1 // SPDX-License-Identifier: GPL-2.0
3 * uprobes-based tracing events
5 * Copyright (C) IBM Corporation, 2010-2012
6 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
8 #define pr_fmt(fmt) "trace_uprobe: " fmt
10 #include <linux/ctype.h>
11 #include <linux/module.h>
12 #include <linux/uaccess.h>
13 #include <linux/uprobes.h>
14 #include <linux/namei.h>
15 #include <linux/string.h>
16 #include <linux/rculist.h>
18 #include "trace_dynevent.h"
19 #include "trace_probe.h"
20 #include "trace_probe_tmpl.h"
22 #define UPROBE_EVENT_SYSTEM "uprobes"
24 struct uprobe_trace_entry_head
{
25 struct trace_entry ent
;
26 unsigned long vaddr
[];
29 #define SIZEOF_TRACE_ENTRY(is_return) \
30 (sizeof(struct uprobe_trace_entry_head) + \
31 sizeof(unsigned long) * (is_return ? 2 : 1))
33 #define DATAOF_TRACE_ENTRY(entry, is_return) \
34 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
36 struct trace_uprobe_filter
{
39 struct list_head perf_events
;
42 static int trace_uprobe_create(int argc
, const char **argv
);
43 static int trace_uprobe_show(struct seq_file
*m
, struct dyn_event
*ev
);
44 static int trace_uprobe_release(struct dyn_event
*ev
);
45 static bool trace_uprobe_is_busy(struct dyn_event
*ev
);
46 static bool trace_uprobe_match(const char *system
, const char *event
,
47 struct dyn_event
*ev
);
49 static struct dyn_event_operations trace_uprobe_ops
= {
50 .create
= trace_uprobe_create
,
51 .show
= trace_uprobe_show
,
52 .is_busy
= trace_uprobe_is_busy
,
53 .free
= trace_uprobe_release
,
54 .match
= trace_uprobe_match
,
58 * uprobe event core functions
61 struct dyn_event devent
;
62 struct trace_uprobe_filter filter
;
63 struct uprobe_consumer consumer
;
68 unsigned long ref_ctr_offset
;
70 struct trace_probe tp
;
73 static bool is_trace_uprobe(struct dyn_event
*ev
)
75 return ev
->ops
== &trace_uprobe_ops
;
78 static struct trace_uprobe
*to_trace_uprobe(struct dyn_event
*ev
)
80 return container_of(ev
, struct trace_uprobe
, devent
);
84 * for_each_trace_uprobe - iterate over the trace_uprobe list
85 * @pos: the struct trace_uprobe * for each entry
86 * @dpos: the struct dyn_event * to use as a loop cursor
88 #define for_each_trace_uprobe(pos, dpos) \
89 for_each_dyn_event(dpos) \
90 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
92 #define SIZEOF_TRACE_UPROBE(n) \
93 (offsetof(struct trace_uprobe, tp.args) + \
94 (sizeof(struct probe_arg) * (n)))
96 static int register_uprobe_event(struct trace_uprobe
*tu
);
97 static int unregister_uprobe_event(struct trace_uprobe
*tu
);
99 struct uprobe_dispatch_data
{
100 struct trace_uprobe
*tu
;
101 unsigned long bp_addr
;
104 static int uprobe_dispatcher(struct uprobe_consumer
*con
, struct pt_regs
*regs
);
105 static int uretprobe_dispatcher(struct uprobe_consumer
*con
,
106 unsigned long func
, struct pt_regs
*regs
);
108 #ifdef CONFIG_STACK_GROWSUP
109 static unsigned long adjust_stack_addr(unsigned long addr
, unsigned int n
)
111 return addr
- (n
* sizeof(long));
114 static unsigned long adjust_stack_addr(unsigned long addr
, unsigned int n
)
116 return addr
+ (n
* sizeof(long));
120 static unsigned long get_user_stack_nth(struct pt_regs
*regs
, unsigned int n
)
123 unsigned long addr
= user_stack_pointer(regs
);
125 addr
= adjust_stack_addr(addr
, n
);
127 if (copy_from_user(&ret
, (void __force __user
*) addr
, sizeof(ret
)))
134 * Uprobes-specific fetch functions
136 static nokprobe_inline
int
137 probe_mem_read(void *dest
, void *src
, size_t size
)
139 void __user
*vaddr
= (void __force __user
*)src
;
141 return copy_from_user(dest
, vaddr
, size
) ? -EFAULT
: 0;
144 static nokprobe_inline
int
145 probe_mem_read_user(void *dest
, void *src
, size_t size
)
147 return probe_mem_read(dest
, src
, size
);
151 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
152 * length and relative data location.
