1TAPSET::SIGNAL(3stap) TAPSET::SIGNAL(3stap)
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6 tapset::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 successfully 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 successfully added
81 into the sigqueue of receiving process or a SI_TIMER
82 entry is already queued so just increment the overrun
83 count
84 - return 1 if this signal is ignored by receiving process
86 Return values for "send_sigqueue"
88 - return 0 if the signal is either successfully added
90 into the sigqueue of receiving process or a SI_TIMER
91 entry is already queued so just increment the overrun
92 count
93 - return 1 if this signal is ignored by receiving process
95 - return -1 if the task is marked exiting, so
97 posix_timer_event can redirect it to the group leader
98 shared
100 indicates whether this signal is shared by the thread group
101 send2queue
103 indicates whether this signal is sent to an existing sigqueue
104 name
106 name of the function used to send out this signal
107 signal.checkperm
111 Fires when check permissions for sending the signal
113 Arguments:
115 sig
117 the number of the signal
118 sig_name
120 a string representation of the signal
121 sig_pid
123 pid of the signal recipient process
124 pid_name
126 name of the signal recipient process
127 si_code
129 indicates the signal type
130 task
132 a task handle to the signal recipient
133 sinfo
135 the address of siginfo struct
136 name
138 name of the probe point, is set to "signal.checkperm"
139 signal.checkperm.return
142 Fires when return from permissions check for sending a signal
144 Arguments:
146 retstr
148 the return value
149 name
151 name of the probe point, is set to "signal.checkperm"
152 signal.wakeup
155 Fires when wake up the process for new active signals
157 Arguments:
159 sig_pid
161 pid of the process to be woke up
162 pid_name
164 name of the process to be woke up
165 resume
167 indicate whether to wake up a task in STOPPED or TRACED state
168 state_mask
170 a string representation indicate the mask of task states that
171 can be woken. Possible values are (TASK_INTERRUPT‐
172 IBLE|TASK_STOPPED|TASK_TRACED) and TASK_INTERRUPTIBLE.
173 signal.check_ignored
176 Fires when check whether the signal is ignored or not
178 Arguments:
180 sig_pid
182 pid of the signal recipient process
183 pid_name
185 name of the signal recipient process
186 sig
188 the signal to be checked
189 sig_name
191 name of the signal
192 signal.check_ignored.return
195 Fires when return from signal.check_ignored
197 Arguments:
199 retstr
201 return value. 0 indicate the current signal isn't ignored.
202 signal.force_segv
205 Forces SIGSEGV when there are some issues while handling signals
207 for the process
208 Arguments:
210 sig_pid
212 pid of the signal recipient process
213 pid_name
215 name of the signal recipient process
216 sig
218 the signal being handled
219 sig_name
221 name of this signal
222 signal.force_segv.return
225 Fires when return from signal.force_segv
227 Arguments:
229 retstr
231 return value. Always return 0
232 signal.syskill
235 Fires when sys_kill is called to send a signal to a process.
237 Arguments:
239 pid
241 pid of the recipient process
242 sig
244 the signal to be sent
245 signal.syskill.return
248 Fires when returning from sys_kill
250 signal.tgkill
253 Fires when sys_tgkill is called to send a signal to one specific
255 thread
256 Arguments:
258 pid
260 pid of the recipient thread
261 tgid
263 thread group id which the target thread should have
264 sig
266 the signal to be sent
267 signal.tgkill.return
270 Fires when returning from sys_tgkill
272 signal.tkill
275 Fires when sys_tkill is called to send a signal to a single
277 process.
278 Arguments:
280 pid
282 pid of the recipient process
283 sig
285 the signal to be sent
286 signal.tkill.return
289 Fires when returning from sys_tkill
291 signal.send_sig_queue
294 Fires when queue a signal to a process
296 Arguments:
298 sig
300 the signal to be queued
301 sig_name
303 name of this signal
304 sig_pid
306 pid of the process to which the signal is queued
307 pid_name
309 name of the process to which the signal is queued
310 sigqueue_addr
312 address of the signal queue
313 signal.send_sig_queue.return
316 Fires when return from signal.send_sig_queue
318 Arguments:
320 retstr
322 return value
323 signal.pending
326 Fires when examine the set of signals that are pending for
328 delivery to the calling thread
329 Arguments:
331 sigset_add
333 address of user space sigset_t
334 sigset_size
336 sigset size
337 signal.pending.return
340 Fires when return from signal.pending
342 Arguments:
344 retstr
346 return value
347 signal.handle
350 Fires when invoking the signal handler
352 Arguments:
354 sig
356 signal number
357 sig_name
359 signal name
360 sinfo
362 address of siginfo struct
363 sig_code
365 the si_code of siginfo
366 ka_addr
368 Address of the k_sigaction struct associated with the signal
369 oldset_addr
371 Address of a bit mask array of blocked signals
372 sig_mode
374 indicates whether the signal is a User Mode or Kernel mode
375 Signal
376 signal.handle.return
379 Fires when return from signal.handle
381 Arguments:
383 retstr
385 return value of handle_signal()
386 signal.do_action
389 Fires by calling thread to examine and change a signal action
391 Arguments:
393 sig
395 signal number
396 sigact_addr
398 address of the new sigaction struct associated with the signal
399 oldsigact_addr
401 address of a previous sigaction struct associated with the
402 signal
403 sa_handler
405 the new handler of the signal
406 sa_mask
408 the new mask of the signal
409 signal.do_action.return
412 Fires when return from signal.do_action
414 Arguments:
416 retstr
418 return value of do_sigaction()
419 signal.procmask
422 Fires by calling thread to examine and change blocked signals
424 Arguments:
426 how
428 indicates how to change the blocked signals.
429 Possible values are:
430 SIG_BLOCK=0 for blocking signals
431 SIG_UNBLOCK=1 for unblocking signals
432 SIG_SETMASK=2 for setting the signal mask
433 sigset_addr
435 address of sigset_t to be set
436 oldsigset_addr
438 address of the old sigset_t
439 sigset
441 the actual sigset to be set
442 signal.procmask.return
445 Fires when return from signal.procmask
447 Arguments:
449 retstr
451 return value of sigprocmask()
452 signal.flush
455 Fires when flush all pending signals for a task
457 Arguments:
459 task
461 the task handler of the process
462 sig_pid
464 pid of the task
465 pid_name
467 name of the task
468
471 stap(1), stapprobes(3stap)
472IBM TAPSET::SIGNAL(3stap)