1STAPPROBES.SIGNAL(5) File Formats Manual STAPPROBES.SIGNAL(5)
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6 stapprobes.signal - systemtap signal probe points
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11 This family of probe points is used to probe signal activities. It
12 contains the following probe points:
13 signal.send
16 Fires when a signal is sent to a process
18 Arguments:
20 sig
22 signal number
23 sig_name
25 a string representation of the signal
26 sig_pid
28 pid of the signal recipient process
29 pid_name
31 name of the signal recipient process
32 si_code
34 indicates the signal type
35 task
37 a task handle to the signal recipient
38 sinfo
40 the address of siginfo struct
41 shared
43 indicates whether this signal is shared by the thread group
44 send2queue
46 indicates whether this signal is sent to an existing sigqueue
47 name
49 name of the function used to send out this signal
50 signal.send.return
53 Fires when return from sending a signal
55 Arguments:
57 retstr
59 the return value
60 Return values for "__group_send_sig_info" and "spe‐
62 cific_send_sig_info"
63 - return 0 if the signal is sucessfully sent to a
65 process, which means the following:
66 <1> the signal is ignored by receiving process
68 <2> this is a non-RT signal and we already have one
70 queued
71 <3> the signal is successfully added into the sigqueue of
73 receiving process
74 - return -EAGAIN if the sigqueue is overflow the signal
76 was RT and sent by user using something other than kill()
77 Return values for "send_group_sigqueue"
79 - return 0 if the signal is either sucessfully added into
81 the sigqueue of receiving process or a SI_TIMER entry is
82 already queued so just increment the overrun count
83 - return 1 if this signal is ignored by receiving process
85 Return values for "send_sigqueue"
87 - return 0 if the signal is either sucessfully added into
89 the sigqueue of receiving process or a SI_TIMER entry is
90 already queued so just increment the overrun count
91 - return 1 if this signal is ignored by receiving process
93 - return -1 if the task is marked exiting, so
95 posix_timer_event can redirect it to the group leader
96 shared
98 indicates whether this signal is shared by the thread group
99 send2queue
101 indicates whether this signal is sent to an existing sigqueue
102 name
104 name of the function used to send out this signal
105 signal.checkperm
109 Fires when check permissions for sending the signal
111 Arguments:
113 sig
115 the number of the signal
116 sig_name
118 a string representation of the signal
119 sig_pid
121 pid of the signal recipient process
122 pid_name
124 name of the signal recipient process
125 si_code
127 indicates the signal type
128 task
130 a task handle to the signal recipient
131 sinfo
133 the address of siginfo struct
134 name
136 name of the probe point, is set to "signal.checkperm"
137 signal.checkperm.return
140 Fires when return from permissions check for sending a signal
142 Arguments:
144 retstr
146 the return value
147 name
149 name of the probe point, is set to "signal.checkperm"
150 signal.wakeup
153 Fires when wake up the process for new active signals
155 Arguments:
157 sig_pid
159 pid of the process to be woke up
160 pid_name
162 name of the process to be woke up
163 resume
165 indicate whether to wake up a task in STOPPED or TRACED state
166 state_mask
168 a string representation indicate the mask of task states that
169 can be woken. Possible values are (TASK_INTERRUPT‐
170 IBLE|TASK_STOPPED|TASK_TRACED) and TASK_INTERRUPTIBLE.
171 signal.check_ignored
174 Fires when check whether the signal is ignored or not
176 Arguments:
178 sig_pid
180 pid of the signal recipient process
181 pid_name
183 name of the signal recipient process
184 sig
186 the signal to be checked
187 sig_name
189 name of the signal
190 signal.check_ignored.return
193 Fires when return from signal.check_ignored
195 Arguments:
197 retstr
199 return value. 0 indicate the current signal isn't ignored.
