2 * uprobes-based tracing events
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 * Copyright (C) IBM Corporation, 2010-2012
18 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
20 #define pr_fmt(fmt) "trace_kprobe: " fmt
22 #include <linux/module.h>
23 #include <linux/uaccess.h>
24 #include <linux/uprobes.h>
25 #include <linux/namei.h>
26 #include <linux/string.h>
27 #include <linux/rculist.h>
29 #include "trace_probe.h"
31 #define UPROBE_EVENT_SYSTEM "uprobes"
33 struct uprobe_trace_entry_head {
34 struct trace_entry ent;
35 unsigned long vaddr[];
38 #define SIZEOF_TRACE_ENTRY(is_return) \
39 (sizeof(struct uprobe_trace_entry_head) + \
40 sizeof(unsigned long) * (is_return ? 2 : 1))
42 #define DATAOF_TRACE_ENTRY(entry, is_return) \
43 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
45 struct trace_uprobe_filter {
48 struct list_head perf_events;
52 * uprobe event core functions
55 struct list_head list;
56 struct trace_uprobe_filter filter;
57 struct uprobe_consumer consumer;
63 struct trace_probe tp;
66 #define SIZEOF_TRACE_UPROBE(n) \
67 (offsetof(struct trace_uprobe, tp.args) + \
68 (sizeof(struct probe_arg) * (n)))
70 static int register_uprobe_event(struct trace_uprobe *tu);
71 static int unregister_uprobe_event(struct trace_uprobe *tu);
73 static DEFINE_MUTEX(uprobe_lock);
74 static LIST_HEAD(uprobe_list);
76 struct uprobe_dispatch_data {
77 struct trace_uprobe *tu;
78 unsigned long bp_addr;
81 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
82 static int uretprobe_dispatcher(struct uprobe_consumer *con,
83 unsigned long func, struct pt_regs *regs);
85 #ifdef CONFIG_STACK_GROWSUP
86 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
88 return addr - (n * sizeof(long));
91 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
93 return addr + (n * sizeof(long));
97 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
100 unsigned long addr = user_stack_pointer(regs);
102 addr = adjust_stack_addr(addr, n);
104 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
111 * Uprobes-specific fetch functions
113 #define DEFINE_FETCH_stack(type) \
114 static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
115 void *offset, void *dest) \
117 *(type *)dest = (type)get_user_stack_nth(regs, \
118 ((unsigned long)offset)); \
120 DEFINE_BASIC_FETCH_FUNCS(stack)
121 /* No string on the stack entry */
122 #define fetch_stack_string NULL
123 #define fetch_stack_string_size NULL
125 #define DEFINE_FETCH_memory(type) \
126 static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
127 void *addr, void *dest) \
130 void __user *vaddr = (void __force __user *) addr; \
132 if (copy_from_user(&retval, vaddr, sizeof(type))) \
135 *(type *) dest = retval; \
137 DEFINE_BASIC_FETCH_FUNCS(memory)
139 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
140 * length and relative data location.
