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 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
145 * length and relative data location.
147 static nokprobe_inline
int
148 fetch_store_string(unsigned long addr
, void *dest
, void *base
)
151 u32 loc
= *(u32
*)dest
;
152 int maxlen
= get_loc_len(loc
);
153 u8
*dst
= get_loc_data(dest
, base
);
154 void __user
*src
= (void __force __user
*) addr
;
156 if (unlikely(!maxlen
))
159 ret
= strncpy_from_user(dst
, src
, maxlen
);
165 * Include the terminating null byte. In this case it
166 * was copied by strncpy_from_user but not accounted
170 *(u32
*)dest
= make_data_loc(ret
, (void *)dst
- base
);
176 /* Return the length of string -- including null terminal byte */
177 static nokprobe_inline
int
178 fetch_store_strlen(unsigned long addr
)
181 void __user
*vaddr
= (void __force __user
*) addr
;
183 len
= strnlen_user(vaddr
, MAX_STRING_SIZE
);
185 return (len
> MAX_STRING_SIZE
) ? 0 : len
;
188 static unsigned long translate_user_vaddr(unsigned long file_offset
)
190 unsigned long base_addr
;
191 struct uprobe_dispatch_data
*udd
;
193 udd
= (void *) current
->utask
->vaddr
;
195 base_addr
= udd
->bp_addr
- udd
->tu
->offset
;
196 return base_addr
+ file_offset
;
199 /* Note that we don't verify it, since the code does not come from user space */
201 process_fetch_insn(struct fetch_insn
*code
, struct pt_regs
*regs
, void *dest
,
206 /* 1st stage: get value from context */
209 val
= regs_get_register(regs
, code
->param
);
212 val
= get_user_stack_nth(regs
, code
->param
);
214 case FETCH_OP_STACKP
:
215 val
= user_stack_pointer(regs
);
217 case FETCH_OP_RETVAL
:
218 val
= regs_return_value(regs
);
221 val
= code
->immediate
;
224 val
= translate_user_vaddr(code
->immediate
);
231 return process_fetch_insn_bottom(code
, val
, dest
, base
);
233 NOKPROBE_SYMBOL(process_fetch_insn
)
235 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter
*filter
)
237 rwlock_init(&filter
->rwlock
);
238 filter
->nr_systemwide
= 0;
239 INIT_LIST_HEAD(&filter
->perf_events
);
242 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter
*filter
)
244 return !filter
->nr_systemwide
&& list_empty(&filter
->perf_events
);
247 static inline bool is_ret_probe(struct trace_uprobe
*tu
)
249 return tu
->consumer
.ret_handler
!= NULL
;
252 static bool trace_uprobe_is_busy(struct dyn_event
*ev
)
254 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
256 return trace_probe_is_enabled(&tu
->tp
);
259 static bool trace_uprobe_match(const char *system
, const char *event
,
260 struct dyn_event
*ev
)
262 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
264 return strcmp(trace_event_name(&tu
->tp
.call
), event
) == 0 &&
265 (!system
|| strcmp(tu
->tp
.call
.class->system
, system
) == 0);
269 * Allocate new trace_uprobe and initialize it (including uprobes).
271 static struct trace_uprobe
*
272 alloc_trace_uprobe(const char *group
, const char *event
, int nargs
, bool is_ret
)
274 struct trace_uprobe
*tu
;
276 if (!event
|| !is_good_name(event
))
277 return ERR_PTR(-EINVAL
);
279 if (!group
|| !is_good_name(group
))
280 return ERR_PTR(-EINVAL
);
282 tu
= kzalloc(SIZEOF_TRACE_UPROBE(nargs
), GFP_KERNEL
);
284 return ERR_PTR(-ENOMEM
);
286 tu
->tp
.call
.class = &tu
->tp
.class;
287 tu
->tp
.call
.name
= kstrdup(event
, GFP_KERNEL
);
288 if (!tu
->tp
.call
.name
)
291 tu
->tp
.class.system
= kstrdup(group
, GFP_KERNEL
);
292 if (!tu
->tp
.class.system
)
295 dyn_event_init(&tu
->devent
, &trace_uprobe_ops
);
296 INIT_LIST_HEAD(&tu
->tp
.files
);
297 tu
->consumer
.handler
= uprobe_dispatcher
;
299 tu
->consumer
.ret_handler
= uretprobe_dispatcher
;
300 init_trace_uprobe_filter(&tu
->filter
);
304 kfree(tu
->tp
.call
.name
);
307 return ERR_PTR(-ENOMEM
);
310 static void free_trace_uprobe(struct trace_uprobe
*tu
)
317 for (i
= 0; i
< tu
->tp
.nr_args
; i
++)
318 traceprobe_free_probe_arg(&tu
->tp
.args
[i
]);
321 kfree(tu
->tp
.call
.class->system
);
322 kfree(tu
->tp
.call
.name
);
327 static struct trace_uprobe
*find_probe_event(const char *event
, const char *group
)
329 struct dyn_event
*pos
;
330 struct trace_uprobe
*tu
;
332 for_each_trace_uprobe(tu
, pos
)
333 if (strcmp(trace_event_name(&tu
->tp
.call
), event
) == 0 &&
334 strcmp(tu
->tp
.call
.class->system
, group
) == 0)
340 /* Unregister a trace_uprobe and probe_event */
341 static int unregister_trace_uprobe(struct trace_uprobe
*tu
)
345 ret
= unregister_uprobe_event(tu
);
349 dyn_event_remove(&tu
->devent
);
350 free_trace_uprobe(tu
);
355 * Uprobe with multiple reference counter is not allowed. i.e.
