1 // SPDX-License-Identifier: GPL-2.0
3 * Kprobes-based tracing events
5 * Created by Masami Hiramatsu <mhiramat@redhat.com>
8 #define pr_fmt(fmt) "trace_kprobe: " fmt
10 #include <linux/module.h>
11 #include <linux/uaccess.h>
12 #include <linux/rculist.h>
13 #include <linux/error-injection.h>
14 #include <linux/security.h>
16 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */
18 #include "trace_dynevent.h"
19 #include "trace_kprobe_selftest.h"
20 #include "trace_probe.h"
21 #include "trace_probe_tmpl.h"
23 #define KPROBE_EVENT_SYSTEM "kprobes"
24 #define KRETPROBE_MAXACTIVE_MAX 4096
25 #define MAX_KPROBE_CMDLINE_SIZE 1024
27 /* Kprobe early definition from command line */
28 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
29 static bool kprobe_boot_events_enabled __initdata;
31 static int __init set_kprobe_boot_events(char *str)
33 strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
36 __setup("kprobe_event=", set_kprobe_boot_events);
38 static int trace_kprobe_create(int argc, const char **argv);
39 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
40 static int trace_kprobe_release(struct dyn_event *ev);
41 static bool trace_kprobe_is_busy(struct dyn_event *ev);
42 static bool trace_kprobe_match(const char *system, const char *event,
43 int argc, const char **argv, struct dyn_event *ev);
45 static struct dyn_event_operations trace_kprobe_ops = {
46 .create = trace_kprobe_create,
47 .show = trace_kprobe_show,
48 .is_busy = trace_kprobe_is_busy,
49 .free = trace_kprobe_release,
50 .match = trace_kprobe_match,
54 * Kprobe event core functions
57 struct dyn_event devent;
58 struct kretprobe rp; /* Use rp.kp for kprobe use */
59 unsigned long __percpu *nhit;
60 const char *symbol; /* symbol name */
61 struct trace_probe tp;
64 static bool is_trace_kprobe(struct dyn_event *ev)
66 return ev->ops == &trace_kprobe_ops;
69 static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
71 return container_of(ev, struct trace_kprobe, devent);
75 * for_each_trace_kprobe - iterate over the trace_kprobe list
76 * @pos: the struct trace_kprobe * for each entry
77 * @dpos: the struct dyn_event * to use as a loop cursor
79 #define for_each_trace_kprobe(pos, dpos) \
80 for_each_dyn_event(dpos) \
81 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
83 #define SIZEOF_TRACE_KPROBE(n) \
84 (offsetof(struct trace_kprobe, tp.args) + \
85 (sizeof(struct probe_arg) * (n)))
87 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
89 return tk->rp.handler != NULL;
92 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
94 return tk->symbol ? tk->symbol : "unknown";
97 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
99 return tk->rp.kp.offset;
102 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
104 return !!(kprobe_gone(&tk->rp.kp));
107 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
110 int len = strlen(mod->name);
111 const char *name = trace_kprobe_symbol(tk);
112 return strncmp(mod->name, name, len) == 0 && name[len] == ':';
115 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
122 p = strchr(tk->symbol, ':');
126 mutex_lock(&module_mutex);
127 ret = !!find_module(tk->symbol);
128 mutex_unlock(&module_mutex);
134 static bool trace_kprobe_is_busy(struct dyn_event *ev)
136 struct trace_kprobe *tk = to_trace_kprobe(ev);
138 return trace_probe_is_enabled(&tk->tp);
141 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
142 int argc, const char **argv)
144 char buf[MAX_ARGSTR_LEN + 1];
150 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
151 else if (tk->rp.kp.offset)
152 snprintf(buf, sizeof(buf), "%s+%u",
153 trace_kprobe_symbol(tk), tk->rp.kp.offset);
155 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
156 if (strcmp(buf, argv[0]))
160 return trace_probe_match_command_args(&tk->tp, argc, argv);
163 static bool trace_kprobe_match(const char *system, const char *event,
164 int argc, const char **argv, struct dyn_event *ev)
166 struct trace_kprobe *tk = to_trace_kprobe(ev);
168 return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
169 (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
170 trace_kprobe_match_command_head(tk, argc, argv);
173 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
175 unsigned long nhit = 0;
178 for_each_possible_cpu(cpu)
179 nhit += *per_cpu_ptr(tk->nhit, cpu);
184 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
186 return !(list_empty(&tk->rp.kp.list) &&
187 hlist_unhashed(&tk->rp.kp.hlist));
190 /* Return 0 if it fails to find the symbol address */
191 static nokprobe_inline
192 unsigned long trace_kprobe_address(struct trace_kprobe *tk)
197 addr = (unsigned long)
198 kallsyms_lookup_name(trace_kprobe_symbol(tk));
200 addr += tk->rp.kp.offset;
202 addr = (unsigned long)tk->rp.kp.addr;
207 static nokprobe_inline struct trace_kprobe *
208 trace_kprobe_primary_from_call(struct trace_event_call *call)
210 struct trace_probe *tp;
212 tp = trace_probe_primary_from_call(call);
213 if (WARN_ON_ONCE(!tp))
216 return container_of(tp, struct trace_kprobe, tp);
219 bool trace_kprobe_on_func_entry(struct trace_event_call *call)
221 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
223 return tk ? kprobe_on_func_entry(tk->rp.kp.addr,
224 tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
225 tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false;
228 bool trace_kprobe_error_injectable(struct trace_event_call *call)
230 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
232 return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
236 static int register_kprobe_event(struct trace_kprobe *tk);
237 static int unregister_kprobe_event(struct trace_kprobe *tk);
239 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
240 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
241 struct pt_regs *regs);
243 static void free_trace_kprobe(struct trace_kprobe *tk)
246 trace_probe_cleanup(&tk->tp);
248 free_percpu(tk->nhit);
254 * Allocate new trace_probe and initialize it (including kprobes).
