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>
21 #include <linux/module.h>
22 #include <linux/uaccess.h>
23 #include <linux/uprobes.h>
24 #include <linux/namei.h>
25 #include <linux/string.h>
27 #include "trace_probe.h"
29 #define UPROBE_EVENT_SYSTEM "uprobes"
31 struct uprobe_trace_entry_head {
32 struct trace_entry ent;
33 unsigned long vaddr[];
36 #define SIZEOF_TRACE_ENTRY(is_return) \
37 (sizeof(struct uprobe_trace_entry_head) + \
38 sizeof(unsigned long) * (is_return ? 2 : 1))
40 #define DATAOF_TRACE_ENTRY(entry, is_return) \
41 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
43 struct trace_uprobe_filter {
46 struct list_head perf_events;
50 * uprobe event core functions
53 struct list_head list;
54 struct trace_uprobe_filter filter;
55 struct uprobe_consumer consumer;
60 struct trace_probe tp;
63 #define SIZEOF_TRACE_UPROBE(n) \
64 (offsetof(struct trace_uprobe, tp.args) + \
65 (sizeof(struct probe_arg) * (n)))
67 static int register_uprobe_event(struct trace_uprobe *tu);
68 static int unregister_uprobe_event(struct trace_uprobe *tu);
70 static DEFINE_MUTEX(uprobe_lock);
71 static LIST_HEAD(uprobe_list);
73 struct uprobe_dispatch_data {
74 struct trace_uprobe *tu;
75 unsigned long bp_addr;
78 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
79 static int uretprobe_dispatcher(struct uprobe_consumer *con,
80 unsigned long func, struct pt_regs *regs);
82 #ifdef CONFIG_STACK_GROWSUP
83 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
85 return addr - (n * sizeof(long));
88 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
90 return addr + (n * sizeof(long));
94 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
97 unsigned long addr = user_stack_pointer(regs);
99 addr = adjust_stack_addr(addr, n);
101 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
108 * Uprobes-specific fetch functions
110 #define DEFINE_FETCH_stack(type) \
111 static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
112 void *offset, void *dest) \
114 *(type *)dest = (type)get_user_stack_nth(regs, \
115 ((unsigned long)offset)); \
117 DEFINE_BASIC_FETCH_FUNCS(stack)
118 /* No string on the stack entry */
119 #define fetch_stack_string NULL
120 #define fetch_stack_string_size NULL
122 #define DEFINE_FETCH_memory(type) \
123 static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
124 void *addr, void *dest) \
127 void __user *vaddr = (void __force __user *) addr; \
129 if (copy_from_user(&retval, vaddr, sizeof(type))) \
132 *(type *) dest = retval; \
134 DEFINE_BASIC_FETCH_FUNCS(memory)
136 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
137 * length and relative data location.
