blob: 32a3f5e0d209ea63c113e337994a02de84002f2c [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>
35#include <sys/resource.h>
36#include <sys/wait.h>
37#include <sys/stat.h>
38#include <pwd.h>
39#include <grp.h>
Roland McGrath70b08532004-04-09 00:25:21 +000040#include <dirent.h>
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +010041#include <sys/utsname.h>
Dmitry V. Levin882478a2013-05-13 18:43:28 +000042#ifdef HAVE_PRCTL
43# include <sys/prctl.h>
44#endif
Denys Vlasenko84703742012-02-25 02:38:52 +010045#if defined(IA64)
Wichert Akkerman7b3346b2001-10-09 23:47:38 +000046# include <asm/ptrace_offsets.h>
47#endif
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010048/* In some libc, these aren't declared. Do it ourself: */
Denys Vlasenko96d5a762008-12-29 19:13:27 +000049extern char **environ;
Denys Vlasenko418d66a2009-01-17 01:52:54 +000050extern int optind;
51extern char *optarg;
Denys Vlasenko96d5a762008-12-29 19:13:27 +000052
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010053
54#if defined __NR_tkill
55# define my_tkill(tid, sig) syscall(__NR_tkill, (tid), (sig))
56#else
57 /* kill() may choose arbitrarily the target task of the process group
58 while we later wait on a that specific TID. PID process waits become
59 TID task specific waits for a process under ptrace(2). */
Denys Vlasenko978fbc92012-09-13 10:28:43 +020060# warning "tkill(2) not available, risk of strace hangs!"
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010061# define my_tkill(tid, sig) kill((tid), (sig))
62#endif
63
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +010064/* Glue for systems without a MMU that cannot provide fork() */
65#if !defined(HAVE_FORK)
66# undef NOMMU_SYSTEM
67# define NOMMU_SYSTEM 1
68#endif
69#if NOMMU_SYSTEM
70# define fork() vfork()
71#endif
72
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010073cflag_t cflag = CFLAG_NONE;
74unsigned int followfork = 0;
Denys Vlasenkof44cce42011-06-21 14:34:10 +020075unsigned int ptrace_setoptions = 0;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010076unsigned int xflag = 0;
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +010077bool need_fork_exec_workarounds = 0;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010078bool debug_flag = 0;
79bool Tflag = 0;
Anton Blancharda34dead2013-07-12 12:22:06 +020080bool iflag = 0;
Daniel P. Berrange01997cf2013-05-13 11:30:55 +010081unsigned int qflag = 0;
Denys Vlasenko3454e4b2011-05-23 21:29:03 +020082/* Which WSTOPSIG(status) value marks syscall traps? */
Denys Vlasenko75422762011-05-27 14:36:01 +020083static unsigned int syscall_trap_sig = SIGTRAP;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010084static unsigned int tflag = 0;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +010085static bool rflag = 0;
86static bool print_pid_pfx = 0;
Denys Vlasenkob51581e2012-01-29 16:53:03 +010087
88/* -I n */
89enum {
90 INTR_NOT_SET = 0,
91 INTR_ANYWHERE = 1, /* don't block/ignore any signals */
92 INTR_WHILE_WAIT = 2, /* block fatal signals while decoding syscall. default */
93 INTR_NEVER = 3, /* block fatal signals. default if '-o FILE PROG' */
94 INTR_BLOCK_TSTP_TOO = 4, /* block fatal signals and SIGTSTP (^Z) */
95 NUM_INTR_OPTS
96};
97static int opt_intr;
98/* We play with signal mask only if this mode is active: */
99#define interactive (opt_intr == INTR_WHILE_WAIT)
100
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000101/*
102 * daemonized_tracer supports -D option.
103 * With this option, strace forks twice.
104 * Unlike normal case, with -D *grandparent* process exec's,
105 * becoming a traced process. Child exits (this prevents traced process
106 * from having children it doesn't expect to have), and grandchild
107 * attaches to grandparent similarly to strace -p PID.
108 * This allows for more transparent interaction in cases
109 * when process and its parent are communicating via signals,
110 * wait() etc. Without -D, strace process gets lodged in between,
111 * disrupting parent<->child link.
112 */
113static bool daemonized_tracer = 0;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000114
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +0100115#if USE_SEIZE
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100116static int post_attach_sigstop = TCB_IGNORE_ONE_SIGSTOP;
117# define use_seize (post_attach_sigstop == 0)
118#else
119# define post_attach_sigstop TCB_IGNORE_ONE_SIGSTOP
120# define use_seize 0
121#endif
122
Michal Ludvig17f8fb32002-11-06 13:17:21 +0000123/* Sometimes we want to print only succeeding syscalls. */
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +0100124bool not_failing_only = 0;
Michal Ludvig17f8fb32002-11-06 13:17:21 +0000125
Grant Edwards8a082772011-04-07 20:25:40 +0000126/* Show path associated with fd arguments */
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +0100127bool show_fd_path = 0;
Grant Edwards8a082772011-04-07 20:25:40 +0000128
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100129static bool detach_on_execve = 0;
Denys Vlasenko2a3d2752013-05-14 16:07:46 +0200130/* Are we "strace PROG" and need to skip detach on first execve? */
131static bool skip_one_b_execve = 0;
132/* Are we "strace PROG" and need to hide everything until execve? */
133bool hide_log_until_execve = 0;
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100134
Dmitry V. Levina6809652008-11-10 17:14:58 +0000135static int exit_code = 0;
136static int strace_child = 0;
Denys Vlasenko75422762011-05-27 14:36:01 +0200137static int strace_tracer_pid = 0;
Roland McGratheb9e2e82009-06-02 16:49:22 -0700138
Dmitry V. Levinb9fe0112006-12-13 16:59:44 +0000139static char *username = NULL;
Denys Vlasenkoead73bd2011-06-24 22:49:58 +0200140static uid_t run_uid;
141static gid_t run_gid;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000142
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +0100143unsigned int max_strlen = DEFAULT_STRLEN;
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000144static int acolumn = DEFAULT_ACOLUMN;
Denys Vlasenko102ec492011-08-25 01:27:59 +0200145static char *acolumn_spaces;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100146
Dmitry V. Levinb9fe0112006-12-13 16:59:44 +0000147static char *outfname = NULL;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100148/* If -ff, points to stderr. Else, it's our common output log */
149static FILE *shared_log;
150
Denys Vlasenko000b6012012-01-28 01:25:03 +0100151struct tcb *printing_tcp = NULL;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100152static struct tcb *current_tcp;
153
Denys Vlasenkoead73bd2011-06-24 22:49:58 +0200154static struct tcb **tcbtab;
Denys Vlasenko2b60c352011-06-22 12:45:25 +0200155static unsigned int nprocs, tcbtabsize;
Denys Vlasenkoead73bd2011-06-24 22:49:58 +0200156static const char *progname;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000157
Denys Vlasenkoeec8d5d2013-02-14 03:29:48 +0100158unsigned os_release; /* generated from uname()'s u.release */
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +0100159
Denys Vlasenko4a9ba982013-06-20 11:20:23 +0200160static void detach(struct tcb *tcp);
Andreas Schwabe5355de2009-10-27 16:56:43 +0100161static void cleanup(void);
162static void interrupt(int sig);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000163static sigset_t empty_set, blocked_set;
164
165#ifdef HAVE_SIG_ATOMIC_T
166static volatile sig_atomic_t interrupted;
Denys Vlasenkoa3559252012-01-29 16:43:51 +0100167#else
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000168static volatile int interrupted;
Denys Vlasenkoa3559252012-01-29 16:43:51 +0100169#endif
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000170
Denys Vlasenko2c4fb902012-03-15 17:24:49 +0100171#ifndef HAVE_STRERROR
172
173#if !HAVE_DECL_SYS_ERRLIST
174extern int sys_nerr;
175extern char *sys_errlist[];
Denys Vlasenkoa6d91de2012-03-16 12:02:22 +0100176#endif
Denys Vlasenko2c4fb902012-03-15 17:24:49 +0100177
178const char *
179strerror(int err_no)
180{
181 static char buf[sizeof("Unknown error %d") + sizeof(int)*3];
182
183 if (err_no < 1 || err_no >= sys_nerr) {
184 sprintf(buf, "Unknown error %d", err_no);
185 return buf;
186 }
187 return sys_errlist[err_no];
188}
189
190#endif /* HAVE_STERRROR */
191
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000192static void
Denys Vlasenkocb2ad002011-06-23 13:05:29 +0200193usage(FILE *ofp, int exitval)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000194{
195 fprintf(ofp, "\
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +0200196usage: strace [-CdffhiqrtttTvVxxy] [-I n] [-e expr]...\n\
197 [-a column] [-o file] [-s strsize] [-P path]...\n\
198 -p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]\n\
199 or: strace -c[df] [-I n] [-e expr]... [-O overhead] [-S sortby]\n\
200 -p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]\n\
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000201-c -- count time, calls, and errors for each syscall and report summary\n\
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +0200202-C -- like -c but also print regular output\n\
Denys Vlasenko3e084ac2012-03-15 13:39:05 +0100203-d -- enable debug output to stderr\n\
Denys Vlasenkob51581e2012-01-29 16:53:03 +0100204-D -- run tracer process as a detached grandchild, not as parent\n\
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000205-f -- follow forks, -ff -- with output into separate files\n\
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000206-i -- print instruction pointer at time of syscall\n\
207-q -- suppress messages about attaching, detaching, etc.\n\
208-r -- print relative timestamp, -t -- absolute timestamp, -tt -- with usecs\n\
Denys Vlasenkocdab1be2012-02-03 12:17:57 +0100209-T -- print time spent in each syscall\n\
210-v -- verbose mode: print unabbreviated argv, stat, termios, etc. args\n\
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000211-x -- print non-ascii strings in hex, -xx -- print all strings in hex\n\
Grant Edwards8a082772011-04-07 20:25:40 +0000212-y -- print paths associated with file descriptor arguments\n\
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +0200213-h -- print help message, -V -- print version\n\
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000214-a column -- alignment COLUMN for printing syscall results (default %d)\n\
Denys Vlasenko22efaf02013-02-27 12:15:19 +0100215-b execve -- detach on this syscall\n\
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000216-e expr -- a qualifying expression: option=[!]all or option=[!]val1[,val2]...\n\
Denys Vlasenko38e79bb2013-02-26 11:33:54 +0100217 options: trace, abbrev, verbose, raw, signal, read, write\n\
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +0200218-I interruptible --\n\
219 1: no signals are blocked\n\
220 2: fatal signals are blocked while decoding syscall (default)\n\
221 3: fatal signals are always blocked (default if '-o FILE PROG')\n\
222 4: fatal signals and SIGTSTP (^Z) are always blocked\n\
223 (useful to make 'strace -o FILE PROG' not stop on ^Z)\n\
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000224-o file -- send trace output to FILE instead of stderr\n\
225-O overhead -- set overhead for tracing syscalls to OVERHEAD usecs\n\
226-p pid -- trace process with process id PID, may be repeated\n\
227-s strsize -- limit length of print strings to STRSIZE chars (default %d)\n\
228-S sortby -- sort syscall counts by: time, calls, name, nothing (default %s)\n\
229-u username -- run command as username handling setuid and/or setgid\n\
Roland McGrathde6e5332003-01-24 04:31:23 +0000230-E var=val -- put var=val in the environment for command\n\
231-E var -- remove var from the environment for command\n\
Grant Edwards8a082772011-04-07 20:25:40 +0000232-P path -- trace accesses to path\n\
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100233"
Denys Vlasenko38e79bb2013-02-26 11:33:54 +0100234/* ancient, no one should use it
235-F -- attempt to follow vforks (deprecated, use -f)\n\
236 */
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100237/* this is broken, so don't document it
Michal Ludvig17f8fb32002-11-06 13:17:21 +0000238-z -- print only succeeding syscalls\n\
Denys Vlasenko61e7aad2012-03-15 13:44:17 +0100239 */
Roland McGrathde6e5332003-01-24 04:31:23 +0000240, DEFAULT_ACOLUMN, DEFAULT_STRLEN, DEFAULT_SORTBY);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +0000241 exit(exitval);
242}
243
Denys Vlasenko75422762011-05-27 14:36:01 +0200244static void die(void) __attribute__ ((noreturn));
245static void die(void)
246{
247 if (strace_tracer_pid == getpid()) {
248 cflag = 0;
249 cleanup();
250 }
251 exit(1);
252}
253
254static void verror_msg(int err_no, const char *fmt, va_list p)
Denys Vlasenko3454e4b2011-05-23 21:29:03 +0200255{
Denys Vlasenko82bb78c2012-01-24 10:17:18 +0100256 char *msg;
257
Dmitry V. Levin44d05322011-06-09 15:50:41 +0000258 fflush(NULL);
Denys Vlasenko82bb78c2012-01-24 10:17:18 +0100259
260 /* We want to print entire message with single fprintf to ensure
261 * message integrity if stderr is shared with other programs.
262 * Thus we use vasprintf + single fprintf.
263 */
264 msg = NULL;
Denys Vlasenkocfad5432012-01-24 12:48:02 +0100265 if (vasprintf(&msg, fmt, p) >= 0) {
Denys Vlasenko82bb78c2012-01-24 10:17:18 +0100266 if (err_no)
267 fprintf(stderr, "%s: %s: %s\n", progname, msg, strerror(err_no));
268 else
269 fprintf(stderr, "%s: %s\n", progname, msg);
270 free(msg);
271 } else {
272 /* malloc in vasprintf failed, try it without malloc */
273 fprintf(stderr, "%s: ", progname);
274 vfprintf(stderr, fmt, p);
275 if (err_no)
276 fprintf(stderr, ": %s\n", strerror(err_no));
277 else
278 putc('\n', stderr);
279 }
280 /* We don't switch stderr to buffered, thus fprintf(stderr)
281 * always flushes its output and this is not necessary: */
282 /* fflush(stderr); */
Denys Vlasenko75422762011-05-27 14:36:01 +0200283}
Denys Vlasenko3454e4b2011-05-23 21:29:03 +0200284
Denys Vlasenko75422762011-05-27 14:36:01 +0200285void error_msg(const char *fmt, ...)
