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
;
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
, false);
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(unsigned long addr
)
439 unsigned long offset
, size
;
441 if (!addr
|| !kallsyms_lookup_size_offset(addr
, &size
, &offset
))
444 /* Get the entry address of the target function */
448 * Since ftrace_location_range() does inclusive range check, we need
449 * to subtract 1 byte from the end address.
451 return !ftrace_location_range(addr
, addr
+ size
- 1);
454 static bool within_notrace_func(struct trace_kprobe
*tk
)
456 unsigned long addr
= addr
= trace_kprobe_address(tk
);
457 char symname
[KSYM_NAME_LEN
], *p
;
459 if (!__within_notrace_func(addr
))
462 /* Check if the address is on a suffixed-symbol */
463 if (!lookup_symbol_name(addr
, symname
)) {
464 p
= strchr(symname
, '.');
468 addr
= (unsigned long)kprobe_lookup_name(symname
, 0);
470 return __within_notrace_func(addr
);
476 #define within_notrace_func(tk) (false)
479 /* Internal register function - just handle k*probes and flags */
480 static int __register_trace_kprobe(struct trace_kprobe
*tk
)
484 ret
= security_locked_down(LOCKDOWN_KPROBES
);
488 if (trace_kprobe_is_registered(tk
))
491 if (within_notrace_func(tk
)) {
492 pr_warn("Could not probe notrace function %s\n",
493 trace_kprobe_symbol(tk
));
497 for (i
= 0; i
< tk
->tp
.nr_args
; i
++) {
498 ret
= traceprobe_update_arg(&tk
->tp
.args
[i
]);
503 /* Set/clear disabled flag according to tp->flag */
504 if (trace_probe_is_enabled(&tk
->tp
))
505 tk
->rp
.kp
.flags
&= ~KPROBE_FLAG_DISABLED
;
507 tk
->rp
.kp
.flags
|= KPROBE_FLAG_DISABLED
;
509 if (trace_kprobe_is_return(tk
))
510 ret
= register_kretprobe(&tk
->rp
);
512 ret
= register_kprobe(&tk
->rp
.kp
);
517 /* Internal unregister function - just handle k*probes and flags */
518 static void __unregister_trace_kprobe(struct trace_kprobe
*tk
)
520 if (trace_kprobe_is_registered(tk
)) {
521 if (trace_kprobe_is_return(tk
))
522 unregister_kretprobe(&tk
->rp
);
524 unregister_kprobe(&tk
->rp
.kp
);
525 /* Cleanup kprobe for reuse and mark it unregistered */
526 INIT_HLIST_NODE(&tk
->rp
.kp
.hlist
);
527 INIT_LIST_HEAD(&tk
->rp
.kp
.list
);
528 if (tk
->rp
.kp
.symbol_name
)
529 tk
->rp
.kp
.addr
= NULL
;
533 /* Unregister a trace_probe and probe_event */
534 static int unregister_trace_kprobe(struct trace_kprobe
*tk
)
536 /* If other probes are on the event, just unregister kprobe */
537 if (trace_probe_has_sibling(&tk
->tp
))
540 /* Enabled event can not be unregistered */
541 if (trace_probe_is_enabled(&tk
->tp
))
544 /* Will fail if probe is being used by ftrace or perf */
545 if (unregister_kprobe_event(tk
))
549 __unregister_trace_kprobe(tk
);
550 dyn_event_remove(&tk
->devent
);
551 trace_probe_unlink(&tk
->tp
);
556 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe
*orig
,
557 struct trace_kprobe
*comp
)
559 struct trace_probe_event
*tpe
= orig
->tp
.event
;
560 struct trace_probe
*pos
;
563 list_for_each_entry(pos
, &tpe
->probes
, list
) {
564 orig
= container_of(pos
, struct trace_kprobe
, tp
);
565 if (strcmp(trace_kprobe_symbol(orig
),
566 trace_kprobe_symbol(comp
)) ||
567 trace_kprobe_offset(orig
) != trace_kprobe_offset(comp
))
571 * trace_probe_compare_arg_type() ensured that nr_args and
572 * each argument name and type are same. Let's compare comm.
574 for (i
= 0; i
< orig
->tp
.nr_args
; i
++) {
575 if (strcmp(orig
->tp
.args
[i
].comm
,
576 comp
->tp
.args
[i
].comm
))
580 if (i
== orig
->tp
.nr_args
)
587 static int append_trace_kprobe(struct trace_kprobe
*tk
, struct trace_kprobe
*to
)
591 ret
= trace_probe_compare_arg_type(&tk
->tp
, &to
->tp
);
593 /* Note that argument starts index = 2 */
594 trace_probe_log_set_index(ret
+ 1);
595 trace_probe_log_err(0, DIFF_ARG_TYPE
);
598 if (trace_kprobe_has_same_kprobe(to
, tk
)) {
599 trace_probe_log_set_index(0);
600 trace_probe_log_err(0, SAME_PROBE
);
604 /* Append to existing event */
605 ret
= trace_probe_append(&tk
->tp
, &to
->tp
);
609 /* Register k*probe */
610 ret
= __register_trace_kprobe(tk
);
611 if (ret
== -ENOENT
&& !trace_kprobe_module_exist(tk
)) {
612 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
617 trace_probe_unlink(&tk
->tp
);
619 dyn_event_add(&tk
->devent
);
624 /* Register a trace_probe and probe_event */
625 static int register_trace_kprobe(struct trace_kprobe
*tk
)
627 struct trace_kprobe
*old_tk
;
630 mutex_lock(&event_mutex
);
632 old_tk
= find_trace_kprobe(trace_probe_name(&tk
->tp
),
633 trace_probe_group_name(&tk
->tp
));
635 if (trace_kprobe_is_return(tk
) != trace_kprobe_is_return(old_tk
)) {
636 trace_probe_log_set_index(0);
637 trace_probe_log_err(0, DIFF_PROBE_TYPE
);
640 ret
= append_trace_kprobe(tk
, old_tk
);
645 /* Register new event */
646 ret
= register_kprobe_event(tk
);
648 pr_warn("Failed to register probe event(%d)\n", ret
);
652 /* Register k*probe */
653 ret
= __register_trace_kprobe(tk
);
654 if (ret
== -ENOENT
&& !trace_kprobe_module_exist(tk
)) {
655 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
660 unregister_kprobe_event(tk
);
662 dyn_event_add(&tk
->devent
);
665 mutex_unlock(&event_mutex
);
669 /* Module notifier call back, checking event on the module */
670 static int trace_kprobe_module_callback(struct notifier_block
*nb
,
671 unsigned long val
, void *data
)
673 struct module
*mod
= data
;
674 struct dyn_event
*pos
;
675 struct trace_kprobe
*tk
;
678 if (val
!= MODULE_STATE_COMING
)
681 /* Update probes on coming module */
682 mutex_lock(&event_mutex
);
683 for_each_trace_kprobe(tk
, pos
) {
684 if (trace_kprobe_within_module(tk
, mod
)) {
685 /* Don't need to check busy - this should have gone. */
686 __unregister_trace_kprobe(tk
);
687 ret
= __register_trace_kprobe(tk
);
689 pr_warn("Failed to re-register probe %s on %s: %d\n",
690 trace_probe_name(&tk
->tp
),
694 mutex_unlock(&event_mutex
);
699 static struct notifier_block trace_kprobe_module_nb
= {
700 .notifier_call
= trace_kprobe_module_callback
,
701 .priority
= 1 /* Invoked after kprobe module callback */
704 /* Convert certain expected symbols into '_' when generating event names */
705 static inline void sanitize_event_name(char *name
)
707 while (*name
++ != '\0')
708 if (*name
== ':' || *name
== '.')