139 static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
140 void *addr, void *dest)
143 u32 rloc = *(u32 *)dest;
144 int maxlen = get_rloc_len(rloc);
145 u8 *dst = get_rloc_data(dest);
146 void __user *src = (void __force __user *) addr;
151 ret = strncpy_from_user(dst, src, maxlen);
153 if (ret < 0) { /* Failed to fetch string */
154 ((u8 *)get_rloc_data(dest))[0] = '\0';
155 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
157 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
161 static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
162 void *addr, void *dest)
165 void __user *vaddr = (void __force __user *) addr;
167 len = strnlen_user(vaddr, MAX_STRING_SIZE);
169 if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */
175 static unsigned long translate_user_vaddr(void *file_offset)
177 unsigned long base_addr;
178 struct uprobe_dispatch_data *udd;
180 udd = (void *) current->utask->vaddr;
182 base_addr = udd->bp_addr - udd->tu->offset;
183 return base_addr + (unsigned long)file_offset;
186 #define DEFINE_FETCH_file_offset(type) \
187 static __kprobes void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs,\
188 void *offset, void *dest) \
190 void *vaddr = (void *)translate_user_vaddr(offset); \
192 FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
194 DEFINE_BASIC_FETCH_FUNCS(file_offset)
195 DEFINE_FETCH_file_offset(string)
196 DEFINE_FETCH_file_offset(string_size)
198 /* Fetch type information table */
199 const struct fetch_type uprobes_fetch_type_table[] = {
201 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
202 sizeof(u32), 1, "__data_loc char[]"),
203 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
204 string_size, sizeof(u32), 0, "u32"),
206 ASSIGN_FETCH_TYPE(u8, u8, 0),
207 ASSIGN_FETCH_TYPE(u16, u16, 0),
208 ASSIGN_FETCH_TYPE(u32, u32, 0),
209 ASSIGN_FETCH_TYPE(u64, u64, 0),
210 ASSIGN_FETCH_TYPE(s8, u8, 1),
211 ASSIGN_FETCH_TYPE(s16, u16, 1),
212 ASSIGN_FETCH_TYPE(s32, u32, 1),
213 ASSIGN_FETCH_TYPE(s64, u64, 1),
215 ASSIGN_FETCH_TYPE_END
218 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
220 rwlock_init(&filter->rwlock);
221 filter->nr_systemwide = 0;
222 INIT_LIST_HEAD(&filter->perf_events);
225 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
227 return !filter->nr_systemwide && list_empty(&filter->perf_events);
230 static inline bool is_ret_probe(struct trace_uprobe *tu)
232 return tu->consumer.ret_handler != NULL;
236 * Allocate new trace_uprobe and initialize it (including uprobes).
238 static struct trace_uprobe *
239 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
241 struct trace_uprobe *tu;
243 if (!event || !is_good_name(event))
244 return ERR_PTR(-EINVAL);
246 if (!group || !is_good_name(group))
247 return ERR_PTR(-EINVAL);
249 tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
251 return ERR_PTR(-ENOMEM);
253 tu->tp.call.class = &tu->tp.class;
254 tu->tp.call.name = kstrdup(event, GFP_KERNEL);
255 if (!tu->tp.call.name)
258 tu->tp.class.system = kstrdup(group, GFP_KERNEL);
259 if (!tu->tp.class.system)
262 INIT_LIST_HEAD(&tu->list);
263 INIT_LIST_HEAD(&tu->tp.files);
264 tu->consumer.handler = uprobe_dispatcher;
266 tu->consumer.ret_handler = uretprobe_dispatcher;
267 init_trace_uprobe_filter(&tu->filter);
268 tu->tp.call.flags |= TRACE_EVENT_FL_USE_CALL_FILTER;
272 kfree(tu->tp.call.name);
275 return ERR_PTR(-ENOMEM);
278 static void free_trace_uprobe(struct trace_uprobe *tu)
282 for (i = 0; i < tu->tp.nr_args; i++)
283 traceprobe_free_probe_arg(&tu->tp.args[i]);
286 kfree(tu->tp.call.class->system);
287 kfree(tu->tp.call.name);
292 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
294 struct trace_uprobe *tu;
296 list_for_each_entry(tu, &uprobe_list, list)