142 static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
143 void *addr, void *dest)
146 u32 rloc = *(u32 *)dest;
147 int maxlen = get_rloc_len(rloc);
148 u8 *dst = get_rloc_data(dest);
149 void __user *src = (void __force __user *) addr;
154 ret = strncpy_from_user(dst, src, maxlen);
158 if (ret < 0) { /* Failed to fetch string */
159 ((u8 *)get_rloc_data(dest))[0] = '\0';
160 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
162 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
166 static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
167 void *addr, void *dest)
170 void __user *vaddr = (void __force __user *) addr;
172 len = strnlen_user(vaddr, MAX_STRING_SIZE);
174 if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */
180 static unsigned long translate_user_vaddr(void *file_offset)
182 unsigned long base_addr;
183 struct uprobe_dispatch_data *udd;
185 udd = (void *) current->utask->vaddr;
187 base_addr = udd->bp_addr - udd->tu->offset;
188 return base_addr + (unsigned long)file_offset;
191 #define DEFINE_FETCH_file_offset(type) \
192 static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \
193 void *offset, void *dest)\
195 void *vaddr = (void *)translate_user_vaddr(offset); \
197 FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
199 DEFINE_BASIC_FETCH_FUNCS(file_offset)
200 DEFINE_FETCH_file_offset(string)
201 DEFINE_FETCH_file_offset(string_size)
203 /* Fetch type information table */
204 static const struct fetch_type uprobes_fetch_type_table[] = {
206 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
207 sizeof(u32), 1, "__data_loc char[]"),
208 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
209 string_size, sizeof(u32), 0, "u32"),
211 ASSIGN_FETCH_TYPE(u8, u8, 0),
212 ASSIGN_FETCH_TYPE(u16, u16, 0),
213 ASSIGN_FETCH_TYPE(u32, u32, 0),
214 ASSIGN_FETCH_TYPE(u64, u64, 0),
215 ASSIGN_FETCH_TYPE(s8, u8, 1),
216 ASSIGN_FETCH_TYPE(s16, u16, 1),
217 ASSIGN_FETCH_TYPE(s32, u32, 1),
218 ASSIGN_FETCH_TYPE(s64, u64, 1),
219 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
220 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
221 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
222 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
224 ASSIGN_FETCH_TYPE_END
227 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
229 rwlock_init(&filter->rwlock);
230 filter->nr_systemwide = 0;
231 INIT_LIST_HEAD(&filter->perf_events);
234 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
236 return !filter->nr_systemwide && list_empty(&filter->perf_events);
239 static inline bool is_ret_probe(struct trace_uprobe *tu)
241 return tu->consumer.ret_handler != NULL;
245 * Allocate new trace_uprobe and initialize it (including uprobes).
247 static struct trace_uprobe *
248 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
250 struct trace_uprobe *tu;
252 if (!event || !is_good_name(event))
253 return ERR_PTR(-EINVAL);
255 if (!group || !is_good_name(group))
256 return ERR_PTR(-EINVAL);
258 tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
260 return ERR_PTR(-ENOMEM);
262 tu->tp.call.class = &tu->tp.class;
263 tu->tp.call.name = kstrdup(event, GFP_KERNEL);
264 if (!tu->tp.call.name)
267 tu->tp.class.system = kstrdup(group, GFP_KERNEL);
268 if (!tu->tp.class.system)
271 INIT_LIST_HEAD(&tu->list);
272 INIT_LIST_HEAD(&tu->tp.files);
273 tu->consumer.handler = uprobe_dispatcher;
275 tu->consumer.ret_handler = uretprobe_dispatcher;
276 init_trace_uprobe_filter(&tu->filter);
280 kfree(tu->tp.call.name);
283 return ERR_PTR(-ENOMEM);
286 static void free_trace_uprobe(struct trace_uprobe *tu)
290 for (i = 0; i < tu->tp.nr_args; i++)
291 traceprobe_free_probe_arg(&tu->tp.args[i]);
294 kfree(tu->tp.call.class->system);
295 kfree(tu->tp.call.name);
300 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
302 struct trace_uprobe *tu;
304 list_for_each_entry(tu, &uprobe_list, list)
305 if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
306 strcmp(tu->tp.call.class->system, group) == 0)
312 /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
313 static int unregister_trace_uprobe(struct trace_uprobe *tu)
317 ret = unregister_uprobe_event(tu);
322 free_trace_uprobe(tu);
326 /* Register a trace_uprobe and probe_event */
327 static int register_trace_uprobe(struct trace_uprobe *tu)
329 struct trace_uprobe *old_tu;
332 mutex_lock(&uprobe_lock);
