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8 .TH PROC 4 "Jul 23, 2015"
9 .SH NAME
10 proc \- /proc, the process file system
11 .SH DESCRIPTION
12 .LP
13 \fB/proc\fR is a file system that provides access to the state of each process
14 and light-weight process (lwp) in the system. The name of each entry in the
15 \fB/proc\fR directory is a decimal number corresponding to a process-ID. These
16 entries are themselves subdirectories. Access to process state is provided by
17 additional files contained within each subdirectory; the hierarchy is described
18 more completely below. In this document, ``\fB/proc\fR file'' refers to a
19 non-directory file within the hierarchy rooted at \fB/proc\fR. The owner of
20 each \fB/proc\fR file and subdirectory is determined by the user-ID of the
21 process.
22 .sp
23 .LP
24 \fB/proc\fR can be mounted on any mount point, in addition to the standard
25 \fB/proc\fR mount point, and can be mounted several places at once. Such
26 additional mounts are allowed in order to facilitate the confinement of
27 processes to subtrees of the file system via \fBchroot\fR(1M) and yet allow
28 such processes access to commands like \fBps\fR(1).
29 .sp
30 .LP
31 Standard system calls are used to access \fB/proc\fR files: \fBopen\fR(2),
32 \fBclose\fR(2), \fBread\fR(2), and \fBwrite\fR(2) (including \fBreadv\fR(2),
33 \fBwritev\fR(2), \fBpread\fR(2), and \fBpwrite\fR(2)). Most files describe
34 process state and can only be opened for reading. \fBctl\fR and \fBlwpctl\fR
35 (control) files permit manipulation of process state and can only be opened for
36 writing. \fBas\fR (address space) files contain the image of the running
37 process and can be opened for both reading and writing. An open for writing
38 allows process control; a read-only open allows inspection but not control. In
39 this document, we refer to the process as open for reading or writing if any of
40 its associated \fB/proc\fR files is open for reading or writing.
41 .sp
42 .LP
43 In general, more than one process can open the same \fB/proc\fR file at the
44 same time. \fIExclusive\fR \fIopen\fR is an advisory mechanism provided to
45 allow controlling processes to avoid collisions with each other. A process can
46 obtain exclusive control of a target process, with respect to other cooperating
47 processes, if it successfully opens any \fB/proc\fR file in the target process
48 for writing (the \fBas\fR or \fBctl\fR files, or the \fBlwpctl\fR file of any
49 lwp) while specifying \fBO_EXCL\fR in the \fBopen\fR(2). Such an open will fail
50 if the target process is already open for writing (that is, if an \fBas\fR,
51 \fBctl\fR, or \fBlwpctl\fR file is already open for writing). There can be any
52 number of concurrent read-only opens; \fBO_EXCL\fR is ignored on opens for
53 reading. It is recommended that the first open for writing by a controlling
54 process use the \fBO_EXCL\fR flag; multiple controlling processes usually
55 result in chaos.
56 .sp
57 .LP
58 If a process opens one of its own \fB/proc\fR files for writing, the open
59 succeeds regardless of \fBO_EXCL\fR and regardless of whether some other
60 process has the process open for writing. Self-opens do not count when another
61 process attempts an exclusive open. (A process cannot exclude a debugger by
62 opening itself for writing and the application of a debugger cannot prevent a
63 process from opening itself.) All self-opens for writing are forced to be
64 close-on-exec (see the \fBF_SETFD\fR operation of \fBfcntl\fR(2)).
65 .sp
66 .LP
67 Data may be transferred from or to any locations in the address space of the
68 traced process by applying \fBlseek\fR(2) to position the \fBas\fR file at the
69 virtual address of interest followed by \fBread\fR(2) or \fBwrite\fR(2) (or by
70 using \fBpread\fR(2) or \fBpwrite\fR(2) for the combined operation). The
71 address-map files \fB/proc/\fR\fIpid\fR\fB/map\fR and
72 \fB/proc/\fR\fIpid\fR\fB/xmap\fR can be read to determine the accessible areas
73 (mappings) of the address space. \fBI/O\fR transfers may span contiguous
74 mappings. An \fBI/O\fR request extending into an unmapped area is truncated at
75 the boundary. A write request beginning at an unmapped virtual address fails
76 with \fBEIO\fR; a read request beginning at an unmapped virtual address returns
77 zero (an end-of-file indication).
78 .sp
79 .LP
80 Information and control operations are provided through additional files.
81 \fB<procfs.h>\fR contains definitions of data structures and message formats
82 used with these files. Some of these definitions involve the use of sets of
83 flags. The set types \fBsigset_t\fR, \fBfltset_t\fR, and \fBsysset_t\fR
84 correspond, respectively, to signal, fault, and system call enumerations
85 defined in \fB<sys/signal.h>\fR, \fB<sys/fault.h>\fR, and
86 \fB<sys/syscall.h>\fR\&. Each set type is large enough to hold flags for its
87 own enumeration. Although they are of different sizes, they have a common
88 structure and can be manipulated by these macros:
89 .sp
90 .in +2
91 .nf
92 prfillset(&set); /* turn on all flags in set */
93 premptyset(&set); /* turn off all flags in set */
94 praddset(&set, flag); /* turn on the specified flag */
95 prdelset(&set, flag); /* turn off the specified flag */
96 r = prismember(&set, flag); /* != 0 iff flag is turned on */
97 .fi
98 .in -2
99
100 .sp
101 .LP
102 One of \fBprfillset()\fR or \fBpremptyset()\fR must be used to initialize
103 \fBset\fR before it is used in any other operation. \fBflag\fR must be a member
104 of the enumeration corresponding to \fBset\fR.
105 .sp
106 .LP
107 Every process contains at least one \fIlight-weight process\fR, or \fIlwp\fR.
108 Each lwp represents a flow of execution that is independently scheduled by the
109 operating system. All lwps in a process share its address space as well as many
110 other attributes. Through the use of \fBlwpctl\fR and \fBctl\fR files as
111 described below, it is possible to affect individual lwps in a process or to
112 affect all of them at once, depending on the operation.
113 .sp
114 .LP
115 When the process has more than one lwp, a representative lwp is chosen by the
116 system for certain process status files and control operations. The
117 representative lwp is a stopped lwp only if all of the process's lwps are
118 stopped; is stopped on an event of interest only if all of the lwps are so
119 stopped (excluding \fBPR_SUSPENDED\fR lwps); is in a \fBPR_REQUESTED\fR stop
120 only if there are no other events of interest to be found; or, failing
121 everything else, is in a \fBPR_SUSPENDED\fR stop (implying that the process is
122 deadlocked). See the description of the \fBstatus\fR file for definitions of
123 stopped states. See the \fBPCSTOP\fR control operation for the definition of
124 ``event of interest''.
125 .sp
126 .LP
127 The representative lwp remains fixed (it will be chosen again on the next
128 operation) as long as all of the lwps are stopped on events of interest or are
129 in a \fBPR_SUSPENDED\fR stop and the \fBPCRUN\fR control operation is not
130 applied to any of them.
131 .sp
132 .LP
133 When applied to the process control file, every \fB/proc\fR control operation
134 that must act on an lwp uses the same algorithm to choose which lwp to act
135 upon. Together with synchronous stopping (see \fBPCSET\fR), this enables a
136 debugger to control a multiple-lwp process using only the process-level status
137 and control files if it so chooses. More fine-grained control can be achieved
138 using the lwp-specific files.
139 .sp
140 .LP
141 The system supports two process data models, the traditional 32-bit data model
142 in which ints, longs and pointers are all 32 bits wide (the ILP32 data model),
143 and on some platforms the 64-bit data model in which longs and pointers, but
144 not ints, are 64 bits in width (the LP64 data model). In the LP64 data model
145 some system data types, notably \fBsize_t\fR, \fBoff_t\fR, \fBtime_t\fR and
146 \fBdev_t\fR, grow from 32 bits to 64 bits as well.
147 .sp
148 .LP
149 The \fB/proc\fR interfaces described here are available to both 32-bit and
150 64-bit controlling processes. However, many operations attempted by a 32-bit
151 controlling process on a 64-bit target process will fail with \fBEOVERFLOW\fR
152 because the address space range of a 32-bit process cannot encompass a 64-bit
153 process or because the data in some 64-bit system data type cannot be
154 compressed to fit into the corresponding 32-bit type without loss of
155 information. Operations that fail in this circumstance include reading and
156 writing the address space, reading the address-map files, and setting the
157 target process's registers. There is no restriction on operations applied by a
158 64-bit process to either a 32-bit or a 64-bit target processes.
159 .sp
160 .LP
161 The format of the contents of any \fB/proc\fR file depends on the data model of
162 the observer (the controlling process), not on the data model of the target
163 process. A 64-bit debugger does not have to translate the information it reads
164 from a \fB/proc\fR file for a 32-bit process from 32-bit format to 64-bit
165 format. However, it usually has to be aware of the data model of the target
166 process. The \fBpr_dmodel\fR field of the \fBstatus\fR files indicates the
167 target process's data model.
168 .sp
169 .LP
170 To help deal with system data structures that are read from 32-bit processes, a
171 64-bit controlling program can be compiled with the C preprocessor symbol
172 \fB_SYSCALL32\fR defined before system header files are included. This makes
173 explicit 32-bit fixed-width data structures (like \fBcstruct stat32\fR) visible
174 to the 64-bit program. See \fBtypes32.h\fR(3HEAD).
175 .SH DIRECTORY STRUCTURE
176 .LP
177 At the top level, the directory \fB/proc\fR contains entries each of which
178 names an existing process in the system. These entries are themselves
179 directories. Except where otherwise noted, the files described below can be
180 opened for reading only. In addition, if a process becomes a \fIzombie\fR (one
181 that has exited but whose parent has not yet performed a \fBwait\fR(3C) upon
182 it), most of its associated \fB/proc\fR files disappear from the hierarchy;
183 subsequent attempts to open them, or to read or write files opened before the
184 process exited, will elicit the error \fBENOENT\fR.
185 .sp
186 .LP
187 Although process state and consequently the contents of \fB/proc\fR files can
188 change from instant to instant, a single \fBread\fR(2) of a \fB/proc\fR file is
189 guaranteed to return a sane representation of state; that is, the read will be
190 atomic with respect to the state of the process. No such guarantee applies to
191 successive reads applied to a \fB/proc\fR file for a running process. In
192 addition, atomicity is not guaranteed for \fBI/O\fR applied to the \fBas\fR
193 (address-space) file for a running process or for a process whose address space
194 contains memory shared by another running process.
195 .sp
196 .LP
197 A number of structure definitions are used to describe the files. These
198 structures may grow by the addition of elements at the end in future releases
199 of the system and it is not legitimate for a program to assume that they will
200 not.
201 .SH STRUCTURE OF \fB/proc/\fR\fIpid\fR
202 .LP
203 A given directory \fB/proc/\fR\fIpid\fR contains the following entries. A
204 process can use the invisible alias \fB/proc/self\fR if it wishes to open one
205 of its own \fB/proc\fR files (invisible in the sense that the name ``self''
206 does not appear in a directory listing of \fB/proc\fR obtained from
207 \fBls\fR(1), \fBgetdents\fR(2), or \fBreaddir\fR(3C)).
208 .SS "contracts"
209 .LP
210 A directory containing references to the contracts held by the process. Each
211 entry is a symlink to the contract's directory under \fB/system/contract\fR.
212 See \fBcontract\fR(4).
213 .SS "as"
214 .LP
215 Contains the address-space image of the process; it can be opened for both
216 reading and writing. \fBlseek\fR(2) is used to position the file at the virtual
217 address of interest and then the address space can be examined or changed
218 through \fBread\fR(2) or \fBwrite\fR(2) (or by using \fBpread\fR(2) or
219 \fBpwrite\fR(2) for the combined operation).
220 .SS "ctl"
221 .LP
222 A write-only file to which structured messages are written directing the system
223 to change some aspect of the process's state or control its behavior in some
224 way. The seek offset is not relevant when writing to this file. Individual lwps
225 also have associated \fBlwpctl\fR files in the lwp subdirectories. A control
226 message may be written either to the process's \fBctl\fR file or to a specific
227 \fBlwpctl\fR file with operation-specific effects. The effect of a control
228 message is immediately reflected in the state of the process visible through
229 appropriate status and information files. The types of control messages are
230 described in detail later. See \fBCONTROL MESSAGES\fR.
231 .SS "status"
232 .LP
233 Contains state information about the process and the representative lwp. The
234 file contains a \fBpstatus\fR structure which contains an embedded
235 \fBlwpstatus\fR structure for the representative lwp, as follows:
236 .sp
237 .in +2
238 .nf
239 typedef struct pstatus {
240 int pr_flags; /* flags (see below) */
241 int pr_nlwp; /* number of active lwps in the process */
242 int pr_nzomb; /* number of zombie lwps in the process */
243 pid_tpr_pid; /* process id */
244 pid_tpr_ppid; /* parent process id */
245 pid_tpr_pgid; /* process group id */
246 pid_tpr_sid; /* session id */
247 id_t pr_aslwpid; /* obsolete */
248 id_t pr_agentid; /* lwp-id of the agent lwp, if any */
249 sigset_t pr_sigpend; /* set of process pending signals */
250 uintptr_t pr_brkbase; /* virtual address of the process heap */
251 size_t pr_brksize; /* size of the process heap, in bytes */
252 uintptr_t pr_stkbase; /* virtual address of the process stack */
253 size_tpr_stksize; /* size of the process stack, in bytes */
254 timestruc_t pr_utime; /* process user cpu time */
255 timestruc_t pr_stime; /* process system cpu time */
256 timestruc_t pr_cutime; /* sum of children's user times */
257 timestruc_t pr_cstime; /* sum of children's system times */
258 sigset_t pr_sigtrace; /* set of traced signals */
259 fltset_t pr_flttrace; /* set of traced faults */
260 sysset_t pr_sysentry; /* set of system calls traced on entry */
261 sysset_t pr_sysexit; /* set of system calls traced on exit */
262 char pr_dmodel; /* data model of the process */
263 taskid_t pr_taskid; /* task id */
264 projid_t pr_projid; /* project id */
265 zoneid_t pr_zoneid; /* zone id */
266 lwpstatus_t pr_lwp; /* status of the representative lwp */
267 } pstatus_t;
268 .fi
269 .in -2
270
271 .sp
272 .LP
273 \fBpr_flags\fR is a bit-mask holding the following process flags. For
274 convenience, it also contains the lwp flags for the representative lwp,
275 described later.
276 .sp
277 .ne 2
278 .na
279 \fB\fBPR_ISSYS\fR\fR
280 .ad
281 .RS 13n
282 process is a system process (see \fBPCSTOP\fR).
283 .RE
284
285 .sp
286 .ne 2
287 .na
288 \fB\fBPR_VFORKP\fR\fR
289 .ad
290 .RS 13n
291 process is the parent of a vforked child (see \fBPCWATCH\fR).
292 .RE
293
294 .sp
295 .ne 2
296 .na
297 \fB\fBPR_FORK\fR\fR
298 .ad
299 .RS 13n
300 process has its inherit-on-fork mode set (see \fBPCSET\fR).
301 .RE
302
303 .sp
304 .ne 2
305 .na
306 \fB\fBPR_RLC\fR\fR
307 .ad
308 .RS 13n
309 process has its run-on-last-close mode set (see \fBPCSET\fR).
310 .RE
311
312 .sp
313 .ne 2
314 .na
315 \fB\fBPR_KLC\fR\fR
316 .ad
317 .RS 13n
318 process has its kill-on-last-close mode set (see \fBPCSET\fR).
