2 * Kprobes-based tracing events
4 * Created by Masami Hiramatsu <mhiramat@redhat.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include <linux/module.h>
21 #include <linux/uaccess.h>
23 #include "trace_probe.h"
25 #define KPROBE_EVENT_SYSTEM "kprobes"
28 * Kprobe event core functions
31 struct list_head list
;
32 struct kretprobe rp
; /* Use rp.kp for kprobe use */
34 const char *symbol
; /* symbol name */
35 struct trace_probe tp
;
38 #define SIZEOF_TRACE_KPROBE(n) \
39 (offsetof(struct trace_kprobe, tp.args) + \
40 (sizeof(struct probe_arg) * (n)))
43 static __kprobes
bool trace_kprobe_is_return(struct trace_kprobe
*tk
)
45 return tk
->rp
.handler
!= NULL
;
48 static __kprobes
const char *trace_kprobe_symbol(struct trace_kprobe
*tk
)
50 return tk
->symbol
? tk
->symbol
: "unknown";
53 static __kprobes
unsigned long trace_kprobe_offset(struct trace_kprobe
*tk
)
55 return tk
->rp
.kp
.offset
;
58 static __kprobes
bool trace_kprobe_has_gone(struct trace_kprobe
*tk
)
60 return !!(kprobe_gone(&tk
->rp
.kp
));
63 static __kprobes
bool trace_kprobe_within_module(struct trace_kprobe
*tk
,
66 int len
= strlen(mod
->name
);
67 const char *name
= trace_kprobe_symbol(tk
);
68 return strncmp(mod
->name
, name
, len
) == 0 && name
[len
] == ':';
71 static __kprobes
bool trace_kprobe_is_on_module(struct trace_kprobe
*tk
)
73 return !!strchr(trace_kprobe_symbol(tk
), ':');
76 static int register_kprobe_event(struct trace_kprobe
*tk
);
77 static int unregister_kprobe_event(struct trace_kprobe
*tk
);
79 static DEFINE_MUTEX(probe_lock
);
80 static LIST_HEAD(probe_list
);
82 static int kprobe_dispatcher(struct kprobe
*kp
, struct pt_regs
*regs
);
83 static int kretprobe_dispatcher(struct kretprobe_instance
*ri
,
84 struct pt_regs
*regs
);
86 /* Memory fetching by symbol */
93 unsigned long update_symbol_cache(struct symbol_cache
*sc
)
95 sc
->addr
= (unsigned long)kallsyms_lookup_name(sc
->symbol
);
98 sc
->addr
+= sc
->offset
;
103 void free_symbol_cache(struct symbol_cache
*sc
)
109 struct symbol_cache
*alloc_symbol_cache(const char *sym
, long offset
)
111 struct symbol_cache
*sc
;
113 if (!sym
|| strlen(sym
) == 0)
116 sc
= kzalloc(sizeof(struct symbol_cache
), GFP_KERNEL
);
120 sc
->symbol
= kstrdup(sym
, GFP_KERNEL
);
126 update_symbol_cache(sc
);
132 * Kprobes-specific fetch functions
134 #define DEFINE_FETCH_stack(type) \
135 static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
136 void *offset, void *dest) \
138 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
139 (unsigned int)((unsigned long)offset)); \
141 DEFINE_BASIC_FETCH_FUNCS(stack
)
142 /* No string on the stack entry */
143 #define fetch_stack_string NULL
144 #define fetch_stack_string_size NULL
146 #define DEFINE_FETCH_memory(type) \
147 static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
148 void *addr, void *dest) \
151 if (probe_kernel_address(addr, retval)) \
154 *(type *)dest = retval; \
156 DEFINE_BASIC_FETCH_FUNCS(memory
)
158 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
159 * length and relative data location.
161 static __kprobes
void FETCH_FUNC_NAME(memory
, string
)(struct pt_regs
*regs
,
162 void *addr
, void *dest
)
165 int maxlen
= get_rloc_len(*(u32
*)dest
);
166 u8
*dst
= get_rloc_data(dest
);
168 mm_segment_t old_fs
= get_fs();
174 * Try to get string again, since the string can be changed while
181 ret
= __copy_from_user_inatomic(dst
++, src
++, 1);
182 while (dst
[-1] && ret
== 0 && src
- (u8
*)addr
< maxlen
);
188 if (ret
< 0) { /* Failed to fetch string */
189 ((u8
*)get_rloc_data(dest
))[0] = '\0';
190 *(u32
*)dest
= make_data_rloc(0, get_rloc_offs(*(u32
*)dest
));
192 *(u32
*)dest
= make_data_rloc(src
- (u8
*)addr
,
193 get_rloc_offs(*(u32
*)dest
));
197 /* Return the length of string -- including null terminal byte */
198 static __kprobes
void FETCH_FUNC_NAME(memory
, string_size
)(struct pt_regs
*regs
,
199 void *addr
, void *dest
)
210 ret
= __copy_from_user_inatomic(&c
, (u8
*)addr
+ len
, 1);
212 } while (c
&& ret
== 0 && len
< MAX_STRING_SIZE
);
217 if (ret
