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/security.h>
11 #include <linux/module.h>
12 #include <linux/uaccess.h>
13 #include <linux/rculist.h>
14 #include <linux/error-injection.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
26 /* Kprobe early definition from command line */
27 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
29 static int __init set_kprobe_boot_events(char *str)
31 strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
32 disable_tracing_selftest("running kprobe events");
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(module_name(mod));
111 const char *name = trace_kprobe_symbol(tk);
113 return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
116 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
123 p = strchr(tk->symbol, ':');
127 mutex_lock(&module_mutex);
128 ret = !!find_module(tk->symbol);
129 mutex_unlock(&module_mutex);
135 static bool trace_kprobe_is_busy(struct dyn_event *ev)
137 struct trace_kprobe *tk = to_trace_kprobe(ev);
139 return trace_probe_is_enabled(&tk->tp);
142 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
143 int argc, const char **argv)
145 char buf[MAX_ARGSTR_LEN + 1];
151 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
152 else if (tk->rp.kp.offset)
153 snprintf(buf, sizeof(buf), "%s+%u",
154 trace_kprobe_symbol(tk), tk->rp.kp.offset);
156 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
157 if (strcmp(buf, argv[0]))
161 return trace_probe_match_command_args(&tk->tp, argc, argv);
164 static bool trace_kprobe_match(const char *system, const char *event,
165 int argc, const char **argv, struct dyn_event *ev)
167 struct trace_kprobe *tk = to_trace_kprobe(ev);
169 return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
170 (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
171 trace_kprobe_match_command_head(tk, argc, argv);
174 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
176 unsigned long nhit = 0;
179 for_each_possible_cpu(cpu)
180 nhit += *per_cpu_ptr(tk->nhit, cpu);
185 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
187 return !(list_empty(&tk->rp.kp.list) &&
188 hlist_unhashed(&tk->rp.kp.hlist));
191 /* Return 0 if it fails to find the symbol address */
192 static nokprobe_inline
193 unsigned long trace_kprobe_address(struct trace_kprobe *tk)
198 addr = (unsigned long)
199 kallsyms_lookup_name(trace_kprobe_symbol(tk));
201 addr += tk->rp.kp.offset;
203 addr = (unsigned long)tk->rp.kp.addr;
208 static nokprobe_inline struct trace_kprobe *
209 trace_kprobe_primary_from_call(struct trace_event_call *call)
211 struct trace_probe *tp;
213 tp = trace_probe_primary_from_call(call);
214 if (WARN_ON_ONCE(!tp))
217 return container_of(tp, struct trace_kprobe, tp);
220 bool trace_kprobe_on_func_entry(struct trace_event_call *call)
222 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
224 return tk ? (kprobe_on_func_entry(tk->rp.kp.addr,
225 tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
226 tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
229 bool trace_kprobe_error_injectable(struct trace_event_call *call)
231 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
233 return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
237 static int register_kprobe_event(struct trace_kprobe *tk);
238 static int unregister_kprobe_event(struct trace_kprobe *tk);
240 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
241 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
242 struct pt_regs *regs);
244 static void free_trace_kprobe(struct trace_kprobe *tk)
247 trace_probe_cleanup(&tk->tp);
249 free_percpu(tk->nhit);
255 * Allocate new trace_probe and initialize it (including kprobes).
257 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
263 int nargs, bool is_return)
265 struct trace_kprobe *tk;
268 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
272 tk->nhit = alloc_percpu(unsigned long);
277 tk->symbol = kstrdup(symbol, GFP_KERNEL);
280 tk->rp.kp.symbol_name = tk->symbol;
281 tk->rp.kp.offset = offs;
283 tk->rp.kp.addr = addr;
286 tk->rp.handler = kretprobe_dispatcher;
288 tk->rp.kp.pre_handler = kprobe_dispatcher;
290 tk->rp.maxactive = maxactive;
291 INIT_HLIST_NODE(&tk->rp.kp.hlist);
292 INIT_LIST_HEAD(&tk->rp.kp.list);
294 ret = trace_probe_init(&tk->tp, event, group, false);
298 dyn_event_init(&tk->devent, &trace_kprobe_ops);
301 free_trace_kprobe(tk);
305 static struct trace_kprobe *find_trace_kprobe(const char *event,
308 struct dyn_event *pos;
309 struct trace_kprobe *tk;
311 for_each_trace_kprobe(tk, pos)
312 if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
313 strcmp(trace_probe_group_name(&tk->tp), group) == 0)
318 static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
322 if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
323 if (trace_kprobe_is_return(tk))
324 ret = enable_kretprobe(&tk->rp);
326 ret = enable_kprobe(&tk->rp.kp);
332 static void __disable_trace_kprobe(struct trace_probe *tp)
334 struct trace_probe *pos;
335 struct trace_kprobe *tk;
337 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
338 tk = container_of(pos, struct trace_kprobe, tp);
339 if (!trace_kprobe_is_registered(tk))
341 if (trace_kprobe_is_return(tk))
342 disable_kretprobe(&tk->rp);
344 disable_kprobe(&tk->rp.kp);
350 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
352 static int enable_trace_kprobe(struct trace_event_call *call,
353 struct trace_event_file *file)
355 struct trace_probe *pos, *tp;
356 struct trace_kprobe *tk;
360 tp = trace_probe_primary_from_call(call);
361 if (WARN_ON_ONCE(!tp))
363 enabled = trace_probe_is_enabled(tp);
365 /* This also changes "enabled" state */
367 ret = trace_probe_add_file(tp, file);
371 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
376 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
377 tk = container_of(pos, struct trace_kprobe, tp);
378 if (trace_kprobe_has_gone(tk))
380 ret = __enable_trace_kprobe(tk);
387 /* Failed to enable one of them. Roll back all */
389 __disable_trace_kprobe(tp);
391 trace_probe_remove_file(tp, file);
393 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
400 * Disable trace_probe
401 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
403 static int disable_trace_kprobe(struct trace_event_call *call,
404 struct trace_event_file *file)
406 struct trace_probe *tp;
408 tp = trace_probe_primary_from_call(call);
409 if (WARN_ON_ONCE(!tp))
413 if (!trace_probe_get_file_link(tp, file))
415 if (!trace_probe_has_single_file(tp))
417 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
419 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
421 if (!trace_probe_is_enabled(tp))
422 __disable_trace_kprobe(tp);
427 * Synchronization is done in below function. For perf event,
428 * file == NULL and perf_trace_event_unreg() calls
429 * tracepoint_synchronize_unregister() to ensure synchronize
430 * event. We don't need to care about it.
