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
);
17 extern unsigned long __start_syscalls_metadata
[];
18 extern unsigned long __stop_syscalls_metadata
[];
20 static struct syscall_metadata
**syscalls_metadata
;
22 static struct syscall_metadata
*find_syscall_meta(unsigned long syscall
)
24 struct syscall_metadata
*start
;
25 struct syscall_metadata
*stop
;
26 char str
[KSYM_SYMBOL_LEN
];
29 start
= (struct syscall_metadata
*)__start_syscalls_metadata
;
30 stop
= (struct syscall_metadata
*)__stop_syscalls_metadata
;
31 kallsyms_lookup(syscall
, NULL
, NULL
, NULL
, str
);
33 for ( ; start
< stop
; start
++) {
35 * Only compare after the "sys" prefix. Archs that use
36 * syscall wrappers may have syscalls symbols aliases prefixed
37 * with "SyS" instead of "sys", leading to an unwanted
40 if (start
->name
&& !strcmp(start
->name
+ 3, str
+ 3))
46 static struct syscall_metadata
*syscall_nr_to_meta(int nr
)
48 if (!syscalls_metadata
|| nr
>= NR_syscalls
|| nr
< 0)
51 return syscalls_metadata
[nr
];
55 print_syscall_enter(struct trace_iterator
*iter
, int flags
)
57 struct trace_seq
*s
= &iter
->seq
;
58 struct trace_entry
*ent
= iter
->ent
;
59 struct syscall_trace_enter
*trace
;
60 struct syscall_metadata
*entry
;
63 trace
= (typeof(trace
))ent
;
65 entry
= syscall_nr_to_meta(syscall
);
70 if (entry
->enter_event
->id
!= ent
->type
) {
75 ret
= trace_seq_printf(s
, "%s(", entry
->name
);
77 return TRACE_TYPE_PARTIAL_LINE
;
79 for (i
= 0; i
< entry
->nb_args
; i
++) {
81 if (trace_flags
& TRACE_ITER_VERBOSE
) {
82 ret
= trace_seq_printf(s
, "%s ", entry
->types
[i
]);
84 return TRACE_TYPE_PARTIAL_LINE
;
86 /* parameter values */
87 ret
= trace_seq_printf(s
, "%s: %lx%s", entry
->args
[i
],
89 i
== entry
->nb_args
- 1 ? "" : ", ");
91 return TRACE_TYPE_PARTIAL_LINE
;
94 ret
= trace_seq_putc(s
, ')');
96 return TRACE_TYPE_PARTIAL_LINE
;
99 ret
= trace_seq_putc(s
, '\n');
101 return TRACE_TYPE_PARTIAL_LINE
;
103 return TRACE_TYPE_HANDLED
;
107 print_syscall_exit(struct trace_iterator
*iter
, int flags
)
109 struct trace_seq
*s
= &iter
->seq
;
110 struct trace_entry
*ent
= iter
->ent
;
111 struct syscall_trace_exit
*trace
;
113 struct syscall_metadata
*entry
;
116 trace
= (typeof(trace
))ent
;
118 entry
= syscall_nr_to_meta(syscall
);
121 trace_seq_printf(s
, "\n");
122 return TRACE_TYPE_HANDLED
;
125 if (entry
->exit_event
->id
!= ent
->type
) {
127 return TRACE_TYPE_UNHANDLED
;
130 ret
= trace_seq_printf(s
, "%s -> 0x%lx\n", entry
->name
,
133 return TRACE_TYPE_PARTIAL_LINE
;
135 return TRACE_TYPE_HANDLED
;
138 extern char *__bad_type_size(void);
140 #define SYSCALL_FIELD(type, name) \
141 sizeof(type) != sizeof(trace.name) ? \
142 __bad_type_size() : \
143 #type, #name, offsetof(typeof(trace), name), \
144 sizeof(trace.name), is_signed_type(type)
146 int syscall_enter_format(struct ftrace_event_call
*call
, struct trace_seq
*s
)
150 struct syscall_metadata
*entry
= call
->data
;
151 struct syscall_trace_enter trace
;
152 int offset
= offsetof(struct syscall_trace_enter
, args
);
154 ret
= trace_seq_printf(s
, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
156 SYSCALL_FIELD(int, nr
));
160 for (i
= 0; i
< entry
->nb_args
; i
++) {
161 ret
= trace_seq_printf(s
, "\tfield:%s %s;", entry
->types
[i
],
165 ret
= trace_seq_printf(s
, "\toffset:%d;\tsize:%zu;"
166 "\tsigned:%u;\n", offset
,
167 sizeof(unsigned long),
168 is_signed_type(unsigned long));