334 /* register as an event */
335 old_tu = find_probe_event(trace_event_name(&tu->tp.call),
336 tu->tp.call.class->system);
338 /* delete old event */
339 ret = unregister_trace_uprobe(old_tu);
344 ret = register_uprobe_event(tu);
346 pr_warn("Failed to register probe event(%d)\n", ret);
350 list_add_tail(&tu->list, &uprobe_list);
353 mutex_unlock(&uprobe_lock);
360 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
362 * - Remove uprobe: -:[GRP/]EVENT
364 static int create_trace_uprobe(int argc, char **argv)
366 struct trace_uprobe *tu;
367 char *arg, *event, *group, *filename;
368 char buf[MAX_EVENT_NAME_LEN];
370 unsigned long offset;
371 bool is_delete, is_return;
380 /* argc must be >= 1 */
381 if (argv[0][0] == '-')
383 else if (argv[0][0] == 'r')
385 else if (argv[0][0] != 'p') {
386 pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
390 if (argv[0][1] == ':') {
392 arg = strchr(event, '/');
399 if (strlen(group) == 0) {
400 pr_info("Group name is not specified\n");
404 if (strlen(event) == 0) {
405 pr_info("Event name is not specified\n");
410 group = UPROBE_EVENT_SYSTEM;
416 pr_info("Delete command needs an event name.\n");
419 mutex_lock(&uprobe_lock);
420 tu = find_probe_event(event, group);
423 mutex_unlock(&uprobe_lock);
424 pr_info("Event %s/%s doesn't exist.\n", group, event);
427 /* delete an event */
428 ret = unregister_trace_uprobe(tu);
429 mutex_unlock(&uprobe_lock);
434 pr_info("Probe point is not specified.\n");
437 /* Find the last occurrence, in case the path contains ':' too. */
438 arg = strrchr(argv[1], ':');
444 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
448 if (!d_is_reg(path.dentry)) {
450 goto fail_address_parse;
453 ret = kstrtoul(arg, 0, &offset);
455 goto fail_address_parse;
465 tail = kstrdup(kbasename(filename), GFP_KERNEL);
468 goto fail_address_parse;
471 ptr = strpbrk(tail, ".-_");
475 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
480 tu = alloc_trace_uprobe(group, event, argc, is_return);
482 pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
484 goto fail_address_parse;
488 tu->filename = kstrdup(filename, GFP_KERNEL);
491 pr_info("Failed to allocate filename.\n");
496 /* parse arguments */
498 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
499 struct probe_arg *parg = &tu->tp.args[i];
501 /* Increment count for freeing args in error case */
504 /* Parse argument name */
505 arg = strchr(argv[i], '=');
508 parg->name = kstrdup(argv[i], GFP_KERNEL);
511 /* If argument name is omitted, set "argN" */
512 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
513 parg->name = kstrdup(buf, GFP_KERNEL);
517 pr_info("Failed to allocate argument[%d] name.\n", i);
522 if (!is_good_name(parg->name)) {
523 pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
528 if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
529 pr_info("Argument[%d] name '%s' conflicts with "
530 "another field.\n", i, argv[i]);
535 /* Parse fetch argument */
536 ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
538 uprobes_fetch_type_table);
540 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
545 ret = register_trace_uprobe(tu);
551 free_trace_uprobe(tu);
557 pr_info("Failed to parse address or file.\n");
562 static int cleanup_all_probes(void)
564 struct trace_uprobe *tu;
567 mutex_lock(&uprobe_lock);
568 while (!list_empty(&uprobe_list)) {
569 tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
570 ret = unregister_trace_uprobe(tu);
574 mutex_unlock(&uprobe_lock);
578 /* Probes listing interfaces */
579 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
581 mutex_lock(&uprobe_lock);
582 return seq_list_start(&uprobe_list, *pos);
585 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
587 return seq_list_next(v, &uprobe_list, pos);
590 static void probes_seq_stop(struct seq_file *m, void *v)
592 mutex_unlock(&uprobe_lock);
595 static int probes_seq_show(struct seq_file *m, void *v)
597 struct trace_uprobe *tu = v;
598 char c = is_ret_probe(tu) ? 'r' : 'p';
601 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, tu->tp.call.class->system,
602 trace_event_name(&tu->tp.call), tu->filename,
603 (int)(sizeof(void *) * 2), tu->offset);
605 for (i = 0; i < tu->tp.nr_args; i++)
606 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
612 static const struct seq_operations probes_seq_op = {
613 .start = probes_seq_start,