712 static int trace_kprobe_create(int argc
, const char *argv
[])
717 * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
719 * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
721 * $retval : fetch return value
722 * $stack : fetch stack address
723 * $stackN : fetch Nth of stack (N:0-)
724 * $comm : fetch current task comm
725 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
726 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
727 * %REG : fetch register REG
728 * Dereferencing memory fetch:
729 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
730 * Alias name of args:
731 * NAME=FETCHARG : set NAME as alias of FETCHARG.
733 * FETCHARG:TYPE : use TYPE instead of unsigned long.
735 struct trace_kprobe
*tk
= NULL
;
737 bool is_return
= false;
738 char *symbol
= NULL
, *tmp
= NULL
;
739 const char *event
= NULL
, *group
= KPROBE_EVENT_SYSTEM
;
743 char buf
[MAX_EVENT_NAME_LEN
];
744 unsigned int flags
= TPARG_FL_KERNEL
;
746 switch (argv
[0][0]) {
749 flags
|= TPARG_FL_RETURN
;
759 trace_probe_log_init("trace_kprobe", argc
, argv
);
761 event
= strchr(&argv
[0][1], ':');
765 if (isdigit(argv
[0][1])) {
767 trace_probe_log_err(1, MAXACT_NO_KPROBE
);
771 len
= event
- &argv
[0][1] - 1;
773 len
= strlen(&argv
[0][1]);
774 if (len
> MAX_EVENT_NAME_LEN
- 1) {
775 trace_probe_log_err(1, BAD_MAXACT
);
778 memcpy(buf
, &argv
[0][1], len
);
780 ret
= kstrtouint(buf
, 0, &maxactive
);
781 if (ret
|| !maxactive
) {
782 trace_probe_log_err(1, BAD_MAXACT
);
785 /* kretprobes instances are iterated over via a list. The
786 * maximum should stay reasonable.
788 if (maxactive
> KRETPROBE_MAXACTIVE_MAX
) {
789 trace_probe_log_err(1, MAXACT_TOO_BIG
);
794 /* try to parse an address. if that fails, try to read the
795 * input as a symbol. */
796 if (kstrtoul(argv
[1], 0, (unsigned long *)&addr
)) {
797 trace_probe_log_set_index(1);
798 /* Check whether uprobe event specified */
799 if (strchr(argv
[1], '/') && strchr(argv
[1], ':')) {
803 /* a symbol specified */
804 symbol
= kstrdup(argv
[1], GFP_KERNEL
);
807 /* TODO: support .init module functions */
808 ret
= traceprobe_split_symbol_offset(symbol
, &offset
);
809 if (ret
|| offset
< 0 || offset
> UINT_MAX
) {
810 trace_probe_log_err(0, BAD_PROBE_ADDR
);
813 if (kprobe_on_func_entry(NULL
, symbol
, offset
))
814 flags
|= TPARG_FL_FENTRY
;
815 if (offset
&& is_return
&& !(flags
& TPARG_FL_FENTRY
)) {
816 trace_probe_log_err(0, BAD_RETPROBE
);
821 trace_probe_log_set_index(0);
823 ret
= traceprobe_parse_event_name(&event
, &group
, buf
,
828 /* Make a new event name */
830 snprintf(buf
, MAX_EVENT_NAME_LEN
, "%c_%s_%ld",
831 is_return
? 'r' : 'p', symbol
, offset
);
833 snprintf(buf
, MAX_EVENT_NAME_LEN
, "%c_0x%p",
834 is_return
? 'r' : 'p', addr
);
835 sanitize_event_name(buf
);
840 tk
= alloc_trace_kprobe(group
, event
, addr
, symbol
, offset
, maxactive
,
841 argc
- 2, is_return
);
844 /* This must return -ENOMEM, else there is a bug */
845 WARN_ON_ONCE(ret
!= -ENOMEM
);
846 goto out
; /* We know tk is not allocated */
848 argc
-= 2; argv
+= 2;
850 /* parse arguments */
851 for (i
= 0; i
< argc
&& i
< MAX_TRACE_ARGS
; i
++) {
852 tmp
= kstrdup(argv
[i
], GFP_KERNEL
);
858 trace_probe_log_set_index(i
+ 2);
859 ret
= traceprobe_parse_probe_arg(&tk
->tp
, i
, tmp
, flags
);
862 goto error
; /* This can be -ENOMEM */
865 ret
= traceprobe_set_print_fmt(&tk
->tp
, is_return
);
869 ret
= register_trace_kprobe(tk
);
871 trace_probe_log_set_index(1);
873 trace_probe_log_err(0, BAD_INSN_BNDRY
);
874 else if (ret
== -ENOENT
)
875 trace_probe_log_err(0, BAD_PROBE_ADDR
);
876 else if (ret
!= -ENOMEM
&& ret
!= -EEXIST
)
877 trace_probe_log_err(0, FAIL_REG_PROBE
);
882 trace_probe_log_clear();
889 free_trace_kprobe(tk
);
893 static int create_or_delete_trace_kprobe(int argc
, char **argv
)
897 if (argv
[0][0] == '-')
898 return dyn_event_release(argc
, argv
, &trace_kprobe_ops
);
900 ret
= trace_kprobe_create(argc
, (const char **)argv
);
901 return ret
== -ECANCELED
? -EINVAL
: ret
;
904 static int trace_kprobe_run_command(struct dynevent_cmd
*cmd
)
906 return trace_run_command(cmd
->seq
.buffer
, create_or_delete_trace_kprobe
);
910 * kprobe_event_cmd_init - Initialize a kprobe event command object
911 * @cmd: A pointer to the dynevent_cmd struct representing the new event
912 * @buf: A pointer to the buffer used to build the command
913 * @maxlen: The length of the buffer passed in @buf
915 * Initialize a synthetic event command object. Use this before
916 * calling any of the other kprobe_event functions.