319 .RE
320
321 .sp
322 .ne 2
323 .na
324 \fB\fBPR_ASYNC\fR\fR
325 .ad
326 .RS 13n
327 process has its asynchronous-stop mode set (see \fBPCSET\fR).
328 .RE
329
330 .sp
331 .ne 2
332 .na
333 \fB\fBPR_MSACCT\fR\fR
334 .ad
335 .RS 13n
336 Set by default in all processes to indicate that microstate accounting is
337 enabled. However, this flag has been deprecated and no longer has any effect.
338 Microstate accounting may not be disabled; however, it is still possible to
339 toggle the flag.
340 .RE
341
342 .sp
343 .ne 2
344 .na
345 \fB\fBPR_MSFORK\fR\fR
346 .ad
347 .RS 13n
348 Set by default in all processes to indicate that microstate accounting will be
349 enabled for processes that this parent forks(). However, this flag has been
350 deprecated and no longer has any effect. It is possible to toggle this flag;
351 however, it is not possible to disable microstate accounting.
352 .RE
353
354 .sp
355 .ne 2
356 .na
357 \fB\fBPR_BPTADJ\fR\fR
358 .ad
359 .RS 13n
360 process has its breakpoint adjustment mode set (see \fBPCSET\fR).
361 .RE
362
363 .sp
364 .ne 2
365 .na
366 \fB\fBPR_PTRACE\fR\fR
367 .ad
368 .RS 13n
369 process has its ptrace-compatibility mode set (see \fBPCSET\fR).
370 .RE
371
372 .sp
373 .LP
374 \fBpr_nlwp\fR is the total number of active lwps in the process. pr_nzomb is
375 the total number of zombie lwps in the process. A zombie lwp is a non-detached
376 lwp that has terminated but has not been reaped with \fBthr_join\fR(3C) or
377 \fBpthread_join\fR(3C).
378 .sp
379 .LP
380 \fBpr_pid\fR, \fBpr_ppid\fR, \fBpr_pgid\fR, and \fBpr_sid\fR are, respectively,
381 the process ID, the ID of the process's parent, the process's process group ID,
382 and the process's session ID.
383 .sp
384 .LP
385 \fBpr_aslwpid\fR is obsolete and is always zero.
386 .sp
387 .LP
388 \fBpr_agentid\fR is the lwp-ID for the \fB/proc\fR agent lwp (see the
389 \fBPCAGENT\fR control operation). It is zero if there is no agent lwp in the
390 process.
391 .sp
392 .LP
393 \fBpr_sigpend\fR identifies asynchronous signals pending for the process.
394 .sp
395 .LP
396 \fBpr_brkbase\fR is the virtual address of the process heap and
397 \fBpr_brksize\fR is its size in bytes. The address formed by the sum of these
398 values is the process \fBbreak\fR (see \fBbrk\fR(2)). \fBpr_stkbase\fR and
399 \fBpr_stksize\fR are, respectively, the virtual address of the process stack
400 and its size in bytes. (Each lwp runs on a separate stack; the distinguishing
401 characteristic of the process stack is that the operating system will grow it
402 when necessary.)
403 .sp
404 .LP
405 \fBpr_utime\fR, \fBpr_stime\fR, \fBpr_cutime\fR, and \fBpr_cstime\fR are,
406 respectively, the user \fBCPU\fR and system \fBCPU\fR time consumed by the
407 process, and the cumulative user \fBCPU\fR and system \fBCPU\fR time consumed
408 by the process's children, in seconds and nanoseconds.
409 .sp
410 .LP
411 \fBpr_sigtrace\fR and \fBpr_flttrace\fR contain, respectively, the set of
412 signals and the set of hardware faults that are being traced (see
413 \fBPCSTRACE\fR and \fBPCSFAULT\fR).
414 .sp
415 .LP
416 \fBpr_sysentry\fR and \fBpr_sysexit\fR contain, respectively, the sets of
417 system calls being traced on entry and exit (see \fBPCSENTRY\fR and
418 \fBPCSEXIT\fR).
419 .sp
420 .LP
421 \fBpr_dmodel\fR indicates the data model of the process. Possible values are:
422 .sp
423 .ne 2
424 .na
425 \fB\fBPR_MODEL_ILP32\fR\fR
426 .ad
427 .RS 19n
428 process data model is ILP32.
429 .RE
430
431 .sp
432 .ne 2
433 .na
434 \fB\fBPR_MODEL_LP64\fR\fR
435 .ad
436 .RS 19n
437 process data model is LP64.
438 .RE
439
440 .sp
441 .ne 2
442 .na
443 \fB\fBPR_MODEL_NATIVE\fR\fR
444 .ad
445 .RS 19n
446 process data model is native.
447 .RE
448
449 .sp
450 .LP
451 The \fBpr_taskid\fR, \fBpr_projid\fR, and \fBpr_zoneid\fR fields contain
452 respectively, the numeric \fBID\fRs of the task, project, and zone in which the
453 process was running.
454 .sp
455 .LP
456 The constant \fBPR_MODEL_NATIVE\fR reflects the data model of the controlling
457 process, \fIthat is\fR, its value is \fBPR_MODEL_ILP32\fR or
458 \fBPR_MODEL_LP64\fR according to whether the controlling process has been
459 compiled as a 32-bit program or a 64-bit program, respectively.
460 .sp
461 .LP
462 \fBpr_lwp\fR contains the status information for the representative lwp:
463 .sp
464 .in +2
465 .nf
466 typedef struct lwpstatus {
467 int pr_flags; /* flags (see below) */
468 id_t pr_lwpid; /* specific lwp identifier */
469 short pr_why; /* reason for lwp stop, if stopped */
470 short pr_what; /* more detailed reason */
471 short pr_cursig; /* current signal, if any */
472 siginfo_t pr_info; /* info associated with signal or fault */
473 sigset_t pr_lwppend; /* set of signals pending to the lwp */
474 sigset_t pr_lwphold; /* set of signals blocked by the lwp */
475 struct sigaction pr_action;/* signal action for current signal */
476 stack_t pr_altstack; /* alternate signal stack info */
477 uintptr_t pr_oldcontext; /* address of previous ucontext */
478 short pr_syscall; /* system call number (if in syscall) */
479 short pr_nsysarg; /* number of arguments to this syscall */
480 int pr_errno; /* errno for failed syscall */
481 long pr_sysarg[PRSYSARGS]; /* arguments to this syscall */
482 long pr_rval1; /* primary syscall return value */
483 long pr_rval2; /* second syscall return value, if any */
484 char pr_clname[PRCLSZ]; /* scheduling class name */
485 timestruc_t pr_tstamp; /* real-time time stamp of stop */
486 timestruc_t pr_utime; /* lwp user cpu time */
487 timestruc_t pr_stime; /* lwp system cpu time */
488 uintptr_t pr_ustack; /* stack boundary data (stack_t) address */
489 ulong_t pr_instr; /* current instruction */
490 prgregset_t pr_reg; /* general registers */
491 prfpregset_t pr_fpreg; /* floating-point registers */
492 } lwpstatus_t;
493 .fi
494 .in -2
495
496 .sp
497 .LP
498 \fBpr_flags\fR is a bit-mask holding the following lwp flags. For convenience,
499 it also contains the process flags, described previously.
500 .sp
501 .ne 2
502 .na
503 \fB\fBPR_STOPPED\fR\fR
504 .ad
505 .RS 14n
506 The lwp is stopped.
507 .RE
508
509 .sp
510 .ne 2
511 .na
512 \fB\fBPR_ISTOP\fR\fR
513 .ad
514 .RS 14n
515 The lwp is stopped on an event of interest (see \fBPCSTOP\fR).
516 .RE
517
518 .sp
519 .ne 2
520 .na
521 \fB\fBPR_DSTOP\fR\fR
522 .ad
523 .RS 14n
524 The lwp has a stop directive in effect (see \fBPCSTOP\fR).
525 .RE
526
527 .sp
528 .ne 2
529 .na
530 \fB\fBPR_STEP\fR\fR
531 .ad
532 .RS 14n
533 The lwp has a single-step directive in effect (see \fBPCRUN\fR).
534 .RE
535
536 .sp
537 .ne 2
538 .na
539 \fB\fBPR_ASLEEP\fR\fR
540 .ad
541 .RS 14n
542 The lwp is in an interruptible sleep within a system call.
543 .RE
544
545 .sp
546 .ne 2
547 .na
548 \fB\fBPR_PCINVAL\fR\fR
549 .ad
550 .RS 14n
551 The lwp's current instruction (\fBpr_instr\fR) is undefined.
552 .RE
553
554 .sp
555 .ne 2
556 .na
557 \fB\fBPR_DETACH\fR\fR
558 .ad
559 .RS 14n
560 This is a detached lwp (see \fBpthread_create\fR(3C) and
561 \fBpthread_join\fR(3C)).
562 .RE
563
564 .sp
565 .ne 2
566 .na
567 \fB\fBPR_DAEMON\fR\fR
568 .ad
569 .RS 14n
570 This is a daemon lwp (see \fBpthread_create\fR(3C)).
571 .RE
572
573 .sp
574 .ne 2
575 .na
576 \fB\fBPR_ASLWP\fR\fR
577 .ad
578 .RS 14n
579 This flag is obsolete and is never set.
580 .RE
581
582 .sp
583 .ne 2
584 .na
585 \fB\fBPR_AGENT\fR\fR
586 .ad
587 .RS 14n
588 This is the \fB/proc\fR agent lwp for the process.
589 .RE
590
591 .sp
592 .LP
593 \fBpr_lwpid\fR names the specific lwp.
594 .sp
595 .LP
596 \fBpr_why\fR and \fBpr_what\fR together describe, for a stopped lwp, the reason
597 for the stop. Possible values of \fBpr_why\fR and the associated \fBpr_what\fR
598 are:
599 .sp
600 .ne 2
601 .na
602 \fB\fBPR_REQUESTED\fR\fR
603 .ad
604 .RS 17n
605 indicates that the stop occurred in response to a stop directive, normally
606 because \fBPCSTOP\fR was applied or because another lwp stopped on an event of
607 interest and the asynchronous-stop flag (see \fBPCSET\fR) was not set for the
608 process. \fBpr_what\fR is unused in this case.
609 .RE
610
611 .sp
612 .ne 2
613 .na
614 \fB\fBPR_SIGNALLED\fR\fR
615 .ad
616 .RS 17n
617 indicates that the lwp stopped on receipt of a signal (see \fBPCSTRACE\fR);
618 \fBpr_what\fR holds the signal number that caused the stop (for a newly-stopped
619 lwp, the same value is in \fBpr_cursig\fR).
620 .RE
621
622 .sp
623 .ne 2
624 .na
625 \fB\fBPR_FAULTED\fR\fR
626 .ad
627 .RS 17n
628 indicates that the lwp stopped on incurring a hardware fault (see
629 \fBPCSFAULT\fR); \fBpr_what\fR holds the fault number that caused the stop.
630 .RE
631
632 .sp
633 .ne 2
634 .na
635 \fB\fBPR_SYSENTRY\fR\fR
636 .ad
637 .br
638 .na
639 \fB\fBPR_SYSEXIT\fR\fR
640 .ad
641 .RS 17n
642 indicate a stop on entry to or exit from a system call (see \fBPCSENTRY\fR and
643 \fBPCSEXIT\fR); \fBpr_what\fR holds the system call number.
644 .RE
645
646 .sp
647 .ne 2
648 .na
649 \fB\fBPR_JOBCONTROL\fR\fR
650 .ad
651 .RS 17n
652 indicates that the lwp stopped due to the default action of a job control stop
653 signal (see \fBsigaction\fR(2)); \fBpr_what\fR holds the stopping signal
654 number.
655 .RE
656
657 .sp
658 .ne 2
659 .na
660 \fB\fBPR_SUSPENDED\fR\fR
661 .ad
662 .RS 17n
663 indicates that the lwp stopped due to internal synchronization of lwps within
664 the process. \fBpr_what\fR is unused in this case.
665 .RE
666
667 .sp
668 .LP
669 \fBpr_cursig\fR names the current signal, that is, the next signal to be
670 delivered to the lwp, if any. \fBpr_info\fR, when the lwp is in a
671 \fBPR_SIGNALLED\fR or \fBPR_FAULTED\fR stop, contains additional information
672 pertinent to the particular signal or fault (see \fB<sys/siginfo.h>\fR).
673 .sp
674 .LP
675 \fBpr_lwppend\fR identifies any synchronous or directed signals pending for the
676 lwp. \fBpr_lwphold\fR identifies those signals whose delivery is being blocked
677 by the lwp (the signal mask).
678 .sp
679 .LP
680 \fBpr_action\fR contains the signal action information pertaining to the
681 current signal (see \fBsigaction\fR(2)); it is undefined if \fBpr_cursig\fR is
682 zero. \fBpr_altstack\fR contains the alternate signal stack information for the
683 lwp (see \fBsigaltstack\fR(2)).
684 .sp
685 .LP
686 \fBpr_oldcontext\fR, if not zero, contains the address on the lwp stack of a
687 \fBucontext\fR structure describing the previous user-level context (see
688 \fBucontext.h\fR(3HEAD)). It is non-zero only if the lwp is executing in the
689 context of a signal handler.
690 .sp
691 .LP
692 \fBpr_syscall\fR is the number of the system call, if any, being executed by
693 the lwp; it is non-zero if and only if the lwp is stopped on \fBPR_SYSENTRY\fR
694 or \fBPR_SYSEXIT\fR, or is asleep within a system call ( \fBPR_ASLEEP\fR is
695 set). If \fBpr_syscall\fR is non-zero, \fBpr_nsysarg\fR is the number of
696 arguments to the system call and \fBpr_sysarg\fR contains the actual arguments.
697 .sp
698 .LP
699 \fBpr_rval1\fR, \fBpr_rval2\fR, and \fBpr_errno\fR are defined only if the lwp
700 is stopped on \fBPR_SYSEXIT\fR or if the \fBPR_VFORKP\fR flag is set. If
701 \fBpr_errno\fR is zero, \fBpr_rval1\fR and \fBpr_rval2\fR contain the return
702 values from the system call. Otherwise, \fBpr_errno\fR contains the error
703 number for the failing system call (see \fB<sys/errno.h>\fR).
704 .sp
705 .LP
706 \fBpr_clname\fR contains the name of the lwp's scheduling class.
707 .sp
708 .LP
709 \fBpr_tstamp\fR, if the lwp is stopped, contains a time stamp marking when the
710 lwp stopped, in real time seconds and nanoseconds since an arbitrary time in
711 the past.
712 .sp
713 .LP
714 \fBpr_utime\fR is the amount of user level CPU time used by this LWP.
715 .sp
716 .LP
717 \fBpr_stime\fR is the amount of system level CPU time used by this LWP.
718 .sp
719 .LP
720 \fBpr_ustack\fR is the virtual address of the \fBstack_t\fR that contains the
721 stack boundaries for this LWP. See \fBgetustack\fR(2) and
722 \fB_stack_grow\fR(3C).
723 .sp
724 .LP
725 \fBpr_instr\fR contains the machine instruction to which the lwp's program
726 counter refers. The amount of data retrieved from the process is
727 machine-dependent. On SPARC based machines, it is a 32-bit word. On x86-based
728 machines, it is a single byte. In general, the size is that of the machine's
729 smallest instruction. If \fBPR_PCINVAL\fR is set, \fBpr_instr\fR is undefined;
730 this occurs whenever the lwp is not stopped or when the program counter refers
731 to an invalid virtual address.
732 .sp
733 .LP
734 \fBpr_reg\fR is an array holding the contents of a stopped lwp's general
735 registers.
