- * name = <HISTNAME>
- * var { <VAR> = <EXPR> ... }
- * pause|continue|clear
- * onmax|onchange[.N] { var = <VAR>; <ACTION> [= <PARAM>] }
- * onmatch[.N] { event = <EVENT>; <ACTION> [= <PARAM>] }
- * filter = <FILTER>
- * }
- *
- * Where <ACTION> are;
- *
- * trace = <EVENT>, <ARG1>[, ...]
- * save = <ARG1>[, ...]
- * snapshot
- */
- 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) {
- /* Expression must not include spaces. */
- append_printf(&buf, end, ":%s=",
- xbc_node_get_data(knode));
- append_str_nospace(&buf, end, p);
- }
- }
- /* Histogram control attributes (mutual exclusive) */
- 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");
- /* Histogram handler and actions */
- 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;
- /* All digit started node should be instances. */
- 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)
- {
- /* do nothing */
- }
- #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 (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
- 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 (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", 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;
- /* per-event key starts with "event.GROUP.EVENT" */
- 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);
- }
- /* 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_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);
- 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);
|