356 * If inode and offset matches, reference counter offset *must*
357 * match as well. Though, there is one exception: If user is
358 * replacing old trace_uprobe with new one(same group/event),
359 * then we allow same uprobe with new reference counter as far
360 * as the new one does not conflict with any other existing
363 static struct trace_uprobe
*find_old_trace_uprobe(struct trace_uprobe
*new)
365 struct dyn_event
*pos
;
366 struct trace_uprobe
*tmp
, *old
= NULL
;
367 struct inode
*new_inode
= d_real_inode(new->path
.dentry
);
369 old
= find_probe_event(trace_event_name(&new->tp
.call
),
370 new->tp
.call
.class->system
);
372 for_each_trace_uprobe(tmp
, pos
) {
373 if ((old
? old
!= tmp
: true) &&
374 new_inode
== d_real_inode(tmp
->path
.dentry
) &&
375 new->offset
== tmp
->offset
&&
376 new->ref_ctr_offset
!= tmp
->ref_ctr_offset
) {
377 pr_warn("Reference counter offset mismatch.");
378 return ERR_PTR(-EINVAL
);
384 /* Register a trace_uprobe and probe_event */
385 static int register_trace_uprobe(struct trace_uprobe
*tu
)
387 struct trace_uprobe
*old_tu
;
390 mutex_lock(&event_mutex
);
392 /* register as an event */
393 old_tu
= find_old_trace_uprobe(tu
);
394 if (IS_ERR(old_tu
)) {
395 ret
= PTR_ERR(old_tu
);
400 /* delete old event */
401 ret
= unregister_trace_uprobe(old_tu
);
406 ret
= register_uprobe_event(tu
);
408 pr_warn("Failed to register probe event(%d)\n", ret
);
412 dyn_event_add(&tu
->devent
);
415 mutex_unlock(&event_mutex
);
422 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
424 * - Remove uprobe: -:[GRP/]EVENT
426 static int trace_uprobe_create(int argc
, const char **argv
)
428 struct trace_uprobe
*tu
;
429 const char *event
= NULL
, *group
= UPROBE_EVENT_SYSTEM
;
430 char *arg
, *filename
, *rctr
, *rctr_end
, *tmp
;
431 char buf
[MAX_EVENT_NAME_LEN
];
433 unsigned long offset
, ref_ctr_offset
;
434 bool is_return
= false;
440 /* argc must be >= 1 */
441 if (argv
[0][0] == 'r')
443 else if (argv
[0][0] != 'p' || argc
< 2)
446 if (argv
[0][1] == ':')
449 if (!strchr(argv
[1], '/'))
452 filename
= kstrdup(argv
[1], GFP_KERNEL
);
456 /* Find the last occurrence, in case the path contains ':' too. */
457 arg
= strrchr(filename
, ':');
458 if (!arg
|| !isdigit(arg
[1])) {
464 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
469 if (!d_is_reg(path
.dentry
)) {
471 goto fail_address_parse
;
474 /* Parse reference counter offset if specified. */
475 rctr
= strchr(arg
, '(');
477 rctr_end
= strchr(rctr
, ')');
478 if (rctr
> rctr_end
|| *(rctr_end
+ 1) != 0) {
480 pr_info("Invalid reference counter offset.\n");
481 goto fail_address_parse
;
486 ret
= kstrtoul(rctr
, 0, &ref_ctr_offset
);
488 pr_info("Invalid reference counter offset.\n");
489 goto fail_address_parse
;
493 /* Parse uprobe offset. */
494 ret
= kstrtoul(arg
, 0, &offset
);
496 goto fail_address_parse
;
503 ret
= traceprobe_parse_event_name(&event
, &group
, buf
);
505 goto fail_address_parse
;
510 tail
= kstrdup(kbasename(filename
), GFP_KERNEL
);
513 goto fail_address_parse
;
516 ptr
= strpbrk(tail
, ".-_");
520 snprintf(buf
, MAX_EVENT_NAME_LEN
, "%c_%s_0x%lx", 'p', tail
, offset
);
525 tu
= alloc_trace_uprobe(group
, event
, argc
, is_return
);
527 pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu
));
529 goto fail_address_parse
