tracing: Fix null pointer deref with SEND_SIG_FORCED
[safe/jmp/linux-2.6] / include / trace / events / signal.h
1 #undef TRACE_SYSTEM
2 #define TRACE_SYSTEM signal
3
4 #if !defined(_TRACE_SIGNAL_H) || defined(TRACE_HEADER_MULTI_READ)
5 #define _TRACE_SIGNAL_H
6
7 #include <linux/signal.h>
8 #include <linux/sched.h>
9 #include <linux/tracepoint.h>
10
11 #define TP_STORE_SIGINFO(__entry, info)                         \
12         do {                                                    \
13                 if (info == SEND_SIG_NOINFO ||                  \
14                     info == SEND_SIG_FORCED) {                  \
15                         __entry->errno  = 0;                    \
16                         __entry->code   = SI_USER;              \
17                 } else if (info == SEND_SIG_PRIV) {             \
18                         __entry->errno  = 0;                    \
19                         __entry->code   = SI_KERNEL;            \
20                 } else {                                        \
21                         __entry->errno  = info->si_errno;       \
22                         __entry->code   = info->si_code;        \
23                 }                                               \
24         } while (0)
25
26 /**
27  * signal_generate - called when a signal is generated
28  * @sig: signal number
29  * @info: pointer to struct siginfo
30  * @task: pointer to struct task_struct
31  *
32  * Current process sends a 'sig' signal to 'task' process with
33  * 'info' siginfo. If 'info' is SEND_SIG_NOINFO or SEND_SIG_PRIV,
34  * 'info' is not a pointer and you can't access its field. Instead,
35  * SEND_SIG_NOINFO means that si_code is SI_USER, and SEND_SIG_PRIV
36  * means that si_code is SI_KERNEL.
37  */
38 TRACE_EVENT(signal_generate,
39
40         TP_PROTO(int sig, struct siginfo *info, struct task_struct *task),
41
42         TP_ARGS(sig, info, task),
43
44         TP_STRUCT__entry(
45                 __field(        int,    sig                     )
46                 __field(        int,    errno                   )
47                 __field(        int,    code                    )
48                 __array(        char,   comm,   TASK_COMM_LEN   )
49                 __field(        pid_t,  pid                     )
50         ),
51
52         TP_fast_assign(
53                 __entry->sig    = sig;
54                 TP_STORE_SIGINFO(__entry, info);
55                 memcpy(__entry->comm, task->comm, TASK_COMM_LEN);
56                 __entry->pid    = task->pid;
57         ),
58
59         TP_printk("sig=%d errno=%d code=%d comm=%s pid=%d",
60                   __entry->sig, __entry->errno, __entry->code,
61                   __entry->comm, __entry->pid)
62 );
63
64 /**
65  * signal_deliver - called when a signal is delivered
66  * @sig: signal number
67  * @info: pointer to struct siginfo
68  * @ka: pointer to struct k_sigaction
69  *
70  * A 'sig' signal is delivered to current process with 'info' siginfo,
71  * and it will be handled by 'ka'. ka->sa.sa_handler can be SIG_IGN or
72  * SIG_DFL.
73  * Note that some signals reported by signal_generate tracepoint can be
74  * lost, ignored or modified (by debugger) before hitting this tracepoint.
75  * This means, this can show which signals are actually delivered, but
76  * matching generated signals and delivered signals may not be correct.
77  */
78 TRACE_EVENT(signal_deliver,
79
80         TP_PROTO(int sig, struct siginfo *info, struct k_sigaction *ka),
81
82         TP_ARGS(sig, info, ka),
83
84         TP_STRUCT__entry(
85                 __field(        int,            sig             )
86                 __field(        int,            errno           )
87                 __field(        int,            code            )
88                 __field(        unsigned long,  sa_handler      )
89                 __field(        unsigned long,  sa_flags        )
90         ),
91
92         TP_fast_assign(
93                 __entry->sig    = sig;
94                 TP_STORE_SIGINFO(__entry, info);
95                 __entry->sa_handler     = (unsigned long)ka->sa.sa_handler;
96                 __entry->sa_flags       = ka->sa.sa_flags;
97         ),
98
99         TP_printk("sig=%d errno=%d code=%d sa_handler=%lx sa_flags=%lx",
100                   __entry->sig, __entry->errno, __entry->code,
101                   __entry->sa_handler, __entry->sa_flags)
102 );
103
104 DECLARE_EVENT_CLASS(signal_queue_overflow,
105
106         TP_PROTO(int sig, int group, struct siginfo *info),
107
108         TP_ARGS(sig, group, info),
109
110         TP_STRUCT__entry(
111                 __field(        int,    sig     )
112                 __field(        int,    group   )
113                 __field(        int,    errno   )
114                 __field(        int,    code    )
115         ),
116
117         TP_fast_assign(
118                 __entry->sig    = sig;
119                 __entry->group  = group;
120                 TP_STORE_SIGINFO(__entry, info);
121         ),
122
123         TP_printk("sig=%d group=%d errno=%d code=%d",
124                   __entry->sig, __entry->group, __entry->errno, __entry->code)
125 );
126
127 /**
128  * signal_overflow_fail - called when signal queue is overflow
129  * @sig: signal number
130  * @group: signal to process group or not (bool)
131  * @info: pointer to struct siginfo
132  *
133  * Kernel fails to generate 'sig' signal with 'info' siginfo, because
134  * siginfo queue is overflow, and the signal is dropped.
135  * 'group' is not 0 if the signal will be sent to a process group.
136  * 'sig' is always one of RT signals.
137  */
138 DEFINE_EVENT(signal_queue_overflow, signal_overflow_fail,
139
140         TP_PROTO(int sig, int group, struct siginfo *info),
141
142         TP_ARGS(sig, group, info)
143 );
144
145 /**
146  * signal_lose_info - called when siginfo is lost
147  * @sig: signal number
148  * @group: signal to process group or not (bool)
149  * @info: pointer to struct siginfo
150  *
151  * Kernel generates 'sig' signal but loses 'info' siginfo, because siginfo
152  * queue is overflow.
153  * 'group' is not 0 if the signal will be sent to a process group.
154  * 'sig' is always one of non-RT signals.
155  */
156 DEFINE_EVENT(signal_queue_overflow, signal_lose_info,
157
158         TP_PROTO(int sig, int group, struct siginfo *info),
159
160         TP_ARGS(sig, group, info)
161 );
162
163 #endif /* _TRACE_SIGNAL_H */
164
165 /* This part must be outside protection */
166 #include <trace/define_trace.h>