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>
15 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */
17 #include "trace_dynevent.h"
18 #include "trace_kprobe_selftest.h"
19 #include "trace_probe.h"
20 #include "trace_probe_tmpl.h"
22 #define KPROBE_EVENT_SYSTEM "kprobes"
23 #define KRETPROBE_MAXACTIVE_MAX 4096
24 #define MAX_KPROBE_CMDLINE_SIZE 1024
26 /* Kprobe early definition from command line */
27 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
28 static bool kprobe_boot_events_enabled __initdata;
30 static int __init set_kprobe_boot_events(char *str)
32 strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
35 __setup("kprobe_event=", set_kprobe_boot_events);
37 static int trace_kprobe_create(int argc, const char **argv);
38 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
39 static int trace_kprobe_release(struct dyn_event *ev);
40 static bool trace_kprobe_is_busy(struct dyn_event *ev);
41 static bool trace_kprobe_match(const char *system, const char *event,
42 int argc, const char **argv, struct dyn_event *ev);
44 static struct dyn_event_operations trace_kprobe_ops = {
45 .create = trace_kprobe_create,
46 .show = trace_kprobe_show,
47 .is_busy = trace_kprobe_is_busy,
48 .free = trace_kprobe_release,
49 .match = trace_kprobe_match,
53 * Kprobe event core functions
56 struct dyn_event devent;
57 struct kretprobe rp; /* Use rp.kp for kprobe use */
58 unsigned long __percpu *nhit;
59 const char *symbol; /* symbol name */
60 struct trace_probe tp;
63 static bool is_trace_kprobe(struct dyn_event *ev)
65 return ev->ops == &trace_kprobe_ops;
68 static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
70 return container_of(ev, struct trace_kprobe, devent);
74 * for_each_trace_kprobe - iterate over the trace_kprobe list
75 * @pos: the struct trace_kprobe * for each entry
76 * @dpos: the struct dyn_event * to use as a loop cursor
78 #define for_each_trace_kprobe(pos, dpos) \
79 for_each_dyn_event(dpos) \
80 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
82 #define SIZEOF_TRACE_KPROBE(n) \
83 (offsetof(struct trace_kprobe, tp.args) + \
84 (sizeof(struct probe_arg) * (n)))
86 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
88 return tk->rp.handler != NULL;
91 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
93 return tk->symbol ? tk->symbol : "unknown";
96 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
98 return tk->rp.kp.offset;
101 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
103 return !!(kprobe_gone(&tk->rp.kp));
106 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
109 int len = strlen(mod->name);
110 const char *name = trace_kprobe_symbol(tk);
111 return strncmp(mod->name, name, len) == 0 && name[len] == ':';
114 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
121 p = strchr(tk->symbol, ':');
125 mutex_lock(&module_mutex);
126 ret = !!find_module(tk->symbol);
127 mutex_unlock(&module_mutex);
133 static bool trace_kprobe_is_busy(struct dyn_event *ev)
135 struct trace_kprobe *tk = to_trace_kprobe(ev);
137 return trace_probe_is_enabled(&tk->tp);
140 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
141 int argc, const char **argv)
143 char buf[MAX_ARGSTR_LEN + 1];
149 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
150 else if (tk->rp.kp.offset)
151 snprintf(buf, sizeof(buf), "%s+%u",
152 trace_kprobe_symbol(tk), tk->rp.kp.offset);
154 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
155 if (strcmp(buf, argv[0]))
159 return trace_probe_match_command_args(&tk->tp, argc, argv);
162 static bool trace_kprobe_match(const char *system, const char *event,
163 int argc, const char **argv, struct dyn_event *ev)
165 struct trace_kprobe *tk = to_trace_kprobe(ev);
167 return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
168 (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
169 trace_kprobe_match_command_head(tk, argc, argv);
172 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
174 unsigned long nhit = 0;
177 for_each_possible_cpu(cpu)
178 nhit += *per_cpu_ptr(tk->nhit, cpu);
183 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
185 return !(list_empty(&tk->rp.kp.list) &&
186 hlist_unhashed(&tk->rp.kp.hlist));
189 /* Return 0 if it fails to find the symbol address */
190 static nokprobe_inline
191 unsigned long trace_kprobe_address(struct trace_kprobe *tk)
196 addr = (unsigned long)
197 kallsyms_lookup_name(trace_kprobe_symbol(tk));
199 addr += tk->rp.kp.offset;
201 addr = (unsigned long)tk->rp.kp.addr;
206 static nokprobe_inline struct trace_kprobe *
207 trace_kprobe_primary_from_call(struct trace_event_call *call)
209 struct trace_probe *tp;
211 tp = trace_probe_primary_from_call(call);
212 if (WARN_ON_ONCE(!tp))
215 return container_of(tp, struct trace_kprobe, tp);
218 bool trace_kprobe_on_func_entry(struct trace_event_call *call)
220 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
222 return tk ? kprobe_on_func_entry(tk->rp.kp.addr,
223 tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
224 tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false;
227 bool trace_kprobe_error_injectable(struct trace_event_call *call)
229 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
231 return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
235 static int register_kprobe_event(struct trace_kprobe *tk);
236 static int unregister_kprobe_event(struct trace_kprobe *tk);
238 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
239 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
240 struct pt_regs *regs);
242 static void free_trace_kprobe(struct trace_kprobe *tk)
245 trace_probe_cleanup(&tk->tp);
247 free_percpu(tk->nhit);
253 * Allocate new trace_probe and initialize it (including kprobes).
