1 #include <trace/syscall.h>
2 #include <trace/events/syscalls.h>
3 #include <linux/kernel.h>
4 #include <linux/ftrace.h>
5 #include <linux/perf_event.h>
6 #include <asm/syscall.h>
8 #include "trace_output.h"
11 static DEFINE_MUTEX(syscall_trace_lock);
12 static int sys_refcount_enter;
13 static int sys_refcount_exit;
14 static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
15 static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
18 print_syscall_enter(struct trace_iterator *iter, int flags)
20 struct trace_seq *s = &iter->seq;
21 struct trace_entry *ent = iter->ent;
22 struct syscall_trace_enter *trace;
23 struct syscall_metadata *entry;
26 trace = (typeof(trace))ent;
28 entry = syscall_nr_to_meta(syscall);
33 if (entry->enter_id != ent->type) {
38 ret = trace_seq_printf(s, "%s(", entry->name);
40 return TRACE_TYPE_PARTIAL_LINE;
42 for (i = 0; i < entry->nb_args; i++) {
44 if (trace_flags & TRACE_ITER_VERBOSE) {
45 ret = trace_seq_printf(s, "%s ", entry->types[i]);
47 return TRACE_TYPE_PARTIAL_LINE;
49 /* parameter values */
50 ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
52 i == entry->nb_args - 1 ? "" : ", ");
54 return TRACE_TYPE_PARTIAL_LINE;
57 ret = trace_seq_putc(s, ')');
59 return TRACE_TYPE_PARTIAL_LINE;
62 ret = trace_seq_putc(s, '\n');
64 return TRACE_TYPE_PARTIAL_LINE;
66 return TRACE_TYPE_HANDLED;
70 print_syscall_exit(struct trace_iterator *iter, int flags)
72 struct trace_seq *s = &iter->seq;
73 struct trace_entry *ent = iter->ent;
74 struct syscall_trace_exit *trace;
76 struct syscall_metadata *entry;
79 trace = (typeof(trace))ent;
81 entry = syscall_nr_to_meta(syscall);
84 trace_seq_printf(s, "\n");
85 return TRACE_TYPE_HANDLED;
88 if (entry->exit_id != ent->type) {
90 return TRACE_TYPE_UNHANDLED;
93 ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
96 return TRACE_TYPE_PARTIAL_LINE;
98 return TRACE_TYPE_HANDLED;
101 extern char *__bad_type_size(void);
103 #define SYSCALL_FIELD(type, name) \
104 sizeof(type) != sizeof(trace.name) ? \
105 __bad_type_size() : \
106 #type, #name, offsetof(typeof(trace), name), \
107 sizeof(trace.name), is_signed_type(type)
109 int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s)
114 struct syscall_metadata *entry;
115 struct syscall_trace_enter trace;
116 int offset = offsetof(struct syscall_trace_enter, args);
118 nr = syscall_name_to_nr(call->data);
119 entry = syscall_nr_to_meta(nr);
124 ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
126 SYSCALL_FIELD(int, nr));
130 for (i = 0; i < entry->nb_args; i++) {
131 ret = trace_seq_printf(s, "\tfield:%s %s;", entry->types[i],
135 ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;"
136 "\tsigned:%u;\n", offset,
137 sizeof(unsigned long),
138 is_signed_type(unsigned long));
141 offset += sizeof(unsigned long);
144 trace_seq_puts(s, "\nprint fmt: \"");
145 for (i = 0; i < entry->nb_args; i++) {
146 ret = trace_seq_printf(s, "%s: 0x%%0%zulx%s", entry->args[i],
147 sizeof(unsigned long),
148 i == entry->nb_args - 1 ? "" : ", ");
152 trace_seq_putc(s, '"');
154 for (i = 0; i < entry->nb_args; i++) {
155 ret = trace_seq_printf(s, ", ((unsigned long)(REC->%s))",
161 return trace_seq_putc(s, '\n');
164 int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
167 struct syscall_trace_exit trace;
169 ret = trace_seq_printf(s,
170 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
172 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
174 SYSCALL_FIELD(int, nr),
175 SYSCALL_FIELD(long, ret));
179 return trace_seq_printf(s, "\nprint fmt: \"0x%%lx\", REC->ret\n");
182 int syscall_enter_define_fields(struct ftrace_event_call *call)
184 struct syscall_trace_enter trace;
185 struct syscall_metadata *meta;
189 int offset = offsetof(typeof(trace), args);
191 nr = syscall_name_to_nr(call->data);
192 meta = syscall_nr_to_meta(nr);
197 ret = trace_define_common_fields(call);
201 for (i = 0; i < meta->nb_args; i++) {
202 ret = trace_define_field(call, meta->types[i],