154 static nokprobe_inline
int
155 fetch_store_string(unsigned long addr
, void *dest
, void *base
)
158 u32 loc
= *(u32
*)dest
;
159 int maxlen
= get_loc_len(loc
);
160 u8
*dst
= get_loc_data(dest
, base
);
161 void __user
*src
= (void __force __user
*) addr
;
163 if (unlikely(!maxlen
))
166 if (addr
== FETCH_TOKEN_COMM
)
167 ret
= strlcpy(dst
, current
->comm
, maxlen
);
169 ret
= strncpy_from_user(dst
, src
, maxlen
);
175 * Include the terminating null byte. In this case it
176 * was copied by strncpy_from_user but not accounted
180 *(u32
*)dest
= make_data_loc(ret
, (void *)dst
- base
);
186 static nokprobe_inline
int
187 fetch_store_string_user(unsigned long addr
, void *dest
, void *base
)
189 return fetch_store_string(addr
, dest
, base
);
192 /* Return the length of string -- including null terminal byte */
193 static nokprobe_inline
int
194 fetch_store_strlen(unsigned long addr
)
197 void __user
*vaddr
= (void __force __user
*) addr
;
199 if (addr
== FETCH_TOKEN_COMM
)
200 len
= strlen(current
->comm
) + 1;
202 len
= strnlen_user(vaddr
, MAX_STRING_SIZE
);
204 return (len
> MAX_STRING_SIZE
) ? 0 : len
;
207 static nokprobe_inline
int
208 fetch_store_strlen_user(unsigned long addr
)
210 return fetch_store_strlen(addr
);
213 static unsigned long translate_user_vaddr(unsigned long file_offset
)
215 unsigned long base_addr
;
216 struct uprobe_dispatch_data
*udd
;
218 udd
= (void *) current
->utask
->vaddr
;
220 base_addr
= udd
->bp_addr
- udd
->tu
->offset
;
221 return base_addr
+ file_offset
;
224 /* Note that we don't verify it, since the code does not come from user space */
226 process_fetch_insn(struct fetch_insn
*code
, struct pt_regs
*regs
, void *dest
,
231 /* 1st stage: get value from context */
234 val
= regs_get_register(regs
, code
->param
);
237 val
= get_user_stack_nth(regs
, code
->param
);
239 case FETCH_OP_STACKP
:
240 val
= user_stack_pointer(regs
);
242 case FETCH_OP_RETVAL
:
243 val
= regs_return_value(regs
);
246 val
= code
->immediate
;
249 val
= FETCH_TOKEN_COMM
;
252 val
= translate_user_vaddr(code
->immediate
);
259 return process_fetch_insn_bottom(code
, val
, dest
, base
);
261 NOKPROBE_SYMBOL(process_fetch_insn
)
263 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter
*filter
)
265 rwlock_init(&filter
->rwlock
);
266 filter
->nr_systemwide
= 0;
267 INIT_LIST_HEAD(&filter
->perf_events
);
270 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter
*filter
)
272 return !filter
->nr_systemwide
&& list_empty(&filter
->perf_events
);
275 static inline bool is_ret_probe(struct trace_uprobe
*tu
)
277 return tu
->consumer
.ret_handler
!= NULL
;
280 static bool trace_uprobe_is_busy(struct dyn_event
*ev
)
282 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
284 return trace_probe_is_enabled(&tu
->tp
);
287 static bool trace_uprobe_match(const char *system
, const char *event
,
288 struct dyn_event
*ev
)
290 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
292 return strcmp(trace_probe_name(&tu
->tp
), event
) == 0 &&
293 (!system
|| strcmp(trace_probe_group_name(&tu
->tp
), system
) == 0);
297 * Allocate new trace_uprobe and initialize it (including uprobes).
299 static struct trace_uprobe
*
300 alloc_trace_uprobe(const char *group
, const char *event
, int nargs
, bool is_ret
)
302 struct trace_uprobe
*tu
;
305 tu
= kzalloc(SIZEOF_TRACE_UPROBE(nargs
), GFP_KERNEL
);
307 return ERR_PTR(-ENOMEM
);
309 ret
= trace_probe_init(&tu
->tp
, event
, group
);
313 dyn_event_init(&tu
->devent
, &trace_uprobe_ops
);
314 tu
->consumer
.handler
= uprobe_dispatcher
;
316 tu
->consumer
.ret_handler
= uretprobe_dispatcher
;
317 init_trace_uprobe_filter(&tu
->filter
);
326 static void free_trace_uprobe(struct trace_uprobe
*tu
)
332 trace_probe_cleanup(&tu
->tp
);
337 static struct trace_uprobe
*find_probe_event(const char *event
, const char *group
)
339 struct dyn_event
*pos
;
340 struct trace_uprobe
*tu
;
342 for_each_trace_uprobe(tu
, pos
)
343 if (strcmp(trace_probe_name(&tu
->tp
), event
) == 0 &&
344 strcmp(trace_probe_group_name(&tu
->tp
), group
) == 0)
350 /* Unregister a trace_uprobe and probe_event */
351 static int unregister_trace_uprobe(struct trace_uprobe
*tu
)
355 ret
= unregister_uprobe_event(tu
);
359 dyn_event_remove(&tu
->devent
);
360 free_trace_uprobe(tu
);
365 * Uprobe with multiple reference counter is not allowed. i.e.