736 .sp
737 .ne 2
738 .na
739 \fBSPARC\fR
740 .ad
741 .RS 21n
742 On SPARC-based machines, the predefined constants \fBR_G0\fR ... \fBR_G7\fR,
743 \fBR_O0\fR ... \fBR_O7\fR, \fBR_L0\fR ... \fBR_L7\fR, \fBR_I0\fR ...
744 \fBR_I7\fR, \fBR_PC\fR, \fBR_nPC\fR, and \fBR_Y\fR can be used as indices to
745 refer to the corresponding registers; previous register windows can be read
746 from their overflow locations on the stack (however, see the \fBgwindows\fR
747 file in the \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwpid\fR subdirectory).
748 .RE
749
750 .sp
751 .ne 2
752 .na
753 \fBSPARC V8 (32-bit)\fR
754 .ad
755 .RS 21n
756 For SPARC V8 (32-bit) controlling processes, the predefined constants
757 \fBR_PSR\fR, \fBR_WIM\fR, and \fBR_TBR\fR can be used as indices to refer to
758 the corresponding special registers. For SPARC V9 (64-bit) controlling
759 processes, the predefined constants \fBR_CCR\fR, \fBR_ASI\fR, and \fBR_FPRS\fR
760 can be used as indices to refer to the corresponding special registers.
761 .RE
762
763 .sp
764 .ne 2
765 .na
766 \fBx86 (32-bit)\fR
767 .ad
768 .RS 21n
769 For 32-bit x86 processes, the predefined constants listed belowcan be used as
770 indices to refer to the corresponding registers.
771 .sp
772 .in +2
773 .nf
774 SS
775 UESP
776 EFL
777 CS
778 EIP
779 ERR
780 TRAPNO
781 EAX
782 ECX
783 EDX
784 EBX
785 ESP
786 EBP
787 ESI
788 EDI
789 DS
790 ES
791 GS
792 .fi
793 .in -2
794
795 The preceding constants are listed in \fB<sys/regset.h>\fR\&.
796 .sp
797 Note that a 32-bit process can run on an x86 64-bit system, using the constants
798 listed above.
799 .RE
800
801 .sp
802 .ne 2
803 .na
804 \fBx86 (64-bit)\fR
805 .ad
806 .RS 21n
807 To read the registers of a 32- \fBor\fR a 64-bit process, a 64-bit x86 process
808 should use the predefined constants listed below.
809 .sp
810 .in +2
811 .nf
812 REG_GSBASE
813 REG_FSBASE
814 REG_DS
815 REG_ES
816 REG_GS
817 REG_FS
818 REG_SS
819 REG_RSP
820 REG_RFL
821 REG_CS
822 REG_RIP
823 REG_ERR
824 REG_TRAPNO
825 REG_RAX
826 REG_RCX
827 REG_RDX
828 REG_RBX
829 REG_RBP
830 REG_RSI
831 REG_RDI
832 REG_R8
833 REG_R9
834 REG_R10
835 REG_R11
836 REG_R12
837 REG_R13
838 REG_R14
839 REG_R15
840 .fi
841 .in -2
842
843 The preceding constants are listed in \fB<sys/regset.h>\fR\&.
844 .RE
845
846 .sp
847 .LP
848 \fBpr_fpreg\fR is a structure holding the contents of the floating-point
849 registers.
850 .sp
851 .LP
852 SPARC registers, both general and floating-point, as seen by a 64-bit
853 controlling process are the V9 versions of the registers, even if the target
854 process is a 32-bit (V8) process. V8 registers are a subset of the V9
855 registers.
856 .sp
857 .LP
858 If the lwp is not stopped, all register values are undefined.
859 .SS "psinfo"
860 .LP
861 Contains miscellaneous information about the process and the representative lwp
862 needed by the \fBps\fR(1) command. \fBpsinfo\fR remains accessible after a
863 process becomes a \fIzombie\fR. The file contains a \fBpsinfo\fR structure
864 which contains an embedded \fBlwpsinfo\fR structure for the representative lwp,
865 as follows:
866 .sp
867 .in +2
868 .nf
869 typedef struct psinfo {
870 int pr_flag; /* process flags (DEPRECATED: see below) */
871 int pr_nlwp; /* number of active lwps in the process */
872 int pr_nzomb; /* number of zombie lwps in the process */
873 pid_t pr_pid; /* process id */
874 pid_t pr_ppid; /* process id of parent */
875 pid_t pr_pgid; /* process id of process group leader */
876 pid_t pr_sid; /* session id */
877 uid_t pr_uid; /* real user id */
878 uid_t pr_euid; /* effective user id */
879 gid_t pr_gid; /* real group id */
880 gid_t pr_egid; /* effective group id */
881 uintptr_t pr_addr; /* address of process */
882 size_t pr_size; /* size of process image in Kbytes */
883 size_t pr_rssize; /* resident set size in Kbytes */
884 dev_t pr_ttydev; /* controlling tty device (or PRNODEV) */
885 ushort_t pr_pctcpu; /* % of recent cpu time used by all lwps */
886 ushort_t pr_pctmem; /* % of system memory used by process */
887 timestruc_t pr_start; /* process start time, from the epoch */
888 timestruc_t pr_time; /* cpu time for this process */
889 timestruc_t pr_ctime; /* cpu time for reaped children */
890 char pr_fname[PRFNSZ]; /* name of exec'ed file */
891 char pr_psargs[PRARGSZ]; /* initial characters of arg list */
892 int pr_wstat; /* if zombie, the wait() status */
893 int pr_argc; /* initial argument count */
894 uintptr_t pr_argv; /* address of initial argument vector */
895 uintptr_t pr_envp; /* address of initial environment vector */
896 char pr_dmodel; /* data model of the process */
897 lwpsinfo_t pr_lwp; /* information for representative lwp */
898 taskid_t pr_taskid; /* task id */
899 projid_t pr_projid; /* project id */
900 poolid_t pr_poolid; /* pool id */
901 zoneid_t pr_zoneid; /* zone id */
902 ctid_t pr_contract; /* process contract id */
903 } psinfo_t;
904 .fi
905 .in -2
906
907 .sp
908 .LP
909 Some of the entries in \fBpsinfo\fR, such as \fBpr_addr\fR, refer to internal
910 kernel data structures and should not be expected to retain their meanings
911 across different versions of the operating system.
912 .sp
913 .LP
914 \fBpsinfo_t.pr_flag\fR is a deprecated interface that should no longer be used.
915 Applications currently relying on the \fBSSYS\fR bit in \fBpr_flag\fR should
916 migrate to checking \fBPR_ISSYS\fR in the \fBpstatus\fR structure's
917 \fBpr_flags\fR field.
918 .sp
919 .LP
920 \fBpr_pctcpu\fR and \fBpr_pctmem\fR are 16-bit binary fractions in the range
921 0.0 to 1.0 with the binary point to the right of the high-order bit (1.0 ==
922 0x8000). \fBpr_pctcpu\fR is the summation over all lwps in the process.
923 .sp
924 .LP
925 \fBpr_lwp\fR contains the \fBps\fR(1) information for the representative lwp.
926 If the process is a \fIzombie\fR, \fBpr_nlwp\fR, \fBpr_nzomb\fR, and
927 \fBpr_lwp.pr_lwpid\fR are zero and the other fields of \fBpr_lwp\fR are
928 undefined:
929 .sp
930 .in +2
931 .nf
932 typedef struct lwpsinfo {
933 int pr_flag; /* lwp flags (DEPRECATED: see below) */
934 id_t pr_lwpid; /* lwp id */
935 uintptr_t pr_addr; /* internal address of lwp */
936 uintptr_t pr_wchan; /* wait addr for sleeping lwp */
937 char pr_stype; /* synchronization event type */
938 char pr_state; /* numeric lwp state */
939 char pr_sname; /* printable character for pr_state */
940 char pr_nice; /* nice for cpu usage */
941 short pr_syscall; /* system call number (if in syscall) */
942 char pr_oldpri; /* pre-SVR4, low value is high priority */
943 char pr_cpu; /* pre-SVR4, cpu usage for scheduling */
944 int pr_pri; /* priority, high value = high priority */
945 ushort_t pr_pctcpu; /* % of recent cpu time used by this lwp */
946 timestruc_t pr_start; /* lwp start time, from the epoch */
947 timestruc_t pr_time; /* cpu time for this lwp */
948 char pr_clname[PRCLSZ]; /* scheduling class name */
949 char pr_name[PRFNSZ]; /* name of system lwp */
950 processorid_t pr_onpro; /* processor which last ran this lwp */
951 processorid_t pr_bindpro;/* processor to which lwp is bound */
952 psetid_t pr_bindpset; /* processor set to which lwp is bound */
953 lgrp_id_t pr_lgrp /* home lgroup */
954 } lwpsinfo_t;
955 .fi
956 .in -2
957
958 .sp
959 .LP
960 Some of the entries in \fBlwpsinfo\fR, such as \fBpr_addr\fR, \fBpr_wchan\fR,
961 \fBpr_stype\fR, \fBpr_state\fR, and \fBpr_name\fR, refer to internal kernel
962 data structures and should not be expected to retain their meanings across
963 different versions of the operating system.
964 .sp
965 .LP
966 \fBlwpsinfo_t.pr_flag\fR is a deprecated interface that should no longer be
967 used.
968 .sp
969 .LP
970 \fBpr_pctcpu\fR is a 16-bit binary fraction, as described above. It represents
971 the \fBCPU\fR time used by the specific lwp. On a multi-processor machine, the
972 maximum value is 1/N, where N is the number of \fBCPU\fRs.
973 .sp
974 .LP
975 \fBpr_contract\fR is the id of the process contract of which the process is a
976 member. See \fBcontract\fR(4) and \fBprocess\fR(4).
977 .SS "cred"
978 .LP
979 Contains a description of the credentials associated with the process:
980 .sp
981 .in +2
982 .nf
983 typedef struct prcred {
984 uid_t pr_euid; /* effective user id */
985 uid_t pr_ruid; /* real user id */
986 uid_t pr_suid; /* saved user id (from exec) */
987 gid_t pr_egid; /* effective group id */
988 gid_t pr_rgid; /* real group id */
989 gid_t pr_sgid; /* saved group id (from exec) */
990 int pr_ngroups; /* number of supplementary groups */
991 gid_t pr_groups[1]; /* array of supplementary groups */
992 } prcred_t;
993 .fi
994 .in -2
995 .sp
996
997 .sp
998 .LP
999 The array of associated supplementary groups in \fBpr_groups\fR is of variable
1000 length; the \fBcred\fR file contains all of the supplementary groups.
1001 \fBpr_ngroups\fR indicates the number of supplementary groups. (See also the
1002 \fBPCSCRED\fR and \fBPCSCREDX\fR control operations.)
1003 .SS "priv"
1004 .LP
1005 Contains a description of the privileges associated with the process:
1006 .sp
1007 .in +2
1008 .nf
1009 typedef struct prpriv {
1010 uint32_t pr_nsets; /* number of privilege set */
1011 uint32_t pr_setsize; /* size of privilege set */
1012 uint32_t pr_infosize; /* size of supplementary data */
1013 priv_chunk_t pr_sets[1]; /* array of sets */
1014 } prpriv_t;
1015 .fi
1016 .in -2
1017
1018 .sp
1019 .LP
1020 The actual dimension of the \fBpr_sets\fR[] field is
1021 .sp
1022 .in +2
1023 .nf
1024 pr_sets[pr_nsets][pr_setsize]
1025 .fi
1026 .in -2
1027
1028 .sp
1029 .LP
1030 which is followed by additional information about the process state
1031 \fBpr_infosize\fR bytes in size.
1032 .sp
1033 .LP
1034 The full size of the structure can be computed using
1035 \fBPRIV_PRPRIV_SIZE\fR(\fBprpriv_t *\fR).
1036 .SS "secflags"
1037 .LP
1038 This file contains the security-flags of the process. It contains a
1039 description of the security flags associated with the process.
1040 .sp
1041 .in +2
1042 .nf
1043 typedef struct prsecflags {
1044 uint32_t pr_version; /* ABI Versioning of this structure */
1045 secflagset_t pr_effective; /* Effective flags */
1046 secflagset_t pr_inherit; /* Inheritable flags */
1047 secflagset_t pr_lower; /* Lower flags */
1048 secflagset_t pr_upper; /* Upper flags */
1049 } prsecflags_t;
1050 .in -2
1051
1052 .sp
1053 .LP
1054 The \fBpr_version\fR field is a version number for the structure, currently
1055 \fBPRSECFLAGS_VERSION_1\fR.
1056 .SS "sigact"
1057 .LP
1058 Contains an array of \fBsigaction structures\fR describing the current
1059 dispositions of all signals associated with the traced process (see
1060 \fBsigaction\fR(2)). Signal numbers are displaced by 1 from array indices, so
1061 that the action for signal number \fIn\fR appears in position \fIn\fR-1 of the
1062 array.
1063 .SS "auxv"
1064 .LP
1065 Contains the initial values of the process's aux vector in an array of
1066 \fBauxv_t\fR structures (see \fB<sys/auxv.h>\fR). The values are those that
1067 were passed by the operating system as startup information to the dynamic
1068 linker.
1069 .SS "ldt"
1070 .LP
1071 This file exists only on x86-based machines. It is non-empty only if the
1072 process has established a local descriptor table (\fBLDT\fR). If non-empty, the
1073 file contains the array of currently active \fBLDT\fR entries in an array of
1074 elements of type \fBstruct ssd\fR, defined in \fB<sys/sysi86.h>\fR, one element
1075 for each active \fBLDT\fR entry.
1076 .SS "map, xmap"
1077 .LP
1078 Contain information about the virtual address map of the process. The map file
1079 contains an array of \fBprmap\fR structures while the xmap file contains an
1080 array of \fBprxmap\fR structures. Each structure describes a contiguous virtual
1081 address region in the address space of the traced process:
1082 .sp
1083 .in +2
1084 .nf
1085 typedef struct prmap {
1086 uintptr_tpr_vaddr; /* virtual address of mapping */
1087 size_t pr_size; /* size of mapping in bytes */
1088 char pr_mapname[PRMAPSZ]; /* name in /proc/pid/object */
1089 offset_t pr_offset; /* offset into mapped object, if any */
1090 int pr_mflags; /* protection and attribute flags */
1091 int pr_pagesize; /* pagesize for this mapping in bytes */
1092 int pr_shmid; /* SysV shared memory identifier */
1093 } prmap_t;
1094 .fi
1095 .in -2
1096 .sp
1097
1098 .sp
1099 .in +2
1100 .nf
1101 typedef struct prxmap {
1102 uintptr_t pr_vaddr; /* virtual address of mapping */
1103 size_t pr_size; /* size of mapping in bytes */
1104 char pr_mapname[PRMAPSZ]; /* name in /proc/pid/object */
1105 offset_t pr_offset; /* offset into mapped object, if any */
1106 int pr_mflags; /* protection and attribute flags */
1107 int pr_pagesize; /* pagesize for this mapping in bytes */
1108 int pr_shmid; /* SysV shared memory identifier */
1109 dev_t pr_dev; /* device of mapped object, if any */
1110 uint64_t pr_ino; /* inode of mapped object, if any */
1111 size_t pr_rss; /* pages of resident memory */
1112 size_t pr_anon; /* pages of resident anonymous memory */
1113 size_t pr_locked; /* pages of locked memory */
1114 uint64_t pr_hatpagesize; /* pagesize of mapping */
1115 } prxmap_t;
1116 .fi
1117 .in -2
1118 .sp
1119
1120 .sp
1121 .LP
1122 \fBpr_vaddr\fR is the virtual address of the mapping within the traced process
1123 and \fBpr_size\fR is its size in bytes. \fBpr_mapname\fR, if it does not
1124 contain a null string, contains the name of a file in the \fBobject\fR
1125 directory (see below) that can be opened read-only to obtain a file descriptor
1126 for the mapped file associated with the mapping. This enables a debugger to
1127 find object file symbol tables without having to know the real path names of
1128 the executable file and shared libraries of the process. \fBpr_offset\fR is the
1129 64-bit offset within the mapped file (if any) to which the virtual address is
1130 mapped.