432 trace_probe_remove_file(tp, file);
437 #if defined(CONFIG_DYNAMIC_FTRACE) && \
438 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
439 static bool __within_notrace_func(unsigned long addr)
441 unsigned long offset, size;
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 static bool within_notrace_func(struct trace_kprobe *tk)
458 unsigned long addr = trace_kprobe_address(tk);
459 char symname[KSYM_NAME_LEN], *p;
461 if (!__within_notrace_func(addr))
464 /* Check if the address is on a suffixed-symbol */
465 if (!lookup_symbol_name(addr, symname)) {
466 p = strchr(symname, '.');
470 addr = (unsigned long)kprobe_lookup_name(symname, 0);
472 return __within_notrace_func(addr);
478 #define within_notrace_func(tk) (false)
481 /* Internal register function - just handle k*probes and flags */
482 static int __register_trace_kprobe(struct trace_kprobe *tk)
486 ret = security_locked_down(LOCKDOWN_KPROBES);
490 if (trace_kprobe_is_registered(tk))
493 if (within_notrace_func(tk)) {
494 pr_warn("Could not probe notrace function %s\n",
495 trace_kprobe_symbol(tk));
499 for (i = 0; i < tk->tp.nr_args; i++) {
500 ret = traceprobe_update_arg(&tk->tp.args[i]);
505 /* Set/clear disabled flag according to tp->flag */
506 if (trace_probe_is_enabled(&tk->tp))
507 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
509 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
511 if (trace_kprobe_is_return(tk))
512 ret = register_kretprobe(&tk->rp);
514 ret = register_kprobe(&tk->rp.kp);
519 /* Internal unregister function - just handle k*probes and flags */
520 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
522 if (trace_kprobe_is_registered(tk)) {
523 if (trace_kprobe_is_return(tk))
524 unregister_kretprobe(&tk->rp);
526 unregister_kprobe(&tk->rp.kp);
527 /* Cleanup kprobe for reuse and mark it unregistered */
528 INIT_HLIST_NODE(&tk->rp.kp.hlist);
529 INIT_LIST_HEAD(&tk->rp.kp.list);
530 if (tk->rp.kp.symbol_name)
531 tk->rp.kp.addr = NULL;
535 /* Unregister a trace_probe and probe_event */
536 static int unregister_trace_kprobe(struct trace_kprobe *tk)
538 /* If other probes are on the event, just unregister kprobe */
539 if (trace_probe_has_sibling(&tk->tp))
542 /* Enabled event can not be unregistered */
543 if (trace_probe_is_enabled(&tk->tp))
546 /* Will fail if probe is being used by ftrace or perf */
547 if (unregister_kprobe_event(tk))
551 __unregister_trace_kprobe(tk);
552 dyn_event_remove(&tk->devent);
553 trace_probe_unlink(&tk->tp);
558 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
559 struct trace_kprobe *comp)
561 struct trace_probe_event *tpe = orig->tp.event;
562 struct trace_probe *pos;
565 list_for_each_entry(pos, &tpe->probes, list) {
566 orig = container_of(pos, struct trace_kprobe, tp);
567 if (strcmp(trace_kprobe_symbol(orig),
568 trace_kprobe_symbol(comp)) ||
569 trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
573 * trace_probe_compare_arg_type() ensured that nr_args and
574 * each argument name and type are same. Let's compare comm.