286{
287 va_list p;
288 va_start(p, fmt);
289 verror_msg(0, fmt, p);
290 va_end(p);
291}
292
293void error_msg_and_die(const char *fmt, ...)
294{
295 va_list p;
296 va_start(p, fmt);
297 verror_msg(0, fmt, p);
298 die();
299}
300
301void perror_msg(const char *fmt, ...)
302{
303 va_list p;
304 va_start(p, fmt);
305 verror_msg(errno, fmt, p);
306 va_end(p);
307}
308
309void perror_msg_and_die(const char *fmt, ...)
310{
311 va_list p;
312 va_start(p, fmt);
313 verror_msg(errno, fmt, p);
314 die();
Denys Vlasenko3454e4b2011-05-23 21:29:03 +0200315}
316
Denys Vlasenko1d46ba52011-08-31 14:00:02 +0200317void die_out_of_memory(void)
318{
319 static bool recursed = 0;
320 if (recursed)
321 exit(1);
322 recursed = 1;
323 error_msg_and_die("Out of memory");
324}
325
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000326static void
327error_opt_arg(int opt, const char *arg)
328{
329 error_msg_and_die("Invalid -%c argument: '%s'", opt, arg);
330}
331
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +0100332#if USE_SEIZE
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100333static int
334ptrace_attach_or_seize(int pid)
335{
336 int r;
337 if (!use_seize)
Denys Vlasenkoc169d942013-07-10 14:33:05 +0200338 return ptrace(PTRACE_ATTACH, pid, 0L, 0L);
339 r = ptrace(PTRACE_SEIZE, pid, 0L, (unsigned long)ptrace_setoptions);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100340 if (r)
341 return r;
Denys Vlasenkoc169d942013-07-10 14:33:05 +0200342 r = ptrace(PTRACE_INTERRUPT, pid, 0L, 0L);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100343 return r;
344}
345#else
346# define ptrace_attach_or_seize(pid) ptrace(PTRACE_ATTACH, (pid), 0, 0)
347#endif
348
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100349/*
350 * Used when we want to unblock stopped traced process.
351 * Should be only used with PTRACE_CONT, PTRACE_DETACH and PTRACE_SYSCALL.
352 * Returns 0 on success or if error was ESRCH
353 * (presumably process was killed while we talk to it).
354 * Otherwise prints error message and returns -1.
355 */
356static int
357ptrace_restart(int op, struct tcb *tcp, int sig)
358{
359 int err;
360 const char *msg;
361
362 errno = 0;
363 ptrace(op, tcp->pid, (void *) 0, (long) sig);
364 err = errno;
Denys Vlasenko23506752012-03-21 10:32:49 +0100365 if (!err)
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100366 return 0;
367
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100368 msg = "SYSCALL";
369 if (op == PTRACE_CONT)
370 msg = "CONT";
371 if (op == PTRACE_DETACH)
372 msg = "DETACH";
373#ifdef PTRACE_LISTEN
374 if (op == PTRACE_LISTEN)
375 msg = "LISTEN";
376#endif
Denys Vlasenko23506752012-03-21 10:32:49 +0100377 /*
378 * Why curcol != 0? Otherwise sometimes we get this:
379 *
380 * 10252 kill(10253, SIGKILL) = 0
381 * <ptrace(SYSCALL,10252):No such process>10253 ...next decode...
382 *
383 * 10252 died after we retrieved syscall exit data,
384 * but before we tried to restart it. Log looks ugly.
385 */
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100386 if (current_tcp && current_tcp->curcol != 0) {
Denys Vlasenko23506752012-03-21 10:32:49 +0100387 tprintf(" <ptrace(%s):%s>\n", msg, strerror(err));
388 line_ended();
389 }
390 if (err == ESRCH)
391 return 0;
392 errno = err;
Denys Vlasenko852f98a2012-03-20 16:26:25 +0100393 perror_msg("ptrace(PTRACE_%s,pid:%d,sig:%d)", msg, tcp->pid, sig);
394 return -1;
395}
396
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200397static void
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000398set_cloexec_flag(int fd)
399{
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200400 int flags, newflags;
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000401
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200402 flags = fcntl(fd, F_GETFD);
403 if (flags < 0) {
404 /* Can happen only if fd is bad.
405 * Should never happen: if it does, we have a bug
406 * in the caller. Therefore we just abort
407 * instead of propagating the error.
408 */
409 perror_msg_and_die("fcntl(%d, F_GETFD)", fd);
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000410 }
411
412 newflags = flags | FD_CLOEXEC;
413 if (flags == newflags)
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200414 return;
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000415
Denys Vlasenko1f532ab2011-06-22 13:11:23 +0200416 fcntl(fd, F_SETFD, newflags); /* never fails */
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000417}
418
Denys Vlasenko75fe85c2012-03-09 15:15:24 +0100419static void kill_save_errno(pid_t pid, int sig)
420{
421 int saved_errno = errno;
422
423 (void) kill(pid, sig);
424 errno = saved_errno;
425}
426
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100427/*
428 * When strace is setuid executable, we have to swap uids
429 * before and after filesystem and process management operations.
430 */
431static void
432swap_uid(void)
433{
434 int euid = geteuid(), uid = getuid();
435
436 if (euid != uid && setreuid(euid, uid) < 0) {
437 perror_msg_and_die("setreuid");
438 }
439}
440
441#if _LFS64_LARGEFILE
442# define fopen_for_output fopen64
Dmitry V. Levinc8938e02013-03-20 21:40:15 +0000443# define struct_stat struct stat64
444# define stat_file stat64
445# define struct_dirent struct dirent64
446# define read_dir readdir64
447# define struct_rlimit struct rlimit64
448# define set_rlimit setrlimit64
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100449#else
450# define fopen_for_output fopen
Dmitry V. Levinc8938e02013-03-20 21:40:15 +0000451# define struct_stat struct stat
452# define stat_file stat
453# define struct_dirent struct dirent
454# define read_dir readdir
455# define struct_rlimit struct rlimit
456# define set_rlimit setrlimit
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100457#endif
458
459static FILE *
460strace_fopen(const char *path)
461{
462 FILE *fp;
463
464 swap_uid();
465 fp = fopen_for_output(path, "w");
466 if (!fp)
467 perror_msg_and_die("Can't fopen '%s'", path);
468 swap_uid();
469 set_cloexec_flag(fileno(fp));
470 return fp;
471}
472
473static int popen_pid = 0;
474
475#ifndef _PATH_BSHELL
476# define _PATH_BSHELL "/bin/sh"
477#endif
478
479/*
480 * We cannot use standard popen(3) here because we have to distinguish
481 * popen child process from other processes we trace, and standard popen(3)
482 * does not export its child's pid.
483 */
484static FILE *
485strace_popen(const char *command)
486{
487 FILE *fp;
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200488 int pid;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100489 int fds[2];
490
491 swap_uid();
492 if (pipe(fds) < 0)
493 perror_msg_and_die("pipe");
494
495 set_cloexec_flag(fds[1]); /* never fails */
496
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200497 pid = vfork();
498 if (pid < 0)
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100499 perror_msg_and_die("vfork");
500
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200501 if (pid == 0) {
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100502 /* child */
503 close(fds[1]);
504 if (fds[0] != 0) {
505 if (dup2(fds[0], 0))
506 perror_msg_and_die("dup2");
507 close(fds[0]);
508 }
509 execl(_PATH_BSHELL, "sh", "-c", command, NULL);
510 perror_msg_and_die("Can't execute '%s'", _PATH_BSHELL);
511 }
512
513 /* parent */
Denys Vlasenko519af5a2013-07-02 11:31:24 +0200514 popen_pid = pid;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100515 close(fds[0]);
516 swap_uid();
517 fp = fdopen(fds[1], "w");
518 if (!fp)
519 die_out_of_memory();
520 return fp;
521}
522
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100523void
524tprintf(const char *fmt, ...)
525{
526 va_list args;
527
528 va_start(args, fmt);
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100529 if (current_tcp) {
Denys Vlasenko6e4f3c12012-04-16 18:22:19 +0200530 int n = strace_vfprintf(current_tcp->outf, fmt, args);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100531 if (n < 0) {
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100532 if (current_tcp->outf != stderr)
Dmitry V. Levin9a71bcd2012-09-17 23:20:54 +0000533 perror_msg("%s", outfname);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100534 } else
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100535 current_tcp->curcol += n;
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100536 }
537 va_end(args);
538}
539
540void
541tprints(const char *str)
542{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100543 if (current_tcp) {
Denys Vlasenko142aee02012-04-16 18:10:15 +0200544 int n = fputs_unlocked(str, current_tcp->outf);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100545 if (n >= 0) {
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100546 current_tcp->curcol += strlen(str);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100547 return;
548 }
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100549 if (current_tcp->outf != stderr)
Dmitry V. Levin9a71bcd2012-09-17 23:20:54 +0000550 perror_msg("%s", outfname);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100551 }
552}
553
554void
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100555line_ended(void)
556{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100557 if (current_tcp) {
558 current_tcp->curcol = 0;
559 fflush(current_tcp->outf);
560 }
561 if (printing_tcp) {
562 printing_tcp->curcol = 0;
563 printing_tcp = NULL;
564 }
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100565}
566
567void
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100568printleader(struct tcb *tcp)
569{
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100570 /* If -ff, "previous tcb we printed" is always the same as current,
571 * because we have per-tcb output files.
572 */
573 if (followfork >= 2)
574 printing_tcp = tcp;
575
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100576 if (printing_tcp) {
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100577 current_tcp = printing_tcp;
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100578 if (printing_tcp->curcol != 0 && (followfork < 2 || printing_tcp == tcp)) {
579 /*
580 * case 1: we have a shared log (i.e. not -ff), and last line
581 * wasn't finished (same or different tcb, doesn't matter).
582 * case 2: split log, we are the same tcb, but our last line
583 * didn't finish ("SIGKILL nuked us after syscall entry" etc).
584 */
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100585 tprints(" <unfinished ...>\n");
Denys Vlasenko7de265d2012-03-13 11:44:31 +0100586 printing_tcp->curcol = 0;
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100587 }
588 }
589
590 printing_tcp = tcp;
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100591 current_tcp = tcp;
592 current_tcp->curcol = 0;
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100593
594 if (print_pid_pfx)
595 tprintf("%-5d ", tcp->pid);
596 else if (nprocs > 1 && !outfname)
597 tprintf("[pid %5u] ", tcp->pid);
598
599 if (tflag) {
600 char str[sizeof("HH:MM:SS")];
601 struct timeval tv, dtv;
602 static struct timeval otv;
603
604 gettimeofday(&tv, NULL);
605 if (rflag) {
606 if (otv.tv_sec == 0)
607 otv = tv;
608 tv_sub(&dtv, &tv, &otv);
609 tprintf("%6ld.%06ld ",
610 (long) dtv.tv_sec, (long) dtv.tv_usec);
611 otv = tv;
612 }
613 else if (tflag > 2) {
614 tprintf("%ld.%06ld ",
615 (long) tv.tv_sec, (long) tv.tv_usec);
616 }
617 else {
618 time_t local = tv.tv_sec;
619 strftime(str, sizeof(str), "%T", localtime(&local));
620 if (tflag > 1)
621 tprintf("%s.%06ld ", str, (long) tv.tv_usec);
622 else
623 tprintf("%s ", str);
624 }
625 }
626 if (iflag)
Denys Vlasenko5a2483b2013-07-01 12:49:14 +0200627 print_pc(tcp);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100628}
629
630void
631tabto(void)
632{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100633 if (current_tcp->curcol < acolumn)
634 tprints(acolumn_spaces + current_tcp->curcol);
Denys Vlasenko2e856a12012-03-12 23:02:26 +0100635}
636
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100637/* Should be only called directly *after successful attach* to a tracee.
638 * Otherwise, "strace -oFILE -ff -p<nonexistant_pid>"
639 * may create bogus empty FILE.<nonexistant_pid>, and then die.
640 */
Denys Vlasenko3d5ed412011-06-22 13:17:16 +0200641static void
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000642newoutf(struct tcb *tcp)
643{
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100644 tcp->outf = shared_log; /* if not -ff mode, the same file is for all */
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100645 if (followfork >= 2) {
Denys Vlasenko7a8bf062009-01-29 20:38:20 +0000646 char name[520 + sizeof(int) * 3];
Denys Vlasenko7a8bf062009-01-29 20:38:20 +0000647 sprintf(name, "%.512s.%u", outfname, tcp->pid);
Denys Vlasenko3d5ed412011-06-22 13:17:16 +0200648 tcp->outf = strace_fopen(name);
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000649 }
Dmitry V. Levin10de62b2006-12-13 21:45:31 +0000650}
651
Denys Vlasenko558e5122012-03-12 23:32:16 +0100652static void
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100653expand_tcbtab(void)
654{
655 /* Allocate some more TCBs and expand the table.
656 We don't want to relocate the TCBs because our
657 callers have pointers and it would be a pain.