1131 .sp
1132 .LP
1133 \fBpr_mflags\fR is a bit-mask of protection and attribute flags:
1134 .sp
1135 .ne 2
1136 .na
1137 \fB\fBMA_READ\fR\fR
1138 .ad
1139 .RS 17n
1140 mapping is readable by the traced process.
1141 .RE
1142
1143 .sp
1144 .ne 2
1145 .na
1146 \fB\fBMA_WRITE\fR\fR
1147 .ad
1148 .RS 17n
1149 mapping is writable by the traced process.
1150 .RE
1151
1152 .sp
1153 .ne 2
1154 .na
1155 \fB\fBMA_EXEC\fR\fR
1156 .ad
1157 .RS 17n
1158 mapping is executable by the traced process.
1159 .RE
1160
1161 .sp
1162 .ne 2
1163 .na
1164 \fB\fBMA_SHARED\fR\fR
1165 .ad
1166 .RS 17n
1167 mapping changes are shared by the mapped object.
1168 .RE
1169
1170 .sp
1171 .ne 2
1172 .na
1173 \fB\fBMA_ISM\fR\fR
1174 .ad
1175 .RS 17n
1176 mapping is intimate shared memory (shared MMU resources)
1177 .RE
1178
1179 .sp
1180 .ne 2
1181 .na
1182 \fB\fBMAP_NORESERVE\fR\fR
1183 .ad
1184 .RS 17n
1185 mapping does not have swap space reserved (mapped with MAP_NORESERVE)
1186 .RE
1187
1188 .sp
1189 .ne 2
1190 .na
1191 \fB\fBMA_SHM\fR\fR
1192 .ad
1193 .RS 17n
1194 mapping System V shared memory
1195 .RE
1196
1197 .sp
1198 .LP
1199 A contiguous area of the address space having the same underlying mapped object
1200 may appear as multiple mappings due to varying read, write, and execute
1201 attributes. The underlying mapped object does not change over the range of a
1202 single mapping. An \fBI/O\fR operation to a mapping marked \fBMA_SHARED\fR
1203 fails if applied at a virtual address not corresponding to a valid page in the
1204 underlying mapped object. A write to a \fBMA_SHARED\fR mapping that is not
1205 marked \fBMA_WRITE\fR fails. Reads and writes to private mappings always
1206 succeed. Reads and writes to unmapped addresses fail.
1207 .sp
1208 .LP
1209 \fBpr_pagesize\fR is the page size for the mapping, currently always the system
1210 pagesize.
1211 .sp
1212 .LP
1213 \fBpr_shmid\fR is the shared memory identifier, if any, for the mapping. Its
1214 value is \fB\(mi1\fR if the mapping is not System V shared memory. See
1215 \fBshmget\fR(2).
1216 .sp
1217 .LP
1218 \fBpr_dev\fR is the device of the mapped object, if any, for the mapping. Its
1219 value is \fBPRNODEV\fR (-1) if the mapping does not have a device.
1220 .sp
1221 .LP
1222 \fBpr_ino\fR is the inode of the mapped object, if any, for the mapping. Its
1223 contents are only valid if \fBpr_dev\fR is not \fBPRNODEV.\fR
1224 .sp
1225 .LP
1226 \fBpr_rss\fR is the number of resident pages of memory for the mapping. The
1227 number of resident bytes for the mapping may be determined by multiplying
1228 \fBpr_rss\fR by the page size given by \fBpr_pagesize.\fR
1229 .sp
1230 .LP
1231 \fBpr_anon\fR is the number of resident anonymous memory pages (pages which are
1232 private to this process) for the mapping.
1233 .sp
1234 .LP
1235 \fBpr_locked\fR is the number of locked pages for the mapping. Pages which are
1236 locked are always resident in memory.
1237 .sp
1238 .LP
1239 \fBpr_hatpagesize\fR is the size, in bytes, of the \fBHAT\fR (\fBMMU\fR)
1240 translation for the mapping. \fBpr_hatpagesize\fR may be different than
1241 \fBpr_pagesize.\fR The possible values are hardware architecture specific, and
1242 may change over a mapping's lifetime.
1243 .SS "rmap"
1244 .LP
1245 Contains information about the reserved address ranges of the process. The file
1246 contains an array of \fBprmap\fR structures, as defined above for the \fBmap\fR
1247 file. Each structure describes a contiguous virtual address region in the
1248 address space of the traced process that is reserved by the system in the sense
1249 that an \fBmmap\fR(2) system call that does not specify \fBMAP_FIXED\fR will
1250 not use any part of it for the new mapping. Examples of such reservations
1251 include the address ranges reserved for the process stack and the individual
1252 thread stacks of a multi-threaded process.
1253 .SS "cwd"
1254 .LP
1255 A symbolic link to the process's current working directory. See \fBchdir\fR(2).
1256 A \fBreadlink\fR(2) of \fB/proc/\fIpid\fR/cwd\fR yields a null string. However,
1257 it can be opened, listed, and searched as a directory, and can be the target of
1258 \fBchdir\fR(2).
1259 .SS "root"
1260 .LP
1261 A symbolic link to the process's root directory.
1262 \fB/proc/\fR\fIpid\fR\fB/root\fR can differ from the system root directory if
1263 the process or one of its ancestors executed \fBchroot\fR(2) as super user. It
1264 has the same semantics as \fB/proc/\fR\fIpid\fR\fB/cwd\fR.
1265 .SS "fd"
1266 .LP
1267 A directory containing references to the open files of the process. Each entry
1268 is a decimal number corresponding to an open file descriptor in the process.
1269 .sp
1270 .LP
1271 If an entry refers to a regular file, it can be opened with normal file system
1272 semantics but, to ensure that the controlling process cannot gain greater
1273 access than the controlled process, with no file access modes other than its
1274 read/write open modes in the controlled process. If an entry refers to a
1275 directory, it can be accessed with the same semantics as
1276 \fB/proc/\fIpid\fR/cwd\fR. An attempt to open any other type of entry fails
1277 with \fBEACCES\fR.
1278 .SS "object"
1279 .LP
1280 A directory containing read-only files with names corresponding to the
1281 \fBpr_mapname\fR entries in the \fBmap\fR and \fBpagedata\fR files. Opening
1282 such a file yields a file descriptor for the underlying mapped file associated
1283 with an address-space mapping in the process. The file name \fBa.out\fR appears
1284 in the directory as an alias for the process's executable file.
1285 .sp
1286 .LP
1287 The \fBobject\fR directory makes it possible for a controlling process to gain
1288 access to the object file and any shared libraries (and consequently the symbol
1289 tables) without having to know the actual path names of the executable files.
1290 .SS "path"
1291 .LP
1292 A directory containing symbolic links to files opened by the process. The
1293 directory includes one entry for \fBcwd\fR and \fBroot\fR. The directory also
1294 contains a numerical entry for each file descriptor in the \fBfd\fR directory,
1295 and entries matching those in the \fBobject\fR directory. If this information
1296 is not available, any attempt to read the contents of the symbolic link will
1297 fail. This is most common for files that do not exist in the filesystem
1298 namespace (such as \fBFIFO\fRs and sockets), but can also happen for regular
1299 files. For the file descriptor entries, the path may be different from the one
1300 used by the process to open the file.
1301 .SS "pagedata"
1302 .LP
1303 Opening the page data file enables tracking of address space references and
1304 modifications on a per-page basis.
1305 .sp
1306 .LP
1307 A \fBread\fR(2) of the page data file descriptor returns structured page data
1308 and atomically clears the page data maintained for the file by the system. That
1309 is to say, each read returns data collected since the last read; the first read
1310 returns data collected since the file was opened. When the call completes, the
1311 read buffer contains the following structure as its header and thereafter
1312 contains a number of section header structures and associated byte arrays that
1313 must be accessed by walking linearly through the buffer.
1314 .sp
1315 .in +2
1316 .nf
1317 typedef struct prpageheader {
1318 timestruc_t pr_tstamp; /* real time stamp, time of read() */
1319 ulong_t pr_nmap; /* number of address space mappings */
1320 ulong_t pr_npage; /* total number of pages */
1321 } prpageheader_t;
1322 .fi
1323 .in -2
1324
1325 .sp
1326 .LP
1327 The header is followed by \fBpr_nmap prasmap\fR structures and associated data
1328 arrays. The \fBprasmap\fR structure contains the following elements:
1329 .sp
1330 .in +2
1331 .nf
1332 typedef struct prasmap {
1333 uintptr_t pr_vaddr; /* virtual address of mapping */
1334 ulong_t pr_npage; /* number of pages in mapping */
1335 char pr_mapname[PRMAPSZ]; /* name in /proc/pid/object */
1336 offset_t pr_offset; /* offset into mapped object, if any */
1337 int pr_mflags; /* protection and attribute flags */
1338 int pr_pagesize; /* pagesize for this mapping in bytes */
1339 int pr_shmid; /* SysV shared memory identifier */
1340 } prasmap_t;
1341 .fi
1342 .in -2
1343
1344 .sp
1345 .LP
1346 Each section header is followed by \fBpr_npage\fR bytes, one byte for each page
1347 in the mapping, plus 0-7 null bytes at the end so that the next \fBprasmap\fR
1348 structure begins on an eight-byte aligned boundary. Each data byte may contain
1349 these flags:
1350 .sp
1351 .ne 2
1352 .na
1353 \fB\fBPG_REFERENCED\fR\fR
1354 .ad
1355 .RS 17n
1356 page has been referenced.
1357 .RE
1358
1359 .sp
1360 .ne 2
1361 .na
1362 \fB\fBPG_MODIFIED\fR\fR
1363 .ad
1364 .RS 17n
1365 page has been modified.
1366 .RE
1367
1368 .sp
1369 .LP
1370 If the read buffer is not large enough to contain all of the page data, the
1371 read fails with \fBE2BIG\fR and the page data is not cleared. The required size
1372 of the read buffer can be determined through \fBfstat\fR(2). Application of
1373 \fBlseek\fR(2) to the page data file descriptor is ineffective; every read
1374 starts from the beginning of the file. Closing the page data file descriptor
1375 terminates the system overhead associated with collecting the data.
1376 .sp
1377 .LP
1378 More than one page data file descriptor for the same process can be opened, up
1379 to a system-imposed limit per traced process. A read of one does not affect the
1380 data being collected by the system for the others. An open of the page data
1381 file will fail with \fBENOMEM\fR if the system-imposed limit would be exceeded.
1382 .SS "watch"
1383 .LP
1384 Contains an array of \fBprwatch\fR structures, one for each watched area
1385 established by the \fBPCWATCH\fR control operation. See \fBPCWATCH\fR for
1386 details.
1387 .SS "usage"
1388 .LP
1389 Contains process usage information described by a \fBprusage\fR structure which
1390 contains at least the following fields:
1391 .sp
1392 .in +2
1393 .nf
1394 typedef struct prusage {
1395 id_t pr_lwpid; /* lwp id. 0: process or defunct */
1396 int pr_count; /* number of contributing lwps */
1397 timestruc_t pr_tstamp; /* real time stamp, time of read() */
1398 timestruc_t pr_create; /* process/lwp creation time stamp */
1399 timestruc_t pr_term; /* process/lwp termination time stamp */
1400 timestruc_t pr_rtime; /* total lwp real (elapsed) time */
1401 timestruc_t pr_utime; /* user level CPU time */
1402 timestruc_t pr_stime; /* system call CPU time */
1403 timestruc_t pr_ttime; /* other system trap CPU time */
1404 timestruc_t pr_tftime; /* text page fault sleep time */
1405 timestruc_t pr_dftime; /* data page fault sleep time */
1406 timestruc_t pr_kftime; /* kernel page fault sleep time */
1407 timestruc_t pr_ltime; /* user lock wait sleep time */
1408 timestruc_t pr_slptime; /* all other sleep time */
1409 timestruc_t pr_wtime; /* wait-cpu (latency) time */
1410 timestruc_t pr_stoptime; /* stopped time */
1411 ulong_t pr_minf; /* minor page faults */
1412 ulong_t pr_majf; /* major page faults */
1413 ulong_t pr_nswap; /* swaps */
1414 ulong_t pr_inblk; /* input blocks */
1415 ulong_t pr_oublk; /* output blocks */
1416 ulong_t pr_msnd; /* messages sent */
1417 ulong_t pr_mrcv; /* messages received */
1418 ulong_t pr_sigs; /* signals received */
1419 ulong_t pr_vctx; /* voluntary context switches */
1420 ulong_t pr_ictx; /* involuntary context switches */
1421 ulong_t pr_sysc; /* system calls */
1422 ulong_t pr_ioch; /* chars read and written */
1423 } prusage_t;
1424 .fi
1425 .in -2
1426
1427 .sp
1428 .LP
1429 Microstate accounting is now continuously enabled. While this information was
1430 previously an estimate, if microstate accounting were not enabled, the current
1431 information is now never an estimate represents time the process has spent in
1432 various states.
1433 .SS "lstatus"
1434 .LP
1435 Contains a \fBprheader\fR structure followed by an array of \fBlwpstatus\fR
1436 structures, one for each active lwp in the process (see also
1437 \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwpid\fR/\fBlwpstatus\fR, below). The
1438 \fBprheader\fR structure describes the number and size of the array entries
1439 that follow.
1440 .sp
1441 .in +2
1442 .nf
1443 typedef struct prheader {
1444 long pr_nent; /* number of entries */
1445 size_t pr_entsize; /* size of each entry, in bytes */
1446 } prheader_t;
1447 .fi
1448 .in -2
1449
1450 .sp
1451 .LP
1452 The \fBlwpstatus\fR structure may grow by the addition of elements at the end
1453 in future releases of the system. Programs must use \fBpr_entsize\fR in the
1454 file header to index through the array. These comments apply to all \fB/proc\fR
1455 files that include a \fBprheader\fR structure (\fBlpsinfo\fR and \fBlusage\fR,
1456 below).
1457 .SS "lpsinfo"
1458 .LP
1459 Contains a \fBprheader\fR structure followed by an array of \fBlwpsinfo\fR
1460 structures, one for eachactive and zombie lwp in the process. See also
1461 \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwpid\fR/\fBlwpsinfo\fR, below.
1462 .SS "lusage"
1463 .LP
1464 Contains a \fBprheader\fR structure followed by an array of \fBprusage\fR
1465 structures, one for each active lwp in the process, plus an additional element
1466 at the beginning that contains the summation over all defunct lwps (lwps that
1467 once existed but no longer exist in the process). Excluding the \fBpr_lwpid\fR,
1468 \fBpr_tstamp\fR, \fBpr_create\fR, and \fBpr_term\fR entries, the entry-by-entry
1469 summation over all these structures is the definition of the process usage
1470 information obtained from the \fBusage\fR file. (See also
1471 \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwpid\fR/\fBlwpusage\fR, below.)
1472 .SS "lwp"
1473 .LP
1474 A directory containing entries each of which names an active or zombie lwp
1475 within the process. These entries are themselves directories containing
1476 additional files as described below. Only the \fBlwpsinfo\fR file exists in the
1477 directory of a zombie lwp.
1478 .SH STRUCTURE OF \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwpid\fR
1479 .LP
1480 A given directory \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwpid\fR contains the
1481 following entries:
1482 .SS "lwpctl"
1483 .LP
1484 Write-only control file. The messages written to this file affect the specific
1485 lwp rather than the representative lwp, as is the case for the process's
1486 \fBctl\fR file.
