blob: 614b85f9bf0282e48e794bb1e3260301248087e4 [file] [log] [blame]
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001/*
2 * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
3 * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
4 * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
Wichert Akkerman4dc8a2a1999-12-23 14:20:14 +00005 * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00006 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Wichert Akkerman76baf7c1999-02-19 00:21:36 +000029 */
30
31#include "defs.h"
Denys Vlasenko3454e4b2011-05-23 21:29:03 +020032#include <stdarg.h>
Wichert Akkerman76baf7c1999-02-19 00:21:36 +000033#include <sys/param.h>
34#include <fcntl.h>
Dmitry V. Levin0e946ab2015-07-17 23:56:54 +000035#include <signal.h>
Wichert Akkerman76baf7c1999-02-19 00:21:36 +000036#include <sys/resource.h>
37#include <sys/wait.h>
38#include <sys/stat.h>
39#include <pwd.h>
40#include <grp.h>
Roland McGrath70b08532004-04-09 00:25:21 +000041#include <dirent.h>
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +010042#include <sys/utsname.h>
Dmitry V. Levin882478a2013-05-13 18:43:28 +000043#ifdef HAVE_PRCTL
44# include <sys/prctl.h>
45#endif
Dmitry V. Levinfadf3792015-02-13 00:26:38 +000046
47#include "ptrace.h"
Dmitry V. Levin0e946ab2015-07-17 23:56:54 +000048#include "printsiginfo.h"
Dmitry V. Levinfadf3792015-02-13 00:26:38 +000049
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010050/* In some libc, these aren't declared. Do it ourself: */
Denys Vlasenko96d5a762008-12-29 19:13:27 +000051extern char **environ;
Denys Vlasenko418d66a2009-01-17 01:52:54 +000052extern int optind;
53extern char *optarg;
Denys Vlasenko96d5a762008-12-29 19:13:27 +000054
Luca Clementi327064b2013-07-23 00:11:35 -070055#ifdef USE_LIBUNWIND
56/* if this is true do the stack trace for every system call */
57bool stack_trace_enabled = false;
58#endif
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010059
60#if defined __NR_tkill
61# define my_tkill(tid, sig) syscall(__NR_tkill, (tid), (sig))
62#else
63 /* kill() may choose arbitrarily the target task of the process group
64 while we later wait on a that specific TID. PID process waits become
65 TID task specific waits for a process under ptrace(2). */
Denys Vlasenko978fbc92012-09-13 10:28:43 +020066# warning "tkill(2) not available, risk of strace hangs!"
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010067# define my_tkill(tid, sig) kill((tid), (sig))
68#endif
69
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +010070/* Glue for systems without a MMU that cannot provide fork() */
71#if !defined(HAVE_FORK)
72# undef NOMMU_SYSTEM
73# define NOMMU_SYSTEM 1
74#endif
75#if NOMMU_SYSTEM
76# define fork() vfork()
77#endif
78
Dmitry V. Levin23ce9e42015-02-08 13:05:53 +000079const unsigned int syscall_trap_sig = SIGTRAP | 0x80;
80
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010081cflag_t cflag = CFLAG_NONE;
82unsigned int followfork = 0;
Dmitry V. Levin23ce9e42015-02-08 13:05:53 +000083unsigned int ptrace_setoptions = PTRACE_O_TRACESYSGOOD | PTRACE_O_TRACEEXEC;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010084unsigned int xflag = 0;
85bool debug_flag = 0;
86bool Tflag = 0;
Anton Blancharda34dead2013-07-12 12:22:06 +020087bool iflag = 0;
Mark Hillse53bf232014-05-28 17:52:40 +010088bool count_wallclock = 0;
Daniel P. Berrange01997cf2013-05-13 11:30:55 +010089unsigned int qflag = 0;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010090static unsigned int tflag = 0;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010091static bool rflag = 0;
92static bool print_pid_pfx = 0;
Denys Vlasenkob51581e2012-01-29 16:53:03 +010093
94/* -I n */
95enum {
96 INTR_NOT_SET = 0,
97 INTR_ANYWHERE = 1, /* don't block/ignore any signals */
98 INTR_WHILE_WAIT = 2, /* block fatal signals while decoding syscall. default */
99 INTR_NEVER = 3, /* block fatal signals. default if '-o FILE PROG' */
100 INTR_BLOCK_TSTP_TOO = 4, /* block fatal signals and SIGTSTP (^Z) */
101 NUM_INTR_OPTS
102};
103static int opt_intr;
104/* We play with signal mask only if this mode is active: */
105#define interactive (opt_intr == INTR_WHILE_WAIT)
106
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000107/*
108 * daemonized_tracer supports -D option.
109 * With this option, strace forks twice.
110 * Unlike normal case, with -D *grandparent* process exec's,
111 * becoming a traced process. Child exits (this prevents traced process
112 * from having children it doesn't expect to have), and grandchild
113 * attaches to grandparent similarly to strace -p PID.
114 * This allows for more transparent interaction in cases
115 * when process and its parent are communicating via signals,
116 * wait() etc. Without -D, strace process gets lodged in between,
117 * disrupting parent<->child link.
118 */
119static bool daemonized_tracer = 0;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000120
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +0100121#if USE_SEIZE
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100122static int post_attach_sigstop = TCB_IGNORE_ONE_SIGSTOP;
123# define use_seize (post_attach_sigstop == 0)
124#else
125# define post_attach_sigstop TCB_IGNORE_ONE_SIGSTOP
126# define use_seize 0
127#endif
128
Michal Ludvig17f8fb32002-11-06 13:17:21 +0000129/* Sometimes we want to print only succeeding syscalls. */
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +0100130bool not_failing_only = 0;
Michal Ludvig17f8fb32002-11-06 13:17:21 +0000131
Grant Edwards8a082772011-04-07 20:25:40 +0000132/* Show path associated with fd arguments */
Dmitry V. Levin45e7b182014-08-08 23:38:26 +0000133unsigned int show_fd_path = 0;
Grant Edwards8a082772011-04-07 20:25:40 +0000134
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100135static bool detach_on_execve = 0;
Denys Vlasenko2a3d2752013-05-14 16:07:46 +0200136/* Are we "strace PROG" and need to skip detach on first execve? */
137static bool skip_one_b_execve = 0;
138/* Are we "strace PROG" and need to hide everything until execve? */
139bool hide_log_until_execve = 0;
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100140
Dmitry V. Levina6809652008-11-10 17:14:58 +0000141static int exit_code = 0;
142static int strace_child = 0;
Denys Vlasenko75422762011-05-27 14:36:01 +0200143static int strace_tracer_pid = 0;
Roland McGratheb9e2e82009-06-02 16:49:22 -0700144
Dmitry V. Levinb9fe0112006-12-13 16:59:44 +0000145static char *username = NULL;
Denys Vlasenkoead73bd2011-06-24 22:49:58 +0200146static uid_t run_uid;
147static gid_t run_gid;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000148
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +0100149unsigned int max_strlen = DEFAULT_STRLEN;
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000150static int acolumn = DEFAULT_ACOLUMN;
Denys Vlasenko102ec492011-08-25 01:27:59 +0200151static char *acolumn_spaces;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100152
Dmitry V. Levinb9fe0112006-12-13 16:59:44 +0000153static char *outfname = NULL;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100154/* If -ff, points to stderr. Else, it's our common output log */
155static FILE *shared_log;
156
Denys Vlasenko000b6012012-01-28 01:25:03 +0100157struct tcb *printing_tcp = NULL;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100158static struct tcb *current_tcp;
159
Denys Vlasenkoead73bd2011-06-24 22:49:58 +0200160static struct tcb **tcbtab;
Denys Vlasenko2b60c352011-06-22 12:45:25 +0200161static unsigned int nprocs, tcbtabsize;
Denys Vlasenkoead73bd2011-06-24 22:49:58 +0200162static const char *progname;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000163
Denys Vlasenkoeec8d5d2013-02-14 03:29:48 +0100164unsigned os_release; /* generated from uname()'s u.release */
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +0100165
Denys Vlasenko4a9ba982013-06-20 11:20:23 +0200166static void detach(struct tcb *tcp);
Andreas Schwabe5355de2009-10-27 16:56:43 +0100167static void cleanup(void);
168static void interrupt(int sig);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000169static sigset_t empty_set, blocked_set;
170
171#ifdef HAVE_SIG_ATOMIC_T
172static volatile sig_atomic_t interrupted;
Denys Vlasenkoa3559252012-01-29 16:43:51 +0100173#else
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000174static volatile int interrupted;
Denys Vlasenkoa3559252012-01-29 16:43:51 +0100175#endif
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000176
Denys Vlasenko2c4fb902012-03-15 17:24:49 +0100177#ifndef HAVE_STRERROR
178
179#if !HAVE_DECL_SYS_ERRLIST
180extern int sys_nerr;
181extern char *sys_errlist[];
Denys Vlasenkoa6d91de2012-03-16 12:02:22 +0100182#endif
Denys Vlasenko2c4fb902012-03-15 17:24:49 +0100183
184const char *
185strerror(int err_no)
186{
187 static char buf[sizeof("Unknown error %d") + sizeof(int)*3];
188
189 if (err_no < 1 || err_no >= sys_nerr) {
190 sprintf(buf, "Unknown error %d", err_no);
191 return buf;
192 }
193 return sys_errlist[err_no];
194}
195
196#endif /* HAVE_STERRROR */
197
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000198static void
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +0300199usage()
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000200{
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +0300201 printf("\
Elvira Khabirova3272d292015-11-26 06:25:12 +0300202usage: strace [-CdffhiqrtttTvVwxxy] [-I n] [-e expr]...\n\
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +0200203 [-a column] [-o file] [-s strsize] [-P path]...\n\
204 -p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]\n\
Elvira Khabirova3272d292015-11-26 06:25:12 +0300205 or: strace -c[dfw] [-I n] [-e expr]... [-O overhead] [-S sortby]\n\
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +0200206 -p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]\n\
Elvira Khabirova3272d292015-11-26 06:25:12 +0300207\n\
208Output format:\n\
209 -a column alignment COLUMN for printing syscall results (default %d)\n\
210 -i print instruction pointer at time of syscall\n\
211 -o file send trace output to FILE instead of stderr\n\
212 -q suppress messages about attaching, detaching, etc.\n\
213 -r print relative timestamp\n\
214 -s strsize limit length of print strings to STRSIZE chars (default %d)\n\
215 -t print absolute timestamp\n\
216 -tt print absolute timestamp with usecs\n\
217 -T print time spent in each syscall\n\
218 -x print non-ascii strings in hex\n\
219 -xx print all strings in hex\n\
220 -y print paths associated with file descriptor arguments\n\
221 -yy print ip:port pairs associated with socket file descriptors\n\
222\n\
223Statistics:\n\
224 -c count time, calls, and errors for each syscall and report summary\n\
225 -C like -c but also print regular output\n\
226 -O overhead set overhead for tracing syscalls to OVERHEAD usecs\n\
227 -S sortby sort syscall counts by: time, calls, name, nothing (default %s)\n\
228 -w summarise syscall latency (default is system time)\n\
229\n\
230Filtering:\n\
231 -e expr a qualifying expression: option=[!]all or option=[!]val1[,val2]...\n\
232 options: trace, abbrev, verbose, raw, signal, read, write\n\
233 -P path trace accesses to path\n\
234\n\
235Tracing:\n\
236 -b execve detach on execve syscall\n\
237 -D run tracer process as a detached grandchild, not as parent\n\
238 -f follow forks\n\
239 -ff follow forks with output into separate files\n\
240 -I interruptible\n\
241 1: no signals are blocked\n\
242 2: fatal signals are blocked while decoding syscall (default)\n\
243 3: fatal signals are always blocked (default if '-o FILE PROG')\n\
244 4: fatal signals and SIGTSTP (^Z) are always blocked\n\
245 (useful to make 'strace -o FILE PROG' not stop on ^Z)\n\
246\n\
247Startup:\n\
248 -E var remove var from the environment for command\n\
249 -E var=val put var=val in the environment for command\n\
250 -p pid trace process with process id PID, may be repeated\n\
251 -u username run command as username handling setuid and/or setgid\n\
252\n\
253Miscellaneous:\n\
254 -d enable debug output to stderr\n\
255 -v verbose mode: print unabbreviated argv, stat, termios, etc. args\n\
256 -h print help message\n\
257 -V print version\n\
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100258"
Luca Clementi327064b2013-07-23 00:11:35 -0700259#ifdef USE_LIBUNWIND
Elvira Khabirova3272d292015-11-26 06:25:12 +0300260" -k obtain stack trace between each syscall (experimental)\n\
Luca Clementi327064b2013-07-23 00:11:35 -0700261"
262#endif
Denys Vlasenko38e79bb2013-02-26 11:33:54 +0100263/* ancient, no one should use it
264-F -- attempt to follow vforks (deprecated, use -f)\n\
265 */
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100266/* this is broken, so don't document it
Michal Ludvig17f8fb32002-11-06 13:17:21 +0000267-z -- print only succeeding syscalls\n\
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100268 */
Roland McGrathde6e5332003-01-24 04:31:23 +0000269, DEFAULT_ACOLUMN, DEFAULT_STRLEN, DEFAULT_SORTBY);
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +0300270 exit(0);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000271}
272
Dmitry V. Levin5647cf82015-03-29 22:45:03 +0000273static void ATTRIBUTE_NORETURN
274die(void)
Denys Vlasenko75422762011-05-27 14:36:01 +0200275{
276 if (strace_tracer_pid == getpid()) {
277 cflag = 0;
278 cleanup();
279 }
280 exit(1);
281}
282
283static void verror_msg(int err_no, const char *fmt, va_list p)
Denys Vlasenko3454e4b2011-05-23 21:29:03 +0200284{
Denys Vlasenko82bb78c2012-01-24 10:17:18 +0100285 char *msg;
286
Dmitry V. Levin44d05322011-06-09 15:50:41 +0000287 fflush(NULL);
Denys Vlasenko82bb78c2012-01-24 10:17:18 +0100288
289 /* We want to print entire message with single fprintf to ensure
290 * message integrity if stderr is shared with other programs.