918 void kprobe_event_cmd_init(struct dynevent_cmd
*cmd
, char *buf
, int maxlen
)
920 dynevent_cmd_init(cmd
, buf
, maxlen
, DYNEVENT_TYPE_KPROBE
,
921 trace_kprobe_run_command
);
923 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init
);
926 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
927 * @cmd: A pointer to the dynevent_cmd struct representing the new event
928 * @name: The name of the kprobe event
929 * @loc: The location of the kprobe event
930 * @kretprobe: Is this a return probe?
931 * @args: Variable number of arg (pairs), one pair for each field
933 * NOTE: Users normally won't want to call this function directly, but
934 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
935 * adds a NULL to the end of the arg list. If this function is used
936 * directly, make sure the last arg in the variable arg list is NULL.
938 * Generate a kprobe event command to be executed by
939 * kprobe_event_gen_cmd_end(). This function can be used to generate the
940 * complete command or only the first part of it; in the latter case,
941 * kprobe_event_add_fields() can be used to add more fields following this.
943 * Return: 0 if successful, error otherwise.
945 int __kprobe_event_gen_cmd_start(struct dynevent_cmd
*cmd
, bool kretprobe
,
946 const char *name
, const char *loc
, ...)
948 char buf
[MAX_EVENT_NAME_LEN
];
949 struct dynevent_arg arg
;
953 if (cmd
->type
!= DYNEVENT_TYPE_KPROBE
)
957 snprintf(buf
, MAX_EVENT_NAME_LEN
, "r:kprobes/%s", name
);
959 snprintf(buf
, MAX_EVENT_NAME_LEN
, "p:kprobes/%s", name
);
961 ret
= dynevent_str_add(cmd
, buf
);
965 dynevent_arg_init(&arg
, 0);
967 ret
= dynevent_arg_add(cmd
, &arg
, NULL
);
975 field
= va_arg(args
, const char *);
979 if (++cmd
->n_fields
> MAX_TRACE_ARGS
) {
985 ret
= dynevent_arg_add(cmd
, &arg
, NULL
);
993 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start
);
996 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
997 * @cmd: A pointer to the dynevent_cmd struct representing the new event
998 * @args: Variable number of arg (pairs), one pair for each field
1000 * NOTE: Users normally won't want to call this function directly, but
1001 * rather use the kprobe_event_add_fields() wrapper, which
1002 * automatically adds a NULL to the end of the arg list. If this
1003 * function is used directly, make sure the last arg in the variable
1006 * Add probe fields to an existing kprobe command using a variable
1007 * list of args. Fields are added in the same order they're listed.
1009 * Return: 0 if successful, error otherwise.
1011 int __kprobe_event_add_fields(struct dynevent_cmd
*cmd
, ...)
1013 struct dynevent_arg arg
;
1017 if (cmd
->type
!= DYNEVENT_TYPE_KPROBE
)
1020 dynevent_arg_init(&arg
, 0);
1022 va_start(args
, cmd
);
1026 field
= va_arg(args
, const char *);
1030 if (++cmd
->n_fields
> MAX_TRACE_ARGS
) {
1036 ret
= dynevent_arg_add(cmd
, &arg
, NULL
);
1044 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields
);
1047 * kprobe_event_delete - Delete a kprobe event
1048 * @name: The name of the kprobe event to delete
1050 * Delete a kprobe event with the give @name from kernel code rather
1051 * than directly from the command line.
1053 * Return: 0 if successful, error otherwise.