658 So tcbtab is a table of pointers. Since we never
659 free the TCBs, we allocate a single chunk of many. */
660 int i = tcbtabsize;
661 struct tcb *newtcbs = calloc(tcbtabsize, sizeof(newtcbs[0]));
662 struct tcb **newtab = realloc(tcbtab, tcbtabsize * 2 * sizeof(tcbtab[0]));
663 if (!newtab || !newtcbs)
664 die_out_of_memory();
665 tcbtabsize *= 2;
666 tcbtab = newtab;
667 while (i < tcbtabsize)
668 tcbtab[i++] = newtcbs++;
669}
670
671static struct tcb *
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100672alloctcb(int pid)
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100673{
674 int i;
675 struct tcb *tcp;
676
677 if (nprocs == tcbtabsize)
678 expand_tcbtab();
679
680 for (i = 0; i < tcbtabsize; i++) {
681 tcp = tcbtab[i];
Denys Vlasenkofadbf662013-06-26 14:14:29 +0200682 if (!tcp->pid) {
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100683 memset(tcp, 0, sizeof(*tcp));
684 tcp->pid = pid;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100685#if SUPPORTED_PERSONALITIES > 1
686 tcp->currpers = current_personality;
687#endif
688 nprocs++;
689 if (debug_flag)
690 fprintf(stderr, "new tcb for pid %d, active tcbs:%d\n", tcp->pid, nprocs);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100691 return tcp;
692 }
693 }
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100694 error_msg_and_die("bug in alloctcb");
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100695}
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100696
697static void
698droptcb(struct tcb *tcp)
699{
700 if (tcp->pid == 0)
701 return;
702
703 nprocs--;
704 if (debug_flag)
705 fprintf(stderr, "dropped tcb for pid %d, %d remain\n", tcp->pid, nprocs);
706
707 if (tcp->outf) {
Denys Vlasenko8511f2a2012-03-22 09:35:51 +0100708 if (followfork >= 2) {
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100709 if (tcp->curcol != 0)
710 fprintf(tcp->outf, " <detached ...>\n");
711 fclose(tcp->outf);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100712 } else {
713 if (printing_tcp == tcp && tcp->curcol != 0)
714 fprintf(tcp->outf, " <detached ...>\n");
715 fflush(tcp->outf);
716 }
717 }
718
Denys Vlasenko6764f8f2012-03-22 09:56:20 +0100719 if (current_tcp == tcp)
720 current_tcp = NULL;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100721 if (printing_tcp == tcp)
722 printing_tcp = NULL;
723
724 memset(tcp, 0, sizeof(*tcp));
725}
726
Denys Vlasenkof1669e72013-06-18 18:09:39 +0200727/* Detach traced process.
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100728 * Never call DETACH twice on the same process as both unattached and
729 * attached-unstopped processes give the same ESRCH. For unattached process we
730 * would SIGSTOP it and wait for its SIGSTOP notification forever.
731 */
Denys Vlasenko4a9ba982013-06-20 11:20:23 +0200732static void
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100733detach(struct tcb *tcp)
734{
735 int error;
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200736 int status;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100737
738 if (tcp->flags & TCB_BPTSET)
739 clearbpt(tcp);
740
741 /*
742 * Linux wrongly insists the child be stopped
743 * before detaching. Arghh. We go through hoops
744 * to make a clean break of things.
745 */
746#if defined(SPARC)
Denys Vlasenko978fbc92012-09-13 10:28:43 +0200747# undef PTRACE_DETACH
748# define PTRACE_DETACH PTRACE_SUNDETACH
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100749#endif
750
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200751 if (!(tcp->flags & TCB_ATTACHED))
752 goto drop;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100753
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200754 /* We attached but possibly didn't see the expected SIGSTOP.
755 * We must catch exactly one as otherwise the detached process
756 * would be left stopped (process state T).
757 */
758 if (tcp->flags & TCB_IGNORE_ONE_SIGSTOP)
759 goto wait_loop;
760
761 error = ptrace(PTRACE_DETACH, tcp->pid, 0, 0);
762 if (!error) {
763 /* On a clear day, you can see forever. */
764 goto drop;
765 }
766 if (errno != ESRCH) {
767 /* Shouldn't happen. */
768 perror_msg("detach: ptrace(PTRACE_DETACH,%u)", tcp->pid);
769 goto drop;
770 }
771 /* ESRCH: process is either not stopped or doesn't exist. */
772 if (my_tkill(tcp->pid, 0) < 0) {
773 if (errno != ESRCH)
774 /* Shouldn't happen. */
775 perror_msg("detach: tkill(%u,0)", tcp->pid);
776 /* else: process doesn't exist. */
777 goto drop;
778 }
779 /* Process is not stopped, need to stop it. */
780 if (use_seize) {
781 /*
782 * With SEIZE, tracee can be in group-stop already.
783 * In this state sending it another SIGSTOP does nothing.
784 * Need to use INTERRUPT.
785 * Testcase: trying to ^C a "strace -p <stopped_process>".
786 */
787 error = ptrace(PTRACE_INTERRUPT, tcp->pid, 0, 0);
788 if (!error)
789 goto wait_loop;
790 if (errno != ESRCH)
791 perror_msg("detach: ptrace(PTRACE_INTERRUPT,%u)", tcp->pid);
792 }
793 else {
794 error = my_tkill(tcp->pid, SIGSTOP);
795 if (!error)
796 goto wait_loop;
797 if (errno != ESRCH)
798 perror_msg("detach: tkill(%u,SIGSTOP)", tcp->pid);
799 }
800 /* Either process doesn't exist, or some weird error. */
801 goto drop;
802
Denys Vlasenkoa2de9da2013-06-21 15:50:41 +0200803 wait_loop:
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200804 /* We end up here in three cases:
805 * 1. We sent PTRACE_INTERRUPT (use_seize case)
806 * 2. We sent SIGSTOP (!use_seize)
807 * 3. Attach SIGSTOP was already pending (TCB_IGNORE_ONE_SIGSTOP set)
808 */
809 for (;;) {
810 int sig;
811 if (waitpid(tcp->pid, &status, __WALL) < 0) {
812 if (errno == EINTR)
813 continue;
814 /*
815 * if (errno == ECHILD) break;
816 * ^^^ WRONG! We expect this PID to exist,
817 * and want to emit a message otherwise:
818 */
819 perror_msg("detach: waitpid(%u)", tcp->pid);
820 break;
821 }
822 if (!WIFSTOPPED(status)) {
823 /*
824 * Tracee exited or was killed by signal.
825 * We shouldn't normally reach this place:
826 * we don't want to consume exit status.
827 * Consider "strace -p PID" being ^C-ed:
828 * we want merely to detach from PID.
829 *
830 * However, we _can_ end up here if tracee
831 * was SIGKILLed.
832 */
833 break;
834 }
835 sig = WSTOPSIG(status);
836 if (debug_flag)
837 fprintf(stderr, "detach wait: event:%d sig:%d\n",
838 (unsigned)status >> 16, sig);
839 if (use_seize) {
840 unsigned event = (unsigned)status >> 16;
841 if (event == PTRACE_EVENT_STOP /*&& sig == SIGTRAP*/) {
Denys Vlasenkofdfa47a2013-06-20 12:10:21 +0200842 /*
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200843 * sig == SIGTRAP: PTRACE_INTERRUPT stop.
844 * sig == other: process was already stopped
845 * with this stopping sig (see tests/detach-stopped).
846 * Looks like re-injecting this sig is not necessary
847 * in DETACH for the tracee to remain stopped.
Denys Vlasenkofdfa47a2013-06-20 12:10:21 +0200848 */
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200849 sig = 0;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100850 }
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200851 /*
852 * PTRACE_INTERRUPT is not guaranteed to produce
853 * the above event if other ptrace-stop is pending.
854 * See tests/detach-sleeping testcase:
855 * strace got SIGINT while tracee is sleeping.
856 * We sent PTRACE_INTERRUPT.
857 * We see syscall exit, not PTRACE_INTERRUPT stop.
858 * We won't get PTRACE_INTERRUPT stop
859 * if we would CONT now. Need to DETACH.
860 */
Denys Vlasenko69e27ef2013-06-19 15:31:39 +0200861 if (sig == syscall_trap_sig)
862 sig = 0;
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200863 /* else: not sure in which case we can be here.
864 * Signal stop? Inject it while detaching.
865 */
866 ptrace_restart(PTRACE_DETACH, tcp, sig);
867 break;
868 }
869 /* Note: this check has to be after use_seize check */
870 /* (else, in use_seize case SIGSTOP will be mistreated) */
871 if (sig == SIGSTOP) {
872 /* Detach, suppressing SIGSTOP */
873 ptrace_restart(PTRACE_DETACH, tcp, 0);
874 break;
875 }
876 if (sig == syscall_trap_sig)
877 sig = 0;
878 /* Can't detach just yet, may need to wait for SIGSTOP */
879 error = ptrace_restart(PTRACE_CONT, tcp, sig);
880 if (error < 0) {
881 /* Should not happen.
882 * Note: ptrace_restart returns 0 on ESRCH, so it's not it.
883 * ptrace_restart already emitted error message.
884 */
885 break;
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100886 }
887 }
888
Denys Vlasenkoe2567d52013-06-21 16:11:10 +0200889 drop:
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100890 if (!qflag && (tcp->flags & TCB_ATTACHED))
891 fprintf(stderr, "Process %u detached\n", tcp->pid);
892
893 droptcb(tcp);
Denys Vlasenko800ec8f2012-03-16 15:11:34 +0100894}
895
896static void
Denys Vlasenko558e5122012-03-12 23:32:16 +0100897process_opt_p_list(char *opt)
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100898{
899 while (*opt) {
900 /*
901 * We accept -p PID,PID; -p "`pidof PROG`"; -p "`pgrep PROG`".
902 * pidof uses space as delim, pgrep uses newline. :(
903 */
904 int pid;
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100905 char *delim = opt + strcspn(opt, ", \n\t");
906 char c = *delim;
907
908 *delim = '\0';
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000909 pid = string_to_uint(opt);
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100910 if (pid <= 0) {
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000911 error_msg_and_die("Invalid process id: '%s'", opt);
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100912 }
913 if (pid == strace_tracer_pid) {
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000914 error_msg_and_die("I'm sorry, I can't let you do that, Dave.");
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100915 }
916 *delim = c;
Denys Vlasenko3db3b262012-03-16 15:15:14 +0100917 alloctcb(pid);
Denys Vlasenkoe8172b72012-03-09 13:01:04 +0100918 if (c == '\0')
919 break;
920 opt = delim + 1;
921 }
922}
923
Roland McGrath02203312007-06-11 22:06:31 +0000924static void
925startup_attach(void)
926{
927 int tcbi;
928 struct tcb *tcp;
929
930 /*
931 * Block user interruptions as we would leave the traced
932 * process stopped (process state T) if we would terminate in
Denys Vlasenko2e968c02011-09-01 10:23:09 +0200933 * between PTRACE_ATTACH and wait4() on SIGSTOP.
Denys Vlasenkob63256e2011-06-07 12:13:24 +0200934 * We rely on cleanup() from this point on.
Roland McGrath02203312007-06-11 22:06:31 +0000935 */
936 if (interactive)
937 sigprocmask(SIG_BLOCK, &blocked_set, NULL);
938
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000939 if (daemonized_tracer) {
940 pid_t pid = fork();
941 if (pid < 0) {
Denys Vlasenko014ca3a2011-09-02 16:19:30 +0200942 perror_msg_and_die("fork");
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000943 }
944 if (pid) { /* parent */
945 /*
Denys Vlasenko75422762011-05-27 14:36:01 +0200946 * Wait for grandchild to attach to straced process
947 * (grandparent). Grandchild SIGKILLs us after it attached.
948 * Grandparent's wait() is unblocked by our death,
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000949 * it proceeds to exec the straced program.
950 */
951 pause();
952 _exit(0); /* paranoia */
953 }
Denys Vlasenko75422762011-05-27 14:36:01 +0200954 /* grandchild */
955 /* We will be the tracer process. Remember our new pid: */
956 strace_tracer_pid = getpid();
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000957 }
958
Roland McGrath02203312007-06-11 22:06:31 +0000959 for (tcbi = 0; tcbi < tcbtabsize; tcbi++) {
960 tcp = tcbtab[tcbi];
Denys Vlasenko44f87ef2011-08-17 15:18:21 +0200961
Denys Vlasenkofadbf662013-06-26 14:14:29 +0200962 if (!tcp->pid)
Denys Vlasenko75fe85c2012-03-09 15:15:24 +0100963 continue;
964
Denys Vlasenkod116a732011-09-05 14:01:33 +0200965 /* Is this a process we should attach to, but not yet attached? */
Denys Vlasenko75fe85c2012-03-09 15:15:24 +0100966 if (tcp->flags & TCB_ATTACHED)
967 continue; /* no, we already attached it */
Denys Vlasenkod116a732011-09-05 14:01:33 +0200968
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +0000969 if (followfork && !daemonized_tracer) {
Denys Vlasenko7a8bf062009-01-29 20:38:20 +0000970 char procdir[sizeof("/proc/%d/task") + sizeof(int) * 3];
Roland McGrath02203312007-06-11 22:06:31 +0000971 DIR *dir;
972
973 sprintf(procdir, "/proc/%d/task", tcp->pid);
974 dir = opendir(procdir);
975 if (dir != NULL) {
976 unsigned int ntid = 0, nerr = 0;
Dmitry V. Levinc8938e02013-03-20 21:40:15 +0000977 struct_dirent *de;
Denys Vlasenko381dbc22011-09-05 13:59:39 +0200978
Dmitry V. Levinc8938e02013-03-20 21:40:15 +0000979 while ((de = read_dir(dir)) != NULL) {
Denys Vlasenko381dbc22011-09-05 13:59:39 +0200980 struct tcb *cur_tcp;
981 int tid;
982
Denys Vlasenko7a8bf062009-01-29 20:38:20 +0000983 if (de->d_fileno == 0)
Roland McGrath02203312007-06-11 22:06:31 +0000984 continue;
Dmitry V. Levinccee1692012-03-25 21:49:48 +0000985 /* we trust /proc filesystem */
Roland McGrath02203312007-06-11 22:06:31 +0000986 tid = atoi(de->d_name);
987 if (tid <= 0)
988 continue;
989 ++ntid;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +0100990 if (ptrace_attach_or_seize(tid) < 0) {
Roland McGrath02203312007-06-11 22:06:31 +0000991 ++nerr;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +0100992 if (debug_flag)
Denys Vlasenkof95397a2011-06-24 16:51:16 +0200993 fprintf(stderr, "attach to pid %d failed\n", tid);
Denys Vlasenko381dbc22011-09-05 13:59:39 +0200994 continue;
Denys Vlasenkof95397a2011-06-24 16:51:16 +0200995 }
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +0100996 if (debug_flag)
Denys Vlasenko381dbc22011-09-05 13:59:39 +0200997 fprintf(stderr, "attach to pid %d succeeded\n", tid);
998 cur_tcp = tcp;
999 if (tid != tcp->pid)
1000 cur_tcp = alloctcb(tid);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001001 cur_tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001002 newoutf(cur_tcp);
Roland McGrath02203312007-06-11 22:06:31 +00001003 }
1004 closedir(dir);
Denys Vlasenko381dbc22011-09-05 13:59:39 +02001005 if (interactive) {
1006 sigprocmask(SIG_SETMASK, &empty_set, NULL);
1007 if (interrupted)
1008 goto ret;
1009 sigprocmask(SIG_BLOCK, &blocked_set, NULL);
1010 }
Denys Vlasenko7a8bf062009-01-29 20:38:20 +00001011 ntid -= nerr;
1012 if (ntid == 0) {
Denys Vlasenko905e8e02013-02-26 12:30:09 +01001013 perror_msg("attach: ptrace(PTRACE_ATTACH, ...)");
Roland McGrath02203312007-06-11 22:06:31 +00001014 droptcb(tcp);
1015 continue;
1016 }
1017 if (!qflag) {
Denys Vlasenko7a8bf062009-01-29 20:38:20 +00001018 fprintf(stderr, ntid > 1
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001019? "Process %u attached with %u threads\n"
1020: "Process %u attached\n",
Denys Vlasenko44f87ef2011-08-17 15:18:21 +02001021 tcp->pid, ntid);
Roland McGrath02203312007-06-11 22:06:31 +00001022 }
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001023 if (!(tcp->flags & TCB_ATTACHED)) {
Denys Vlasenkof88837a2011-09-05 14:05:46 +02001024 /* -p PID, we failed to attach to PID itself
1025 * but did attach to some of its sibling threads.