291 * Thus we use vasprintf + single fprintf.
292 */
293 msg = NULL;
Denys Vlasenkocfad5432012-01-24 12:48:02 +0100294 if (vasprintf(&msg, fmt, p) >= 0) {
Denys Vlasenko82bb78c2012-01-24 10:17:18 +0100295 if (err_no)
296 fprintf(stderr, "%s: %s: %s\n", progname, msg, strerror(err_no));
297 else
298 fprintf(stderr, "%s: %s\n", progname, msg);
299 free(msg);
300 } else {
301 /* malloc in vasprintf failed, try it without malloc */
302 fprintf(stderr, "%s: ", progname);
303 vfprintf(stderr, fmt, p);
304 if (err_no)
305 fprintf(stderr, ": %s\n", strerror(err_no));
306 else
307 putc('\n', stderr);
308 }
309 /* We don't switch stderr to buffered, thus fprintf(stderr)
310 * always flushes its output and this is not necessary: */
311 /* fflush(stderr); */
Denys Vlasenko75422762011-05-27 14:36:01 +0200312}
Denys Vlasenko3454e4b2011-05-23 21:29:03 +0200313
Denys Vlasenko75422762011-05-27 14:36:01 +0200314void error_msg(const char *fmt, ...)
315{
316 va_list p;
317 va_start(p, fmt);
318 verror_msg(0, fmt, p);
319 va_end(p);
320}
321
322void error_msg_and_die(const char *fmt, ...)
323{
324 va_list p;
325 va_start(p, fmt);
326 verror_msg(0, fmt, p);
327 die();
328}
329
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +0300330void error_msg_and_help(const char *fmt, ...)
331{
332 if (fmt != NULL) {
333 va_list p;
334 va_start(p, fmt);
335 verror_msg(0, fmt, p);
336 }
337 fprintf(stderr, "Try '%s -h' for more information.\n", progname);
338 die();
339}
340
Denys Vlasenko75422762011-05-27 14:36:01 +0200341void perror_msg(const char *fmt, ...)
342{
343 va_list p;
344 va_start(p, fmt);
345 verror_msg(errno, fmt, p);
346 va_end(p);
347}
348
349void perror_msg_and_die(const char *fmt, ...)
350{
351 va_list p;
352 va_start(p, fmt);
353 verror_msg(errno, fmt, p);
354 die();
Denys Vlasenko3454e4b2011-05-23 21:29:03 +0200355}
356
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000357static void
358error_opt_arg(int opt, const char *arg)
359{
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +0300360 error_msg_and_help("invalid -%c argument: '%s'", opt, arg);
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000361}
362
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +0100363#if USE_SEIZE
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100364static int
365ptrace_attach_or_seize(int pid)
366{
367 int r;
368 if (!use_seize)
Denys Vlasenkoc169d942013-07-10 14:33:05 +0200369 return ptrace(PTRACE_ATTACH, pid, 0L, 0L);
Dmitry V. Levin23ce9e42015-02-08 13:05:53 +0000370 r = ptrace(PTRACE_SEIZE, pid, 0L, (unsigned long) ptrace_setoptions);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100371 if (r)
372 return r;
Denys Vlasenkoc169d942013-07-10 14:33:05 +0200373 r = ptrace(PTRACE_INTERRUPT, pid, 0L, 0L);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100374 return r;
375}
376#else
377# define ptrace_attach_or_seize(pid) ptrace(PTRACE_ATTACH, (pid), 0, 0)
378#endif
379
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100380/*
381 * Used when we want to unblock stopped traced process.
382 * Should be only used with PTRACE_CONT, PTRACE_DETACH and PTRACE_SYSCALL.
383 * Returns 0 on success or if error was ESRCH
384 * (presumably process was killed while we talk to it).
385 * Otherwise prints error message and returns -1.
386 */
387static int
388ptrace_restart(int op, struct tcb *tcp, int sig)
389{
390 int err;
391 const char *msg;
392
393 errno = 0;
394 ptrace(op, tcp->pid, (void *) 0, (long) sig);
395 err = errno;
Denys Vlasenko23506752012-03-21 10:32:49 +0100396 if (!err)
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100397 return 0;
398
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100399 msg = "SYSCALL";
400 if (op == PTRACE_CONT)
401 msg = "CONT";
402 if (op == PTRACE_DETACH)
403 msg = "DETACH";
404#ifdef PTRACE_LISTEN
405 if (op == PTRACE_LISTEN)
406 msg = "LISTEN";
407#endif
Denys Vlasenko23506752012-03-21 10:32:49 +0100408 /*
409 * Why curcol != 0? Otherwise sometimes we get this:
410 *
411 * 10252 kill(10253, SIGKILL) = 0
412 * <ptrace(SYSCALL,10252):No such process>10253 ...next decode...
413 *
414 * 10252 died after we retrieved syscall exit data,
415 * but before we tried to restart it. Log looks ugly.
416 */
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100417 if (current_tcp && current_tcp->curcol != 0) {
Denys Vlasenko23506752012-03-21 10:32:49 +0100418 tprintf(" <ptrace(%s):%s>\n", msg, strerror(err));
419 line_ended();
420 }
421 if (err == ESRCH)
422 return 0;
423 errno = err;
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100424 perror_msg("ptrace(PTRACE_%s,pid:%d,sig:%d)", msg, tcp->pid, sig);
425 return -1;
426}
427
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200428static void
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000429set_cloexec_flag(int fd)
430{
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200431 int flags, newflags;
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000432
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200433 flags = fcntl(fd, F_GETFD);
434 if (flags < 0) {
435 /* Can happen only if fd is bad.
436 * Should never happen: if it does, we have a bug
437 * in the caller. Therefore we just abort
438 * instead of propagating the error.
439 */
440 perror_msg_and_die("fcntl(%d, F_GETFD)", fd);
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000441 }
442
443 newflags = flags | FD_CLOEXEC;
444 if (flags == newflags)
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200445 return;
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000446
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200447 fcntl(fd, F_SETFD, newflags); /* never fails */
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000448}
449
Denys Vlasenko75fe85c2012-03-09 15:15:24 +0100450static void kill_save_errno(pid_t pid, int sig)
451{
452 int saved_errno = errno;
453
454 (void) kill(pid, sig);
455 errno = saved_errno;
456}
457
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100458/*
459 * When strace is setuid executable, we have to swap uids
460 * before and after filesystem and process management operations.
461 */
462static void
463swap_uid(void)
464{
465 int euid = geteuid(), uid = getuid();
466
467 if (euid != uid && setreuid(euid, uid) < 0) {
468 perror_msg_and_die("setreuid");
469 }
470}
471
Dmitry V. Levin0506f0f2013-11-12 22:34:42 +0000472#ifdef _LARGEFILE64_SOURCE
Dmitry V. Levind3541302014-02-26 00:01:00 +0000473# ifdef HAVE_FOPEN64
474# define fopen_for_output fopen64
475# else
476# define fopen_for_output fopen
477# endif
Dmitry V. Levinc8938e02013-03-20 21:40:15 +0000478# define struct_stat struct stat64
479# define stat_file stat64
480# define struct_dirent struct dirent64
481# define read_dir readdir64
482# define struct_rlimit struct rlimit64
483# define set_rlimit setrlimit64
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100484#else
485# define fopen_for_output fopen
Dmitry V. Levinc8938e02013-03-20 21:40:15 +0000486# define struct_stat struct stat
487# define stat_file stat
488# define struct_dirent struct dirent
489# define read_dir readdir
490# define struct_rlimit struct rlimit
491# define set_rlimit setrlimit
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100492#endif
493
494static FILE *
495strace_fopen(const char *path)
496{
497 FILE *fp;
498
499 swap_uid();
500 fp = fopen_for_output(path, "w");
501 if (!fp)
502 perror_msg_and_die("Can't fopen '%s'", path);
503 swap_uid();
504 set_cloexec_flag(fileno(fp));
505 return fp;
506}
507
508static int popen_pid = 0;
509
510#ifndef _PATH_BSHELL
511# define _PATH_BSHELL "/bin/sh"
512#endif
513
514/*
515 * We cannot use standard popen(3) here because we have to distinguish
516 * popen child process from other processes we trace, and standard popen(3)
517 * does not export its child's pid.
518 */
519static FILE *
520strace_popen(const char *command)
521{
522 FILE *fp;
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200523 int pid;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100524 int fds[2];
525
526 swap_uid();
527 if (pipe(fds) < 0)
528 perror_msg_and_die("pipe");
529
530 set_cloexec_flag(fds[1]); /* never fails */
531
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200532 pid = vfork();
533 if (pid < 0)
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100534 perror_msg_and_die("vfork");
535
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200536 if (pid == 0) {
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100537 /* child */
538 close(fds[1]);
539 if (fds[0] != 0) {
540 if (dup2(fds[0], 0))
541 perror_msg_and_die("dup2");
542 close(fds[0]);
543 }
544 execl(_PATH_BSHELL, "sh", "-c", command, NULL);
545 perror_msg_and_die("Can't execute '%s'", _PATH_BSHELL);
546 }
547
548 /* parent */
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200549 popen_pid = pid;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100550 close(fds[0]);
551 swap_uid();
552 fp = fdopen(fds[1], "w");
553 if (!fp)
554 die_out_of_memory();
555 return fp;
556}
557
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100558void
559tprintf(const char *fmt, ...)
560{
561 va_list args;
562
563 va_start(args, fmt);
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100564 if (current_tcp) {
Denys Vlasenko6e4f3c12012-04-16 18:22:19 +0200565 int n = strace_vfprintf(current_tcp->outf, fmt, args);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100566 if (n < 0) {
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100567 if (current_tcp->outf != stderr)
Dmitry V. Levin9a71bcd2012-09-17 23:20:54 +0000568 perror_msg("%s", outfname);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100569 } else
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100570 current_tcp->curcol += n;
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100571 }
572 va_end(args);
573}
574
Dmitry V. Levind3541302014-02-26 00:01:00 +0000575#ifndef HAVE_FPUTS_UNLOCKED
576# define fputs_unlocked fputs
577#endif
578
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100579void
580tprints(const char *str)
581{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100582 if (current_tcp) {
Denys Vlasenko142aee02012-04-16 18:10:15 +0200583 int n = fputs_unlocked(str, current_tcp->outf);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100584 if (n >= 0) {
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100585 current_tcp->curcol += strlen(str);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100586 return;
587 }
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100588 if (current_tcp->outf != stderr)
Dmitry V. Levin9a71bcd2012-09-17 23:20:54 +0000589 perror_msg("%s", outfname);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100590 }
591}
592
593void
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100594line_ended(void)
595{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100596 if (current_tcp) {
597 current_tcp->curcol = 0;
598 fflush(current_tcp->outf);
599 }
600 if (printing_tcp) {
601 printing_tcp->curcol = 0;
602 printing_tcp = NULL;
603 }
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100604}
605
606void
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100607printleader(struct tcb *tcp)
608{
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100609 /* If -ff, "previous tcb we printed" is always the same as current,
610 * because we have per-tcb output files.