;
532 tu
->ref_ctr_offset
= ref_ctr_offset
;
534 tu
->filename
= filename
;
536 /* parse arguments */
537 for (i
= 0; i
< argc
&& i
< MAX_TRACE_ARGS
; i
++) {
538 tmp
= kstrdup(argv
[i
], GFP_KERNEL
);
544 ret
= traceprobe_parse_probe_arg(&tu
->tp
, i
, tmp
,
545 is_return
? TPARG_FL_RETURN
: 0);
551 ret
= register_trace_uprobe(tu
);
557 free_trace_uprobe(tu
);
564 pr_info("Failed to parse address or file.\n");
569 static int create_or_delete_trace_uprobe(int argc
, char **argv
)
573 if (argv
[0][0] == '-')
574 return dyn_event_release(argc
, argv
, &trace_uprobe_ops
);
576 ret
= trace_uprobe_create(argc
, (const char **)argv
);
577 return ret
== -ECANCELED
? -EINVAL
: ret
;
580 static int trace_uprobe_release(struct dyn_event
*ev
)
582 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
584 return unregister_trace_uprobe(tu
);
587 /* Probes listing interfaces */
588 static int trace_uprobe_show(struct seq_file
*m
, struct dyn_event
*ev
)
590 struct trace_uprobe
*tu
= to_trace_uprobe(ev
);
591 char c
= is_ret_probe(tu
) ? 'r' : 'p';
594 seq_printf(m
, "%c:%s/%s %s:0x%0*lx", c
, tu
->tp
.call
.class->system
,
595 trace_event_name(&tu
->tp
.call
), tu
->filename
,
596 (int)(sizeof(void *) * 2), tu
->offset
);
598 if (tu
->ref_ctr_offset
)
599 seq_printf(m
, "(0x%lx)", tu
->ref_ctr_offset
);
601 for (i
= 0; i
< tu
->tp
.nr_args
; i
++)
602 seq_printf(m
, " %s=%s", tu
->tp
.args
[i
].name
, tu
->tp
.args
[i
].comm
);
608 static int probes_seq_show(struct seq_file
*m
, void *v
)
610 struct dyn_event
*ev
= v
;
612 if (!is_trace_uprobe(ev
))
615 return trace_uprobe_show(m
, ev
);
618 static const struct seq_operations probes_seq_op
= {
619 .start
= dyn_event_seq_start
,
620 .next
= dyn_event_seq_next
,
621 .stop
= dyn_event_seq_stop
,
622 .show
= probes_seq_show
625 static int probes_open(struct inode
*inode
, struct file
*file
)
629 if ((file
->f_mode
& FMODE_WRITE
) && (file
->f_flags
& O_TRUNC
)) {
630 ret
= dyn_events_release_all(&trace_uprobe_ops
);
635 return seq_open(file
, &probes_seq_op
);
638 static ssize_t
probes_write(struct file
*file
, const char __user
*buffer
,
639 size_t count
, loff_t
*ppos
)
641 return trace_parse_run_command(file
, buffer
, count
, ppos
,
642 create_or_delete_trace_uprobe
);
645 static const struct file_operations uprobe_events_ops
= {
646 .owner
= THIS_MODULE
,
650 .release
= seq_release
,
651 .write
= probes_write
,
654 /* Probes profiling interfaces */
655 static int probes_profile_seq_show(struct seq_file
*m
, void *v
)
657 struct dyn_event
*ev
= v
;
658 struct trace_uprobe
*tu
;
660 if (!is_trace_uprobe(ev
))
663 tu
= to_trace_uprobe(ev
);
664 seq_printf(m
, " %s %-44s %15lu\n", tu
->filename
,
665 trace_event_name(&tu
->tp
.call
), tu
->nhit
);
669 static const struct seq_operations profile_seq_op
= {
670 .start
= dyn_event_seq_start
,
671 .next
= dyn_event_seq_next
,
672 .stop
= dyn_event_seq_stop
,
673 .show
= probes_profile_seq_show
676 static int profile_open(struct inode
*inode
, struct file
*file
)
678 return seq_open(file
, &profile_seq_op
);
681 static const struct file_operations uprobe_profile_ops
= {
682 .owner
= THIS_MODULE
,
683 .open
= profile_open
,
686 .release
= seq_release
,
689 struct uprobe_cpu_buffer
{
693 static struct uprobe_cpu_buffer __percpu
*uprobe_cpu_buffer
;