366 * If inode and offset matches, reference counter offset *must*
367 * match as well. Though, there is one exception: If user is
368 * replacing old trace_uprobe with new one(same group/event),
369 * then we allow same uprobe with new reference counter as far
370 * as the new one does not conflict with any other existing
373 static struct trace_uprobe
*find_old_trace_uprobe(struct trace_uprobe
*new)
375 struct dyn_event
*pos
;
376 struct trace_uprobe
*tmp
, *old
= NULL
;
377 struct inode
*new_inode
= d_real_inode(new->path
.dentry
);
379 old
= find_probe_event(trace_probe_name(&new->tp
),
380 trace_probe_group_name(&new->tp
));
382 for_each_trace_uprobe(tmp
, pos
) {
383 if ((old
? old
!= tmp
: true) &&
384 new_inode
== d_real_inode(tmp
->path
.dentry
) &&
385 new->offset
== tmp
->offset
&&
386 new->ref_ctr_offset
!= tmp
->ref_ctr_offset
) {
387 pr_warn("Reference counter offset mismatch.");
388 return ERR_PTR(-EINVAL
);
394 /* Register a trace_uprobe and probe_event */
395 static int register_trace_uprobe(struct trace_uprobe
*tu
)
397 struct trace_uprobe
*old_tu
;
400 mutex_lock(&event_mutex
);
402 /* register as an event */
403 old_tu
= find_old_trace_uprobe(tu
);
404 if (IS_ERR(old_tu
)) {
405 ret
= PTR_ERR(old_tu
);
410 /* delete old event */
411 ret
= unregister_trace_uprobe(old_tu
);
416 ret
= register_uprobe_event(tu
);
418 pr_warn("Failed to register probe event(%d)\n", ret
);
422 dyn_event_add(&tu
->devent
);
425 mutex_unlock(&event_mutex
);
432 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
434 static int trace_uprobe_create(int argc
, const char **argv
)
436 struct trace_uprobe
*tu
;
437 const char *event
= NULL
, *group
= UPROBE_EVENT_SYSTEM
;
438 char *arg
, *filename
, *rctr
, *rctr_end
, *tmp
;
439 char buf
[MAX_EVENT_NAME_LEN
];
441 unsigned long offset
, ref_ctr_offset
;
442 bool is_return
= false;
448 switch (argv
[0][0]) {
461 if (argv
[0][1] == ':')
464 if (!strchr(argv
[1], '/'))
467 filename
= kstrdup(argv
[1], GFP_KERNEL
);
471 /* Find the last occurrence, in case the path contains ':' too. */
472 arg
= strrchr(filename
, ':');
473 if (!arg
|| !isdigit(arg
[1])) {
478 trace_probe_log_init("trace_uprobe", argc
, argv
);
479 trace_probe_log_set_index(1); /* filename is the 2nd argument */
482 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
484 trace_probe_log_err(0, FILE_NOT_FOUND
);
486 trace_probe_log_clear();
489 if (!d_is_reg(path
.dentry
)) {
490 trace_probe_log_err(0, NO_REGULAR_FILE
);
492 goto fail_address_parse
;
495 /* Parse reference counter offset if specified. */
496 rctr
= strchr(arg
, '(');
498 rctr_end
= strchr(rctr
, ')');
501 rctr_end
= rctr
+ strlen(rctr
);
502 trace_probe_log_err(rctr_end
- filename
,
504 goto fail_address_parse
;
505 } else if (rctr_end
[1] != '\0') {
507 trace_probe_log_err(rctr_end
+ 1 - filename
,
509 goto fail_address_parse
;
514 ret
= kstrtoul(rctr
, 0, &ref_ctr_offset
);
516 trace_probe_log_err(rctr
- filename
, BAD_REFCNT
);
517 goto fail_address_parse
;
521 /* Parse uprobe offset. */
522 ret
= kstrtoul(arg
, 0, &offset
);
524 trace_probe_log_err(arg
- filename
, BAD_UPROBE_OFFS
);
525 goto fail_address_parse
;
529 trace_probe_log_set_index(0);
531 ret
= traceprobe_parse_event_name(&event
, &group
, buf
,
534 goto fail_address_parse
;
539 tail
= kstrdup(kbasename(filename
), GFP_KERNEL
);
542 goto fail_address_parse
;
545 ptr
= strpbrk(tail
, ".-_");
549 snprintf(buf
, MAX_EVENT_NAME_LEN
, "%c_%s_0x%lx", 'p', tail
, offset
);
557 tu
= alloc_trace_uprobe(group
, event
, argc
, is_return
);
560 /* This must return -ENOMEM otherwise there is a bug */
561 WARN_ON_ONCE(ret
!= -ENOMEM
);
562 goto fail_address_parse
;
565 tu
->ref_ctr_offset
= ref_ctr_offset
;
567 tu
->filename
= filename
;
569 /* parse arguments */
570 for (i
= 0; i
< argc
&& i
< MAX_TRACE_ARGS
; i
++) {
571 tmp
= kstrdup(argv
[i
], GFP_KERNEL
);
577 trace_probe_log_set_index(i
+ 2);
578 ret
= traceprobe_parse_probe_arg(&tu
->tp
, i
, tmp
,
579 is_return
? TPARG_FL_RETURN
: 0);
585 ret
= traceprobe_set_print_fmt(&tu
->tp
, is_ret_probe(tu
));
589 ret
= register_trace_uprobe(tu
);
594 free_trace_uprobe(tu
);
596 trace_probe_log_clear();
600 trace_probe_log_clear();
