blob: 31ccd697c8d0b0106627dbd6618540b8847a7b62 [file] [log] [blame]
/*
* Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
* Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
* Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
* Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id$
*/
#include "defs.h"
#include <signal.h>
#include <errno.h>
#include <sys/param.h>
#include <fcntl.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <pwd.h>
#include <grp.h>
#include <string.h>
#ifdef SVR4
#include <sys/stropts.h>
#include <poll.h>
#ifdef HAVE_MP_PROCFS
#include <sys/uio.h>
#endif
#endif
int debug = 0, followfork = 0, followvfork = 0, interactive = 0;
int rflag = 0, tflag = 0, dtime = 0, cflag = 0;
int iflag = 0, xflag = 0, qflag = 0;
int pflag_seen = 0;
char *username = NULL;
uid_t run_uid;
gid_t run_gid;
int acolumn = DEFAULT_ACOLUMN;
int max_strlen = DEFAULT_STRLEN;
char *outfname = NULL;
FILE *outf;
struct tcb tcbtab[MAX_PROCS];
int nprocs;
char *progname;
extern char version[];
extern char **environ;
static struct tcb *pid2tcb P((int pid));
static int trace P((void));
static void cleanup P((void));
static void interrupt P((int sig));
static sigset_t empty_set, blocked_set;
#ifdef HAVE_SIG_ATOMIC_T
static volatile sig_atomic_t interrupted;
#else /* !HAVE_SIG_ATOMIC_T */
#ifdef __STDC__
static volatile int interrupted;
#else /* !__STDC__ */
static int interrupted;
#endif /* !__STDC__ */
#endif /* !HAVE_SIG_ATOMIC_T */
#ifdef SVR4
static struct tcb *pfd2tcb P((int pfd));
static void reaper P((int sig));
static void rebuild_pollv P((void));
struct pollfd pollv[MAX_PROCS];
#ifndef HAVE_POLLABLE_PROCFS
static void proc_poll_open P((void));
static void proc_poller P((int pfd));
struct proc_pollfd {
int fd;
int revents;
int pid;
};
static int poller_pid;
static int proc_poll_pipe[2] = { -1, -1 };
#endif /* !HAVE_POLLABLE_PROCFS */
#ifdef HAVE_MP_PROCFS
#define POLLWANT POLLWRNORM
#else
#define POLLWANT POLLPRI
#endif
#endif /* SVR4 */
static void
usage(ofp, exitval)
FILE *ofp;
int exitval;
{
fprintf(ofp, "\
usage: strace [-dffhiqrtttTvVxx] [-a column] [-e expr] ... [-o file]\n\
[-p pid] ... [-s strsize] [-u username] [command [arg ...]]\n\
or: strace -c [-e expr] ... [-O overhead] [-S sortby] [command [arg ...]]\n\
-c -- count time, calls, and errors for each syscall and report summary\n\
-f -- follow forks, -ff -- with output into separate files\n\
-F -- attempt to follow vforks, -h -- print help message\n\
-i -- print instruction pointer at time of syscall\n\
-q -- suppress messages about attaching, detaching, etc.\n\
-r -- print relative timestamp, -t -- absolute timestamp, -tt -- with usecs\n\
-T -- print time spent in each syscall, -V -- print version\n\
-v -- verbose mode: print unabbreviated argv, stat, termio[s], etc. args\n\
-x -- print non-ascii strings in hex, -xx -- print all strings in hex\n\
-a column -- alignment COLUMN for printing syscall results (default %d)\n\
-e expr -- a qualifying expression: option=[!]all or option=[!]val1[,val2]...\n\
options: trace, abbrev, verbose, raw, signal, read, or write\n\
-o file -- send trace output to FILE instead of stderr\n\
-O overhead -- set overhead for tracing syscalls to OVERHEAD usecs\n\
-p pid -- trace process with process id PID, may be repeated\n\
-s strsize -- limit length of print strings to STRSIZE chars (default %d)\n\
-S sortby -- sort syscall counts by: time, calls, name, nothing (default %s)\n\
-u username -- run command as username handling setuid and/or setgid\n\
", DEFAULT_ACOLUMN, DEFAULT_STRLEN, DEFAULT_SORTBY);
exit(exitval);
}
#ifdef SVR4
#ifdef MIPS
void
foobar()
{
}
#endif /* MIPS */
#endif /* SVR4 */
int
main(argc, argv)
int argc;
char *argv[];
{
extern int optind;
extern char *optarg;
struct tcb *tcp;
int c, pid = 0;
struct sigaction sa;
static char buf[BUFSIZ];
progname = argv[0];
outf = stderr;
interactive = 1;
qualify("trace=all");
qualify("abbrev=all");
qualify("verbose=all");
qualify("signal=all");
set_sortby(DEFAULT_SORTBY);
set_personality(DEFAULT_PERSONALITY);
while ((c = getopt(argc, argv,
"+cdfFhiqrtTvVxa:e:o:O:p:s:S:u:")) != EOF) {
switch (c) {
case 'c':
cflag++;
dtime++;
break;
case 'd':
debug++;
break;
case 'f':
followfork++;
break;
case 'F':
followvfork++;
break;
case 'h':
usage(stdout, 0);
break;
case 'i':
iflag++;
break;
case 'q':
qflag++;
break;
case 'r':
rflag++;
tflag++;
break;
case 't':
tflag++;