1026 * Drop PID's tcp.
1027 */
1028 droptcb(tcp);
1029 }
Roland McGrath02203312007-06-11 22:06:31 +00001030 continue;
Denys Vlasenko7a8bf062009-01-29 20:38:20 +00001031 } /* if (opendir worked) */
1032 } /* if (-f) */
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001033 if (ptrace_attach_or_seize(tcp->pid) < 0) {
Denys Vlasenko905e8e02013-02-26 12:30:09 +01001034 perror_msg("attach: ptrace(PTRACE_ATTACH, ...)");
Roland McGrath02203312007-06-11 22:06:31 +00001035 droptcb(tcp);
1036 continue;
1037 }
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001038 tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001039 newoutf(tcp);
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001040 if (debug_flag)
Denys Vlasenkof95397a2011-06-24 16:51:16 +02001041 fprintf(stderr, "attach to pid %d (main) succeeded\n", tcp->pid);
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001042
1043 if (daemonized_tracer) {
1044 /*
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001045 * Make parent go away.
1046 * Also makes grandparent's wait() unblock.
1047 */
1048 kill(getppid(), SIGKILL);
1049 }
1050
Roland McGrath02203312007-06-11 22:06:31 +00001051 if (!qflag)
1052 fprintf(stderr,
Denys Vlasenko9c3861d2012-03-16 15:21:49 +01001053 "Process %u attached\n",
Roland McGrath02203312007-06-11 22:06:31 +00001054 tcp->pid);
Denys Vlasenkof95397a2011-06-24 16:51:16 +02001055 } /* for each tcbtab[] */
Roland McGrath02203312007-06-11 22:06:31 +00001056
Denys Vlasenko44f87ef2011-08-17 15:18:21 +02001057 ret:
Roland McGrath02203312007-06-11 22:06:31 +00001058 if (interactive)
1059 sigprocmask(SIG_SETMASK, &empty_set, NULL);
1060}
1061
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001062/* Stack-o-phobic exec helper, in the hope to work around
1063 * NOMMU + "daemonized tracer" difficulty.
1064 */
1065struct exec_params {
1066 int fd_to_close;
1067 uid_t run_euid;
1068 gid_t run_egid;
1069 char **argv;
1070 char *pathname;
1071};
1072static struct exec_params params_for_tracee;
1073static void __attribute__ ((noinline, noreturn))
1074exec_or_die(void)
1075{
1076 struct exec_params *params = &params_for_tracee;
1077
1078 if (params->fd_to_close >= 0)
1079 close(params->fd_to_close);
1080 if (!daemonized_tracer && !use_seize) {
1081 if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) < 0) {
1082 perror_msg_and_die("ptrace(PTRACE_TRACEME, ...)");
1083 }
1084 }
1085
1086 if (username != NULL) {
1087 /*
1088 * It is important to set groups before we
1089 * lose privileges on setuid.
1090 */
1091 if (initgroups(username, run_gid) < 0) {
1092 perror_msg_and_die("initgroups");
1093 }
1094 if (setregid(run_gid, params->run_egid) < 0) {
1095 perror_msg_and_die("setregid");
1096 }
1097 if (setreuid(run_uid, params->run_euid) < 0) {
1098 perror_msg_and_die("setreuid");
1099 }
1100 }
1101 else if (geteuid() != 0)
1102 if (setreuid(run_uid, run_uid) < 0) {
1103 perror_msg_and_die("setreuid");
1104 }
1105
1106 if (!daemonized_tracer) {
1107 /*
1108 * Induce a ptrace stop. Tracer (our parent)
1109 * will resume us with PTRACE_SYSCALL and display
1110 * the immediately following execve syscall.
1111 * Can't do this on NOMMU systems, we are after
1112 * vfork: parent is blocked, stopping would deadlock.
1113 */
1114 if (!NOMMU_SYSTEM)
1115 kill(getpid(), SIGSTOP);
1116 } else {
1117 alarm(3);
1118 /* we depend on SIGCHLD set to SIG_DFL by init code */
1119 /* if it happens to be SIG_IGN'ed, wait won't block */
1120 wait(NULL);
1121 alarm(0);
1122 }
1123
1124 execv(params->pathname, params->argv);
1125 perror_msg_and_die("exec");
1126}
1127
Roland McGrath02203312007-06-11 22:06:31 +00001128static void
Denys Vlasenko12014262011-05-30 14:00:14 +02001129startup_child(char **argv)
Roland McGrath02203312007-06-11 22:06:31 +00001130{
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001131 struct_stat statbuf;
Roland McGrath02203312007-06-11 22:06:31 +00001132 const char *filename;
1133 char pathname[MAXPATHLEN];
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001134 int pid;
Roland McGrath02203312007-06-11 22:06:31 +00001135 struct tcb *tcp;
1136
1137 filename = argv[0];
1138 if (strchr(filename, '/')) {
1139 if (strlen(filename) > sizeof pathname - 1) {
1140 errno = ENAMETOOLONG;
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001141 perror_msg_and_die("exec");
Roland McGrath02203312007-06-11 22:06:31 +00001142 }
1143 strcpy(pathname, filename);
1144 }
1145#ifdef USE_DEBUGGING_EXEC
1146 /*
1147 * Debuggers customarily check the current directory
1148 * first regardless of the path but doing that gives
1149 * security geeks a panic attack.
1150 */
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001151 else if (stat_file(filename, &statbuf) == 0)
Roland McGrath02203312007-06-11 22:06:31 +00001152 strcpy(pathname, filename);
1153#endif /* USE_DEBUGGING_EXEC */
1154 else {
Dmitry V. Levin30145dd2010-09-06 22:08:24 +00001155 const char *path;
Roland McGrath02203312007-06-11 22:06:31 +00001156 int m, n, len;
1157
1158 for (path = getenv("PATH"); path && *path; path += m) {
Denys Vlasenko4f3df072012-01-29 22:38:35 +01001159 const char *colon = strchr(path, ':');
1160 if (colon) {
1161 n = colon - path;
Roland McGrath02203312007-06-11 22:06:31 +00001162 m = n + 1;
1163 }
1164 else
1165 m = n = strlen(path);
1166 if (n == 0) {
1167 if (!getcwd(pathname, MAXPATHLEN))
1168 continue;
1169 len = strlen(pathname);
1170 }
1171 else if (n > sizeof pathname - 1)
1172 continue;
1173 else {
1174 strncpy(pathname, path, n);
1175 len = n;
1176 }
1177 if (len && pathname[len - 1] != '/')
1178 pathname[len++] = '/';
1179 strcpy(pathname + len, filename);
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001180 if (stat_file(pathname, &statbuf) == 0 &&
Roland McGrath02203312007-06-11 22:06:31 +00001181 /* Accept only regular files
1182 with some execute bits set.
1183 XXX not perfect, might still fail */
1184 S_ISREG(statbuf.st_mode) &&
1185 (statbuf.st_mode & 0111))
1186 break;
1187 }
1188 }
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00001189 if (stat_file(pathname, &statbuf) < 0) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001190 perror_msg_and_die("Can't stat '%s'", filename);
Roland McGrath02203312007-06-11 22:06:31 +00001191 }
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001192
1193 params_for_tracee.fd_to_close = (shared_log != stderr) ? fileno(shared_log) : -1;
1194 params_for_tracee.run_euid = (statbuf.st_mode & S_ISUID) ? statbuf.st_uid : run_uid;
1195 params_for_tracee.run_egid = (statbuf.st_mode & S_ISGID) ? statbuf.st_gid : run_gid;
1196 params_for_tracee.argv = argv;
1197 /*
1198 * On NOMMU, can be safely freed only after execve in tracee.
1199 * It's hard to know when that happens, so we just leak it.
1200 */
Denys Vlasenko05f32512013-02-26 12:00:34 +01001201 params_for_tracee.pathname = NOMMU_SYSTEM ? strdup(pathname) : pathname;
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001202
Dmitry V. Levin882478a2013-05-13 18:43:28 +00001203#if defined HAVE_PRCTL && defined PR_SET_PTRACER && defined PR_SET_PTRACER_ANY
1204 if (daemonized_tracer)
1205 prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY);
1206#endif
1207
Denys Vlasenkoe8681c92013-06-26 14:27:11 +02001208 pid = fork();
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001209 if (pid < 0) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001210 perror_msg_and_die("fork");
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001211 }
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001212 if ((pid != 0 && daemonized_tracer)
1213 || (pid == 0 && !daemonized_tracer)
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001214 ) {
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001215 /* We are to become the tracee. Two cases:
1216 * -D: we are parent
1217 * not -D: we are child
1218 */
1219 exec_or_die();
Roland McGrath02203312007-06-11 22:06:31 +00001220 }
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001221
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001222 /* We are the tracer */
Denys Vlasenko75422762011-05-27 14:36:01 +02001223
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001224 if (!daemonized_tracer) {
Denys Vlasenkoe8681c92013-06-26 14:27:11 +02001225 strace_child = pid;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001226 if (!use_seize) {
1227 /* child did PTRACE_TRACEME, nothing to do in parent */
1228 } else {
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001229 if (!NOMMU_SYSTEM) {
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001230 /* Wait until child stopped itself */
1231 int status;
1232 while (waitpid(pid, &status, WSTOPPED) < 0) {
1233 if (errno == EINTR)
1234 continue;
1235 perror_msg_and_die("waitpid");
1236 }
1237 if (!WIFSTOPPED(status) || WSTOPSIG(status) != SIGSTOP) {
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001238 kill_save_errno(pid, SIGKILL);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001239 perror_msg_and_die("Unexpected wait status %x", status);
1240 }
1241 }
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001242 /* Else: NOMMU case, we have no way to sync.
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001243 * Just attach to it as soon as possible.
1244 * This means that we may miss a few first syscalls...
1245 */
1246
1247 if (ptrace_attach_or_seize(pid)) {
Denys Vlasenko75fe85c2012-03-09 15:15:24 +01001248 kill_save_errno(pid, SIGKILL);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001249 perror_msg_and_die("Can't attach to %d", pid);
1250 }
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001251 if (!NOMMU_SYSTEM)
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001252 kill(pid, SIGCONT);
1253 }
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001254 tcp = alloctcb(pid);
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001255 if (!NOMMU_SYSTEM)
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001256 tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
Denys Vlasenkof88837a2011-09-05 14:05:46 +02001257 else
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001258 tcp->flags |= TCB_ATTACHED | TCB_STARTUP;
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001259 newoutf(tcp);
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001260 }
1261 else {
Denys Vlasenko05f32512013-02-26 12:00:34 +01001262 /* With -D, we are *child* here, IOW: different pid. Fetch it: */
Denys Vlasenko2e968c02011-09-01 10:23:09 +02001263 strace_tracer_pid = getpid();
1264 /* The tracee is our parent: */
1265 pid = getppid();
Denys Vlasenkof2025022012-03-09 15:29:45 +01001266 alloctcb(pid);
1267 /* attaching will be done later, by startup_attach */
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001268 /* note: we don't do newoutf(tcp) here either! */
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001269
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001270 /* NOMMU BUG! -D mode is active, we (child) return,
1271 * and we will scribble over parent's stack!
1272 * When parent later unpauses, it segfaults.
1273 *
1274 * We work around it
1275 * (1) by declaring exec_or_die() NORETURN,
1276 * hopefully compiler will just jump to it
1277 * instead of call (won't push anything to stack),
1278 * (2) by trying very hard in exec_or_die()
1279 * to not use any stack,
1280 * (3) having a really big (MAXPATHLEN) stack object
1281 * in this function, which creates a "buffer" between
1282 * child's and parent's stack pointers.
1283 * This may save us if (1) and (2) failed
1284 * and compiler decided to use stack in exec_or_die() anyway
1285 * (happens on i386 because of stack parameter passing).
Denys Vlasenko05f32512013-02-26 12:00:34 +01001286 *
1287 * A cleaner solution is to use makecontext + setcontext
1288 * to create a genuine separate stack and execute on it.
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001289 */
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001290 }
Roland McGrath02203312007-06-11 22:06:31 +00001291}
1292
Wang Chaob13c0de2010-11-12 17:25:19 +08001293/*
Dmitry V. Levinb1467442010-12-02 20:56:43 +00001294 * Test whether the kernel support PTRACE_O_TRACECLONE et al options.
Wang Chaob13c0de2010-11-12 17:25:19 +08001295 * First fork a new child, call ptrace with PTRACE_SETOPTIONS on it,
Dmitry V. Levinb1467442010-12-02 20:56:43 +00001296 * and then see which options are supported by the kernel.