256 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
262 int nargs, bool is_return)
264 struct trace_kprobe *tk;
267 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
271 tk->nhit = alloc_percpu(unsigned long);
276 tk->symbol = kstrdup(symbol, GFP_KERNEL);
279 tk->rp.kp.symbol_name = tk->symbol;
280 tk->rp.kp.offset = offs;
282 tk->rp.kp.addr = addr;
285 tk->rp.handler = kretprobe_dispatcher;
287 tk->rp.kp.pre_handler = kprobe_dispatcher;
289 tk->rp.maxactive = maxactive;
290 INIT_HLIST_NODE(&tk->rp.kp.hlist);
291 INIT_LIST_HEAD(&tk->rp.kp.list);
293 ret = trace_probe_init(&tk->tp, event, group);
297 dyn_event_init(&tk->devent, &trace_kprobe_ops);
300 free_trace_kprobe(tk);
304 static struct trace_kprobe *find_trace_kprobe(const char *event,
307 struct dyn_event *pos;
308 struct trace_kprobe *tk;
310 for_each_trace_kprobe(tk, pos)
311 if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
312 strcmp(trace_probe_group_name(&tk->tp), group) == 0)
317 static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
321 if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
322 if (trace_kprobe_is_return(tk))
323 ret = enable_kretprobe(&tk->rp);
325 ret = enable_kprobe(&tk->rp.kp);
331 static void __disable_trace_kprobe(struct trace_probe *tp)
333 struct trace_probe *pos;
334 struct trace_kprobe *tk;
336 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
337 tk = container_of(pos, struct trace_kprobe, tp);
338 if (!trace_kprobe_is_registered(tk))
340 if (trace_kprobe_is_return(tk))
341 disable_kretprobe(&tk->rp);
343 disable_kprobe(&tk->rp.kp);
349 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
351 static int enable_trace_kprobe(struct trace_event_call *call,
352 struct trace_event_file *file)
354 struct trace_probe *pos, *tp;
355 struct trace_kprobe *tk;
359 tp = trace_probe_primary_from_call(call);
360 if (WARN_ON_ONCE(!tp))
362 enabled = trace_probe_is_enabled(tp);
364 /* This also changes "enabled" state */
366 ret = trace_probe_add_file(tp, file);
370 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
375 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
376 tk = container_of(pos, struct trace_kprobe, tp);
377 if (trace_kprobe_has_gone(tk))
379 ret = __enable_trace_kprobe(tk);
386 /* Failed to enable one of them. Roll back all */
388 __disable_trace_kprobe(tp);
390 trace_probe_remove_file(tp, file);
392 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
399 * Disable trace_probe
400 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
402 static int disable_trace_kprobe(struct trace_event_call *call,
403 struct trace_event_file *file)
405 struct trace_probe *tp;
407 tp = trace_probe_primary_from_call(call);
408 if (WARN_ON_ONCE(!tp))
412 if (!trace_probe_get_file_link(tp, file))
414 if (!trace_probe_has_single_file(tp))
416 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
418 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
420 if (!trace_probe_is_enabled(tp))
421 __disable_trace_kprobe(tp);
426 * Synchronization is done in below function. For perf event,
427 * file == NULL and perf_trace_event_unreg() calls
428 * tracepoint_synchronize_unregister() to ensure synchronize
429 * event. We don't need to care about it.
431 trace_probe_remove_file(tp, file);
436 #if defined(CONFIG_KPROBES_ON_FTRACE) && \
437 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
438 static bool within_notrace_func(struct trace_kprobe *tk)
440 unsigned long offset, size, addr;
442 addr = trace_kprobe_address(tk);
443 if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
446 /* Get the entry address of the target function */
450 * Since ftrace_location_range() does inclusive range check, we need
451 * to subtract 1 byte from the end address.