< 0) /* Failed to check the length */
223 #define DEFINE_FETCH_symbol(type) \
224 __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \
225 void *data, void *dest) \
227 struct symbol_cache *sc = data; \
229 fetch_memory_##type(regs, (void *)sc->addr, dest); \
233 DEFINE_BASIC_FETCH_FUNCS(symbol
)
234 DEFINE_FETCH_symbol(string
)
235 DEFINE_FETCH_symbol(string_size
)
237 /* kprobes don't support file_offset fetch methods */
238 #define fetch_file_offset_u8 NULL
239 #define fetch_file_offset_u16 NULL
240 #define fetch_file_offset_u32 NULL
241 #define fetch_file_offset_u64 NULL
242 #define fetch_file_offset_string NULL
243 #define fetch_file_offset_string_size NULL
245 /* Fetch type information table */
246 const struct fetch_type kprobes_fetch_type_table
[] = {
248 [FETCH_TYPE_STRING
] = __ASSIGN_FETCH_TYPE("string", string
, string
,
249 sizeof(u32
), 1, "__data_loc char[]"),
250 [FETCH_TYPE_STRSIZE
] = __ASSIGN_FETCH_TYPE("string_size", u32
,
251 string_size
, sizeof(u32
), 0, "u32"),
253 ASSIGN_FETCH_TYPE(u8
, u8
, 0),
254 ASSIGN_FETCH_TYPE(u16
, u16
, 0),
255 ASSIGN_FETCH_TYPE(u32
, u32
, 0),
256 ASSIGN_FETCH_TYPE(u64
, u64
, 0),
257 ASSIGN_FETCH_TYPE(s8
, u8
, 1),
258 ASSIGN_FETCH_TYPE(s16
, u16
, 1),
259 ASSIGN_FETCH_TYPE(s32
, u32
, 1),
260 ASSIGN_FETCH_TYPE(s64
, u64
, 1),
262 ASSIGN_FETCH_TYPE_END
266 * Allocate new trace_probe and initialize it (including kprobes).
268 static struct trace_kprobe
*alloc_trace_kprobe(const char *group
,
273 int nargs
, bool is_return
)
275 struct trace_kprobe
*tk
;
278 tk
= kzalloc(SIZEOF_TRACE_KPROBE(nargs
), GFP_KERNEL
);
283 tk
->symbol
= kstrdup(symbol
, GFP_KERNEL
);
286 tk
->rp
.kp
.symbol_name
= tk
->symbol
;
287 tk
->rp
.kp
.offset
= offs
;
289 tk
->rp
.kp
.addr
= addr
;
292 tk
->rp
.handler
= kretprobe_dispatcher
;
294 tk
->rp
.kp
.pre_handler
= kprobe_dispatcher
;
296 if (!event
|| !is_good_name(event
)) {
301 tk
->tp
.call
.class = &tk
->tp
.class;
302 tk
->tp
.call
.name
= kstrdup(event
, GFP_KERNEL
);
303 if (!tk
->tp
.call
.name
)
306 if (!group
|| !is_good_name(group
)) {
311 tk
->tp
.class.system
= kstrdup(group
, GFP_KERNEL
);
312 if (!tk
->tp
.class.system
)
315 INIT_LIST_HEAD(&tk
->list
);
316 INIT_LIST_HEAD(&tk
->tp
.files
);
319 kfree(tk
->tp
.call
.name
);
325 static void free_trace_kprobe(struct trace_kprobe
*tk
)
329 for (i
= 0; i
< tk
->tp
.nr_args
; i
++)
330 traceprobe_free_probe_arg(&tk
->tp
.args
[i
]);
332 kfree(tk
->tp
.call
.class->system
);
333 kfree(tk
->tp
.call
.name
);
338 static struct trace_kprobe
*find_trace_kprobe(const char *event
,
341 struct trace_kprobe
*tk
;
343 list_for_each_entry(tk
, &probe_list
, list
)
344 if (strcmp(ftrace_event_name(&tk
->tp
.call
), event
) == 0 &&
345 strcmp(tk
->tp
.call
.class->system
, group
) == 0)
352 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
355 enable_trace_kprobe(struct trace_kprobe
*tk
, struct ftrace_event_file
*file
)
360 struct event_file_link
*link
;
362 link
= kmalloc(sizeof(*link
), GFP_KERNEL
);
369 list_add_tail_rcu(&link
->list
, &tk
->tp
.files
);
371 tk
->tp
.flags
|= TP_FLAG_TRACE
;
373 tk
->tp
.flags
|= TP_FLAG_PROFILE
;
375 if (trace_probe_is_registered(&tk
->tp
) && !trace_kprobe_has_gone(tk
)) {
376 if (trace_kprobe_is_return(tk
))
377 ret
= enable_kretprobe(&tk
->rp
);
379 ret
= enable_kprobe(&tk
->rp
.kp
);
386 * Disable trace_probe
387 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
390 disable_trace_kprobe(struct trace_kprobe
*tk
, struct ftrace_event_file
*file
)
392 struct event_file_link
*link
= NULL
;
397 link
= find_event_file_link(&tk
->tp
, file
);
403 list_del_rcu(&link
->list
);
405 if (!list_empty(&tk
->tp
.files
))
408 tk
->tp
.flags
&= ~TP_FLAG_TRACE
;
410 tk
->tp
.flags
&= ~TP_FLAG_PROFILE
;
412 if (!trace_probe_is_enabled(&tk
->tp
) && trace_probe_is_registered(&tk
->tp
)) {
413 if (trace_kprobe_is_return(tk
))
414 disable_kretprobe(&tk
->rp
);
416 disable_kprobe(&tk
->rp
.kp
);
422 * Synchronize with kprobe_trace_func/kretprobe_trace_func
423 * to ensure disabled (all running handlers are finished).