203 meta->args[i], offset,
204 sizeof(unsigned long), 0,
206 offset += sizeof(unsigned long);
212 int syscall_exit_define_fields(struct ftrace_event_call *call)
214 struct syscall_trace_exit trace;
217 ret = trace_define_common_fields(call);
221 ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
227 void ftrace_syscall_enter(struct pt_regs *regs, long id)
229 struct syscall_trace_enter *entry;
230 struct syscall_metadata *sys_data;
231 struct ring_buffer_event *event;
232 struct ring_buffer *buffer;
236 syscall_nr = syscall_get_nr(current, regs);
239 if (!test_bit(syscall_nr, enabled_enter_syscalls))
242 sys_data = syscall_nr_to_meta(syscall_nr);
246 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
248 event = trace_current_buffer_lock_reserve(&buffer, sys_data->enter_id,
253 entry = ring_buffer_event_data(event);
254 entry->nr = syscall_nr;
255 syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
257 if (!filter_current_check_discard(buffer, sys_data->enter_event,
259 trace_current_buffer_unlock_commit(buffer, event, 0, 0);
262 void ftrace_syscall_exit(struct pt_regs *regs, long ret)
264 struct syscall_trace_exit *entry;
265 struct syscall_metadata *sys_data;
266 struct ring_buffer_event *event;
267 struct ring_buffer *buffer;
270 syscall_nr = syscall_get_nr(current, regs);
273 if (!test_bit(syscall_nr, enabled_exit_syscalls))
276 sys_data = syscall_nr_to_meta(syscall_nr);
280 event = trace_current_buffer_lock_reserve(&buffer, sys_data->exit_id,
281 sizeof(*entry), 0, 0);
285 entry = ring_buffer_event_data(event);
286 entry->nr = syscall_nr;
287 entry->ret = syscall_get_return_value(current, regs);
289 if (!filter_current_check_discard(buffer, sys_data->exit_event,
291 trace_current_buffer_unlock_commit(buffer, event, 0, 0);
294 int reg_event_syscall_enter(void *ptr)
301 num = syscall_name_to_nr(name);
302 if (num < 0 || num >= NR_syscalls)
304 mutex_lock(&syscall_trace_lock);
305 if (!sys_refcount_enter)
306 ret = register_trace_sys_enter(ftrace_syscall_enter);
308 pr_info("event trace: Could not activate"
309 "syscall entry trace point");
311 set_bit(num, enabled_enter_syscalls);
312 sys_refcount_enter++;
314 mutex_unlock(&syscall_trace_lock);
318 void unreg_event_syscall_enter(void *ptr)
324 num = syscall_name_to_nr(name);
325 if (num < 0 || num >= NR_syscalls)
327 mutex_lock(&syscall_trace_lock);
328 sys_refcount_enter--;
329 clear_bit(num, enabled_enter_syscalls);
330 if (!sys_refcount_enter)
331 unregister_trace_sys_enter(ftrace_syscall_enter);
332 mutex_unlock(&syscall_trace_lock);
335 int reg_event_syscall_exit(void *ptr)
342 num = syscall_name_to_nr(name);
343 if (num < 0 || num >= NR_syscalls)
345 mutex_lock(&syscall_trace_lock);
346 if (!sys_refcount_exit)
347 ret = register_trace_sys_exit(ftrace_syscall_exit);
349 pr_info("event trace: Could not activate"
350 "syscall exit trace point");
352 set_bit(num, enabled_exit_syscalls);
355 mutex_unlock(&syscall_trace_lock);
359 void unreg_event_syscall_exit(void *ptr)
365 num = syscall_name_to_nr(name);
366 if (num < 0 || num >= NR_syscalls)
368 mutex_lock(&syscall_trace_lock);
370 clear_bit(num, enabled_exit_syscalls);
371 if (!sys_refcount_exit)
372 unregister_trace_sys_exit(ftrace_syscall_exit);
373 mutex_unlock(&syscall_trace_lock);
376 struct trace_event event_syscall_enter = {
377 .trace = print_syscall_enter,
380 struct trace_event event_syscall_exit = {
381 .trace = print_syscall_exit,
384 #ifdef CONFIG_EVENT_PROFILE
386 static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls);
387 static DECLARE_BITMAP(enabled_prof_exit_syscalls, NR_syscalls);
388 static int sys_prof_refcount_enter;
389 static int sys_prof_refcount_exit;
391 static void prof_syscall_enter(struct pt_regs *regs, long id)
393 struct syscall_metadata *sys_data;
394 struct syscall_trace_enter *rec;
401 syscall_nr = syscall_get_nr(current, regs);
402 if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
405 sys_data = syscall_nr_to_meta(syscall_nr);