171 offset
+= sizeof(unsigned long);
174 trace_seq_puts(s
, "\nprint fmt: \"");
175 for (i
= 0; i
< entry
->nb_args
; i
++) {
176 ret
= trace_seq_printf(s
, "%s: 0x%%0%zulx%s", entry
->args
[i
],
177 sizeof(unsigned long),
178 i
== entry
->nb_args
- 1 ? "" : ", ");
182 trace_seq_putc(s
, '"');
184 for (i
= 0; i
< entry
->nb_args
; i
++) {
185 ret
= trace_seq_printf(s
, ", ((unsigned long)(REC->%s))",
191 return trace_seq_putc(s
, '\n');
194 int syscall_exit_format(struct ftrace_event_call
*call
, struct trace_seq
*s
)
197 struct syscall_trace_exit trace
;
199 ret
= trace_seq_printf(s
,
200 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
202 "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
204 SYSCALL_FIELD(int, nr
),
205 SYSCALL_FIELD(long, ret
));
209 return trace_seq_printf(s
, "\nprint fmt: \"0x%%lx\", REC->ret\n");
212 int syscall_enter_define_fields(struct ftrace_event_call
*call
)
214 struct syscall_trace_enter trace
;
215 struct syscall_metadata
*meta
= call
->data
;
218 int offset
= offsetof(typeof(trace
), args
);
220 ret
= trace_define_common_fields(call
);
224 ret
= trace_define_field(call
, SYSCALL_FIELD(int, nr
), FILTER_OTHER
);
228 for (i
= 0; i
< meta
->nb_args
; i
++) {
229 ret
= trace_define_field(call
, meta
->types
[i
],
230 meta
->args
[i
], offset
,
231 sizeof(unsigned long), 0,
233 offset
+= sizeof(unsigned long);
239 int syscall_exit_define_fields(struct ftrace_event_call
*call
)
241 struct syscall_trace_exit trace
;
244 ret
= trace_define_common_fields(call
);
248 ret
= trace_define_field(call
, SYSCALL_FIELD(int, nr
), FILTER_OTHER
);
252 ret
= trace_define_field(call
, SYSCALL_FIELD(long, ret
),
258 void ftrace_syscall_enter(struct pt_regs
*regs
, long id
)
260 struct syscall_trace_enter
*entry
;
261 struct syscall_metadata
*sys_data
;
262 struct ring_buffer_event
*event
;
263 struct ring_buffer
*buffer
;
267 syscall_nr
= syscall_get_nr(current
, regs
);
270 if (!test_bit(syscall_nr
, enabled_enter_syscalls
))
273 sys_data
= syscall_nr_to_meta(syscall_nr
);
277 size
= sizeof(*entry
) + sizeof(unsigned long) * sys_data
->nb_args
;
279 event
= trace_current_buffer_lock_reserve(&buffer
,
280 sys_data
->enter_event
->id
, size
, 0, 0);
284 entry
= ring_buffer_event_data(event
);
285 entry
->nr
= syscall_nr
;
286 syscall_get_arguments(current
, regs
, 0, sys_data
->nb_args
, entry
->args
);
288 if (!filter_current_check_discard(buffer
, sys_data
->enter_event
,
290 trace_current_buffer_unlock_commit(buffer
, event
, 0, 0);
293 void ftrace_syscall_exit(struct pt_regs
*regs
, long ret
)
295 struct syscall_trace_exit
*entry
;
296 struct syscall_metadata
*sys_data
;
297 struct ring_buffer_event
*event
;
298 struct ring_buffer
*buffer
;
301 syscall_nr
= syscall_get_nr(current
, regs
);
304 if (!test_bit(syscall_nr
, enabled_exit_syscalls
))
307 sys_data
= syscall_nr_to_meta(syscall_nr
);
311 event
= trace_current_buffer_lock_reserve(&buffer
,
312 sys_data
->exit_event
->id
, sizeof(*entry
), 0, 0);
316 entry
= ring_buffer_event_data(event
);
317 entry
->nr
= syscall_nr
;
318 entry
->ret
= syscall_get_return_value(current
, regs
);
320 if (!filter_current_check_discard(buffer
, sys_data
->exit_event
,
322 trace_current_buffer_unlock_commit(buffer
, event
, 0, 0);
325 int reg_event_syscall_enter(struct ftrace_event_call
*call
)
330 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
331 if (num
< 0 || num