611 */
612 if (followfork >= 2)
613 printing_tcp = tcp;
614
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100615 if (printing_tcp) {
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100616 current_tcp = printing_tcp;
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100617 if (printing_tcp->curcol != 0 && (followfork < 2 || printing_tcp == tcp)) {
618 /*
619 * case 1: we have a shared log (i.e. not -ff), and last line
620 * wasn't finished (same or different tcb, doesn't matter).
621 * case 2: split log, we are the same tcb, but our last line
622 * didn't finish ("SIGKILL nuked us after syscall entry" etc).
623 */
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100624 tprints(" <unfinished ...>\n");
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100625 printing_tcp->curcol = 0;
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100626 }
627 }
628
629 printing_tcp = tcp;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100630 current_tcp = tcp;
631 current_tcp->curcol = 0;
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100632
633 if (print_pid_pfx)
634 tprintf("%-5d ", tcp->pid);
635 else if (nprocs > 1 && !outfname)
636 tprintf("[pid %5u] ", tcp->pid);
637
638 if (tflag) {
639 char str[sizeof("HH:MM:SS")];
640 struct timeval tv, dtv;
641 static struct timeval otv;
642
643 gettimeofday(&tv, NULL);
644 if (rflag) {
645 if (otv.tv_sec == 0)
646 otv = tv;
647 tv_sub(&dtv, &tv, &otv);
648 tprintf("%6ld.%06ld ",
649 (long) dtv.tv_sec, (long) dtv.tv_usec);
650 otv = tv;
651 }
652 else if (tflag > 2) {
653 tprintf("%ld.%06ld ",
654 (long) tv.tv_sec, (long) tv.tv_usec);
655 }
656 else {
657 time_t local = tv.tv_sec;
658 strftime(str, sizeof(str), "%T", localtime(&local));
659 if (tflag > 1)
660 tprintf("%s.%06ld ", str, (long) tv.tv_usec);
661 else
662 tprintf("%s ", str);
663 }
664 }
665 if (iflag)
Denys Vlasenko5a2483b2013-07-01 12:49:14 +0200666 print_pc(tcp);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100667}
668
669void
670tabto(void)
671{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100672 if (current_tcp->curcol < acolumn)
673 tprints(acolumn_spaces + current_tcp->curcol);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100674}
675
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100676/* Should be only called directly *after successful attach* to a tracee.
677 * Otherwise, "strace -oFILE -ff -p<nonexistant_pid>"
678 * may create bogus empty FILE.<nonexistant_pid>, and then die.
679 */
Denys Vlasenko3d5ed412011-06-22 13:17:16 +0200680static void
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000681newoutf(struct tcb *tcp)
682{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100683 tcp->outf = shared_log; /* if not -ff mode, the same file is for all */
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100684 if (followfork >= 2) {
Denys Vlasenko7a8bf062009-01-29 20:38:20 +0000685 char name[520 + sizeof(int) * 3];
Denys Vlasenko7a8bf062009-01-29 20:38:20 +0000686 sprintf(name, "%.512s.%u", outfname, tcp->pid);
Denys Vlasenko3d5ed412011-06-22 13:17:16 +0200687 tcp->outf = strace_fopen(name);
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000688 }
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000689}
690
Denys Vlasenko558e5122012-03-12 23:32:16 +0100691static void
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100692expand_tcbtab(void)
693{
694 /* Allocate some more TCBs and expand the table.
695 We don't want to relocate the TCBs because our
696 callers have pointers and it would be a pain.
697 So tcbtab is a table of pointers. Since we never
698 free the TCBs, we allocate a single chunk of many. */
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +0000699 unsigned int i = tcbtabsize;
Dmitry V. Levin3e9d71f2015-05-25 20:41:02 +0000700 struct tcb *newtcbs = xcalloc(tcbtabsize, sizeof(newtcbs[0]));
701 struct tcb **newtab = xreallocarray(tcbtab, tcbtabsize * 2,
702 sizeof(tcbtab[0]));
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100703 tcbtabsize *= 2;
704 tcbtab = newtab;
705 while (i < tcbtabsize)
706 tcbtab[i++] = newtcbs++;
707}
708
709static struct tcb *
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100710alloctcb(int pid)
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100711{
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +0000712 unsigned int i;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100713 struct tcb *tcp;
714
715 if (nprocs == tcbtabsize)
716 expand_tcbtab();
717
718 for (i = 0; i < tcbtabsize; i++) {
719 tcp = tcbtab[i];
Denys Vlasenkofadbf662013-06-26 14:14:29 +0200720 if (!tcp->pid) {
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100721 memset(tcp, 0, sizeof(*tcp));
722 tcp->pid = pid;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100723#if SUPPORTED_PERSONALITIES > 1
724 tcp->currpers = current_personality;
725#endif
Luca Clementi327064b2013-07-23 00:11:35 -0700726
727#ifdef USE_LIBUNWIND
728 if (stack_trace_enabled)
Masatake YAMATO61413922014-04-16 15:33:02 +0900729 unwind_tcb_init(tcp);
Luca Clementi327064b2013-07-23 00:11:35 -0700730#endif
731
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100732 nprocs++;
733 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +0000734 error_msg("new tcb for pid %d, active tcbs:%d",
735 tcp->pid, nprocs);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100736 return tcp;
737 }
738 }
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100739 error_msg_and_die("bug in alloctcb");
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100740}
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100741
742static void
743droptcb(struct tcb *tcp)
744{
745 if (tcp->pid == 0)
746 return;
747
Masatake YAMATO2b09df92014-04-16 15:33:08 +0900748#ifdef USE_LIBUNWIND
749 if (stack_trace_enabled) {
750 unwind_tcb_fin(tcp);
751 }
752#endif
753
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100754 nprocs--;
755 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +0000756 error_msg("dropped tcb for pid %d, %d remain",
757 tcp->pid, nprocs);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100758
759 if (tcp->outf) {
Denys Vlasenko8511f2a2012-03-22 09:35:51 +0100760 if (followfork >= 2) {
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100761 if (tcp->curcol != 0)
762 fprintf(tcp->outf, " <detached ...>\n");
763 fclose(tcp->outf);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100764 } else {
765 if (printing_tcp == tcp && tcp->curcol != 0)
766 fprintf(tcp->outf, " <detached ...>\n");
767 fflush(tcp->outf);
768 }
769 }
770
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100771 if (current_tcp == tcp)
772 current_tcp = NULL;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100773 if (printing_tcp == tcp)
774 printing_tcp = NULL;
775
776 memset(tcp, 0, sizeof(*tcp));
777}
778
Denys Vlasenkof1669e72013-06-18 18:09:39 +0200779/* Detach traced process.
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100780 * Never call DETACH twice on the same process as both unattached and
781 * attached-unstopped processes give the same ESRCH. For unattached process we
782 * would SIGSTOP it and wait for its SIGSTOP notification forever.
783 */
Denys Vlasenko4a9ba982013-06-20 11:20:23 +0200784static void
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100785detach(struct tcb *tcp)
786{
787 int error;
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200788 int status;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100789
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100790 /*
791 * Linux wrongly insists the child be stopped
792 * before detaching. Arghh. We go through hoops
793 * to make a clean break of things.
794 */
795#if defined(SPARC)
Denys Vlasenko978fbc92012-09-13 10:28:43 +0200796# undef PTRACE_DETACH
797# define PTRACE_DETACH PTRACE_SUNDETACH
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100798#endif
799
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200800 if (!(tcp->flags & TCB_ATTACHED))
801 goto drop;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100802
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200803 /* We attached but possibly didn't see the expected SIGSTOP.
804 * We must catch exactly one as otherwise the detached process
805 * would be left stopped (process state T).
806 */
807 if (tcp->flags & TCB_IGNORE_ONE_SIGSTOP)
808 goto wait_loop;
809
810 error = ptrace(PTRACE_DETACH, tcp->pid, 0, 0);
811 if (!error) {
812 /* On a clear day, you can see forever. */
813 goto drop;
814 }
815 if (errno != ESRCH) {
816 /* Shouldn't happen. */
817 perror_msg("detach: ptrace(PTRACE_DETACH,%u)", tcp->pid);
818 goto drop;
819 }
820 /* ESRCH: process is either not stopped or doesn't exist. */
821 if (my_tkill(tcp->pid, 0) < 0) {
822 if (errno != ESRCH)
823 /* Shouldn't happen. */
824 perror_msg("detach: tkill(%u,0)", tcp->pid);
825 /* else: process doesn't exist. */
826 goto drop;
827 }
828 /* Process is not stopped, need to stop it. */
829 if (use_seize) {
830 /*
831 * With SEIZE, tracee can be in group-stop already.
832 * In this state sending it another SIGSTOP does nothing.
833 * Need to use INTERRUPT.
834 * Testcase: trying to ^C a "strace -p <stopped_process>".
835 */
836 error = ptrace(PTRACE_INTERRUPT, tcp->pid, 0, 0);
837 if (!error)
838 goto wait_loop;
839 if (errno != ESRCH)
840 perror_msg("detach: ptrace(PTRACE_INTERRUPT,%u)", tcp->pid);
841 }
842 else {
843 error = my_tkill(tcp->pid, SIGSTOP);
844 if (!error)
845 goto wait_loop;
846 if (errno != ESRCH)
847 perror_msg("detach: tkill(%u,SIGSTOP)", tcp->pid);
848 }
849 /* Either process doesn't exist, or some weird error. */
850 goto drop;
851
Denys Vlasenkoa2de9da2013-06-21 15:50:41 +0200852 wait_loop:
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200853 /* We end up here in three cases:
854 * 1. We sent PTRACE_INTERRUPT (use_seize case)
855 * 2. We sent SIGSTOP (!use_seize)
856 * 3. Attach SIGSTOP was already pending (TCB_IGNORE_ONE_SIGSTOP set)
857 */
858 for (;;) {
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +0000859 unsigned int sig;
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200860 if (waitpid(tcp->pid, &status, __WALL) < 0) {
861 if (errno == EINTR)
862 continue;
863 /*
864 * if (errno == ECHILD) break;
865 * ^^^ WRONG! We expect this PID to exist,
866 * and want to emit a message otherwise:
867 */
868 perror_msg("detach: waitpid(%u)", tcp->pid);
869 break;
870 }
871 if (!WIFSTOPPED(status)) {
872 /*
873 * Tracee exited or was killed by signal.
874 * We shouldn't normally reach this place:
875 * we don't want to consume exit status.
876 * Consider "strace -p PID" being ^C-ed:
877 * we want merely to detach from PID.
878 *
879 * However, we _can_ end up here if tracee
880 * was SIGKILLed.
881 */
882 break;
883 }
884 sig = WSTOPSIG(status);
885 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +0000886 error_msg("detach wait: event:%d sig:%d",
887 (unsigned)status >> 16, sig);
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200888 if (use_seize) {
889 unsigned event = (unsigned)status >> 16;
890 if (event == PTRACE_EVENT_STOP /*&& sig == SIGTRAP*/) {
Denys Vlasenkofdfa47a2013-06-20 12:10:21 +0200891 /*
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200892 * sig == SIGTRAP: PTRACE_INTERRUPT stop.
893 * sig == other: process was already stopped
894 * with this stopping sig (see tests/detach-stopped).
895 * Looks like re-injecting this sig is not necessary
896 * in DETACH for the tracee to remain stopped.
Denys Vlasenkofdfa47a2013-06-20 12:10:21 +0200897 */
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200898 sig = 0;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100899 }
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200900 /*
901 * PTRACE_INTERRUPT is not guaranteed to produce
902 * the above event if other ptrace-stop is pending.
903 * See tests/detach-sleeping testcase:
904 * strace got SIGINT while tracee is sleeping.
905 * We sent PTRACE_INTERRUPT.
906 * We see syscall exit, not PTRACE_INTERRUPT stop.
907 * We won't get PTRACE_INTERRUPT stop
908 * if we would CONT now. Need to DETACH.
909 */
Denys Vlasenko69e27ef2013-06-19 15:31:39 +0200910 if (sig == syscall_trap_sig)
911 sig = 0;
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200912 /* else: not sure in which case we can be here.
913 * Signal stop? Inject it while detaching.
914 */
915 ptrace_restart(PTRACE_DETACH, tcp, sig);
916 break;
917 }
918 /* Note: this check has to be after use_seize check */
919 /* (else, in use_seize case SIGSTOP will be mistreated) */
920 if (sig == SIGSTOP) {
921 /* Detach, suppressing SIGSTOP */
922 ptrace_restart(PTRACE_DETACH, tcp, 0);
923 break;
924 }
925 if (sig == syscall_trap_sig)
926 sig = 0;
927 /* Can't detach just yet, may need to wait for SIGSTOP */
928 error = ptrace_restart(PTRACE_CONT, tcp, sig);
929 if (error < 0) {
930 /* Should not happen.