297 if (strcmp(ftrace_event_name(&tu->tp.call), event) == 0 &&
298 strcmp(tu->tp.call.class->system, group) == 0)
304 /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
305 static int unregister_trace_uprobe(struct trace_uprobe *tu)
309 ret = unregister_uprobe_event(tu);
314 free_trace_uprobe(tu);
318 /* Register a trace_uprobe and probe_event */
319 static int register_trace_uprobe(struct trace_uprobe *tu)
321 struct trace_uprobe *old_tu;
324 mutex_lock(&uprobe_lock);
326 /* register as an event */
327 old_tu = find_probe_event(ftrace_event_name(&tu->tp.call),
328 tu->tp.call.class->system);
330 /* delete old event */
331 ret = unregister_trace_uprobe(old_tu);
336 ret = register_uprobe_event(tu);
338 pr_warning("Failed to register probe event(%d)\n", ret);
342 list_add_tail(&tu->list, &uprobe_list);
345 mutex_unlock(&uprobe_lock);
352 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
354 * - Remove uprobe: -:[GRP/]EVENT
356 static int create_trace_uprobe(int argc, char **argv)
358 struct trace_uprobe *tu;
360 char *arg, *event, *group, *filename;
361 char buf[MAX_EVENT_NAME_LEN];
363 unsigned long offset;
364 bool is_delete, is_return;
374 /* argc must be >= 1 */
375 if (argv[0][0] == '-')
377 else if (argv[0][0] == 'r')
379 else if (argv[0][0] != 'p') {
380 pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
384 if (argv[0][1] == ':') {
386 arg = strchr(event, '/');
393 if (strlen(group) == 0) {
394 pr_info("Group name is not specified\n");
398 if (strlen(event) == 0) {
399 pr_info("Event name is not specified\n");
404 group = UPROBE_EVENT_SYSTEM;
410 pr_info("Delete command needs an event name.\n");
413 mutex_lock(&uprobe_lock);
414 tu = find_probe_event(event, group);
417 mutex_unlock(&uprobe_lock);
418 pr_info("Event %s/%s doesn't exist.\n", group, event);
421 /* delete an event */
422 ret = unregister_trace_uprobe(tu);
423 mutex_unlock(&uprobe_lock);
428 pr_info("Probe point is not specified.\n");
431 if (isdigit(argv[1][0])) {
432 pr_info("probe point must be have a filename.\n");
435 arg = strchr(argv[1], ':');
438 goto fail_address_parse;
443 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
445 goto fail_address_parse;
447 inode = igrab(path.dentry->d_inode);
450 if (!inode || !S_ISREG(inode->i_mode)) {
452 goto fail_address_parse;
455 ret = kstrtoul(arg, 0, &offset);
457 goto fail_address_parse;
467 tail = kstrdup(kbasename(filename), GFP_KERNEL);
470 goto fail_address_parse;
473 ptr = strpbrk(tail, ".-_");
477 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
482 tu = alloc_trace_uprobe(group, event, argc, is_return);
484 pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
486 goto fail_address_parse;
490 tu->filename = kstrdup(filename, GFP_KERNEL);
493 pr_info("Failed to allocate filename.\n");
498 /* parse arguments */
500 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
501 struct probe_arg *parg = &tu->tp.args[i];
503 /* Increment count for freeing args in error case */
506 /* Parse argument name */
507 arg = strchr(argv[i], '=');
510 parg->name = kstrdup(argv[i], GFP_KERNEL);
513 /* If argument name is omitted, set "argN" */
514 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
515 parg->name = kstrdup(buf, GFP_KERNEL);
519 pr_info("Failed to allocate argument[%d] name.\n", i);
524 if (!is_good_name(parg->name)) {
525 pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
530 if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
531 pr_info("Argument[%d] name '%s' conflicts with "
532 "another field.\n", i, argv[i]);
537 /* Parse fetch argument */
538 ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
541 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
546 ret = register_trace_uprobe(tu);
552 free_trace_uprobe(tu);