Wang Chaob13c0de2010-11-12 17:25:19 +08001297 */
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001298static int
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001299test_ptrace_setoptions_followfork(void)
Wang Chaob13c0de2010-11-12 17:25:19 +08001300{
Dmitry V. Levin2fabd0e2011-02-19 21:33:50 +00001301 int pid, expected_grandchild = 0, found_grandchild = 0;
1302 const unsigned int test_options = PTRACE_O_TRACECLONE |
1303 PTRACE_O_TRACEFORK |
1304 PTRACE_O_TRACEVFORK;
Wang Chaob13c0de2010-11-12 17:25:19 +08001305
Denys Vlasenko05f32512013-02-26 12:00:34 +01001306 /* Need fork for test. NOMMU has no forks */
1307 if (NOMMU_SYSTEM)
1308 goto worked; /* be bold, and pretend that test succeeded */
1309
Denys Vlasenko5d645812011-08-20 12:48:18 +02001310 pid = fork();
1311 if (pid < 0)
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001312 perror_msg_and_die("fork");
Denys Vlasenko5d645812011-08-20 12:48:18 +02001313 if (pid == 0) {
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001314 pid = getpid();
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001315 if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) < 0)
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001316 perror_msg_and_die("%s: PTRACE_TRACEME doesn't work",
1317 __func__);
Denys Vlasenko4c65c442012-03-08 11:54:10 +01001318 kill_save_errno(pid, SIGSTOP);
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001319 if (fork() < 0)
1320 perror_msg_and_die("fork");
1321 _exit(0);
Wang Chaob13c0de2010-11-12 17:25:19 +08001322 }
Dmitry V. Levinb1467442010-12-02 20:56:43 +00001323
1324 while (1) {
1325 int status, tracee_pid;
1326
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001327 errno = 0;
Dmitry V. Levinb1467442010-12-02 20:56:43 +00001328 tracee_pid = wait(&status);
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001329 if (tracee_pid <= 0) {
Dmitry V. Levinb1467442010-12-02 20:56:43 +00001330 if (errno == EINTR)
1331 continue;
Denys Vlasenko4c65c442012-03-08 11:54:10 +01001332 if (errno == ECHILD)
Dmitry V. Levinb1467442010-12-02 20:56:43 +00001333 break;
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001334 kill_save_errno(pid, SIGKILL);
1335 perror_msg_and_die("%s: unexpected wait result %d",
1336 __func__, tracee_pid);
1337 }
1338 if (WIFEXITED(status)) {
1339 if (WEXITSTATUS(status)) {
1340 if (tracee_pid != pid)
1341 kill_save_errno(pid, SIGKILL);
1342 error_msg_and_die("%s: unexpected exit status %u",
1343 __func__, WEXITSTATUS(status));
1344 }
1345 continue;
1346 }
1347 if (WIFSIGNALED(status)) {
1348 if (tracee_pid != pid)
1349 kill_save_errno(pid, SIGKILL);
1350 error_msg_and_die("%s: unexpected signal %u",
1351 __func__, WTERMSIG(status));
1352 }
1353 if (!WIFSTOPPED(status)) {
1354 if (tracee_pid != pid)
1355 kill_save_errno(tracee_pid, SIGKILL);
Denys Vlasenko4c65c442012-03-08 11:54:10 +01001356 kill_save_errno(pid, SIGKILL);
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001357 error_msg_and_die("%s: unexpected wait status %x",
1358 __func__, status);
Dmitry V. Levinb1467442010-12-02 20:56:43 +00001359 }
1360 if (tracee_pid != pid) {
Dmitry V. Levin2fabd0e2011-02-19 21:33:50 +00001361 found_grandchild = tracee_pid;
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001362 if (ptrace(PTRACE_CONT, tracee_pid, 0, 0) < 0) {
1363 kill_save_errno(tracee_pid, SIGKILL);
1364 kill_save_errno(pid, SIGKILL);
1365 perror_msg_and_die("PTRACE_CONT doesn't work");
Wang Chaob13c0de2010-11-12 17:25:19 +08001366 }
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001367 continue;
1368 }
1369 switch (WSTOPSIG(status)) {
1370 case SIGSTOP:
1371 if (ptrace(PTRACE_SETOPTIONS, pid, 0, test_options) < 0
1372 && errno != EINVAL && errno != EIO)
1373 perror_msg("PTRACE_SETOPTIONS");
1374 break;
1375 case SIGTRAP:
1376 if (status >> 16 == PTRACE_EVENT_FORK) {
1377 long msg = 0;
1378
1379 if (ptrace(PTRACE_GETEVENTMSG, pid,
1380 NULL, (long) &msg) == 0)
1381 expected_grandchild = msg;
1382 }
1383 break;
1384 }
1385 if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) {
1386 kill_save_errno(pid, SIGKILL);
1387 perror_msg_and_die("PTRACE_SYSCALL doesn't work");
Wang Chaob13c0de2010-11-12 17:25:19 +08001388 }
1389 }
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001390 if (expected_grandchild && expected_grandchild == found_grandchild) {
Denys Vlasenko05f32512013-02-26 12:00:34 +01001391 worked:
Denys Vlasenkof44cce42011-06-21 14:34:10 +02001392 ptrace_setoptions |= test_options;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001393 if (debug_flag)
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001394 fprintf(stderr, "ptrace_setoptions = %#x\n",
1395 ptrace_setoptions);
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001396 return 0;
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001397 }
1398 error_msg("Test for PTRACE_O_TRACECLONE failed, "
1399 "giving up using this feature.");
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001400 return 1;
Wang Chaob13c0de2010-11-12 17:25:19 +08001401}
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001402
1403/*
1404 * Test whether the kernel support PTRACE_O_TRACESYSGOOD.
1405 * First fork a new child, call ptrace(PTRACE_SETOPTIONS) on it,
1406 * and then see whether it will stop with (SIGTRAP | 0x80).
1407 *
1408 * Use of this option enables correct handling of user-generated SIGTRAPs,
1409 * and SIGTRAPs generated by special instructions such as int3 on x86:
1410 * _start: .globl _start
1411 * int3
1412 * movl $42, %ebx
1413 * movl $1, %eax
1414 * int $0x80
1415 * (compile with: "gcc -nostartfiles -nostdlib -o int3 int3.S")
1416 */
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001417static int
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001418test_ptrace_setoptions_for_all(void)
1419{
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001420 const unsigned int test_options = PTRACE_O_TRACESYSGOOD |
1421 PTRACE_O_TRACEEXEC;
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001422 int pid;
1423 int it_worked = 0;
1424
Denys Vlasenko05f32512013-02-26 12:00:34 +01001425 /* Need fork for test. NOMMU has no forks */
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001426 if (NOMMU_SYSTEM)
Denys Vlasenko05f32512013-02-26 12:00:34 +01001427 goto worked; /* be bold, and pretend that test succeeded */
Mike Frysinger7ff5ed92012-04-05 01:52:25 -04001428
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001429 pid = fork();
1430 if (pid < 0)
Denys Vlasenko75422762011-05-27 14:36:01 +02001431 perror_msg_and_die("fork");
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001432
1433 if (pid == 0) {
1434 pid = getpid();
1435 if (ptrace(PTRACE_TRACEME, 0L, 0L, 0L) < 0)
Denys Vlasenko75422762011-05-27 14:36:01 +02001436 /* Note: exits with exitcode 1 */
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001437 perror_msg_and_die("%s: PTRACE_TRACEME doesn't work",
1438 __func__);
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001439 kill(pid, SIGSTOP);
1440 _exit(0); /* parent should see entry into this syscall */
1441 }
1442
1443 while (1) {
1444 int status, tracee_pid;
1445
1446 errno = 0;
1447 tracee_pid = wait(&status);
1448 if (tracee_pid <= 0) {
1449 if (errno == EINTR)
1450 continue;
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001451 kill_save_errno(pid, SIGKILL);
1452 perror_msg_and_die("%s: unexpected wait result %d",
1453 __func__, tracee_pid);
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001454 }
Denys Vlasenko75422762011-05-27 14:36:01 +02001455 if (WIFEXITED(status)) {
1456 if (WEXITSTATUS(status) == 0)
1457 break;
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001458 error_msg_and_die("%s: unexpected exit status %u",
1459 __func__, WEXITSTATUS(status));
1460 }
1461 if (WIFSIGNALED(status)) {
1462 error_msg_and_die("%s: unexpected signal %u",
1463 __func__, WTERMSIG(status));
Denys Vlasenko75422762011-05-27 14:36:01 +02001464 }
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001465 if (!WIFSTOPPED(status)) {
1466 kill(pid, SIGKILL);
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001467 error_msg_and_die("%s: unexpected wait status %x",
1468 __func__, status);
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001469 }
1470 if (WSTOPSIG(status) == SIGSTOP) {
1471 /*
1472 * We don't check "options aren't accepted" error.
1473 * If it happens, we'll never get (SIGTRAP | 0x80),
1474 * and thus will decide to not use the option.
1475 * IOW: the outcome of the test will be correct.
1476 */
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001477 if (ptrace(PTRACE_SETOPTIONS, pid, 0L, test_options) < 0
1478 && errno != EINVAL && errno != EIO)
1479 perror_msg("PTRACE_SETOPTIONS");
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001480 }
1481 if (WSTOPSIG(status) == (SIGTRAP | 0x80)) {
1482 it_worked = 1;
1483 }
1484 if (ptrace(PTRACE_SYSCALL, pid, 0L, 0L) < 0) {
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001485 kill_save_errno(pid, SIGKILL);
Denys Vlasenko75422762011-05-27 14:36:01 +02001486 perror_msg_and_die("PTRACE_SYSCALL doesn't work");
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001487 }
1488 }
1489
1490 if (it_worked) {
Denys Vlasenko05f32512013-02-26 12:00:34 +01001491 worked:
Denys Vlasenko75422762011-05-27 14:36:01 +02001492 syscall_trap_sig = (SIGTRAP | 0x80);
Denys Vlasenkof44cce42011-06-21 14:34:10 +02001493 ptrace_setoptions |= test_options;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001494 if (debug_flag)
Denys Vlasenkof44cce42011-06-21 14:34:10 +02001495 fprintf(stderr, "ptrace_setoptions = %#x\n",
1496 ptrace_setoptions);
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001497 return 0;
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001498 }
1499
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001500 error_msg("Test for PTRACE_O_TRACESYSGOOD failed, "
1501 "giving up using this feature.");
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001502 return 1;
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02001503}
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001504
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001505#if USE_SEIZE
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001506static void
1507test_ptrace_seize(void)
1508{
1509 int pid;
1510
Denys Vlasenko05f32512013-02-26 12:00:34 +01001511 /* Need fork for test. NOMMU has no forks */
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001512 if (NOMMU_SYSTEM) {
1513 post_attach_sigstop = 0; /* this sets use_seize to 1 */
1514 return;
1515 }
1516
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001517 pid = fork();
1518 if (pid < 0)
1519 perror_msg_and_die("fork");
1520
1521 if (pid == 0) {
1522 pause();
1523 _exit(0);
1524 }
1525
1526 /* PTRACE_SEIZE, unlike ATTACH, doesn't force tracee to trap. After
1527 * attaching tracee continues to run unless a trap condition occurs.
1528 * PTRACE_SEIZE doesn't affect signal or group stop state.
1529 */
Denys Vlasenko26bc0602012-07-10 16:36:32 +02001530 if (ptrace(PTRACE_SEIZE, pid, 0, 0) == 0) {
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001531 post_attach_sigstop = 0; /* this sets use_seize to 1 */
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001532 } else if (debug_flag) {
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001533 fprintf(stderr, "PTRACE_SEIZE doesn't work\n");
1534 }
1535
1536 kill(pid, SIGKILL);
1537
1538 while (1) {
1539 int status, tracee_pid;
1540
1541 errno = 0;
1542 tracee_pid = waitpid(pid, &status, 0);
1543 if (tracee_pid <= 0) {
1544 if (errno == EINTR)
1545 continue;
1546 perror_msg_and_die("%s: unexpected wait result %d",
1547 __func__, tracee_pid);
1548 }
1549 if (WIFSIGNALED(status)) {
1550 return;
1551 }
1552 error_msg_and_die("%s: unexpected wait status %x",
1553 __func__, status);
1554 }
1555}
Denys Vlasenko978fbc92012-09-13 10:28:43 +02001556#else /* !USE_SEIZE */
1557# define test_ptrace_seize() ((void)0)
1558#endif
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001559
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001560static unsigned
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001561get_os_release(void)
1562{
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001563 unsigned rel;
1564 const char *p;
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001565 struct utsname u;
1566 if (uname(&u) < 0)
1567 perror_msg_and_die("uname");
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001568 /* u.release has this form: "3.2.9[-some-garbage]" */
1569 rel = 0;
1570 p = u.release;
1571 for (;;) {
1572 if (!(*p >= '0' && *p <= '9'))
1573 error_msg_and_die("Bad OS release string: '%s'", u.release);
1574 /* Note: this open-codes KERNEL_VERSION(): */
1575 rel = (rel << 8) | atoi(p);
1576 if (rel >= KERNEL_VERSION(1,0,0))
1577 break;
1578 while (*p >= '0' && *p <= '9')
1579 p++;
Dmitry V. Levin0dbc80d2012-05-14 23:42:10 +00001580 if (*p != '.') {
1581 if (rel >= KERNEL_VERSION(0,1,0)) {
1582 /* "X.Y-something" means "X.Y.0" */
1583 rel <<= 8;
1584 break;
1585 }
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001586 error_msg_and_die("Bad OS release string: '%s'", u.release);
Dmitry V. Levin0dbc80d2012-05-14 23:42:10 +00001587 }
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001588 p++;
1589 }
1590 return rel;
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001591}
1592
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01001593/*
1594 * Initialization part of main() was eating much stack (~0.5k),
1595 * which was unused after init.
1596 * We can reuse it if we move init code into a separate function.
1597 *
1598 * Don't want main() to inline us and defeat the reason
1599 * we have a separate function.