607 static int create_or_delete_trace_uprobe(int argc
, char **argv
)
611 if (argv
[0][0] == '-')
612 return dyn_event_release(argc
, argv
, &trace_uprobe_ops
);
614 ret
= trace_uprobe_create(argc
, (const char **)argv
);
615 return ret
== -ECANCELED
? -EINVAL
: ret
;
618 static int trace_uprobe_release(struct dyn_event
*ev
)
620 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
622 return unregister_trace_uprobe(tu
);
625 /* Probes listing interfaces */
626 static int trace_uprobe_show(struct seq_file
*m
, struct dyn_event
*ev
)
628 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
629 char c
= is_ret_probe(tu
) ? 'r' : 'p';
632 seq_printf(m
, "%c:%s/%s %s:0x%0*lx", c
, trace_probe_group_name(&tu
->tp
),
633 trace_probe_name(&tu
->tp
), tu
->filename
,
634 (int)(sizeof(void *) * 2), tu
->offset
);
636 if (tu
->ref_ctr_offset
)
637 seq_printf(m
, "(0x%lx)", tu
->ref_ctr_offset
);
639 for (i
= 0; i
< tu
->tp
.nr_args
; i
++)
640 seq_printf(m
, " %s=%s", tu
->tp
.args
[i
].name
, tu
->tp
.args
[i
].comm
);
646 static int probes_seq_show(struct seq_file
*m
, void *v
)
648 struct dyn_event
*ev
= v
;
650 if (!is_trace_uprobe(ev
))
653 return trace_uprobe_show(m
, ev
);
656 static const struct seq_operations probes_seq_op
= {
657 .start
= dyn_event_seq_start
,
658 .next
= dyn_event_seq_next
,
659 .stop
= dyn_event_seq_stop
,
660 .show
= probes_seq_show
663 static int probes_open(struct inode
*inode
, struct file
*file
)
667 if ((file
->f_mode
& FMODE_WRITE
) && (file
->f_flags
& O_TRUNC
)) {
668 ret
= dyn_events_release_all(&trace_uprobe_ops
);
673 return seq_open(file
, &probes_seq_op
);
676 static ssize_t
probes_write(struct file
*file
, const char __user
*buffer
,
677 size_t count
, loff_t
*ppos
)
679 return trace_parse_run_command(file
, buffer
, count
, ppos
,
680 create_or_delete_trace_uprobe
);
683 static const struct file_operations uprobe_events_ops
= {
684 .owner
= THIS_MODULE
,
688 .release
= seq_release
,
689 .write
= probes_write
,
692 /* Probes profiling interfaces */
693 static int probes_profile_seq_show(struct seq_file
*m
, void *v
)
695 struct dyn_event
*ev
= v
;
696 struct trace_uprobe
*tu
;
698 if (!is_trace_uprobe(ev
))
701 tu
= to_trace_uprobe(ev
);
702 seq_printf(m
, " %s %-44s %15lu\n", tu
->filename
,
703 trace_probe_name(&tu
->tp
), tu
->nhit
);
707 static const struct seq_operations profile_seq_op
= {
708 .start
= dyn_event_seq_start
,
709 .next
= dyn_event_seq_next
,
710 .stop
= dyn_event_seq_stop
,
711 .show
= probes_profile_seq_show
714 static int profile_open(struct inode
*inode
, struct file
*file
)
716 return seq_open(file
, &profile_seq_op
);
719 static const struct file_operations uprobe_profile_ops
= {
720 .owner
= THIS_MODULE
,
721 .open
= profile_open
,
724 .release
= seq_release
,
727 struct uprobe_cpu_buffer
{
731 static struct uprobe_cpu_buffer __percpu
*uprobe_cpu_buffer
;
732 static int uprobe_buffer_refcnt
;
734 static int uprobe_buffer_init(void)
738 uprobe_cpu_buffer
= alloc_percpu(struct uprobe_cpu_buffer
);
739 if (uprobe_cpu_buffer
== NULL
)
742 for_each_possible_cpu(cpu
) {
743 struct page
*p
= alloc_pages_node(cpu_to_node(cpu
),
749 per_cpu_ptr(uprobe_cpu_buffer
, cpu
)->buf
= page_address(p
);
750 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer
, cpu
)->mutex
);
756 for_each_possible_cpu(cpu
) {
759 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer
, cpu
)->buf
);
762 free_percpu(uprobe_cpu_buffer
);
766 static int uprobe_buffer_enable(void)
770 BUG_ON(!mutex_is_locked(&event_mutex
));
772 if (uprobe_buffer_refcnt
++ == 0) {
773 ret
= uprobe_buffer_init();
775 uprobe_buffer_refcnt
--;
781 static void uprobe_buffer_disable(void)
785 BUG_ON(!mutex_is_locked(&event_mutex
));
787 if (--uprobe_buffer_refcnt
== 0) {
788 for_each_possible_cpu(cpu
)
789 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer
,
792 free_percpu(uprobe_cpu_buffer
);
793 uprobe_cpu_buffer
= NULL
;
797 static struct uprobe_cpu_buffer
*uprobe_buffer_get(void)
799 struct uprobe_cpu_buffer
*ucb
;
802 cpu
= raw_smp_processor_id();
803 ucb
= per_cpu_ptr(uprobe_cpu_buffer
, cpu
);
806 * Use per-cpu buffers for fastest access, but we might migrate
807 * so the mutex makes sure we have sole access to it.