931 * Note: ptrace_restart returns 0 on ESRCH, so it's not it.
932 * ptrace_restart already emitted error message.
933 */
934 break;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100935 }
936 }
937
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200938 drop:
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100939 if (!qflag && (tcp->flags & TCB_ATTACHED))
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +0000940 error_msg("Process %u detached", tcp->pid);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100941
942 droptcb(tcp);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100943}
944
945static void
Denys Vlasenko558e5122012-03-12 23:32:16 +0100946process_opt_p_list(char *opt)
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100947{
948 while (*opt) {
949 /*
950 * We accept -p PID,PID; -p "`pidof PROG`"; -p "`pgrep PROG`".
951 * pidof uses space as delim, pgrep uses newline. :(
952 */
953 int pid;
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100954 char *delim = opt + strcspn(opt, ", \n\t");
955 char c = *delim;
956
957 *delim = '\0';
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000958 pid = string_to_uint(opt);
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100959 if (pid <= 0) {
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000960 error_msg_and_die("Invalid process id: '%s'", opt);
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100961 }
962 if (pid == strace_tracer_pid) {
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000963 error_msg_and_die("I'm sorry, I can't let you do that, Dave.");
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100964 }
965 *delim = c;
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100966 alloctcb(pid);
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100967 if (c == '\0')
968 break;
969 opt = delim + 1;
970 }
971}
972
Roland McGrath02203312007-06-11 22:06:31 +0000973static void
974startup_attach(void)
975{
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +0000976 pid_t parent_pid = strace_tracer_pid;
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +0000977 unsigned int tcbi;
Roland McGrath02203312007-06-11 22:06:31 +0000978 struct tcb *tcp;
979
980 /*
981 * Block user interruptions as we would leave the traced
982 * process stopped (process state T) if we would terminate in
Denys Vlasenko2e968c02011-09-01 10:23:09 +0200983 * between PTRACE_ATTACH and wait4() on SIGSTOP.
Denys Vlasenkob63256e2011-06-07 12:13:24 +0200984 * We rely on cleanup() from this point on.
Roland McGrath02203312007-06-11 22:06:31 +0000985 */
986 if (interactive)
987 sigprocmask(SIG_BLOCK, &blocked_set, NULL);
988
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000989 if (daemonized_tracer) {
990 pid_t pid = fork();
991 if (pid < 0) {
Denys Vlasenko014ca3a2011-09-02 16:19:30 +0200992 perror_msg_and_die("fork");
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000993 }
994 if (pid) { /* parent */
995 /*
Denys Vlasenko75422762011-05-27 14:36:01 +0200996 * Wait for grandchild to attach to straced process
997 * (grandparent). Grandchild SIGKILLs us after it attached.
998 * Grandparent's wait() is unblocked by our death,
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000999 * it proceeds to exec the straced program.
1000 */
1001 pause();
1002 _exit(0); /* paranoia */
1003 }
Denys Vlasenko75422762011-05-27 14:36:01 +02001004 /* grandchild */
1005 /* We will be the tracer process. Remember our new pid: */
1006 strace_tracer_pid = getpid();
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001007 }
1008
Roland McGrath02203312007-06-11 22:06:31 +00001009 for (tcbi = 0; tcbi < tcbtabsize; tcbi++) {
1010 tcp = tcbtab[tcbi];
Denys Vlasenko44f87ef2011-08-17 15:18:21 +02001011
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001012 if (!tcp->pid)
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001013 continue;
1014
Denys Vlasenkod116a732011-09-05 14:01:33 +02001015 /* Is this a process we should attach to, but not yet attached? */
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001016 if (tcp->flags & TCB_ATTACHED)
1017 continue; /* no, we already attached it */
Denys Vlasenkod116a732011-09-05 14:01:33 +02001018
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001019 if (tcp->pid == parent_pid || tcp->pid == strace_tracer_pid) {
1020 errno = EPERM;
1021 perror_msg("attach: %d", tcp->pid);
1022 droptcb(tcp);
1023 continue;
1024 }
1025 if (followfork && tcp->pid != strace_child) {
Denys Vlasenko7a8bf062009-01-29 20:38:20 +00001026 char procdir[sizeof("/proc/%d/task") + sizeof(int) * 3];
Roland McGrath02203312007-06-11 22:06:31 +00001027 DIR *dir;
1028
1029 sprintf(procdir, "/proc/%d/task", tcp->pid);
1030 dir = opendir(procdir);
1031 if (dir != NULL) {
1032 unsigned int ntid = 0, nerr = 0;
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001033 struct_dirent *de;
Denys Vlasenko381dbc22011-09-05 13:59:39 +02001034
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001035 while ((de = read_dir(dir)) != NULL) {
Denys Vlasenko381dbc22011-09-05 13:59:39 +02001036 struct tcb *cur_tcp;
1037 int tid;
1038
Denys Vlasenko7a8bf062009-01-29 20:38:20 +00001039 if (de->d_fileno == 0)
Roland McGrath02203312007-06-11 22:06:31 +00001040 continue;
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001041 /* we trust /proc filesystem */
Roland McGrath02203312007-06-11 22:06:31 +00001042 tid = atoi(de->d_name);
1043 if (tid <= 0)
1044 continue;
1045 ++ntid;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001046 if (ptrace_attach_or_seize(tid) < 0) {
Roland McGrath02203312007-06-11 22:06:31 +00001047 ++nerr;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001048 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001049 error_msg("attach to pid %d failed", tid);
Denys Vlasenko381dbc22011-09-05 13:59:39 +02001050 continue;
Denys Vlasenkof95397a2011-06-24 16:51:16 +02001051 }
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001052 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001053 error_msg("attach to pid %d succeeded", tid);
Denys Vlasenko381dbc22011-09-05 13:59:39 +02001054 cur_tcp = tcp;
1055 if (tid != tcp->pid)
1056 cur_tcp = alloctcb(tid);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001057 cur_tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001058 newoutf(cur_tcp);
Roland McGrath02203312007-06-11 22:06:31 +00001059 }
1060 closedir(dir);
Denys Vlasenko381dbc22011-09-05 13:59:39 +02001061 if (interactive) {
1062 sigprocmask(SIG_SETMASK, &empty_set, NULL);
1063 if (interrupted)
1064 goto ret;
1065 sigprocmask(SIG_BLOCK, &blocked_set, NULL);
1066 }
Denys Vlasenko7a8bf062009-01-29 20:38:20 +00001067 ntid -= nerr;
1068 if (ntid == 0) {
Denys Vlasenko905e8e02013-02-26 12:30:09 +01001069 perror_msg("attach: ptrace(PTRACE_ATTACH, ...)");
Roland McGrath02203312007-06-11 22:06:31 +00001070 droptcb(tcp);
1071 continue;
1072 }
1073 if (!qflag) {
Dmitry V. Levinbb746ff2015-11-26 01:54:53 +00001074 if (ntid > 1)
1075 error_msg("Process %u attached"
1076 " with %u threads",
1077 tcp->pid, ntid);
1078 else
1079 error_msg("Process %u attached",
1080 tcp->pid);
Roland McGrath02203312007-06-11 22:06:31 +00001081 }
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001082 if (!(tcp->flags & TCB_ATTACHED)) {
Denys Vlasenkof88837a2011-09-05 14:05:46 +02001083 /* -p PID, we failed to attach to PID itself
1084 * but did attach to some of its sibling threads.
1085 * Drop PID's tcp.
1086 */
1087 droptcb(tcp);
1088 }
Roland McGrath02203312007-06-11 22:06:31 +00001089 continue;
Denys Vlasenko7a8bf062009-01-29 20:38:20 +00001090 } /* if (opendir worked) */
1091 } /* if (-f) */
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001092 if (ptrace_attach_or_seize(tcp->pid) < 0) {
Denys Vlasenko905e8e02013-02-26 12:30:09 +01001093 perror_msg("attach: ptrace(PTRACE_ATTACH, ...)");
Roland McGrath02203312007-06-11 22:06:31 +00001094 droptcb(tcp);
1095 continue;
1096 }
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001097 tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001098 newoutf(tcp);
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001099 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001100 error_msg("attach to pid %d (main) succeeded", tcp->pid);
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001101
Roland McGrath02203312007-06-11 22:06:31 +00001102 if (!qflag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001103 error_msg("Process %u attached", tcp->pid);
Denys Vlasenkof95397a2011-06-24 16:51:16 +02001104 } /* for each tcbtab[] */
Roland McGrath02203312007-06-11 22:06:31 +00001105
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001106 if (daemonized_tracer) {
1107 /*
1108 * Make parent go away.
1109 * Also makes grandparent's wait() unblock.
1110 */
1111 kill(parent_pid, SIGKILL);
1112 strace_child = 0;
1113 }
1114
Denys Vlasenko44f87ef2011-08-17 15:18:21 +02001115 ret:
Roland McGrath02203312007-06-11 22:06:31 +00001116 if (interactive)
1117 sigprocmask(SIG_SETMASK, &empty_set, NULL);
1118}
1119
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001120/* Stack-o-phobic exec helper, in the hope to work around
1121 * NOMMU + "daemonized tracer" difficulty.
1122 */
1123struct exec_params {
1124 int fd_to_close;
1125 uid_t run_euid;
1126 gid_t run_egid;
1127 char **argv;
1128 char *pathname;
1129};
1130static struct exec_params params_for_tracee;
Dmitry V. Levin5647cf82015-03-29 22:45:03 +00001131
1132static void ATTRIBUTE_NOINLINE ATTRIBUTE_NORETURN
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001133exec_or_die(void)
1134{
1135 struct exec_params *params = &params_for_tracee;
1136
1137 if (params->fd_to_close >= 0)
1138 close(params->fd_to_close);
1139 if (!daemonized_tracer && !use_seize) {
1140 if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) < 0) {
1141 perror_msg_and_die("ptrace(PTRACE_TRACEME, ...)");
1142 }
1143 }
1144
1145 if (username != NULL) {
1146 /*
1147 * It is important to set groups before we
1148 * lose privileges on setuid.
1149 */
1150 if (initgroups(username, run_gid) < 0) {
1151 perror_msg_and_die("initgroups");
1152 }
1153 if (setregid(run_gid, params->run_egid) < 0) {
1154 perror_msg_and_die("setregid");
1155 }
1156 if (setreuid(run_uid, params->run_euid) < 0) {
1157 perror_msg_and_die("setreuid");
1158 }
1159 }
1160 else if (geteuid() != 0)
1161 if (setreuid(run_uid, run_uid) < 0) {
1162 perror_msg_and_die("setreuid");
1163 }
1164
1165 if (!daemonized_tracer) {
1166 /*
1167 * Induce a ptrace stop. Tracer (our parent)
1168 * will resume us with PTRACE_SYSCALL and display
1169 * the immediately following execve syscall.
1170 * Can't do this on NOMMU systems, we are after
1171 * vfork: parent is blocked, stopping would deadlock.
1172 */
1173 if (!NOMMU_SYSTEM)
1174 kill(getpid(), SIGSTOP);
1175 } else {
1176 alarm(3);
1177 /* we depend on SIGCHLD set to SIG_DFL by init code */
1178 /* if it happens to be SIG_IGN'ed, wait won't block */
1179 wait(NULL);
1180 alarm(0);
1181 }
1182
1183 execv(params->pathname, params->argv);
1184 perror_msg_and_die("exec");
1185}
1186
Roland McGrath02203312007-06-11 22:06:31 +00001187static void
Denys Vlasenko12014262011-05-30 14:00:14 +02001188startup_child(char **argv)
Roland McGrath02203312007-06-11 22:06:31 +00001189{
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001190 struct_stat statbuf;
Roland McGrath02203312007-06-11 22:06:31 +00001191 const char *filename;
Dmitry V. Levin1dbd39e2015-02-28 14:50:09 +00001192 size_t filename_len;
Dmitry V. Levin025b3582014-11-21 22:28:34 +00001193 char pathname[PATH_MAX];
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001194 int pid;
Roland McGrath02203312007-06-11 22:06:31 +00001195 struct tcb *tcp;
1196
1197 filename = argv[0];
Dmitry V. Levin1dbd39e2015-02-28 14:50:09 +00001198 filename_len = strlen(filename);
1199
1200 if (filename_len > sizeof(pathname) - 1) {
1201 errno = ENAMETOOLONG;
1202 perror_msg_and_die("exec");
1203 }
Roland McGrath02203312007-06-11 22:06:31 +00001204 if (strchr(filename, '/')) {
Roland McGrath02203312007-06-11 22:06:31 +00001205 strcpy(pathname, filename);
1206 }
1207#ifdef USE_DEBUGGING_EXEC
1208 /*
1209 * Debuggers customarily check the current directory
1210 * first regardless of the path but doing that gives
1211 * security geeks a panic attack.