559 pr_info("Failed to parse address or file.\n");
564 static int cleanup_all_probes(void)
566 struct trace_uprobe *tu;
569 mutex_lock(&uprobe_lock);
570 while (!list_empty(&uprobe_list)) {
571 tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
572 ret = unregister_trace_uprobe(tu);
576 mutex_unlock(&uprobe_lock);
580 /* Probes listing interfaces */
581 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
583 mutex_lock(&uprobe_lock);
584 return seq_list_start(&uprobe_list, *pos);
587 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
589 return seq_list_next(v, &uprobe_list, pos);
592 static void probes_seq_stop(struct seq_file *m, void *v)
594 mutex_unlock(&uprobe_lock);
597 static int probes_seq_show(struct seq_file *m, void *v)
599 struct trace_uprobe *tu = v;
600 char c = is_ret_probe(tu) ? 'r' : 'p';
603 seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system,
604 ftrace_event_name(&tu->tp.call));
605 seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset);
607 for (i = 0; i < tu->tp.nr_args; i++)
608 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
614 static const struct seq_operations probes_seq_op = {
615 .start = probes_seq_start,
616 .next = probes_seq_next,
617 .stop = probes_seq_stop,
618 .show = probes_seq_show
621 static int probes_open(struct inode *inode, struct file *file)
625 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
626 ret = cleanup_all_probes();
631 return seq_open(file, &probes_seq_op);
634 static ssize_t probes_write(struct file *file, const char __user *buffer,
635 size_t count, loff_t *ppos)
637 return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
640 static const struct file_operations uprobe_events_ops = {
641 .owner = THIS_MODULE,
645 .release = seq_release,
646 .write = probes_write,
649 /* Probes profiling interfaces */
650 static int probes_profile_seq_show(struct seq_file *m, void *v)
652 struct trace_uprobe *tu = v;
654 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
655 ftrace_event_name(&tu->tp.call), tu->nhit);
659 static const struct seq_operations profile_seq_op = {
660 .start = probes_seq_start,
661 .next = probes_seq_next,
662 .stop = probes_seq_stop,
663 .show = probes_profile_seq_show
666 static int profile_open(struct inode *inode, struct file *file)
668 return seq_open(file, &profile_seq_op);
671 static const struct file_operations uprobe_profile_ops = {
672 .owner = THIS_MODULE,
673 .open = profile_open,
676 .release = seq_release,
679 struct uprobe_cpu_buffer {
683 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
684 static int uprobe_buffer_refcnt;
686 static int uprobe_buffer_init(void)
690 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
691 if (uprobe_cpu_buffer == NULL)
694 for_each_possible_cpu(cpu) {
695 struct page *p = alloc_pages_node(cpu_to_node(cpu),
701 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
702 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
708 for_each_possible_cpu(cpu) {
711 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
714 free_percpu(uprobe_cpu_buffer);
718 static int uprobe_buffer_enable(void)
722 BUG_ON(!mutex_is_locked(&event_mutex));
724 if (uprobe_buffer_refcnt++ == 0) {
725 ret = uprobe_buffer_init();
727 uprobe_buffer_refcnt--;
733 static void uprobe_buffer_disable(void)
735 BUG_ON(!mutex_is_locked(&event_mutex));
737 if (--uprobe_buffer_refcnt == 0) {
738 free_percpu(uprobe_cpu_buffer);
739 uprobe_cpu_buffer = NULL;
743 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
745 struct uprobe_cpu_buffer *ucb;
748 cpu = raw_smp_processor_id();
749 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
752 * Use per-cpu buffers for fastest access, but we might migrate
753 * so the mutex makes sure we have sole access to it.