1055 int kprobe_event_delete(const char *name
)
1057 char buf
[MAX_EVENT_NAME_LEN
];
1059 snprintf(buf
, MAX_EVENT_NAME_LEN
, "-:%s", name
);
1061 return trace_run_command(buf
, create_or_delete_trace_kprobe
);
1063 EXPORT_SYMBOL_GPL(kprobe_event_delete
);
1065 static int trace_kprobe_release(struct dyn_event
*ev
)
1067 struct trace_kprobe
*tk
= to_trace_kprobe(ev
);
1068 int ret
= unregister_trace_kprobe(tk
);
1071 free_trace_kprobe(tk
);
1075 static int trace_kprobe_show(struct seq_file
*m
, struct dyn_event
*ev
)
1077 struct trace_kprobe
*tk
= to_trace_kprobe(ev
);
1080 seq_putc(m
, trace_kprobe_is_return(tk
) ? 'r' : 'p');
1081 if (trace_kprobe_is_return(tk
) && tk
->rp
.maxactive
)
1082 seq_printf(m
, "%d", tk
->rp
.maxactive
);
1083 seq_printf(m
, ":%s/%s", trace_probe_group_name(&tk
->tp
),
1084 trace_probe_name(&tk
->tp
));
1087 seq_printf(m
, " 0x%p", tk
->rp
.kp
.addr
);
1088 else if (tk
->rp
.kp
.offset
)
1089 seq_printf(m
, " %s+%u", trace_kprobe_symbol(tk
),
1092 seq_printf(m
, " %s", trace_kprobe_symbol(tk
));
1094 for (i
= 0; i
< tk
->tp
.nr_args
; i
++)
1095 seq_printf(m
, " %s=%s", tk
->tp
.args
[i
].name
, tk
->tp
.args
[i
].comm
);
1101 static int probes_seq_show(struct seq_file
*m
, void *v
)
1103 struct dyn_event
*ev
= v
;
1105 if (!is_trace_kprobe(ev
))
1108 return trace_kprobe_show(m
, ev
);
1111 static const struct seq_operations probes_seq_op
= {
1112 .start
= dyn_event_seq_start
,
1113 .next
= dyn_event_seq_next
,
1114 .stop
= dyn_event_seq_stop
,
1115 .show
= probes_seq_show
1118 static int probes_open(struct inode
*inode
, struct file
*file
)
1122 ret
= security_locked_down(LOCKDOWN_TRACEFS
);
1126 if ((file
->f_mode
& FMODE_WRITE
) && (file
->f_flags
& O_TRUNC
)) {
1127 ret
= dyn_events_release_all(&trace_kprobe_ops
);
1132 return seq_open(file
, &probes_seq_op
);
1135 static ssize_t
probes_write(struct file
*file
, const char __user
*buffer
,
1136 size_t count
, loff_t
*ppos
)
1138 return trace_parse_run_command(file
, buffer
, count
, ppos
,
1139 create_or_delete_trace_kprobe
);
1142 static const struct file_operations kprobe_events_ops
= {
1143 .owner
= THIS_MODULE
,
1144 .open
= probes_open
,
1146 .llseek
= seq_lseek
,
1147 .release
= seq_release
,
1148 .write
= probes_write
,
1151 /* Probes profiling interfaces */
1152 static int probes_profile_seq_show(struct seq_file
*m
, void *v
)
1154 struct dyn_event
*ev
= v
;
1155 struct trace_kprobe
*tk
;
1157 if (!is_trace_kprobe(ev
))
1160 tk
= to_trace_kprobe(ev
);
1161 seq_printf(m
, " %-44s %15lu %15lu\n",
1162 trace_probe_name(&tk
->tp
),
1163 trace_kprobe_nhit(tk
),
1169 static const struct seq_operations profile_seq_op
= {
1170 .start
= dyn_event_seq_start
,
1171 .next
= dyn_event_seq_next
,
1172 .stop
= dyn_event_seq_stop
,
1173 .show
= probes_profile_seq_show
1176 static int profile_open(struct inode
*inode
, struct file
*file
)
1180 ret
= security_locked_down(LOCKDOWN_TRACEFS
);
1184 return seq_open(file
, &profile_seq_op
);
1187 static const struct file_operations kprobe_profile_ops
= {
1188 .owner
= THIS_MODULE
,
1189 .open
= profile_open
,
1191 .llseek
= seq_lseek
,
1192 .release
= seq_release
,
1195 /* Kprobe specific fetch functions */
1197 /* Return the length of string -- including null terminal byte */
1198 static nokprobe_inline
int
1199 fetch_store_strlen(unsigned long addr
)
1205 ret
= probe_kernel_read(&c
, (u8
*)addr
+ len
, 1);
1207 } while (c
&& ret
== 0 && len
< MAX_STRING_SIZE
);
1209 return (ret
< 0) ? ret
: len
;
1212 /* Return the length of string -- including null terminal byte */
1213 static nokprobe_inline
int
1214 fetch_store_strlen_user(unsigned long addr
)
1216 const void __user
*uaddr
= (__force
const void __user
*)addr
;
1218 return strnlen_unsafe_user(uaddr
, MAX_STRING_SIZE
);
1222 * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
1223 * length and relative data location.
1225 static nokprobe_inline
int
1226 fetch_store_string(unsigned long addr
, void *dest
, void *base
)
1228 int maxlen
= get_loc_len(*(u32
*)dest
);
1232 if (unlikely(!maxlen
))
1235 __dest
= get_loc_data(dest
, base
);
1238 * Try to get string again, since the string can be changed while
1241 ret
= strncpy_from_unsafe(__dest
, (void *)addr
, maxlen
);
1243 *(u32
*)dest
= make_data_loc(ret
, __dest
- base
);
1249 * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
1250 * with max length and relative data location.