255 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
261 int nargs, bool is_return)
263 struct trace_kprobe *tk;
266 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
270 tk->nhit = alloc_percpu(unsigned long);
275 tk->symbol = kstrdup(symbol, GFP_KERNEL);
278 tk->rp.kp.symbol_name = tk->symbol;
279 tk->rp.kp.offset = offs;
281 tk->rp.kp.addr = addr;
284 tk->rp.handler = kretprobe_dispatcher;
286 tk->rp.kp.pre_handler = kprobe_dispatcher;
288 tk->rp.maxactive = maxactive;
289 INIT_HLIST_NODE(&tk->rp.kp.hlist);
290 INIT_LIST_HEAD(&tk->rp.kp.list);
292 ret = trace_probe_init(&tk->tp, event, group);
296 dyn_event_init(&tk->devent, &trace_kprobe_ops);
299 free_trace_kprobe(tk);
303 static struct trace_kprobe *find_trace_kprobe(const char *event,
306 struct dyn_event *pos;
307 struct trace_kprobe *tk;
309 for_each_trace_kprobe(tk, pos)
310 if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
311 strcmp(trace_probe_group_name(&tk->tp), group) == 0)
316 static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
320 if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
321 if (trace_kprobe_is_return(tk))
322 ret = enable_kretprobe(&tk->rp);
324 ret = enable_kprobe(&tk->rp.kp);
330 static void __disable_trace_kprobe(struct trace_probe *tp)
332 struct trace_probe *pos;
333 struct trace_kprobe *tk;
335 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
336 tk = container_of(pos, struct trace_kprobe, tp);
337 if (!trace_kprobe_is_registered(tk))
339 if (trace_kprobe_is_return(tk))
340 disable_kretprobe(&tk->rp);
342 disable_kprobe(&tk->rp.kp);
348 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
350 static int enable_trace_kprobe(struct trace_event_call *call,
351 struct trace_event_file *file)
353 struct trace_probe *pos, *tp;
354 struct trace_kprobe *tk;
358 tp = trace_probe_primary_from_call(call);
359 if (WARN_ON_ONCE(!tp))
361 enabled = trace_probe_is_enabled(tp);
363 /* This also changes "enabled" state */
365 ret = trace_probe_add_file(tp, file);
369 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
374 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
375 tk = container_of(pos, struct trace_kprobe, tp);
376 if (trace_kprobe_has_gone(tk))
378 ret = __enable_trace_kprobe(tk);
385 /* Failed to enable one of them. Roll back all */
387 __disable_trace_kprobe(tp);
389 trace_probe_remove_file(tp, file);
391 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
398 * Disable trace_probe
399 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
401 static int disable_trace_kprobe(struct trace_event_call *call,
402 struct trace_event_file *file)
404 struct trace_probe *tp;
406 tp = trace_probe_primary_from_call(call);
407 if (WARN_ON_ONCE(!tp))
411 if (!trace_probe_get_file_link(tp, file))
413 if (!trace_probe_has_single_file(tp))
415 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
417 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
419 if (!trace_probe_is_enabled(tp))
420 __disable_trace_kprobe(tp);
425 * Synchronization is done in below function. For perf event,
426 * file == NULL and perf_trace_event_unreg() calls
427 * tracepoint_synchronize_unregister() to ensure synchronize
428 * event. We don't need to care about it.
430 trace_probe_remove_file(tp, file);
435 #if defined(CONFIG_KPROBES_ON_FTRACE) && \
436 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
437 static bool within_notrace_func(struct trace_kprobe *tk)
439 unsigned long offset, size, addr;
441 addr = trace_kprobe_address(tk);
442 if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
445 /* Get the entry address of the target function */
449 * Since ftrace_location_range() does inclusive range check, we need
450 * to subtract 1 byte from the end address.