1487 .SS "lwpstatus"
1488 .LP
1489 lwp-specific state information. This file contains the \fBlwpstatus\fR
1490 structure for the specific lwp as described above for the representative lwp in
1491 the process's \fBstatus\fR file.
1492 .SS "lwpsinfo"
1493 .LP
1494 lwp-specific \fBps\fR(1) information. This file contains the \fBlwpsinfo\fR
1495 structure for the specific lwp as described above for the representative lwp in
1496 the process's \fBpsinfo\fR file. The \fBlwpsinfo\fR file remains accessible
1497 after an lwp becomes a zombie.
1498 .SS "lwpusage"
1499 .LP
1500 This file contains the \fBprusage\fR structure for the specific lwp as
1501 described above for the process's \fBusage\fR file.
1502 .SS "gwindows"
1503 .LP
1504 This file exists only on SPARC based machines. If it is non-empty, it contains
1505 a \fBgwindows_t\fR structure, defined in \fB<sys/regset.h>\fR, with the values
1506 of those SPARC register windows that could not be stored on the stack when the
1507 lwp stopped. Conditions under which register windows are not stored on the
1508 stack are: the stack pointer refers to nonexistent process memory or the stack
1509 pointer is improperly aligned. If the lwp is not stopped or if there are no
1510 register windows that could not be stored on the stack, the file is empty (the
1511 usual case).
1512 .SS "xregs"
1513 .LP
1514 Extra state registers. The extra state register set is architecture dependent;
1515 this file is empty if the system does not support extra state registers. If the
1516 file is non-empty, it contains an architecture dependent structure of type
1517 \fBprxregset_t\fR, defined in \fB<procfs.h>\fR, with the values of the lwp's
1518 extra state registers. If the lwp is not stopped, all register values are
1519 undefined. See also the \fBPCSXREG\fR control operation, below.
1520 .SS "asrs"
1521 .LP
1522 This file exists only for 64-bit SPARC V9 processes. It contains an
1523 \fBasrset_t\fR structure, defined in <\fBsys/regset.h\fR>, containing the
1524 values of the lwp's platform-dependent ancillary state registers. If the lwp is
1525 not stopped, all register values are undefined. See also the \fBPCSASRS\fR
1526 control operation, below.
1527 .SS "spymaster"
1528 .LP
1529 For an agent lwp (see \fBPCAGENT\fR), this file contains a \fBpsinfo_t\fR
1530 structure that corresponds to the process that created the agent lwp at the
1531 time the agent was created. This structure is identical to that retrieved via
1532 the \fBpsinfo\fR file, with one modification: the \fBpr_time\fR field does not
1533 correspond to the CPU time for the process, but rather to the creation time of
1534 the agent lwp.
1535 .SS "templates"
1536 .LP
1537 A directory which contains references to the active templates for the lwp,
1538 named by the contract type. Changes made to an active template descriptor do
1539 not affect the original template which was activated, though they do affect the
1540 active template. It is not possible to activate an active template descriptor.
1541 See \fBcontract\fR(4).
1542 .SH CONTROL MESSAGES
1543 .LP
1544 Process state changes are effected through messages written to a process's
1545 \fBctl\fR file or to an individual lwp's \fBlwpctl\fR file. All control
1546 messages consist of a \fBlong\fR that names the specific operation followed by
1547 additional data containing the operand, if any.
1548 .sp
1549 .LP
1550 Multiple control messages may be combined in a single \fBwrite\fR(2) (or
1551 \fBwritev\fR(2)) to a control file, but no partial writes are permitted. That
1552 is, each control message, operation code plus operand, if any, must be
1553 presented in its entirety to the \fBwrite\fR(2) and not in pieces over several
1554 system calls. If a control operation fails, no subsequent operations contained
1555 in the same \fBwrite\fR(2) are attempted.
1556 .sp
1557 .LP
1558 Descriptions of the allowable control messages follow. In all cases, writing a
1559 message to a control file for a process or lwp that has terminated elicits the
1560 error \fBENOENT\fR.
1561 .SS "PCSTOP PCDSTOP PCWSTOP PCTWSTOP"
1562 .LP
1563 When applied to the process control file, \fBPCSTOP\fR directs all lwps to stop
1564 and waits for them to stop, \fBPCDSTOP\fR directs all lwps to stop without
1565 waiting for them to stop, and \fBPCWSTOP\fR simply waits for all lwps to stop.
1566 When applied to an lwp control file, \fBPCSTOP\fR directs the specific lwp to
1567 stop and waits until it has stopped, \fBPCDSTOP\fR directs the specific lwp to
1568 stop without waiting for it to stop, and \fBPCWSTOP\fR simply waits for the
1569 specific lwp to stop. When applied to an lwp control file, \fBPCSTOP\fR and
1570 \fBPCWSTOP\fR complete when the lwp stops on an event of interest, immediately
1571 if already so stopped; when applied to the process control file, they complete
1572 when every lwp has stopped either on an event of interest or on a
1573 \fBPR_SUSPENDED\fR stop.
1574 .sp
1575 .LP
1576 \fBPCTWSTOP\fR is identical to \fBPCWSTOP\fR except that it enables the
1577 operation to time out, to avoid waiting forever for a process or lwp that may
1578 never stop on an event of interest. \fBPCTWSTOP\fR takes a \fBlong\fR operand
1579 specifying a number of milliseconds; the wait will terminate successfully after
1580 the specified number of milliseconds even if the process or lwp has not
1581 stopped; a timeout value of zero makes the operation identical to
1582 \fBPCWSTOP\fR.
1583 .sp
1584 .LP
1585 An ``event of interest'' is either a \fBPR_REQUESTED\fR stop or a stop that has
1586 been specified in the process's tracing flags (set by \fBPCSTRACE\fR,
1587 \fBPCSFAULT\fR, \fBPCSENTRY\fR, and \fBPCSEXIT\fR). \fBPR_JOBCONTROL\fR and
1588 \fBPR_SUSPENDED\fR stops are specifically not events of interest. (An lwp may
1589 stop twice due to a stop signal, first showing \fBPR_SIGNALLED\fR if the signal
1590 is traced and again showing \fBPR_JOBCONTROL\fR if the lwp is set running
1591 without clearing the signal.) If \fBPCSTOP\fR or \fBPCDSTOP\fR is applied to an
1592 lwp that is stopped, but not on an event of interest, the stop directive takes
1593 effect when the lwp is restarted by the competing mechanism. At that time, the
1594 lwp enters a \fBPR_REQUESTED\fR stop before executing any user-level code.
1595 .sp
1596 .LP
1597 A write of a control message that blocks is interruptible by a signal so that,
1598 for example, an \fBalarm\fR(2) can be set to avoid waiting forever for a
1599 process or lwp that may never stop on an event of interest. If \fBPCSTOP\fR is
1600 interrupted, the lwp stop directives remain in effect even though the
1601 \fBwrite\fR(2) returns an error. (Use of \fBPCTWSTOP\fR with a non-zero timeout
1602 is recommended over \fBPCWSTOP\fR with an \fBalarm\fR(2).)
1603 .sp
1604 .LP
1605 A system process (indicated by the \fBPR_ISSYS\fR flag) never executes at user
1606 level, has no user-level address space visible through \fB/proc\fR, and cannot
1607 be stopped. Applying one of these operations to a system process or any of its
1608 lwps elicits the error \fBEBUSY\fR.
1609 .SS "PCRUN"
1610 .LP
1611 Make an lwp runnable again after a stop. This operation takes a \fBlong\fR
1612 operand containing zero or more of the following flags:
1613 .sp
1614 .ne 2
1615 .na
1616 \fB\fBPRCSIG\fR\fR
1617 .ad
1618 .RS 12n
1619 clears the current signal, if any (see \fBPCCSIG\fR).
1620 .RE
1621
1622 .sp
1623 .ne 2
1624 .na
1625 \fB\fBPRCFAULT\fR\fR
1626 .ad
1627 .RS 12n
1628 clears the current fault, if any (see \fBPCCFAULT\fR).
1629 .RE
1630
1631 .sp
1632 .ne 2
1633 .na
1634 \fB\fBPRSTEP\fR\fR
1635 .ad
1636 .RS 12n
1637 directs the lwp to execute a single machine instruction. On completion of the
1638 instruction, a trace trap occurs. If \fBFLTTRACE\fR is being traced, the lwp
1639 stops; otherwise, it is sent \fBSIGTRAP\fR. If \fBSIGTRAP\fR is being traced
1640 and is not blocked, the lwp stops. When the lwp stops on an event of interest,
1641 the single-step directive is cancelled, even if the stop occurs before the
1642 instruction is executed. This operation requires hardware and operating system
1643 support and may not be implemented on all processors. It is implemented on
1644 SPARC and x86-based machines.
1645 .RE
1646
1647 .sp
1648 .ne 2
1649 .na
1650 \fB\fBPRSABORT\fR\fR
1651 .ad
1652 .RS 12n
1653 is meaningful only if the lwp is in a \fBPR_SYSENTRY\fR stop or is marked
1654 \fBPR_ASLEEP\fR; it instructs the lwp to abort execution of the system call
1655 (see \fBPCSENTRY\fR and \fBPCSEXIT\fR).
1656 .RE
1657
1658 .sp
1659 .ne 2
1660 .na
1661 \fB\fBPRSTOP\fR\fR
1662 .ad
1663 .RS 12n
1664 directs the lwp to stop again as soon as possible after resuming execution (see
1665 \fBPCDSTOP\fR). In particular, if the lwp is stopped on \fBPR_SIGNALLED\fR or
1666 \fBPR_FAULTED\fR, the next stop will show \fBPR_REQUESTED\fR, no other stop
1667 will have intervened, and the lwp will not have executed any user-level code.
1668 .RE
1669
1670 .sp
1671 .LP
1672 When applied to an lwp control file, \fBPCRUN\fR clears any outstanding
1673 directed-stop request and makes the specific lwp runnable. The operation fails
1674 with \fBEBUSY\fR if the specific lwp is not stopped on an event of interest or
1675 has not been directed to stop or if the agent lwp exists and this is not the
1676 agent lwp (see \fBPCAGENT\fR).
1677 .sp
1678 .LP
1679 When applied to the process control file, a representative lwp is chosen for
1680 the operation as described for \fB/proc/\fR\fIpid\fR\fB/status\fR. The
1681 operation fails with \fBEBUSY\fR if the representative lwp is not stopped on an
1682 event of interest or has not been directed to stop or if the agent lwp exists.
1683 If \fBPRSTEP\fR or \fBPRSTOP\fR was requested, the representative lwp is made
1684 runnable and its outstanding directed-stop request is cleared; otherwise all
1685 outstanding directed-stop requests are cleared and, if it was stopped on an
1686 event of interest, the representative lwp is marked \fBPR_REQUESTED\fR. If, as
1687 a consequence, all lwps are in the \fBPR_REQUESTED\fR or \fBPR_SUSPENDED\fR
1688 stop state, all lwps showing \fBPR_REQUESTED\fR are made runnable.
1689 .SS "PCSTRACE"
1690 .LP
1691 Define a set of signals to be traced in the process. The receipt of one of
1692 these signals by an lwp causes the lwp to stop. The set of signals is defined
1693 using an operand \fBsigset_t\fR contained in the control message. Receipt of
1694 \fBSIGKILL\fR cannot be traced; if specified, it is silently ignored.
1695 .sp
1696 .LP
1697 If a signal that is included in an lwp's held signal set (the signal mask) is
1698 sent to the lwp, the signal is not received and does not cause a stop until it
1699 is removed from the held signal set, either by the lwp itself or by setting the
1700 held signal set with \fBPCSHOLD\fR.
1701 .SS "PCCSIG"
1702 .LP
1703 The current signal, if any, is cleared from the specific or representative lwp.
1704 .SS "PCSSIG"
1705 .LP
1706 The current signal and its associated signal information for the specific or
1707 representative lwp are set according to the contents of the operand
1708 \fBsiginfo\fR structure (see \fB<sys/siginfo.h>\fR). If the specified signal
1709 number is zero, the current signal is cleared. The semantics of this operation
1710 are different from those of \fBkill\fR(2) in that the signal is delivered to
1711 the lwp immediately after execution is resumed (even if it is being blocked)
1712 and an additional \fBPR_SIGNALLED\fR stop does not intervene even if the signal
1713 is traced. Setting the current signal to \fBSIGKILL\fR terminates the process
1714 immediately.
1715 .SS "PCKILL"
1716 .LP
1717 If applied to the process control file, a signal is sent to the process with
1718 semantics identical to those of \fBkill\fR(2). If applied to an lwp control
1719 file, a directed signal is sent to the specific lwp. The signal is named in a
1720 \fBlong\fR operand contained in the message. Sending \fBSIGKILL\fR terminates
1721 the process immediately.
1722 .SS "PCUNKILL"
1723 .LP
1724 A signal is deleted, that is, it is removed from the set of pending signals. If
1725 applied to the process control file, the signal is deleted from the process's
1726 pending signals. If applied to an lwp control file, the signal is deleted from
1727 the lwp's pending signals. The current signal (if any) is unaffected. The
1728 signal is named in a \fBlong\fR operand in the control message. It is an error
1729 (\fBEINVAL\fR) to attempt to delete \fBSIGKILL\fR.
1730 .SS "PCSHOLD"
1731 .LP
1732 Set the set of held signals for the specific or representative lwp (signals
1733 whose delivery will be blocked if sent to the lwp). The set of signals is
1734 specified with a \fBsigset_t\fR operand. \fBSIGKILL\fR and \fBSIGSTOP\fR cannot
1735 be held; if specified, they are silently ignored.
1736 .SS "PCSFAULT"
1737 .LP
1738 Define a set of hardware faults to be traced in the process. On incurring one
1739 of these faults, an lwp stops. The set is defined via the operand
1740 \fBfltset_t\fR structure. Fault names are defined in \fB<sys/fault.h>\fR and
1741 include the following. Some of these may not occur on all processors; there may
1742 be processor-specific faults in addition to these.
1743 .sp
1744 .ne 2
1745 .na
1746 \fB\fBFLTILL\fR\fR
1747 .ad
1748 .RS 13n
1749 illegal instruction
1750 .RE
1751
1752 .sp
1753 .ne 2
1754 .na
1755 \fB\fBFLTPRIV\fR\fR
1756 .ad
1757 .RS 13n
1758 privileged instruction
1759 .RE
1760
1761 .sp
1762 .ne 2
1763 .na
1764 \fB\fBFLTBPT\fR\fR
1765 .ad
1766 .RS 13n
1767 breakpoint trap
1768 .RE
1769
1770 .sp
1771 .ne 2
1772 .na
1773 \fB\fBFLTTRACE\fR\fR
1774 .ad
1775 .RS 13n
1776 trace trap (single-step)
1777 .RE
1778
1779 .sp
1780 .ne 2
1781 .na
1782 \fB\fBFLTWATCH\fR\fR
1783 .ad
1784 .RS 13n
1785 watchpoint trap
1786 .RE
1787
1788 .sp
1789 .ne 2
1790 .na
1791 \fB\fBFLTACCESS\fR\fR
1792 .ad
1793 .RS 13n
1794 memory access fault (bus error)
1795 .RE
1796
1797 .sp
1798 .ne 2
1799 .na
1800 \fB\fBFLTBOUNDS\fR\fR
1801 .ad
1802 .RS 13n
1803 memory bounds violation
1804 .RE
1805
1806 .sp
1807 .ne 2
1808 .na
1809 \fB\fBFLTIOVF\fR\fR
1810 .ad
1811 .RS 13n
1812 integer overflow
1813 .RE
1814
1815 .sp
1816 .ne 2
1817 .na
1818 \fB\fBFLTIZDIV\fR\fR
1819 .ad
1820 .RS 13n
1821 integer zero divide
1822 .RE
1823
1824 .sp
1825 .ne 2
1826 .na
1827 \fB\fBFLTFPE\fR\fR
1828 .ad
1829 .RS 13n
1830 floating-point exception
1831 .RE
1832
1833 .sp
1834 .ne 2
1835 .na
1836 \fB\fBFLTSTACK\fR\fR
1837 .ad
1838 .RS 13n
1839 unrecoverable stack fault
1840 .RE
1841
1842 .sp
1843 .ne 2
1844 .na
1845 \fB\fBFLTPAGE\fR\fR
1846 .ad
1847 .RS 13n
1848 recoverable page fault
1849 .RE
1850
1851 .sp
1852 .LP
1853 When not traced, a fault normally results in the posting of a signal to the lwp
1854 that incurred the fault. If an lwp stops on a fault, the signal is posted to
1855 the lwp when execution is resumed unless the fault is cleared by \fBPCCFAULT\fR
1856 or by the \fBPRCFAULT\fR option of \fBPCRUN\fR. \fBFLTPAGE\fR is an exception;
1857 no signal is posted. The \fBpr_info\fR field in the \fBlwpstatus\fR structure
1858 identifies the signal to be sent and contains machine-specific information
1859 about the fault.