453 return !ftrace_location_range(addr, addr + size - 1);
456 #define within_notrace_func(tk) (false)
459 /* Internal register function - just handle k*probes and flags */
460 static int __register_trace_kprobe(struct trace_kprobe *tk)
464 ret = security_locked_down(LOCKDOWN_KPROBES);
468 if (trace_kprobe_is_registered(tk))
471 if (within_notrace_func(tk)) {
472 pr_warn("Could not probe notrace function %s\n",
473 trace_kprobe_symbol(tk));
477 for (i = 0; i < tk->tp.nr_args; i++) {
478 ret = traceprobe_update_arg(&tk->tp.args[i]);
483 /* Set/clear disabled flag according to tp->flag */
484 if (trace_probe_is_enabled(&tk->tp))
485 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
487 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
489 if (trace_kprobe_is_return(tk))
490 ret = register_kretprobe(&tk->rp);
492 ret = register_kprobe(&tk->rp.kp);
497 /* Internal unregister function - just handle k*probes and flags */
498 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
500 if (trace_kprobe_is_registered(tk)) {
501 if (trace_kprobe_is_return(tk))
502 unregister_kretprobe(&tk->rp);
504 unregister_kprobe(&tk->rp.kp);
505 /* Cleanup kprobe for reuse and mark it unregistered */
506 INIT_HLIST_NODE(&tk->rp.kp.hlist);
507 INIT_LIST_HEAD(&tk->rp.kp.list);
508 if (tk->rp.kp.symbol_name)
509 tk->rp.kp.addr = NULL;
513 /* Unregister a trace_probe and probe_event */
514 static int unregister_trace_kprobe(struct trace_kprobe *tk)
516 /* If other probes are on the event, just unregister kprobe */
517 if (trace_probe_has_sibling(&tk->tp))
520 /* Enabled event can not be unregistered */
521 if (trace_probe_is_enabled(&tk->tp))
524 /* Will fail if probe is being used by ftrace or perf */
525 if (unregister_kprobe_event(tk))
529 __unregister_trace_kprobe(tk);
530 dyn_event_remove(&tk->devent);
531 trace_probe_unlink(&tk->tp);
536 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
537 struct trace_kprobe *comp)
539 struct trace_probe_event *tpe = orig->tp.event;
540 struct trace_probe *pos;
543 list_for_each_entry(pos, &tpe->probes, list) {
544 orig = container_of(pos, struct trace_kprobe, tp);
545 if (strcmp(trace_kprobe_symbol(orig),
546 trace_kprobe_symbol(comp)) ||
547 trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
551 * trace_probe_compare_arg_type() ensured that nr_args and
552 * each argument name and type are same. Let's compare comm.
554 for (i = 0; i < orig->tp.nr_args; i++) {
555 if (strcmp(orig->tp.args[i].comm,
556 comp->tp.args[i].comm))
560 if (i == orig->tp.nr_args)
567 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
571 ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
573 /* Note that argument starts index = 2 */
574 trace_probe_log_set_index(ret + 1);
575 trace_probe_log_err(0, DIFF_ARG_TYPE);
578 if (trace_kprobe_has_same_kprobe(to, tk)) {
579 trace_probe_log_set_index(0);
580 trace_probe_log_err(0, SAME_PROBE);
584 /* Append to existing event */
585 ret = trace_probe_append(&tk->tp, &to->tp);
589 /* Register k*probe */
590 ret = __register_trace_kprobe(tk);
591 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
592 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
597 trace_probe_unlink(&tk->tp);
599 dyn_event_add(&tk->devent);
604 /* Register a trace_probe and probe_event */
605 static int register_trace_kprobe(struct trace_kprobe *tk)
607 struct trace_kprobe *old_tk;
610 mutex_lock(&event_mutex);
612 old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
613 trace_probe_group_name(&tk->tp));
615 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
616 trace_probe_log_set_index(0);
617 trace_probe_log_err(0, DIFF_PROBE_TYPE);
620 ret = append_trace_kprobe(tk, old_tk);
625 /* Register new event */
626 ret = register_kprobe_event(tk);
628 pr_warn("Failed to register probe event(%d)\n", ret);
632 /* Register k*probe */
633 ret = __register_trace_kprobe(tk);
634 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
635 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
640 unregister_kprobe_event(tk);
642 dyn_event_add(&tk->devent);
645 mutex_unlock(&event_mutex);
649 /* Module notifier call back, checking event on the module */
650 static int trace_kprobe_module_callback(struct notifier_block *nb,
651 unsigned long val, void *data)
653 struct module *mod = data;
654 struct dyn_event *pos;
655 struct trace_kprobe *tk;
658 if (val != MODULE_STATE_COMING)
661 /* Update probes on coming module */
662 mutex_lock(&event_mutex);
663 for_each_trace_kprobe(tk, pos) {
664 if (trace_kprobe_within_module(tk, mod)) {
665 /* Don't need to check busy - this should have gone. */
666 __unregister_trace_kprobe(tk);
667 ret = __register_trace_kprobe(tk);
669 pr_warn("Failed to re-register probe %s on %s: %d\n",
670 trace_probe_name(&tk->tp),
674 mutex_unlock(&event_mutex);
679 static struct notifier_block trace_kprobe_module_nb = {
680 .notifier_call = trace_kprobe_module_callback,
681 .priority = 1 /* Invoked after kprobe module callback */
684 /* Convert certain expected symbols into '_' when generating event names */
685 static inline void sanitize_event_name(char *name)
687 while (*name++ != '\0')
688 if (*name == ':' || *name == '.')
692 static int trace_kprobe_create(int argc, const char *argv[])
697 * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
699 * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
701 * $retval : fetch return value
702 * $stack : fetch stack address
703 * $stackN : fetch Nth of stack (N:0-)
704 * $comm : fetch current task comm
705 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
706 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
707 * %REG : fetch register REG
708 * Dereferencing memory fetch:
709 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
710 * Alias name of args:
711 * NAME=FETCHARG : set NAME as alias of FETCHARG.