1252 static nokprobe_inline
int
1253 fetch_store_string_user(unsigned long addr
, void *dest
, void *base
)
1255 const void __user
*uaddr
= (__force
const void __user
*)addr
;
1256 int maxlen
= get_loc_len(*(u32
*)dest
);
1260 if (unlikely(!maxlen
))
1263 __dest
= get_loc_data(dest
, base
);
1265 ret
= strncpy_from_unsafe_user(__dest
, uaddr
, maxlen
);
1267 *(u32
*)dest
= make_data_loc(ret
, __dest
- base
);
1272 static nokprobe_inline
int
1273 probe_mem_read(void *dest
, void *src
, size_t size
)
1275 return probe_kernel_read(dest
, src
, size
);
1278 static nokprobe_inline
int
1279 probe_mem_read_user(void *dest
, void *src
, size_t size
)
1281 const void __user
*uaddr
= (__force
const void __user
*)src
;
1283 return probe_user_read(dest
, uaddr
, size
);
1286 /* Note that we don't verify it, since the code does not come from user space */
1288 process_fetch_insn(struct fetch_insn
*code
, struct pt_regs
*regs
, void *dest
,
1294 /* 1st stage: get value from context */
1297 val
= regs_get_register(regs
, code
->param
);
1299 case FETCH_OP_STACK
:
1300 val
= regs_get_kernel_stack_nth(regs
, code
->param
);
1302 case FETCH_OP_STACKP
:
1303 val
= kernel_stack_pointer(regs
);
1305 case FETCH_OP_RETVAL
:
1306 val
= regs_return_value(regs
);
1309 val
= code
->immediate
;
1312 val
= (unsigned long)current
->comm
;
1315 val
= (unsigned long)code
->data
;
1317 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1319 val
= regs_get_kernel_argument(regs
, code
->param
);
1322 case FETCH_NOP_SYMBOL
: /* Ignore a place holder */
1330 return process_fetch_insn_bottom(code
, val
, dest
, base
);
1332 NOKPROBE_SYMBOL(process_fetch_insn
)
1334 /* Kprobe handler */
1335 static nokprobe_inline
void
1336 __kprobe_trace_func(struct trace_kprobe
*tk
, struct pt_regs
*regs
,
1337 struct trace_event_file
*trace_file
)
1339 struct kprobe_trace_entry_head
*entry
;
1340 struct trace_event_call
*call
= trace_probe_event_call(&tk
->tp
);
1341 struct trace_event_buffer fbuffer
;
1344 WARN_ON(call
!= trace_file
->event_call
);
1346 if (trace_trigger_soft_disabled(trace_file
))
1349 local_save_flags(fbuffer
.flags
);
1350 fbuffer
.pc
= preempt_count();
1351 fbuffer
.trace_file
= trace_file
;
1353 dsize
= __get_data_size(&tk
->tp
, regs
);
1356 trace_event_buffer_lock_reserve(&fbuffer
.buffer
, trace_file
,
1358 sizeof(*entry
) + tk
->tp
.size
+ dsize
,
1359 fbuffer
.flags
, fbuffer
.pc
);
1363 fbuffer
.regs
= regs
;
1364 entry
= fbuffer
.entry
= ring_buffer_event_data(fbuffer
.event
);
1365 entry
->ip
= (unsigned long)tk
->rp
.kp
.addr
;
1366 store_trace_args(&entry
[1], &tk
->tp
, regs
, sizeof(*entry
), dsize
);
1368 trace_event_buffer_commit(&fbuffer
);
1372 kprobe_trace_func(struct trace_kprobe
*tk
, struct pt_regs
*regs
)
1374 struct event_file_link
*link
;
1376 trace_probe_for_each_link_rcu(link
, &tk
->tp
)
1377 __kprobe_trace_func(tk
, regs
, link
->file
);
1379 NOKPROBE_SYMBOL(kprobe_trace_func
);
1381 /* Kretprobe handler */
1382 static nokprobe_inline
void
1383 __kretprobe_trace_func(struct trace_kprobe
*tk
, struct kretprobe_instance
*ri
,
1384 struct pt_regs
*regs
,
1385 struct trace_event_file
*trace_file
)
1387 struct kretprobe_trace_entry_head
*entry
;
1388 struct trace_event_buffer fbuffer
;
1389 struct trace_event_call
*call
= trace_probe_event_call(&tk
->tp
);
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
);
1403 trace_event_buffer_lock_reserve(&fbuffer
.buffer
, trace_file
,
1405 sizeof(*entry
) + tk
->tp
.size
+ dsize
,
1406 fbuffer
.flags
, fbuffer
.pc
);
1410 fbuffer
.regs
= regs
;
1411 entry
= fbuffer
.entry
= ring_buffer_event_data(fbuffer
.event
);
1412 entry
->func
= (unsigned long)tk
->rp
.kp
.addr
;
1413 entry
->ret_ip
= (unsigned long)ri
->ret_addr
;
1414 store_trace_args(&entry
[1], &tk
->tp
, regs
, sizeof(*entry
), dsize
);
1416 trace_event_buffer_commit(&fbuffer
);
1420 kretprobe_trace_func(struct trace_kprobe
*tk
, struct kretprobe_instance
*ri
,
1421 struct pt_regs
*regs
)
1423 struct event_file_link
*link
;
1425 trace_probe_for_each_link_rcu(link
, &tk
->tp
)
1426 __kretprobe_trace_func(tk
, ri
, regs
, link
->file
);
1428 NOKPROBE_SYMBOL(kretprobe_trace_func
);
1430 /* Event entry printers */
1431 static enum print_line_t
1432 print_kprobe_event(struct trace_iterator
*iter
, int flags
,
1433 struct trace_event
*event
)
1435 struct kprobe_trace_entry_head
*field
;
1436 struct trace_seq
*s
= &iter
->seq
;
1437 struct trace_probe
*tp
;
1439 field
= (struct kprobe_trace_entry_head
*)iter
->ent
;
1440 tp
= trace_probe_primary_from_call(
1441 container_of(event
, struct trace_event_call
, event
));
1442 if (WARN_ON_ONCE(!tp
))
1445 trace_seq_printf(s
, "%s: (", trace_probe_name(tp
));
1447 if (!seq_print_ip_sym(s
, field
->ip
, flags
| TRACE_ITER_SYM_OFFSET
))
1450 trace_seq_putc(s
, ')');
1452 if (print_probe_args(s
, tp
->args
, tp
->nr_args
,
1453 (u8
*)&field
[1], field
) < 0)
1456 trace_seq_putc(s