452 return !ftrace_location_range(addr, addr + size - 1);
455 #define within_notrace_func(tk) (false)
458 /* Internal register function - just handle k*probes and flags */
459 static int __register_trace_kprobe(struct trace_kprobe *tk)
463 if (trace_kprobe_is_registered(tk))
466 if (within_notrace_func(tk)) {
467 pr_warn("Could not probe notrace function %s\n",
468 trace_kprobe_symbol(tk));
472 for (i = 0; i < tk->tp.nr_args; i++) {
473 ret = traceprobe_update_arg(&tk->tp.args[i]);
478 /* Set/clear disabled flag according to tp->flag */
479 if (trace_probe_is_enabled(&tk->tp))
480 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
482 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
484 if (trace_kprobe_is_return(tk))
485 ret = register_kretprobe(&tk->rp);
487 ret = register_kprobe(&tk->rp.kp);
492 /* Internal unregister function - just handle k*probes and flags */
493 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
495 if (trace_kprobe_is_registered(tk)) {
496 if (trace_kprobe_is_return(tk))
497 unregister_kretprobe(&tk->rp);
499 unregister_kprobe(&tk->rp.kp);
500 /* Cleanup kprobe for reuse and mark it unregistered */
501 INIT_HLIST_NODE(&tk->rp.kp.hlist);
502 INIT_LIST_HEAD(&tk->rp.kp.list);
503 if (tk->rp.kp.symbol_name)
504 tk->rp.kp.addr = NULL;
508 /* Unregister a trace_probe and probe_event */
509 static int unregister_trace_kprobe(struct trace_kprobe *tk)
511 /* If other probes are on the event, just unregister kprobe */
512 if (trace_probe_has_sibling(&tk->tp))
515 /* Enabled event can not be unregistered */
516 if (trace_probe_is_enabled(&tk->tp))
519 /* Will fail if probe is being used by ftrace or perf */
520 if (unregister_kprobe_event(tk))
524 __unregister_trace_kprobe(tk);
525 dyn_event_remove(&tk->devent);
526 trace_probe_unlink(&tk->tp);
531 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
532 struct trace_kprobe *comp)
534 struct trace_probe_event *tpe = orig->tp.event;
535 struct trace_probe *pos;
538 list_for_each_entry(pos, &tpe->probes, list) {
539 orig = container_of(pos, struct trace_kprobe, tp);
540 if (strcmp(trace_kprobe_symbol(orig),
541 trace_kprobe_symbol(comp)) ||
542 trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
546 * trace_probe_compare_arg_type() ensured that nr_args and
547 * each argument name and type are same. Let's compare comm.
549 for (i = 0; i < orig->tp.nr_args; i++) {
550 if (strcmp(orig->tp.args[i].comm,
551 comp->tp.args[i].comm))
561 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
565 ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
567 /* Note that argument starts index = 2 */
568 trace_probe_log_set_index(ret + 1);
569 trace_probe_log_err(0, DIFF_ARG_TYPE);
572 if (trace_kprobe_has_same_kprobe(to, tk)) {
573 trace_probe_log_set_index(0);
574 trace_probe_log_err(0, SAME_PROBE);
578 /* Append to existing event */
579 ret = trace_probe_append(&tk->tp, &to->tp);
583 /* Register k*probe */
584 ret = __register_trace_kprobe(tk);
585 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
586 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
591 trace_probe_unlink(&tk->tp);
593 dyn_event_add(&tk->devent);
598 /* Register a trace_probe and probe_event */
599 static int register_trace_kprobe(struct trace_kprobe *tk)
601 struct trace_kprobe *old_tk;
604 mutex_lock(&event_mutex);
606 old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
607 trace_probe_group_name(&tk->tp));
609 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
610 trace_probe_log_set_index(0);
611 trace_probe_log_err(0, DIFF_PROBE_TYPE);
614 ret = append_trace_kprobe(tk, old_tk);
619 /* Register new event */
620 ret = register_kprobe_event(tk);
622 pr_warn("Failed to register probe event(%d)\n", ret);
626 /* Register k*probe */
627 ret = __register_trace_kprobe(tk);
628 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
629 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
634 unregister_kprobe_event(tk);
636 dyn_event_add(&tk->devent);
639 mutex_unlock(&event_mutex);
643 /* Module notifier call back, checking event on the module */
644 static int trace_kprobe_module_callback(struct notifier_block *nb,
645 unsigned long val, void *data)
647 struct module *mod = data;
648 struct dyn_event *pos;
649 struct trace_kprobe *tk;
652 if (val != MODULE_STATE_COMING)
655 /* Update probes on coming module */
656 mutex_lock(&event_mutex);
657 for_each_trace_kprobe(tk, pos) {
658 if (trace_kprobe_within_module(tk, mod)) {
659 /* Don't need to check busy - this should have gone. */
660 __unregister_trace_kprobe(tk);
661 ret = __register_trace_kprobe(tk);
663 pr_warn("Failed to re-register probe %s on %s: %d\n",
664 trace_probe_name(&tk->tp),
668 mutex_unlock(&event_mutex);
673 static struct notifier_block trace_kprobe_module_nb = {
674 .notifier_call = trace_kprobe_module_callback,
675 .priority = 1 /* Invoked after kprobe module callback */
678 /* Convert certain expected symbols into '_' when generating event names */
679 static inline void sanitize_event_name(char *name)
681 while (*name++ != '\0')
682 if (*name == ':' || *name == '.')
686 static int trace_kprobe_create(int argc, const char *argv[])
691 * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
693 * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
695 * $retval : fetch return value
696 * $stack : fetch stack address
697 * $stackN : fetch Nth of stack (N:0-)
698 * $comm : fetch current task comm
699 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
700 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
701 * %REG : fetch register REG
702 * Dereferencing memory fetch:
703 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
704 * Alias name of args:
705 * NAME=FETCHARG : set NAME as alias of FETCHARG.
707 * FETCHARG:TYPE : use TYPE instead of unsigned long.