713 * FETCHARG:TYPE : use TYPE instead of unsigned long.
715 struct trace_kprobe *tk = NULL;
717 bool is_return = false;
718 char *symbol = NULL, *tmp = NULL;
719 const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
723 char buf[MAX_EVENT_NAME_LEN];
724 unsigned int flags = TPARG_FL_KERNEL;
726 switch (argv[0][0]) {
729 flags |= TPARG_FL_RETURN;
739 trace_probe_log_init("trace_kprobe", argc, argv);
741 event = strchr(&argv[0][1], ':');
745 if (isdigit(argv[0][1])) {
747 trace_probe_log_err(1, MAXACT_NO_KPROBE);
751 len = event - &argv[0][1] - 1;
753 len = strlen(&argv[0][1]);
754 if (len > MAX_EVENT_NAME_LEN - 1) {
755 trace_probe_log_err(1, BAD_MAXACT);
758 memcpy(buf, &argv[0][1], len);
760 ret = kstrtouint(buf, 0, &maxactive);
761 if (ret || !maxactive) {
762 trace_probe_log_err(1, BAD_MAXACT);
765 /* kretprobes instances are iterated over via a list. The
766 * maximum should stay reasonable.
768 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
769 trace_probe_log_err(1, MAXACT_TOO_BIG);
774 /* try to parse an address. if that fails, try to read the
775 * input as a symbol. */
776 if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
777 trace_probe_log_set_index(1);
778 /* Check whether uprobe event specified */
779 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
783 /* a symbol specified */
784 symbol = kstrdup(argv[1], GFP_KERNEL);
787 /* TODO: support .init module functions */
788 ret = traceprobe_split_symbol_offset(symbol, &offset);
789 if (ret || offset < 0 || offset > UINT_MAX) {
790 trace_probe_log_err(0, BAD_PROBE_ADDR);
793 if (kprobe_on_func_entry(NULL, symbol, offset))
794 flags |= TPARG_FL_FENTRY;
795 if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
796 trace_probe_log_err(0, BAD_RETPROBE);
801 trace_probe_log_set_index(0);
803 ret = traceprobe_parse_event_name(&event, &group, buf,
808 /* Make a new event name */
810 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
811 is_return ? 'r' : 'p', symbol, offset);
813 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
814 is_return ? 'r' : 'p', addr);
815 sanitize_event_name(buf);
820 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
821 argc - 2, is_return);
824 /* This must return -ENOMEM, else there is a bug */
825 WARN_ON_ONCE(ret != -ENOMEM);
826 goto out; /* We know tk is not allocated */
828 argc -= 2; argv += 2;
830 /* parse arguments */
831 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
832 tmp = kstrdup(argv[i], GFP_KERNEL);
838 trace_probe_log_set_index(i + 2);
839 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
842 goto error; /* This can be -ENOMEM */
845 ret = traceprobe_set_print_fmt(&tk->tp, is_return);
849 ret = register_trace_kprobe(tk);
851 trace_probe_log_set_index(1);
853 trace_probe_log_err(0, BAD_INSN_BNDRY);
854 else if (ret == -ENOENT)
855 trace_probe_log_err(0, BAD_PROBE_ADDR);
856 else if (ret != -ENOMEM && ret != -EEXIST)
857 trace_probe_log_err(0, FAIL_REG_PROBE);
862 trace_probe_log_clear();
869 free_trace_kprobe(tk);
873 static int create_or_delete_trace_kprobe(int argc, char **argv)
877 if (argv[0][0] == '-')
878 return dyn_event_release(argc, argv, &trace_kprobe_ops);
880 ret = trace_kprobe_create(argc, (const char **)argv);
881 return ret == -ECANCELED ? -EINVAL : ret;
884 static int trace_kprobe_release(struct dyn_event *ev)
886 struct trace_kprobe *tk = to_trace_kprobe(ev);
887 int ret = unregister_trace_kprobe(tk);
890 free_trace_kprobe(tk);
894 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
896 struct trace_kprobe *tk = to_trace_kprobe(ev);
899 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
900 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
901 trace_probe_name(&tk->tp));
904 seq_printf(m, " 0x%p", tk->rp.kp.addr);
905 else if (tk->rp.kp.offset)
906 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
909 seq_printf(m, " %s", trace_kprobe_symbol(tk));
911 for (i = 0; i < tk->tp.nr_args; i++)
912 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
918 static int probes_seq_show(struct seq_file *m, void *v)
920 struct dyn_event *ev = v;
922 if (!is_trace_kprobe(ev))
925 return trace_kprobe_show(m, ev);
928 static const struct seq_operations probes_seq_op = {
929 .start = dyn_event_seq_start,
930 .next = dyn_event_seq_next,
931 .stop = dyn_event_seq_stop,
932 .show = probes_seq_show
935 static int probes_open(struct inode *inode, struct file *file)
939 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
940 ret = dyn_events_release_all(&trace_kprobe_ops);
945 return seq_open(file, &probes_seq_op);
948 static ssize_t probes_write(struct file *file, const char __user *buffer,
949 size_t count, loff_t *ppos)
951 return trace_parse_run_command(file, buffer, count, ppos,
952 create_or_delete_trace_kprobe);
955 static const struct file_operations kprobe_events_ops = {
956 .owner = THIS_MODULE,
960 .release = seq_release,
961 .write = probes_write,
964 /* Probes profiling interfaces */
965 static int probes_profile_seq_show(struct seq_file *m, void *v)
967 struct dyn_event *ev = v;
968 struct trace_kprobe *tk;
970 if (!is_trace_kprobe(ev))
973 tk = to_trace_kprobe(ev);
974 seq_printf(m, " %-44s %15lu %15lu\n",
975 trace_probe_name(&tk->tp),
976 trace_kprobe_nhit(tk),
982 static const struct seq_operations profile_seq_op = {
983 .start = dyn_event_seq_start,
984 .next = dyn_event_seq_next,
985 .stop = dyn_event_seq_stop,