, '\n');
1458 return trace_handle_return(s
);
1461 static enum print_line_t
1462 print_kretprobe_event(struct trace_iterator
*iter
, int flags
,
1463 struct trace_event
*event
)
1465 struct kretprobe_trace_entry_head
*field
;
1466 struct trace_seq
*s
= &iter
->seq
;
1467 struct trace_probe
*tp
;
1469 field
= (struct kretprobe_trace_entry_head
*)iter
->ent
;
1470 tp
= trace_probe_primary_from_call(
1471 container_of(event
, struct trace_event_call
, event
));
1472 if (WARN_ON_ONCE(!tp
))
1475 trace_seq_printf(s
, "%s: (", trace_probe_name(tp
));
1477 if (!seq_print_ip_sym(s
, field
->ret_ip
, flags
| TRACE_ITER_SYM_OFFSET
))
1480 trace_seq_puts(s
, " <- ");
1482 if (!seq_print_ip_sym(s
, field
->func
, flags
& ~TRACE_ITER_SYM_OFFSET
))
1485 trace_seq_putc(s
, ')');
1487 if (print_probe_args(s
, tp
->args
, tp
->nr_args
,
1488 (u8
*)&field
[1], field
) < 0)
1491 trace_seq_putc(s
, '\n');
1494 return trace_handle_return(s
);
1498 static int kprobe_event_define_fields(struct trace_event_call
*event_call
)
1501 struct kprobe_trace_entry_head field
;
1502 struct trace_probe
*tp
;
1504 tp
= trace_probe_primary_from_call(event_call
);
1505 if (WARN_ON_ONCE(!tp
))
1508 DEFINE_FIELD(unsigned long, ip
, FIELD_STRING_IP
, 0);
1510 return traceprobe_define_arg_fields(event_call
, sizeof(field
), tp
);
1513 static int kretprobe_event_define_fields(struct trace_event_call
*event_call
)
1516 struct kretprobe_trace_entry_head field
;
1517 struct trace_probe
*tp
;
1519 tp
= trace_probe_primary_from_call(event_call
);
1520 if (WARN_ON_ONCE(!tp
))
1523 DEFINE_FIELD(unsigned long, func
, FIELD_STRING_FUNC
, 0);
1524 DEFINE_FIELD(unsigned long, ret_ip
, FIELD_STRING_RETIP
, 0);
1526 return traceprobe_define_arg_fields(event_call
, sizeof(field
), tp
);
1529 #ifdef CONFIG_PERF_EVENTS
1531 /* Kprobe profile handler */
1533 kprobe_perf_func(struct trace_kprobe
*tk
, struct pt_regs
*regs
)
1535 struct trace_event_call
*call
= trace_probe_event_call(&tk
->tp
);
1536 struct kprobe_trace_entry_head
*entry
;
1537 struct hlist_head
*head
;
1538 int size
, __size
, dsize
;
1541 if (bpf_prog_array_valid(call
)) {
1542 unsigned long orig_ip
= instruction_pointer(regs
);
1545 ret
= trace_call_bpf(call
, regs
);
1548 * We need to check and see if we modified the pc of the
1549 * pt_regs, and if so return 1 so that we don't do the
1552 if (orig_ip
!= instruction_pointer(regs
))
1558 head
= this_cpu_ptr(call
->perf_events
);
1559 if (hlist_empty(head
))
1562 dsize
= __get_data_size(&tk
->tp
, regs
);
1563 __size
= sizeof(*entry
) + tk
->tp
.size
+ dsize
;
1564 size
= ALIGN(__size
+ sizeof(u32
), sizeof(u64
));
1565 size
-= sizeof(u32
);
1567 entry
= perf_trace_buf_alloc(size
, NULL
, &rctx
);
1571 entry
->ip
= (unsigned long)tk
->rp
.kp
.addr
;
1572 memset(&entry
[1], 0, dsize
);
1573 store_trace_args(&entry
[1], &tk
->tp
, regs
, sizeof(*entry
), dsize
);
1574 perf_trace_buf_submit(entry
, size
, rctx
, call
->event
.type
, 1, regs
,
1578 NOKPROBE_SYMBOL(kprobe_perf_func
);
1580 /* Kretprobe profile handler */
1582 kretprobe_perf_func(struct trace_kprobe
*tk
, struct kretprobe_instance
*ri
,
1583 struct pt_regs
*regs
)
1585 struct trace_event_call
*call
= trace_probe_event_call(&tk
->tp
);
1586 struct kretprobe_trace_entry_head
*entry
;
1587 struct hlist_head
*head
;
1588 int size
, __size
, dsize
;
1591 if (bpf_prog_array_valid(call
) && !trace_call_bpf(call
, regs
))
1594 head
= this_cpu_ptr(call
->perf_events
);
1595 if (hlist_empty(head
))
1598 dsize
= __get_data_size(&tk
->tp
, regs
);
1599 __size
= sizeof(*entry
) + tk
->tp
.size
+ dsize
;
1600 size
= ALIGN(__size
+ sizeof(u32
), sizeof(u64
));
1601 size
-= sizeof(u32
);
1603 entry
= perf_trace_buf_alloc(size
, NULL
, &rctx
);
1607 entry
->func
= (unsigned long)tk
->rp
.kp
.addr
;
1608 entry
->ret_ip
= (unsigned long)ri
->ret_addr
;
1609 store_trace_args(&entry
[1], &tk
->tp
, regs
, sizeof(*entry
), dsize
);
1610 perf_trace_buf_submit(entry
, size
, rctx
, call
->event
.type
, 1, regs
,
1613 NOKPROBE_SYMBOL(kretprobe_perf_func
);
1615 int bpf_get_kprobe_info(const struct perf_event
*event
, u32
*fd_type
,
1616 const char **symbol
, u64
*probe_offset
,
1617 u64
*probe_addr
, bool perf_type_tracepoint
)
1619 const char *pevent
= trace_event_name(event
->tp_event
);
1620 const char *group
= event
->tp_event
->class->system
;
1621 struct trace_kprobe
*tk
;
1623 if (perf_type_tracepoint
)
1624 tk
= find_trace_kprobe(pevent
, group
);
1626 tk
= event
->tp_event
->data
;
1630 *fd_type
= trace_kprobe_is_return(tk
) ? BPF_FD_TYPE_KRETPROBE
1631 : BPF_FD_TYPE_KPROBE
;
1633 *symbol
= tk
->symbol
;
1634 *probe_offset
= tk
->rp
.kp
.offset
;
1639 *probe_addr
= (unsigned long)tk
->rp
.kp
.addr
;
1643 #endif /* CONFIG_PERF_EVENTS */
1646 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1648 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1649 * lockless, but we can't race with this __init function.