1212 */
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001213 else if (stat_file(filename, &statbuf) == 0)
Roland McGrath02203312007-06-11 22:06:31 +00001214 strcpy(pathname, filename);
1215#endif /* USE_DEBUGGING_EXEC */
1216 else {
Dmitry V. Levin30145dd2010-09-06 22:08:24 +00001217 const char *path;
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +00001218 size_t m, n, len;
Roland McGrath02203312007-06-11 22:06:31 +00001219
1220 for (path = getenv("PATH"); path && *path; path += m) {
Denys Vlasenko4f3df072012-01-29 22:38:35 +01001221 const char *colon = strchr(path, ':');
1222 if (colon) {
1223 n = colon - path;
Roland McGrath02203312007-06-11 22:06:31 +00001224 m = n + 1;
1225 }
1226 else
1227 m = n = strlen(path);
1228 if (n == 0) {
Dmitry V. Levin025b3582014-11-21 22:28:34 +00001229 if (!getcwd(pathname, PATH_MAX))
Roland McGrath02203312007-06-11 22:06:31 +00001230 continue;
1231 len = strlen(pathname);
1232 }
1233 else if (n > sizeof pathname - 1)
1234 continue;
1235 else {
1236 strncpy(pathname, path, n);
1237 len = n;
1238 }
1239 if (len && pathname[len - 1] != '/')
1240 pathname[len++] = '/';
Dmitry V. Levin1dbd39e2015-02-28 14:50:09 +00001241 if (filename_len + len > sizeof(pathname) - 1)
1242 continue;
Roland McGrath02203312007-06-11 22:06:31 +00001243 strcpy(pathname + len, filename);
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001244 if (stat_file(pathname, &statbuf) == 0 &&
Roland McGrath02203312007-06-11 22:06:31 +00001245 /* Accept only regular files
1246 with some execute bits set.
1247 XXX not perfect, might still fail */
1248 S_ISREG(statbuf.st_mode) &&
1249 (statbuf.st_mode & 0111))
1250 break;
1251 }
Dmitry V. Levin1dbd39e2015-02-28 14:50:09 +00001252 if (!path || !*path)
1253 pathname[0] = '\0';
Roland McGrath02203312007-06-11 22:06:31 +00001254 }
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001255 if (stat_file(pathname, &statbuf) < 0) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001256 perror_msg_and_die("Can't stat '%s'", filename);
Roland McGrath02203312007-06-11 22:06:31 +00001257 }
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001258
1259 params_for_tracee.fd_to_close = (shared_log != stderr) ? fileno(shared_log) : -1;
1260 params_for_tracee.run_euid = (statbuf.st_mode & S_ISUID) ? statbuf.st_uid : run_uid;
1261 params_for_tracee.run_egid = (statbuf.st_mode & S_ISGID) ? statbuf.st_gid : run_gid;
1262 params_for_tracee.argv = argv;
1263 /*
1264 * On NOMMU, can be safely freed only after execve in tracee.
1265 * It's hard to know when that happens, so we just leak it.
1266 */
Dmitry V. Levin3e9d71f2015-05-25 20:41:02 +00001267 params_for_tracee.pathname = NOMMU_SYSTEM ? xstrdup(pathname) : pathname;
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001268
Dmitry V. Levin882478a2013-05-13 18:43:28 +00001269#if defined HAVE_PRCTL && defined PR_SET_PTRACER && defined PR_SET_PTRACER_ANY
1270 if (daemonized_tracer)
1271 prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY);
1272#endif
1273
Denys Vlasenkoe8681c92013-06-26 14:27:11 +02001274 pid = fork();
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001275 if (pid < 0) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001276 perror_msg_and_die("fork");
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001277 }
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001278 if ((pid != 0 && daemonized_tracer)
1279 || (pid == 0 && !daemonized_tracer)
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001280 ) {
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001281 /* We are to become the tracee. Two cases:
1282 * -D: we are parent
1283 * not -D: we are child
1284 */
1285 exec_or_die();
Roland McGrath02203312007-06-11 22:06:31 +00001286 }
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001287
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001288 /* We are the tracer */
Denys Vlasenko75422762011-05-27 14:36:01 +02001289
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001290 if (!daemonized_tracer) {
Denys Vlasenkoe8681c92013-06-26 14:27:11 +02001291 strace_child = pid;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001292 if (!use_seize) {
1293 /* child did PTRACE_TRACEME, nothing to do in parent */
1294 } else {
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001295 if (!NOMMU_SYSTEM) {
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001296 /* Wait until child stopped itself */
1297 int status;
1298 while (waitpid(pid, &status, WSTOPPED) < 0) {
1299 if (errno == EINTR)
1300 continue;
1301 perror_msg_and_die("waitpid");
1302 }
1303 if (!WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP) {
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001304 kill_save_errno(pid, SIGKILL);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001305 perror_msg_and_die("Unexpected wait status %x", status);
1306 }
1307 }
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001308 /* Else: NOMMU case, we have no way to sync.
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001309 * Just attach to it as soon as possible.
1310 * This means that we may miss a few first syscalls...
1311 */
1312
1313 if (ptrace_attach_or_seize(pid)) {
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001314 kill_save_errno(pid, SIGKILL);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001315 perror_msg_and_die("Can't attach to %d", pid);
1316 }
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001317 if (!NOMMU_SYSTEM)
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001318 kill(pid, SIGCONT);
1319 }
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001320 tcp = alloctcb(pid);
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001321 if (!NOMMU_SYSTEM)
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001322 tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
Denys Vlasenkof88837a2011-09-05 14:05:46 +02001323 else
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001324 tcp->flags |= TCB_ATTACHED | TCB_STARTUP;
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001325 newoutf(tcp);
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001326 }
1327 else {
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001328 /* With -D, we are *child* here, the tracee is our parent. */
1329 strace_child = strace_tracer_pid;
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001330 strace_tracer_pid = getpid();
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001331 alloctcb(strace_child);
Denys Vlasenkof2025022012-03-09 15:29:45 +01001332 /* attaching will be done later, by startup_attach */
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001333 /* note: we don't do newoutf(tcp) here either! */
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001334
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001335 /* NOMMU BUG! -D mode is active, we (child) return,
1336 * and we will scribble over parent's stack!
1337 * When parent later unpauses, it segfaults.
1338 *
1339 * We work around it
1340 * (1) by declaring exec_or_die() NORETURN,
1341 * hopefully compiler will just jump to it
1342 * instead of call (won't push anything to stack),
1343 * (2) by trying very hard in exec_or_die()
1344 * to not use any stack,
Dmitry V. Levin025b3582014-11-21 22:28:34 +00001345 * (3) having a really big (PATH_MAX) stack object
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001346 * in this function, which creates a "buffer" between
1347 * child's and parent's stack pointers.
1348 * This may save us if (1) and (2) failed
1349 * and compiler decided to use stack in exec_or_die() anyway
1350 * (happens on i386 because of stack parameter passing).
Denys Vlasenko05f32512013-02-26 12:00:34 +01001351 *
1352 * A cleaner solution is to use makecontext + setcontext
1353 * to create a genuine separate stack and execute on it.
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001354 */
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001355 }
Roland McGrath02203312007-06-11 22:06:31 +00001356}
1357
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001358#if USE_SEIZE
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001359static void
1360test_ptrace_seize(void)
1361{
1362 int pid;
1363
Denys Vlasenko05f32512013-02-26 12:00:34 +01001364 /* Need fork for test. NOMMU has no forks */
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001365 if (NOMMU_SYSTEM) {
1366 post_attach_sigstop = 0; /* this sets use_seize to 1 */
1367 return;
1368 }
1369
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001370 pid = fork();
1371 if (pid < 0)
1372 perror_msg_and_die("fork");
1373
1374 if (pid == 0) {
1375 pause();
1376 _exit(0);
1377 }
1378
1379 /* PTRACE_SEIZE, unlike ATTACH, doesn't force tracee to trap. After
1380 * attaching tracee continues to run unless a trap condition occurs.
1381 * PTRACE_SEIZE doesn't affect signal or group stop state.
1382 */
Denys Vlasenko26bc0602012-07-10 16:36:32 +02001383 if (ptrace(PTRACE_SEIZE, pid, 0, 0) == 0) {
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001384 post_attach_sigstop = 0; /* this sets use_seize to 1 */
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001385 } else if (debug_flag) {
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001386 error_msg("PTRACE_SEIZE doesn't work");
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001387 }
1388
1389 kill(pid, SIGKILL);
1390
1391 while (1) {
1392 int status, tracee_pid;
1393
1394 errno = 0;
1395 tracee_pid = waitpid(pid, &status, 0);
1396 if (tracee_pid <= 0) {
1397 if (errno == EINTR)
1398 continue;
1399 perror_msg_and_die("%s: unexpected wait result %d",
1400 __func__, tracee_pid);
1401 }
1402 if (WIFSIGNALED(status)) {
1403 return;
1404 }
1405 error_msg_and_die("%s: unexpected wait status %x",
1406 __func__, status);
1407 }
1408}
Denys Vlasenko978fbc92012-09-13 10:28:43 +02001409#else /* !USE_SEIZE */
1410# define test_ptrace_seize() ((void)0)
1411#endif
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001412
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001413static unsigned
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001414get_os_release(void)
1415{
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001416 unsigned rel;
1417 const char *p;
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001418 struct utsname u;
1419 if (uname(&u) < 0)
1420 perror_msg_and_die("uname");
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001421 /* u.release has this form: "3.2.9[-some-garbage]" */
1422 rel = 0;
1423 p = u.release;
1424 for (;;) {
1425 if (!(*p >= '0' && *p <= '9'))
1426 error_msg_and_die("Bad OS release string: '%s'", u.release);
1427 /* Note: this open-codes KERNEL_VERSION(): */
1428 rel = (rel << 8) | atoi(p);
1429 if (rel >= KERNEL_VERSION(1,0,0))
1430 break;
1431 while (*p >= '0' && *p <= '9')
1432 p++;
Dmitry V. Levin0dbc80d2012-05-14 23:42:10 +00001433 if (*p != '.') {
1434 if (rel >= KERNEL_VERSION(0,1,0)) {
1435 /* "X.Y-something" means "X.Y.0" */
1436 rel <<= 8;
1437 break;
1438 }
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001439 error_msg_and_die("Bad OS release string: '%s'", u.release);
Dmitry V. Levin0dbc80d2012-05-14 23:42:10 +00001440 }
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001441 p++;
1442 }
1443 return rel;
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001444}
1445
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01001446/*
1447 * Initialization part of main() was eating much stack (~0.5k),
1448 * which was unused after init.
1449 * We can reuse it if we move init code into a separate function.
1450 *
1451 * Don't want main() to inline us and defeat the reason
1452 * we have a separate function.