1600 */
1601static void __attribute__ ((noinline))
1602init(int argc, char *argv[])
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001603{
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001604 struct tcb *tcp;
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001605 int c, i;
Dmitry V. Levin06350db2008-07-25 15:42:34 +00001606 int optF = 0;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001607 struct sigaction sa;
1608
Dmitry V. Levin08b623e2007-10-08 21:04:41 +00001609 progname = argv[0] ? argv[0] : "strace";
1610
Denys Vlasenkoa5090542012-03-15 17:27:49 +01001611 /* Make sure SIGCHLD has the default action so that waitpid
1612 definitely works without losing track of children. The user
1613 should not have given us a bogus state to inherit, but he might
1614 have. Arguably we should detect SIG_IGN here and pass it on
1615 to children, but probably noone really needs that. */
1616 signal(SIGCHLD, SIG_DFL);
1617
Denys Vlasenko75422762011-05-27 14:36:01 +02001618 strace_tracer_pid = getpid();
1619
Denys Vlasenko6e0bfd12012-03-15 14:36:28 +01001620 os_release = get_os_release();
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001621
Roland McGrathee9d4352002-12-18 04:16:10 +00001622 /* Allocate the initial tcbtab. */
1623 tcbtabsize = argc; /* Surely enough for all -p args. */
Denys Vlasenko4f12af22011-06-23 13:16:23 +02001624 tcbtab = calloc(tcbtabsize, sizeof(tcbtab[0]));
Denys Vlasenko1d46ba52011-08-31 14:00:02 +02001625 if (!tcbtab)
1626 die_out_of_memory();
Denys Vlasenko4f12af22011-06-23 13:16:23 +02001627 tcp = calloc(tcbtabsize, sizeof(*tcp));
Denys Vlasenko1d46ba52011-08-31 14:00:02 +02001628 if (!tcp)
1629 die_out_of_memory();
Denys Vlasenko4f12af22011-06-23 13:16:23 +02001630 for (c = 0; c < tcbtabsize; c++)
1631 tcbtab[c] = tcp++;
Roland McGrathee9d4352002-12-18 04:16:10 +00001632
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001633 shared_log = stderr;
Roland McGrath138c6a32006-01-12 09:50:49 +00001634 set_sortby(DEFAULT_SORTBY);
1635 set_personality(DEFAULT_PERSONALITY);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001636 qualify("trace=all");
1637 qualify("abbrev=all");
1638 qualify("verbose=all");
Denys Vlasenko74ec14f2013-02-21 16:13:47 +01001639#if DEFAULT_QUAL_FLAGS != (QUAL_TRACE | QUAL_ABBREV | QUAL_VERBOSE)
1640# error Bug in DEFAULT_QUAL_FLAGS
1641#endif
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001642 qualify("signal=all");
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001643 while ((c = getopt(argc, argv,
Denys Vlasenko22efaf02013-02-27 12:15:19 +01001644 "+b:cCdfFhiqrtTvVxyz"
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001645 "D"
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001646 "a:e:o:O:p:s:S:u:E:P:I:")) != EOF) {
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001647 switch (c) {
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001648 case 'b':
Denys Vlasenko22efaf02013-02-27 12:15:19 +01001649 if (strcmp(optarg, "execve") != 0)
1650 error_msg_and_die("Syscall '%s' for -b isn't supported",
1651 optarg);
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001652 detach_on_execve = 1;
1653 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001654 case 'c':
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00001655 if (cflag == CFLAG_BOTH) {
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +02001656 error_msg_and_die("-c and -C are mutually exclusive");
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00001657 }
1658 cflag = CFLAG_ONLY_STATS;
1659 break;
1660 case 'C':
1661 if (cflag == CFLAG_ONLY_STATS) {
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +02001662 error_msg_and_die("-c and -C are mutually exclusive");
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00001663 }
1664 cflag = CFLAG_BOTH;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001665 break;
1666 case 'd':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001667 debug_flag = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001668 break;
Denys Vlasenkoecfe2f12008-12-30 20:51:30 +00001669 case 'D':
1670 daemonized_tracer = 1;
1671 break;
Roland McGrath41c48222008-07-18 00:25:10 +00001672 case 'F':
Dmitry V. Levin06350db2008-07-25 15:42:34 +00001673 optF = 1;
1674 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001675 case 'f':
1676 followfork++;
1677 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001678 case 'h':
1679 usage(stdout, 0);
1680 break;
1681 case 'i':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001682 iflag = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001683 break;
1684 case 'q':
Daniel P. Berrange01997cf2013-05-13 11:30:55 +01001685 qflag++;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001686 break;
1687 case 'r':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001688 rflag = 1;
1689 /* fall through to tflag++ */
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001690 case 't':
1691 tflag++;
1692 break;
1693 case 'T':
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001694 Tflag = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001695 break;
1696 case 'x':
1697 xflag++;
1698 break;
Grant Edwards8a082772011-04-07 20:25:40 +00001699 case 'y':
1700 show_fd_path = 1;
1701 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001702 case 'v':
1703 qualify("abbrev=none");
1704 break;
1705 case 'V':
Roland McGrath9c9a2532003-02-20 02:56:29 +00001706 printf("%s -- version %s\n", PACKAGE_NAME, VERSION);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001707 exit(0);
1708 break;
Michal Ludvig17f8fb32002-11-06 13:17:21 +00001709 case 'z':
1710 not_failing_only = 1;
1711 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001712 case 'a':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001713 acolumn = string_to_uint(optarg);
Denys Vlasenko102ec492011-08-25 01:27:59 +02001714 if (acolumn < 0)
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001715 error_opt_arg(c, optarg);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001716 break;
1717 case 'e':
1718 qualify(optarg);
1719 break;
1720 case 'o':
1721 outfname = strdup(optarg);
1722 break;
1723 case 'O':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001724 i = string_to_uint(optarg);
1725 if (i < 0)
1726 error_opt_arg(c, optarg);
1727 set_overhead(i);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001728 break;
1729 case 'p':
Denys Vlasenkoe8172b72012-03-09 13:01:04 +01001730 process_opt_p_list(optarg);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001731 break;
Grant Edwards8a082772011-04-07 20:25:40 +00001732 case 'P':
Denys Vlasenko7239dbc2013-03-05 15:46:34 +01001733 pathtrace_select(optarg);
Grant Edwards8a082772011-04-07 20:25:40 +00001734 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001735 case 's':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001736 i = string_to_uint(optarg);
1737 if (i < 0)
1738 error_opt_arg(c, optarg);
1739 max_strlen = i;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001740 break;
1741 case 'S':
1742 set_sortby(optarg);
1743 break;
1744 case 'u':
1745 username = strdup(optarg);
1746 break;
Roland McGrathde6e5332003-01-24 04:31:23 +00001747 case 'E':
Denys Vlasenko1d46ba52011-08-31 14:00:02 +02001748 if (putenv(optarg) < 0)
1749 die_out_of_memory();
Roland McGrathde6e5332003-01-24 04:31:23 +00001750 break;
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001751 case 'I':
Dmitry V. Levinccee1692012-03-25 21:49:48 +00001752 opt_intr = string_to_uint(optarg);
1753 if (opt_intr <= 0 || opt_intr >= NUM_INTR_OPTS)
1754 error_opt_arg(c, optarg);
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001755 break;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001756 default:
1757 usage(stderr, 1);
1758 break;
1759 }
1760 }
Denys Vlasenko837399a2012-01-24 11:37:03 +01001761 argv += optind;
1762 /* argc -= optind; - no need, argc is not used below */
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001763
Denys Vlasenko102ec492011-08-25 01:27:59 +02001764 acolumn_spaces = malloc(acolumn + 1);
1765 if (!acolumn_spaces)
Denys Vlasenko1d46ba52011-08-31 14:00:02 +02001766 die_out_of_memory();
Denys Vlasenko102ec492011-08-25 01:27:59 +02001767 memset(acolumn_spaces, ' ', acolumn);
1768 acolumn_spaces[acolumn] = '\0';
1769
Denys Vlasenko837399a2012-01-24 11:37:03 +01001770 /* Must have PROG [ARGS], or -p PID. Not both. */
Denys Vlasenkofd883382012-03-09 13:03:41 +01001771 if (!argv[0] == !nprocs)
Roland McGrathce0d1542003-11-11 21:24:23 +00001772 usage(stderr, 1);
1773
Denys Vlasenkofd883382012-03-09 13:03:41 +01001774 if (nprocs != 0 && daemonized_tracer) {
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +02001775 error_msg_and_die("-D and -p are mutually exclusive");
Wang Chaod322a4b2010-08-05 14:30:11 +08001776 }
1777
Dmitry V. Levin06350db2008-07-25 15:42:34 +00001778 if (!followfork)
1779 followfork = optF;
1780
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001781 if (followfork >= 2 && cflag) {
Denys Vlasenkoc5ccfa42012-03-26 13:10:50 +02001782 error_msg_and_die("(-c or -C) and -ff are mutually exclusive");
Roland McGrathcb9def62006-04-25 07:48:03 +00001783 }
1784
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001785 /* See if they want to run as another user. */
1786 if (username != NULL) {
1787 struct passwd *pent;
1788
1789 if (getuid() != 0 || geteuid() != 0) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001790 error_msg_and_die("You must be root to use the -u option");
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001791 }
Denys Vlasenko5d645812011-08-20 12:48:18 +02001792 pent = getpwnam(username);
1793 if (pent == NULL) {
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001794 error_msg_and_die("Cannot find user '%s'", username);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001795 }
1796 run_uid = pent->pw_uid;
1797 run_gid = pent->pw_gid;
1798 }
1799 else {
1800 run_uid = getuid();
1801 run_gid = getgid();
1802 }
1803
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001804 /*
1805 * On any reasonably recent Linux kernel (circa about 2.5.46)
1806 * need_fork_exec_workarounds should stay 0 after these tests:
1807 */
1808 /*need_fork_exec_workarounds = 0; - already is */
Dmitry V. Levin04f8b482011-08-16 18:57:29 +00001809 if (followfork)
Denys Vlasenko8d4ca0c2013-02-06 13:18:42 +01001810 need_fork_exec_workarounds = test_ptrace_setoptions_followfork();
1811 need_fork_exec_workarounds |= test_ptrace_setoptions_for_all();
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001812 test_ptrace_seize();
Dmitry V. Levin8044bc12010-12-07 12:50:49 +00001813
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001814 /* Check if they want to redirect the output. */
1815 if (outfname) {
Roland McGrath37b9a662003-11-07 02:26:54 +00001816 /* See if they want to pipe the output. */
1817 if (outfname[0] == '|' || outfname[0] == '!') {
1818 /*
1819 * We can't do the <outfname>.PID funny business
1820 * when using popen, so prohibit it.
1821 */
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001822 if (followfork >= 2)
Denys Vlasenko7dd23382011-06-22 13:03:56 +02001823 error_msg_and_die("Piping the output and -ff are mutually exclusive");
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001824 shared_log = strace_popen(outfname + 1);
Roland McGrath37b9a662003-11-07 02:26:54 +00001825 }
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001826 else if (followfork < 2)
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001827 shared_log = strace_fopen(outfname);
Denys Vlasenko328bf252012-03-12 23:34:13 +01001828 } else {
1829 /* -ff without -o FILE is the same as single -f */
Denys Vlasenko3db3b262012-03-16 15:15:14 +01001830 if (followfork >= 2)
Denys Vlasenko328bf252012-03-12 23:34:13 +01001831 followfork = 1;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001832 }
1833
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001834 if (!outfname || outfname[0] == '|' || outfname[0] == '!') {
Denys Vlasenkoa677da52012-01-24 11:31:51 +01001835 char *buf = malloc(BUFSIZ);
1836 if (!buf)
1837 die_out_of_memory();
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001838 setvbuf(shared_log, buf, _IOLBF, BUFSIZ);
Denys Vlasenkocb2ad002011-06-23 13:05:29 +02001839 }
Denys Vlasenko837399a2012-01-24 11:37:03 +01001840 if (outfname && argv[0]) {
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001841 if (!opt_intr)
1842 opt_intr = INTR_NEVER;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001843 qflag = 1;
Roland McGrath36931052003-06-03 01:35:20 +00001844 }
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001845 if (!opt_intr)
1846 opt_intr = INTR_WHILE_WAIT;
Wang Chaob13c0de2010-11-12 17:25:19 +08001847
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001848 /* argv[0] -pPID -oFILE Default interactive setting
1849 * yes 0 0 INTR_WHILE_WAIT
1850 * no 1 0 INTR_WHILE_WAIT
1851 * yes 0 1 INTR_NEVER
1852 * no 1 1 INTR_WHILE_WAIT
Roland McGrath54cc1c82007-11-03 23:34:11 +00001853 */
1854
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01001855 sigemptyset(&empty_set);
1856 sigemptyset(&blocked_set);
1857
Denys Vlasenkof909c8d2013-02-19 16:30:31 +01001858 /* startup_child() must be called before the signal handlers get
1859 * installed below as they are inherited into the spawned process.
1860 * Also we do not need to be protected by them as during interruption
1861 * in the startup_child() mode we kill the spawned process anyway.
1862 */
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001863 if (argv[0]) {
Dmitry V. Levin1d2435b2013-05-14 22:35:46 +00001864 if (!NOMMU_SYSTEM || daemonized_tracer)
1865 hide_log_until_execve = 1;
Denys Vlasenko2a3d2752013-05-14 16:07:46 +02001866 skip_one_b_execve = 1;
Denys Vlasenko837399a2012-01-24 11:37:03 +01001867 startup_child(argv);
Denys Vlasenko61e7aad2012-03-15 13:44:17 +01001868 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001869
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001870 sa.sa_handler = SIG_IGN;
1871 sigemptyset(&sa.sa_mask);
1872 sa.sa_flags = 0;
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001873 sigaction(SIGTTOU, &sa, NULL); /* SIG_IGN */
1874 sigaction(SIGTTIN, &sa, NULL); /* SIG_IGN */
1875 if (opt_intr != INTR_ANYWHERE) {
1876 if (opt_intr == INTR_BLOCK_TSTP_TOO)
1877 sigaction(SIGTSTP, &sa, NULL); /* SIG_IGN */
1878 /*
1879 * In interactive mode (if no -o OUTFILE, or -p PID is used),
1880 * fatal signals are blocked while syscall stop is processed,
1881 * and acted on in between, when waiting for new syscall stops.
1882 * In non-interactive mode, signals are ignored.