1651 static int kprobe_register(struct trace_event_call
*event
,
1652 enum trace_reg type
, void *data
)
1654 struct trace_event_file
*file
= data
;
1657 case TRACE_REG_REGISTER
:
1658 return enable_trace_kprobe(event
, file
);
1659 case TRACE_REG_UNREGISTER
:
1660 return disable_trace_kprobe(event
, file
);
1662 #ifdef CONFIG_PERF_EVENTS
1663 case TRACE_REG_PERF_REGISTER
:
1664 return enable_trace_kprobe(event
, NULL
);
1665 case TRACE_REG_PERF_UNREGISTER
:
1666 return disable_trace_kprobe(event
, NULL
);
1667 case TRACE_REG_PERF_OPEN
:
1668 case TRACE_REG_PERF_CLOSE
:
1669 case TRACE_REG_PERF_ADD
:
1670 case TRACE_REG_PERF_DEL
:
1677 static int kprobe_dispatcher(struct kprobe
*kp
, struct pt_regs
*regs
)
1679 struct trace_kprobe
*tk
= container_of(kp
, struct trace_kprobe
, rp
.kp
);
1682 raw_cpu_inc(*tk
->nhit
);
1684 if (trace_probe_test_flag(&tk
->tp
, TP_FLAG_TRACE
))
1685 kprobe_trace_func(tk
, regs
);
1686 #ifdef CONFIG_PERF_EVENTS
1687 if (trace_probe_test_flag(&tk
->tp
, TP_FLAG_PROFILE
))
1688 ret
= kprobe_perf_func(tk
, regs
);
1692 NOKPROBE_SYMBOL(kprobe_dispatcher
);
1695 kretprobe_dispatcher(struct kretprobe_instance
*ri
, struct pt_regs
*regs
)
1697 struct trace_kprobe
*tk
= container_of(ri
->rp
, struct trace_kprobe
, rp
);
1699 raw_cpu_inc(*tk
->nhit
);
1701 if (trace_probe_test_flag(&tk
->tp
, TP_FLAG_TRACE
))
1702 kretprobe_trace_func(tk
, ri
, regs
);
1703 #ifdef CONFIG_PERF_EVENTS
1704 if (trace_probe_test_flag(&tk
->tp
, TP_FLAG_PROFILE
))
1705 kretprobe_perf_func(tk
, ri
, regs
);
1707 return 0; /* We don't tweek kernel, so just return 0 */
1709 NOKPROBE_SYMBOL(kretprobe_dispatcher
);
1711 static struct trace_event_functions kretprobe_funcs
= {
1712 .trace
= print_kretprobe_event
1715 static struct trace_event_functions kprobe_funcs
= {
1716 .trace
= print_kprobe_event
1719 static struct trace_event_fields kretprobe_fields_array
[] = {
1720 { .type
= TRACE_FUNCTION_TYPE
,
1721 .define_fields
= kretprobe_event_define_fields
},
1725 static struct trace_event_fields kprobe_fields_array
[] = {
1726 { .type
= TRACE_FUNCTION_TYPE
,
1727 .define_fields
= kprobe_event_define_fields
},
1731 static inline void init_trace_event_call(struct trace_kprobe
*tk
)
1733 struct trace_event_call
*call
= trace_probe_event_call(&tk
->tp
);
1735 if (trace_kprobe_is_return(tk
)) {
1736 call
->event
.funcs
= &kretprobe_funcs
;
1737 call
->class->fields_array
= kretprobe_fields_array
;
1739 call
->event
.funcs
= &kprobe_funcs
;
1740 call
->class->fields_array
= kprobe_fields_array
;
1743 call
->flags
= TRACE_EVENT_FL_KPROBE
;
1744 call
->class->reg
= kprobe_register
;
1747 static int register_kprobe_event(struct trace_kprobe
*tk
)
1749 init_trace_event_call(tk
);
1751 return trace_probe_register_event_call(&tk
->tp
);
1754 static int unregister_kprobe_event(struct trace_kprobe
*tk
)
1756 return trace_probe_unregister_event_call(&tk
->tp
);
1759 #ifdef CONFIG_PERF_EVENTS
1760 /* create a trace_kprobe, but don't add it to global lists */
1761 struct trace_event_call
*
1762 create_local_trace_kprobe(char *func
, void *addr
, unsigned long offs
,
1765 struct trace_kprobe
*tk
;
1770 * local trace_kprobes are not added to dyn_event, so they are never
1771 * searched in find_trace_kprobe(). Therefore, there is no concern of
1772 * duplicated name here.
1774 event
= func
? func
: "DUMMY_EVENT";
1776 tk
= alloc_trace_kprobe(KPROBE_EVENT_SYSTEM
, event
, (void *)addr
, func
,
1777 offs
, 0 /* maxactive */, 0 /* nargs */,
1781 pr_info("Failed to allocate trace_probe.(%d)\n",
1783 return ERR_CAST(tk
);
1786 init_trace_event_call(tk
);
1788 if (traceprobe_set_print_fmt(&tk
->tp
, trace_kprobe_is_return(tk
)) < 0) {
1793 ret
= __register_trace_kprobe(tk
);
1797 return trace_probe_event_call(&tk
->tp
);
1799 free_trace_kprobe(tk
);
1800 return ERR_PTR(ret
);
1803 void destroy_local_trace_kprobe(struct trace_event_call
*event_call
)
1805 struct trace_kprobe
*tk
;
1807 tk
= trace_kprobe_primary_from_call(event_call
);
1811 if (trace_probe_is_enabled(&tk
->tp
)) {
1816 __unregister_trace_kprobe(tk
);
1818 free_trace_kprobe(tk
);
1820 #endif /* CONFIG_PERF_EVENTS */
1822 static __init
void enable_boot_kprobe_events(void)
1824 struct trace_array
*tr
= top_trace_array();
1825 struct trace_event_file
*file
;
1826 struct trace_kprobe
*tk
;
1827 struct dyn_event
*pos
;
1829 mutex_lock(&event_mutex
);
1830 for_each_trace_kprobe(tk
, pos
) {
1831 list_for_each_entry(file
, &tr
->events
, list
)
1832 if (file
->event_call
== trace_probe_event_call(&tk
->tp
))
1833 trace_event_enable_disable(file
, 1, 0);
1835 mutex_unlock(&event_mutex
);
1838 static __init
void setup_boot_kprobe_events(void)
1840 char *p
, *cmd
= kprobe_boot_events_buf
;
1843 strreplace(kprobe_boot_events_buf
, ',', ' ');
1845 while (cmd
&& *cmd
!= '\0') {
1846 p
= strchr(cmd
, ';');
1850 ret
= trace_run_command(cmd
, create_or_delete_trace_kprobe
);
1852 pr_warn("Failed to add event(%d): %s\n", ret
, cmd
);
1854 kprobe_boot_events_enabled
= true;
1859 enable_boot_kprobe_events();
1863 * Register dynevent at subsys_initcall. This allows kernel to setup kprobe
1864 * events in fs_initcall without tracefs.