809 mutex_lock(&ucb
->mutex
);
814 static void uprobe_buffer_put(struct uprobe_cpu_buffer
*ucb
)
816 mutex_unlock(&ucb
->mutex
);
819 static void __uprobe_trace_func(struct trace_uprobe
*tu
,
820 unsigned long func
, struct pt_regs
*regs
,
821 struct uprobe_cpu_buffer
*ucb
, int dsize
,
822 struct trace_event_file
*trace_file
)
824 struct uprobe_trace_entry_head
*entry
;
825 struct ring_buffer_event
*event
;
826 struct ring_buffer
*buffer
;
829 struct trace_event_call
*call
= trace_probe_event_call(&tu
->tp
);
831 WARN_ON(call
!= trace_file
->event_call
);
833 if (WARN_ON_ONCE(tu
->tp
.size
+ dsize
> PAGE_SIZE
))
836 if (trace_trigger_soft_disabled(trace_file
))
839 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
840 size
= esize
+ tu
->tp
.size
+ dsize
;
841 event
= trace_event_buffer_lock_reserve(&buffer
, trace_file
,
842 call
->event
.type
, size
, 0, 0);
846 entry
= ring_buffer_event_data(event
);
847 if (is_ret_probe(tu
)) {
848 entry
->vaddr
[0] = func
;
849 entry
->vaddr
[1] = instruction_pointer(regs
);
850 data
= DATAOF_TRACE_ENTRY(entry
, true);
852 entry
->vaddr
[0] = instruction_pointer(regs
);
853 data
= DATAOF_TRACE_ENTRY(entry
, false);
856 memcpy(data
, ucb
->buf
, tu
->tp
.size
+ dsize
);
858 event_trigger_unlock_commit(trace_file
, buffer
, event
, entry
, 0, 0);
862 static int uprobe_trace_func(struct trace_uprobe
*tu
, struct pt_regs
*regs
,
863 struct uprobe_cpu_buffer
*ucb
, int dsize
)
865 struct event_file_link
*link
;
867 if (is_ret_probe(tu
))
871 trace_probe_for_each_link_rcu(link
, &tu
->tp
)
872 __uprobe_trace_func(tu
, 0, regs
, ucb
, dsize
, link
->file
);
878 static void uretprobe_trace_func(struct trace_uprobe
*tu
, unsigned long func
,
879 struct pt_regs
*regs
,
880 struct uprobe_cpu_buffer
*ucb
, int dsize
)
882 struct event_file_link
*link
;
885 trace_probe_for_each_link_rcu(link
, &tu
->tp
)
886 __uprobe_trace_func(tu
, func
, regs
, ucb
, dsize
, link
->file
);
890 /* Event entry printers */
891 static enum print_line_t
892 print_uprobe_event(struct trace_iterator
*iter
, int flags
, struct trace_event
*event
)
894 struct uprobe_trace_entry_head
*entry
;
895 struct trace_seq
*s
= &iter
->seq
;
896 struct trace_uprobe
*tu
;
899 entry
= (struct uprobe_trace_entry_head
*)iter
->ent
;
900 tu
= container_of(event
, struct trace_uprobe
, tp
.call
.event
);
902 if (is_ret_probe(tu
)) {
903 trace_seq_printf(s
, "%s: (0x%lx <- 0x%lx)",
904 trace_probe_name(&tu
->tp
),
905 entry
->vaddr
[1], entry
->vaddr
[0]);
906 data
= DATAOF_TRACE_ENTRY(entry
, true);
908 trace_seq_printf(s
, "%s: (0x%lx)",
909 trace_probe_name(&tu
->tp
),
911 data
= DATAOF_TRACE_ENTRY(entry
, false);
914 if (print_probe_args(s
, tu
->tp
.args
, tu
->tp
.nr_args
, data
, entry
) < 0)
917 trace_seq_putc(s
, '\n');
920 return trace_handle_return(s
);
923 typedef bool (*filter_func_t
)(struct uprobe_consumer
*self
,
924 enum uprobe_filter_ctx ctx
,
925 struct mm_struct
*mm
);
928 probe_event_enable(struct trace_uprobe
*tu
, struct trace_event_file
*file
,
929 filter_func_t filter
)
931 bool enabled
= trace_probe_is_enabled(&tu
->tp
);
935 if (trace_probe_test_flag(&tu