709 struct trace_kprobe *tk = NULL;
711 bool is_return = false;
712 char *symbol = NULL, *tmp = NULL;
713 const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
717 char buf[MAX_EVENT_NAME_LEN];
718 unsigned int flags = TPARG_FL_KERNEL;
720 switch (argv[0][0]) {
723 flags |= TPARG_FL_RETURN;
733 trace_probe_log_init("trace_kprobe", argc, argv);
735 event = strchr(&argv[0][1], ':');
739 if (isdigit(argv[0][1])) {
741 trace_probe_log_err(1, MAXACT_NO_KPROBE);
745 len = event - &argv[0][1] - 1;
747 len = strlen(&argv[0][1]);
748 if (len > MAX_EVENT_NAME_LEN - 1) {
749 trace_probe_log_err(1, BAD_MAXACT);
752 memcpy(buf, &argv[0][1], len);
754 ret = kstrtouint(buf, 0, &maxactive);
755 if (ret || !maxactive) {
756 trace_probe_log_err(1, BAD_MAXACT);
759 /* kretprobes instances are iterated over via a list. The
760 * maximum should stay reasonable.
762 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
763 trace_probe_log_err(1, MAXACT_TOO_BIG);
768 /* try to parse an address. if that fails, try to read the
769 * input as a symbol. */
770 if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
771 trace_probe_log_set_index(1);
772 /* Check whether uprobe event specified */
773 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
777 /* a symbol specified */
778 symbol = kstrdup(argv[1], GFP_KERNEL);
781 /* TODO: support .init module functions */
782 ret = traceprobe_split_symbol_offset(symbol, &offset);
783 if (ret || offset < 0 || offset > UINT_MAX) {
784 trace_probe_log_err(0, BAD_PROBE_ADDR);
787 if (kprobe_on_func_entry(NULL, symbol, offset))
788 flags |= TPARG_FL_FENTRY;
789 if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
790 trace_probe_log_err(0, BAD_RETPROBE);
795 trace_probe_log_set_index(0);
797 ret = traceprobe_parse_event_name(&event, &group, buf,
802 /* Make a new event name */
804 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
805 is_return ? 'r' : 'p', symbol, offset);
807 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
808 is_return ? 'r' : 'p', addr);
809 sanitize_event_name(buf);
814 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
815 argc - 2, is_return);
818 /* This must return -ENOMEM, else there is a bug */
819 WARN_ON_ONCE(ret != -ENOMEM);
820 goto out; /* We know tk is not allocated */
822 argc -= 2; argv += 2;
824 /* parse arguments */
825 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
826 tmp = kstrdup(argv[i], GFP_KERNEL);
832 trace_probe_log_set_index(i + 2);
833 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
836 goto error; /* This can be -ENOMEM */
839 ret = traceprobe_set_print_fmt(&tk->tp, is_return);
843 ret = register_trace_kprobe(tk);
845 trace_probe_log_set_index(1);
847 trace_probe_log_err(0, BAD_INSN_BNDRY);
848 else if (ret == -ENOENT)
849 trace_probe_log_err(0, BAD_PROBE_ADDR);
850 else if (ret != -ENOMEM && ret != -EEXIST)
851 trace_probe_log_err(0, FAIL_REG_PROBE);
856 trace_probe_log_clear();
863 free_trace_kprobe(tk);
867 static int create_or_delete_trace_kprobe(int argc, char **argv)
871 if (argv[0][0] == '-')
872 return dyn_event_release(argc, argv, &trace_kprobe_ops);
874 ret = trace_kprobe_create(argc, (const char **)argv);
875 return ret == -ECANCELED ? -EINVAL : ret;
878 static int trace_kprobe_release(struct dyn_event *ev)
880 struct trace_kprobe *tk = to_trace_kprobe(ev);
881 int ret = unregister_trace_kprobe(tk);
884 free_trace_kprobe(tk);
888 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
890 struct trace_kprobe *tk = to_trace_kprobe(ev);
893 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
894 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
895 trace_probe_name(&tk->tp));
898 seq_printf(m, " 0x%p", tk->rp.kp.addr);
899 else if (tk->rp.kp.offset)
900 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
903 seq_printf(m, " %s", trace_kprobe_symbol(tk));
905 for (i = 0; i < tk->tp.nr_args; i++)
906 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
912 static int probes_seq_show(struct seq_file *m, void *v)
914 struct dyn_event *ev = v;
916 if (!is_trace_kprobe(ev))
919 return trace_kprobe_show(m, ev);
922 static const struct seq_operations probes_seq_op = {
923 .start = dyn_event_seq_start,
924 .next = dyn_event_seq_next,
925 .stop = dyn_event_seq_stop,
926 .show = probes_seq_show
929 static int probes_open(struct inode *inode, struct file *file)
933 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
934 ret = dyn_events_release_all(&trace_kprobe_ops);
939 return seq_open(file, &probes_seq_op);
942 static ssize_t probes_write(struct file *file, const char __user *buffer,
943 size_t count, loff_t *ppos)
945 return trace_parse_run_command(file, buffer, count, ppos,
946 create_or_delete_trace_kprobe);
949 static const struct file_operations kprobe_events_ops = {
950 .owner = THIS_MODULE,
954 .release = seq_release,
955 .write = probes_write,
958 /* Probes profiling interfaces */
959 static int probes_profile_seq_show(struct seq_file *m, void *v)
961 struct dyn_event *ev = v;
962 struct trace_kprobe *tk;
964 if (!is_trace_kprobe(ev))
967 tk = to_trace_kprobe(ev);
968 seq_printf(m, " %-44s %15lu %15lu\n",
969 trace_probe_name(&tk->tp),
970 trace_kprobe_nhit(tk),
976 static const struct seq_operations profile_seq_op = {
977 .start = dyn_event_seq_start,
978 .next = dyn_event_seq_next,
979 .stop = dyn_event_seq_stop,
980 .show = probes_profile_seq_show
983 static int profile_open(struct inode *inode, struct file *file)
985 return seq_open(file, &profile_seq_op);
988 static const struct file_operations kprobe_profile_ops = {
989 .owner = THIS_MODULE,
990 .open = profile_open,
993 .release = seq_release,
996 /* Kprobe specific fetch functions */
998 /* Return the length of string -- including null terminal byte */
999 static nokprobe_inline int
1000 fetch_store_strlen(unsigned long addr)
1006 ret = probe_kernel_read(&c, (u8 *)addr + len, 1);
1008 } while (c && ret == 0 && len < MAX_STRING_SIZE);
1010 return (ret < 0) ? ret : len;
1013 /* Return the length of string -- including null terminal byte */
1014 static nokprobe_inline int
1015 fetch_store_strlen_user(unsigned long addr)
1017 const void __user *uaddr = (__force const void __user *)addr;
1019 return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE);
1023 * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
1024 * length and relative data location.