>= NR_syscalls
)
333 mutex_lock(&syscall_trace_lock
);
334 if (!sys_refcount_enter
)
335 ret
= register_trace_sys_enter(ftrace_syscall_enter
);
337 pr_info("event trace: Could not activate"
338 "syscall entry trace point");
340 set_bit(num
, enabled_enter_syscalls
);
341 sys_refcount_enter
++;
343 mutex_unlock(&syscall_trace_lock
);
347 void unreg_event_syscall_enter(struct ftrace_event_call
*call
)
351 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
352 if (num
< 0 || num
>= NR_syscalls
)
354 mutex_lock(&syscall_trace_lock
);
355 sys_refcount_enter
--;
356 clear_bit(num
, enabled_enter_syscalls
);
357 if (!sys_refcount_enter
)
358 unregister_trace_sys_enter(ftrace_syscall_enter
);
359 mutex_unlock(&syscall_trace_lock
);
362 int reg_event_syscall_exit(struct ftrace_event_call
*call
)
367 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
368 if (num
< 0 || num
>= NR_syscalls
)
370 mutex_lock(&syscall_trace_lock
);
371 if (!sys_refcount_exit
)
372 ret
= register_trace_sys_exit(ftrace_syscall_exit
);
374 pr_info("event trace: Could not activate"
375 "syscall exit trace point");
377 set_bit(num
, enabled_exit_syscalls
);
380 mutex_unlock(&syscall_trace_lock
);
384 void unreg_event_syscall_exit(struct ftrace_event_call
*call
)
388 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
389 if (num
< 0 || num
>= NR_syscalls
)
391 mutex_lock(&syscall_trace_lock
);
393 clear_bit(num
, enabled_exit_syscalls
);
394 if (!sys_refcount_exit
)
395 unregister_trace_sys_exit(ftrace_syscall_exit
);
396 mutex_unlock(&syscall_trace_lock
);
399 int init_syscall_trace(struct ftrace_event_call
*call
)
403 id
= register_ftrace_event(call
->event
);
407 INIT_LIST_HEAD(&call
->fields
);
411 int __init
init_ftrace_syscalls(void)
413 struct syscall_metadata
*meta
;
417 syscalls_metadata
= kzalloc(sizeof(*syscalls_metadata
) *
418 NR_syscalls
, GFP_KERNEL
);
419 if (!syscalls_metadata
) {
424 for (i
= 0; i
< NR_syscalls
; i
++) {
425 addr
= arch_syscall_addr(i
);
426 meta
= find_syscall_meta(addr
);
430 meta
->syscall_nr
= i
;
431 syscalls_metadata
[i
] = meta
;
436 core_initcall(init_ftrace_syscalls
);
438 #ifdef CONFIG_EVENT_PROFILE
440 static DECLARE_BITMAP(enabled_prof_enter_syscalls
, NR_syscalls
);
441 static DECLARE_BITMAP(enabled_prof_exit_syscalls
, NR_syscalls
);
442 static int sys_prof_refcount_enter
;
443 static int sys_prof_refcount_exit
;
445 static void prof_syscall_enter(struct pt_regs
*regs
, long id
)
447 struct syscall_metadata
*sys_data
;
448 struct syscall_trace_enter
*rec
;
457 syscall_nr
= syscall_get_nr(current
, regs
);
458 if (!test_bit(syscall_nr
, enabled_prof_enter_syscalls
))
461 sys_data
= syscall_nr_to_meta(syscall_nr
);
465 /* get the size after alignment with the u32 buffer size field */
466 size
= sizeof(unsigned long) * sys_data
->nb_args
+ sizeof(*rec
);
467 size
= ALIGN(size
+ sizeof(u32
), sizeof(u64
));
470 if (WARN_ONCE(size
> FTRACE_MAX_PROFILE_SIZE
,
471 "profile buffer not large enough"))
474 /* Protect the per cpu buffer, begin the rcu read side */
475 local_irq_save(flags
);
477 rctx
= perf_swevent_get_recursion_context();
481 cpu
= smp_processor_id();
483 trace_buf
= rcu_dereference(perf_trace_buf
);
488 raw_data
= per_cpu_ptr(trace_buf
, cpu
);
490 /* zero the dead bytes from align to not leak stack to user */
491 *(u64
*)(&raw_data
[size
- sizeof(u64
)]) = 0ULL;
493 rec
= (struct syscall_trace_enter
*) raw_data
;