614 .next = probes_seq_next,
615 .stop = probes_seq_stop,
616 .show = probes_seq_show
619 static int probes_open(struct inode *inode, struct file *file)
623 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
624 ret = cleanup_all_probes();
629 return seq_open(file, &probes_seq_op);
632 static ssize_t probes_write(struct file *file, const char __user *buffer,
633 size_t count, loff_t *ppos)
635 return trace_parse_run_command(file, buffer, count, ppos, create_trace_uprobe);
638 static const struct file_operations uprobe_events_ops = {
639 .owner = THIS_MODULE,
643 .release = seq_release,
644 .write = probes_write,
647 /* Probes profiling interfaces */
648 static int probes_profile_seq_show(struct seq_file *m, void *v)
650 struct trace_uprobe *tu = v;
652 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
653 trace_event_name(&tu->tp.call), tu->nhit);
657 static const struct seq_operations profile_seq_op = {
658 .start = probes_seq_start,
659 .next = probes_seq_next,
660 .stop = probes_seq_stop,
661 .show = probes_profile_seq_show
664 static int profile_open(struct inode *inode, struct file *file)
666 return seq_open(file, &profile_seq_op);
669 static const struct file_operations uprobe_profile_ops = {
670 .owner = THIS_MODULE,
671 .open = profile_open,
674 .release = seq_release,
677 struct uprobe_cpu_buffer {
681 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
682 static int uprobe_buffer_refcnt;
684 static int uprobe_buffer_init(void)
688 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
689 if (uprobe_cpu_buffer == NULL)
692 for_each_possible_cpu(cpu) {
693 struct page *p = alloc_pages_node(cpu_to_node(cpu),
699 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
700 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
706 for_each_possible_cpu(cpu) {
709 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
712 free_percpu(uprobe_cpu_buffer);
716 static int uprobe_buffer_enable(void)
720 BUG_ON(!mutex_is_locked(&event_mutex));
722 if (uprobe_buffer_refcnt++ == 0) {
723 ret = uprobe_buffer_init();
725 uprobe_buffer_refcnt--;
731 static void uprobe_buffer_disable(void)
735 BUG_ON(!mutex_is_locked(&event_mutex));
737 if (--uprobe_buffer_refcnt == 0) {
738 for_each_possible_cpu(cpu)
739 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
742 free_percpu(uprobe_cpu_buffer);
743 uprobe_cpu_buffer = NULL;
747 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
749 struct uprobe_cpu_buffer *ucb;
752 cpu = raw_smp_processor_id();
753 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
756 * Use per-cpu buffers for fastest access, but we might migrate
757 * so the mutex makes sure we have sole access to it.
759 mutex_lock(&ucb->mutex);
764 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
766 mutex_unlock(&ucb->mutex);
769 static void __uprobe_trace_func(struct trace_uprobe *tu,
770 unsigned long func, struct pt_regs *regs,
771 struct uprobe_cpu_buffer *ucb, int dsize,
772 struct trace_event_file *trace_file)
774 struct uprobe_trace_entry_head *entry;
775 struct ring_buffer_event *event;
776 struct ring_buffer *buffer;
779 struct trace_event_call *call = &tu->tp.call;
781 WARN_ON(call != trace_file->event_call);
783 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
786 if (trace_trigger_soft_disabled(trace_file))
789 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
790 size = esize + tu->tp.size + dsize;
791 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
792 call->event.type, size, 0, 0);
796 entry = ring_buffer_event_data(event);
797 if (is_ret_probe(tu)) {
798 entry->vaddr[0] = func;
799 entry->vaddr[1] = instruction_pointer(regs);
800 data = DATAOF_TRACE_ENTRY(entry, true);
802 entry->vaddr[0] = instruction_pointer(regs);
803 data = DATAOF_TRACE_ENTRY(entry, false);
806 memcpy(data, ucb->buf, tu->tp.size + dsize);
808 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
812 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
813 struct uprobe_cpu_buffer *ucb, int dsize)
815 struct event_file_link *link;
817 if (is_ret_probe(tu))
821 list_for_each_entry_rcu(link, &tu->tp.files, list)
822 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
828 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
829 struct pt_regs *regs,
830 struct uprobe_cpu_buffer *ucb, int dsize)
832 struct event_file_link *link;
835 list_for_each_entry_rcu(link, &tu->tp.files, list)