1026 static nokprobe_inline int
1027 fetch_store_string(unsigned long addr, void *dest, void *base)
1029 int maxlen = get_loc_len(*(u32 *)dest);
1033 if (unlikely(!maxlen))
1036 __dest = get_loc_data(dest, base);
1039 * Try to get string again, since the string can be changed while
1042 ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen);
1044 *(u32 *)dest = make_data_loc(ret, __dest - base);
1050 * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
1051 * with max length and relative data location.
1053 static nokprobe_inline int
1054 fetch_store_string_user(unsigned long addr, void *dest, void *base)
1056 const void __user *uaddr = (__force const void __user *)addr;
1057 int maxlen = get_loc_len(*(u32 *)dest);
1061 if (unlikely(!maxlen))
1064 __dest = get_loc_data(dest, base);
1066 ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen);
1068 *(u32 *)dest = make_data_loc(ret, __dest - base);
1073 static nokprobe_inline int
1074 probe_mem_read(void *dest, void *src, size_t size)
1076 return probe_kernel_read(dest, src, size);
1079 static nokprobe_inline int
1080 probe_mem_read_user(void *dest, void *src, size_t size)
1082 const void __user *uaddr = (__force const void __user *)src;
1084 return probe_user_read(dest, uaddr, size);
1087 /* Note that we don't verify it, since the code does not come from user space */
1089 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
1095 /* 1st stage: get value from context */
1098 val = regs_get_register(regs, code->param);
1100 case FETCH_OP_STACK:
1101 val = regs_get_kernel_stack_nth(regs, code->param);
1103 case FETCH_OP_STACKP:
1104 val = kernel_stack_pointer(regs);
1106 case FETCH_OP_RETVAL:
1107 val = regs_return_value(regs);
1110 val = code->immediate;
1113 val = (unsigned long)current->comm;
1116 val = (unsigned long)code->data;
1118 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1120 val = regs_get_kernel_argument(regs, code->param);
1123 case FETCH_NOP_SYMBOL: /* Ignore a place holder */
1131 return process_fetch_insn_bottom(code, val, dest, base);
1133 NOKPROBE_SYMBOL(process_fetch_insn)
1135 /* Kprobe handler */
1136 static nokprobe_inline void
1137 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1138 struct trace_event_file *trace_file)
1140 struct kprobe_trace_entry_head *entry;
1141 struct ring_buffer_event *event;
1142 struct ring_buffer *buffer;
1143 int size, dsize, pc;
1144 unsigned long irq_flags;
1145 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1147 WARN_ON(call != trace_file->event_call);
1149 if (trace_trigger_soft_disabled(trace_file))
1152 local_save_flags(irq_flags);
1153 pc = preempt_count();
1155 dsize = __get_data_size(&tk->tp, regs);
1156 size = sizeof(*entry) + tk->tp.size + dsize;
1158 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
1160 size, irq_flags, pc);
1164 entry = ring_buffer_event_data(event);
1165 entry->ip = (unsigned long)tk->rp.kp.addr;
1166 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1168 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1169 entry, irq_flags, pc, regs);
1173 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1175 struct event_file_link *link;
1177 trace_probe_for_each_link_rcu(link, &tk->tp)
1178 __kprobe_trace_func(tk, regs, link->file);
1180 NOKPROBE_SYMBOL(kprobe_trace_func);
1182 /* Kretprobe handler */
1183 static nokprobe_inline void
1184 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1185 struct pt_regs *regs,
1186 struct trace_event_file *trace_file)
1188 struct kretprobe_trace_entry_head *entry;
1189 struct ring_buffer_event *event;
1190 struct ring_buffer *buffer;
1191 int size, pc, dsize;
1192 unsigned long irq_flags;
1193 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1195 WARN_ON(call != trace_file->event_call);
1197 if (trace_trigger_soft_disabled(trace_file))
1200 local_save_flags(irq_flags);
1201 pc = preempt_count();
1203 dsize = __get_data_size(&tk->tp, regs);
1204 size = sizeof(*entry) + tk->tp.size + dsize;
1206 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
1208 size, irq_flags, pc);
1212 entry = ring_buffer_event_data(event);
1213 entry->func = (unsigned long)tk->rp.kp.addr;
1214 entry->ret_ip = (unsigned long)ri->ret_addr;
1215 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1217 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1218 entry, irq_flags, pc, regs);
1222 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1223 struct pt_regs *regs)
1225 struct event_file_link *link;
1227 trace_probe_for_each_link_rcu(link, &tk->tp)
1228 __kretprobe_trace_func(tk, ri, regs, link->file);
1230 NOKPROBE_SYMBOL(kretprobe_trace_func);
1232 /* Event entry printers */
1233 static enum print_line_t
1234 print_kprobe_event(struct trace_iterator *iter, int flags,
1235 struct trace_event *event)
1237 struct kprobe_trace_entry_head *field;
1238 struct trace_seq *s = &iter->seq;
1239 struct trace_probe *tp;