1883 */
1884 if (opt_intr == INTR_WHILE_WAIT) {
1885 sigaddset(&blocked_set, SIGHUP);
1886 sigaddset(&blocked_set, SIGINT);
1887 sigaddset(&blocked_set, SIGQUIT);
1888 sigaddset(&blocked_set, SIGPIPE);
1889 sigaddset(&blocked_set, SIGTERM);
1890 sa.sa_handler = interrupt;
Denys Vlasenkob51581e2012-01-29 16:53:03 +01001891 }
1892 /* SIG_IGN, or set handler for these */
1893 sigaction(SIGHUP, &sa, NULL);
1894 sigaction(SIGINT, &sa, NULL);
1895 sigaction(SIGQUIT, &sa, NULL);
1896 sigaction(SIGPIPE, &sa, NULL);
1897 sigaction(SIGTERM, &sa, NULL);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001898 }
Denys Vlasenkofd883382012-03-09 13:03:41 +01001899 if (nprocs != 0 || daemonized_tracer)
Roland McGrath02203312007-06-11 22:06:31 +00001900 startup_attach();
Roland McGrath02203312007-06-11 22:06:31 +00001901
Denys Vlasenkofd883382012-03-09 13:03:41 +01001902 /* Do we want pids printed in our -o OUTFILE?
1903 * -ff: no (every pid has its own file); or
1904 * -f: yes (there can be more pids in the future); or
1905 * -p PID1,PID2: yes (there are already more than one pid)
1906 */
1907 print_pid_pfx = (outfname && followfork < 2 && (followfork == 1 || nprocs > 1));
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001908}
1909
Denys Vlasenkoeebb04d2012-01-27 15:24:48 +01001910static struct tcb *
Roland McGrath54e931f2010-09-14 18:59:20 -07001911pid2tcb(int pid)
1912{
1913 int i;
1914
1915 if (pid <= 0)
1916 return NULL;
1917
1918 for (i = 0; i < tcbtabsize; i++) {
1919 struct tcb *tcp = tcbtab[i];
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001920 if (tcp->pid == pid)
Roland McGrath54e931f2010-09-14 18:59:20 -07001921 return tcp;
1922 }
1923
1924 return NULL;
1925}
1926
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001927static void
Denys Vlasenko12014262011-05-30 14:00:14 +02001928cleanup(void)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001929{
1930 int i;
1931 struct tcb *tcp;
Denys Vlasenko35218842012-01-29 21:17:56 +01001932 int fatal_sig;
1933
1934 /* 'interrupted' is a volatile object, fetch it only once */
1935 fatal_sig = interrupted;
1936 if (!fatal_sig)
1937 fatal_sig = SIGTERM;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001938
Roland McGrathee9d4352002-12-18 04:16:10 +00001939 for (i = 0; i < tcbtabsize; i++) {
1940 tcp = tcbtab[i];
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001941 if (!tcp->pid)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001942 continue;
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01001943 if (debug_flag)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001944 fprintf(stderr,
1945 "cleanup: looking at pid %u\n", tcp->pid);
Denys Vlasenkofadbf662013-06-26 14:14:29 +02001946 if (tcp->pid == strace_child) {
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001947 kill(tcp->pid, SIGCONT);
Denys Vlasenkoa3559252012-01-29 16:43:51 +01001948 kill(tcp->pid, fatal_sig);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001949 }
Denys Vlasenko7de265d2012-03-13 11:44:31 +01001950 detach(tcp);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001951 }
1952 if (cflag)
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01001953 call_summary(shared_log);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001954}
1955
1956static void
Denys Vlasenko12014262011-05-30 14:00:14 +02001957interrupt(int sig)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001958{
Denys Vlasenkoa3559252012-01-29 16:43:51 +01001959 interrupted = sig;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001960}
1961
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02001962static void
Denys Vlasenko12014262011-05-30 14:00:14 +02001963trace(void)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001964{
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001965 struct rusage ru;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001966
Denys Vlasenkod2e1f422013-07-08 11:28:27 +02001967 /* Used to be "while (nprocs != 0)", but in this testcase:
1968 * int main() { _exit(!!fork()); }
1969 * under strace -f, parent sometimes (rarely) manages
1970 * to exit before we see the first stop of the child,
1971 * and we are losing track of it:
1972 * 19923 clone(...) = 19924
1973 * 19923 exit_group(1) = ?
1974 * 19923 +++ exited with 1 +++
1975 * Waiting for ECHILD works better.
Denys Vlasenko7c41ce22013-07-08 13:55:04 +02001976 * (However, if -o|logger is in use, we can't do that.
1977 * Can work around that by double-forking the logger,
1978 * but that loses the ability to wait for its completion on exit.
1979 * Oh well...)
Denys Vlasenkod2e1f422013-07-08 11:28:27 +02001980 */
1981 while (1) {
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001982 int pid;
1983 int wait_errno;
1984 int status, sig;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01001985 int stopped;
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01001986 struct tcb *tcp;
1987 unsigned event;
1988
Denys Vlasenko222713a2009-03-17 14:29:59 +00001989 if (interrupted)
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02001990 return;
Denys Vlasenko725dd422013-06-20 11:06:58 +02001991
Denys Vlasenko7c41ce22013-07-08 13:55:04 +02001992 if (popen_pid != 0 && nprocs == 0)
1993 return;
1994
Roland McGratheb9e2e82009-06-02 16:49:22 -07001995 if (interactive)
1996 sigprocmask(SIG_SETMASK, &empty_set, NULL);
Denys Vlasenko725dd422013-06-20 11:06:58 +02001997 pid = wait4(-1, &status, __WALL, (cflag ? &ru : NULL));
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00001998 wait_errno = errno;
Roland McGratheb9e2e82009-06-02 16:49:22 -07001999 if (interactive)
2000 sigprocmask(SIG_BLOCK, &blocked_set, NULL);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002001
Denys Vlasenko26d1b1e2011-08-15 12:24:14 +02002002 if (pid < 0) {
Denys Vlasenko725dd422013-06-20 11:06:58 +02002003 if (wait_errno == EINTR)
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002004 continue;
Denys Vlasenkod2e1f422013-07-08 11:28:27 +02002005 if (nprocs == 0 && wait_errno == ECHILD)
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02002006 return;
Denys Vlasenkod2e1f422013-07-08 11:28:27 +02002007 /* If nprocs > 0, ECHILD is not expected,
2008 * treat it as any other error here:
2009 */
Denys Vlasenko725dd422013-06-20 11:06:58 +02002010 errno = wait_errno;
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02002011 perror_msg_and_die("wait4(__WALL)");
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002012 }
Denys Vlasenko725dd422013-06-20 11:06:58 +02002013
Dmitry V. Levin10de62b2006-12-13 21:45:31 +00002014 if (pid == popen_pid) {
Denys Vlasenkoc8511f02013-06-26 14:29:19 +02002015 if (!WIFSTOPPED(status))
Denys Vlasenko7dd23382011-06-22 13:03:56 +02002016 popen_pid = 0;
Dmitry V. Levin10de62b2006-12-13 21:45:31 +00002017 continue;
2018 }
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01002019
2020 event = ((unsigned)status >> 16);
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01002021 if (debug_flag) {
Denys Vlasenko1d5f12e2011-06-24 16:41:35 +02002022 char buf[sizeof("WIFEXITED,exitcode=%u") + sizeof(int)*3 /*paranoia:*/ + 16];
Denys Vlasenko1b2bfbc2013-06-21 16:41:50 +02002023 char evbuf[sizeof(",EVENT_VFORK_DONE (%u)") + sizeof(int)*3 /*paranoia:*/ + 16];
Denys Vlasenko1d5f12e2011-06-24 16:41:35 +02002024 strcpy(buf, "???");
2025 if (WIFSIGNALED(status))
2026#ifdef WCOREDUMP
2027 sprintf(buf, "WIFSIGNALED,%ssig=%s",
2028 WCOREDUMP(status) ? "core," : "",
2029 signame(WTERMSIG(status)));
2030#else
2031 sprintf(buf, "WIFSIGNALED,sig=%s",
2032 signame(WTERMSIG(status)));
2033#endif
2034 if (WIFEXITED(status))
2035 sprintf(buf, "WIFEXITED,exitcode=%u", WEXITSTATUS(status));
2036 if (WIFSTOPPED(status))
2037 sprintf(buf, "WIFSTOPPED,sig=%s", signame(WSTOPSIG(status)));
Denys Vlasenko5bd67c82011-08-15 11:36:09 +02002038#ifdef WIFCONTINUED
Denys Vlasenkoc8511f02013-06-26 14:29:19 +02002039 /* Should never be seen */
Denys Vlasenko1d5f12e2011-06-24 16:41:35 +02002040 if (WIFCONTINUED(status))
2041 strcpy(buf, "WIFCONTINUED");
Denys Vlasenko5bd67c82011-08-15 11:36:09 +02002042#endif
Denys Vlasenko67559ad2012-03-13 12:05:27 +01002043 evbuf[0] = '\0';
2044 if (event != 0) {
2045 static const char *const event_names[] = {
2046 [PTRACE_EVENT_CLONE] = "CLONE",
2047 [PTRACE_EVENT_FORK] = "FORK",
2048 [PTRACE_EVENT_VFORK] = "VFORK",
2049 [PTRACE_EVENT_VFORK_DONE] = "VFORK_DONE",
2050 [PTRACE_EVENT_EXEC] = "EXEC",
2051 [PTRACE_EVENT_EXIT] = "EXIT",
Denys Vlasenko4e020c02013-06-21 16:33:56 +02002052 /* [PTRACE_EVENT_STOP (=128)] would make biggish array */
Denys Vlasenko67559ad2012-03-13 12:05:27 +01002053 };
Denys Vlasenko1b2bfbc2013-06-21 16:41:50 +02002054 const char *e = "??";
Denys Vlasenko67559ad2012-03-13 12:05:27 +01002055 if (event < ARRAY_SIZE(event_names))
2056 e = event_names[event];
Denys Vlasenko4e020c02013-06-21 16:33:56 +02002057 else if (event == PTRACE_EVENT_STOP)
2058 e = "STOP";
Denys Vlasenko1b2bfbc2013-06-21 16:41:50 +02002059 sprintf(evbuf, ",EVENT_%s (%u)", e, event);
Denys Vlasenko67559ad2012-03-13 12:05:27 +01002060 }
Denys Vlasenko38eab5d2013-07-02 12:18:22 +02002061 fprintf(stderr, " [wait(0x%06x) = %u] %s%s\n", status, pid, buf, evbuf);
Denys Vlasenko1d5f12e2011-06-24 16:41:35 +02002062 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002063
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01002064 /* Look up 'pid' in our table. */
Denys Vlasenko5d645812011-08-20 12:48:18 +02002065 tcp = pid2tcb(pid);
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01002066
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002067 if (!tcp) {
Denys Vlasenkoc8511f02013-06-26 14:29:19 +02002068 if (!WIFSTOPPED(status)) {
2069 /* This can happen if we inherited
2070 * an unknown child. Example:
2071 * (sleep 1 & exec strace sleep 2)
2072 */
2073 error_msg("Exit of unknown pid %u seen", pid);
2074 continue;
2075 }
Roland McGrath41c48222008-07-18 00:25:10 +00002076 if (followfork) {
Denys Vlasenkoc8511f02013-06-26 14:29:19 +02002077 /* We assume it's a fork/vfork/clone child */
Denys Vlasenko418d66a2009-01-17 01:52:54 +00002078 tcp = alloctcb(pid);
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002079 tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
Denys Vlasenko3db3b262012-03-16 15:15:14 +01002080 newoutf(tcp);
Roland McGrathe85bbfe2003-01-09 06:53:31 +00002081 if (!qflag)
Denys Vlasenko833fb132011-08-17 11:30:56 +02002082 fprintf(stderr, "Process %d attached\n",
Roland McGrathe85bbfe2003-01-09 06:53:31 +00002083 pid);
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002084 } else {
Roland McGrathe85bbfe2003-01-09 06:53:31 +00002085 /* This can happen if a clone call used
Denys Vlasenkoc8511f02013-06-26 14:29:19 +02002086 * CLONE_PTRACE itself.
Denys Vlasenko71d3d292013-06-21 16:19:46 +02002087 */
Denys Vlasenkoc8511f02013-06-26 14:29:19 +02002088 ptrace(PTRACE_CONT, pid, (char *) 0, 0);
2089 error_msg("Stop of unknown pid %u seen, PTRACE_CONTed it", pid);
Denys Vlasenko71d3d292013-06-21 16:19:46 +02002090 continue;
Roland McGrathe85bbfe2003-01-09 06:53:31 +00002091 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002092 }
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002093
Denys Vlasenkoce7d9532013-02-05 16:36:13 +01002094 clear_regs();
2095 if (WIFSTOPPED(status))
2096 get_regs(pid);
2097
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002098 /* Under Linux, execve changes pid to thread leader's pid,
2099 * and we see this changed pid on EVENT_EXEC and later,
2100 * execve sysexit. Leader "disappears" without exit
2101 * notification. Let user know that, drop leader's tcb,
2102 * and fix up pid in execve thread's tcb.
2103 * Effectively, execve thread's tcb replaces leader's tcb.
2104 *
2105 * BTW, leader is 'stuck undead' (doesn't report WIFEXITED
2106 * on exit syscall) in multithreaded programs exactly
2107 * in order to handle this case.
2108 *
2109 * PTRACE_GETEVENTMSG returns old pid starting from Linux 3.0.
2110 * On 2.6 and earlier, it can return garbage.