break;
case 'T':
dtime++;
break;
case 'x':
xflag++;
break;
case 'v':
qualify("abbrev=none");
break;
case 'V':
printf("%s\n", version);
exit(0);
break;
case 'a':
acolumn = atoi(optarg);
break;
case 'e':
qualify(optarg);
break;
case 'o':
outfname = strdup(optarg);
break;
case 'O':
set_overhead(atoi(optarg));
break;
case 'p':
if ((pid = atoi(optarg)) == 0) {
fprintf(stderr, "%s: Invalid process id: %s\n",
progname, optarg);
break;
}
if (pid == getpid()) {
fprintf(stderr, "%s: I'm sorry, I can't let you do that, Dave.\n", progname);
break;
}
if ((tcp = alloctcb(pid)) == NULL) {
fprintf(stderr, "%s: tcb table full, please recompile strace\n",
progname);
exit(1);
}
tcp->flags |= TCB_ATTACHED;
pflag_seen++;
break;
case 's':
max_strlen = atoi(optarg);
break;
case 'S':
set_sortby(optarg);
break;
case 'u':
username = strdup(optarg);
break;
default:
usage(stderr, 1);
break;
}
}
/* See if they want to run as another user. */
if (username != NULL) {
struct passwd *pent;
if (getuid() != 0 || geteuid() != 0) {
fprintf(stderr,
"%s: you must be root to use the -u option\n",
progname);
exit(1);
}
if ((pent = getpwnam(username)) == NULL) {
fprintf(stderr, "%s: cannot find user `%s'\n",
progname, optarg);
exit(1);
}
run_uid = pent->pw_uid;
run_gid = pent->pw_gid;
}
else {
run_uid = getuid();
run_gid = getgid();
}
#ifndef SVR4
setreuid(geteuid(), getuid());
#endif
/* See if they want to pipe the output. */
if (outfname && (outfname[0] == '|' || outfname[0] == '!')) {
if ((outf = popen(outfname + 1, "w")) == NULL) {
fprintf(stderr, "%s: can't popen '%s': %s\n",
progname, outfname + 1, strerror(errno));
exit(1);
}
free(outfname);
outfname = NULL;
}
/* Check if they want to redirect the output. */
if (outfname) {
if ((outf = fopen(outfname, "w")) == NULL) {
fprintf(stderr, "%s: can't fopen '%s': %s\n",
progname, outfname, strerror(errno));
exit(1);
}
}
#ifndef SVR4
setreuid(geteuid(), getuid());
#endif
if (!outfname) {
qflag = 1;
setvbuf(outf, buf, _IOLBF, BUFSIZ);
}
else if (optind < argc)
interactive = 0;
else
qflag = 1;
for (c = 0, tcp = tcbtab; c < MAX_PROCS; c++, tcp++) {
/* Reinitialize the output since it may have changed. */
tcp->outf = outf;
if (!(tcp->flags & TCB_INUSE) || !(tcp->flags & TCB_ATTACHED))
continue;
#ifdef SVR4
if (proc_open(tcp, 1) < 0) {
fprintf(stderr, "trouble opening proc file\n");
droptcb(tcp);
continue;
}
#else /* !SVR4 */
if (ptrace(PTRACE_ATTACH, tcp->pid, (char *) 1, 0) < 0) {
perror("attach: ptrace(PTRACE_ATTACH, ...)");
droptcb(tcp);
continue;
}
#endif /* !SVR4 */
if (!qflag)
fprintf(stderr,
"Process %u attached - interrupt to quit\n",
pid);
}
if (optind < argc) {
struct stat statbuf;
char *filename;
char pathname[MAXPATHLEN];
filename = argv[optind];
if (strchr(filename, '/'))
strcpy(pathname, filename);
#ifdef USE_DEBUGGING_EXEC
/*
* Debuggers customarily check the current directory
* first regardless of the path but doing that gives
* security geeks a panic attack.
*/
else if (stat(filename, &statbuf) == 0)
strcpy(pathname, filename);
#endif /* USE_DEBUGGING_EXEC */
else {
char *path;
int m, n, len;
for (path = getenv("PATH"); path && *path; path += m) {
if (strchr(path, ':')) {
n = strchr(path, ':') - path;
m = n + 1;
}
else
m = n = strlen(path);
if (n == 0) {
getcwd(pathname, MAXPATHLEN);
len = strlen(pathname);
}
else {
strncpy(pathname, path, n);
len = n;
}
if (len && pathname[len - 1] != '/')
pathname[len++] = '/';
strcpy(pathname + len, filename);
if (stat(pathname, &statbuf) == 0)
break;
}
}
if (stat(pathname, &statbuf) < 0) {
fprintf(stderr, "%s: %s: command not found\n",
progname, filename);
exit(1);
}
switch (pid = fork()) {
case -1:
perror("strace: fork");
cleanup();
exit(1);
break;
case 0: {
#ifdef SVR4
if (outf != stderr) close (fileno (outf));
#ifdef MIPS
/* Kludge for SGI, see proc_open for details. */
sa.sa_handler = foobar;
sa.sa_flags = 0;
sigemptyset(&sa.sa_mask);
sigaction(SIGINT, &sa, NULL);
#endif /* MIPS */
pause();
#else /* !SVR4 */
if (ptrace(PTRACE_TRACEME, 0, (char *) 1, 0) < 0) {
perror("strace: ptrace(PTRACE_TRACEME, ...)");
return -1;
}
if (debug)
kill(getpid(), SIGSTOP);
if (username != NULL || geteuid() == 0) {
uid_t run_euid = run_uid;
gid_t run_egid = run_gid;
if (statbuf.st_mode & S_ISUID)
run_euid = statbuf.st_uid;
if (statbuf.st_mode & S_ISGID)
run_egid = statbuf.st_gid;
/*
* It is important to set groups before we
* lose privileges on setuid.