1860 .SS "PCCFAULT"
1861 .LP
1862 The current fault, if any, is cleared; the associated signal will not be sent
1863 to the specific or representative lwp.
1864 .SS "PCSENTRY PCSEXIT"
1865 .LP
1866 These control operations instruct the process's lwps to stop on entry to or
1867 exit from specified system calls. The set of system calls to be traced is
1868 defined via an operand \fBsysset_t\fR structure.
1869 .sp
1870 .LP
1871 When entry to a system call is being traced, an lwp stops after having begun
1872 the call to the system but before the system call arguments have been fetched
1873 from the lwp. When exit from a system call is being traced, an lwp stops on
1874 completion of the system call just prior to checking for signals and returning
1875 to user level. At this point, all return values have been stored into the lwp's
1876 registers.
1877 .sp
1878 .LP
1879 If an lwp is stopped on entry to a system call (\fBPR_SYSENTRY\fR) or when
1880 sleeping in an interruptible system call (\fBPR_ASLEEP\fR is set), it may be
1881 instructed to go directly to system call exit by specifying the \fBPRSABORT\fR
1882 flag in a \fBPCRUN\fR control message. Unless exit from the system call is
1883 being traced, the lwp returns to user level showing \fBEINTR\fR.
1884 .SS "PCWATCH"
1885 .LP
1886 Set or clear a watched area in the controlled process from a \fBprwatch\fR
1887 structure operand:
1888 .sp
1889 .in +2
1890 .nf
1891 typedef struct prwatch {
1892 uintptr_t pr_vaddr; /* virtual address of watched area */
1893 size_t pr_size; /* size of watched area in bytes */
1894 int pr_wflags; /* watch type flags */
1895 } prwatch_t;
1896 .fi
1897 .in -2
1898
1899 .sp
1900 .LP
1901 \fBpr_vaddr\fR specifies the virtual address of an area of memory to be watched
1902 in the controlled process. \fBpr_size\fR specifies the size of the area, in
1903 bytes. \fBpr_wflags\fR specifies the type of memory access to be monitored as a
1904 bit-mask of the following flags:
1905 .sp
1906 .ne 2
1907 .na
1908 \fB\fBWA_READ\fR\fR
1909 .ad
1910 .RS 16n
1911 read access
1912 .RE
1913
1914 .sp
1915 .ne 2
1916 .na
1917 \fB\fBWA_WRITE\fR\fR
1918 .ad
1919 .RS 16n
1920 write access
1921 .RE
1922
1923 .sp
1924 .ne 2
1925 .na
1926 \fB\fBWA_EXEC\fR\fR
1927 .ad
1928 .RS 16n
1929 execution access
1930 .RE
1931
1932 .sp
1933 .ne 2
1934 .na
1935 \fB\fBWA_TRAPAFTER\fR\fR
1936 .ad
1937 .RS 16n
1938 trap after the instruction completes
1939 .RE
1940
1941 .sp
1942 .LP
1943 If \fBpr_wflags\fR is non-empty, a watched area is established for the virtual
1944 address range specified by \fBpr_vaddr\fR and \fBpr_size\fR. If \fBpr_wflags\fR
1945 is empty, any previously-established watched area starting at the specified
1946 virtual address is cleared; \fBpr_size\fR is ignored.
1947 .sp
1948 .LP
1949 A watchpoint is triggered when an lwp in the traced process makes a memory
1950 reference that covers at least one byte of a watched area and the memory
1951 reference is as specified in \fBpr_wflags\fR. When an lwp triggers a
1952 watchpoint, it incurs a watchpoint trap. If \fBFLTWATCH\fR is being traced, the
1953 lwp stops; otherwise, it is sent a \fBSIGTRAP\fR signal; if \fBSIGTRAP\fR is
1954 being traced and is not blocked, the lwp stops.
1955 .sp
1956 .LP
1957 The watchpoint trap occurs before the instruction completes unless
1958 \fBWA_TRAPAFTER\fR was specified, in which case it occurs after the instruction
1959 completes. If it occurs before completion, the memory is not modified. If it
1960 occurs after completion, the memory is modified (if the access is a write
1961 access).
1962 .sp
1963 .LP
1964 Physical i/o is an exception for watchpoint traps. In this instance, there is
1965 no guarantee that memory before the watched area has already been modified (or
1966 in the case of \fBWA_TRAPAFTER\fR, that the memory following the watched area
1967 has not been modified) when the watchpoint trap occurs and the lwp stops.
1968 .sp
1969 .LP
1970 \fBpr_info\fR in the \fBlwpstatus\fR structure contains information pertinent
1971 to the watchpoint trap. In particular, the \fBsi_addr\fR field contains the
1972 virtual address of the memory reference that triggered the watchpoint, and the
1973 \fBsi_code\fR field contains one of \fBTRAP_RWATCH\fR, \fBTRAP_WWATCH\fR, or
1974 \fBTRAP_XWATCH\fR, indicating read, write, or execute access, respectively. The
1975 \fBsi_trapafter\fR field is zero unless \fBWA_TRAPAFTER\fR is in effect for
1976 this watched area; non-zero indicates that the current instruction is not the
1977 instruction that incurred the watchpoint trap. The \fBsi_pc\fR field contains
1978 the virtual address of the instruction that incurred the trap.
1979 .sp
1980 .LP
1981 A watchpoint trap may be triggered while executing a system call that makes
1982 reference to the traced process's memory. The lwp that is executing the system
1983 call incurs the watchpoint trap while still in the system call. If it stops as
1984 a result, the \fBlwpstatus\fR structure contains the system call number and its
1985 arguments. If the lwp does not stop, or if it is set running again without
1986 clearing the signal or fault, the system call fails with \fBEFAULT\fR. If
1987 \fBWA_TRAPAFTER\fR was specified, the memory reference will have completed and
1988 the memory will have been modified (if the access was a write access) when the
1989 watchpoint trap occurs.
1990 .sp
1991 .LP
1992 If more than one of \fBWA_READ\fR, \fBWA_WRITE\fR, and \fBWA_EXEC\fR is
1993 specified for a watched area, and a single instruction incurs more than one of
1994 the specified types, only one is reported when the watchpoint trap occurs. The
1995 precedence is \fBWA_EXEC\fR, \fBWA_READ\fR, \fBWA_WRITE\fR (\fBWA_EXEC\fR and
1996 \fBWA_READ\fR take precedence over \fBWA_WRITE\fR), unless \fBWA_TRAPAFTER\fR
1997 was specified, in which case it is \fBWA_WRITE\fR, \fBWA_READ\fR, \fBWA_EXEC\fR
1998 (\fBWA_WRITE\fR takes precedence).
1999 .sp
2000 .LP
2001 \fBPCWATCH\fR fails with \fBEINVAL\fR if an attempt is made to specify
2002 overlapping watched areas or if \fBpr_wflags\fR contains flags other than those
2003 specified above. It fails with \fBENOMEM\fR if an attempt is made to establish
2004 more watched areas than the system can support (the system can support
2005 thousands).
2006 .sp
2007 .LP
2008 The child of a \fBvfork\fR(2) borrows the parent's address space. When a
2009 \fBvfork\fR(2) is executed by a traced process, all watched areas established
2010 for the parent are suspended until the child terminates or performs an
2011 \fBexec\fR(2). Any watched areas established independently in the child are
2012 cancelled when the parent resumes after the child's termination or
2013 \fBexec\fR(2). \fBPCWATCH\fR fails with \fBEBUSY\fR if applied to the parent of
2014 a \fBvfork\fR(2) before the child has terminated or performed an \fBexec\fR(2).
2015 The \fBPR_VFORKP\fR flag is set in the \fBpstatus\fR structure for such a
2016 parent process.
2017 .sp
2018 .LP
2019 Certain accesses of the traced process's address space by the operating system
2020 are immune to watchpoints. The initial construction of a signal stack frame
2021 when a signal is delivered to an lwp will not trigger a watchpoint trap even if
2022 the new frame covers watched areas of the stack. Once the signal handler is
2023 entered, watchpoint traps occur normally. On SPARC based machines, register
2024 window overflow and underflow will not trigger watchpoint traps, even if the
2025 register window save areas cover watched areas of the stack.
2026 .sp
2027 .LP
2028 Watched areas are not inherited by child processes, even if the traced
2029 process's inherit-on-fork mode, \fBPR_FORK\fR, is set (see \fBPCSET\fR, below).
2030 All watched areas are cancelled when the traced process performs a successful
2031 \fBexec\fR(2).
2032 .SS "PCSET PCUNSET"
2033 .LP
2034 \fBPCSET\fR sets one or more modes of operation for the traced process.
2035 \fBPCUNSET\fR unsets these modes. The modes to be set or unset are specified by
2036 flags in an operand \fBlong\fR in the control message:
2037 .sp
2038 .ne 2
2039 .na
2040 \fB\fBPR_FORK\fR\fR
2041 .ad
2042 .RS 13n
2043 (inherit-on-fork): When set, the process's tracing flags and its
2044 inherit-on-fork mode are inherited by the child of a \fBfork\fR(2),
2045 \fBfork1\fR(2), or \fBvfork\fR(2). When unset, child processes start with all
2046 tracing flags cleared.
2047 .RE
2048
2049 .sp
2050 .ne 2
2051 .na
2052 \fB\fBPR_RLC\fR\fR
2053 .ad
2054 .RS 13n
2055 (run-on-last-close): When set and the last writable \fB/proc\fR file descriptor
2056 referring to the traced process or any of its lwps is closed, all of the
2057 process's tracing flags and watched areas are cleared, any outstanding stop
2058 directives are canceled, and if any lwps are stopped on events of interest,
2059 they are set running as though \fBPCRUN\fR had been applied to them. When
2060 unset, the process's tracing flags and watched areas are retained and lwps are
2061 not set running on last close.
2062 .RE
2063
2064 .sp
2065 .ne 2
2066 .na
2067 \fB\fBPR_KLC\fR\fR
2068 .ad
2069 .RS 13n
2070 (kill-on-last-close): When set and the last writable \fB/proc\fR file
2071 descriptor referring to the traced process or any of its lwps is closed, the
2072 process is terminated with \fBSIGKILL\fR.
2073 .RE
2074
2075 .sp
2076 .ne 2
2077 .na
2078 \fB\fBPR_ASYNC\fR\fR
2079 .ad
2080 .RS 13n
2081 (asynchronous-stop): When set, a stop on an event of interest by one lwp does
2082 not directly affect any other lwp in the process. When unset and an lwp stops
2083 on an event of interest other than \fBPR_REQUESTED\fR, all other lwps in the
2084 process are directed to stop.
2085 .RE
2086
2087 .sp
2088 .ne 2
2089 .na
2090 \fB\fBPR_MSACCT\fR\fR
2091 .ad
2092 .RS 13n
2093 (microstate accounting): Microstate accounting is now continuously enabled.
2094 This flag is deprecated and no longer has any effect upon microstate
2095 accounting. Applications may toggle this flag; however, microstate accounting
2096 will remain enabled regardless.
2097 .RE
2098
2099 .sp
2100 .ne 2
2101 .na
2102 \fB\fBPR_MSFORK\fR\fR
2103 .ad
2104 .RS 13n
2105 (inherit microstate accounting): All processes now inherit microstate
2106 accounting, as it is continuously enabled. This flag has been deprecated and
2107 its use no longer has any effect upon the behavior of microstate accounting.
2108 .RE
2109
2110 .sp
2111 .ne 2
2112 .na
2113 \fB\fBPR_BPTADJ\fR\fR
2114 .ad
2115 .RS 13n
2116 (breakpoint trap pc adjustment): On x86-based machines, a breakpoint trap
2117 leaves the program counter (the \fBEIP\fR) referring to the breakpointed
2118 instruction plus one byte. When \fBPR_BPTADJ\fR is set, the system will adjust
2119 the program counter back to the location of the breakpointed instruction when
2120 the lwp stops on a breakpoint. This flag has no effect on SPARC based machines,
2121 where breakpoint traps leave the program counter referring to the breakpointed
2122 instruction.
2123 .RE
2124
2125 .sp
2126 .ne 2
2127 .na
2128 \fB\fBPR_PTRACE\fR\fR
2129 .ad
2130 .RS 13n
2131 (ptrace-compatibility): When set, a stop on an event of interest by the traced
2132 process is reported to the parent of the traced process by \fBwait\fR(3C),
2133 \fBSIGTRAP\fR is sent to the traced process when it executes a successful
2134 \fBexec\fR(2), setuid/setgid flags are not honored for execs performed by the
2135 traced process, any exec of an object file that the traced process cannot read
2136 fails, and the process dies when its parent dies. This mode is deprecated; it
2137 is provided only to allow \fBptrace\fR(3C) to be implemented as a library
2138 function using \fB/proc\fR.
2139 .RE
2140
2141 .sp
2142 .LP
2143 It is an error (\fBEINVAL\fR) to specify flags other than those described above
2144 or to apply these operations to a system process. The current modes are
2145 reported in the \fBpr_flags\fR field of \fB/proc/\fR\fIpid\fR\fB/status\fR and
2146 \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwp\fR\fB/lwpstatus\fR.
2147 .SS "PCSREG"
2148 .LP
2149 Set the general registers for the specific or representative lwp according to
2150 the operand \fBprgregset_t\fR structure.
2151 .sp
2152 .LP
2153 On SPARC based systems, only the condition-code bits of the processor-status
2154 register (R_PSR) of SPARC V8 (32-bit) processes can be modified by
2155 \fBPCSREG\fR. Other privileged registers cannot be modified at all.
2156 .sp
2157 .LP
2158 On x86-based systems, only certain bits of the flags register (EFL) can be
2159 modified by \fBPCSREG\fR: these include the condition codes, direction-bit, and
2160 overflow-bit.
2161 .sp
2162 .LP
2163 \fBPCSREG\fR fails with \fBEBUSY\fR if the lwp is not stopped on an event of
2164 interest.
2165 .SS "PCSVADDR"
2166 .LP
2167 Set the address at which execution will resume for the specific or
2168 representative lwp from the operand \fBlong\fR. On SPARC based systems, both
2169 %pc and %npc are set, with %npc set to the instruction following the virtual
2170 address. On x86-based systems, only %eip is set. \fBPCSVADDR\fR fails with
2171 \fBEBUSY\fR if the lwp is not stopped on an event of interest.