576 for (i = 0; i < orig->tp.nr_args; i++) {
577 if (strcmp(orig->tp.args[i].comm,
578 comp->tp.args[i].comm))
582 if (i == orig->tp.nr_args)
589 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
593 ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
595 /* Note that argument starts index = 2 */
596 trace_probe_log_set_index(ret + 1);
597 trace_probe_log_err(0, DIFF_ARG_TYPE);
600 if (trace_kprobe_has_same_kprobe(to, tk)) {
601 trace_probe_log_set_index(0);
602 trace_probe_log_err(0, SAME_PROBE);
606 /* Append to existing event */
607 ret = trace_probe_append(&tk->tp, &to->tp);
611 /* Register k*probe */
612 ret = __register_trace_kprobe(tk);
613 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
614 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
619 trace_probe_unlink(&tk->tp);
621 dyn_event_add(&tk->devent);
626 /* Register a trace_probe and probe_event */
627 static int register_trace_kprobe(struct trace_kprobe *tk)
629 struct trace_kprobe *old_tk;
632 mutex_lock(&event_mutex);
634 old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
635 trace_probe_group_name(&tk->tp));
637 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
638 trace_probe_log_set_index(0);
639 trace_probe_log_err(0, DIFF_PROBE_TYPE);
642 ret = append_trace_kprobe(tk, old_tk);
647 /* Register new event */
648 ret = register_kprobe_event(tk);
650 if (ret == -EEXIST) {
651 trace_probe_log_set_index(0);
652 trace_probe_log_err(0, EVENT_EXIST);
654 pr_warn("Failed to register probe event(%d)\n", ret);
658 /* Register k*probe */
659 ret = __register_trace_kprobe(tk);
660 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
661 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
666 unregister_kprobe_event(tk);
668 dyn_event_add(&tk->devent);
671 mutex_unlock(&event_mutex);
675 /* Module notifier call back, checking event on the module */
676 static int trace_kprobe_module_callback(struct notifier_block *nb,
677 unsigned long val, void *data)
679 struct module *mod = data;
680 struct dyn_event *pos;
681 struct trace_kprobe *tk;
684 if (val != MODULE_STATE_COMING)
687 /* Update probes on coming module */
688 mutex_lock(&event_mutex);
689 for_each_trace_kprobe(tk, pos) {
690 if (trace_kprobe_within_module(tk, mod)) {
691 /* Don't need to check busy - this should have gone. */
692 __unregister_trace_kprobe(tk);
693 ret = __register_trace_kprobe(tk);
695 pr_warn("Failed to re-register probe %s on %s: %d\n",
696 trace_probe_name(&tk->tp),
697 module_name(mod), ret);
700 mutex_unlock(&event_mutex);
705 static struct notifier_block trace_kprobe_module_nb = {
706 .notifier_call = trace_kprobe_module_callback,
707 .priority = 1 /* Invoked after kprobe module callback */
710 /* Convert certain expected symbols into '_' when generating event names */
711 static inline void sanitize_event_name(char *name)
713 while (*name++ != '\0')
714 if (*name == ':' || *name == '.')
718 static int trace_kprobe_create(int argc, const char *argv[])
723 * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
725 * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
727 * p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
730 * $retval : fetch return value
731 * $stack : fetch stack address
732 * $stackN : fetch Nth of stack (N:0-)
733 * $comm : fetch current task comm
734 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
735 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
736 * %REG : fetch register REG
737 * Dereferencing memory fetch:
738 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
739 * Alias name of args:
740 * NAME=FETCHARG : set NAME as alias of FETCHARG.
742 * FETCHARG:TYPE : use TYPE instead of unsigned long.
744 struct trace_kprobe *tk = NULL;
746 bool is_return = false;
747 char *symbol = NULL, *tmp = NULL;
748 const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
752 char buf[MAX_EVENT_NAME_LEN];
753 unsigned int flags = TPARG_FL_KERNEL;
755 switch (argv[0][0]) {
767 trace_probe_log_init("trace_kprobe", argc, argv);
769 event = strchr(&argv[0][1], ':');
773 if (isdigit(argv[0][1])) {
775 trace_probe_log_err(1, MAXACT_NO_KPROBE);
779 len = event - &argv[0][1] - 1;
781 len = strlen(&argv[0][1]);
782 if (len > MAX_EVENT_NAME_LEN - 1) {
783 trace_probe_log_err(1, BAD_MAXACT);
786 memcpy(buf, &argv[0][1], len);
788 ret = kstrtouint(buf, 0, &maxactive);
789 if (ret || !maxactive) {
790 trace_probe_log_err(1, BAD_MAXACT);
793 /* kretprobes instances are iterated over via a list. The
794 * maximum should stay reasonable.
796 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
797 trace_probe_log_err(1, MAXACT_TOO_BIG);
802 /* try to parse an address. if that fails, try to read the
803 * input as a symbol. */
804 if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
805 trace_probe_log_set_index(1);
806 /* Check whether uprobe event specified */
807 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
811 /* a symbol specified */
812 symbol = kstrdup(argv[1], GFP_KERNEL);
816 tmp = strchr(symbol, '%');
818 if (!strcmp(tmp, "%return")) {
822 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
827 /* TODO: support .init module functions */
828 ret = traceprobe_split_symbol_offset(symbol, &offset);
829 if (ret || offset < 0 || offset > UINT_MAX) {
830 trace_probe_log_err(0, BAD_PROBE_ADDR);
834 flags |= TPARG_FL_RETURN;
835 ret = kprobe_on_func_entry(NULL, symbol, offset);
837 flags |= TPARG_FL_FENTRY;
838 /* Defer the ENOENT case until register kprobe */
839 if (ret == -EINVAL && is_return) {
840 trace_probe_log_err(0, BAD_RETPROBE);
845 trace_probe_log_set_index(0);
847 ret = traceprobe_parse_event_name(&event, &group, buf,
852 /* Make a new event name */
854 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
855 is_return ? 'r' : 'p', symbol, offset);
857 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
858 is_return ? 'r' : 'p', addr);
859 sanitize_event_name(buf);
864 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
865 argc - 2, is_return);
868 /* This must return -ENOMEM, else there is a bug */
869 WARN_ON_ONCE(ret != -ENOMEM);
870 goto out; /* We know tk is not allocated */
872 argc -= 2; argv += 2;
874 /* parse arguments */
875 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
876 tmp = kstrdup(argv[i], GFP_KERNEL);
882 trace_probe_log_set_index(i + 2);
883 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
886 goto error; /* This can be -ENOMEM */
889 ret = traceprobe_set_print_fmt(&tk->tp, is_return);
893 ret = register_trace_kprobe(tk);
895 trace_probe_log_set_index(1);
897 trace_probe_log_err(0, BAD_INSN_BNDRY);
898 else if (ret == -ENOENT)
899 trace_probe_log_err(0, BAD_PROBE_ADDR);
900 else if (ret != -ENOMEM && ret != -EEXIST)
901 trace_probe_log_err(0, FAIL_REG_PROBE);
906 trace_probe_log_clear();
913 free_trace_kprobe(tk);
917 static int create_or_delete_trace_kprobe(int argc, char **argv)
921 if (argv[0][0] == '-')
922 return dyn_event_release(argc, argv, &trace_kprobe_ops);
924 ret = trace_kprobe_create(argc, (const char **)argv);
925 return ret == -ECANCELED ? -EINVAL : ret;
928 static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
930 return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe);
934 * kprobe_event_cmd_init - Initialize a kprobe event command object
935 * @cmd: A pointer to the dynevent_cmd struct representing the new event
936 * @buf: A pointer to the buffer used to build the command
937 * @maxlen: The length of the buffer passed in @buf
939 * Initialize a synthetic event command object. Use this before
940 * calling any of the other kprobe_event functions.