*/
if (username != NULL
&& initgroups(username, run_gid) < 0) {
perror("initgroups");
exit(1);
}
if (setregid(run_gid, run_egid) < 0) {
perror("setregid");
exit(1);
}
if (setreuid(run_uid, run_euid) < 0) {
perror("setreuid");
exit(1);
}
}
else
setreuid(run_uid, run_uid);
#endif /* !SVR4 */
execv(pathname, &argv[optind]);
perror("strace: exec");
_exit(1);
break;
}
default:
if ((tcp = alloctcb(pid)) == NULL) {
fprintf(stderr, "tcb table full\n");
cleanup();
exit(1);
}
#ifdef SVR4
if (proc_open(tcp, 0) < 0) {
fprintf(stderr, "trouble opening proc file\n");
cleanup();
exit(1);
}
#endif /* SVR4 */
#ifndef SVR4
fake_execve(tcp, pathname, &argv[optind], environ);
#endif
break;
}
}
else if (pflag_seen == 0)
usage(stderr, 1);
sigemptyset(&empty_set);
sigemptyset(&blocked_set);
sa.sa_handler = SIG_IGN;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sigaction(SIGTTOU, &sa, NULL);
sigaction(SIGTTIN, &sa, NULL);
if (interactive) {
sigaddset(&blocked_set, SIGHUP);
sigaddset(&blocked_set, SIGINT);
sigaddset(&blocked_set, SIGQUIT);
sigaddset(&blocked_set, SIGPIPE);
sigaddset(&blocked_set, SIGTERM);
sa.sa_handler = interrupt;
#ifdef SUNOS4
/* POSIX signals on sunos4.1 are a little broken. */
sa.sa_flags = SA_INTERRUPT;
#endif /* SUNOS4 */
}
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGPIPE, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
#ifdef SVR4
sa.sa_handler = reaper;
sigaction(SIGCHLD, &sa, NULL);
#endif /* SVR4 */
if (trace() < 0)
exit(1);
cleanup();
exit(0);
}
void
newoutf(tcp)
struct tcb *tcp;
{
char name[MAXPATHLEN];
FILE *fp;
if (outfname && followfork > 1) {
sprintf(name, "%s.%u", outfname, tcp->pid);
#ifndef SVR4
setreuid(geteuid(), getuid());
#endif
fp = fopen(name, "w");
#ifndef SVR4
setreuid(geteuid(), getuid());
#endif
if (fp == NULL) {
perror("fopen");
return;
}
tcp->outf = fp;
}
return;
}
struct tcb *
alloctcb(pid)
int pid;
{
int i;
struct tcb *tcp;
for (i = 0, tcp = tcbtab; i < MAX_PROCS; i++, tcp++) {
if ((tcp->flags & TCB_INUSE) == 0) {
tcp->pid = pid;
tcp->parent = NULL;
tcp->nchildren = 0;
tcp->flags = TCB_INUSE | TCB_STARTUP;
tcp->outf = outf; /* Initialise to current out file */
tcp->stime.tv_sec = 0;
tcp->stime.tv_usec = 0;
tcp->pfd = -1;
nprocs++;
return tcp;
}
}
return NULL;
}
#ifdef SVR4
int
proc_open(tcp, attaching)
struct tcb *tcp;
int attaching;
{
char proc[32];
long arg;
sysset_t sc_enter, sc_exit;
sigset_t signals;
fltset_t faults;
#ifndef HAVE_POLLABLE_PROCFS
static int last_pfd;
#endif
#ifdef HAVE_MP_PROCFS
/* Open the process pseudo-files in /proc. */
sprintf(proc, "/proc/%d/ctl", tcp->pid);
if ((tcp->pfd = open(proc, O_WRONLY|O_EXCL)) < 0) {
perror("strace: open(\"/proc/...\", ...)");
return -1;
}
if ((arg = fcntl(tcp->pfd, F_GETFD)) < 0) {
perror("F_GETFD");
return -1;
}
if (fcntl(tcp->pfd, F_SETFD, arg|FD_CLOEXEC) < 0) {
perror("F_SETFD");
return -1;
}
sprintf(proc, "/proc/%d/status", tcp->pid);
if ((tcp->pfd_stat = open(proc, O_RDONLY|O_EXCL)) < 0) {
perror("strace: open(\"/proc/...\", ...)");
return -1;
}
if ((arg = fcntl(tcp->pfd_stat, F_GETFD)) < 0) {
perror("F_GETFD");
return -1;
}
if (fcntl(tcp->pfd_stat, F_SETFD, arg|FD_CLOEXEC) < 0) {
perror("F_SETFD");
return -1;
}
sprintf(proc, "/proc/%d/as", tcp->pid);
if ((tcp->pfd_as = open(proc, O_RDONLY|O_EXCL)) < 0) {
perror("strace: open(\"/proc/...\", ...)");
return -1;
}
if ((arg = fcntl(tcp->pfd_as, F_GETFD)) < 0) {
perror("F_GETFD");
return -1;
}
if (fcntl(tcp->pfd_as, F_SETFD, arg|FD_CLOEXEC) < 0) {
perror("F_SETFD");
return -1;
}
#else
/* Open the process pseudo-file in /proc. */
sprintf(proc, "/proc/%d", tcp->pid);
if ((tcp->pfd = open(proc, O_RDWR|O_EXCL)) < 0) {
perror("strace: open(\"/proc/...\", ...)");
return -1;
}
if ((arg = fcntl(tcp->pfd, F_GETFD)) < 0) {
perror("F_GETFD");
return -1;
}
if (fcntl(tcp->pfd, F_SETFD, arg|FD_CLOEXEC) < 0) {
perror("F_SETFD");
return -1;
}
#endif
rebuild_pollv();
if (!attaching) {
/*
* Wait for the child to pause. Because of a race
* condition we have to poll for the event.