986 .show = probes_profile_seq_show
989 static int profile_open(struct inode *inode, struct file *file)
991 return seq_open(file, &profile_seq_op);
994 static const struct file_operations kprobe_profile_ops = {
995 .owner = THIS_MODULE,
996 .open = profile_open,
999 .release = seq_release,
1002 /* Kprobe specific fetch functions */
1004 /* Return the length of string -- including null terminal byte */
1005 static nokprobe_inline int
1006 fetch_store_strlen(unsigned long addr)
1012 ret = probe_kernel_read(&c, (u8 *)addr + len, 1);
1014 } while (c && ret == 0 && len < MAX_STRING_SIZE);
1016 return (ret < 0) ? ret : len;
1019 /* Return the length of string -- including null terminal byte */
1020 static nokprobe_inline int
1021 fetch_store_strlen_user(unsigned long addr)
1023 const void __user *uaddr = (__force const void __user *)addr;
1025 return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE);
1029 * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
1030 * length and relative data location.
1032 static nokprobe_inline int
1033 fetch_store_string(unsigned long addr, void *dest, void *base)
1035 int maxlen = get_loc_len(*(u32 *)dest);
1039 if (unlikely(!maxlen))
1042 __dest = get_loc_data(dest, base);
1045 * Try to get string again, since the string can be changed while
1048 ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen);
1050 *(u32 *)dest = make_data_loc(ret, __dest - base);
1056 * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
1057 * with max length and relative data location.
1059 static nokprobe_inline int
1060 fetch_store_string_user(unsigned long addr, void *dest, void *base)
1062 const void __user *uaddr = (__force const void __user *)addr;
1063 int maxlen = get_loc_len(*(u32 *)dest);
1067 if (unlikely(!maxlen))
1070 __dest = get_loc_data(dest, base);
1072 ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen);
1074 *(u32 *)dest = make_data_loc(ret, __dest - base);
1079 static nokprobe_inline int
1080 probe_mem_read(void *dest, void *src, size_t size)
1082 return probe_kernel_read(dest, src, size);
1085 static nokprobe_inline int
1086 probe_mem_read_user(void *dest, void *src, size_t size)
1088 const void __user *uaddr = (__force const void __user *)src;
1090 return probe_user_read(dest, uaddr, size);
1093 /* Note that we don't verify it, since the code does not come from user space */
1095 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
1101 /* 1st stage: get value from context */
1104 val = regs_get_register(regs, code->param);
1106 case FETCH_OP_STACK:
1107 val = regs_get_kernel_stack_nth(regs, code->param);
1109 case FETCH_OP_STACKP:
1110 val = kernel_stack_pointer(regs);
1112 case FETCH_OP_RETVAL:
1113 val = regs_return_value(regs);
1116 val = code->immediate;
1119 val = (unsigned long)current->comm;
1122 val = (unsigned long)code->data;
1124 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1126 val = regs_get_kernel_argument(regs, code->param);
1129 case FETCH_NOP_SYMBOL: /* Ignore a place holder */
1137 return process_fetch_insn_bottom(code, val, dest, base);
1139 NOKPROBE_SYMBOL(process_fetch_insn)
1141 /* Kprobe handler */
1142 static nokprobe_inline void
1143 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1144 struct trace_event_file *trace_file)
1146 struct kprobe_trace_entry_head *entry;
1147 struct ring_buffer_event *event;
1148 struct ring_buffer *buffer;
1149 int size, dsize, pc;
1150 unsigned long irq_flags;
1151 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1153 WARN_ON(call != trace_file->event_call);
1155 if (trace_trigger_soft_disabled(trace_file))
1158 local_save_flags(irq_flags);
1159 pc = preempt_count();
1161 dsize = __get_data_size(&tk->tp, regs);
1162 size = sizeof(*entry) + tk->tp.size + dsize;
1164 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
1166 size, irq_flags, pc);
1170 entry = ring_buffer_event_data(event);
1171 entry->ip = (unsigned long)tk->rp.kp.addr;
1172 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1174 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1175 entry, irq_flags, pc, regs);
1179 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1181 struct event_file_link *link;
1183 trace_probe_for_each_link_rcu(link, &tk->tp)
1184 __kprobe_trace_func(tk, regs, link->file);
1186 NOKPROBE_SYMBOL(kprobe_trace_func);
1188 /* Kretprobe handler */
1189 static nokprobe_inline void
1190 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1191 struct pt_regs *regs,
1192 struct trace_event_file *trace_file)
1194 struct kretprobe_trace_entry_head *entry;
1195 struct ring_buffer_event *event;
1196 struct ring_buffer *buffer;
1197 int size, pc, dsize;
1198 unsigned long irq_flags;
1199 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1201 WARN_ON(call != trace_file->event_call);
1203 if (trace_trigger_soft_disabled(trace_file))
1206 local_save_flags(irq_flags);
1207 pc = preempt_count();
1209 dsize = __get_data_size(&tk->tp, regs);
1210 size = sizeof(*entry) + tk->tp.size + dsize;
1212 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
1214 size, irq_flags, pc);
1218 entry = ring_buffer_event_data(event);
1219 entry->func = (unsigned long)tk->rp.kp.addr;
1220 entry->ret_ip = (unsigned long)ri->ret_addr;
1221 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1223 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1224 entry, irq_flags, pc, regs);