1241 field = (struct kprobe_trace_entry_head *)iter->ent;
1242 tp = trace_probe_primary_from_call(
1243 container_of(event, struct trace_event_call, event));
1244 if (WARN_ON_ONCE(!tp))
1247 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1249 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1252 trace_seq_putc(s, ')');
1254 if (print_probe_args(s, tp->args, tp->nr_args,
1255 (u8 *)&field[1], field) < 0)
1258 trace_seq_putc(s, '\n');
1260 return trace_handle_return(s);
1263 static enum print_line_t
1264 print_kretprobe_event(struct trace_iterator *iter, int flags,
1265 struct trace_event *event)
1267 struct kretprobe_trace_entry_head *field;
1268 struct trace_seq *s = &iter->seq;
1269 struct trace_probe *tp;
1271 field = (struct kretprobe_trace_entry_head *)iter->ent;
1272 tp = trace_probe_primary_from_call(
1273 container_of(event, struct trace_event_call, event));
1274 if (WARN_ON_ONCE(!tp))
1277 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1279 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1282 trace_seq_puts(s, " <- ");
1284 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1287 trace_seq_putc(s, ')');
1289 if (print_probe_args(s, tp->args, tp->nr_args,
1290 (u8 *)&field[1], field) < 0)
1293 trace_seq_putc(s, '\n');
1296 return trace_handle_return(s);
1300 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1303 struct kprobe_trace_entry_head field;
1304 struct trace_probe *tp;
1306 tp = trace_probe_primary_from_call(event_call);
1307 if (WARN_ON_ONCE(!tp))
1310 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1312 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1315 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1318 struct kretprobe_trace_entry_head field;
1319 struct trace_probe *tp;
1321 tp = trace_probe_primary_from_call(event_call);
1322 if (WARN_ON_ONCE(!tp))
1325 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1326 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1328 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1331 #ifdef CONFIG_PERF_EVENTS
1333 /* Kprobe profile handler */
1335 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1337 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1338 struct kprobe_trace_entry_head *entry;
1339 struct hlist_head *head;
1340 int size, __size, dsize;
1343 if (bpf_prog_array_valid(call)) {
1344 unsigned long orig_ip = instruction_pointer(regs);
1347 ret = trace_call_bpf(call, regs);
1350 * We need to check and see if we modified the pc of the
1351 * pt_regs, and if so return 1 so that we don't do the
1354 if (orig_ip != instruction_pointer(regs))
1360 head = this_cpu_ptr(call->perf_events);
1361 if (hlist_empty(head))
1364 dsize = __get_data_size(&tk->tp, regs);
1365 __size = sizeof(*entry) + tk->tp.size + dsize;
1366 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1367 size -= sizeof(u32);
1369 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1373 entry->ip = (unsigned long)tk->rp.kp.addr;
1374 memset(&entry[1], 0, dsize);
1375 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1376 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1380 NOKPROBE_SYMBOL(kprobe_perf_func);
1382 /* Kretprobe profile handler */
1384 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1385 struct pt_regs *regs)
1387 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1388 struct kretprobe_trace_entry_head *entry;
1389 struct hlist_head *head;
1390 int size, __size, dsize;
1393 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1396 head = this_cpu_ptr(call->perf_events);
1397 if (hlist_empty(head))
1400 dsize = __get_data_size(&tk->tp, regs);
1401 __size = sizeof(*entry) + tk->tp.size + dsize;
1402 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1403 size -= sizeof(u32);
1405 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1409 entry->func = (unsigned long)tk->rp.kp.addr;
1410 entry->ret_ip = (unsigned long)ri->ret_addr;
1411 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1412 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1415 NOKPROBE_SYMBOL(kretprobe_perf_func);
1417 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1418 const char **symbol, u64 *probe_offset,
1419 u64 *probe_addr, bool perf_type_tracepoint)
1421 const char *pevent = trace_event_name(event->tp_event);
1422 const char *group = event->tp_event->class->system;
1423 struct trace_kprobe *tk;
1425 if (perf_type_tracepoint)
1426 tk = find_trace_kprobe(pevent, group);
1428 tk = event->tp_event->data;
1432 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1433 : BPF_FD_TYPE_KPROBE;
1435 *symbol = tk->symbol;
1436 *probe_offset = tk->rp.kp.offset;
1441 *probe_addr = (unsigned long)tk->rp.kp.addr;
1445 #endif /* CONFIG_PERF_EVENTS */
1448 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1450 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1451 * lockless, but we can't race with this __init function.