*/
for (;;) {
if (IOCTL_STATUS (tcp) < 0) {
perror("strace: PIOCSTATUS");
return -1;
}
if (tcp->status.PR_FLAGS & PR_ASLEEP)
break;
}
}
/* Stop the process so that we own the stop. */
if (IOCTL(tcp->pfd, PIOCSTOP, NULL) < 0) {
perror("strace: PIOCSTOP");
return -1;
}
#ifdef PIOCSET
/* Set Run-on-Last-Close. */
arg = PR_RLC;
if (IOCTL(tcp->pfd, PIOCSET, &arg) < 0) {
perror("PIOCSET PR_RLC");
return -1;
}
/* Set or Reset Inherit-on-Fork. */
arg = PR_FORK;
if (IOCTL(tcp->pfd, followfork ? PIOCSET : PIOCRESET, &arg) < 0) {
perror("PIOC{SET,RESET} PR_FORK");
return -1;
}
#else /* !PIOCSET */
if (ioctl(tcp->pfd, PIOCSRLC) < 0) {
perror("PIOCSRLC");
return -1;
}
if (ioctl(tcp->pfd, followfork ? PIOCSFORK : PIOCRFORK) < 0) {
perror("PIOC{S,R}FORK");
return -1;
}
#endif /* !PIOCSET */
/* Enable all syscall entries. */
prfillset(&sc_enter);
if (IOCTL(tcp->pfd, PIOCSENTRY, &sc_enter) < 0) {
perror("PIOCSENTRY");
return -1;
}
/* Enable all syscall exits. */
prfillset(&sc_exit);
if (IOCTL(tcp->pfd, PIOCSEXIT, &sc_exit) < 0) {
perror("PIOSEXIT");
return -1;
}
/* Enable all signals. */
prfillset(&signals);
if (IOCTL(tcp->pfd, PIOCSTRACE, &signals) < 0) {
perror("PIOCSTRACE");
return -1;
}
/* Enable all faults. */
prfillset(&faults);
if (IOCTL(tcp->pfd, PIOCSFAULT, &faults) < 0) {
perror("PIOCSFAULT");
return -1;
}
if (!attaching) {
#ifdef MIPS
/*
* The SGI PRSABORT doesn't work for pause() so
* we send it a caught signal to wake it up.
*/
kill(tcp->pid, SIGINT);
#else /* !MIPS */
/* The child is in a pause(), abort it. */
arg = PRSABORT;
if (IOCTL (tcp->pfd, PIOCRUN, &arg) < 0) {
perror("PIOCRUN");
return -1;
}
#endif /* !MIPS */
for (;;) {
/* Wait for the child to do something. */
if (IOCTL_WSTOP (tcp) < 0) {
perror("PIOCWSTOP");
return -1;
}
if (tcp->status.PR_WHY == PR_SYSENTRY) {
#ifdef HAVE_PR_SYSCALL
int scno = tcp->status.pr_syscall;
#else /* !HAVE_PR_SYSCALL */
int scno = tcp->status.PR_WHAT;
#endif /* !HAVE_PR_SYSCALL */
if (scno == SYS_execve)
break;
}
/* Set it running: maybe execve will be next. */
arg = 0;
if (IOCTL(tcp->pfd, PIOCRUN, &arg) < 0) {
perror("PIOCRUN");
return -1;
}
}
}
#ifndef HAVE_POLLABLE_PROCFS
if (proc_poll_pipe[0] != -1)
proc_poller(tcp->pfd);
else if (nprocs > 1) {
proc_poll_open();
proc_poller(last_pfd);
proc_poller(tcp->pfd);
}
last_pfd = tcp->pfd;
#endif /* !HAVE_POLLABLE_PROCFS */
return 0;
}
#endif /* SVR4 */
static struct tcb *
pid2tcb(pid)
int pid;
{
int i;
struct tcb *tcp;
for (i = 0, tcp = tcbtab; i < MAX_PROCS; i++, tcp++) {
if (pid && tcp->pid != pid)
continue;
if (tcp->flags & TCB_INUSE)
return tcp;
}
return NULL;
}
#ifdef SVR4
static struct tcb *
pfd2tcb(pfd)
int pfd;
{
int i;
struct tcb *tcp;
for (i = 0, tcp = tcbtab; i < MAX_PROCS; i++, tcp++) {
if (tcp->pfd != pfd)
continue;
if (tcp->flags & TCB_INUSE)
return tcp;
}
return NULL;
}
#endif /* SVR4 */
void
droptcb(tcp)
struct tcb *tcp;
{
if (tcp->pid == 0)
return;
nprocs--;
tcp->pid = 0;
tcp->flags = 0;
if (tcp->pfd != -1) {
close(tcp->pfd);
tcp->pfd = -1;
#ifdef SVR4
rebuild_pollv();
#endif
}
if (tcp->parent != NULL) {
tcp->parent->nchildren--;
tcp->parent = NULL;
}
#if 0
if (tcp->outf != stderr)
fclose(tcp->outf);
#endif
tcp->outf = 0;
}
#ifndef SVR4
static int
resume(tcp)
struct tcb *tcp;
{
if (tcp == NULL)
return -1;
if (!(tcp->flags & TCB_SUSPENDED)) {
fprintf(stderr, "PANIC: pid %u not suspended\n", tcp->pid);
return -1;
}
tcp->flags &= ~TCB_SUSPENDED;
if (ptrace(PTRACE_SYSCALL, tcp->pid, (char *) 1, 0) < 0) {
perror("resume: ptrace(PTRACE_SYSCALL, ...)");
return -1;
}
if (!qflag)
fprintf(stderr, "Process %u resumed\n", tcp->pid);
return 0;
}
#endif /* !SVR4 */
/* detach traced process; continue with sig */
static int
detach(tcp, sig)
struct tcb *tcp;
int sig;
{
int error = 0;
#ifdef LINUX
int status;
#endif
if (tcp->flags & TCB_BPTSET)
sig = SIGKILL;
#ifdef LINUX
/*
* Linux wrongly insists the child be stopped
* before detaching. Arghh. We go through hoops
* to make a clean break of things.