942 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
944 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
945 trace_kprobe_run_command);
947 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
950 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
951 * @cmd: A pointer to the dynevent_cmd struct representing the new event
952 * @kretprobe: Is this a return probe?
953 * @name: The name of the kprobe event
954 * @loc: The location of the kprobe event
955 * @...: Variable number of arg (pairs), one pair for each field
957 * NOTE: Users normally won't want to call this function directly, but
958 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
959 * adds a NULL to the end of the arg list. If this function is used
960 * directly, make sure the last arg in the variable arg list is NULL.
962 * Generate a kprobe event command to be executed by
963 * kprobe_event_gen_cmd_end(). This function can be used to generate the
964 * complete command or only the first part of it; in the latter case,
965 * kprobe_event_add_fields() can be used to add more fields following this.
967 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
968 * returns -EINVAL if @loc == NULL.
970 * Return: 0 if successful, error otherwise.
972 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
973 const char *name, const char *loc, ...)
975 char buf[MAX_EVENT_NAME_LEN];
976 struct dynevent_arg arg;
980 if (cmd->type != DYNEVENT_TYPE_KPROBE)
987 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
989 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
991 ret = dynevent_str_add(cmd, buf);
995 dynevent_arg_init(&arg, 0);
997 ret = dynevent_arg_add(cmd, &arg, NULL);
1001 va_start(args, loc);
1005 field = va_arg(args, const char *);
1009 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1015 ret = dynevent_arg_add(cmd, &arg, NULL);
1023 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1026 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1027 * @cmd: A pointer to the dynevent_cmd struct representing the new event
1028 * @...: Variable number of arg (pairs), one pair for each field
1030 * NOTE: Users normally won't want to call this function directly, but
1031 * rather use the kprobe_event_add_fields() wrapper, which
1032 * automatically adds a NULL to the end of the arg list. If this
1033 * function is used directly, make sure the last arg in the variable
1036 * Add probe fields to an existing kprobe command using a variable
1037 * list of args. Fields are added in the same order they're listed.
1039 * Return: 0 if successful, error otherwise.
1041 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1043 struct dynevent_arg arg;
1047 if (cmd->type != DYNEVENT_TYPE_KPROBE)
1050 dynevent_arg_init(&arg, 0);
1052 va_start(args, cmd);
1056 field = va_arg(args, const char *);
1060 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1066 ret = dynevent_arg_add(cmd, &arg, NULL);
1074 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1077 * kprobe_event_delete - Delete a kprobe event
1078 * @name: The name of the kprobe event to delete
1080 * Delete a kprobe event with the give @name from kernel code rather
1081 * than directly from the command line.
1083 * Return: 0 if successful, error otherwise.
1085 int kprobe_event_delete(const char *name)
1087 char buf[MAX_EVENT_NAME_LEN];
1089 snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1091 return trace_run_command(buf, create_or_delete_trace_kprobe);
1093 EXPORT_SYMBOL_GPL(kprobe_event_delete);
1095 static int trace_kprobe_release(struct dyn_event *ev)
1097 struct trace_kprobe *tk = to_trace_kprobe(ev);
1098 int ret = unregister_trace_kprobe(tk);
1101 free_trace_kprobe(tk);
1105 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1107 struct trace_kprobe *tk = to_trace_kprobe(ev);
1110 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1111 if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1112 seq_printf(m, "%d", tk->rp.maxactive);
1113 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1114 trace_probe_name(&tk->tp));
1117 seq_printf(m, " 0x%p", tk->rp.kp.addr);
1118 else if (tk->rp.kp.offset)
1119 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1122 seq_printf(m, " %s", trace_kprobe_symbol(tk));
1124 for (i = 0; i < tk->tp.nr_args; i++)
1125 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1131 static int probes_seq_show(struct seq_file *m, void *v)
1133 struct dyn_event *ev = v;
1135 if (!is_trace_kprobe(ev))
1138 return trace_kprobe_show(m, ev);
1141 static const struct seq_operations probes_seq_op = {
1142 .start = dyn_event_seq_start,
1143 .next = dyn_event_seq_next,
1144 .stop = dyn_event_seq_stop,
1145 .show = probes_seq_show
1148 static int probes_open(struct inode *inode, struct file *file)
1152 ret = security_locked_down(LOCKDOWN_TRACEFS);
1156 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1157 ret = dyn_events_release_all(&trace_kprobe_ops);
1162 return seq_open(file, &probes_seq_op);
1165 static ssize_t probes_write(struct file *file, const char __user *buffer,
1166 size_t count, loff_t *ppos)
1168 return trace_parse_run_command(file, buffer, count, ppos,
1169 create_or_delete_trace_kprobe);
1172 static const struct file_operations kprobe_events_ops = {
1173 .owner = THIS_MODULE,
1174 .open = probes_open,
1176 .llseek = seq_lseek,
1177 .release = seq_release,
1178 .write = probes_write,
1181 /* Probes profiling interfaces */
1182 static int probes_profile_seq_show(struct seq_file *m, void *v)
1184 struct dyn_event *ev = v;
1185 struct trace_kprobe *tk;
1186 unsigned long nmissed;
1188 if (!is_trace_kprobe(ev))
1191 tk = to_trace_kprobe(ev);
1192 nmissed = trace_kprobe_is_return(tk) ?