1453 static int kprobe_register(struct trace_event_call *event,
1454 enum trace_reg type, void *data)
1456 struct trace_event_file *file = data;
1459 case TRACE_REG_REGISTER:
1460 return enable_trace_kprobe(event, file);
1461 case TRACE_REG_UNREGISTER:
1462 return disable_trace_kprobe(event, file);
1464 #ifdef CONFIG_PERF_EVENTS
1465 case TRACE_REG_PERF_REGISTER:
1466 return enable_trace_kprobe(event, NULL);
1467 case TRACE_REG_PERF_UNREGISTER:
1468 return disable_trace_kprobe(event, NULL);
1469 case TRACE_REG_PERF_OPEN:
1470 case TRACE_REG_PERF_CLOSE:
1471 case TRACE_REG_PERF_ADD:
1472 case TRACE_REG_PERF_DEL:
1479 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1481 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1484 raw_cpu_inc(*tk->nhit);
1486 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1487 kprobe_trace_func(tk, regs);
1488 #ifdef CONFIG_PERF_EVENTS
1489 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1490 ret = kprobe_perf_func(tk, regs);
1494 NOKPROBE_SYMBOL(kprobe_dispatcher);
1497 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1499 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
1501 raw_cpu_inc(*tk->nhit);
1503 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1504 kretprobe_trace_func(tk, ri, regs);
1505 #ifdef CONFIG_PERF_EVENTS
1506 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1507 kretprobe_perf_func(tk, ri, regs);
1509 return 0; /* We don't tweek kernel, so just return 0 */
1511 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1513 static struct trace_event_functions kretprobe_funcs = {
1514 .trace = print_kretprobe_event
1517 static struct trace_event_functions kprobe_funcs = {
1518 .trace = print_kprobe_event
1521 static inline void init_trace_event_call(struct trace_kprobe *tk)
1523 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1525 if (trace_kprobe_is_return(tk)) {
1526 call->event.funcs = &kretprobe_funcs;
1527 call->class->define_fields = kretprobe_event_define_fields;
1529 call->event.funcs = &kprobe_funcs;
1530 call->class->define_fields = kprobe_event_define_fields;
1533 call->flags = TRACE_EVENT_FL_KPROBE;
1534 call->class->reg = kprobe_register;
1537 static int register_kprobe_event(struct trace_kprobe *tk)
1539 init_trace_event_call(tk);
1541 return trace_probe_register_event_call(&tk->tp);
1544 static int unregister_kprobe_event(struct trace_kprobe *tk)
1546 return trace_probe_unregister_event_call(&tk->tp);
1549 #ifdef CONFIG_PERF_EVENTS
1550 /* create a trace_kprobe, but don't add it to global lists */
1551 struct trace_event_call *
1552 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1555 struct trace_kprobe *tk;
1560 * local trace_kprobes are not added to dyn_event, so they are never
1561 * searched in find_trace_kprobe(). Therefore, there is no concern of
1562 * duplicated name here.
1564 event = func ? func : "DUMMY_EVENT";
1566 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1567 offs, 0 /* maxactive */, 0 /* nargs */,
1571 pr_info("Failed to allocate trace_probe.(%d)\n",
1573 return ERR_CAST(tk);
1576 init_trace_event_call(tk);
1578 if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
1583 ret = __register_trace_kprobe(tk);
1587 return trace_probe_event_call(&tk->tp);
1589 free_trace_kprobe(tk);
1590 return ERR_PTR(ret);
1593 void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1595 struct trace_kprobe *tk;
1597 tk = trace_kprobe_primary_from_call(event_call);
1601 if (trace_probe_is_enabled(&tk->tp)) {
1606 __unregister_trace_kprobe(tk);
1608 free_trace_kprobe(tk);
1610 #endif /* CONFIG_PERF_EVENTS */
1612 static __init void enable_boot_kprobe_events(void)
1614 struct trace_array *tr = top_trace_array();
1615 struct trace_event_file *file;
1616 struct trace_kprobe *tk;
1617 struct dyn_event *pos;
1619 mutex_lock(&event_mutex);
1620 for_each_trace_kprobe(tk, pos) {
1621 list_for_each_entry(file, &tr->events, list)
1622 if (file->event_call == trace_probe_event_call(&tk->tp))
1623 trace_event_enable_disable(file, 1, 0);
1625 mutex_unlock(&event_mutex);
1628 static __init void setup_boot_kprobe_events(void)
1630 char *p, *cmd = kprobe_boot_events_buf;
1633 strreplace(kprobe_boot_events_buf, ',', ' ');
1635 while (cmd && *cmd != '\0') {
1636 p = strchr(cmd, ';');
1640 ret = trace_run_command(cmd, create_or_delete_trace_kprobe);
1642 pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1644 kprobe_boot_events_enabled = true;
1649 enable_boot_kprobe_events();
1652 /* Make a tracefs interface for controlling probe points */
1653 static __init int init_kprobe_trace(void)
1655 struct dentry *d_tracer;
1656 struct dentry *entry;
1659 ret = dyn_event_register(&trace_kprobe_ops);
1663 if (register_module_notifier(&trace_kprobe_module_nb))
1666 d_tracer = tracing_init_dentry();
1667 if (IS_ERR(d_tracer))
1670 entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
1671 NULL, &kprobe_events_ops);
1673 /* Event list interface */
1675 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1677 /* Profile interface */
1678 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
1679 NULL, &kprobe_profile_ops);
1682 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1684 setup_boot_kprobe_events();
1688 fs_initcall(init_kprobe_trace);
1691 #ifdef CONFIG_FTRACE_STARTUP_TEST
1692 static __init struct trace_event_file *
1693 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1695 struct trace_event_file *file;
1697 list_for_each_entry(file, &tr->events, list)
1698 if (file->event_call == trace_probe_event_call(&tk->tp))
1705 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1706 * stage, we can do this lockless.