836 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
840 /* Event entry printers */
841 static enum print_line_t
842 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
844 struct uprobe_trace_entry_head *entry;
845 struct trace_seq *s = &iter->seq;
846 struct trace_uprobe *tu;
850 entry = (struct uprobe_trace_entry_head *)iter->ent;
851 tu = container_of(event, struct trace_uprobe, tp.call.event);
853 if (is_ret_probe(tu)) {
854 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
855 trace_event_name(&tu->tp.call),
856 entry->vaddr[1], entry->vaddr[0]);
857 data = DATAOF_TRACE_ENTRY(entry, true);
859 trace_seq_printf(s, "%s: (0x%lx)",
860 trace_event_name(&tu->tp.call),
862 data = DATAOF_TRACE_ENTRY(entry, false);
865 for (i = 0; i < tu->tp.nr_args; i++) {
866 struct probe_arg *parg = &tu->tp.args[i];
868 if (!parg->type->print(s, parg->name, data + parg->offset, entry))
872 trace_seq_putc(s, '\n');
875 return trace_handle_return(s);
878 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
879 enum uprobe_filter_ctx ctx,
880 struct mm_struct *mm);
883 probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
884 filter_func_t filter)
886 bool enabled = trace_probe_is_enabled(&tu->tp);
887 struct event_file_link *link = NULL;
891 if (tu->tp.flags & TP_FLAG_PROFILE)
894 link = kmalloc(sizeof(*link), GFP_KERNEL);
899 list_add_tail_rcu(&link->list, &tu->tp.files);
901 tu->tp.flags |= TP_FLAG_TRACE;
903 if (tu->tp.flags & TP_FLAG_TRACE)
906 tu->tp.flags |= TP_FLAG_PROFILE;
909 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
914 ret = uprobe_buffer_enable();
918 tu->consumer.filter = filter;
919 tu->inode = d_real_inode(tu->path.dentry);
920 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
927 uprobe_buffer_disable();
931 list_del(&link->list);
933 tu->tp.flags &= ~TP_FLAG_TRACE;
935 tu->tp.flags &= ~TP_FLAG_PROFILE;
941 probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
943 if (!trace_probe_is_enabled(&tu->tp))
947 struct event_file_link *link;
949 link = find_event_file_link(&tu->tp, file);
953 list_del_rcu(&link->list);
954 /* synchronize with u{,ret}probe_trace_func */
958 if (!list_empty(&tu->tp.files))
962 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
964 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
966 tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
968 uprobe_buffer_disable();
971 static int uprobe_event_define_fields(struct trace_event_call *event_call)
974 struct uprobe_trace_entry_head field;
975 struct trace_uprobe *tu = event_call->data;
977 if (is_ret_probe(tu)) {
978 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
979 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
980 size = SIZEOF_TRACE_ENTRY(true);
982 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
983 size = SIZEOF_TRACE_ENTRY(false);
985 /* Set argument names as fields */
986 for (i = 0; i < tu->tp.nr_args; i++) {
987 struct probe_arg *parg = &tu->tp.args[i];
989 ret = trace_define_field(event_call, parg->type->fmttype,
990 parg->name, size + parg->offset,
991 parg->type->size, parg->type->is_signed,
1000 #ifdef CONFIG_PERF_EVENTS
1002 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1004 struct perf_event *event;
1006 if (filter->nr_systemwide)
1009 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1010 if (event->hw.target->mm == mm)
1018 uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1020 return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
1023 static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1027 write_lock(&tu->filter.rwlock);
1028 if (event->hw.target) {
1029 list_del(&event->hw.tp_list);
1030 done = tu->filter.nr_systemwide ||
1031 (event->hw.target->flags & PF_EXITING) ||
1032 uprobe_filter_event(tu, event);
1034 tu->filter.nr_systemwide--;
1035 done = tu->filter.nr_systemwide;
1037 write_unlock(&tu->filter.rwlock);
1040 return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1045 static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1050 write_lock(&tu->filter.rwlock);
1051 if (event->hw.target) {
1053 * event->parent != NULL means copy_process(), we can avoid
1054 * uprobe_apply(). current->mm must be probed and we can rely
1055 * on dup_mmap() which preserves the already installed bp's.
1057 * attr.enable_on_exec means that exec/mmap will install the
1058 * breakpoints we need.