1193 tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
1194 seq_printf(m, " %-44s %15lu %15lu\n",
1195 trace_probe_name(&tk->tp),
1196 trace_kprobe_nhit(tk),
1202 static const struct seq_operations profile_seq_op = {
1203 .start = dyn_event_seq_start,
1204 .next = dyn_event_seq_next,
1205 .stop = dyn_event_seq_stop,
1206 .show = probes_profile_seq_show
1209 static int profile_open(struct inode *inode, struct file *file)
1213 ret = security_locked_down(LOCKDOWN_TRACEFS);
1217 return seq_open(file, &profile_seq_op);
1220 static const struct file_operations kprobe_profile_ops = {
1221 .owner = THIS_MODULE,
1222 .open = profile_open,
1224 .llseek = seq_lseek,
1225 .release = seq_release,
1228 /* Kprobe specific fetch functions */
1230 /* Return the length of string -- including null terminal byte */
1231 static nokprobe_inline int
1232 fetch_store_strlen_user(unsigned long addr)
1234 const void __user *uaddr = (__force const void __user *)addr;
1236 return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
1239 /* Return the length of string -- including null terminal byte */
1240 static nokprobe_inline int
1241 fetch_store_strlen(unsigned long addr)
1246 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1247 if (addr < TASK_SIZE)
1248 return fetch_store_strlen_user(addr);
1252 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
1254 } while (c && ret == 0 && len < MAX_STRING_SIZE);
1256 return (ret < 0) ? ret : len;
1260 * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
1261 * with max length and relative data location.
1263 static nokprobe_inline int
1264 fetch_store_string_user(unsigned long addr, void *dest, void *base)
1266 const void __user *uaddr = (__force const void __user *)addr;
1267 int maxlen = get_loc_len(*(u32 *)dest);
1271 if (unlikely(!maxlen))
1274 __dest = get_loc_data(dest, base);
1276 ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
1278 *(u32 *)dest = make_data_loc(ret, __dest - base);
1284 * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
1285 * length and relative data location.
1287 static nokprobe_inline int
1288 fetch_store_string(unsigned long addr, void *dest, void *base)
1290 int maxlen = get_loc_len(*(u32 *)dest);
1294 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1295 if ((unsigned long)addr < TASK_SIZE)
1296 return fetch_store_string_user(addr, dest, base);
1299 if (unlikely(!maxlen))
1302 __dest = get_loc_data(dest, base);
1305 * Try to get string again, since the string can be changed while
1308 ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
1310 *(u32 *)dest = make_data_loc(ret, __dest - base);
1315 static nokprobe_inline int
1316 probe_mem_read_user(void *dest, void *src, size_t size)
1318 const void __user *uaddr = (__force const void __user *)src;
1320 return copy_from_user_nofault(dest, uaddr, size);
1323 static nokprobe_inline int
1324 probe_mem_read(void *dest, void *src, size_t size)
1326 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1327 if ((unsigned long)src < TASK_SIZE)
1328 return probe_mem_read_user(dest, src, size);
1330 return copy_from_kernel_nofault(dest, src, size);
1333 /* Note that we don't verify it, since the code does not come from user space */
1335 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
1338 struct pt_regs *regs = rec;
1342 /* 1st stage: get value from context */
1345 val = regs_get_register(regs, code->param);
1347 case FETCH_OP_STACK:
1348 val = regs_get_kernel_stack_nth(regs, code->param);
1350 case FETCH_OP_STACKP:
1351 val = kernel_stack_pointer(regs);
1353 case FETCH_OP_RETVAL:
1354 val = regs_return_value(regs);
1357 val = code->immediate;
1360 val = (unsigned long)current->comm;
1363 val = (unsigned long)code->data;
1365 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1367 val = regs_get_kernel_argument(regs, code->param);
1370 case FETCH_NOP_SYMBOL: /* Ignore a place holder */
1378 return process_fetch_insn_bottom(code, val, dest, base);
1380 NOKPROBE_SYMBOL(process_fetch_insn)
1382 /* Kprobe handler */
1383 static nokprobe_inline void
1384 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1385 struct trace_event_file *trace_file)
1387 struct kprobe_trace_entry_head *entry;
1388 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1389 struct trace_event_buffer fbuffer;
1392 WARN_ON(call != trace_file->event_call);
1394 if (trace_trigger_soft_disabled(trace_file))
1397 local_save_flags(fbuffer.flags);
1398 fbuffer.pc = preempt_count();
1399 fbuffer.trace_file = trace_file;
1401 dsize = __get_data_size(&tk->tp, regs);
1404 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1406 sizeof(*entry) + tk->tp.size + dsize,
1407 fbuffer.flags, fbuffer.pc);
1411 fbuffer.regs = regs;
1412 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1413 entry->ip = (unsigned long)tk->rp.kp.addr;
1414 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1416 trace_event_buffer_commit(&fbuffer);
1420 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1422 struct event_file_link *link;
1424 trace_probe_for_each_link_rcu(link, &tk->tp)
1425 __kprobe_trace_func(tk, regs, link->file);
1427 NOKPROBE_SYMBOL(kprobe_trace_func);
1429 /* Kretprobe handler */
1430 static nokprobe_inline void
1431 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1432 struct pt_regs *regs,
1433 struct trace_event_file *trace_file)
1435 struct kretprobe_trace_entry_head *entry;
1436 struct trace_event_buffer fbuffer;
1437 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1440 WARN_ON(call != trace_file->event_call);
1442 if (trace_trigger_soft_disabled(trace_file))
1445 local_save_flags(fbuffer.flags);
1446 fbuffer.pc = preempt_count();
1447 fbuffer.trace_file = trace_file;
1449 dsize = __get_data_size(&tk->tp, regs);
1451 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1453 sizeof(*entry) + tk->tp.size + dsize,