424 * This is not only for kfree(), but also the caller,
425 * trace_remove_event_call() supposes it for releasing
426 * event_call related objects, which will be accessed in
427 * the kprobe_trace_func/kretprobe_trace_func.
430 kfree(link
); /* Ignored if link == NULL */
436 /* Internal register function - just handle k*probes and flags */
437 static int __register_trace_kprobe(struct trace_kprobe
*tk
)
441 if (trace_probe_is_registered(&tk
->tp
))
444 for (i
= 0; i
< tk
->tp
.nr_args
; i
++)
445 traceprobe_update_arg(&tk
->tp
.args
[i
]);
447 /* Set/clear disabled flag according to tp->flag */
448 if (trace_probe_is_enabled(&tk
->tp
))
449 tk
->rp
.kp
.flags
&= ~KPROBE_FLAG_DISABLED
;
451 tk
->rp
.kp
.flags
|= KPROBE_FLAG_DISABLED
;
453 if (trace_kprobe_is_return(tk
))
454 ret
= register_kretprobe(&tk
->rp
);
456 ret
= register_kprobe(&tk
->rp
.kp
);
459 tk
->tp
.flags
|= TP_FLAG_REGISTERED
;
461 pr_warning("Could not insert probe at %s+%lu: %d\n",
462 trace_kprobe_symbol(tk
), trace_kprobe_offset(tk
), ret
);
463 if (ret
== -ENOENT
&& trace_kprobe_is_on_module(tk
)) {
464 pr_warning("This probe might be able to register after"
465 "target module is loaded. Continue.\n");
467 } else if (ret
== -EILSEQ
) {
468 pr_warning("Probing address(0x%p) is not an "
469 "instruction boundary.\n",
478 /* Internal unregister function - just handle k*probes and flags */
479 static void __unregister_trace_kprobe(struct trace_kprobe
*tk
)
481 if (trace_probe_is_registered(&tk
->tp
)) {
482 if (trace_kprobe_is_return(tk
))
483 unregister_kretprobe(&tk
->rp
);
485 unregister_kprobe(&tk
->rp
.kp
);
486 tk
->tp
.flags
&= ~TP_FLAG_REGISTERED
;
487 /* Cleanup kprobe for reuse */
488 if (tk
->rp
.kp
.symbol_name
)
489 tk
->rp
.kp
.addr
= NULL
;
493 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
494 static int unregister_trace_kprobe(struct trace_kprobe
*tk
)
496 /* Enabled event can not be unregistered */
497 if (trace_probe_is_enabled(&tk
->tp
))
500 /* Will fail if probe is being used by ftrace or perf */
501 if (unregister_kprobe_event(tk
))
504 __unregister_trace_kprobe(tk
);
510 /* Register a trace_probe and probe_event */
511 static int register_trace_kprobe(struct trace_kprobe
*tk
)
513 struct trace_kprobe
*old_tk
;
516 mutex_lock(&probe_lock
);
518 /* Delete old (same name) event if exist */
519 old_tk
= find_trace_kprobe(ftrace_event_name(&tk
->tp
.call
),
520 tk
->tp
.call
.class->system
);
522 ret
= unregister_trace_kprobe(old_tk
);
525 free_trace_kprobe(old_tk
);
528 /* Register new event */
529 ret
= register_kprobe_event(tk
);
531 pr_warning("Failed to register probe event(%d)\n", ret
);
535 /* Register k*probe */
536 ret
= __register_trace_kprobe(tk
);
538 unregister_kprobe_event(tk
);
540 list_add_tail(&tk
->list
, &probe_list
);
543 mutex_unlock(&probe_lock
);
547 /* Module notifier call back, checking event on the module */
548 static int trace_kprobe_module_callback(struct notifier_block
*nb
,
549 unsigned long val
, void *data
)
551 struct module
*mod
= data
;
552 struct trace_kprobe
*tk
;
555 if (val
!= MODULE_STATE_COMING
)
558 /* Update probes on coming module */
559 mutex_lock(&probe_lock
);
560 list_for_each_entry(tk
, &probe_list
, list
) {
561 if (trace_kprobe_within_module(tk
, mod
)) {
562 /* Don't need to check busy - this should have gone. */
563 __unregister_trace_kprobe(tk
);
564 ret
= __register_trace_kprobe(tk
);
566 pr_warning("Failed to re-register probe %s on"
568 ftrace_event_name(&tk
->tp
.call
),
572 mutex_unlock(&probe_lock
);
577 static struct notifier_block trace_kprobe_module_nb
= {
578 .notifier_call
= trace_kprobe_module_callback
,
579 .priority
= 1 /* Invoked after kprobe module callback */
582 static int create_trace_kprobe(int argc
, char **argv
)
586 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
587 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
589 * $retval : fetch return value
590 * $stack : fetch stack address
591 * $stackN : fetch Nth of stack (N:0-)
592 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
593 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
594 * %REG : fetch register REG
595 * Dereferencing memory fetch:
596 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
597 * Alias name of args:
598 * NAME=FETCHARG : set NAME as alias of FETCHARG.
600 * FETCHARG:TYPE : use TYPE instead of unsigned long.
