1 #include <trace/syscall.h>
2 #include <linux/kernel.h>
3 #include <linux/ftrace.h>
4 #include <asm/syscall.h>
6 #include "trace_output.h"
9 static DEFINE_MUTEX(syscall_trace_lock
);
10 static int sys_refcount_enter
;
11 static int sys_refcount_exit
;
12 static DECLARE_BITMAP(enabled_enter_syscalls
, FTRACE_SYSCALL_MAX
);
13 static DECLARE_BITMAP(enabled_exit_syscalls
, FTRACE_SYSCALL_MAX
);
15 /* Option to display the parameters types */
17 TRACE_SYSCALLS_OPT_TYPES
= 0x1,
20 static struct tracer_opt syscalls_opts
[] = {
21 { TRACER_OPT(syscall_arg_type
, TRACE_SYSCALLS_OPT_TYPES
) },
25 static struct tracer_flags syscalls_flags
= {
26 .val
= 0, /* By default: no parameters types */
31 print_syscall_enter(struct trace_iterator
*iter
, int flags
)
33 struct trace_seq
*s
= &iter
->seq
;
34 struct trace_entry
*ent
= iter
->ent
;
35 struct syscall_trace_enter
*trace
;
36 struct syscall_metadata
*entry
;
39 trace_assign_type(trace
, ent
);
43 entry
= syscall_nr_to_meta(syscall
);
47 ret
= trace_seq_printf(s
, "%s(", entry
->name
);
49 return TRACE_TYPE_PARTIAL_LINE
;
51 for (i
= 0; i
< entry
->nb_args
; i
++) {
53 if (syscalls_flags
.val
& TRACE_SYSCALLS_OPT_TYPES
) {
54 ret
= trace_seq_printf(s
, "%s ", entry
->types
[i
]);
56 return TRACE_TYPE_PARTIAL_LINE
;
58 /* parameter values */
59 ret
= trace_seq_printf(s
, "%s: %lx%s ", entry
->args
[i
],
61 i
== entry
->nb_args
- 1 ? ")" : ",");
63 return TRACE_TYPE_PARTIAL_LINE
;
67 trace_seq_printf(s
, "\n");
68 return TRACE_TYPE_HANDLED
;
72 print_syscall_exit(struct trace_iterator
*iter
, int flags
)
74 struct trace_seq
*s
= &iter
->seq
;
75 struct trace_entry
*ent
= iter
->ent
;
76 struct syscall_trace_exit
*trace
;
78 struct syscall_metadata
*entry
;
81 trace_assign_type(trace
, ent
);
85 entry
= syscall_nr_to_meta(syscall
);
87 trace_seq_printf(s
, "\n");
88 return TRACE_TYPE_HANDLED
;
91 ret
= trace_seq_printf(s
, "%s -> 0x%lx\n", entry
->name
,
94 return TRACE_TYPE_PARTIAL_LINE
;
96 return TRACE_TYPE_HANDLED
;
99 void ftrace_syscall_enter(struct pt_regs
*regs
, long id
)
101 struct syscall_trace_enter
*entry
;
102 struct syscall_metadata
*sys_data
;
103 struct ring_buffer_event
*event
;
107 syscall_nr
= syscall_get_nr(current
, regs
);
108 if (!test_bit(syscall_nr
, enabled_enter_syscalls
))
111 sys_data
= syscall_nr_to_meta(syscall_nr
);
115 size
= sizeof(*entry
) + sizeof(unsigned long) * sys_data
->nb_args
;
117 event
= trace_current_buffer_lock_reserve(TRACE_SYSCALL_ENTER
, size
,
122 entry
= ring_buffer_event_data(event
);
123 entry
->nr
= syscall_nr
;
124 syscall_get_arguments(current
, regs
, 0, sys_data
->nb_args
, entry
->args
);
126 trace_current_buffer_unlock_commit(event
, 0, 0);
130 void ftrace_syscall_exit(struct pt_regs
*regs
, long ret
)
132 struct syscall_trace_exit
*entry
;
133 struct syscall_metadata
*sys_data
;
134 struct ring_buffer_event
*event
;
137 syscall_nr
= syscall_get_nr(current
, regs
);
138 if (!test_bit(syscall_nr
, enabled_exit_syscalls
))
141 sys_data
= syscall_nr_to_meta(syscall_nr
);
145 event
= trace_current_buffer_lock_reserve(TRACE_SYSCALL_EXIT
,
146 sizeof(*entry
), 0, 0);
150 entry
= ring_buffer_event_data(event
);
151 entry
->nr
= syscall_nr
;
152 entry
->ret
= syscall_get_return_value(current
, regs
);
154 trace_current_buffer_unlock_commit(event
, 0, 0);
158 int reg_event_syscall_enter(void *ptr
)
165 num
= syscall_name_to_nr(name
);
166 if (num
< 0 || num
>= FTRACE_SYSCALL_MAX
)
168 mutex_lock(&syscall_trace_lock
);
169 if (!sys_refcount_enter
)
170 ret
= register_trace_syscall_enter(ftrace_syscall_enter
);
172 pr_info("event trace: Could not activate"
173 "syscall entry trace point");
175 set_bit(num
, enabled_enter_syscalls
);
176 sys_refcount_enter
++;
178 mutex_unlock(&syscall_trace_lock
);
182 void unreg_event_syscall_enter(void *ptr
)
188 num
= syscall_name_to_nr(name
);
189 if (num
< 0 || num
>= FTRACE_SYSCALL_MAX
)
191 mutex_lock(&syscall_trace_lock
);
192 sys_refcount_enter
--;
193 clear_bit(num
, enabled_enter_syscalls
);
194 if (!sys_refcount_enter
)
195 unregister_trace_syscall_enter(ftrace_syscall_enter
);
196 mutex_unlock(&syscall_trace_lock
);
199 int reg_event_syscall_exit(void *ptr
)
206 num
= syscall_name_to_nr(name
);
207 if (num
< 0 || num
>= FTRACE_SYSCALL_MAX
)
209 mutex_lock(&syscall_trace_lock
);
210 if (!sys_refcount_exit
)
211 ret
= register_trace_syscall_exit(ftrace_syscall_exit
);
213 pr_info("event trace: Could not activate"
214 "syscall exit trace point");
216 set_bit(num
, enabled_exit_syscalls
);
219 mutex_unlock(&syscall_trace_lock
);
223 void unreg_event_syscall_exit(void *ptr
)
229 num
= syscall_name_to_nr(name
);
230 if (num
< 0 || num
>= FTRACE_SYSCALL_MAX
)
232 mutex_lock(&syscall_trace_lock
);
234 clear_bit(num
, enabled_exit_syscalls
);
235 if (!sys_refcount_exit
)
236 unregister_trace_syscall_exit(ftrace_syscall_exit
);
237 mutex_unlock(&syscall_trace_lock
);
240 struct trace_event event_syscall_enter
= {
241 .trace
= print_syscall_enter
,
242 .type
= TRACE_SYSCALL_ENTER
245 struct trace_event event_syscall_exit
= {
246 .trace
= print_syscall_exit
,
247 .type
= TRACE_SYSCALL_EXIT