755 mutex_lock(&ucb->mutex);
760 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
762 mutex_unlock(&ucb->mutex);
765 static void __uprobe_trace_func(struct trace_uprobe *tu,
766 unsigned long func, struct pt_regs *regs,
767 struct uprobe_cpu_buffer *ucb, int dsize,
768 struct ftrace_event_file *ftrace_file)
770 struct uprobe_trace_entry_head *entry;
771 struct ring_buffer_event *event;
772 struct ring_buffer *buffer;
775 struct ftrace_event_call *call = &tu->tp.call;
777 WARN_ON(call != ftrace_file->event_call);
779 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
782 if (ftrace_trigger_soft_disabled(ftrace_file))
785 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
786 size = esize + tu->tp.size + dsize;
787 event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
788 call->event.type, size, 0, 0);
792 entry = ring_buffer_event_data(event);
793 if (is_ret_probe(tu)) {
794 entry->vaddr[0] = func;
795 entry->vaddr[1] = instruction_pointer(regs);
796 data = DATAOF_TRACE_ENTRY(entry, true);
798 entry->vaddr[0] = instruction_pointer(regs);
799 data = DATAOF_TRACE_ENTRY(entry, false);
802 memcpy(data, ucb->buf, tu->tp.size + dsize);
804 event_trigger_unlock_commit(ftrace_file, buffer, event, entry, 0, 0);
808 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
809 struct uprobe_cpu_buffer *ucb, int dsize)
811 struct event_file_link *link;
813 if (is_ret_probe(tu))
817 list_for_each_entry_rcu(link, &tu->tp.files, list)
818 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
824 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
825 struct pt_regs *regs,
826 struct uprobe_cpu_buffer *ucb, int dsize)
828 struct event_file_link *link;
831 list_for_each_entry_rcu(link, &tu->tp.files, list)
832 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
836 /* Event entry printers */
837 static enum print_line_t
838 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
840 struct uprobe_trace_entry_head *entry;
841 struct trace_seq *s = &iter->seq;
842 struct trace_uprobe *tu;
846 entry = (struct uprobe_trace_entry_head *)iter->ent;
847 tu = container_of(event, struct trace_uprobe, tp.call.event);
849 if (is_ret_probe(tu)) {
850 if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
851 ftrace_event_name(&tu->tp.call),
852 entry->vaddr[1], entry->vaddr[0]))
854 data = DATAOF_TRACE_ENTRY(entry, true);
856 if (!trace_seq_printf(s, "%s: (0x%lx)",
857 ftrace_event_name(&tu->tp.call),
860 data = DATAOF_TRACE_ENTRY(entry, false);
863 for (i = 0; i < tu->tp.nr_args; i++) {
864 struct probe_arg *parg = &tu->tp.args[i];
866 if (!parg->type->print(s, parg->name, data + parg->offset, entry))
870 if (trace_seq_puts(s, "\n"))
871 return TRACE_TYPE_HANDLED;
874 return TRACE_TYPE_PARTIAL_LINE;
877 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
878 enum uprobe_filter_ctx ctx,
879 struct mm_struct *mm);
882 probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
883 filter_func_t filter)
885 bool enabled = trace_probe_is_enabled(&tu->tp);
886 struct event_file_link *link = NULL;
890 link = kmalloc(sizeof(*link), GFP_KERNEL);
895 list_add_tail_rcu(&link->list, &tu->tp.files);
897 tu->tp.flags |= TP_FLAG_TRACE;
899 tu->tp.flags |= TP_FLAG_PROFILE;
901 ret = uprobe_buffer_enable();
905 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
910 tu->consumer.filter = filter;
911 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
914 list_del(&link->list);
916 tu->tp.flags &= ~TP_FLAG_TRACE;
918 tu->tp.flags &= ~TP_FLAG_PROFILE;
925 probe_event_disable(struct trace_uprobe *tu, struct ftrace_event_file *file)
927 if (!trace_probe_is_enabled(&tu->tp))
931 struct event_file_link *link;
933 link = find_event_file_link(&tu->tp, file);
937 list_del_rcu(&link->list);
938 /* synchronize with u{,ret}probe_trace_func */
942 if (!list_empty(&tu->tp.files))
946 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
948 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
949 tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
951 uprobe_buffer_disable();
954 static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
957 struct uprobe_trace_entry_head field;
958 struct trace_uprobe *tu = event_call->data;
960 if (is_ret_probe(tu)) {
961 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
962 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
963 size = SIZEOF_TRACE_ENTRY(true);
965 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
966 size = SIZEOF_TRACE_ENTRY(false);
968 /* Set argument names as fields */
969 for (i = 0; i < tu->tp.nr_args; i++) {
970 struct probe_arg *parg = &tu->tp.args[i];
972 ret = trace_define_field(event_call, parg->type->fmttype,
973 parg->name, size + parg->offset,
974 parg->type->size, parg->type->is_signed,
983 #ifdef CONFIG_PERF_EVENTS
985 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
987 struct perf_event *event;
989 if (filter->nr_systemwide)
992 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
993 if (event->hw.tp_target->mm == mm)
1001 uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1003 return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm);
1006 static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1010 write_lock(&tu->filter.rwlock);
1011 if (event->hw.tp_target) {
1013 * event->parent != NULL means copy_process(), we can avoid
1014 * uprobe_apply(). current->mm must be probed and we can rely
1015 * on dup_mmap() which preserves the already installed bp's.