1454 fbuffer.flags, fbuffer.pc);
1458 fbuffer.regs = regs;
1459 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1460 entry->func = (unsigned long)tk->rp.kp.addr;
1461 entry->ret_ip = (unsigned long)ri->ret_addr;
1462 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1464 trace_event_buffer_commit(&fbuffer);
1468 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1469 struct pt_regs *regs)
1471 struct event_file_link *link;
1473 trace_probe_for_each_link_rcu(link, &tk->tp)
1474 __kretprobe_trace_func(tk, ri, regs, link->file);
1476 NOKPROBE_SYMBOL(kretprobe_trace_func);
1478 /* Event entry printers */
1479 static enum print_line_t
1480 print_kprobe_event(struct trace_iterator *iter, int flags,
1481 struct trace_event *event)
1483 struct kprobe_trace_entry_head *field;
1484 struct trace_seq *s = &iter->seq;
1485 struct trace_probe *tp;
1487 field = (struct kprobe_trace_entry_head *)iter->ent;
1488 tp = trace_probe_primary_from_call(
1489 container_of(event, struct trace_event_call, event));
1490 if (WARN_ON_ONCE(!tp))
1493 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1495 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1498 trace_seq_putc(s, ')');
1500 if (print_probe_args(s, tp->args, tp->nr_args,
1501 (u8 *)&field[1], field) < 0)
1504 trace_seq_putc(s, '\n');
1506 return trace_handle_return(s);
1509 static enum print_line_t
1510 print_kretprobe_event(struct trace_iterator *iter, int flags,
1511 struct trace_event *event)
1513 struct kretprobe_trace_entry_head *field;
1514 struct trace_seq *s = &iter->seq;
1515 struct trace_probe *tp;
1517 field = (struct kretprobe_trace_entry_head *)iter->ent;
1518 tp = trace_probe_primary_from_call(
1519 container_of(event, struct trace_event_call, event));
1520 if (WARN_ON_ONCE(!tp))
1523 trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1525 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1528 trace_seq_puts(s, " <- ");
1530 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1533 trace_seq_putc(s, ')');
1535 if (print_probe_args(s, tp->args, tp->nr_args,
1536 (u8 *)&field[1], field) < 0)
1539 trace_seq_putc(s, '\n');
1542 return trace_handle_return(s);
1546 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1549 struct kprobe_trace_entry_head field;
1550 struct trace_probe *tp;
1552 tp = trace_probe_primary_from_call(event_call);
1553 if (WARN_ON_ONCE(!tp))
1556 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1558 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1561 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1564 struct kretprobe_trace_entry_head field;
1565 struct trace_probe *tp;
1567 tp = trace_probe_primary_from_call(event_call);
1568 if (WARN_ON_ONCE(!tp))
1571 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1572 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1574 return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1577 #ifdef CONFIG_PERF_EVENTS
1579 /* Kprobe profile handler */
1581 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1583 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1584 struct kprobe_trace_entry_head *entry;
1585 struct hlist_head *head;
1586 int size, __size, dsize;
1589 if (bpf_prog_array_valid(call)) {
1590 unsigned long orig_ip = instruction_pointer(regs);
1593 ret = trace_call_bpf(call, regs);
1596 * We need to check and see if we modified the pc of the
1597 * pt_regs, and if so return 1 so that we don't do the
1600 if (orig_ip != instruction_pointer(regs))
1606 head = this_cpu_ptr(call->perf_events);
1607 if (hlist_empty(head))
1610 dsize = __get_data_size(&tk->tp, regs);
1611 __size = sizeof(*entry) + tk->tp.size + dsize;
1612 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1613 size -= sizeof(u32);
1615 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1619 entry->ip = (unsigned long)tk->rp.kp.addr;
1620 memset(&entry[1], 0, dsize);
1621 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1622 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1626 NOKPROBE_SYMBOL(kprobe_perf_func);
1628 /* Kretprobe profile handler */
1630 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1631 struct pt_regs *regs)
1633 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1634 struct kretprobe_trace_entry_head *entry;
1635 struct hlist_head *head;
1636 int size, __size, dsize;
1639 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1642 head = this_cpu_ptr(call->perf_events);
1643 if (hlist_empty(head))
1646 dsize = __get_data_size(&tk->tp, regs);
1647 __size = sizeof(*entry) + tk->tp.size + dsize;
1648 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1649 size -= sizeof(u32);
1651 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1655 entry->func = (unsigned long)tk->rp.kp.addr;
1656 entry->ret_ip = (unsigned long)ri->ret_addr;
1657 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1658 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1661 NOKPROBE_SYMBOL(kretprobe_perf_func);
1663 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1664 const char **symbol, u64 *probe_offset,
1665 u64 *probe_addr, bool perf_type_tracepoint)
1667 const char *pevent = trace_event_name(event->tp_event);
1668 const char *group = event->tp_event->class->system;
1669 struct trace_kprobe *tk;
1671 if (perf_type_tracepoint)
1672 tk = find_trace_kprobe(pevent, group);
1674 tk = trace_kprobe_primary_from_call(event->tp_event);
1678 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1679 : BPF_FD_TYPE_KPROBE;
1681 *symbol = tk->symbol;
1682 *probe_offset = tk->rp.kp.offset;
1687 *probe_addr = (unsigned long)tk->rp.kp.addr;
1691 #endif /* CONFIG_PERF_EVENTS */
1694 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1696 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1697 * lockless, but we can't race with this __init function.