2172 .SS "PCSFPREG"
2173 .LP
2174 Set the floating-point registers for the specific or representative lwp
2175 according to the operand \fBprfpregset_t\fR structure. An error (\fBEINVAL\fR)
2176 is returned if the system does not support floating-point operations (no
2177 floating-point hardware and the system does not emulate floating-point machine
2178 instructions). \fBPCSFPREG\fR fails with \fBEBUSY\fR if the lwp is not stopped
2179 on an event of interest.
2180 .SS "PCSXREG"
2181 .LP
2182 Set the extra state registers for the specific or representative lwp according
2183 to the architecture-dependent operand \fBprxregset_t\fR structure. An error
2184 (\fBEINVAL\fR) is returned if the system does not support extra state
2185 registers. \fBPCSXREG\fR fails with \fBEBUSY\fR if the lwp is not stopped on an
2186 event of interest.
2187 .SS "PCSASRS"
2188 .LP
2189 Set the ancillary state registers for the specific or representative lwp
2190 according to the SPARC V9 platform-dependent operand \fBasrset_t\fR structure.
2191 An error (\fBEINVAL\fR) is returned if either the target process or the
2192 controlling process is not a 64-bit SPARC V9 process. Most of the ancillary
2193 state registers are privileged registers that cannot be modified. Only those
2194 that can be modified are set; all others are silently ignored. \fBPCSASRS\fR
2195 fails with \fBEBUSY\fR if the lwp is not stopped on an event of interest.
2196 .SS "PCAGENT"
2197 .LP
2198 Create an agent lwp in the controlled process with register values from the
2199 operand \fBprgregset_t\fR structure (see \fBPCSREG\fR, above). The agent lwp is
2200 created in the stopped state showing \fBPR_REQUESTED\fR and with its held
2201 signal set (the signal mask) having all signals except \fBSIGKILL\fR and
2202 \fBSIGSTOP\fR blocked.
2203 .sp
2204 .LP
2205 The \fBPCAGENT\fR operation fails with \fBEBUSY\fR unless the process is fully
2206 stopped via \fB/proc\fR, that is, unless all of the lwps in the process are
2207 stopped either on events of interest or on \fBPR_SUSPENDED\fR, or are stopped
2208 on \fBPR_JOBCONTROL\fR and have been directed to stop via \fBPCDSTOP\fR. It
2209 fails with \fBEBUSY\fR if an agent lwp already exists. It fails with
2210 \fBENOMEM\fR if system resources for creating new lwps have been exhausted.
2211 .sp
2212 .LP
2213 Any \fBPCRUN\fR operation applied to the process control file or to the control
2214 file of an lwp other than the agent lwp fails with \fBEBUSY\fR as long as the
2215 agent lwp exists. The agent lwp must be caused to terminate by executing the
2216 \fBSYS_lwp_exit\fR system call trap before the process can be restarted.
2217 .sp
2218 .LP
2219 Once the agent lwp is created, its lwp-ID can be found by reading the process
2220 status file. To facilitate opening the agent lwp's control and status files,
2221 the directory name \fB/propc/\fR\fIpid\fR\fB/lwp/agent\fR is accepted for
2222 lookup operations as an invisible alias for
2223 \fB/proc/\fR\fIpid\fR\fB/lwp/\fR\fIlwpid,\fR \fIlwpid\fR being the lwp-ID of
2224 the agent lwp (invisible in the sense that the name ``agent'' does not appear
2225 in a directory listing of \fB/proc/\fR\fIpid\fR\fB/lwp\fR obtained from
2226 \fBls\fR(1), \fBgetdents\fR(2), or \fBreaddir\fR(3C)).
2227 .sp
2228 .LP
2229 The purpose of the agent lwp is to perform operations in the controlled process
2230 on behalf of the controlling process: to gather information not directly
2231 available via \fB/proc\fR files, or in general to make the process change state
2232 in ways not directly available via \fB/proc\fR control operations. To make use
2233 of an agent lwp, the controlling process must be capable of making it execute
2234 system calls (specifically, the \fBSYS_lwp_exit\fR system call trap). The
2235 register values given to the agent lwp on creation are typically the registers
2236 of the representative lwp, so that the agent lwp can use its stack.
2237 .sp
2238 .LP
2239 If the controlling process neglects to force the agent lwp to execute the
2240 \fBSYS_lwp_exit\fR system call (due to either logic error or fatal failure on
2241 the part of the controlling process), the agent lwp will remain in the target
2242 process. For purposes of being able to debug these otherwise rogue agents,
2243 information as to the creator of the agent lwp is reflected in that lwp's
2244 \fBspymaster\fR file in \fB/proc\fR. Should the target process generate a core
2245 dump with the agent lwp in place, this information will be available via the
2246 \fBNT_SPYMASTER\fR note in the core file (see \fBcore\fR(4)).
2247 .sp
2248 .LP
2249 The agent lwp is not allowed to execute any variation of the \fBSYS_fork\fR or
2250 \fBSYS_exec\fR system call traps. Attempts to do so yield \fBENOTSUP\fR to the
2251 agent lwp.
2252 .sp
2253 .LP
2254 Symbolic constants for system call trap numbers like \fBSYS_lwp_exit\fR and
2255 \fBSYS_lwp_create\fR can be found in the header file <\fBsys/syscall.h\fR>.
2256 .SS "PCREAD PCWRITE"
2257 .LP
2258 Read or write the target process's address space via a \fBpriovec\fR structure
2259 operand:
2260 .sp
2261 .in +2
2262 .nf
2263 typedef struct priovec {
2264 void *pio_base; /* buffer in controlling process */
2265 size_t pio_len; /* size of read/write request in bytes */
2266 off_t pio_offset; /* virtual address in target process */
2267 } priovec_t;
2268 .fi
2269 .in -2
2270
2271 .sp
2272 .LP
2273 These operations have the same effect as \fBpread\fR(2) and \fBpwrite\fR(2),
2274 respectively, of the target process's address space file. The difference is
2275 that more than one \fBPCREAD\fR or \fBPCWRITE\fR control operation can be
2276 written to the control file at once, and they can be interspersed with other
2277 control operations in a single write to the control file. This is useful, for
2278 example, when planting many breakpoint instructions in the process's address
2279 space, or when stepping over a breakpointed instruction. Unlike \fBpread\fR(2)
2280 and \fBpwrite\fR(2), no provision is made for partial reads or writes; if the
2281 operation cannot be performed completely, it fails with \fBEIO\fR.
2282 .SS "PCNICE"
2283 .LP
2284 The traced process's \fBnice\fR(2) value is incremented by the amount in the
2285 operand \fBlong\fR. Only a process with the {\fBPRIV_PROC_PRIOCNTL\fR}
2286 privilege asserted in its effective set can better a process's priority in this
2287 way, but any user may lower the priority. This operation is not meaningful for
2288 all scheduling classes.
2289 .SS "PCSCRED"
2290 .LP
2291 Set the target process credentials to the values contained in the
2292 \fBprcred_t\fR structure operand (see \fB/proc/\fR\fIpid\fR\fB/cred\fR). The
2293 effective, real, and saved user-IDs and group-IDs of the target process are
2294 set. The target process's supplementary groups are not changed; the
2295 \fBpr_ngroups\fR and \fBpr_groups\fR members of the structure operand are
2296 ignored. Only the privileged processes can perform this operation; for all
2297 others it fails with \fBEPERM\fR.
2298 .SS "PCSCREDX"
2299 .LP
2300 Operates like \fBPCSCRED\fR but also sets the supplementary groups; the length
2301 of the data written with this control operation should be "sizeof
2302 (\fBprcred_t\fR) + sizeof (\fBgid_t)\fR * (#groups - 1)".
2303 .SS "PCSPRIV"
2304 .LP
2305 Set the target process privilege to the values contained in the \fBprpriv_t\fR
2306 operand (see \fB/proc/pid/priv\fR). The effective, permitted, inheritable, and
2307 limit sets are all changed. Privilege flags can also be set. The process is
2308 made privilege aware unless it can relinquish privilege awareness. See
2309 \fBprivileges\fR(5).
2310 .sp
2311 .LP
2312 The limit set of the target process cannot be grown. The other privilege sets
2313 must be subsets of the intersection of the effective set of the calling process
2314 with the new limit set of the target process or subsets of the original values
2315 of the sets in the target process.
2316 .sp
2317 .LP
2318 If any of the above restrictions are not met, \fBEPERM\fR is returned. If the
2319 structure written is improperly formatted, \fBEINVAL\fR is returned.
2320 .SH PROGRAMMING NOTES
2321 .LP
2322 For security reasons, except for the \fBpsinfo\fR, \fBusage\fR, \fBlpsinfo\fR,
2323 \fBlusage\fR, \fBlwpsinfo\fR, and \fBlwpusage\fR files, which are
2324 world-readable, and except for privileged processes, an open of a \fB/proc\fR
2325 file fails unless both the user-ID and group-ID of the caller match those of
2326 the traced process and the process's object file is readable by the caller. The
2327 effective set of the caller is a superset of both the inheritable and the
2328 permitted set of the target process. The limit set of the caller is a superset
2329 of the limit set of the target process. Except for the world-readable files
2330 just mentioned, files corresponding to setuid and setgid processes can be
2331 opened only by the appropriately privileged process.
2332 .sp
2333 .LP
2334 A process that is missing the basic privilege {\fBPRIV_PROC_INFO\fR} cannot see
2335 any processes under \fB/proc\fR that it cannot send a signal to.
2336 .sp
2337 .LP
2338 A process that has {\fBPRIV_PROC_OWNER\fR} asserted in its effective set can
2339 open any file for reading. To manipulate or control a process, the controlling
2340 process must have at least as many privileges in its effective set as the
2341 target process has in its effective, inheritable, and permitted sets. The limit
2342 set of the controlling process must be a superset of the limit set of the
2343 target process. Additional restrictions apply if any of the uids of the target
2344 process are 0. See \fBprivileges\fR(5).
2345 .sp
2346 .LP
2347 Even if held by a privileged process, an open process or lwp file descriptor
2348 (other than file descriptors for the world-readable files) becomes invalid if
2349 the traced process performs an \fBexec\fR(2) of a setuid/setgid object file or
2350 an object file that the traced process cannot read. Any operation performed on
2351 an invalid file descriptor, except \fBclose\fR(2), fails with \fBEAGAIN\fR. In
2352 this situation, if any tracing flags are set and the process or any lwp file
2353 descriptor is open for writing, the process will have been directed to stop and
2354 its run-on-last-close flag will have been set (see \fBPCSET\fR). This enables a
2355 controlling process (if it has permission) to reopen the \fB/proc\fR files to
2356 get new valid file descriptors, close the invalid file descriptors, unset the
2357 run-on-last-close flag (if desired), and proceed. Just closing the invalid file
2358 descriptors causes the traced process to resume execution with all tracing
2359 flags cleared. Any process not currently open for writing via \fB/proc\fR, but
2360 that has left-over tracing flags from a previous open, and that executes a
2361 setuid/setgid or unreadable object file, will not be stopped but will have all
2362 its tracing flags cleared.
2363 .sp
2364 .LP
2365 To wait for one or more of a set of processes or lwps to stop or terminate,
2366 \fB/proc\fR file descriptors (other than those obtained by opening the
2367 \fBcwd\fR or \fBroot\fR directories or by opening files in the \fBfd\fR or
2368 \fBobject\fR directories) can be used in a \fBpoll\fR(2) system call. When
2369 requested and returned, either of the polling events \fBPOLLPRI\fR or
2370 \fBPOLLWRNORM\fR indicates that the process or lwp stopped on an event of
2371 interest. Although they cannot be requested, the polling events \fBPOLLHUP\fR,
2372 \fBPOLLERR\fR, and \fBPOLLNVAL\fR may be returned. \fBPOLLHUP\fR indicates that
2373 the process or lwp has terminated. \fBPOLLERR\fR indicates that the file
2374 descriptor has become invalid. \fBPOLLNVAL\fR is returned immediately if
2375 \fBPOLLPRI\fR or \fBPOLLWRNORM\fR is requested on a file descriptor referring
2376 to a system process (see \fBPCSTOP\fR). The requested events may be empty to
2377 wait simply for termination.