->tp
, TP_FLAG_PROFILE
))
938 ret
= trace_probe_add_file(&tu
->tp
, file
);
942 if (trace_probe_test_flag(&tu
->tp
, TP_FLAG_TRACE
))
945 trace_probe_set_flag(&tu
->tp
, TP_FLAG_PROFILE
);
948 WARN_ON(!uprobe_filter_is_empty(&tu
->filter
));
953 ret
= uprobe_buffer_enable();
957 tu
->consumer
.filter
= filter
;
958 tu
->inode
= d_real_inode(tu
->path
.dentry
);
959 if (tu
->ref_ctr_offset
) {
960 ret
= uprobe_register_refctr(tu
->inode
, tu
->offset
,
961 tu
->ref_ctr_offset
, &tu
->consumer
);
963 ret
= uprobe_register(tu
->inode
, tu
->offset
, &tu
->consumer
);
972 uprobe_buffer_disable();
976 trace_probe_remove_file(&tu
->tp
, file
);
978 trace_probe_clear_flag(&tu
->tp
, TP_FLAG_PROFILE
);
984 probe_event_disable(struct trace_uprobe
*tu
, struct trace_event_file
*file
)
986 if (!trace_probe_is_enabled(&tu
->tp
))
990 if (trace_probe_remove_file(&tu
->tp
, file
) < 0)
993 if (trace_probe_is_enabled(&tu
->tp
))
996 trace_probe_clear_flag(&tu
->tp
, TP_FLAG_PROFILE
);
998 WARN_ON(!uprobe_filter_is_empty(&tu
->filter
));
1000 uprobe_unregister(tu
->inode
, tu
->offset
, &tu
->consumer
);
1003 uprobe_buffer_disable();
1006 static int uprobe_event_define_fields(struct trace_event_call
*event_call
)
1009 struct uprobe_trace_entry_head field
;
1010 struct trace_uprobe
*tu
= event_call
->data
;
1012 if (is_ret_probe(tu
)) {
1013 DEFINE_FIELD(unsigned long, vaddr
[0], FIELD_STRING_FUNC
, 0);
1014 DEFINE_FIELD(unsigned long, vaddr
[1], FIELD_STRING_RETIP
, 0);
1015 size
= SIZEOF_TRACE_ENTRY(true);
1017 DEFINE_FIELD(unsigned long, vaddr
[0], FIELD_STRING_IP
, 0);
1018 size
= SIZEOF_TRACE_ENTRY(false);
1021 return traceprobe_define_arg_fields(event_call
, size
, &tu
->tp
);
1024 #ifdef CONFIG_PERF_EVENTS
1026 __uprobe_perf_filter(struct trace_uprobe_filter
*filter
, struct mm_struct
*mm
)
1028 struct perf_event
*event
;
1030 if (filter
->nr_systemwide
)
1033 list_for_each_entry(event
, &filter
->perf_events
, hw
.tp_list
) {
1034 if (event
->hw
.target
->mm
== mm
)
1042 uprobe_filter_event(struct trace_uprobe
*tu
, struct perf_event
*event
)
1044 return __uprobe_perf_filter(&tu
->filter
, event
->hw
.target
->mm
);
1047 static int uprobe_perf_close(struct trace_uprobe
*tu
, struct perf_event
*event
)
1051 write_lock(&tu
->filter
.rwlock
);
1052 if (event
->hw
.target
) {
1053 list_del(&event
->hw
.tp_list
);
1054 done
= tu
->filter
.nr_systemwide
||
1055 (event
->hw
.target
->flags
& PF_EXITING
) ||
1056 uprobe_filter_event(tu
, event
);
1058 tu
->filter
.nr_systemwide
--;
1059 done
= tu
->filter
.nr_systemwide
;
1061 write_unlock(&tu
->filter
.rwlock
);
1064 return uprobe_apply(tu
->inode
, tu
->offset
, &tu
->consumer
, false);
1069 static int uprobe_perf_open(struct trace_uprobe
*tu
, struct perf_event
*event
)
1074 write_lock(&tu
->filter
.rwlock
);
1075 if (event
->hw
.target
) {
1077 * event->parent != NULL means copy_process(), we can avoid
1078 * uprobe_apply(). current->mm must be probed and we can rely
1079 * on dup_mmap() which preserves the already installed bp's.
1081 * attr.enable_on_exec means that exec/mmap will install the
1082 * breakpoints we need.