602 struct trace_kprobe
*tk
;
604 bool is_return
= false, is_delete
= false;
605 char *symbol
= NULL
, *event
= NULL
, *group
= NULL
;
607 unsigned long offset
= 0;
609 char buf
[MAX_EVENT_NAME_LEN
];
611 /* argc must be >= 1 */
612 if (argv
[0][0] == 'p')
614 else if (argv
[0][0] == 'r')
616 else if (argv
[0][0] == '-')
619 pr_info("Probe definition must be started with 'p', 'r' or"
624 if (argv
[0][1] == ':') {
626 if (strchr(event
, '/')) {
628 event
= strchr(group
, '/') + 1;
630 if (strlen(group
) == 0) {
631 pr_info("Group name is not specified\n");
635 if (strlen(event
) == 0) {
636 pr_info("Event name is not specified\n");
641 group
= KPROBE_EVENT_SYSTEM
;
645 pr_info("Delete command needs an event name.\n");
648 mutex_lock(&probe_lock
);
649 tk
= find_trace_kprobe(event
, group
);
651 mutex_unlock(&probe_lock
);
652 pr_info("Event %s/%s doesn't exist.\n", group
, event
);
655 /* delete an event */
656 ret
= unregister_trace_kprobe(tk
);
658 free_trace_kprobe(tk
);
659 mutex_unlock(&probe_lock
);
664 pr_info("Probe point is not specified.\n");
667 if (isdigit(argv
[1][0])) {
669 pr_info("Return probe point must be a symbol.\n");
672 /* an address specified */
673 ret
= kstrtoul(&argv
[1][0], 0, (unsigned long *)&addr
);
675 pr_info("Failed to parse address.\n");
679 /* a symbol specified */
681 /* TODO: support .init module functions */
682 ret
= traceprobe_split_symbol_offset(symbol
, &offset
);
684 pr_info("Failed to parse symbol.\n");
687 if (offset
&& is_return
) {
688 pr_info("Return probe must be used without offset.\n");
692 argc
-= 2; argv
+= 2;
696 /* Make a new event name */
698 snprintf(buf
, MAX_EVENT_NAME_LEN
, "%c_%s_%ld",
699 is_return
? 'r' : 'p', symbol
, offset
);
701 snprintf(buf
, MAX_EVENT_NAME_LEN
, "%c_0x%p",
702 is_return
? 'r' : 'p', addr
);
705 tk
= alloc_trace_kprobe(group
, event
, addr
, symbol
, offset
, argc
,
708 pr_info("Failed to allocate trace_probe.(%d)\n",
713 /* parse arguments */
715 for (i
= 0; i
< argc
&& i
< MAX_TRACE_ARGS
; i
++) {
716 struct probe_arg
*parg
= &tk
->tp
.args
[i
];
718 /* Increment count for freeing args in error case */
721 /* Parse argument name */
722 arg
= strchr(argv
[i
], '=');
725 parg
->name
= kstrdup(argv
[i
], GFP_KERNEL
);
728 /* If argument name is omitted, set "argN" */
729 snprintf(buf
, MAX_EVENT_NAME_LEN
, "arg%d", i
+ 1);
730 parg
->name
= kstrdup(buf
, GFP_KERNEL
);
734 pr_info("Failed to allocate argument[%d] name.\n", i
);
739 if (!is_good_name(parg
->name
)) {
740 pr_info("Invalid argument[%d] name: %s\n",
746 if (traceprobe_conflict_field_name(parg
->name
,
748 pr_info("Argument[%d] name '%s' conflicts with "
749 "another field.\n", i
, argv
[i
]);
754 /* Parse fetch argument */
755 ret
= traceprobe_parse_probe_arg(arg
, &tk
->tp
.size
, parg
,
758 pr_info("Parse error at argument[%d]. (%d)\n", i
, ret
);
763 ret
= register_trace_kprobe(tk
);
769 free_trace_kprobe(tk
);
773 static int release_all_trace_kprobes(void)
775 struct trace_kprobe
*tk
;
778 mutex_lock(&probe_lock
);
779 /* Ensure no probe is in use. */
780 list_for_each_entry(tk
, &probe_list
, list
)
781 if (trace_probe_is_enabled(&tk
->tp
)) {
785 /* TODO: Use batch unregistration */
786 while (!list_empty(&probe_list
)) {
787 tk
= list_entry(probe_list
.next
, struct trace_kprobe
, list
);
788 ret
= unregister_trace_kprobe(tk
);
791 free_trace_kprobe(tk
);
795 mutex_unlock(&probe_lock
);
800 /* Probes listing interfaces */
801 static void *probes_seq_start(struct seq_file
*m
, loff_t
*pos
)
803 mutex_lock(&probe_lock
);
804 return seq_list_start(&probe_list
, *pos
);
807 static void *probes_seq_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
809 return seq_list_next(v
, &probe_list
, pos
);
812 static void probes_seq_stop(struct seq_file
*m
, void *v
)
814 mutex_unlock(&probe_lock
);
817 static int probes_seq_show(struct seq_file
*m
, void *v
)
819 struct trace_kprobe
*tk
= v
;
822 seq_printf(m
, "%c", trace_kprobe_is_return(tk
) ? 'r' : 'p');
823 seq_printf(m
, ":%s/%s", tk
->tp
.call
.class->system
,
824 ftrace_event_name(&tk
->tp
.call
));
827 seq_printf(m
, " 0x%p", tk
->rp
.kp
.addr
);
828 else if (tk
->rp
.kp
.offset
)
829 seq_printf(m
, " %s+%u", trace_kprobe_symbol(tk
),
832 seq_printf(m
, " %s", trace_kprobe_symbol(tk
));
834 for (i
= 0; i
< tk
->tp
.nr_args