1453 */
Dmitry V. Levin5647cf82015-03-29 22:45:03 +00001454static void ATTRIBUTE_NOINLINE
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01001455init(int argc, char *argv[])
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001456{
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001457 struct tcb *tcp;
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001458 int c, i;
Dmitry V. Levin06350db2008-07-25 15:42:34 +00001459 int optF = 0;
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +00001460 unsigned int tcbi;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001461 struct sigaction sa;
1462
Dmitry V. Levin08b623e2007-10-08 21:04:41 +00001463 progname = argv[0] ? argv[0] : "strace";
1464
Denys Vlasenkoa5090542012-03-15 17:27:49 +01001465 /* Make sure SIGCHLD has the default action so that waitpid
1466 definitely works without losing track of children. The user
1467 should not have given us a bogus state to inherit, but he might
1468 have. Arguably we should detect SIG_IGN here and pass it on
1469 to children, but probably noone really needs that. */
1470 signal(SIGCHLD, SIG_DFL);
1471
Denys Vlasenko75422762011-05-27 14:36:01 +02001472 strace_tracer_pid = getpid();
1473
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001474 os_release = get_os_release();
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001475
Roland McGrathee9d4352002-12-18 04:16:10 +00001476 /* Allocate the initial tcbtab. */
1477 tcbtabsize = argc; /* Surely enough for all -p args. */
Dmitry V. Levin3e9d71f2015-05-25 20:41:02 +00001478 tcbtab = xcalloc(tcbtabsize, sizeof(tcbtab[0]));
1479 tcp = xcalloc(tcbtabsize, sizeof(*tcp));
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +00001480 for (tcbi = 0; tcbi < tcbtabsize; tcbi++)
1481 tcbtab[tcbi] = tcp++;
Roland McGrathee9d4352002-12-18 04:16:10 +00001482
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001483 shared_log = stderr;
Roland McGrath138c6a32006-01-12 09:50:49 +00001484 set_sortby(DEFAULT_SORTBY);
1485 set_personality(DEFAULT_PERSONALITY);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001486 qualify("trace=all");
1487 qualify("abbrev=all");
1488 qualify("verbose=all");
Denys Vlasenko74ec14f2013-02-21 16:13:47 +01001489#if DEFAULT_QUAL_FLAGS != (QUAL_TRACE | QUAL_ABBREV | QUAL_VERBOSE)
1490# error Bug in DEFAULT_QUAL_FLAGS
1491#endif
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001492 qualify("signal=all");
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001493 while ((c = getopt(argc, argv,
Mark Hillse53bf232014-05-28 17:52:40 +01001494 "+b:cCdfFhiqrtTvVwxyz"
Luca Clementi327064b2013-07-23 00:11:35 -07001495#ifdef USE_LIBUNWIND
1496 "k"
1497#endif
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001498 "D"
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001499 "a:e:o:O:p:s:S:u:E:P:I:")) != EOF) {
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001500 switch (c) {
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001501 case 'b':
Denys Vlasenko22efaf02013-02-27 12:15:19 +01001502 if (strcmp(optarg, "execve") != 0)
1503 error_msg_and_die("Syscall '%s' for -b isn't supported",
1504 optarg);
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001505 detach_on_execve = 1;
1506 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001507 case 'c':
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00001508 if (cflag == CFLAG_BOTH) {
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001509 error_msg_and_help("-c and -C are mutually exclusive");
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00001510 }
1511 cflag = CFLAG_ONLY_STATS;
1512 break;
1513 case 'C':
1514 if (cflag == CFLAG_ONLY_STATS) {
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001515 error_msg_and_help("-c and -C are mutually exclusive");
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00001516 }
1517 cflag = CFLAG_BOTH;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001518 break;
1519 case 'd':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001520 debug_flag = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001521 break;
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001522 case 'D':
1523 daemonized_tracer = 1;
1524 break;
Roland McGrath41c48222008-07-18 00:25:10 +00001525 case 'F':
Dmitry V. Levin06350db2008-07-25 15:42:34 +00001526 optF = 1;
1527 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001528 case 'f':
1529 followfork++;
1530 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001531 case 'h':
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001532 usage();
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001533 break;
1534 case 'i':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001535 iflag = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001536 break;
1537 case 'q':
Daniel P. Berrange01997cf2013-05-13 11:30:55 +01001538 qflag++;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001539 break;
1540 case 'r':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001541 rflag = 1;
1542 /* fall through to tflag++ */
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001543 case 't':
1544 tflag++;
1545 break;
1546 case 'T':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001547 Tflag = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001548 break;
Mark Hillse53bf232014-05-28 17:52:40 +01001549 case 'w':
1550 count_wallclock = 1;
1551 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001552 case 'x':
1553 xflag++;
1554 break;
Grant Edwards8a082772011-04-07 20:25:40 +00001555 case 'y':
Dmitry V. Levin45e7b182014-08-08 23:38:26 +00001556 show_fd_path++;
Grant Edwards8a082772011-04-07 20:25:40 +00001557 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001558 case 'v':
1559 qualify("abbrev=none");
1560 break;
1561 case 'V':
Roland McGrath9c9a2532003-02-20 02:56:29 +00001562 printf("%s -- version %s\n", PACKAGE_NAME, VERSION);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001563 exit(0);
1564 break;
Michal Ludvig17f8fb32002-11-06 13:17:21 +00001565 case 'z':
1566 not_failing_only = 1;
1567 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001568 case 'a':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001569 acolumn = string_to_uint(optarg);
Denys Vlasenko102ec492011-08-25 01:27:59 +02001570 if (acolumn < 0)
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001571 error_opt_arg(c, optarg);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001572 break;
1573 case 'e':
1574 qualify(optarg);
1575 break;
1576 case 'o':
Dmitry V. Levin3e9d71f2015-05-25 20:41:02 +00001577 outfname = xstrdup(optarg);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001578 break;
1579 case 'O':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001580 i = string_to_uint(optarg);
1581 if (i < 0)
1582 error_opt_arg(c, optarg);
1583 set_overhead(i);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001584 break;
1585 case 'p':
Denys Vlasenkoe8172b72012-03-09 13:01:04 +01001586 process_opt_p_list(optarg);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001587 break;
Grant Edwards8a082772011-04-07 20:25:40 +00001588 case 'P':
Denys Vlasenko7239dbc2013-03-05 15:46:34 +01001589 pathtrace_select(optarg);
Grant Edwards8a082772011-04-07 20:25:40 +00001590 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001591 case 's':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001592 i = string_to_uint(optarg);
1593 if (i < 0)
1594 error_opt_arg(c, optarg);
1595 max_strlen = i;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001596 break;
1597 case 'S':
1598 set_sortby(optarg);
1599 break;
1600 case 'u':
Dmitry V. Levin3e9d71f2015-05-25 20:41:02 +00001601 username = xstrdup(optarg);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001602 break;
Luca Clementi327064b2013-07-23 00:11:35 -07001603#ifdef USE_LIBUNWIND
1604 case 'k':
1605 stack_trace_enabled = true;
1606 break;
1607#endif
Roland McGrathde6e5332003-01-24 04:31:23 +00001608 case 'E':
Denys Vlasenko1d46ba52011-08-31 14:00:02 +02001609 if (putenv(optarg) < 0)
1610 die_out_of_memory();
Roland McGrathde6e5332003-01-24 04:31:23 +00001611 break;
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001612 case 'I':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001613 opt_intr = string_to_uint(optarg);
1614 if (opt_intr <= 0 || opt_intr >= NUM_INTR_OPTS)
1615 error_opt_arg(c, optarg);
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001616 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001617 default:
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001618 error_msg_and_help(NULL);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001619 break;
1620 }
1621 }
Denys Vlasenko837399a2012-01-24 11:37:03 +01001622 argv += optind;
1623 /* argc -= optind; - no need, argc is not used below */
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001624
Dmitry V. Levin3e9d71f2015-05-25 20:41:02 +00001625 acolumn_spaces = xmalloc(acolumn + 1);
Denys Vlasenko102ec492011-08-25 01:27:59 +02001626 memset(acolumn_spaces, ' ', acolumn);
1627 acolumn_spaces[acolumn] = '\0';
1628
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001629 if (!argv[0] && !nprocs) {
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001630 error_msg_and_help("must have PROG [ARGS] or -p PID");
1631 }
Roland McGrathce0d1542003-11-11 21:24:23 +00001632
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001633 if (!argv[0] && daemonized_tracer) {
1634 error_msg_and_help("PROG [ARGS] must be specified with -D");
Wang Chaod322a4b2010-08-05 14:30:11 +08001635 }
1636
Dmitry V. Levin06350db2008-07-25 15:42:34 +00001637 if (!followfork)
1638 followfork = optF;
1639
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001640 if (followfork >= 2 && cflag) {
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001641 error_msg_and_help("(-c or -C) and -ff are mutually exclusive");
Roland McGrathcb9def62006-04-25 07:48:03 +00001642 }
1643
Mark Hillse53bf232014-05-28 17:52:40 +01001644 if (count_wallclock && !cflag) {
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001645 error_msg_and_help("-w must be given with (-c or -C)");
Mark Hillse53bf232014-05-28 17:52:40 +01001646 }
1647
Dmitry V. Levin2727aae2014-06-03 13:20:05 +00001648 if (cflag == CFLAG_ONLY_STATS) {
1649 if (iflag)
1650 error_msg("-%c has no effect with -c", 'i');
1651#ifdef USE_LIBUNWIND
1652 if (stack_trace_enabled)
1653 error_msg("-%c has no effect with -c", 'k');
1654#endif
1655 if (rflag)
1656 error_msg("-%c has no effect with -c", 'r');
1657 if (tflag)
1658 error_msg("-%c has no effect with -c", 't');
1659 if (Tflag)
1660 error_msg("-%c has no effect with -c", 'T');
1661 if (show_fd_path)
1662 error_msg("-%c has no effect with -c", 'y');
1663 }
1664
1665#ifdef USE_LIBUNWIND
1666 if (stack_trace_enabled)
1667 unwind_init();
1668#endif
1669
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001670 /* See if they want to run as another user. */
1671 if (username != NULL) {
1672 struct passwd *pent;
1673
1674 if (getuid() != 0 || geteuid() != 0) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001675 error_msg_and_die("You must be root to use the -u option");
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001676 }
Denys Vlasenko5d645812011-08-20 12:48:18 +02001677 pent = getpwnam(username);
1678 if (pent == NULL) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001679 error_msg_and_die("Cannot find user '%s'", username);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001680 }
1681 run_uid = pent->pw_uid;
1682 run_gid = pent->pw_gid;
1683 }
1684 else {
1685 run_uid = getuid();
1686 run_gid = getgid();
1687 }
1688
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001689 if (followfork)
Dmitry V. Levin23ce9e42015-02-08 13:05:53 +00001690 ptrace_setoptions |= PTRACE_O_TRACECLONE |
1691 PTRACE_O_TRACEFORK |
1692 PTRACE_O_TRACEVFORK;
1693 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001694 error_msg("ptrace_setoptions = %#x", ptrace_setoptions);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001695 test_ptrace_seize();
Dmitry V. Levin8044bc12010-12-07 12:50:49 +00001696
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001697 /* Check if they want to redirect the output. */
1698 if (outfname) {
Roland McGrath37b9a662003-11-07 02:26:54 +00001699 /* See if they want to pipe the output. */
1700 if (outfname[0] == '|' || outfname[0] == '!') {
1701 /*
1702 * We can't do the <outfname>.PID funny business
1703 * when using popen, so prohibit it.
1704 */
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001705 if (followfork >= 2)
Elvira Khabirovaa2fdfe92015-11-26 17:18:00 +03001706 error_msg_and_help("piping the output and -ff are mutually exclusive");
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001707 shared_log = strace_popen(outfname + 1);
Roland McGrath37b9a662003-11-07 02:26:54 +00001708 }
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001709 else if (followfork < 2)
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001710 shared_log = strace_fopen(outfname);
Denys Vlasenko328bf252012-03-12 23:34:13 +01001711 } else {
1712 /* -ff without -o FILE is the same as single -f */
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001713 if (followfork >= 2)
Denys Vlasenko328bf252012-03-12 23:34:13 +01001714 followfork = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001715 }
1716
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001717 if (!outfname || outfname[0] == '|' || outfname[0] == '!') {
Dmitry V. Levin3e9d71f2015-05-25 20:41:02 +00001718 char *buf = xmalloc(BUFSIZ);
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001719 setvbuf(shared_log, buf, _IOLBF, BUFSIZ);
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001720 }
Denys Vlasenko837399a2012-01-24 11:37:03 +01001721 if (outfname && argv[0]) {
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001722 if (!opt_intr)
1723 opt_intr = INTR_NEVER;
Dmitry V. Levinde4a6802015-06-29 14:37:26 +00001724 if (!qflag)
1725 qflag = 1;
Roland McGrath36931052003-06-03 01:35:20 +00001726 }
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001727 if (!opt_intr)
1728 opt_intr = INTR_WHILE_WAIT;
Wang Chaob13c0de2010-11-12 17:25:19 +08001729
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001730 /* argv[0] -pPID -oFILE Default interactive setting
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001731 * yes * 0 INTR_WHILE_WAIT
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001732 * no 1 0 INTR_WHILE_WAIT
Dmitry V. Levinfa8c2862016-01-22 14:37:14 +00001733 * yes * 1 INTR_NEVER
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001734 * no 1 1 INTR_WHILE_WAIT
Roland McGrath54cc1c82007-11-03 23:34:11 +00001735 */
1736
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001737 sigemptyset(&empty_set);
1738 sigemptyset(&blocked_set);
1739
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001740 /* startup_child() must be called before the signal handlers get
1741 * installed below as they are inherited into the spawned process.
1742 * Also we do not need to be protected by them as during interruption
1743 * in the startup_child() mode we kill the spawned process anyway.