1708 static __init int kprobe_trace_self_tests_init(void)
1711 int (*target)(int, int, int, int, int, int);
1712 struct trace_kprobe *tk;
1713 struct trace_event_file *file;
1715 if (tracing_is_disabled())
1718 if (kprobe_boot_events_enabled) {
1719 pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n");
1723 target = kprobe_trace_selftest_target;
1725 pr_info("Testing kprobe tracing: ");
1727 ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
1728 create_or_delete_trace_kprobe);
1729 if (WARN_ON_ONCE(ret)) {
1730 pr_warn("error on probing function entry.\n");
1733 /* Enable trace point */
1734 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1735 if (WARN_ON_ONCE(tk == NULL)) {
1736 pr_warn("error on getting new probe.\n");
1739 file = find_trace_probe_file(tk, top_trace_array());
1740 if (WARN_ON_ONCE(file == NULL)) {
1741 pr_warn("error on getting probe file.\n");
1744 enable_trace_kprobe(
1745 trace_probe_event_call(&tk->tp), file);
1749 ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
1750 create_or_delete_trace_kprobe);
1751 if (WARN_ON_ONCE(ret)) {
1752 pr_warn("error on probing function return.\n");
1755 /* Enable trace point */
1756 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1757 if (WARN_ON_ONCE(tk == NULL)) {
1758 pr_warn("error on getting 2nd new probe.\n");
1761 file = find_trace_probe_file(tk, top_trace_array());
1762 if (WARN_ON_ONCE(file == NULL)) {
1763 pr_warn("error on getting probe file.\n");
1766 enable_trace_kprobe(
1767 trace_probe_event_call(&tk->tp), file);
1774 ret = target(1, 2, 3, 4, 5, 6);
1777 * Not expecting an error here, the check is only to prevent the
1778 * optimizer from removing the call to target() as otherwise there
1779 * are no side-effects and the call is never performed.
1784 /* Disable trace points before removing it */
1785 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1786 if (WARN_ON_ONCE(tk == NULL)) {
1787 pr_warn("error on getting test probe.\n");
1790 if (trace_kprobe_nhit(tk) != 1) {
1791 pr_warn("incorrect number of testprobe hits\n");
1795 file = find_trace_probe_file(tk, top_trace_array());
1796 if (WARN_ON_ONCE(file == NULL)) {
1797 pr_warn("error on getting probe file.\n");
1800 disable_trace_kprobe(
1801 trace_probe_event_call(&tk->tp), file);
1804 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1805 if (WARN_ON_ONCE(tk == NULL)) {
1806 pr_warn("error on getting 2nd test probe.\n");
1809 if (trace_kprobe_nhit(tk) != 1) {
1810 pr_warn("incorrect number of testprobe2 hits\n");
1814 file = find_trace_probe_file(tk, top_trace_array());
1815 if (WARN_ON_ONCE(file == NULL)) {
1816 pr_warn("error on getting probe file.\n");
1819 disable_trace_kprobe(
1820 trace_probe_event_call(&tk->tp), file);
1823 ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
1824 if (WARN_ON_ONCE(ret)) {
1825 pr_warn("error on deleting a probe.\n");
1829 ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe);
1830 if (WARN_ON_ONCE(ret)) {
1831 pr_warn("error on deleting a probe.\n");
1836 ret = dyn_events_release_all(&trace_kprobe_ops);
1837 if (WARN_ON_ONCE(ret)) {
1838 pr_warn("error on cleaning up probes.\n");
1842 * Wait for the optimizer work to finish. Otherwise it might fiddle
1843 * with probes in already freed __init text.
1845 wait_for_kprobe_optimizer();
1847 pr_cont("NG: Some tests are failed. Please check them.\n");
1853 late_initcall(kprobe_trace_self_tests_init);