1060 done = tu->filter.nr_systemwide ||
1061 event->parent || event->attr.enable_on_exec ||
1062 uprobe_filter_event(tu, event);
1063 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1065 done = tu->filter.nr_systemwide;
1066 tu->filter.nr_systemwide++;
1068 write_unlock(&tu->filter.rwlock);
1072 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1074 uprobe_perf_close(tu, event);
1079 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1080 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1082 struct trace_uprobe *tu;
1085 tu = container_of(uc, struct trace_uprobe, consumer);
1086 read_lock(&tu->filter.rwlock);
1087 ret = __uprobe_perf_filter(&tu->filter, mm);
1088 read_unlock(&tu->filter.rwlock);
1093 static void __uprobe_perf_func(struct trace_uprobe *tu,
1094 unsigned long func, struct pt_regs *regs,
1095 struct uprobe_cpu_buffer *ucb, int dsize)
1097 struct trace_event_call *call = &tu->tp.call;
1098 struct uprobe_trace_entry_head *entry;
1099 struct hlist_head *head;
1104 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1107 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1109 size = esize + tu->tp.size + dsize;
1110 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1111 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1115 head = this_cpu_ptr(call->perf_events);
1116 if (hlist_empty(head))
1119 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1123 if (is_ret_probe(tu)) {
1124 entry->vaddr[0] = func;
1125 entry->vaddr[1] = instruction_pointer(regs);
1126 data = DATAOF_TRACE_ENTRY(entry, true);
1128 entry->vaddr[0] = instruction_pointer(regs);
1129 data = DATAOF_TRACE_ENTRY(entry, false);
1132 memcpy(data, ucb->buf, tu->tp.size + dsize);
1134 if (size - esize > tu->tp.size + dsize) {
1135 int len = tu->tp.size + dsize;
1137 memset(data + len, 0, size - esize - len);
1140 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1146 /* uprobe profile handler */
1147 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1148 struct uprobe_cpu_buffer *ucb, int dsize)
1150 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1151 return UPROBE_HANDLER_REMOVE;
1153 if (!is_ret_probe(tu))
1154 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1158 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1159 struct pt_regs *regs,
1160 struct uprobe_cpu_buffer *ucb, int dsize)
1162 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1165 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1166 const char **filename, u64 *probe_offset,
1167 bool perf_type_tracepoint)
1169 const char *pevent = trace_event_name(event->tp_event);
1170 const char *group = event->tp_event->class->system;
1171 struct trace_uprobe *tu;
1173 if (perf_type_tracepoint)
1174 tu = find_probe_event(pevent, group);
1176 tu = event->tp_event->data;
1180 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1181 : BPF_FD_TYPE_UPROBE;
1182 *filename = tu->filename;
1183 *probe_offset = tu->offset;
1186 #endif /* CONFIG_PERF_EVENTS */
1189 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1192 struct trace_uprobe *tu = event->data;
1193 struct trace_event_file *file = data;
1196 case TRACE_REG_REGISTER:
1197 return probe_event_enable(tu, file, NULL);
1199 case TRACE_REG_UNREGISTER:
1200 probe_event_disable(tu, file);
1203 #ifdef CONFIG_PERF_EVENTS
1204 case TRACE_REG_PERF_REGISTER:
1205 return probe_event_enable(tu, NULL, uprobe_perf_filter);
1207 case TRACE_REG_PERF_UNREGISTER:
1208 probe_event_disable(tu, NULL);
1211 case TRACE_REG_PERF_OPEN:
1212 return uprobe_perf_open(tu, data);
1214 case TRACE_REG_PERF_CLOSE:
1215 return uprobe_perf_close(tu, data);
1224 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1226 struct trace_uprobe *tu;
1227 struct uprobe_dispatch_data udd;
1228 struct uprobe_cpu_buffer *ucb;
1233 tu = container_of(con, struct trace_uprobe, consumer);
1237 udd.bp_addr = instruction_pointer(regs);
1239 current->utask->vaddr = (unsigned long) &udd;
1241 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1244 dsize = __get_data_size(&tu->tp, regs);