409 /* get the size after alignment with the u32 buffer size field */
410 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
411 size = ALIGN(size + sizeof(u32), sizeof(u64));
414 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
415 "profile buffer not large enough"))
418 /* Protect the per cpu buffer, begin the rcu read side */
419 local_irq_save(flags);
421 cpu = smp_processor_id();
424 raw_data = rcu_dereference(trace_profile_buf_nmi);
426 raw_data = rcu_dereference(trace_profile_buf);
431 raw_data = per_cpu_ptr(raw_data, cpu);
433 /* zero the dead bytes from align to not leak stack to user */
434 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
436 rec = (struct syscall_trace_enter *) raw_data;
437 tracing_generic_entry_update(&rec->ent, 0, 0);
438 rec->ent.type = sys_data->enter_id;
439 rec->nr = syscall_nr;
440 syscall_get_arguments(current, regs, 0, sys_data->nb_args,
441 (unsigned long *)&rec->args);
442 perf_tp_event(sys_data->enter_id, 0, 1, rec, size);
445 local_irq_restore(flags);
448 int reg_prof_syscall_enter(char *name)
453 num = syscall_name_to_nr(name);
454 if (num < 0 || num >= NR_syscalls)
457 mutex_lock(&syscall_trace_lock);
458 if (!sys_prof_refcount_enter)
459 ret = register_trace_sys_enter(prof_syscall_enter);
461 pr_info("event trace: Could not activate"
462 "syscall entry trace point");
464 set_bit(num, enabled_prof_enter_syscalls);
465 sys_prof_refcount_enter++;
467 mutex_unlock(&syscall_trace_lock);
471 void unreg_prof_syscall_enter(char *name)
475 num = syscall_name_to_nr(name);
476 if (num < 0 || num >= NR_syscalls)
479 mutex_lock(&syscall_trace_lock);
480 sys_prof_refcount_enter--;
481 clear_bit(num, enabled_prof_enter_syscalls);
482 if (!sys_prof_refcount_enter)
483 unregister_trace_sys_enter(prof_syscall_enter);
484 mutex_unlock(&syscall_trace_lock);
487 static void prof_syscall_exit(struct pt_regs *regs, long ret)
489 struct syscall_metadata *sys_data;
490 struct syscall_trace_exit *rec;
497 syscall_nr = syscall_get_nr(current, regs);
498 if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
501 sys_data = syscall_nr_to_meta(syscall_nr);
505 /* We can probably do that at build time */
506 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
510 * Impossible, but be paranoid with the future
511 * How to put this check outside runtime?
513 if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
514 "exit event has grown above profile buffer size"))
517 /* Protect the per cpu buffer, begin the rcu read side */
518 local_irq_save(flags);
519 cpu = smp_processor_id();
522 raw_data = rcu_dereference(trace_profile_buf_nmi);
524 raw_data = rcu_dereference(trace_profile_buf);
529 raw_data = per_cpu_ptr(raw_data, cpu);
531 /* zero the dead bytes from align to not leak stack to user */
532 *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
534 rec = (struct syscall_trace_exit *)raw_data;
536 tracing_generic_entry_update(&rec->ent, 0, 0);
537 rec->ent.type = sys_data->exit_id;
538 rec->nr = syscall_nr;
539 rec->ret = syscall_get_return_value(current, regs);
541 perf_tp_event(sys_data->exit_id, 0, 1, rec, size);
544 local_irq_restore(flags);
547 int reg_prof_syscall_exit(char *name)
552 num = syscall_name_to_nr(name);
553 if (num < 0 || num >= NR_syscalls)
556 mutex_lock(&syscall_trace_lock);
557 if (!sys_prof_refcount_exit)
558 ret = register_trace_sys_exit(prof_syscall_exit);
560 pr_info("event trace: Could not activate"
561 "syscall entry trace point");
563 set_bit(num, enabled_prof_exit_syscalls);
564 sys_prof_refcount_exit++;
566 mutex_unlock(&syscall_trace_lock);
570 void unreg_prof_syscall_exit(char *name)
574 num = syscall_name_to_nr(name);
575 if (num < 0 || num >= NR_syscalls)
578 mutex_lock(&syscall_trace_lock);
579 sys_prof_refcount_exit--;
580 clear_bit(num, enabled_prof_exit_syscalls);
581 if (!sys_prof_refcount_exit)
582 unregister_trace_sys_exit(prof_syscall_exit);
583 mutex_unlock(&syscall_trace_lock);