1744 */
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001745 if (argv[0]) {
Dmitry V. Levin1d2435b2013-05-14 22:35:46 +00001746 if (!NOMMU_SYSTEM || daemonized_tracer)
1747 hide_log_until_execve = 1;
Denys Vlasenko2a3d2752013-05-14 16:07:46 +02001748 skip_one_b_execve = 1;
Denys Vlasenko837399a2012-01-24 11:37:03 +01001749 startup_child(argv);
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001750 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001751
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001752 sa.sa_handler = SIG_IGN;
1753 sigemptyset(&sa.sa_mask);
1754 sa.sa_flags = 0;
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001755 sigaction(SIGTTOU, &sa, NULL); /* SIG_IGN */
1756 sigaction(SIGTTIN, &sa, NULL); /* SIG_IGN */
1757 if (opt_intr != INTR_ANYWHERE) {
1758 if (opt_intr == INTR_BLOCK_TSTP_TOO)
1759 sigaction(SIGTSTP, &sa, NULL); /* SIG_IGN */
1760 /*
1761 * In interactive mode (if no -o OUTFILE, or -p PID is used),
1762 * fatal signals are blocked while syscall stop is processed,
1763 * and acted on in between, when waiting for new syscall stops.
1764 * In non-interactive mode, signals are ignored.
1765 */
1766 if (opt_intr == INTR_WHILE_WAIT) {
1767 sigaddset(&blocked_set, SIGHUP);
1768 sigaddset(&blocked_set, SIGINT);
1769 sigaddset(&blocked_set, SIGQUIT);
1770 sigaddset(&blocked_set, SIGPIPE);
1771 sigaddset(&blocked_set, SIGTERM);
1772 sa.sa_handler = interrupt;
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001773 }
1774 /* SIG_IGN, or set handler for these */
1775 sigaction(SIGHUP, &sa, NULL);
1776 sigaction(SIGINT, &sa, NULL);
1777 sigaction(SIGQUIT, &sa, NULL);
1778 sigaction(SIGPIPE, &sa, NULL);
1779 sigaction(SIGTERM, &sa, NULL);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001780 }
Denys Vlasenkofd883382012-03-09 13:03:41 +01001781 if (nprocs != 0 || daemonized_tracer)
Roland McGrath02203312007-06-11 22:06:31 +00001782 startup_attach();
Roland McGrath02203312007-06-11 22:06:31 +00001783
Denys Vlasenkofd883382012-03-09 13:03:41 +01001784 /* Do we want pids printed in our -o OUTFILE?
1785 * -ff: no (every pid has its own file); or
1786 * -f: yes (there can be more pids in the future); or
1787 * -p PID1,PID2: yes (there are already more than one pid)
1788 */
1789 print_pid_pfx = (outfname && followfork < 2 && (followfork == 1 || nprocs > 1));
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001790}
1791
Denys Vlasenkoeebb04d2012-01-27 15:24:48 +01001792static struct tcb *
Roland McGrath54e931f2010-09-14 18:59:20 -07001793pid2tcb(int pid)
1794{
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +00001795 unsigned int i;
Roland McGrath54e931f2010-09-14 18:59:20 -07001796
1797 if (pid <= 0)
1798 return NULL;
1799
1800 for (i = 0; i < tcbtabsize; i++) {
1801 struct tcb *tcp = tcbtab[i];
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001802 if (tcp->pid == pid)
Roland McGrath54e931f2010-09-14 18:59:20 -07001803 return tcp;
1804 }
1805
1806 return NULL;
1807}
1808
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001809static void
Denys Vlasenko12014262011-05-30 14:00:14 +02001810cleanup(void)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001811{
Dmitry V. Levin3ed5d022014-09-10 13:46:04 +00001812 unsigned int i;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001813 struct tcb *tcp;
Denys Vlasenko35218842012-01-29 21:17:56 +01001814 int fatal_sig;
1815
1816 /* 'interrupted' is a volatile object, fetch it only once */
1817 fatal_sig = interrupted;
1818 if (!fatal_sig)
1819 fatal_sig = SIGTERM;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001820
Roland McGrathee9d4352002-12-18 04:16:10 +00001821 for (i = 0; i < tcbtabsize; i++) {
1822 tcp = tcbtab[i];
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001823 if (!tcp->pid)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001824 continue;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001825 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001826 error_msg("cleanup: looking at pid %u", tcp->pid);
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001827 if (tcp->pid == strace_child) {
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001828 kill(tcp->pid, SIGCONT);
Denys Vlasenkoa3559252012-01-29 16:43:51 +01001829 kill(tcp->pid, fatal_sig);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001830 }
Denys Vlasenko7de265d2012-03-13 11:44:31 +01001831 detach(tcp);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001832 }
1833 if (cflag)
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001834 call_summary(shared_log);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001835}
1836
1837static void
Denys Vlasenko12014262011-05-30 14:00:14 +02001838interrupt(int sig)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001839{
Denys Vlasenkoa3559252012-01-29 16:43:51 +01001840 interrupted = sig;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001841}
1842
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02001843static void
Dmitry V. Levin0f4ad302015-02-22 02:13:04 +00001844print_debug_info(const int pid, int status)
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001845{
1846 const unsigned int event = (unsigned int) status >> 16;
1847 char buf[sizeof("WIFEXITED,exitcode=%u") + sizeof(int)*3 /*paranoia:*/ + 16];
1848 char evbuf[sizeof(",EVENT_VFORK_DONE (%u)") + sizeof(int)*3 /*paranoia:*/ + 16];
1849
1850 strcpy(buf, "???");
1851 if (WIFSIGNALED(status))
1852#ifdef WCOREDUMP
1853 sprintf(buf, "WIFSIGNALED,%ssig=%s",
1854 WCOREDUMP(status) ? "core," : "",
1855 signame(WTERMSIG(status)));
1856#else
1857 sprintf(buf, "WIFSIGNALED,sig=%s",
1858 signame(WTERMSIG(status)));
1859#endif
1860 if (WIFEXITED(status))
1861 sprintf(buf, "WIFEXITED,exitcode=%u", WEXITSTATUS(status));
1862 if (WIFSTOPPED(status))
1863 sprintf(buf, "WIFSTOPPED,sig=%s", signame(WSTOPSIG(status)));
1864#ifdef WIFCONTINUED
1865 /* Should never be seen */
1866 if (WIFCONTINUED(status))
1867 strcpy(buf, "WIFCONTINUED");
1868#endif
1869 evbuf[0] = '\0';
1870 if (event != 0) {
1871 static const char *const event_names[] = {
1872 [PTRACE_EVENT_CLONE] = "CLONE",
1873 [PTRACE_EVENT_FORK] = "FORK",
1874 [PTRACE_EVENT_VFORK] = "VFORK",
1875 [PTRACE_EVENT_VFORK_DONE] = "VFORK_DONE",
1876 [PTRACE_EVENT_EXEC] = "EXEC",
1877 [PTRACE_EVENT_EXIT] = "EXIT",
1878 /* [PTRACE_EVENT_STOP (=128)] would make biggish array */
1879 };
1880 const char *e = "??";
1881 if (event < ARRAY_SIZE(event_names))
1882 e = event_names[event];
1883 else if (event == PTRACE_EVENT_STOP)
1884 e = "STOP";
1885 sprintf(evbuf, ",EVENT_%s (%u)", e, event);
1886 }
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001887 error_msg("[wait(0x%06x) = %u] %s%s", status, pid, buf, evbuf);
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001888}
1889
1890static struct tcb *
Dmitry V. Levin0f4ad302015-02-22 02:13:04 +00001891maybe_allocate_tcb(const int pid, int status)
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001892{
1893 if (!WIFSTOPPED(status)) {
Dmitry V. Levinaa801922015-02-07 18:48:55 +00001894 if (detach_on_execve && pid == strace_child) {
1895 /* example: strace -bexecve sh -c 'exec true' */
1896 strace_child = 0;
1897 return NULL;
1898 }
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001899 /*
1900 * This can happen if we inherited an unknown child.
Dmitry V. Levinaa801922015-02-07 18:48:55 +00001901 * Example: (sleep 1 & exec strace true)
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001902 */
1903 error_msg("Exit of unknown pid %u ignored", pid);
1904 return NULL;
1905 }
1906 if (followfork) {
1907 /* We assume it's a fork/vfork/clone child */
1908 struct tcb *tcp = alloctcb(pid);
1909 tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
1910 newoutf(tcp);
1911 if (!qflag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00001912 error_msg("Process %d attached", pid);
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001913 return tcp;
1914 } else {
1915 /* This can happen if a clone call used
1916 * CLONE_PTRACE itself.
1917 */
1918 ptrace(PTRACE_CONT, pid, (char *) 0, 0);
1919 error_msg("Stop of unknown pid %u seen, PTRACE_CONTed it", pid);
1920 return NULL;
1921 }
1922}
1923
1924static struct tcb *
1925maybe_switch_tcbs(struct tcb *tcp, const int pid)
1926{
1927 FILE *fp;
1928 struct tcb *execve_thread;
1929 long old_pid = 0;
1930
1931 if (ptrace(PTRACE_GETEVENTMSG, pid, NULL, (long) &old_pid) < 0)
1932 return tcp;
1933 /* Avoid truncation in pid2tcb() param passing */
1934 if (old_pid <= 0 || old_pid == pid)
1935 return tcp;
1936 if ((unsigned long) old_pid > UINT_MAX)
1937 return tcp;
1938 execve_thread = pid2tcb(old_pid);
1939 /* It should be !NULL, but I feel paranoid */
1940 if (!execve_thread)
1941 return tcp;
1942
1943 if (execve_thread->curcol != 0) {
1944 /*
1945 * One case we are here is -ff:
1946 * try "strace -oLOG -ff test/threaded_execve"
1947 */
1948 fprintf(execve_thread->outf, " <pid changed to %d ...>\n", pid);
1949 /*execve_thread->curcol = 0; - no need, see code below */
1950 }
1951 /* Swap output FILEs (needed for -ff) */
1952 fp = execve_thread->outf;
1953 execve_thread->outf = tcp->outf;
1954 tcp->outf = fp;
1955 /* And their column positions */
1956 execve_thread->curcol = tcp->curcol;
1957 tcp->curcol = 0;
1958 /* Drop leader, but close execve'd thread outfile (if -ff) */
1959 droptcb(tcp);
1960 /* Switch to the thread, reusing leader's outfile and pid */
1961 tcp = execve_thread;
1962 tcp->pid = pid;
1963 if (cflag != CFLAG_ONLY_STATS) {
1964 printleader(tcp);
1965 tprintf("+++ superseded by execve in pid %lu +++\n", old_pid);
1966 line_ended();
1967 tcp->flags |= TCB_REPRINT;
1968 }
1969
1970 return tcp;
1971}
1972
1973static void
Dmitry V. Levin0f4ad302015-02-22 02:13:04 +00001974print_signalled(struct tcb *tcp, const int pid, int status)
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001975{
Dmitry V. Levin2cd488b2015-02-07 19:41:48 +00001976 if (pid == strace_child) {
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001977 exit_code = 0x100 | WTERMSIG(status);
Dmitry V. Levin2cd488b2015-02-07 19:41:48 +00001978 strace_child = 0;
1979 }
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001980
1981 if (cflag != CFLAG_ONLY_STATS
1982 && (qual_flags[WTERMSIG(status)] & QUAL_SIGNAL)
1983 ) {
1984 printleader(tcp);
1985#ifdef WCOREDUMP
1986 tprintf("+++ killed by %s %s+++\n",
1987 signame(WTERMSIG(status)),
1988 WCOREDUMP(status) ? "(core dumped) " : "");
1989#else
1990 tprintf("+++ killed by %s +++\n",
1991 signame(WTERMSIG(status)));
1992#endif
1993 line_ended();
1994 }
1995}
1996
1997static void
Dmitry V. Levin0f4ad302015-02-22 02:13:04 +00001998print_exited(struct tcb *tcp, const int pid, int status)
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00001999{
Dmitry V. Levin2cd488b2015-02-07 19:41:48 +00002000 if (pid == strace_child) {
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002001 exit_code = WEXITSTATUS(status);
Dmitry V. Levin2cd488b2015-02-07 19:41:48 +00002002 strace_child = 0;
2003 }
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002004
2005 if (cflag != CFLAG_ONLY_STATS &&
2006 qflag < 2) {
2007 printleader(tcp);
2008 tprintf("+++ exited with %d +++\n", WEXITSTATUS(status));
2009 line_ended();
2010 }
2011}
2012
2013static void
2014print_stopped(struct tcb *tcp, const siginfo_t *si, const unsigned int sig)
2015{
2016 if (cflag != CFLAG_ONLY_STATS
2017 && !hide_log_until_execve
2018 && (qual_flags[sig] & QUAL_SIGNAL)
2019 ) {
2020 printleader(tcp);
2021 if (si) {
2022 tprintf("--- %s ", signame(sig));
2023 printsiginfo(si, verbose(tcp));
2024 tprints(" ---\n");
2025 } else
2026 tprintf("--- stopped by %s ---\n", signame(sig));
2027 line_ended();
2028 }
2029}
2030
Denys Vlasenko4bb2ffd2015-03-21 18:13:45 +01002031static void
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002032startup_tcb(struct tcb *tcp)
2033{
2034 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00002035 error_msg("pid %d has TCB_STARTUP, initializing it", tcp->pid);
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002036
2037 tcp->flags &= ~TCB_STARTUP;
2038
Dmitry V. Levin23ce9e42015-02-08 13:05:53 +00002039 if (!use_seize) {
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002040 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00002041 error_msg("setting opts 0x%x on pid %d",
2042 ptrace_setoptions, tcp->pid);
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002043 if (ptrace(PTRACE_SETOPTIONS, tcp->pid, NULL, ptrace_setoptions) < 0) {
2044 if (errno != ESRCH) {
2045 /* Should never happen, really */
2046 perror_msg_and_die("PTRACE_SETOPTIONS");
2047 }
2048 }
2049 }
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002050}
2051
2052/* Returns true iff the main trace loop has to continue. */
2053static bool
Denys Vlasenko12014262011-05-30 14:00:14 +02002054trace(void)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002055{
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002056 int pid;
2057 int wait_errno;
2058 int status;
2059 bool stopped;
2060 unsigned int sig;
2061 unsigned int event;
2062 struct tcb *tcp;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002063 struct rusage ru;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002064
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002065 if (interrupted)
2066 return false;
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01002067
Denys Vlasenko364728d2015-03-21 18:40:53 +01002068 /*
2069 * Used to exit simply when nprocs hits zero, but in this testcase:
2070 * int main() { _exit(!!fork()); }
2071 * under strace -f, parent sometimes (rarely) manages
2072 * to exit before we see the first stop of the child,
2073 * and we are losing track of it:
2074 * 19923 clone(...) = 19924
2075 * 19923 exit_group(1) = ?