1245 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1247 ucb = uprobe_buffer_get();
1248 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1250 if (tu->tp.flags & TP_FLAG_TRACE)
1251 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1253 #ifdef CONFIG_PERF_EVENTS
1254 if (tu->tp.flags & TP_FLAG_PROFILE)
1255 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1257 uprobe_buffer_put(ucb);
1261 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1262 unsigned long func, struct pt_regs *regs)
1264 struct trace_uprobe *tu;
1265 struct uprobe_dispatch_data udd;
1266 struct uprobe_cpu_buffer *ucb;
1269 tu = container_of(con, struct trace_uprobe, consumer);
1274 current->utask->vaddr = (unsigned long) &udd;
1276 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1279 dsize = __get_data_size(&tu->tp, regs);
1280 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1282 ucb = uprobe_buffer_get();
1283 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1285 if (tu->tp.flags & TP_FLAG_TRACE)
1286 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1288 #ifdef CONFIG_PERF_EVENTS
1289 if (tu->tp.flags & TP_FLAG_PROFILE)
1290 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1292 uprobe_buffer_put(ucb);
1296 static struct trace_event_functions uprobe_funcs = {
1297 .trace = print_uprobe_event
1300 static inline void init_trace_event_call(struct trace_uprobe *tu,
1301 struct trace_event_call *call)
1303 INIT_LIST_HEAD(&call->class->fields);
1304 call->event.funcs = &uprobe_funcs;
1305 call->class->define_fields = uprobe_event_define_fields;
1307 call->flags = TRACE_EVENT_FL_UPROBE;
1308 call->class->reg = trace_uprobe_register;
1312 static int register_uprobe_event(struct trace_uprobe *tu)
1314 struct trace_event_call *call = &tu->tp.call;
1317 init_trace_event_call(tu, call);
1319 if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
1322 ret = register_trace_event(&call->event);
1324 kfree(call->print_fmt);
1328 ret = trace_add_event_call(call);
1331 pr_info("Failed to register uprobe event: %s\n",
1332 trace_event_name(call));
1333 kfree(call->print_fmt);
1334 unregister_trace_event(&call->event);
1340 static int unregister_uprobe_event(struct trace_uprobe *tu)
1344 /* tu->event is unregistered in trace_remove_event_call() */
1345 ret = trace_remove_event_call(&tu->tp.call);
1348 kfree(tu->tp.call.print_fmt);
1349 tu->tp.call.print_fmt = NULL;
1353 #ifdef CONFIG_PERF_EVENTS
1354 struct trace_event_call *
1355 create_local_trace_uprobe(char *name, unsigned long offs, bool is_return)
1357 struct trace_uprobe *tu;
1361 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1363 return ERR_PTR(ret);
1365 if (!d_is_reg(path.dentry)) {
1367 return ERR_PTR(-EINVAL);
1371 * local trace_kprobes are not added to probe_list, so they are never
1372 * searched in find_trace_kprobe(). Therefore, there is no concern of
1373 * duplicated name "DUMMY_EVENT" here.
1375 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1379 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1382 return ERR_CAST(tu);
1387 tu->filename = kstrdup(name, GFP_KERNEL);
1388 init_trace_event_call(tu, &tu->tp.call);
1390 if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1395 return &tu->tp.call;
1397 free_trace_uprobe(tu);
1398 return ERR_PTR(ret);
1401 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1403 struct trace_uprobe *tu;
1405 tu = container_of(event_call, struct trace_uprobe, tp.call);
1407 kfree(tu->tp.call.print_fmt);
1408 tu->tp.call.print_fmt = NULL;
1410 free_trace_uprobe(tu);
1412 #endif /* CONFIG_PERF_EVENTS */
1414 /* Make a trace interface for controling probe points */
1415 static __init int init_uprobe_trace(void)
1417 struct dentry *d_tracer;
1419 d_tracer = tracing_init_dentry();
1420 if (IS_ERR(d_tracer))
1423 trace_create_file("uprobe_events", 0644, d_tracer,
1424 NULL, &uprobe_events_ops);
1425 /* Profile interface */
1426 trace_create_file("uprobe_profile", 0444, d_tracer,
1427 NULL, &uprobe_profile_ops);
1431 fs_initcall(init_uprobe_trace);