694 static int uprobe_buffer_refcnt
;
696 static int uprobe_buffer_init(void)
700 uprobe_cpu_buffer
= alloc_percpu(struct uprobe_cpu_buffer
);
701 if (uprobe_cpu_buffer
== NULL
)
704 for_each_possible_cpu(cpu
) {
705 struct page
*p
= alloc_pages_node(cpu_to_node(cpu
),
711 per_cpu_ptr(uprobe_cpu_buffer
, cpu
)->buf
= page_address(p
);
712 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer
, cpu
)->mutex
);
718 for_each_possible_cpu(cpu
) {
721 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer
, cpu
)->buf
);
724 free_percpu(uprobe_cpu_buffer
);
728 static int uprobe_buffer_enable(void)
732 BUG_ON(!mutex_is_locked(&event_mutex
));
734 if (uprobe_buffer_refcnt
++ == 0) {
735 ret
= uprobe_buffer_init();
737 uprobe_buffer_refcnt
--;
743 static void uprobe_buffer_disable(void)
747 BUG_ON(!mutex_is_locked(&event_mutex
));
749 if (--uprobe_buffer_refcnt
== 0) {
750 for_each_possible_cpu(cpu
)
751 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer
,
754 free_percpu(uprobe_cpu_buffer
);
755 uprobe_cpu_buffer
= NULL
;
759 static struct uprobe_cpu_buffer
*uprobe_buffer_get(void)
761 struct uprobe_cpu_buffer
*ucb
;
764 cpu
= raw_smp_processor_id();
765 ucb
= per_cpu_ptr(uprobe_cpu_buffer
, cpu
);
768 * Use per-cpu buffers for fastest access, but we might migrate
769 * so the mutex makes sure we have sole access to it.
771 mutex_lock(&ucb
->mutex
);
776 static void uprobe_buffer_put(struct uprobe_cpu_buffer
*ucb
)
778 mutex_unlock(&ucb
->mutex
);
781 static void __uprobe_trace_func(struct trace_uprobe
*tu
,
782 unsigned long func
, struct pt_regs
*regs
,
783 struct uprobe_cpu_buffer
*ucb
, int dsize
,
784 struct trace_event_file
*trace_file
)
786 struct uprobe_trace_entry_head
*entry
;
787 struct ring_buffer_event
*event
;
788 struct ring_buffer
*buffer
;
791 struct trace_event_call
*call
= &tu
->tp
.call
;
793 WARN_ON(call
!= trace_file
->event_call
);
795 if (WARN_ON_ONCE(tu
->tp
.size
+ dsize
> PAGE_SIZE
))
798 if (trace_trigger_soft_disabled(trace_file
))
801 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
802 size
= esize
+ tu
->tp
.size
+ dsize
;
803 event
= trace_event_buffer_lock_reserve(&buffer
, trace_file
,
804 call
->event
.type
, size
, 0, 0);
808 entry
= ring_buffer_event_data(event
);
809 if (is_ret_probe(tu
)) {
810 entry
->vaddr
[0] = func
;
811 entry
->vaddr
[1] = instruction_pointer(regs
);
812 data
= DATAOF_TRACE_ENTRY(entry
, true);
814 entry
->vaddr
[0] = instruction_pointer(regs
);
815 data
= DATAOF_TRACE_ENTRY(entry
, false);
818 memcpy(data
, ucb
->buf
, tu
->tp
.size
+ dsize
);
820 event_trigger_unlock_commit(trace_file
, buffer
, event
, entry
, 0, 0);
824 static int uprobe_trace_func(struct trace_uprobe
*tu
, struct pt_regs
*regs
,
825 struct uprobe_cpu_buffer
*ucb
, int dsize
)
827 struct event_file_link
*link
;
829 if (is_ret_probe(tu
))
833 list_for_each_entry_rcu(link
, &tu
->tp
.files
, list
)
834 __uprobe_trace_func(tu
, 0, regs
, ucb
, dsize
, link
->file
);
840 static void uretprobe_trace_func(struct trace_uprobe
*tu
, unsigned long func
,
841 struct pt_regs
*regs
,
842 struct uprobe_cpu_buffer
*ucb
, int dsize
)
844 struct event_file_link
*link
;
847 list_for_each_entry_rcu(link
, &tu
->tp
.files
, list
)
848 __uprobe_trace_func(tu
, func
, regs
, ucb
, dsize
, link
->file
);
852 /* Event entry printers */