1228 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1229 struct pt_regs *regs)
1231 struct event_file_link *link;
1233 trace_probe_for_each_link_rcu(link, &tk->tp)
1234 __kretprobe_trace_func(tk, ri, regs, link->file);
1236 NOKPROBE_SYMBOL(kretprobe_trace_func);
1238 /* Event entry printers */
1239 static enum print_line_t
1240 print_kprobe_event(struct trace_iterator *iter, int flags,
1241 struct trace_event *event)
1243 struct kprobe_trace_entry_head *field;
1244 struct trace_seq *s = &iter->seq;
1245 struct trace_probe *tp;
1247 field = (struct kprobe_trace_entry_head *)iter->ent;
1248 tp = trace_probe_primary_from_call(
1249 container_of(event, struct trace_event_call, event));
1250 if (WARN_ON_ONCE(!tp))
1253 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1255 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1258 trace_seq_putc(s, ')');
1260 if (print_probe_args(s, tp->args, tp->nr_args,
1261 (u8 *)&field[1], field) < 0)
1264 trace_seq_putc(s, '\n');
1266 return trace_handle_return(s);
1269 static enum print_line_t
1270 print_kretprobe_event(struct trace_iterator *iter, int flags,
1271 struct trace_event *event)
1273 struct kretprobe_trace_entry_head *field;
1274 struct trace_seq *s = &iter->seq;
1275 struct trace_probe *tp;
1277 field = (struct kretprobe_trace_entry_head *)iter->ent;
1278 tp = trace_probe_primary_from_call(
1279 container_of(event, struct trace_event_call, event));
1280 if (WARN_ON_ONCE(!tp))
1283 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1285 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1288 trace_seq_puts(s, " <- ");
1290 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1293 trace_seq_putc(s, ')');
1295 if (print_probe_args(s, tp->args, tp->nr_args,
1296 (u8 *)&field[1], field) < 0)
1299 trace_seq_putc(s, '\n');
1302 return trace_handle_return(s);
1306 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1309 struct kprobe_trace_entry_head field;
1310 struct trace_probe *tp;
1312 tp = trace_probe_primary_from_call(event_call);
1313 if (WARN_ON_ONCE(!tp))
1316 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1318 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1321 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1324 struct kretprobe_trace_entry_head field;
1325 struct trace_probe *tp;
1327 tp = trace_probe_primary_from_call(event_call);
1328 if (WARN_ON_ONCE(!tp))
1331 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1332 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1334 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1337 #ifdef CONFIG_PERF_EVENTS
1339 /* Kprobe profile handler */
1341 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1343 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1344 struct kprobe_trace_entry_head *entry;
1345 struct hlist_head *head;
1346 int size, __size, dsize;
1349 if (bpf_prog_array_valid(call)) {
1350 unsigned long orig_ip = instruction_pointer(regs);
1353 ret = trace_call_bpf(call, regs);
1356 * We need to check and see if we modified the pc of the
1357 * pt_regs, and if so return 1 so that we don't do the
1360 if (orig_ip != instruction_pointer(regs))
1366 head = this_cpu_ptr(call->perf_events);
1367 if (hlist_empty(head))
1370 dsize = __get_data_size(&tk->tp, regs);
1371 __size = sizeof(*entry) + tk->tp.size + dsize;
1372 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1373 size -= sizeof(u32);
1375 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1379 entry->ip = (unsigned long)tk->rp.kp.addr;
1380 memset(&entry[1], 0, dsize);
1381 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1382 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1386 NOKPROBE_SYMBOL(kprobe_perf_func);
1388 /* Kretprobe profile handler */
1390 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1391 struct pt_regs *regs)
1393 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1394 struct kretprobe_trace_entry_head *entry;
1395 struct hlist_head *head;
1396 int size, __size, dsize;
1399 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1402 head = this_cpu_ptr(call->perf_events);
1403 if (hlist_empty(head))
1406 dsize = __get_data_size(&tk->tp, regs);
1407 __size = sizeof(*entry) + tk->tp.size + dsize;
1408 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1409 size -= sizeof(u32);
1411 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1415 entry->func = (unsigned long)tk->rp.kp.addr;
1416 entry->ret_ip = (unsigned long)ri->ret_addr;
1417 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1418 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1421 NOKPROBE_SYMBOL(kretprobe_perf_func);
1423 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1424 const char **symbol, u64 *probe_offset,
1425 u64 *probe_addr, bool perf_type_tracepoint)
1427 const char *pevent = trace_event_name(event->tp_event);
1428 const char *group = event->tp_event->class->system;
1429 struct trace_kprobe *tk;
1431 if (perf_type_tracepoint)
1432 tk = find_trace_kprobe(pevent, group);
1434 tk = event->tp_event->data;
1438 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1439 : BPF_FD_TYPE_KPROBE;
1441 *symbol = tk->symbol;
1442 *probe_offset = tk->rp.kp.offset;
1447 *probe_addr = (unsigned long)tk->rp.kp.addr;
1451 #endif /* CONFIG_PERF_EVENTS */
1454 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1456 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1457 * lockless, but we can't race with this __init function.