1017 * attr.enable_on_exec means that exec/mmap will install the
1018 * breakpoints we need.
1020 done = tu->filter.nr_systemwide ||
1021 event->parent || event->attr.enable_on_exec ||
1022 uprobe_filter_event(tu, event);
1023 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1025 done = tu->filter.nr_systemwide;
1026 tu->filter.nr_systemwide++;
1028 write_unlock(&tu->filter.rwlock);
1031 uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1036 static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1040 write_lock(&tu->filter.rwlock);
1041 if (event->hw.tp_target) {
1042 list_del(&event->hw.tp_list);
1043 done = tu->filter.nr_systemwide ||
1044 (event->hw.tp_target->flags & PF_EXITING) ||
1045 uprobe_filter_event(tu, event);
1047 tu->filter.nr_systemwide--;
1048 done = tu->filter.nr_systemwide;
1050 write_unlock(&tu->filter.rwlock);
1053 uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1058 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1059 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1061 struct trace_uprobe *tu;
1064 tu = container_of(uc, struct trace_uprobe, consumer);
1065 read_lock(&tu->filter.rwlock);
1066 ret = __uprobe_perf_filter(&tu->filter, mm);
1067 read_unlock(&tu->filter.rwlock);
1072 static void __uprobe_perf_func(struct trace_uprobe *tu,
1073 unsigned long func, struct pt_regs *regs,
1074 struct uprobe_cpu_buffer *ucb, int dsize)
1076 struct ftrace_event_call *call = &tu->tp.call;
1077 struct uprobe_trace_entry_head *entry;
1078 struct hlist_head *head;
1083 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1085 size = esize + tu->tp.size + dsize;
1086 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1087 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1091 head = this_cpu_ptr(call->perf_events);
1092 if (hlist_empty(head))
1095 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1099 if (is_ret_probe(tu)) {
1100 entry->vaddr[0] = func;
1101 entry->vaddr[1] = instruction_pointer(regs);
1102 data = DATAOF_TRACE_ENTRY(entry, true);
1104 entry->vaddr[0] = instruction_pointer(regs);
1105 data = DATAOF_TRACE_ENTRY(entry, false);
1108 memcpy(data, ucb->buf, tu->tp.size + dsize);
1110 if (size - esize > tu->tp.size + dsize) {
1111 int len = tu->tp.size + dsize;
1113 memset(data + len, 0, size - esize - len);
1116 perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
1121 /* uprobe profile handler */
1122 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1123 struct uprobe_cpu_buffer *ucb, int dsize)
1125 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1126 return UPROBE_HANDLER_REMOVE;
1128 if (!is_ret_probe(tu))
1129 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1133 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1134 struct pt_regs *regs,
1135 struct uprobe_cpu_buffer *ucb, int dsize)
1137 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1139 #endif /* CONFIG_PERF_EVENTS */
1142 trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
1145 struct trace_uprobe *tu = event->data;
1146 struct ftrace_event_file *file = data;
1149 case TRACE_REG_REGISTER:
1150 return probe_event_enable(tu, file, NULL);
1152 case TRACE_REG_UNREGISTER:
1153 probe_event_disable(tu, file);
1156 #ifdef CONFIG_PERF_EVENTS
1157 case TRACE_REG_PERF_REGISTER:
1158 return probe_event_enable(tu, NULL, uprobe_perf_filter);
1160 case TRACE_REG_PERF_UNREGISTER:
1161 probe_event_disable(tu, NULL);