*/
#if defined(SPARC)
#undef PTRACE_DETACH
#define PTRACE_DETACH PTRACE_SUNDETACH
#endif
if ((error = ptrace(PTRACE_DETACH, tcp->pid, (char *) 1, sig)) == 0) {
/* On a clear day, you can see forever. */
}
else if (errno != ESRCH) {
/* Shouldn't happen. */
perror("detach: ptrace(PTRACE_DETACH, ...)");
}
else if (kill(tcp->pid, 0) < 0) {
if (errno != ESRCH)
perror("detach: checking sanity");
}
else if (kill(tcp->pid, SIGSTOP) < 0) {
if (errno != ESRCH)
perror("detach: stopping child");
}
else {
for (;;) {
if (waitpid(tcp->pid, &status, 0) < 0) {
if (errno != ECHILD)
perror("detach: waiting");
break;
}
if (!WIFSTOPPED(status)) {
/* Au revoir, mon ami. */
break;
}
if (WSTOPSIG(status) == SIGSTOP) {
if ((error = ptrace(PTRACE_DETACH,
tcp->pid, (char *) 1, sig)) < 0) {
if (errno != ESRCH)
perror("detach: ptrace(PTRACE_DETACH, ...)");
/* I died trying. */
}
break;
}
if ((error = ptrace(PTRACE_CONT, tcp->pid, (char *) 1,
WSTOPSIG(status) == SIGTRAP ?
0 : WSTOPSIG(status))) < 0) {
if (errno != ESRCH)
perror("detach: ptrace(PTRACE_CONT, ...)");
break;
}
}
}
#endif /* LINUX */
#if defined(SUNOS4)
/* PTRACE_DETACH won't respect `sig' argument, so we post it here. */
if (sig && kill(tcp->pid, sig) < 0)
perror("detach: kill");
sig = 0;
if ((error = ptrace(PTRACE_DETACH, tcp->pid, (char *) 1, sig)) < 0)
perror("detach: ptrace(PTRACE_DETACH, ...)");
#endif /* SUNOS4 */
#ifndef SVR4
if (waiting_parent(tcp))
error = resume(tcp->parent);
#endif /* !SVR4 */
if (!qflag)
fprintf(stderr, "Process %u detached\n", tcp->pid);
droptcb(tcp);
return error;
}
#ifdef SVR4
static void
reaper(sig)
int sig;
{
int pid;
int status;
while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
#if 0
struct tcb *tcp;
tcp = pid2tcb(pid);
if (tcp)
droptcb(tcp);
#endif
}
}
#endif /* SVR4 */
static void
cleanup()
{
int i;
struct tcb *tcp;
for (i = 0, tcp = tcbtab; i < MAX_PROCS; i++, tcp++) {
if (!(tcp->flags & TCB_INUSE))
continue;
if (debug)
fprintf(stderr,
"cleanup: looking at pid %u\n", tcp->pid);
if (tcp_last &&
(!outfname || followfork < 2 || tcp_last == tcp)) {
tprintf(" <unfinished ...>\n");
tcp_last = NULL;
}
if (tcp->flags & TCB_ATTACHED)
detach(tcp, 0);
else {
kill(tcp->pid, SIGCONT);
kill(tcp->pid, SIGTERM);
}
}
if (cflag)
call_summary(outf);
}
static void
interrupt(sig)
int sig;
{
interrupted = 1;
}
#ifndef HAVE_STRERROR
#ifndef SYS_ERRLIST_DECLARED
extern int sys_nerr;
extern char *sys_errlist[];
#endif /* SYS_ERRLIST_DECLARED */
const char *
strerror(errno)
int errno;
{
static char buf[64];
if (errno < 1 || errno >= sys_nerr) {
sprintf(buf, "Unknown error %d", errno);
return buf;
}
return sys_errlist[errno];
}
#endif /* HAVE_STERRROR */
#ifndef HAVE_STRSIGNAL
#ifndef SYS_SIGLIST_DECLARED
#ifdef HAVE__SYS_SIGLIST
extern char *_sys_siglist[];
#else
extern char *sys_siglist[];
#endif
#endif /* SYS_SIGLIST_DECLARED */
const char *
strsignal(sig)
int sig;
{
static char buf[64];
if (sig < 1 || sig >= NSIG) {
sprintf(buf, "Unknown signal %d", sig);
return buf;
}
#ifdef HAVE__SYS_SIGLIST
return _sys_siglist[sig];
#else
return sys_siglist[sig];
#endif
}
#endif /* HAVE_STRSIGNAL */
#ifdef SVR4
static void
rebuild_pollv()
{
int i, j;
struct tcb *tcp;
for (i = j = 0, tcp = tcbtab; i < MAX_PROCS; i++, tcp++) {
if (!(tcp->flags & TCB_INUSE))
continue;
pollv[j].fd = tcp->pfd;
pollv[j].events = POLLWANT;
j++;
}
if (j != nprocs) {
fprintf(stderr, "strace: proc miscount\n");
exit(1);
}
}
#ifndef HAVE_POLLABLE_PROCFS
static void
proc_poll_open()
{
int arg;
int i;
if (pipe(proc_poll_pipe) < 0) {
perror("pipe");
exit(1);
}
for (i = 0; i < 2; i++) {
if ((arg = fcntl(proc_poll_pipe[i], F_GETFD)) < 0) {
perror("F_GETFD");
exit(1);
}
if (fcntl(proc_poll_pipe[i], F_SETFD, arg|FD_CLOEXEC) < 0) {
perror("F_SETFD");
exit(1);
}
}
}
static int
proc_poll(pollv, nfds, timeout)
struct pollfd *pollv;
int nfds;
int timeout;
{
int i;
int n;
struct proc_pollfd pollinfo;
if ((n = read(proc_poll_pipe[0], &pollinfo, sizeof(pollinfo))) < 0)
return n;
if (n != sizeof(struct proc_pollfd)) {
