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);