1084 done
= tu
->filter
.nr_systemwide
||
1085 event
->parent
|| event
->attr
.enable_on_exec
||
1086 uprobe_filter_event(tu
, event
);
1087 list_add(&event
->hw
.tp_list
, &tu
->filter
.perf_events
);
1089 done
= tu
->filter
.nr_systemwide
;
1090 tu
->filter
.nr_systemwide
++;
1092 write_unlock(&tu
->filter
.rwlock
);
1096 err
= uprobe_apply(tu
->inode
, tu
->offset
, &tu
->consumer
, true);
1098 uprobe_perf_close(tu
, event
);
1103 static bool uprobe_perf_filter(struct uprobe_consumer
*uc
,
1104 enum uprobe_filter_ctx ctx
, struct mm_struct
*mm
)
1106 struct trace_uprobe
*tu
;
1109 tu
= container_of(uc
, struct trace_uprobe
, consumer
);
1110 read_lock(&tu
->filter
.rwlock
);
1111 ret
= __uprobe_perf_filter(&tu
->filter
, mm
);
1112 read_unlock(&tu
->filter
.rwlock
);
1117 static void __uprobe_perf_func(struct trace_uprobe
*tu
,
1118 unsigned long func
, struct pt_regs
*regs
,
1119 struct uprobe_cpu_buffer
*ucb
, int dsize
)
1121 struct trace_event_call
*call
= trace_probe_event_call(&tu
->tp
);
1122 struct uprobe_trace_entry_head
*entry
;
1123 struct hlist_head
*head
;
1128 if (bpf_prog_array_valid(call
) && !trace_call_bpf(call
, regs
))
1131 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
1133 size
= esize
+ tu
->tp
.size
+ dsize
;
1134 size
= ALIGN(size
+ sizeof(u32
), sizeof(u64
)) - sizeof(u32
);
1135 if (WARN_ONCE(size
> PERF_MAX_TRACE_SIZE
, "profile buffer not large enough"))
1139 head
= this_cpu_ptr(call
->perf_events
);
1140 if (hlist_empty(head
))
1143 entry
= perf_trace_buf_alloc(size
, NULL
, &rctx
);
1147 if (is_ret_probe(tu
)) {
1148 entry
->vaddr
[0] = func
;
1149 entry
->vaddr
[1] = instruction_pointer(regs
);
1150 data
= DATAOF_TRACE_ENTRY(entry
, true);
1152 entry
->vaddr
[0] = instruction_pointer(regs
);
1153 data
= DATAOF_TRACE_ENTRY(entry
, false);
1156 memcpy(data
, ucb
->buf
, tu
->tp
.size
+ dsize
);
1158 if (size
- esize
> tu
->tp
.size
+ dsize
) {
1159 int len
= tu
->tp
.size
+ dsize
;
1161 memset(data
+ len
, 0, size
- esize
- len
);
1164 perf_trace_buf_submit(entry
, size
, rctx
, call
->event
.type
, 1, regs
,
1170 /* uprobe profile handler */
1171 static int uprobe_perf_func(struct trace_uprobe
*tu
, struct pt_regs
*regs
,
1172 struct uprobe_cpu_buffer
*ucb
, int dsize
)
1174 if (!uprobe_perf_filter(&tu
->consumer
, 0, current
->mm
))
1175 return UPROBE_HANDLER_REMOVE
;
1177 if (!is_ret_probe(tu
))
1178 __uprobe_perf_func(tu
, 0, regs
, ucb
, dsize
);
1182 static void uretprobe_perf_func(struct trace_uprobe
*tu
, unsigned long func
,
1183 struct pt_regs
*regs
,
1184 struct uprobe_cpu_buffer
*ucb
, int dsize
)
1186 __uprobe_perf_func(tu
, func
, regs
, ucb
, dsize
);
1189 int bpf_get_uprobe_info(const struct perf_event
*event
, u32
*fd_type
,
1190 const char **filename
, u64
*probe_offset
,
1191 bool perf_type_tracepoint
)
1193 const char *pevent
= trace_event_name(event
->tp_event
);
1194 const char *group
= event
->tp_event
->class->system
;
1195 struct trace_uprobe
*tu
;
1197 if (perf_type_tracepoint
)
1198 tu
= find_probe_event(pevent
, group
);
1200 tu
= event
->tp_event
->data
;
1204 *fd_type
= is_ret_probe(tu
) ? BPF_FD_TYPE_URETPROBE
1205 : BPF_FD_TYPE_UPROBE
;
1206 *filename
= tu
->filename
;
1207 *probe_offset
= tu
->offset
;
1210 #endif /* CONFIG_PERF_EVENTS */
1213 trace_uprobe_register(struct trace_event_call
*event
, enum trace_reg type
,
1216 struct trace_uprobe
*tu
= event
->data
;
1217 struct trace_event_file
*file
= data
;
1220 case TRACE_REG_REGISTER
:
1221 return probe_event_enable(tu
, file
, NULL
);
1223 case TRACE_REG_UNREGISTER
:
1224 probe_event_disable(tu
, file
);
1227 #ifdef CONFIG_PERF_EVENTS
1228 case TRACE_REG_PERF_REGISTER
:
1229 return probe_event_enable(tu
, NULL
, uprobe_perf_filter
);
1231 case TRACE_REG_PERF_UNREGISTER
:
1232 probe_event_disable(tu
, NULL
);
1235 case TRACE_REG_PERF_OPEN
:
1236 return uprobe_perf_open(tu
, data
);
1238 case TRACE_REG_PERF_CLOSE
:
1239 return uprobe_perf_close(tu
, data
);
1248 static int uprobe_dispatcher(struct uprobe_consumer
*con
, struct pt_regs
*regs
)
1250 struct trace_uprobe
*tu
;
1251 struct uprobe_dispatch_data udd
;