1699 static int kprobe_register(struct trace_event_call *event,
1700 enum trace_reg type, void *data)
1702 struct trace_event_file *file = data;
1705 case TRACE_REG_REGISTER:
1706 return enable_trace_kprobe(event, file);
1707 case TRACE_REG_UNREGISTER:
1708 return disable_trace_kprobe(event, file);
1710 #ifdef CONFIG_PERF_EVENTS
1711 case TRACE_REG_PERF_REGISTER:
1712 return enable_trace_kprobe(event, NULL);
1713 case TRACE_REG_PERF_UNREGISTER:
1714 return disable_trace_kprobe(event, NULL);
1715 case TRACE_REG_PERF_OPEN:
1716 case TRACE_REG_PERF_CLOSE:
1717 case TRACE_REG_PERF_ADD:
1718 case TRACE_REG_PERF_DEL:
1725 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1727 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1730 raw_cpu_inc(*tk->nhit);
1732 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1733 kprobe_trace_func(tk, regs);
1734 #ifdef CONFIG_PERF_EVENTS
1735 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1736 ret = kprobe_perf_func(tk, regs);
1740 NOKPROBE_SYMBOL(kprobe_dispatcher);
1743 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1745 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
1747 raw_cpu_inc(*tk->nhit);
1749 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1750 kretprobe_trace_func(tk, ri, regs);
1751 #ifdef CONFIG_PERF_EVENTS
1752 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1753 kretprobe_perf_func(tk, ri, regs);
1755 return 0; /* We don't tweek kernel, so just return 0 */
1757 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1759 static struct trace_event_functions kretprobe_funcs = {
1760 .trace = print_kretprobe_event
1763 static struct trace_event_functions kprobe_funcs = {
1764 .trace = print_kprobe_event
1767 static struct trace_event_fields kretprobe_fields_array[] = {
1768 { .type = TRACE_FUNCTION_TYPE,
1769 .define_fields = kretprobe_event_define_fields },
1773 static struct trace_event_fields kprobe_fields_array[] = {
1774 { .type = TRACE_FUNCTION_TYPE,
1775 .define_fields = kprobe_event_define_fields },
1779 static inline void init_trace_event_call(struct trace_kprobe *tk)
1781 struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1783 if (trace_kprobe_is_return(tk)) {
1784 call->event.funcs = &kretprobe_funcs;
1785 call->class->fields_array = kretprobe_fields_array;
1787 call->event.funcs = &kprobe_funcs;
1788 call->class->fields_array = kprobe_fields_array;
1791 call->flags = TRACE_EVENT_FL_KPROBE;
1792 call->class->reg = kprobe_register;
1795 static int register_kprobe_event(struct trace_kprobe *tk)
1797 init_trace_event_call(tk);
1799 return trace_probe_register_event_call(&tk->tp);
1802 static int unregister_kprobe_event(struct trace_kprobe *tk)
1804 return trace_probe_unregister_event_call(&tk->tp);
1807 #ifdef CONFIG_PERF_EVENTS
1808 /* create a trace_kprobe, but don't add it to global lists */
1809 struct trace_event_call *
1810 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1813 struct trace_kprobe *tk;
1818 * local trace_kprobes are not added to dyn_event, so they are never
1819 * searched in find_trace_kprobe(). Therefore, there is no concern of
1820 * duplicated name here.
1822 event = func ? func : "DUMMY_EVENT";
1824 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1825 offs, 0 /* maxactive */, 0 /* nargs */,
1829 pr_info("Failed to allocate trace_probe.(%d)\n",
1831 return ERR_CAST(tk);
1834 init_trace_event_call(tk);
1836 if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
1841 ret = __register_trace_kprobe(tk);
1845 return trace_probe_event_call(&tk->tp);
1847 free_trace_kprobe(tk);
1848 return ERR_PTR(ret);
1851 void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1853 struct trace_kprobe *tk;
1855 tk = trace_kprobe_primary_from_call(event_call);
1859 if (trace_probe_is_enabled(&tk->tp)) {
1864 __unregister_trace_kprobe(tk);
1866 free_trace_kprobe(tk);
1868 #endif /* CONFIG_PERF_EVENTS */
1870 static __init void enable_boot_kprobe_events(void)
1872 struct trace_array *tr = top_trace_array();
1873 struct trace_event_file *file;
1874 struct trace_kprobe *tk;
1875 struct dyn_event *pos;
1877 mutex_lock(&event_mutex);
1878 for_each_trace_kprobe(tk, pos) {
1879 list_for_each_entry(file, &tr->events, list)
1880 if (file->event_call == trace_probe_event_call(&tk->tp))
1881 trace_event_enable_disable(file, 1, 0);
1883 mutex_unlock(&event_mutex);
1886 static __init void setup_boot_kprobe_events(void)
1888 char *p, *cmd = kprobe_boot_events_buf;
1891 strreplace(kprobe_boot_events_buf, ',', ' ');
1893 while (cmd && *cmd != '\0') {
1894 p = strchr(cmd, ';');
1898 ret = trace_run_command(cmd, create_or_delete_trace_kprobe);
1900 pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1905 enable_boot_kprobe_events();
1909 * Register dynevent at core_initcall. This allows kernel to setup kprobe
1910 * events in postcore_initcall without tracefs.