494 tracing_generic_entry_update(&rec
->ent
, 0, 0);
495 rec
->ent
.type
= sys_data
->enter_event
->id
;
496 rec
->nr
= syscall_nr
;
497 syscall_get_arguments(current
, regs
, 0, sys_data
->nb_args
,
498 (unsigned long *)&rec
->args
);
499 perf_tp_event(sys_data
->enter_event
->id
, 0, 1, rec
, size
);
502 perf_swevent_put_recursion_context(rctx
);
504 local_irq_restore(flags
);
507 int prof_sysenter_enable(struct ftrace_event_call
*call
)
512 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
514 mutex_lock(&syscall_trace_lock
);
515 if (!sys_prof_refcount_enter
)
516 ret
= register_trace_sys_enter(prof_syscall_enter
);
518 pr_info("event trace: Could not activate"
519 "syscall entry trace point");
521 set_bit(num
, enabled_prof_enter_syscalls
);
522 sys_prof_refcount_enter
++;
524 mutex_unlock(&syscall_trace_lock
);
528 void prof_sysenter_disable(struct ftrace_event_call
*call
)
532 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
534 mutex_lock(&syscall_trace_lock
);
535 sys_prof_refcount_enter
--;
536 clear_bit(num
, enabled_prof_enter_syscalls
);
537 if (!sys_prof_refcount_enter
)
538 unregister_trace_sys_enter(prof_syscall_enter
);
539 mutex_unlock(&syscall_trace_lock
);
542 static void prof_syscall_exit(struct pt_regs
*regs
, long ret
)
544 struct syscall_metadata
*sys_data
;
545 struct syscall_trace_exit
*rec
;
554 syscall_nr
= syscall_get_nr(current
, regs
);
555 if (!test_bit(syscall_nr
, enabled_prof_exit_syscalls
))
558 sys_data
= syscall_nr_to_meta(syscall_nr
);
562 /* We can probably do that at build time */
563 size
= ALIGN(sizeof(*rec
) + sizeof(u32
), sizeof(u64
));
567 * Impossible, but be paranoid with the future
568 * How to put this check outside runtime?
570 if (WARN_ONCE(size
> FTRACE_MAX_PROFILE_SIZE
,
571 "exit event has grown above profile buffer size"))
574 /* Protect the per cpu buffer, begin the rcu read side */
575 local_irq_save(flags
);
577 rctx
= perf_swevent_get_recursion_context();
581 cpu
= smp_processor_id();
583 trace_buf
= rcu_dereference(perf_trace_buf
);
588 raw_data
= per_cpu_ptr(trace_buf
, cpu
);
590 /* zero the dead bytes from align to not leak stack to user */
591 *(u64
*)(&raw_data
[size
- sizeof(u64
)]) = 0ULL;
593 rec
= (struct syscall_trace_exit
*)raw_data
;
595 tracing_generic_entry_update(&rec
->ent
, 0, 0);
596 rec
->ent
.type
= sys_data
->exit_event
->id
;
597 rec
->nr
= syscall_nr
;
598 rec
->ret
= syscall_get_return_value(current
, regs
);
600 perf_tp_event(sys_data
->exit_event
->id
, 0, 1, rec
, size
);
603 perf_swevent_put_recursion_context(rctx
);
605 local_irq_restore(flags
);
608 int prof_sysexit_enable(struct ftrace_event_call
*call
)
613 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
615 mutex_lock(&syscall_trace_lock
);
616 if (!sys_prof_refcount_exit
)
617 ret
= register_trace_sys_exit(prof_syscall_exit
);
619 pr_info("event trace: Could not activate"
620 "syscall entry trace point");
622 set_bit(num
, enabled_prof_exit_syscalls
);
623 sys_prof_refcount_exit
++;
625 mutex_unlock(&syscall_trace_lock
);
629 void prof_sysexit_disable(struct ftrace_event_call
*call
)
633 num
= ((struct syscall_metadata
*)call
->data
)->syscall_nr
;
635 mutex_lock(&syscall_trace_lock
);
636 sys_prof_refcount_exit
--;
637 clear_bit(num
, enabled_prof_exit_syscalls
);
638 if (!sys_prof_refcount_exit
)
639 unregister_trace_sys_exit(prof_syscall_exit
);
640 mutex_unlock(&syscall_trace_lock
);