1866 static __init
int init_kprobe_trace_early(void)
1870 ret
= dyn_event_register(&trace_kprobe_ops
);
1874 if (register_module_notifier(&trace_kprobe_module_nb
))
1879 subsys_initcall(init_kprobe_trace_early
);
1881 /* Make a tracefs interface for controlling probe points */
1882 static __init
int init_kprobe_trace(void)
1884 struct dentry
*d_tracer
;
1885 struct dentry
*entry
;
1887 d_tracer
= tracing_init_dentry();
1888 if (IS_ERR(d_tracer
))
1891 entry
= tracefs_create_file("kprobe_events", 0644, d_tracer
,
1892 NULL
, &kprobe_events_ops
);
1894 /* Event list interface */
1896 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1898 /* Profile interface */
1899 entry
= tracefs_create_file("kprobe_profile", 0444, d_tracer
,
1900 NULL
, &kprobe_profile_ops
);
1903 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1905 setup_boot_kprobe_events();
1909 fs_initcall(init_kprobe_trace
);
1912 #ifdef CONFIG_FTRACE_STARTUP_TEST
1913 static __init
struct trace_event_file
*
1914 find_trace_probe_file(struct trace_kprobe
*tk
, struct trace_array
*tr
)
1916 struct trace_event_file
*file
;
1918 list_for_each_entry(file
, &tr
->events
, list
)
1919 if (file
->event_call
== trace_probe_event_call(&tk
->tp
))
1926 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1927 * stage, we can do this lockless.
1929 static __init
int kprobe_trace_self_tests_init(void)
1932 int (*target
)(int, int, int, int, int, int);
1933 struct trace_kprobe
*tk
;
1934 struct trace_event_file
*file
;
1936 if (tracing_is_disabled())
1939 if (kprobe_boot_events_enabled
) {
1940 pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n");
1944 target
= kprobe_trace_selftest_target
;
1946 pr_info("Testing kprobe tracing: ");
1948 ret
= trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
1949 create_or_delete_trace_kprobe
);
1950 if (WARN_ON_ONCE(ret
)) {
1951 pr_warn("error on probing function entry.\n");
1954 /* Enable trace point */
1955 tk
= find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM
);
1956 if (WARN_ON_ONCE(tk
== NULL
)) {
1957 pr_warn("error on getting new probe.\n");
1960 file
= find_trace_probe_file(tk
, top_trace_array());
1961 if (WARN_ON_ONCE(file
== NULL
)) {
1962 pr_warn("error on getting probe file.\n");
1965 enable_trace_kprobe(
1966 trace_probe_event_call(&tk
->tp
), file
);
1970 ret
= trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
1971 create_or_delete_trace_kprobe
);
1972 if (WARN_ON_ONCE(ret
)) {
1973 pr_warn("error on probing function return.\n");
1976 /* Enable trace point */
1977 tk
= find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM
);
1978 if (WARN_ON_ONCE(tk
== NULL
)) {
1979 pr_warn("error on getting 2nd new probe.\n");
1982 file
= find_trace_probe_file(tk
, top_trace_array());
1983 if (WARN_ON_ONCE(file
== NULL
)) {
1984 pr_warn("error on getting probe file.\n");
1987 enable_trace_kprobe(
1988 trace_probe_event_call(&tk
->tp
), file
);
1995 ret
= target(1, 2, 3, 4, 5, 6);
1998 * Not expecting an error here, the check is only to prevent the
1999 * optimizer from removing the call to target() as otherwise there
2000 * are no side-effects and the call is never performed.
2005 /* Disable trace points before removing it */
2006 tk
= find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM
);
2007 if (WARN_ON_ONCE(tk
== NULL
)) {
2008 pr_warn("error on getting test probe.\n");
2011 if (trace_kprobe_nhit(tk
) != 1) {
2012 pr_warn("incorrect number of testprobe hits\n");
2016 file
= find_trace_probe_file(tk
, top_trace_array());
2017 if (WARN_ON_ONCE(file
== NULL
)) {
2018 pr_warn("error on getting probe file.\n");
2021 disable_trace_kprobe(
2022 trace_probe_event_call(&tk
->tp
), file
);
2025 tk
= find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM
);
2026 if (WARN_ON_ONCE(tk
== NULL
)) {
2027 pr_warn("error on getting 2nd test probe.\n");
2030 if (trace_kprobe_nhit(tk
) != 1) {
2031 pr_warn("incorrect number of testprobe2 hits\n");
2035 file
= find_trace_probe_file(tk
, top_trace_array());
2036 if (WARN_ON_ONCE(file
== NULL
)) {
2037 pr_warn("error on getting probe file.\n");
2040 disable_trace_kprobe(
2041 trace_probe_event_call(&tk
->tp
), file
);
2044 ret
= trace_run_command("-:testprobe", create_or_delete_trace_kprobe
);
2045 if (WARN_ON_ONCE(ret
)) {
2046 pr_warn("error on deleting a probe.\n");
2050 ret
= trace_run_command("-:testprobe2", create_or_delete_trace_kprobe
);
2051 if (WARN_ON_ONCE(ret
)) {
2052 pr_warn("error on deleting a probe.\n");
2057 ret
= dyn_events_release_all(&trace_kprobe_ops
);
2058 if (WARN_ON_ONCE(ret
)) {
2059 pr_warn("error on cleaning up probes.\n");
2063 * Wait for the optimizer work to finish. Otherwise it might fiddle
2064 * with probes in already freed __init text.
2066 wait_for_kprobe_optimizer();
2068 pr_cont("NG: Some tests are failed. Please check them.\n");
2074 late_initcall(kprobe_trace_self_tests_init
);