; i
++)
835 seq_printf(m
, " %s=%s", tk
->tp
.args
[i
].name
, tk
->tp
.args
[i
].comm
);
841 static const struct seq_operations probes_seq_op
= {
842 .start
= probes_seq_start
,
843 .next
= probes_seq_next
,
844 .stop
= probes_seq_stop
,
845 .show
= probes_seq_show
848 static int probes_open(struct inode
*inode
, struct file
*file
)
852 if ((file
->f_mode
& FMODE_WRITE
) && (file
->f_flags
& O_TRUNC
)) {
853 ret
= release_all_trace_kprobes();
858 return seq_open(file
, &probes_seq_op
);
861 static ssize_t
probes_write(struct file
*file
, const char __user
*buffer
,
862 size_t count
, loff_t
*ppos
)
864 return traceprobe_probes_write(file
, buffer
, count
, ppos
,
865 create_trace_kprobe
);
868 static const struct file_operations kprobe_events_ops
= {
869 .owner
= THIS_MODULE
,
873 .release
= seq_release
,
874 .write
= probes_write
,
877 /* Probes profiling interfaces */
878 static int probes_profile_seq_show(struct seq_file
*m
, void *v
)
880 struct trace_kprobe
*tk
= v
;
882 seq_printf(m
, " %-44s %15lu %15lu\n",
883 ftrace_event_name(&tk
->tp
.call
), tk
->nhit
,
889 static const struct seq_operations profile_seq_op
= {
890 .start
= probes_seq_start
,
891 .next
= probes_seq_next
,
892 .stop
= probes_seq_stop
,
893 .show
= probes_profile_seq_show
896 static int profile_open(struct inode
*inode
, struct file
*file
)
898 return seq_open(file
, &profile_seq_op
);
901 static const struct file_operations kprobe_profile_ops
= {
902 .owner
= THIS_MODULE
,
903 .open
= profile_open
,
906 .release
= seq_release
,
910 static __kprobes
void
911 __kprobe_trace_func(struct trace_kprobe
*tk
, struct pt_regs
*regs
,
912 struct ftrace_event_file
*ftrace_file
)
914 struct kprobe_trace_entry_head
*entry
;
915 struct ring_buffer_event
*event
;
916 struct ring_buffer
*buffer
;
918 unsigned long irq_flags
;
919 struct ftrace_event_call
*call
= &tk
->tp
.call
;
921 WARN_ON(call
!= ftrace_file
->event_call
);
923 if (ftrace_trigger_soft_disabled(ftrace_file
))
926 local_save_flags(irq_flags
);
927 pc
= preempt_count();
929 dsize
= __get_data_size(&tk
->tp
, regs
);
930 size
= sizeof(*entry
) + tk
->tp
.size
+ dsize
;
932 event
= trace_event_buffer_lock_reserve(&buffer
, ftrace_file
,
934 size
, irq_flags
, pc
);
938 entry
= ring_buffer_event_data(event
);
939 entry
->ip
= (unsigned long)tk
->rp
.kp
.addr
;
940 store_trace_args(sizeof(*entry
), &tk
->tp
, regs
, (u8
*)&entry
[1], dsize
);
942 event_trigger_unlock_commit_regs(ftrace_file
, buffer
, event
,
943 entry
, irq_flags
, pc
, regs
);
946 static __kprobes
void
947 kprobe_trace_func(struct trace_kprobe
*tk
, struct pt_regs
*regs
)
949 struct event_file_link
*link
;
951 list_for_each_entry_rcu(link
, &tk
->tp
.files
, list
)
952 __kprobe_trace_func(tk
, regs
, link
->file
);
955 /* Kretprobe handler */
956 static __kprobes
void
957 __kretprobe_trace_func(struct trace_kprobe
*tk
, struct kretprobe_instance
*ri
,
958 struct pt_regs
*regs
,
959 struct ftrace_event_file
*ftrace_file
)
961 struct kretprobe_trace_entry_head
*entry
;
962 struct ring_buffer_event
*event
;
963 struct ring_buffer
*buffer
;
965 unsigned long irq_flags
;
966 struct ftrace_event_call
*call
= &tk
->tp
.call
;
968 WARN_ON(call
!= ftrace_file
->event_call
);
970 if (ftrace_trigger_soft_disabled(ftrace_file
))
973 local_save_flags(irq_flags
);
974 pc
= preempt_count();
976 dsize
= __get_data_size(&tk
->tp
, regs
);
977 size
= sizeof(*entry
) + tk
->tp
.size
+ dsize
;
979 event
= trace_event_buffer_lock_reserve(&buffer
, ftrace_file
,
981 size
, irq_flags
, pc
);
985 entry
= ring_buffer_event_data(event
);
986 entry
->func
= (unsigned long)tk
->rp
.kp
.addr
;
987 entry
->ret_ip
= (unsigned long)ri
->ret_addr
;
988 store_trace_args(sizeof(*entry
), &tk
->tp
, regs
, (u8
*)&entry
[1], dsize
);
990 event_trigger_unlock_commit_regs(ftrace_file
, buffer
, event
,
991 entry
, irq_flags
, pc
, regs
);
994 static __kprobes
void
995 kretprobe_trace_func(struct trace_kprobe
*tk
, struct kretprobe_instance
*ri
,
996 struct pt_regs
*regs
)
998 struct event_file_link
*link
;
1000 list_for_each_entry_rcu(link
, &tk
->tp
.files
, list
)
1001 __kretprobe_trace_func(tk
, ri
, regs
, link
->file
);
1004 /* Event entry printers */
1005 static enum print_line_t
1006 print_kprobe_event(struct trace_iterator
*iter
, int flags
,
1007 struct trace_event