853 static enum print_line_t
854 print_uprobe_event(struct trace_iterator
*iter
, int flags
, struct trace_event
*event
)
856 struct uprobe_trace_entry_head
*entry
;
857 struct trace_seq
*s
= &iter
->seq
;
858 struct trace_uprobe
*tu
;
861 entry
= (struct uprobe_trace_entry_head
*)iter
->ent
;
862 tu
= container_of(event
, struct trace_uprobe
, tp
.call
.event
);
864 if (is_ret_probe(tu
)) {
865 trace_seq_printf(s
, "%s: (0x%lx <- 0x%lx)",
866 trace_event_name(&tu
->tp
.call
),
867 entry
->vaddr
[1], entry
->vaddr
[0]);
868 data
= DATAOF_TRACE_ENTRY(entry
, true);
870 trace_seq_printf(s
, "%s: (0x%lx)",
871 trace_event_name(&tu
->tp
.call
),
873 data
= DATAOF_TRACE_ENTRY(entry
, false);
876 if (print_probe_args(s
, tu
->tp
.args
, tu
->tp
.nr_args
, data
, entry
) < 0)
879 trace_seq_putc(s
, '\n');
882 return trace_handle_return(s
);
885 typedef bool (*filter_func_t
)(struct uprobe_consumer
*self
,
886 enum uprobe_filter_ctx ctx
,
887 struct mm_struct
*mm
);
890 probe_event_enable(struct trace_uprobe
*tu
, struct trace_event_file
*file
,
891 filter_func_t filter
)
893 bool enabled
= trace_probe_is_enabled(&tu
->tp
);
894 struct event_file_link
*link
= NULL
;
898 if (tu
->tp
.flags
& TP_FLAG_PROFILE
)
901 link
= kmalloc(sizeof(*link
), GFP_KERNEL
);
906 list_add_tail_rcu(&link
->list
, &tu
->tp
.files
);
908 tu
->tp
.flags
|= TP_FLAG_TRACE
;
910 if (tu
->tp
.flags
& TP_FLAG_TRACE
)
913 tu
->tp
.flags
|= TP_FLAG_PROFILE
;
916 WARN_ON(!uprobe_filter_is_empty(&tu
->filter
));
921 ret
= uprobe_buffer_enable();
925 tu
->consumer
.filter
= filter
;
926 tu
->inode
= d_real_inode(tu
->path
.dentry
);
927 if (tu
->ref_ctr_offset
) {
928 ret
= uprobe_register_refctr(tu
->inode
, tu
->offset
,
929 tu
->ref_ctr_offset
, &tu
->consumer
);
931 ret
= uprobe_register(tu
->inode
, tu
->offset
, &tu
->consumer
);
940 uprobe_buffer_disable();
944 list_del(&link
->list
);
946 tu
->tp
.flags
&= ~TP_FLAG_TRACE
;
948 tu
->tp
.flags
&= ~TP_FLAG_PROFILE
;
954 probe_event_disable(struct trace_uprobe
*tu
, struct trace_event_file
*file
)
956 if (!trace_probe_is_enabled(&tu
->tp
))
960 struct event_file_link
*link
;
962 link
= find_event_file_link(&tu
->tp
, file
);
966 list_del_rcu(&link
->list
);
967 /* synchronize with u{,ret}probe_trace_func */
971 if (!list_empty(&tu
->tp
.files
))
975 WARN_ON(!uprobe_filter_is_empty(&tu
->filter
));
977 uprobe_unregister(tu
->inode
, tu
->offset
, &tu
->consumer
);
979 tu
->tp
.flags
&= file
? ~TP_FLAG_TRACE
: ~TP_FLAG_PROFILE
;
981 uprobe_buffer_disable();
984 static int uprobe_event_define_fields(struct trace_event_call
*event_call
)
987 struct uprobe_trace_entry_head field
;
988 struct trace_uprobe
*tu
= event_call
->data
;
990 if (is_ret_probe(tu
)) {
991 DEFINE_FIELD(unsigned long, vaddr
[0], FIELD_STRING_FUNC
, 0);
992 DEFINE_FIELD(unsigned long, vaddr
[1], FIELD_STRING_RETIP
, 0);
993 size
= SIZEOF_TRACE_ENTRY(true);
995 DEFINE_FIELD(unsigned long, vaddr
[0], FIELD_STRING_IP
, 0);
996 size
= SIZEOF_TRACE_ENTRY(false);
999 return traceprobe_define_arg_fields(event_call
, size
, &tu
->tp
);
1002 #ifdef CONFIG_PERF_EVENTS
1004 __uprobe_perf_filter(struct trace_uprobe_filter
*filter
, struct mm_struct
*mm
)
1006 struct perf_event
*event
;
1008 if (filter
->nr_systemwide
)
1011 list_for_each_entry(event
, &filter
->perf_events