fprintf(stderr, "panic: short read: %d\n", n);
exit(1);
}
for (i = 0; i < nprocs; i++) {
if (pollv[i].fd == pollinfo.fd)
pollv[i].revents = pollinfo.revents;
else
pollv[i].revents = 0;
}
poller_pid = pollinfo.pid;
return 1;
}
static void
wakeup_handler(sig)
int sig;
{
}
static void
proc_poller(pfd)
int pfd;
{
struct proc_pollfd pollinfo;
struct sigaction sa;
sigset_t blocked_set, empty_set;
int i;
int n;
struct rlimit rl;
switch (fork()) {
case -1:
perror("fork");
_exit(0);
case 0:
break;
default:
return;
}
sa.sa_handler = interactive ? SIG_DFL : SIG_IGN;
sa.sa_flags = 0;
sigemptyset(&sa.sa_mask);
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGPIPE, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
sa.sa_handler = wakeup_handler;
sigaction(SIGUSR1, &sa, NULL);
sigemptyset(&blocked_set);
sigaddset(&blocked_set, SIGUSR1);
sigprocmask(SIG_BLOCK, &blocked_set, NULL);
sigemptyset(&empty_set);
if (getrlimit(RLIMIT_NOFILE, &rl) < 0) {
perror("getrlimit(RLIMIT_NOFILE, ...)");
_exit(0);
}
n = rl.rlim_cur;
for (i = 0; i < n; i++) {
if (i != pfd && i != proc_poll_pipe[1])
close(i);
}
pollinfo.fd = pfd;
pollinfo.pid = getpid();
for (;;) {
if (ioctl(pfd, PIOCWSTOP, NULL) < 0)
{
switch (errno) {
case EINTR:
continue;
case EBADF:
pollinfo.revents = POLLERR;
break;
case ENOENT:
pollinfo.revents = POLLHUP;
break;
default:
perror("proc_poller: PIOCWSTOP");
}
write(proc_poll_pipe[1], &pollinfo, sizeof(pollinfo));
_exit(0);
}
pollinfo.revents = POLLWANT;
write(proc_poll_pipe[1], &pollinfo, sizeof(pollinfo));
sigsuspend(&empty_set);
}
}
#endif /* !HAVE_POLLABLE_PROCFS */
static int
choose_pfd()
{
int i, j;
struct tcb *tcp;
static int last;
if (followfork < 2 &&
last < nprocs && (pollv[last].revents & POLLWANT)) {
/*
* The previous process is ready to run again. We'll
* let it do so if it is currently in a syscall. This
* heuristic improves the readability of the trace.
*/
tcp = pfd2tcb(pollv[last].fd);
if (tcp && (tcp->flags & TCB_INSYSCALL))
return pollv[last].fd;
}
for (i = 0; i < nprocs; i++) {
/* Let competing children run round robin. */
j = (i + last + 1) % nprocs;
if (pollv[j].revents & (POLLHUP | POLLERR)) {
tcp = pfd2tcb(pollv[j].fd);
if (!tcp) {
fprintf(stderr, "strace: lost proc\n");
exit(1);
}
droptcb(tcp);
return -1;
}
if (pollv[j].revents & POLLWANT) {
last = j;
return pollv[j].fd;
}
}
fprintf(stderr, "strace: nothing ready\n");
exit(1);
}
static int
trace()
{
#ifdef POLL_HACK
struct tcb *in_syscall;
#endif
struct tcb *tcp;
int pfd;
int what;
int ioctl_result = 0, ioctl_errno = 0;
long arg;
for (;;) {
if (interactive)
sigprocmask(SIG_SETMASK, &empty_set, NULL);
if (nprocs == 0)
break;
switch (nprocs) {
case 1:
#ifndef HAVE_POLLABLE_PROCFS
if (proc_poll_pipe[0] == -1) {
#endif
tcp = pid2tcb(0);
if (!tcp)
continue;
pfd = tcp->pfd;
if (pfd == -1)
continue;
break;
#ifndef HAVE_POLLABLE_PROCFS
}
/* fall through ... */
#endif /* !HAVE_POLLABLE_PROCFS */
default:
#ifdef HAVE_POLLABLE_PROCFS
#ifdef POLL_HACK
/* On some systems (e.g. UnixWare) we get too much ugly
"unfinished..." stuff when multiple proceses are in
syscalls. Here's a nasty hack */
if (in_syscall) {
struct pollfd pv;
tcp = in_syscall;
in_syscall = NULL;
pv.fd = tcp->pfd;
pv.events = POLLWANT;
if ((what = poll (&pv, 1, 1)) < 0) {
if (interrupted)
return 0;
continue;
}
else if (what == 1 && pv.revents & POLLWANT) {
goto FOUND;
}
}
#endif
if (poll(pollv, nprocs, INFTIM) < 0) {
if (interrupted)
return 0;
continue;
}
#else /* !HAVE_POLLABLE_PROCFS */
if (proc_poll(pollv, nprocs, INFTIM) < 0) {
if (interrupted)
return 0;
continue;
}
#endif /* !HAVE_POLLABLE_PROCFS */
pfd = choose_pfd();
if (pfd == -1)
continue;
break;
}
/* Look up `pfd' in our table. */
if ((tcp = pfd2tcb(pfd)) == NULL) {
fprintf(stderr, "unknown pfd: %u\n", pfd);
exit(1);
}
FOUND:
/* Get the status of the process. */
if (!interrupted) {
ioctl_result = IOCTL_WSTOP (tcp);
ioctl_errno = errno;
#ifndef HAVE_POLLABLE_PROCFS
if (proc_poll_pipe[0] != -1) {
if (ioctl_result < 0)