*event
)
1009 struct kprobe_trace_entry_head
*field
;
1010 struct trace_seq
*s
= &iter
->seq
;
1011 struct trace_probe
*tp
;
1015 field
= (struct kprobe_trace_entry_head
*)iter
->ent
;
1016 tp
= container_of(event
, struct trace_probe
, call
.event
);
1018 if (!trace_seq_printf(s
, "%s: (", ftrace_event_name(&tp
->call
)))
1021 if (!seq_print_ip_sym(s
, field
->ip
, flags
| TRACE_ITER_SYM_OFFSET
))
1024 if (!trace_seq_puts(s
, ")"))
1027 data
= (u8
*)&field
[1];
1028 for (i
= 0; i
< tp
->nr_args
; i
++)
1029 if (!tp
->args
[i
].type
->print(s
, tp
->args
[i
].name
,
1030 data
+ tp
->args
[i
].offset
, field
))
1033 if (!trace_seq_puts(s
, "\n"))
1036 return TRACE_TYPE_HANDLED
;
1038 return TRACE_TYPE_PARTIAL_LINE
;
1041 static enum print_line_t
1042 print_kretprobe_event(struct trace_iterator
*iter
, int flags
,
1043 struct trace_event
*event
)
1045 struct kretprobe_trace_entry_head
*field
;
1046 struct trace_seq
*s
= &iter
->seq
;
1047 struct trace_probe
*tp
;
1051 field
= (struct kretprobe_trace_entry_head
*)iter
->ent
;
1052 tp
= container_of(event
, struct trace_probe
, call
.event
);
1054 if (!trace_seq_printf(s
, "%s: (", ftrace_event_name(&tp
->call
)))
1057 if (!seq_print_ip_sym(s
, field
->ret_ip
, flags
| TRACE_ITER_SYM_OFFSET
))
1060 if (!trace_seq_puts(s
, " <- "))
1063 if (!seq_print_ip_sym(s
, field
->func
, flags
& ~TRACE_ITER_SYM_OFFSET
))
1066 if (!trace_seq_puts(s
, ")"))
1069 data
= (u8
*)&field
[1];
1070 for (i
= 0; i
< tp
->nr_args
; i
++)
1071 if (!tp
->args
[i
].type
->print(s
, tp
->args
[i
].name
,
1072 data
+ tp
->args
[i
].offset
, field
))
1075 if (!trace_seq_puts(s
, "\n"))
1078 return TRACE_TYPE_HANDLED
;
1080 return TRACE_TYPE_PARTIAL_LINE
;
1084 static int kprobe_event_define_fields(struct ftrace_event_call
*event_call
)
1087 struct kprobe_trace_entry_head field
;
1088 struct trace_kprobe
*tk
= (struct trace_kprobe
*)event_call
->data
;
1090 DEFINE_FIELD(unsigned long, ip
, FIELD_STRING_IP
, 0);
1091 /* Set argument names as fields */
1092 for (i
= 0; i
< tk
->tp
.nr_args
; i
++) {
1093 struct probe_arg
*parg
= &tk
->tp
.args
[i
];
1095 ret
= trace_define_field(event_call
, parg
->type
->fmttype
,
1097 sizeof(field
) + parg
->offset
,
1099 parg
->type
->is_signed
,
1107 static int kretprobe_event_define_fields(struct ftrace_event_call
*event_call
)
1110 struct kretprobe_trace_entry_head field
;
1111 struct trace_kprobe
*tk
= (struct trace_kprobe
*)event_call
->data
;
1113 DEFINE_FIELD(unsigned long, func
, FIELD_STRING_FUNC
, 0);
1114 DEFINE_FIELD(unsigned long, ret_ip
, FIELD_STRING_RETIP
, 0);
1115 /* Set argument names as fields */
1116 for (i
= 0; i
< tk
->tp
.nr_args
; i
++) {
1117 struct probe_arg
*parg
= &tk
->tp
.args
[i
];
1119 ret
= trace_define_field(event_call
, parg
->type
->fmttype
,
1121 sizeof(field
) + parg
->offset
,
1123 parg
->type
->is_signed
,
1131 #ifdef CONFIG_PERF_EVENTS
1133 /* Kprobe profile handler */
1134 static __kprobes
void
1135 kprobe_perf_func(struct trace_kprobe
*tk
, struct pt_regs
*regs
)
1137 struct ftrace_event_call
*call
= &tk
->tp
.call
;
1138 struct kprobe_trace_entry_head
*entry
;
1139 struct hlist_head
*head
;
1140 int size
, __size
, dsize
;
1143 head
= this_cpu_ptr(call
->perf_events
);
1144 if (hlist_empty(head
))
1147 dsize
= __get_data_size(&tk
->tp
, regs
);
1148 __size
= sizeof(*entry
) + tk
->tp
.size
+ dsize
;
1149 size
= ALIGN(__size
+ sizeof(u32
), sizeof(u64
));
1150 size
-= sizeof(u32
);
1152 entry
= perf_trace_buf_prepare(size
, call
->event
.type
, regs
, &rctx
);
1156 entry
->ip
= (unsigned long)tk
->rp
.kp
.addr
;
1157 memset(&entry
[1], 0, dsize
);
1158 store_trace_args(sizeof(*entry
), &tk
->tp
, regs
, (u8
*)&entry
[1], dsize
);
1159 perf_trace_buf_submit(entry
, size
, rctx
, 0, 1, regs
, head
, NULL
);
1162 /* Kretprobe profile handler */
1163 static __kprobes
void
1164 kretprobe_perf_func(struct trace_kprobe
*tk
, struct kretprobe_instance
*ri
,
1165 struct pt_regs
*regs
)
1167 struct ftrace_event_call
*call
= &tk
->tp
.call
;
1168 struct kretprobe_trace_entry_head
*entry
;
1169 struct hlist_head
*head
;
1170 int size
, __size
, dsize
;
1173 head
= this_cpu_ptr(call
->perf_events
);
1174 if (hlist_empty(head
))
1177 dsize
= __get_data_size(&tk
->tp
, regs
);
1178 __size
= sizeof(*entry
) + tk
->tp
.size
+ dsize
;