1912 static __init int init_kprobe_trace_early(void)
1916 ret = dyn_event_register(&trace_kprobe_ops);
1920 if (register_module_notifier(&trace_kprobe_module_nb))
1925 core_initcall(init_kprobe_trace_early);
1927 /* Make a tracefs interface for controlling probe points */
1928 static __init int init_kprobe_trace(void)
1931 struct dentry *entry;
1933 ret = tracing_init_dentry();
1937 entry = tracefs_create_file("kprobe_events", 0644, NULL,
1938 NULL, &kprobe_events_ops);
1940 /* Event list interface */
1942 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1944 /* Profile interface */
1945 entry = tracefs_create_file("kprobe_profile", 0444, NULL,
1946 NULL, &kprobe_profile_ops);
1949 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1951 setup_boot_kprobe_events();
1955 fs_initcall(init_kprobe_trace);
1958 #ifdef CONFIG_FTRACE_STARTUP_TEST
1959 static __init struct trace_event_file *
1960 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1962 struct trace_event_file *file;
1964 list_for_each_entry(file, &tr->events, list)
1965 if (file->event_call == trace_probe_event_call(&tk->tp))
1972 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1973 * stage, we can do this lockless.
1975 static __init int kprobe_trace_self_tests_init(void)
1978 int (*target)(int, int, int, int, int, int);
1979 struct trace_kprobe *tk;
1980 struct trace_event_file *file;
1982 if (tracing_is_disabled())
1985 if (tracing_selftest_disabled)
1988 target = kprobe_trace_selftest_target;
1990 pr_info("Testing kprobe tracing: ");
1992 ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
1993 create_or_delete_trace_kprobe);
1994 if (WARN_ON_ONCE(ret)) {
1995 pr_warn("error on probing function entry.\n");
1998 /* Enable trace point */
1999 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2000 if (WARN_ON_ONCE(tk == NULL)) {
2001 pr_warn("error on getting new probe.\n");
2004 file = find_trace_probe_file(tk, top_trace_array());
2005 if (WARN_ON_ONCE(file == NULL)) {
2006 pr_warn("error on getting probe file.\n");
2009 enable_trace_kprobe(
2010 trace_probe_event_call(&tk->tp), file);
2014 ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
2015 create_or_delete_trace_kprobe);
2016 if (WARN_ON_ONCE(ret)) {
2017 pr_warn("error on probing function return.\n");
2020 /* Enable trace point */
2021 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2022 if (WARN_ON_ONCE(tk == NULL)) {
2023 pr_warn("error on getting 2nd new probe.\n");
2026 file = find_trace_probe_file(tk, top_trace_array());
2027 if (WARN_ON_ONCE(file == NULL)) {
2028 pr_warn("error on getting probe file.\n");
2031 enable_trace_kprobe(
2032 trace_probe_event_call(&tk->tp), file);
2039 ret = target(1, 2, 3, 4, 5, 6);
2042 * Not expecting an error here, the check is only to prevent the
2043 * optimizer from removing the call to target() as otherwise there
2044 * are no side-effects and the call is never performed.
2049 /* Disable trace points before removing it */
2050 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2051 if (WARN_ON_ONCE(tk == NULL)) {
2052 pr_warn("error on getting test probe.\n");
2055 if (trace_kprobe_nhit(tk) != 1) {
2056 pr_warn("incorrect number of testprobe hits\n");
2060 file = find_trace_probe_file(tk, top_trace_array());
2061 if (WARN_ON_ONCE(file == NULL)) {
2062 pr_warn("error on getting probe file.\n");
2065 disable_trace_kprobe(
2066 trace_probe_event_call(&tk->tp), file);
2069 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2070 if (WARN_ON_ONCE(tk == NULL)) {
2071 pr_warn("error on getting 2nd test probe.\n");
2074 if (trace_kprobe_nhit(tk) != 1) {
2075 pr_warn("incorrect number of testprobe2 hits\n");
2079 file = find_trace_probe_file(tk, top_trace_array());
2080 if (WARN_ON_ONCE(file == NULL)) {
2081 pr_warn("error on getting probe file.\n");
2084 disable_trace_kprobe(
2085 trace_probe_event_call(&tk->tp), file);
2088 ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
2089 if (WARN_ON_ONCE(ret)) {
2090 pr_warn("error on deleting a probe.\n");
2094 ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe);
2095 if (WARN_ON_ONCE(ret)) {
2096 pr_warn("error on deleting a probe.\n");
2101 ret = dyn_events_release_all(&trace_kprobe_ops);
2102 if (WARN_ON_ONCE(ret)) {
2103 pr_warn("error on cleaning up probes.\n");
2107 * Wait for the optimizer work to finish. Otherwise it might fiddle
2108 * with probes in already freed __init text.
2110 wait_for_kprobe_optimizer();
2112 pr_cont("NG: Some tests are failed. Please check them.\n");
2118 late_initcall(kprobe_trace_self_tests_init);