1459 static int kprobe_register(struct trace_event_call *event,
1460 enum trace_reg type, void *data)
1462 struct trace_event_file *file = data;
1465 case TRACE_REG_REGISTER:
1466 return enable_trace_kprobe(event, file);
1467 case TRACE_REG_UNREGISTER:
1468 return disable_trace_kprobe(event, file);
1470 #ifdef CONFIG_PERF_EVENTS
1471 case TRACE_REG_PERF_REGISTER:
1472 return enable_trace_kprobe(event, NULL);
1473 case TRACE_REG_PERF_UNREGISTER:
1474 return disable_trace_kprobe(event, NULL);
1475 case TRACE_REG_PERF_OPEN:
1476 case TRACE_REG_PERF_CLOSE:
1477 case TRACE_REG_PERF_ADD:
1478 case TRACE_REG_PERF_DEL:
1485 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1487 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1490 raw_cpu_inc(*tk->nhit);
1492 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1493 kprobe_trace_func(tk, regs);
1494 #ifdef CONFIG_PERF_EVENTS
1495 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1496 ret = kprobe_perf_func(tk, regs);
1500 NOKPROBE_SYMBOL(kprobe_dispatcher);
1503 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1505 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
1507 raw_cpu_inc(*tk->nhit);
1509 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1510 kretprobe_trace_func(tk, ri, regs);
1511 #ifdef CONFIG_PERF_EVENTS
1512 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1513 kretprobe_perf_func(tk, ri, regs);
1515 return 0; /* We don't tweek kernel, so just return 0 */
1517 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1519 static struct trace_event_functions kretprobe_funcs = {
1520 .trace = print_kretprobe_event
1523 static struct trace_event_functions kprobe_funcs = {
1524 .trace = print_kprobe_event
1527 static inline void init_trace_event_call(struct trace_kprobe *tk)
1529 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1531 if (trace_kprobe_is_return(tk)) {
1532 call->event.funcs = &kretprobe_funcs;
1533 call->class->define_fields = kretprobe_event_define_fields;
1535 call->event.funcs = &kprobe_funcs;
1536 call->class->define_fields = kprobe_event_define_fields;
1539 call->flags = TRACE_EVENT_FL_KPROBE;
1540 call->class->reg = kprobe_register;
1543 static int register_kprobe_event(struct trace_kprobe *tk)
1545 init_trace_event_call(tk);
1547 return trace_probe_register_event_call(&tk->tp);
1550 static int unregister_kprobe_event(struct trace_kprobe *tk)
1552 return trace_probe_unregister_event_call(&tk->tp);
1555 #ifdef CONFIG_PERF_EVENTS
1556 /* create a trace_kprobe, but don't add it to global lists */
1557 struct trace_event_call *
1558 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1561 struct trace_kprobe *tk;
1566 * local trace_kprobes are not added to dyn_event, so they are never
1567 * searched in find_trace_kprobe(). Therefore, there is no concern of
1568 * duplicated name here.