1179 size
= ALIGN(__size
+ sizeof(u32
), sizeof(u64
));
1180 size
-= sizeof(u32
);
1182 entry
= perf_trace_buf_prepare(size
, call
->event
.type
, regs
, &rctx
);
1186 entry
->func
= (unsigned long)tk
->rp
.kp
.addr
;
1187 entry
->ret_ip
= (unsigned long)ri
->ret_addr
;
1188 store_trace_args(sizeof(*entry
), &tk
->tp
, regs
, (u8
*)&entry
[1], dsize
);
1189 perf_trace_buf_submit(entry
, size
, rctx
, 0, 1, regs
, head
, NULL
);
1191 #endif /* CONFIG_PERF_EVENTS */
1194 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1196 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1197 * lockless, but we can't race with this __init function.
1200 int kprobe_register(struct ftrace_event_call
*event
,
1201 enum trace_reg type
, void *data
)
1203 struct trace_kprobe
*tk
= (struct trace_kprobe
*)event
->data
;
1204 struct ftrace_event_file
*file
= data
;
1207 case TRACE_REG_REGISTER
:
1208 return enable_trace_kprobe(tk
, file
);
1209 case TRACE_REG_UNREGISTER
:
1210 return disable_trace_kprobe(tk
, file
);
1212 #ifdef CONFIG_PERF_EVENTS
1213 case TRACE_REG_PERF_REGISTER
:
1214 return enable_trace_kprobe(tk
, NULL
);
1215 case TRACE_REG_PERF_UNREGISTER
:
1216 return disable_trace_kprobe(tk
, NULL
);
1217 case TRACE_REG_PERF_OPEN
:
1218 case TRACE_REG_PERF_CLOSE
:
1219 case TRACE_REG_PERF_ADD
:
1220 case TRACE_REG_PERF_DEL
:
1228 int kprobe_dispatcher(struct kprobe
*kp
, struct pt_regs
*regs
)
1230 struct trace_kprobe
*tk
= container_of(kp
, struct trace_kprobe
, rp
.kp
);
1234 if (tk
->tp
.flags
& TP_FLAG_TRACE
)
1235 kprobe_trace_func(tk
, regs
);
1236 #ifdef CONFIG_PERF_EVENTS
1237 if (tk
->tp
.flags
& TP_FLAG_PROFILE
)
1238 kprobe_perf_func(tk
, regs
);
1240 return 0; /* We don't tweek kernel, so just return 0 */
1244 int kretprobe_dispatcher(struct kretprobe_instance
*ri
, struct pt_regs
*regs
)
1246 struct trace_kprobe
*tk
= container_of(ri
->rp
, struct trace_kprobe
, rp
);
1250 if (tk
->tp
.flags
& TP_FLAG_TRACE
)
1251 kretprobe_trace_func(tk
, ri
, regs
);
1252 #ifdef CONFIG_PERF_EVENTS
1253 if (tk
->tp
.flags
& TP_FLAG_PROFILE
)
1254 kretprobe_perf_func(tk
, ri
, regs
);
1256 return 0; /* We don't tweek kernel, so just return 0 */
1259 static struct trace_event_functions kretprobe_funcs
= {
1260 .trace
= print_kretprobe_event
1263 static struct trace_event_functions kprobe_funcs
= {
1264 .trace
= print_kprobe_event
1267 static int register_kprobe_event(struct trace_kprobe
*tk
)
1269 struct ftrace_event_call
*call
= &tk
->tp
.call
;
1272 /* Initialize ftrace_event_call */
1273 INIT_LIST_HEAD(&call
->class->fields
);
1274 if (trace_kprobe_is_return(tk
)) {
1275 call
->event
.funcs
= &kretprobe_funcs
;
1276 call
->class->define_fields
= kretprobe_event_define_fields
;
1278 call
->event
.funcs
= &kprobe_funcs
;
1279 call
->class->define_fields
= kprobe_event_define_fields
;
1281 if (set_print_fmt(&tk
->tp
, trace_kprobe_is_return(tk
)) < 0)
1283 ret
= register_ftrace_event(&call
->event
);
1285 kfree(call
->print_fmt
);
1289 call
->class->reg
= kprobe_register
;
1291 ret
= trace_add_event_call(call
);
1293 pr_info("Failed to register kprobe event: %s\n",
1294 ftrace_event_name(call
));
1295 kfree(call
->print_fmt
);
1296 unregister_ftrace_event(&call
->event
);
1301 static int unregister_kprobe_event(struct trace_kprobe
*tk
)
1305 /* tp->event is unregistered in trace_remove_event_call() */
1306 ret
= trace_remove_event_call(&tk
->tp
.call
);
1308 kfree(tk
->tp
.call
.print_fmt
);
1312 /* Make a debugfs interface for controlling probe points */
1313 static __init
int init_kprobe_trace(void)
1315 struct dentry
*d_tracer
;
1316 struct dentry
*entry
;
1318 if (register_module_notifier(&trace_kprobe_module_nb
))
1321 d_tracer
= tracing_init_dentry();
1325 entry
= debugfs_create_file("kprobe_events", 0644, d_tracer
,
1326 NULL
, &kprobe_events_ops
);
1328 /* Event list interface */
1330 pr_warning("Could not create debugfs "
1331 "'kprobe_events' entry\n");
1333 /* Profile interface */
1334 entry
= debugfs_create_file("kprobe_profile", 0444, d_tracer
,
1335 NULL
, &kprobe_profile_ops
);
1338 pr_warning("Could not create debugfs "
1339 "'kprobe_profile' entry\n");
1342 fs_initcall(init_kprobe_trace
);
1345 #ifdef CONFIG_FTRACE_STARTUP_TEST
1348 * The "__used" keeps gcc from removing the function symbol
1349 * from the kallsyms table.