, hw
.tp_list
) {
1012 if (event
->hw
.target
->mm
== mm
)
1020 uprobe_filter_event(struct trace_uprobe
*tu
, struct perf_event
*event
)
1022 return __uprobe_perf_filter(&tu
->filter
, event
->hw
.target
->mm
);
1025 static int uprobe_perf_close(struct trace_uprobe
*tu
, struct perf_event
*event
)
1029 write_lock(&tu
->filter
.rwlock
);
1030 if (event
->hw
.target
) {
1031 list_del(&event
->hw
.tp_list
);
1032 done
= tu
->filter
.nr_systemwide
||
1033 (event
->hw
.target
->flags
& PF_EXITING
) ||
1034 uprobe_filter_event(tu
, event
);
1036 tu
->filter
.nr_systemwide
--;
1037 done
= tu
->filter
.nr_systemwide
;
1039 write_unlock(&tu
->filter
.rwlock
);
1042 return uprobe_apply(tu
->inode
, tu
->offset
, &tu
->consumer
, false);
1047 static int uprobe_perf_open(struct trace_uprobe
*tu
, struct perf_event
*event
)
1052 write_lock(&tu
->filter
.rwlock
);
1053 if (event
->hw
.target
) {
1055 * event->parent != NULL means copy_process(), we can avoid
1056 * uprobe_apply(). current->mm must be probed and we can rely
1057 * on dup_mmap() which preserves the already installed bp's.
1059 * attr.enable_on_exec means that exec/mmap will install the
1060 * breakpoints we need.
1062 done
= tu
->filter
.nr_systemwide
||
1063 event
->parent
|| event
->attr
.enable_on_exec
||
1064 uprobe_filter_event(tu
, event
);
1065 list_add(&event
->hw
.tp_list
, &tu
->filter
.perf_events
);
1067 done
= tu
->filter
.nr_systemwide
;
1068 tu
->filter
.nr_systemwide
++;
1070 write_unlock(&tu
->filter
.rwlock
);
1074 err
= uprobe_apply(tu
->inode
, tu
->offset
, &tu
->consumer
, true);
1076 uprobe_perf_close(tu
, event
);
1081 static bool uprobe_perf_filter(struct uprobe_consumer
*uc
,
1082 enum uprobe_filter_ctx ctx
, struct mm_struct
*mm
)
1084 struct trace_uprobe
*tu
;
1087 tu
= container_of(uc
, struct trace_uprobe
, consumer
);
1088 read_lock(&tu
->filter
.rwlock
);
1089 ret
= __uprobe_perf_filter(&tu
->filter
, mm
);
1090 read_unlock(&tu
->filter
.rwlock
);
1095 static void __uprobe_perf_func(struct trace_uprobe
*tu
,
1096 unsigned long func
, struct pt_regs
*regs
,
1097 struct uprobe_cpu_buffer
*ucb
, int dsize
)
1099 struct trace_event_call
*call
= &tu
->tp
.call
;
1100 struct uprobe_trace_entry_head
*entry
;
1101 struct hlist_head
*head
;
1106 if (bpf_prog_array_valid(call
) && !trace_call_bpf(call
, regs
))
1109 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
1111 size
= esize
+ tu
->tp
.size
+ dsize
;
1112 size
= ALIGN(size
+ sizeof(u32
), sizeof(u64
)) - sizeof(u32
);
1113 if (WARN_ONCE(size
> PERF_MAX_TRACE_SIZE
, "profile buffer not large enough"))
1117 head
= this_cpu_ptr(call
->perf_events
);
1118 if (hlist_empty(head
))
1121 entry
= perf_trace_buf_alloc(size
, NULL
, &rctx
);
1125 if (is_ret_probe(tu
)) {
1126 entry
->vaddr
[0] = func
;
1127 entry
->vaddr
[1] = instruction_pointer(regs
);
1128 data
= DATAOF_TRACE_ENTRY(entry
, true);
1130 entry
->vaddr
[0] = instruction_pointer(regs
);
1131 data
= DATAOF_TRACE_ENTRY(entry
, false);
1134 memcpy(data
, ucb
->buf
, tu
->tp
.size
+ dsize
);
1136 if (size
- esize
> tu
->tp
.size
+ dsize
) {
1137 int len
= tu
->tp
.size
+ dsize
;
1139 memset(data
+ len
, 0, size
- esize
- len
);
1142 perf_trace_buf_submit(entry
, size
, rctx
, call
->event
.type
, 1, regs
,
1148 /* uprobe profile handler */