200 signal.force_segv
203 Forces SIGSEGV when there are some issues while handling signals
205 for the process
206 Arguments:
208 sig_pid
210 pid of the signal recipient process
211 pid_name
213 name of the signal recipient process
214 sig
216 the signal being handled
217 sig_name
219 name of this signal
220 signal.force_segv.return
223 Fires when return from signal.force_segv
225 Arguments:
227 retstr
229 return value. Always return 0
230 signal.syskill
233 Fires when sys_kill is called to send a signal to a process.
235 Arguments:
237 pid
239 pid of the recipient process
240 sig
242 the signal to be sent
243 signal.syskill.return
246 Fires when returning from sys_kill
248 signal.tgkill
251 Fires when sys_tgkill is called to send a signal to one specific
253 thread
254 Arguments:
256 pid
258 pid of the recipient thread
259 tgid
261 thread group id which the target thread should have
262 sig
264 the signal to be sent
265 signal.tgkill.return
268 Fires when returning from sys_tgkill
270 signal.tkill
273 Fires when sys_tkill is called to send a signal to a single
275 process.
276 Arguments:
278 pid
280 pid of the recipient process
281 sig
283 the signal to be sent
284 signal.tkill.return
287 Fires when returning from sys_tkill
289 signal.send_sig_queue
292 Fires when queue a signal to a process
294 Arguments:
296 sig
298 the signal to be queued
299 sig_name
301 name of this signal
302 sig_pid
304 pid of the process to which the signal is queued
305 pid_name
307 name of the process to which the signal is queued
308 sigqueue_addr
310 address of the signal queue
311 signal.send_sig_queue.return
314 Fires when return from signal.send_sig_queue
316 Arguments:
318 retstr
320 return value
321 signal.pending
324 Fires when examine the set of signals that are pending for
326 delivery to the calling thread
327 Arguments:
329 sigset_add
331 address of user space sigset_t
332 sigset_size
334 sigset size
335 signal.pending.return
338 Fires when return from signal.pending
340 Arguments:
342 retstr
344 return value
345 signal.handle
348 Fires when invoking the signal handler
350 Arguments:
352 sig
354 signal number
355 sig_name
357 signal name
358 sinfo
360 address of siginfo struct
361 sig_code
363 the si_code of siginfo
364 ka_addr
366 Address of the k_sigaction struct associated with the signal
367 oldset_addr
369 Address of a bit mask array of blocked signals
370 sig_mode
372 indicates whether the signal is a User Mode or Kernel mode
373 Signal
374 signal.handle.return
377 Fires when return from signal.handle
379 Arguments:
381 retstr
383 return value of handle_signal()
384 signal.do_action
387 Fires by calling thread to examine and change a signal action
389 Arguments:
391 sig
393 signal number
394 sigact_addr
396 address of the new sigaction struct associated with the signal
397 oldsigact_addr
399 address of a previous sigaction struct associated with the
400 signal
401 sa_handler
403 the new handler of the signal
404 sa_mask
406 the new mask of the signal
407 signal.do_action.return
410 Fires when return from signal.do_action
412 Arguments:
414 retstr
416 return value of do_sigaction()
417 signal.procmask
420 Fires by calling thread to examine and change blocked signals
422 Arguments:
424 how
426 indicates how to change the blocked signals.
427 Possible values are:
428 SIG_BLOCK=0 for blocking signals
429 SIG_UNBLOCK=1 for unblocking signals
430 SIG_SETMASK=2 for setting the signal mask
431 sigset_addr
433 address of sigset_t to be set
434 oldsigset_addr
436 address of the old sigset_t
437 sigset
439 the actual sigset to be set
440 signal.procmask.return
443 Fires when return from signal.procmask
445 Arguments:
447 retstr
449 return value of sigprocmask()
450 signal.flush
453 Fires when flush all pending signals for a task
455 Arguments:
457 task
459 the task handler of the process
460 sig_pid
462 pid of the task
463 pid_name
465 name of the task
466
469 stap(1), stapprobes(5),
470IBM 2008-03-27 STAPPROBES.SIGNAL(5)