kill(poller_pid, SIGKILL);
else
kill(poller_pid, SIGUSR1);
}
#endif /* !HAVE_POLLABLE_PROCFS */
}
if (interrupted)
return 0;
if (interactive)
sigprocmask(SIG_BLOCK, &blocked_set, NULL);
if (ioctl_result < 0) {
/* Find out what happened if it failed. */
switch (ioctl_errno) {
case EINTR:
case EBADF:
continue;
case ENOENT:
droptcb(tcp);
continue;
default:
perror("PIOCWSTOP");
exit(1);
}
}
/* clear the just started flag */
tcp->flags &= ~TCB_STARTUP;
/* set current output file */
outf = tcp->outf;
if (cflag) {
struct timeval stime;
stime.tv_sec = tcp->status.pr_stime.tv_sec;
stime.tv_usec = tcp->status.pr_stime.tv_nsec/1000;
tv_sub(&tcp->dtime, &stime, &tcp->stime);
tcp->stime = stime;
}
what = tcp->status.PR_WHAT;
switch (tcp->status.PR_WHY) {
case PR_REQUESTED:
if (tcp->status.PR_FLAGS & PR_ASLEEP) {
tcp->status.PR_WHY = PR_SYSENTRY;
if (trace_syscall(tcp) < 0) {
fprintf(stderr, "syscall trouble\n");
exit(1);
}
}
break;
case PR_SYSENTRY:
#ifdef POLL_HACK
in_syscall = tcp;
#endif
case PR_SYSEXIT:
if (trace_syscall(tcp) < 0) {
fprintf(stderr, "syscall trouble\n");
exit(1);
}
break;
case PR_SIGNALLED:
if (!cflag && (qual_flags[what] & QUAL_SIGNAL)) {
printleader(tcp);
tprintf("--- %s (%s) ---",
signame(what), strsignal(what));
printtrailer(tcp);
}
break;
case PR_FAULTED:
if (!cflag && (qual_flags[what] & QUAL_FAULT)) {
printleader(tcp);
tprintf("=== FAULT %d ===", what);
printtrailer(tcp);
}
break;
default:
fprintf(stderr, "odd stop %d\n", tcp->status.PR_WHY);
exit(1);
break;
}
arg = 0;
if (IOCTL (tcp->pfd, PIOCRUN, &arg) < 0) {
perror("PIOCRUN");
exit(1);
}
}
return 0;
}
#else /* !SVR4 */
static int
trace()
{
int pid;
int wait_errno;
int status;
struct tcb *tcp;
#ifdef LINUX
struct rusage ru;
#endif /* LINUX */
while (nprocs != 0) {
if (interactive)
sigprocmask(SIG_SETMASK, &empty_set, NULL);
#ifdef LINUX
pid = wait4(-1, &status, 0, cflag ? &ru : NULL);
#endif /* LINUX */
#ifdef SUNOS4
pid = wait(&status);
#endif /* SUNOS4 */
wait_errno = errno;
if (interactive)
sigprocmask(SIG_BLOCK, &blocked_set, NULL);
if (interrupted)
return 0;
if (pid == -1) {
switch (wait_errno) {
case EINTR:
continue;
case ECHILD:
/*
* We would like to verify this case
* but sometimes a race in Solbourne's
* version of SunOS sometimes reports
* ECHILD before sending us SIGCHILD.
*/
#if 0
if (nprocs == 0)
return 0;
fprintf(stderr, "strace: proc miscount\n");
exit(1);
#endif
return 0;
default:
errno = wait_errno;
perror("strace: wait");
return -1;
}
}
if (debug)
fprintf(stderr, " [wait(%#x) = %u]\n", status, pid);
/* Look up `pid' in our table. */
if ((tcp = pid2tcb(pid)) == NULL) {
fprintf(stderr, "unknown pid: %u\n", pid);
if (WIFSTOPPED(status))
ptrace(PTRACE_CONT, pid, (char *) 1, 0);
exit(1);
}
/* set current output file */
outf = tcp->outf;
if (cflag) {
#ifdef LINUX
tv_sub(&tcp->dtime, &ru.ru_stime, &tcp->stime);
tcp->stime = ru.ru_stime;
#endif /* !LINUX */
}
if (tcp->flags & TCB_SUSPENDED) {
/*
* Apparently, doing any ptrace() call on a stopped
* process, provokes the kernel to report the process
* status again on a subsequent wait(), even if the
* process has not been actually restarted.
* Since we have inspected the arguments of suspended
* processes we end up here testing for this case.
*/
continue;
}
if (WIFSIGNALED(status)) {
if (!cflag
&& (qual_flags[WTERMSIG(status)] & QUAL_SIGNAL)) {
printleader(tcp);
tprintf("+++ killed by %s +++",
signame(WTERMSIG(status)));
printtrailer(tcp);
}
droptcb(tcp);
continue;
}
if (WIFEXITED(status)) {
if (debug)
fprintf(stderr, "pid %u exited\n", pid);
if (tcp->flags & TCB_ATTACHED)
fprintf(stderr,
"PANIC: attached pid %u exited\n",
pid);
droptcb(tcp);
continue;
}
if (!WIFSTOPPED(status)) {
fprintf(stderr, "PANIC: pid %u not stopped\n", pid);
droptcb(tcp);
continue;
}
if (debug)
fprintf(stderr, "pid %u stopped, [%s]\n",
pid, signame(WSTOPSIG(status)));
if (tcp->flags & TCB_STARTUP) {
/*
* This flag is there to keep us in sync.
* Next time this process stops it should
* really be entering a system call.