2111 */
2112 if (event == PTRACE_EVENT_EXEC && os_release >= KERNEL_VERSION(3,0,0)) {
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01002113 FILE *fp;
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002114 struct tcb *execve_thread;
2115 long old_pid = 0;
2116
2117 if (ptrace(PTRACE_GETEVENTMSG, pid, NULL, (long) &old_pid) < 0)
2118 goto dont_switch_tcbs;
Denys Vlasenko6162a3f2013-07-04 09:26:24 +02002119 /* Avoid truncation in pid2tcb() param passing */
2120 if (old_pid > UINT_MAX)
2121 goto dont_switch_tcbs;
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002122 if (old_pid <= 0 || old_pid == pid)
2123 goto dont_switch_tcbs;
2124 execve_thread = pid2tcb(old_pid);
2125 /* It should be !NULL, but I feel paranoid */
2126 if (!execve_thread)
2127 goto dont_switch_tcbs;
2128
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002129 if (execve_thread->curcol != 0) {
2130 /*
2131 * One case we are here is -ff:
2132 * try "strace -oLOG -ff test/threaded_execve"
2133 */
2134 fprintf(execve_thread->outf, " <pid changed to %d ...>\n", pid);
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01002135 /*execve_thread->curcol = 0; - no need, see code below */
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002136 }
2137 /* Swap output FILEs (needed for -ff) */
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01002138 fp = execve_thread->outf;
2139 execve_thread->outf = tcp->outf;
2140 tcp->outf = fp;
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002141 /* And their column positions */
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01002142 execve_thread->curcol = tcp->curcol;
2143 tcp->curcol = 0;
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002144 /* Drop leader, but close execve'd thread outfile (if -ff) */
2145 droptcb(tcp);
2146 /* Switch to the thread, reusing leader's outfile and pid */
2147 tcp = execve_thread;
2148 tcp->pid = pid;
2149 if (cflag != CFLAG_ONLY_STATS) {
2150 printleader(tcp);
2151 tprintf("+++ superseded by execve in pid %lu +++\n", old_pid);
2152 line_ended();
2153 tcp->flags |= TCB_REPRINT;
2154 }
2155 }
2156 dont_switch_tcbs:
2157
Denys Vlasenko2a3d2752013-05-14 16:07:46 +02002158 if (event == PTRACE_EVENT_EXEC) {
2159 if (detach_on_execve && !skip_one_b_execve)
2160 detach(tcp); /* do "-b execve" thingy */
2161 skip_one_b_execve = 0;
Denys Vlasenko8511f2a2012-03-22 09:35:51 +01002162 }
2163
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002164 /* Set current output file */
Denys Vlasenko6764f8f2012-03-22 09:56:20 +01002165 current_tcp = tcp;
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002166
Denys Vlasenko13d22f12011-06-24 23:01:57 +02002167 if (cflag) {
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002168 tv_sub(&tcp->dtime, &ru.ru_stime, &tcp->stime);
2169 tcp->stime = ru.ru_stime;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002170 }
Roland McGratheb9e2e82009-06-02 16:49:22 -07002171
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002172 if (WIFSIGNALED(status)) {
Dmitry V. Levina6809652008-11-10 17:14:58 +00002173 if (pid == strace_child)
2174 exit_code = 0x100 | WTERMSIG(status);
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00002175 if (cflag != CFLAG_ONLY_STATS
Denys Vlasenkoa9fe13c2013-02-22 13:26:10 +01002176 && (qual_flags[WTERMSIG(status)] & QUAL_SIGNAL)
2177 ) {
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002178 printleader(tcp);
Denys Vlasenko13d22f12011-06-24 23:01:57 +02002179#ifdef WCOREDUMP
Denys Vlasenko000b6012012-01-28 01:25:03 +01002180 tprintf("+++ killed by %s %s+++\n",
Roland McGrath2efe8792004-01-13 09:59:45 +00002181 signame(WTERMSIG(status)),
Denys Vlasenko13d22f12011-06-24 23:01:57 +02002182 WCOREDUMP(status) ? "(core dumped) " : "");
2183#else
Denys Vlasenko000b6012012-01-28 01:25:03 +01002184 tprintf("+++ killed by %s +++\n",
Denys Vlasenko13d22f12011-06-24 23:01:57 +02002185 signame(WTERMSIG(status)));
Roland McGrath2efe8792004-01-13 09:59:45 +00002186#endif
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002187 line_ended();
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002188 }
2189 droptcb(tcp);
2190 continue;
2191 }
2192 if (WIFEXITED(status)) {
Dmitry V. Levina6809652008-11-10 17:14:58 +00002193 if (pid == strace_child)
2194 exit_code = WEXITSTATUS(status);
Daniel P. Berrange01997cf2013-05-13 11:30:55 +01002195 if (cflag != CFLAG_ONLY_STATS &&
2196 qflag < 2) {
Denys Vlasenko19cdada2011-08-17 10:45:32 +02002197 printleader(tcp);
Denys Vlasenko000b6012012-01-28 01:25:03 +01002198 tprintf("+++ exited with %d +++\n", WEXITSTATUS(status));
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002199 line_ended();
Denys Vlasenko19cdada2011-08-17 10:45:32 +02002200 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002201 droptcb(tcp);
2202 continue;
2203 }
2204 if (!WIFSTOPPED(status)) {
2205 fprintf(stderr, "PANIC: pid %u not stopped\n", pid);
2206 droptcb(tcp);
2207 continue;
2208 }
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002209
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002210 /* Is this the very first time we see this tracee stopped? */
2211 if (tcp->flags & TCB_STARTUP) {
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01002212 if (debug_flag)
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002213 fprintf(stderr, "pid %d has TCB_STARTUP, initializing it\n", tcp->pid);
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002214 tcp->flags &= ~TCB_STARTUP;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002215 if (tcp->flags & TCB_BPTSET) {
Roland McGrath02203312007-06-11 22:06:31 +00002216 /*
2217 * One example is a breakpoint inherited from
Denys Vlasenko2ecba322011-08-21 17:35:39 +02002218 * parent through fork().
Roland McGrath02203312007-06-11 22:06:31 +00002219 */
Denys Vlasenko6cda73f2011-09-02 16:23:53 +02002220 if (clearbpt(tcp) < 0) {
2221 /* Pretty fatal */
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002222 droptcb(tcp);
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02002223 exit_code = 1;
2224 return;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002225 }
2226 }
Denys Vlasenkoc169d942013-07-10 14:33:05 +02002227 if (!use_seize && ptrace_setoptions) {
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01002228 if (debug_flag)
Denys Vlasenkoc169d942013-07-10 14:33:05 +02002229 fprintf(stderr, "setting opts 0x%x on pid %d\n", ptrace_setoptions, tcp->pid);
Denys Vlasenko44f87ef2011-08-17 15:18:21 +02002230 if (ptrace(PTRACE_SETOPTIONS, tcp->pid, NULL, ptrace_setoptions) < 0) {
2231 if (errno != ESRCH) {
2232 /* Should never happen, really */
2233 perror_msg_and_die("PTRACE_SETOPTIONS");
Denys Vlasenko3454e4b2011-05-23 21:29:03 +02002234 }
2235 }
2236 }
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002237 }
2238
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002239 sig = WSTOPSIG(status);
2240
Denys Vlasenkof7db5dd2012-01-28 01:16:02 +01002241 if (event != 0) {
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002242 /* Ptrace event */
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01002243#if USE_SEIZE
Denys Vlasenko26bc0602012-07-10 16:36:32 +02002244 if (event == PTRACE_EVENT_STOP) {
Denys Vlasenko67038162012-01-29 16:46:46 +01002245 /*
2246 * PTRACE_INTERRUPT-stop or group-stop.
2247 * PTRACE_INTERRUPT-stop has sig == SIGTRAP here.
2248 */
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002249 if (sig == SIGSTOP
2250 || sig == SIGTSTP
2251 || sig == SIGTTIN
2252 || sig == SIGTTOU
2253 ) {
2254 stopped = 1;
2255 goto show_stopsig;
2256 }
2257 }
2258#endif
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002259 goto restart_tracee_with_sig_0;
2260 }
2261
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002262 /* Is this post-attach SIGSTOP?
2263 * Interestingly, the process may stop
2264 * with STOPSIG equal to some other signal
2265 * than SIGSTOP if we happend to attach
2266 * just before the process takes a signal.
2267 */
2268 if (sig == SIGSTOP && (tcp->flags & TCB_IGNORE_ONE_SIGSTOP)) {
Denys Vlasenkoa50d2a82012-03-15 12:49:52 +01002269 if (debug_flag)
Denys Vlasenkof88837a2011-09-05 14:05:46 +02002270 fprintf(stderr, "ignored SIGSTOP on pid %d\n", tcp->pid);
2271 tcp->flags &= ~TCB_IGNORE_ONE_SIGSTOP;
Denys Vlasenko6cda73f2011-09-02 16:23:53 +02002272 goto restart_tracee_with_sig_0;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002273 }
2274
Denys Vlasenko6cda73f2011-09-02 16:23:53 +02002275 if (sig != syscall_trap_sig) {
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002276 siginfo_t si;
2277
2278 /* Nonzero (true) if tracee is stopped by signal
2279 * (as opposed to "tracee received signal").
Denys Vlasenkoa44f9692012-03-21 11:06:20 +01002280 * TODO: shouldn't we check for errno == EINVAL too?
2281 * We can get ESRCH instead, you know...
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002282 */
2283 stopped = (ptrace(PTRACE_GETSIGINFO, pid, 0, (long) &si) < 0);
Denys Vlasenko5c9d8f42013-02-19 15:30:12 +01002284#if USE_SEIZE
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002285 show_stopsig:
Denys Vlasenko67038162012-01-29 16:46:46 +01002286#endif
Dmitry V. Levine3a7ef52010-03-28 19:24:54 +00002287 if (cflag != CFLAG_ONLY_STATS
Dmitry V. Levine8ff4c62013-05-28 20:27:10 +00002288 && !hide_log_until_execve
2289 && (qual_flags[sig] & QUAL_SIGNAL)
2290 ) {
Dmitry V. Levine8ff4c62013-05-28 20:27:10 +00002291 printleader(tcp);
2292 if (!stopped) {
2293 tprintf("--- %s ", signame(sig));
2294 printsiginfo(&si, verbose(tcp));
Denys Vlasenko5a2483b2013-07-01 12:49:14 +02002295 tprints(" ---\n");
Dmitry V. Levine8ff4c62013-05-28 20:27:10 +00002296 } else
Denys Vlasenko5a2483b2013-07-01 12:49:14 +02002297 tprintf("--- stopped by %s ---\n",
2298 signame(sig));
Dmitry V. Levine8ff4c62013-05-28 20:27:10 +00002299 line_ended();
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002300 }
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002301
2302 if (!stopped)
2303 /* It's signal-delivery-stop. Inject the signal */
2304 goto restart_tracee;
2305
2306 /* It's group-stop */
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002307 if (use_seize) {
2308 /*
2309 * This ends ptrace-stop, but does *not* end group-stop.
2310 * This makes stopping signals work properly on straced process
2311 * (that is, process really stops. It used to continue to run).
2312 */
2313 if (ptrace_restart(PTRACE_LISTEN, tcp, 0) < 0) {
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02002314 /* Note: ptrace_restart emitted error message */
2315 exit_code = 1;
2316 return;
Denys Vlasenko31fa8a22012-01-29 02:01:44 +01002317 }
2318 continue;
2319 }
2320 /* We don't have PTRACE_LISTEN support... */
Denys Vlasenko6cda73f2011-09-02 16:23:53 +02002321 goto restart_tracee;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002322 }
Denys Vlasenko2ecba322011-08-21 17:35:39 +02002323
2324 /* We handled quick cases, we are permitted to interrupt now. */
Roland McGrath02203312007-06-11 22:06:31 +00002325 if (interrupted)
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02002326 return;
Denys Vlasenko2ecba322011-08-21 17:35:39 +02002327
2328 /* This should be syscall entry or exit.
2329 * (Or it still can be that pesky post-execve SIGTRAP!)
2330 * Handle it.
2331 */
Denys Vlasenko23506752012-03-21 10:32:49 +01002332 if (trace_syscall(tcp) < 0) {
2333 /* ptrace() failed in trace_syscall().
Roland McGratheb9e2e82009-06-02 16:49:22 -07002334 * Likely a result of process disappearing mid-flight.
Denys Vlasenko23506752012-03-21 10:32:49 +01002335 * Observed case: exit_group() or SIGKILL terminating
Denys Vlasenkof1e69032012-01-04 15:15:26 +01002336 * all processes in thread group.
Denys Vlasenko7de265d2012-03-13 11:44:31 +01002337 * We assume that ptrace error was caused by process death.
Denys Vlasenkof2025022012-03-09 15:29:45 +01002338 * We used to detach(tcp) here, but since we no longer
2339 * implement "detach before death" policy/hack,
2340 * we can let this process to report its death to us
2341 * normally, via WIFEXITED or WIFSIGNALED wait status.
2342 */
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002343 continue;
2344 }
Denys Vlasenko6cda73f2011-09-02 16:23:53 +02002345 restart_tracee_with_sig_0:
2346 sig = 0;
2347 restart_tracee:
Denys Vlasenko6cda73f2011-09-02 16:23:53 +02002348 if (ptrace_restart(PTRACE_SYSCALL, tcp, sig) < 0) {
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02002349 /* Note: ptrace_restart emitted error message */
2350 exit_code = 1;
2351 return;
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002352 }
Denys Vlasenko7c41ce22013-07-08 13:55:04 +02002353 } /* while (1) */
Wichert Akkerman76baf7c1999-02-19 00:21:36 +00002354}
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002355
2356int
2357main(int argc, char *argv[])
2358{
2359 init(argc, argv);
2360
2361 /* Run main tracing loop */
Denys Vlasenkod0ffdf42013-07-01 13:02:33 +02002362 trace();
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002363
2364 cleanup();
2365 fflush(NULL);
Dmitry V. Levincf534362012-07-12 20:54:46 +00002366 if (shared_log != stderr)
2367 fclose(shared_log);
2368 if (popen_pid) {
2369 while (waitpid(popen_pid, NULL, 0) < 0 && errno == EINTR)
2370 ;
2371 }
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002372 if (exit_code > 0xff) {
2373 /* Avoid potential core file clobbering. */
Dmitry V. Levinc8938e02013-03-20 21:40:15 +00002374 struct_rlimit rlim = {0, 0};
2375 set_rlimit(RLIMIT_CORE, &rlim);
Denys Vlasenkoecc8b972012-03-12 23:05:25 +01002376
2377 /* Child was killed by a signal, mimic that. */
2378 exit_code &= 0xff;
2379 signal(exit_code, SIG_DFL);
2380 raise(exit_code);
2381 /* Paranoia - what if this signal is not fatal?
2382 Exit with 128 + signo then. */
2383 exit_code += 128;
2384 }
2385
2386 return exit_code;
2387}