2076 * 19923 +++ exited with 1 +++
2077 * Exiting only when wait() returns ECHILD works better.
2078 */
2079 if (popen_pid != 0) {
2080 /* However, if -o|logger is in use, we can't do that.
2081 * Can work around that by double-forking the logger,
2082 * but that loses the ability to wait for its completion
2083 * on exit. Oh well...
2084 */
2085 if (nprocs == 0)
2086 return false;
2087 }
Denys Vlasenko725dd422013-06-20 11:06:58 +02002088
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002089 if (interactive)
2090 sigprocmask(SIG_SETMASK, &empty_set, NULL);
2091 pid = wait4(-1, &status, __WALL, (cflag ? &ru : NULL));
2092 wait_errno = errno;
2093 if (interactive)
2094 sigprocmask(SIG_BLOCK, &blocked_set, NULL);
Denys Vlasenko7c41ce22013-07-08 13:55:04 +02002095
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002096 if (pid < 0) {
2097 if (wait_errno == EINTR)
2098 return true;
2099 if (nprocs == 0 && wait_errno == ECHILD)
2100 return false;
2101 /*
2102 * If nprocs > 0, ECHILD is not expected,
2103 * treat it as any other error here:
2104 */
2105 errno = wait_errno;
2106 perror_msg_and_die("wait4(__WALL)");
2107 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002108
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002109 if (pid == popen_pid) {
2110 if (!WIFSTOPPED(status))
2111 popen_pid = 0;
2112 return true;
2113 }
Denys Vlasenko725dd422013-06-20 11:06:58 +02002114
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002115 if (debug_flag)
2116 print_debug_info(pid, status);
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01002117
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002118 /* Look up 'pid' in our table. */
2119 tcp = pid2tcb(pid);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002120
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002121 if (!tcp) {
2122 tcp = maybe_allocate_tcb(pid, status);
2123 if (!tcp)
2124 return true;
2125 }
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01002126
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002127 if (WIFSTOPPED(status))
2128 get_regs(pid);
Dmitry V. Levine9bfff62015-02-13 22:45:33 +00002129 else
2130 clear_regs();
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002131
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002132 event = (unsigned int) status >> 16;
Denys Vlasenkoce7d9532013-02-05 16:36:13 +01002133
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002134 if (event == PTRACE_EVENT_EXEC) {
2135 /*
2136 * Under Linux, execve changes pid to thread leader's pid,
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002137 * and we see this changed pid on EVENT_EXEC and later,
2138 * execve sysexit. Leader "disappears" without exit
2139 * notification. Let user know that, drop leader's tcb,
2140 * and fix up pid in execve thread's tcb.
2141 * Effectively, execve thread's tcb replaces leader's tcb.
2142 *
2143 * BTW, leader is 'stuck undead' (doesn't report WIFEXITED
2144 * on exit syscall) in multithreaded programs exactly
2145 * in order to handle this case.
2146 *
2147 * PTRACE_GETEVENTMSG returns old pid starting from Linux 3.0.
2148 * On 2.6 and earlier, it can return garbage.
2149 */
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002150 if (os_release >= KERNEL_VERSION(3,0,0))
2151 tcp = maybe_switch_tcbs(tcp, pid);
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002152
Dmitry V. Levine6908132015-02-07 17:47:53 +00002153 if (detach_on_execve && !skip_one_b_execve) {
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002154 detach(tcp); /* do "-b execve" thingy */
Dmitry V. Levine6908132015-02-07 17:47:53 +00002155 return true;
2156 }
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002157 skip_one_b_execve = 0;
2158 }
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002159
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002160 /* Set current output file */
2161 current_tcp = tcp;
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002162
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002163 if (cflag) {
2164 tv_sub(&tcp->dtime, &ru.ru_stime, &tcp->stime);
2165 tcp->stime = ru.ru_stime;
2166 }
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002167
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002168 if (WIFSIGNALED(status)) {
2169 print_signalled(tcp, pid, status);
2170 droptcb(tcp);
2171 return true;
2172 }
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002173
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002174 if (WIFEXITED(status)) {
2175 print_exited(tcp, pid, status);
2176 droptcb(tcp);
2177 return true;
2178 }
Roland McGratheb9e2e82009-06-02 16:49:22 -07002179
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002180 if (!WIFSTOPPED(status)) {
2181 /*
2182 * Neither signalled, exited or stopped.
2183 * How could that be?
2184 */
2185 error_msg("pid %u not stopped!", pid);
2186 droptcb(tcp);
2187 return true;
2188 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002189
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002190 /* Is this the very first time we see this tracee stopped? */
2191 if (tcp->flags & TCB_STARTUP) {
Denys Vlasenko4bb2ffd2015-03-21 18:13:45 +01002192 startup_tcb(tcp);
Denys Vlasenko8497b622015-03-21 17:51:52 +01002193 if (get_scno(tcp) == 1)
2194 tcp->s_prev_ent = tcp->s_ent;
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002195 }
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002196
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002197 sig = WSTOPSIG(status);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002198
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002199 if (event != 0) {
2200 /* Ptrace event */
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01002201#if USE_SEIZE
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002202 if (event == PTRACE_EVENT_STOP) {
2203 /*
2204 * PTRACE_INTERRUPT-stop or group-stop.
2205 * PTRACE_INTERRUPT-stop has sig == SIGTRAP here.
2206 */
2207 switch (sig) {
2208 case SIGSTOP:
2209 case SIGTSTP:
2210 case SIGTTIN:
2211 case SIGTTOU:
2212 stopped = true;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002213 goto show_stopsig;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002214 }
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002215 }
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002216#endif
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002217 goto restart_tracee_with_sig_0;
2218 }
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002219
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002220 /*
2221 * Is this post-attach SIGSTOP?
2222 * Interestingly, the process may stop
2223 * with STOPSIG equal to some other signal
2224 * than SIGSTOP if we happend to attach
2225 * just before the process takes a signal.
2226 */
2227 if (sig == SIGSTOP && (tcp->flags & TCB_IGNORE_ONE_SIGSTOP)) {
2228 if (debug_flag)
Dmitry V. Levin6c8ef052015-05-25 22:51:19 +00002229 error_msg("ignored SIGSTOP on pid %d", tcp->pid);
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002230 tcp->flags &= ~TCB_IGNORE_ONE_SIGSTOP;
2231 goto restart_tracee_with_sig_0;
2232 }
2233
2234 if (sig != syscall_trap_sig) {
Dmitry V. Levin135f5cf2015-09-18 13:04:02 +00002235 siginfo_t si = {};
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002236
2237 /*
2238 * True if tracee is stopped by signal
2239 * (as opposed to "tracee received signal").
2240 * TODO: shouldn't we check for errno == EINVAL too?
2241 * We can get ESRCH instead, you know...
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002242 */
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002243 stopped = ptrace(PTRACE_GETSIGINFO, pid, 0, (long) &si) < 0;
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01002244#if USE_SEIZE
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002245show_stopsig:
Denys Vlasenko67038162012-01-29 16:46:46 +01002246#endif
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002247 print_stopped(tcp, stopped ? NULL : &si, sig);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002248
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002249 if (!stopped)
2250 /* It's signal-delivery-stop. Inject the signal */
Denys Vlasenko6cda73f2011-09-02 16:23:53 +02002251 goto restart_tracee;
Denys Vlasenko2ecba322011-08-21 17:35:39 +02002252
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002253 /* It's group-stop */
2254 if (use_seize) {
2255 /*
2256 * This ends ptrace-stop, but does *not* end group-stop.
2257 * This makes stopping signals work properly on straced process
2258 * (that is, process really stops. It used to continue to run).
Denys Vlasenkof2025022012-03-09 15:29:45 +01002259 */
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002260 if (ptrace_restart(PTRACE_LISTEN, tcp, 0) < 0) {
2261 /* Note: ptrace_restart emitted error message */
2262 exit_code = 1;
2263 return false;
2264 }
2265 return true;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002266 }
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002267 /* We don't have PTRACE_LISTEN support... */
2268 goto restart_tracee;
2269 }
2270
2271 /* We handled quick cases, we are permitted to interrupt now. */
2272 if (interrupted)
2273 return false;
2274
2275 /*
2276 * This should be syscall entry or exit.
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002277 * Handle it.
2278 */
2279 if (trace_syscall(tcp) < 0) {
2280 /*
2281 * ptrace() failed in trace_syscall().
2282 * Likely a result of process disappearing mid-flight.
2283 * Observed case: exit_group() or SIGKILL terminating
2284 * all processes in thread group.
2285 * We assume that ptrace error was caused by process death.
2286 * We used to detach(tcp) here, but since we no longer
2287 * implement "detach before death" policy/hack,
2288 * we can let this process to report its death to us
2289 * normally, via WIFEXITED or WIFSIGNALED wait status.
2290 */
2291 return true;
2292 }
2293
2294restart_tracee_with_sig_0:
2295 sig = 0;
2296
2297restart_tracee:
2298 if (ptrace_restart(PTRACE_SYSCALL, tcp, sig) < 0) {
2299 /* Note: ptrace_restart emitted error message */
2300 exit_code = 1;
2301 return false;
2302 }
2303
2304 return true;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002305}
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002306
2307int
2308main(int argc, char *argv[])
2309{
2310 init(argc, argv);
2311
Dmitry V. Levin4b4ec122015-02-07 17:31:54 +00002312 while (trace())
2313 ;
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002314
2315 cleanup();
2316 fflush(NULL);
Dmitry V. Levincf534362012-07-12 20:54:46 +00002317 if (shared_log != stderr)
2318 fclose(shared_log);
2319 if (popen_pid) {
2320 while (waitpid(popen_pid, NULL, 0) < 0 && errno == EINTR)
2321 ;
2322 }
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002323 if (exit_code > 0xff) {
2324 /* Avoid potential core file clobbering. */
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00002325 struct_rlimit rlim = {0, 0};
2326 set_rlimit(RLIMIT_CORE, &rlim);
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002327
2328 /* Child was killed by a signal, mimic that. */
2329 exit_code &= 0xff;
2330 signal(exit_code, SIG_DFL);
2331 raise(exit_code);
2332 /* Paranoia - what if this signal is not fatal?
2333 Exit with 128 + signo then. */
2334 exit_code += 128;
2335 }
2336
2337 return exit_code;
2338}