*/
tcp->flags &= ~TCB_STARTUP;
if (tcp->flags & TCB_ATTACHED) {
/*
* Interestingly, the process may stop
* with STOPSIG equal to some other signal
* than SIGSTOP if we happend to attach
* just before the process takes a signal.
*/
if (!WIFSTOPPED(status)) {
fprintf(stderr,
"pid %u not stopped\n", pid);
detach(tcp, WSTOPSIG(status));
continue;
}
}
else {
#ifdef SUNOS4
/* A child of us stopped at exec */
if (WSTOPSIG(status) == SIGTRAP && followvfork)
fixvfork(tcp);
#endif /* SUNOS4 */
}
if (tcp->flags & TCB_BPTSET) {
if (clearbpt(tcp) < 0) /* Pretty fatal */ {
droptcb(tcp);
cleanup();
return -1;
}
}
goto tracing;
}
if (WSTOPSIG(status) != SIGTRAP) {
if (WSTOPSIG(status) == SIGSTOP &&
(tcp->flags & TCB_SIGTRAPPED)) {
/*
* Trapped attempt to block SIGTRAP
* Hope we are back in control now.
*/
tcp->flags &= ~(TCB_INSYSCALL | TCB_SIGTRAPPED);
if (ptrace(PTRACE_SYSCALL,
pid, (char *) 1, 0) < 0) {
perror("trace: ptrace(PTRACE_SYSCALL, ...)");
cleanup();
return -1;
}
continue;
}
if (!cflag
&& (qual_flags[WSTOPSIG(status)] & QUAL_SIGNAL)) {
printleader(tcp);
tprintf("--- %s (%s) ---",
signame(WSTOPSIG(status)),
strsignal(WSTOPSIG(status)));
printtrailer(tcp);
}
if ((tcp->flags & TCB_ATTACHED) &&
!sigishandled(tcp, WSTOPSIG(status))) {
detach(tcp, WSTOPSIG(status));
continue;
}
if (ptrace(PTRACE_SYSCALL, pid, (char *) 1,
WSTOPSIG(status)) < 0) {
perror("trace: ptrace(PTRACE_SYSCALL, ...)");
cleanup();
return -1;
}
tcp->flags &= ~TCB_SUSPENDED;
continue;
}
if (trace_syscall(tcp) < 0) {
if (tcp->flags & TCB_ATTACHED)
detach(tcp, 0);
else {
ptrace(PTRACE_KILL,
tcp->pid, (char *) 1, SIGTERM);
droptcb(tcp);
}
continue;
}
if (tcp->flags & TCB_EXITING) {
if (tcp->flags & TCB_ATTACHED)
detach(tcp, 0);
else if (ptrace(PTRACE_CONT, pid, (char *) 1, 0) < 0) {
perror("strace: ptrace(PTRACE_CONT, ...)");
cleanup();
return -1;
}
continue;
}
if (tcp->flags & TCB_SUSPENDED) {
if (!qflag)
fprintf(stderr, "Process %u suspended\n", pid);
continue;
}
tracing:
if (ptrace(PTRACE_SYSCALL, pid, (char *) 1, 0) < 0) {
perror("trace: ptrace(PTRACE_SYSCALL, ...)");
cleanup();
return -1;
}
}
return 0;
}
#endif /* !SVR4 */
static int curcol;
#ifdef __STDC__
#include <stdarg.h>
#define VA_START(a, b) va_start(a, b)
#else
#include <varargs.h>
#define VA_START(a, b) va_start(a)
#endif
void
#ifdef __STDC__
tprintf(const char *fmt, ...)
#else
tprintf(fmt, va_alist)
char *fmt;
va_dcl
#endif
{
va_list args;
VA_START(args, fmt);
if (outf)
curcol += vfprintf(outf, fmt, args);
va_end(args);
return;
}
void
printleader(tcp)
struct tcb *tcp;
{
if (tcp_last && (!outfname || followfork < 2 || tcp_last == tcp)) {
tcp_last->flags |= TCB_REPRINT;
tprintf(" <unfinished ...>\n");
}
curcol = 0;
if ((followfork == 1 || pflag_seen > 1) && outfname)
tprintf("%-5d ", tcp->pid);
else if (nprocs > 1 && !outfname)
tprintf("[pid %5u] ", tcp->pid);
if (tflag) {
char str[sizeof("HH:MM:SS")];
struct timeval tv, dtv;
static struct timeval otv;
gettimeofday(&tv, NULL);
if (rflag) {
if (otv.tv_sec == 0)
otv = tv;
tv_sub(&dtv, &tv, &otv);
tprintf("%6ld.%06ld ",
(long) dtv.tv_sec, (long) dtv.tv_usec);
otv = tv;
}
else if (tflag > 2) {
tprintf("%ld.%06ld ",
(long) tv.tv_sec, (long) tv.tv_usec);
}
else {
time_t local = tv.tv_sec;
strftime(str, sizeof(str), "%T", localtime(&local));
if (tflag > 1)
tprintf("%s.%06ld ", str, (long) tv.tv_usec);
else
tprintf("%s ", str);
}
}
if (iflag)
printcall(tcp);
}
void
tabto(col)
int col;
{
if (curcol < col)
tprintf("%*s", col - curcol, "");
}
void
printtrailer(tcp)
struct tcb *tcp;
{
tprintf("\n");
tcp_last = NULL;
}
#ifdef HAVE_MP_PROCFS
int mp_ioctl (int fd, int cmd, void *arg, int size) {
struct iovec iov[2];
int n = 1;
iov[0].iov_base = &cmd;
iov[0].iov_len = sizeof cmd;
if (arg) {
++n;
iov[1].iov_base = arg;
iov[1].iov_len = size;
}
return writev (fd, iov, n);
}
#endif