1252 struct uprobe_cpu_buffer
*ucb
;
1257 tu
= container_of(con
, struct trace_uprobe
, consumer
);
1261 udd
.bp_addr
= instruction_pointer(regs
);
1263 current
->utask
->vaddr
= (unsigned long) &udd
;
1265 if (WARN_ON_ONCE(!uprobe_cpu_buffer
))
1268 dsize
= __get_data_size(&tu
->tp
, regs
);
1269 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
1271 ucb
= uprobe_buffer_get();
1272 store_trace_args(ucb
->buf
, &tu
->tp
, regs
, esize
, dsize
);
1274 if (trace_probe_test_flag(&tu
->tp
, TP_FLAG_TRACE
))
1275 ret
|= uprobe_trace_func(tu
, regs
, ucb
, dsize
);
1277 #ifdef CONFIG_PERF_EVENTS
1278 if (trace_probe_test_flag(&tu
->tp
, TP_FLAG_PROFILE
))
1279 ret
|= uprobe_perf_func(tu
, regs
, ucb
, dsize
);
1281 uprobe_buffer_put(ucb
);
1285 static int uretprobe_dispatcher(struct uprobe_consumer
*con
,
1286 unsigned long func
, struct pt_regs
*regs
)
1288 struct trace_uprobe
*tu
;
1289 struct uprobe_dispatch_data udd
;
1290 struct uprobe_cpu_buffer
*ucb
;
1293 tu
= container_of(con
, struct trace_uprobe
, consumer
);
1298 current
->utask
->vaddr
= (unsigned long) &udd
;
1300 if (WARN_ON_ONCE(!uprobe_cpu_buffer
))
1303 dsize
= __get_data_size(&tu
->tp
, regs
);
1304 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
1306 ucb
= uprobe_buffer_get();
1307 store_trace_args(ucb
->buf
, &tu
->tp
, regs
, esize
, dsize
);
1309 if (trace_probe_test_flag(&tu
->tp
, TP_FLAG_TRACE
))
1310 uretprobe_trace_func(tu
, func
, regs
, ucb
, dsize
);
1312 #ifdef CONFIG_PERF_EVENTS
1313 if (trace_probe_test_flag(&tu
->tp
, TP_FLAG_PROFILE
))
1314 uretprobe_perf_func(tu
, func
, regs
, ucb
, dsize
);
1316 uprobe_buffer_put(ucb
);
1320 static struct trace_event_functions uprobe_funcs
= {
1321 .trace
= print_uprobe_event
1324 static inline void init_trace_event_call(struct trace_uprobe
*tu
)
1326 struct trace_event_call
*call
= trace_probe_event_call(&tu
->tp
);
1328 call
->event
.funcs
= &uprobe_funcs
;
1329 call
->class->define_fields
= uprobe_event_define_fields
;
1331 call
->flags
= TRACE_EVENT_FL_UPROBE
| TRACE_EVENT_FL_CAP_ANY
;
1332 call
->class->reg
= trace_uprobe_register
;
1336 static int register_uprobe_event(struct trace_uprobe
*tu
)
1338 init_trace_event_call(tu
);
1340 return trace_probe_register_event_call(&tu
->tp
);
1343 static int unregister_uprobe_event(struct trace_uprobe
*tu
)
1345 return trace_probe_unregister_event_call(&tu
->tp
);
1348 #ifdef CONFIG_PERF_EVENTS
1349 struct trace_event_call
*
1350 create_local_trace_uprobe(char *name
, unsigned long offs
,
1351 unsigned long ref_ctr_offset
, bool is_return
)
1353 struct trace_uprobe
*tu
;
1357 ret
= kern_path(name
, LOOKUP_FOLLOW
, &path
);
1359 return ERR_PTR(ret
);
1361 if (!d_is_reg(path
.dentry
)) {
1363 return ERR_PTR(-EINVAL
);
1367 * local trace_kprobes are not added to dyn_event, so they are never
1368 * searched in find_trace_kprobe(). Therefore, there is no concern of
1369 * duplicated name "DUMMY_EVENT" here.
1371 tu
= alloc_trace_uprobe(UPROBE_EVENT_SYSTEM
, "DUMMY_EVENT", 0,
1375 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1378 return ERR_CAST(tu
);
1383 tu
->ref_ctr_offset
= ref_ctr_offset
;
1384 tu
->filename
= kstrdup(name
, GFP_KERNEL
);
1385 init_trace_event_call(tu
);
1387 if (traceprobe_set_print_fmt(&tu
->tp
, is_ret_probe(tu
)) < 0) {
1392 return trace_probe_event_call(&tu
->tp
);
1394 free_trace_uprobe(tu
);
1395 return ERR_PTR(ret
);
1398 void destroy_local_trace_uprobe(struct trace_event_call
*event_call
)
1400 struct trace_uprobe
*tu
;
1402 tu
= container_of(event_call
, struct trace_uprobe
, tp
.call
);
1404 free_trace_uprobe(tu
);
1406 #endif /* CONFIG_PERF_EVENTS */
1408 /* Make a trace interface for controling probe points */
1409 static __init
int init_uprobe_trace(void)
1411 struct dentry
*d_tracer
;
1414 ret
= dyn_event_register(&trace_uprobe_ops
);
1418 d_tracer
= tracing_init_dentry();
1419 if (IS_ERR(d_tracer
))
1422 trace_create_file("uprobe_events", 0644, d_tracer
,
1423 NULL
, &uprobe_events_ops
);
1424 /* Profile interface */
1425 trace_create_file("uprobe_profile", 0444, d_tracer
,
1426 NULL
, &uprobe_profile_ops
);
1430 fs_initcall(init_uprobe_trace
);