2378 .SH FILES
2379 .ne 2
2380 .na
2381 \fB\fB/proc\fR\fR
2382 .ad
2383 .sp .6
2384 .RS 4n
2385 directory (list of processes)
2386 .RE
2387
2388 .sp
2389 .ne 2
2390 .na
2391 \fB\fB/proc/\fIpid\fR\fR\fR
2392 .ad
2393 .sp .6
2394 .RS 4n
2395 specific process directory
2396 .RE
2397
2398 .sp
2399 .ne 2
2400 .na
2401 \fB\fB/proc/self\fR\fR
2402 .ad
2403 .sp .6
2404 .RS 4n
2405 alias for a process's own directory
2406 .RE
2407
2408 .sp
2409 .ne 2
2410 .na
2411 \fB\fB/proc/\fIpid\fR/as\fR\fR
2412 .ad
2413 .sp .6
2414 .RS 4n
2415 address space file
2416 .RE
2417
2418 .sp
2419 .ne 2
2420 .na
2421 \fB\fB/proc/\fIpid\fR/ctl\fR\fR
2422 .ad
2423 .sp .6
2424 .RS 4n
2425 process control file
2426 .RE
2427
2428 .sp
2429 .ne 2
2430 .na
2431 \fB\fB/proc/\fIpid\fR/status\fR\fR
2432 .ad
2433 .sp .6
2434 .RS 4n
2435 process status
2436 .RE
2437
2438 .sp
2439 .ne 2
2440 .na
2441 \fB\fB/proc/\fIpid\fR/lstatus\fR\fR
2442 .ad
2443 .sp .6
2444 .RS 4n
2445 array of lwp status structs
2446 .RE
2447
2448 .sp
2449 .ne 2
2450 .na
2451 \fB\fB/proc/\fIpid\fR/psinfo\fR\fR
2452 .ad
2453 .sp .6
2454 .RS 4n
2455 process \fBps\fR(1) info
2456 .RE
2457
2458 .sp
2459 .ne 2
2460 .na
2461 \fB\fB/proc/\fIpid\fR/lpsinfo\fR\fR
2462 .ad
2463 .sp .6
2464 .RS 4n
2465 array of lwp \fBps\fR(1) info structs
2466 .RE
2467
2468 .sp
2469 .ne 2
2470 .na
2471 \fB\fB/proc/\fIpid\fR/map\fR\fR
2472 .ad
2473 .sp .6
2474 .RS 4n
2475 address space map
2476 .RE
2477
2478 .sp
2479 .ne 2
2480 .na
2481 \fB\fB/proc/\fIpid\fR/xmap\fR\fR
2482 .ad
2483 .sp .6
2484 .RS 4n
2485 extended address space map
2486 .RE
2487
2488 .sp
2489 .ne 2
2490 .na
2491 \fB\fB/proc/\fIpid\fR/rmap\fR\fR
2492 .ad
2493 .sp .6
2494 .RS 4n
2495 reserved address map
2496 .RE
2497
2498 .sp
2499 .ne 2
2500 .na
2501 \fB\fB/proc/\fIpid\fR/cred\fR\fR
2502 .ad
2503 .sp .6
2504 .RS 4n
2505 process credentials
2506 .RE
2507
2508 .sp
2509 .ne 2
2510 .na
2511 \fB\fB/proc/\fIpid\fR/priv\fR\fR
2512 .ad
2513 .sp .6
2514 .RS 4n
2515 process privileges
2516 .RE
2517
2518 .sp
2519 .ne 2
2520 .na
2521 \fB\fB/proc/\fIpid\fR/sigact\fR\fR
2522 .ad
2523 .sp .6
2524 .RS 4n
2525 process signal actions
2526 .RE
2527
2528 .sp
2529 .ne 2
2530 .na
2531 \fB\fB/proc/\fIpid\fR/auxv\fR\fR
2532 .ad
2533 .sp .6
2534 .RS 4n
2535 process aux vector
2536 .RE
2537
2538 .sp
2539 .ne 2
2540 .na
2541 \fB\fB/proc/\fIpid\fR/ldt\fR\fR
2542 .ad
2543 .sp .6
2544 .RS 4n
2545 process \fBLDT\fR (x86 only)
2546 .RE
2547
2548 .sp
2549 .ne 2
2550 .na
2551 \fB\fB/proc/\fIpid\fR/usage\fR\fR
2552 .ad
2553 .sp .6
2554 .RS 4n
2555 process usage
2556 .RE
2557
2558 .sp
2559 .ne 2
2560 .na
2561 \fB\fB/proc/\fIpid\fR/lusage\fR\fR
2562 .ad
2563 .sp .6
2564 .RS 4n
2565 array of lwp usage structs
2566 .RE
2567
2568 .sp
2569 .ne 2
2570 .na
2571 \fB\fB/proc/\fIpid\fR/path\fR\fR
2572 .ad
2573 .sp .6
2574 .RS 4n
2575 symbolic links to process open files
2576 .RE
2577
2578 .sp
2579 .ne 2
2580 .na
2581 \fB\fB/proc/\fIpid\fR/pagedata\fR\fR
2582 .ad
2583 .sp .6
2584 .RS 4n
2585 process page data
2586 .RE
2587
2588 .sp
2589 .ne 2
2590 .na
2591 \fB\fB/proc/\fIpid\fR/watch\fR\fR
2592 .ad
2593 .sp .6
2594 .RS 4n
2595 active watchpoints
2596 .RE
2597
2598 .sp
2599 .ne 2
2600 .na
2601 \fB\fB/proc/\fIpid\fR/cwd\fR\fR
2602 .ad
2603 .sp .6
2604 .RS 4n
2605 alias for the current working directory
2606 .RE
2607
2608 .sp
2609 .ne 2
2610 .na
2611 \fB\fB/proc/\fIpid\fR/root\fR\fR
2612 .ad
2613 .sp .6
2614 .RS 4n
2615 alias for the root directory
2616 .RE
2617
2618 .sp
2619 .ne 2
2620 .na
2621 \fB\fB/proc/\fIpid\fR/fd\fR\fR
2622 .ad
2623 .sp .6
2624 .RS 4n
2625 directory (list of open files)
2626 .RE
2627
2628 .sp
2629 .ne 2
2630 .na
2631 \fB\fB/proc/\fIpid\fR/fd/*\fR\fR
2632 .ad
2633 .sp .6
2634 .RS 4n
2635 aliases for process's open files
2636 .RE
2637
2638 .sp
2639 .ne 2
2640 .na
2641 \fB\fB/proc/\fIpid\fR/object\fR\fR
2642 .ad
2643 .sp .6
2644 .RS 4n
2645 directory (list of mapped files)
2646 .RE
2647
2648 .sp
2649 .ne 2
2650 .na
2651 \fB\fB/proc/\fIpid\fR/object/a.out\fR\fR
2652 .ad
2653 .sp .6
2654 .RS 4n
2655 alias for process's executable file
2656 .RE
2657
2658 .sp
2659 .ne 2
2660 .na
2661 \fB\fB/proc/\fIpid\fR/object/*\fR\fR
2662 .ad
2663 .sp .6
2664 .RS 4n
2665 aliases for other mapped files
2666 .RE
2667
2668 .sp
2669 .ne 2
2670 .na
2671 \fB\fB/proc/\fIpid\fR/lwp\fR\fR
2672 .ad
2673 .sp .6
2674 .RS 4n
2675 directory (list of lwps)
2676 .RE
2677
2678 .sp
2679 .ne 2
2680 .na
2681 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR\fR\fR
2682 .ad
2683 .sp .6
2684 .RS 4n
2685 specific lwp directory
2686 .RE
2687
2688 .sp
2689 .ne 2
2690 .na
2691 \fB\fB/proc/\fIpid\fR/lwp/agent\fR\fR
2692 .ad
2693 .sp .6
2694 .RS 4n
2695 alias for the agent lwp directory
2696 .RE
2697
2698 .sp
2699 .ne 2
2700 .na
2701 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/lwpctl\fR\fR
2702 .ad
2703 .sp .6
2704 .RS 4n
2705 lwp control file
2706 .RE
2707
2708 .sp
2709 .ne 2
2710 .na
2711 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/lwpstatus\fR\fR
2712 .ad
2713 .sp .6
2714 .RS 4n
2715 lwp status
2716 .RE
2717
2718 .sp
2719 .ne 2
2720 .na
2721 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/lwpsinfo\fR\fR
2722 .ad
2723 .sp .6
2724 .RS 4n
2725 lwp \fBps\fR(1) info
2726 .RE
2727
2728 .sp
2729 .ne 2
2730 .na
2731 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/lwpusage\fR\fR
2732 .ad
2733 .sp .6
2734 .RS 4n
2735 lwp usage
2736 .RE
2737
2738 .sp
2739 .ne 2
2740 .na
2741 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/gwindows\fR\fR
2742 .ad
2743 .sp .6
2744 .RS 4n
2745 register windows (SPARC only)
2746 .RE
2747
2748 .sp
2749 .ne 2
2750 .na
2751 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/xregs\fR\fR
2752 .ad
2753 .sp .6
2754 .RS 4n
2755 extra state registers
2756 .RE
2757
2758 .sp
2759 .ne 2
2760 .na
2761 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/asrs\fR\fR
2762 .ad
2763 .sp .6
2764 .RS 4n
2765 ancillary state registers (SPARC V9 only)
2766 .RE
2767
2768 .sp
2769 .ne 2
2770 .na
2771 \fB\fB/proc/\fIpid\fR/lwp/\fIlwpid\fR/spymaster\fR\fR
2772 .ad
2773 .sp .6
2774 .RS 4n
2775 For an agent LWP, the controlling process
2776 .RE
2777
2778 .SH SEE ALSO
2779 .LP
2780 \fBls\fR(1), \fBps\fR(1), \fBchroot\fR(1M), \fBalarm\fR(2), \fBbrk\fR(2),
2781 \fBchdir\fR(2), \fBchroot\fR(2), \fBclose\fR(2), \fBcreat\fR(2), \fBdup\fR(2),
2782 \fBexec\fR(2), \fBfcntl\fR(2), \fBfork\fR(2), \fBfork1\fR(2), \fBfstat\fR(2),
2783 \fBgetdents\fR(2), \fBgetustack\fR(2), \fBkill\fR(2), \fBlseek\fR(2),
2784 \fBmmap\fR(2), \fBnice\fR(2), \fBopen\fR(2), \fBpoll\fR(2), \fBpread\fR(2),
2785 \fBptrace\fR(3C), \fBpwrite\fR(2), \fBread\fR(2), \fBreadlink\fR(2),
2786 \fBreadv\fR(2), \fBshmget\fR(2), \fBsigaction\fR(2), \fBsigaltstack\fR(2),
2787 \fBvfork\fR(2), \fBwrite\fR(2), \fBwritev\fR(2), \fB_stack_grow\fR(3C),
2788 \fBreaddir\fR(3C), \fBpthread_create\fR(3C), \fBpthread_join\fR(3C),
2789 \fBsiginfo.h\fR(3HEAD), \fBsignal.h\fR(3HEAD), \fBthr_create\fR(3C),
2790 \fBthr_join\fR(3C), \fBtypes32.h\fR(3HEAD), \fBucontext.h\fR(3HEAD),
2791 \fBwait\fR(3C), \fBcontract\fR(4), \fBcore\fR(4), \fBprocess\fR(4),
2792 \fBlfcompile\fR(5), \fBprivileges\fR(5), \fBsecurity-flags\fR(5)
2793 .SH DIAGNOSTICS
2794 .LP
2795 Errors that can occur in addition to the errors normally associated with file
2796 system access:
2797 .sp
2798 .ne 2
2799 .na
2800 \fB\fBE2BIG\fR\fR
2801 .ad
2802 .RS 13n
2803 Data to be returned in a \fBread\fR(2) of the page data file exceeds the size
2804 of the read buffer provided by the caller.
2805 .RE
2806
2807 .sp
2808 .ne 2
2809 .na
2810 \fB\fBEACCES\fR\fR
2811 .ad
2812 .RS 13n
2813 An attempt was made to examine a process that ran under a different uid than
2814 the controlling process and {\fBPRIV_PROC_OWNER\fR} was not asserted in the
2815 effective set.
2816 .RE
2817
2818 .sp
2819 .ne 2
2820 .na
2821 \fB\fBEAGAIN\fR\fR
2822 .ad
2823 .RS 13n
2824 The traced process has performed an \fBexec\fR(2) of a setuid/setgid object
2825 file or of an object file that it cannot read; all further operations on the
2826 process or lwp file descriptor (except \fBclose\fR(2)) elicit this error.
2827 .RE
2828
2829 .sp
2830 .ne 2
2831 .na
2832 \fB\fBEBUSY\fR\fR
2833 .ad
2834 .RS 13n
2835 \fBPCSTOP\fR, \fBPCDSTOP\fR, \fBPCWSTOP\fR, or \fBPCTWSTOP\fR was applied to a
2836 system process; an exclusive \fBopen\fR(2) was attempted on a \fB/proc\fR file
2837 for a process already open for writing; \fBPCRUN\fR, \fBPCSREG\fR,
2838 \fBPCSVADDR\fR, \fBPCSFPREG\fR, or \fBPCSXREG\fR was applied to a process or
2839 lwp not stopped on an event of interest; an attempt was made to mount
2840 \fB/proc\fR when it was already mounted; \fBPCAGENT\fR was applied to a process
2841 that was not fully stopped or that already had an agent lwp.
2842 .RE
2843
2844 .sp
2845 .ne 2
2846 .na
2847 \fB\fBEINVAL\fR\fR
2848 .ad
2849 .RS 13n
2850 In general, this means that some invalid argument was supplied to a system
2851 call. A non-exhaustive list of conditions eliciting this error includes: a
2852 control message operation code is undefined; an out-of-range signal number was
2853 specified with \fBPCSSIG\fR, \fBPCKILL\fR, or \fBPCUNKILL\fR; \fBSIGKILL\fR was
2854 specified with \fBPCUNKILL\fR; \fBPCSFPREG\fR was applied on a system that does
2855 not support floating-point operations; \fBPCSXREG\fR was applied on a system
2856 that does not support extra state registers.
2857 .RE
2858
2859 .sp
2860 .ne 2
2861 .na
2862 \fB\fBEINTR\fR\fR
2863 .ad
2864 .RS 13n
2865 A signal was received by the controlling process while waiting for the traced
2866 process or lwp to stop via \fBPCSTOP\fR, \fBPCWSTOP\fR, or \fBPCTWSTOP\fR.
2867 .RE
2868
2869 .sp
2870 .ne 2
2871 .na
2872 \fB\fBEIO\fR\fR
2873 .ad
2874 .RS 13n
2875 A \fBwrite\fR(2) was attempted at an illegal address in the traced process.
2876 .RE
2877
2878 .sp
2879 .ne 2
2880 .na
2881 \fB\fBENOENT\fR\fR
2882 .ad
2883 .RS 13n
2884 The traced process or lwp has terminated after being opened. The basic
2885 privilege {\fBPRIV_PROC_INFO\fR} is not asserted in the effective set of the
2886 calling process and the calling process cannot send a signal to the target
2887 process.
2888 .RE
2889
2890 .sp
2891 .ne 2
2892 .na
2893 \fB\fBENOMEM\fR\fR
2894 .ad
2895 .RS 13n
2896 The system-imposed limit on the number of page data file descriptors was
2897 reached on an open of \fB/proc/\fR\fIpid\fR\fB/pagedata\fR; an attempt was made
2898 with \fBPCWATCH\fR to establish more watched areas than the system can support;
2899 the \fBPCAGENT\fR operation was issued when the system was out of resources for
2900 creating lwps.
2901 .RE
2902
2903 .sp
2904 .ne 2
2905 .na
2906 \fB\fBENOSYS\fR\fR
2907 .ad
2908 .RS 13n
2909 An attempt was made to perform an unsupported operation (such as
2910 \fBcreat\fR(2), \fBlink\fR(2), or \fBunlink\fR(2)) on an entry in \fB/proc\fR.
2911 .RE
2912
2913 .sp
2914 .ne 2
2915 .na
2916 \fB\fBEOVERFLOW\fR\fR
2917 .ad
2918 .RS 13n
2919 A 32-bit controlling process attempted to read or write the \fBas\fR file or
2920 attempted to read the \fBmap\fR, \fBrmap\fR, or \fBpagedata\fR file of a 64-bit
2921 target process. A 32-bit controlling process attempted to apply one of the
2922 control operations \fBPCSREG\fR, \fBPCSXREG\fR, \fBPCSVADDR\fR, \fBPCWATCH\fR,
2923 \fBPCAGENT\fR, \fBPCREAD\fR, \fBPCWRITE\fR to a 64-bit target process.
2924 .RE
2925
2926 .sp
2927 .ne 2
2928 .na
2929 \fB\fBEPERM\fR\fR
2930 .ad
2931 .RS 13n
2932 The process that issued the \fBPCSCRED\fR or \fBPCSCREDX\fR operation did not
2933 have the {\fBPRIV_PROC_SETID\fR} privilege asserted in its effective set, or
2934 the process that issued the \fBPCNICE\fR operation did not have the
2935 {\fBPRIV_PROC_PRIOCNTL\fR} in its effective set.
2936 .sp
2937 An attempt was made to control a process of which the E, P, and I privilege
2938 sets were not a subset of the effective set of the controlling process or the
2939 limit set of the controlling process is not a superset of limit set of the
2940 controlled process.
2941 .sp
2942 Any of the uids of the target process are 0 or an attempt was made to change
2943 any of the uids to 0 using PCSCRED and the security policy imposed additional
2944 restrictions. See \fBprivileges\fR(5).
2945 .RE
2946
2947 .SH NOTES
2948 .LP
2949 Descriptions of structures in this document include only interesting structure
2950 elements, not filler and padding fields, and may show elements out of order for
2951 descriptive clarity. The actual structure definitions are contained in
2952 \fB<procfs.h>\fR\&.
2953 .SH BUGS
2954 .LP
2955 Because the old \fBioctl\fR(2)-based version of \fB/proc\fR is currently
2956 supported for binary compatibility with old applications, the top-level
2957 directory for a process, \fB/proc/\fR\fIpid\fR, is not world-readable, but it
2958 is world-searchable. Thus, anyone can open \fB/proc/\fR\fIpid\fR\fB/psinfo\fR
2959 even though \fBls\fR(1) applied to \fB/proc/\fR\fIpid\fR will fail for anyone
2960 but the owner or an appropriately privileged process. Support for the old
2961 \fBioctl\fR(2)-based version of \fB/proc\fR will be dropped in a future
2962 release, at which time the top-level directory for a process will be made
2963 world-readable.
2964 .sp
2965 .LP
2966 On SPARC based machines, the types \fBgregset_t\fR and \fBfpregset_t\fR defined
2967 in <\fBsys/regset.h\fR> are similar to but not the same as the types
2968 \fBprgregset_t\fR and \fBprfpregset_t\fR defined in <\fBprocfs.h\fR>.