1570 event = func ? func : "DUMMY_EVENT";
1572 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1573 offs, 0 /* maxactive */, 0 /* nargs */,
1577 pr_info("Failed to allocate trace_probe.(%d)\n",
1579 return ERR_CAST(tk);
1582 init_trace_event_call(tk);
1584 if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
1589 ret = __register_trace_kprobe(tk);
1593 return trace_probe_event_call(&tk->tp);
1595 free_trace_kprobe(tk);
1596 return ERR_PTR(ret);
1599 void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1601 struct trace_kprobe *tk;
1603 tk = trace_kprobe_primary_from_call(event_call);
1607 if (trace_probe_is_enabled(&tk->tp)) {
1612 __unregister_trace_kprobe(tk);
1614 free_trace_kprobe(tk);
1616 #endif /* CONFIG_PERF_EVENTS */
1618 static __init void enable_boot_kprobe_events(void)
1620 struct trace_array *tr = top_trace_array();
1621 struct trace_event_file *file;
1622 struct trace_kprobe *tk;
1623 struct dyn_event *pos;
1625 mutex_lock(&event_mutex);
1626 for_each_trace_kprobe(tk, pos) {
1627 list_for_each_entry(file, &tr->events, list)
1628 if (file->event_call == trace_probe_event_call(&tk->tp))
1629 trace_event_enable_disable(file, 1, 0);
1631 mutex_unlock(&event_mutex);
1634 static __init void setup_boot_kprobe_events(void)
1636 char *p, *cmd = kprobe_boot_events_buf;
1639 strreplace(kprobe_boot_events_buf, ',', ' ');
1641 while (cmd && *cmd != '\0') {
1642 p = strchr(cmd, ';');
1646 ret = trace_run_command(cmd, create_or_delete_trace_kprobe);
1648 pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1650 kprobe_boot_events_enabled = true;
1655 enable_boot_kprobe_events();
1658 /* Make a tracefs interface for controlling probe points */
1659 static __init int init_kprobe_trace(void)
1661 struct dentry *d_tracer;
1662 struct dentry *entry;
1665 ret = dyn_event_register(&trace_kprobe_ops);
1669 if (register_module_notifier(&trace_kprobe_module_nb))
1672 d_tracer = tracing_init_dentry();
1673 if (IS_ERR(d_tracer))
1676 entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
1677 NULL, &kprobe_events_ops);
1679 /* Event list interface */
1681 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1683 /* Profile interface */
1684 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
1685 NULL, &kprobe_profile_ops);
1688 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1690 setup_boot_kprobe_events();
1694 fs_initcall(init_kprobe_trace);
1697 #ifdef CONFIG_FTRACE_STARTUP_TEST
1698 static __init struct trace_event_file *
1699 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1701 struct trace_event_file *file;
1703 list_for_each_entry(file, &tr->events, list)
1704 if (file->event_call == trace_probe_event_call(&tk->tp))
1711 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1712 * stage, we can do this lockless.
1714 static __init int kprobe_trace_self_tests_init(void)
1717 int (*target)(int, int, int, int, int, int);
1718 struct trace_kprobe *tk;
1719 struct trace_event_file *file;
1721 if (tracing_is_disabled())
1724 if (kprobe_boot_events_enabled) {
1725 pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n");
1729 target = kprobe_trace_selftest_target;
1731 pr_info("Testing kprobe tracing: ");
1733 ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
1734 create_or_delete_trace_kprobe);
1735 if (WARN_ON_ONCE(ret)) {
1736 pr_warn("error on probing function entry.\n");
1739 /* Enable trace point */
1740 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1741 if (WARN_ON_ONCE(tk == NULL)) {
1742 pr_warn("error on getting new probe.\n");
1745 file = find_trace_probe_file(tk, top_trace_array());
1746 if (WARN_ON_ONCE(file == NULL)) {
1747 pr_warn("error on getting probe file.\n");
1750 enable_trace_kprobe(
1751 trace_probe_event_call(&tk->tp), file);
1755 ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
1756 create_or_delete_trace_kprobe);
1757 if (WARN_ON_ONCE(ret)) {
1758 pr_warn("error on probing function return.\n");
1761 /* Enable trace point */
1762 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1763 if (WARN_ON_ONCE(tk == NULL)) {
1764 pr_warn("error on getting 2nd new probe.\n");
1767 file = find_trace_probe_file(tk, top_trace_array());
1768 if (WARN_ON_ONCE(file == NULL)) {
1769 pr_warn("error on getting probe file.\n");
1772 enable_trace_kprobe(
1773 trace_probe_event_call(&tk->tp), file);
1780 ret = target(1, 2, 3, 4, 5, 6);
1783 * Not expecting an error here, the check is only to prevent the
1784 * optimizer from removing the call to target() as otherwise there
1785 * are no side-effects and the call is never performed.
1790 /* Disable trace points before removing it */
1791 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1792 if (WARN_ON_ONCE(tk == NULL)) {
1793 pr_warn("error on getting test probe.\n");
1796 if (trace_kprobe_nhit(tk) != 1) {
1797 pr_warn("incorrect number of testprobe hits\n");
1801 file = find_trace_probe_file(tk, top_trace_array());
1802 if (WARN_ON_ONCE(file == NULL)) {
1803 pr_warn("error on getting probe file.\n");
1806 disable_trace_kprobe(
1807 trace_probe_event_call(&tk->tp), file);
1810 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1811 if (WARN_ON_ONCE(tk == NULL)) {
1812 pr_warn("error on getting 2nd test probe.\n");
1815 if (trace_kprobe_nhit(tk) != 1) {
1816 pr_warn("incorrect number of testprobe2 hits\n");
1820 file = find_trace_probe_file(tk, top_trace_array());
1821 if (WARN_ON_ONCE(file == NULL)) {
1822 pr_warn("error on getting probe file.\n");
1825 disable_trace_kprobe(
1826 trace_probe_event_call(&tk->tp), file);
1829 ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
1830 if (WARN_ON_ONCE(ret)) {
1831 pr_warn("error on deleting a probe.\n");
1835 ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe);
1836 if (WARN_ON_ONCE(ret)) {
1837 pr_warn("error on deleting a probe.\n");
1842 ret = dyn_events_release_all(&trace_kprobe_ops);
1843 if (WARN_ON_ONCE(ret)) {
1844 pr_warn("error on cleaning up probes.\n");
1848 * Wait for the optimizer work to finish. Otherwise it might fiddle
1849 * with probes in already freed __init text.
1851 wait_for_kprobe_optimizer();
1853 pr_cont("NG: Some tests are failed. Please check them.\n");
1859 late_initcall(kprobe_trace_self_tests_init);