1149 static int uprobe_perf_func(struct trace_uprobe
*tu
, struct pt_regs
*regs
,
1150 struct uprobe_cpu_buffer
*ucb
, int dsize
)
1152 if (!uprobe_perf_filter(&tu
->consumer
, 0, current
->mm
))
1153 return UPROBE_HANDLER_REMOVE
;
1155 if (!is_ret_probe(tu
))
1156 __uprobe_perf_func(tu
, 0, regs
, ucb
, dsize
);
1160 static void uretprobe_perf_func(struct trace_uprobe
*tu
, unsigned long func
,
1161 struct pt_regs
*regs
,
1162 struct uprobe_cpu_buffer
*ucb
, int dsize
)
1164 __uprobe_perf_func(tu
, func
, regs
, ucb
, dsize
);
1167 int bpf_get_uprobe_info(const struct perf_event
*event
, u32
*fd_type
,
1168 const char **filename
, u64
*probe_offset
,
1169 bool perf_type_tracepoint
)
1171 const char *pevent
= trace_event_name(event
->tp_event
);
1172 const char *group
= event
->tp_event
->class->system
;
1173 struct trace_uprobe
*tu
;
1175 if (perf_type_tracepoint
)
1176 tu
= find_probe_event(pevent
, group
);
1178 tu
= event
->tp_event
->data
;
1182 *fd_type
= is_ret_probe(tu
) ? BPF_FD_TYPE_URETPROBE
1183 : BPF_FD_TYPE_UPROBE
;
1184 *filename
= tu
->filename
;
1185 *probe_offset
= tu
->offset
;
1188 #endif /* CONFIG_PERF_EVENTS */
1191 trace_uprobe_register(struct trace_event_call
*event
, enum trace_reg type
,
1194 struct trace_uprobe
*tu
= event
->data
;
1195 struct trace_event_file
*file
= data
;
1198 case TRACE_REG_REGISTER
:
1199 return probe_event_enable(tu
, file
, NULL
);
1201 case TRACE_REG_UNREGISTER
:
1202 probe_event_disable(tu
, file
);
1205 #ifdef CONFIG_PERF_EVENTS
1206 case TRACE_REG_PERF_REGISTER
:
1207 return probe_event_enable(tu
, NULL
, uprobe_perf_filter
);
1209 case TRACE_REG_PERF_UNREGISTER
:
1210 probe_event_disable(tu
, NULL
);
1213 case TRACE_REG_PERF_OPEN
:
1214 return uprobe_perf_open(tu
, data
);
1216 case TRACE_REG_PERF_CLOSE
:
1217 return uprobe_perf_close(tu
, data
);
1226 static int uprobe_dispatcher(struct uprobe_consumer
*con
, struct pt_regs
*regs
)
1228 struct trace_uprobe
*tu
;
1229 struct uprobe_dispatch_data udd
;
1230 struct uprobe_cpu_buffer
*ucb
;
1235 tu
= container_of(con
, struct trace_uprobe
, consumer
);
1239 udd
.bp_addr
= instruction_pointer(regs
);
1241 current
->utask
->vaddr
= (unsigned long) &udd
;
1243 if (WARN_ON_ONCE(!uprobe_cpu_buffer
))
1246 dsize
= __get_data_size(&tu
->tp
, regs
);
1247 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
1249 ucb
= uprobe_buffer_get();
1250 store_trace_args(ucb
->buf
, &tu
->tp
, regs
, esize
, dsize
);
1252 if (tu
->tp
.flags
& TP_FLAG_TRACE
)
1253 ret
|= uprobe_trace_func(tu
, regs
, ucb
, dsize
);
1255 #ifdef CONFIG_PERF_EVENTS
1256 if (tu
->tp
.flags
& TP_FLAG_PROFILE
)
1257 ret
|= uprobe_perf_func(tu
, regs
, ucb
, dsize
);
1259 uprobe_buffer_put(ucb
);
1263 static int uretprobe_dispatcher(struct uprobe_consumer
*con
,
1264 unsigned long func
, struct pt_regs
*regs
)
1266 struct trace_uprobe
*tu
;
1267 struct uprobe_dispatch_data udd
;
1268 struct uprobe_cpu_buffer
*ucb
;
1271 tu
= container_of(con
, struct trace_uprobe
, consumer
);
1276 current
->utask
->vaddr
= (unsigned long) &udd
;
1278 if (WARN_ON_ONCE(!uprobe_cpu_buffer
))
1281 dsize
= __get_data_size(&tu
->tp
, regs
);
1282 esize
= SIZEOF_TRACE_ENTRY(is_ret_probe(tu
));
1284 ucb
= uprobe_buffer_get();
1285 store_trace_args(ucb
->buf
, &tu
->tp
, regs
, esize
, dsize
);
1287 if (tu
->tp