1164 case TRACE_REG_PERF_OPEN:
1165 return uprobe_perf_open(tu, data);
1167 case TRACE_REG_PERF_CLOSE:
1168 return uprobe_perf_close(tu, data);
1177 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1179 struct trace_uprobe *tu;
1180 struct uprobe_dispatch_data udd;
1181 struct uprobe_cpu_buffer *ucb;
1186 tu = container_of(con, struct trace_uprobe, consumer);
1190 udd.bp_addr = instruction_pointer(regs);
1192 current->utask->vaddr = (unsigned long) &udd;
1194 #ifdef CONFIG_PERF_EVENTS
1195 if ((tu->tp.flags & TP_FLAG_TRACE) == 0 &&
1196 !uprobe_perf_filter(&tu->consumer, 0, current->mm))
1197 return UPROBE_HANDLER_REMOVE;
1200 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1203 dsize = __get_data_size(&tu->tp, regs);
1204 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1206 ucb = uprobe_buffer_get();
1207 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1209 if (tu->tp.flags & TP_FLAG_TRACE)
1210 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1212 #ifdef CONFIG_PERF_EVENTS
1213 if (tu->tp.flags & TP_FLAG_PROFILE)
1214 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1216 uprobe_buffer_put(ucb);
1220 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1221 unsigned long func, struct pt_regs *regs)
1223 struct trace_uprobe *tu;
1224 struct uprobe_dispatch_data udd;
1225 struct uprobe_cpu_buffer *ucb;
1228 tu = container_of(con, struct trace_uprobe, consumer);
1233 current->utask->vaddr = (unsigned long) &udd;
1235 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1238 dsize = __get_data_size(&tu->tp, regs);
1239 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1241 ucb = uprobe_buffer_get();
1242 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1244 if (tu->tp.flags & TP_FLAG_TRACE)
1245 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1247 #ifdef CONFIG_PERF_EVENTS
1248 if (tu->tp.flags & TP_FLAG_PROFILE)
1249 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1251 uprobe_buffer_put(ucb);
1255 static struct trace_event_functions uprobe_funcs = {
1256 .trace = print_uprobe_event
1259 static int register_uprobe_event(struct trace_uprobe *tu)
1261 struct ftrace_event_call *call = &tu->tp.call;
1264 /* Initialize ftrace_event_call */
1265 INIT_LIST_HEAD(&call->class->fields);
1266 call->event.funcs = &uprobe_funcs;
1267 call->class->define_fields = uprobe_event_define_fields;
1269 if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
1272 ret = register_ftrace_event(&call->event);
1274 kfree(call->print_fmt);
1278 call->class->reg = trace_uprobe_register;
1280 ret = trace_add_event_call(call);
1283 pr_info("Failed to register uprobe event: %s\n",
1284 ftrace_event_name(call));
1285 kfree(call->print_fmt);
1286 unregister_ftrace_event(&call->event);
1292 static int unregister_uprobe_event(struct trace_uprobe *tu)
1296 /* tu->event is unregistered in trace_remove_event_call() */
1297 ret = trace_remove_event_call(&tu->tp.call);
1300 kfree(tu->tp.call.print_fmt);
1301 tu->tp.call.print_fmt = NULL;
1305 /* Make a trace interface for controling probe points */
1306 static __init int init_uprobe_trace(void)
1308 struct dentry *d_tracer;
1310 d_tracer = tracing_init_dentry();
1314 trace_create_file("uprobe_events", 0644, d_tracer,
1315 NULL, &uprobe_events_ops);
1316 /* Profile interface */
1317 trace_create_file("uprobe_profile", 0444, d_tracer,
1318 NULL, &uprobe_profile_ops);
1322 fs_initcall(init_uprobe_trace);