1351 static __used
int kprobe_trace_selftest_target(int a1
, int a2
, int a3
,
1352 int a4
, int a5
, int a6
)
1354 return a1
+ a2
+ a3
+ a4
+ a5
+ a6
;
1357 static struct ftrace_event_file
*
1358 find_trace_probe_file(struct trace_kprobe
*tk
, struct trace_array
*tr
)
1360 struct ftrace_event_file
*file
;
1362 list_for_each_entry(file
, &tr
->events
, list
)
1363 if (file
->event_call
== &tk
->tp
.call
)
1370 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1371 * stage, we can do this lockless.
1373 static __init
int kprobe_trace_self_tests_init(void)
1376 int (*target
)(int, int, int, int, int, int);
1377 struct trace_kprobe
*tk
;
1378 struct ftrace_event_file
*file
;
1380 target
= kprobe_trace_selftest_target
;
1382 pr_info("Testing kprobe tracing: ");
1384 ret
= traceprobe_command("p:testprobe kprobe_trace_selftest_target "
1385 "$stack $stack0 +0($stack)",
1386 create_trace_kprobe
);
1387 if (WARN_ON_ONCE(ret
)) {
1388 pr_warn("error on probing function entry.\n");
1391 /* Enable trace point */
1392 tk
= find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM
);
1393 if (WARN_ON_ONCE(tk
== NULL
)) {
1394 pr_warn("error on getting new probe.\n");
1397 file
= find_trace_probe_file(tk
, top_trace_array());
1398 if (WARN_ON_ONCE(file
== NULL
)) {
1399 pr_warn("error on getting probe file.\n");
1402 enable_trace_kprobe(tk
, file
);
1406 ret
= traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
1407 "$retval", create_trace_kprobe
);
1408 if (WARN_ON_ONCE(ret
)) {
1409 pr_warn("error on probing function return.\n");
1412 /* Enable trace point */
1413 tk
= find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM
);
1414 if (WARN_ON_ONCE(tk
== NULL
)) {
1415 pr_warn("error on getting 2nd new probe.\n");
1418 file
= find_trace_probe_file(tk
, top_trace_array());
1419 if (WARN_ON_ONCE(file
== NULL
)) {
1420 pr_warn("error on getting probe file.\n");
1423 enable_trace_kprobe(tk
, file
);
1430 ret
= target(1, 2, 3, 4, 5, 6);
1432 /* Disable trace points before removing it */
1433 tk
= find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM
);
1434 if (WARN_ON_ONCE(tk
== NULL
)) {
1435 pr_warn("error on getting test probe.\n");
1438 file
= find_trace_probe_file(tk
, top_trace_array());
1439 if (WARN_ON_ONCE(file
== NULL
)) {
1440 pr_warn("error on getting probe file.\n");
1443 disable_trace_kprobe(tk
, file
);
1446 tk
= find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM
);
1447 if (WARN_ON_ONCE(tk
== NULL
)) {
1448 pr_warn("error on getting 2nd test probe.\n");
1451 file
= find_trace_probe_file(tk
, top_trace_array());
1452 if (WARN_ON_ONCE(file
== NULL
)) {
1453 pr_warn("error on getting probe file.\n");
1456 disable_trace_kprobe(tk
, file
);
1459 ret
= traceprobe_command("-:testprobe", create_trace_kprobe
);
1460 if (WARN_ON_ONCE(ret
)) {
1461 pr_warn("error on deleting a probe.\n");
1465 ret
= traceprobe_command("-:testprobe2", create_trace_kprobe
);
1466 if (WARN_ON_ONCE(ret
)) {
1467 pr_warn("error on deleting a probe.\n");
1472 release_all_trace_kprobes();
1474 pr_cont("NG: Some tests are failed. Please check them.\n");
1480 late_initcall(kprobe_trace_self_tests_init
);