.flags
& TP_FLAG_TRACE
)
1288 uretprobe_trace_func(tu
, func
, regs
, ucb
, dsize
);
1290 #ifdef CONFIG_PERF_EVENTS
1291 if (tu
->tp
.flags
& TP_FLAG_PROFILE
)
1292 uretprobe_perf_func(tu
, func
, regs
, ucb
, dsize
);
1294 uprobe_buffer_put(ucb
);
1298 static struct trace_event_functions uprobe_funcs
= {
1299 .trace
= print_uprobe_event
1302 static inline void init_trace_event_call(struct trace_uprobe
*tu
,
1303 struct trace_event_call
*call
)
1305 INIT_LIST_HEAD(&call
->class->fields
);
1306 call
->event
.funcs
= &uprobe_funcs
;
1307 call
->class->define_fields
= uprobe_event_define_fields
;
1309 call
->flags
= TRACE_EVENT_FL_UPROBE
;
1310 call
->class->reg
= trace_uprobe_register
;
1314 static int register_uprobe_event(struct trace_uprobe
*tu
)
1316 struct trace_event_call
*call
= &tu
->tp
.call
;
1319 init_trace_event_call(tu
, call
);
1321 if (traceprobe_set_print_fmt(&tu
->tp
, is_ret_probe(tu
)) < 0)
1324 ret
= register_trace_event(&call
->event
);
1326 kfree(call
->print_fmt
);
1330 ret
= trace_add_event_call(call
);
1333 pr_info("Failed to register uprobe event: %s\n",
1334 trace_event_name(call
));
1335 kfree(call
->print_fmt
);
1336 unregister_trace_event(&call
->event
);
1342 static int unregister_uprobe_event(struct trace_uprobe
*tu
)
1346 /* tu->event is unregistered in trace_remove_event_call() */
1347 ret
= trace_remove_event_call(&tu
->tp
.call
);
1350 kfree(tu
->tp
.call
.print_fmt
);
1351 tu
->tp
.call
.print_fmt
= NULL
;
1355 #ifdef CONFIG_PERF_EVENTS
1356 struct trace_event_call
*
1357 create_local_trace_uprobe(char *name
, unsigned long offs
,
1358 unsigned long ref_ctr_offset
, bool is_return
)
1360 struct trace_uprobe
*tu
;
1364 ret
= kern_path(name
, LOOKUP_FOLLOW
, &path
);
1366 return ERR_PTR(ret
);
1368 if (!d_is_reg(path
.dentry
)) {
1370 return ERR_PTR(-EINVAL
);
1374 * local trace_kprobes are not added to dyn_event, so they are never
1375 * searched in find_trace_kprobe(). Therefore, there is no concern of
1376 * duplicated name "DUMMY_EVENT" here.
1378 tu
= alloc_trace_uprobe(UPROBE_EVENT_SYSTEM
, "DUMMY_EVENT", 0,
1382 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1385 return ERR_CAST(tu
);
1390 tu
->ref_ctr_offset
= ref_ctr_offset
;
1391 tu
->filename
= kstrdup(name
, GFP_KERNEL
);
1392 init_trace_event_call(tu
, &tu
->tp
.call
);
1394 if (traceprobe_set_print_fmt(&tu
->tp
, is_ret_probe(tu
)) < 0) {
1399 return &tu
->tp
.call
;
1401 free_trace_uprobe(tu
);
1402 return ERR_PTR(ret
);
1405 void destroy_local_trace_uprobe(struct trace_event_call
*event_call
)
1407 struct trace_uprobe
*tu
;
1409 tu
= container_of(event_call
, struct trace_uprobe
, tp
.call
);
1411 kfree(tu
->tp
.call
.print_fmt
);
1412 tu
->tp
.call
.print_fmt
= NULL
;
1414 free_trace_uprobe(tu
);
1416 #endif /* CONFIG_PERF_EVENTS */
1418 /* Make a trace interface for controling probe points */
1419 static __init
int init_uprobe_trace(void)
1421 struct dentry
*d_tracer
;
1424 ret
= dyn_event_register(&trace_uprobe_ops
);
1428 d_tracer
= tracing_init_dentry();
1429 if (IS_ERR(d_tracer
))
1432 trace_create_file("uprobe_events", 0644, d_tracer
,
1433 NULL
, &uprobe_events_ops
);
1434 /* Profile interface */
1435 trace_create_file("uprobe_profile", 0444, d_tracer
,
1436 NULL
, &uprobe_profile_ops
);
1440 fs_initcall(init_uprobe_trace
);