#endif /* MIPS */
#endif /* SVR4 */
+static int
+set_cloexec_flag(int fd)
+{
+ int flags, newflags;
+
+ if ((flags = fcntl(fd, F_GETFD, 0)) < 0)
+ {
+ fprintf(stderr, "%s: fcntl F_GETFD: %s\n",
+ progname, strerror(errno));
+ return -1;
+ }
+
+ newflags = flags | FD_CLOEXEC;
+ if (flags == newflags)
+ return 0;
+
+ if (fcntl(fd, F_SETFD, newflags) < 0)
+ {
+ fprintf(stderr, "%s: fcntl F_SETFD: %s\n",
+ progname, strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * When strace is setuid executable, we have to swap uids
+ * before and after filesystem and process management operations.
+ */
+static void
+swap_uid(void)
+{
+#ifndef SVR4
+ int euid = geteuid(), uid = getuid();
+
+ if (euid != uid && setreuid(euid, uid) < 0)
+ {
+ fprintf(stderr, "%s: setreuid: %s\n",
+ progname, strerror(errno));
+ exit(1);
+ }
+#endif
+}
+
+static FILE *
+strace_fopen(const char *path, const char *mode)
+{
+ FILE *fp;
+
+ swap_uid();
+ if ((fp = fopen(path, mode)) == NULL)
+ fprintf(stderr, "%s: can't fopen '%s': %s\n",
+ progname, path, strerror(errno));
+ swap_uid();
+ if (fp && set_cloexec_flag(fileno(fp)) < 0)
+ {
+ fclose(fp);
+ fp = NULL;
+ }
+ return fp;
+}
+
+static int popen_pid = -1;
+
+#ifndef _PATH_BSHELL
+# define _PATH_BSHELL "/bin/sh"
+#endif
+
+/*
+ * We cannot use standard popen(3) here because we have to distinguish
+ * popen child process from other processes we trace, and standard popen(3)
+ * does not export its child's pid.
+ */
+static FILE *
+strace_popen(const char *command)
+{
+ int fds[2];
+
+ swap_uid();
+ if (pipe(fds) < 0)
+ {
+ fprintf(stderr, "%s: pipe: %s\n",
+ progname, strerror(errno));
+ swap_uid();
+ return NULL;
+ }
+
+ if (set_cloexec_flag(fds[1]) < 0)
+ {
+ close(fds[0]);
+ close(fds[1]);
+ swap_uid();
+ return NULL;
+ }
+
+ if ((popen_pid = fork()) == -1)
+ {
+ fprintf(stderr, "%s: fork: %s\n",
+ progname, strerror(errno));
+ close(fds[0]);
+ close(fds[1]);
+ swap_uid();
+ return NULL;
+ }
+
+ if (popen_pid)
+ {
+ /* parent */
+ close(fds[0]);
+ swap_uid();
+ return fdopen(fds[1], "w");
+ } else
+ {
+ /* child */
+ close(fds[1]);
+ if (fds[0] && (dup2(fds[0], 0) || close(fds[0])))
+ {
+ fprintf(stderr, "%s: dup2: %s\n",
+ progname, strerror(errno));
+ _exit(1);
+ }
+ execl(_PATH_BSHELL, "sh", "-c", command, NULL);
+ fprintf(stderr, "%s: execl: %s: %s\n",
+ progname, _PATH_BSHELL, strerror(errno));
+ _exit(1);
+ }
+}
+
+static int
+newoutf(struct tcb *tcp)
+{
+ if (outfname && followfork > 1) {
+ char name[MAXPATHLEN];
+ FILE *fp;
+
+ sprintf(name, "%s.%u", outfname, tcp->pid);
+ if ((fp = strace_fopen(name, "w")) == NULL)
+ return -1;
+ tcp->outf = fp;
+ }
+ return 0;
+}
+
int
main(argc, argv)
int argc;
fprintf(stderr, "%s: I'm sorry, I can't let you do that, Dave.\n", progname);
break;
}
- if ((tcp = alloctcb(pid)) == NULL) {
+ if ((tcp = alloc_tcb(pid, 0)) == NULL) {
fprintf(stderr, "%s: out of memory\n",
progname);
exit(1);
run_gid = getgid();
}
-#ifndef SVR4
- setreuid(geteuid(), getuid());
-#endif
-
/* Check if they want to redirect the output. */
if (outfname) {
- long f;
-
/* See if they want to pipe the output. */
if (outfname[0] == '|' || outfname[0] == '!') {
/*
exit(1);
}
- if ((outf = popen(outfname + 1, "w")) == NULL) {
- fprintf(stderr, "%s: can't popen '%s': %s\n",
- progname, outfname + 1,
- strerror(errno));
+ if ((outf = strace_popen(outfname + 1)) == NULL)
exit(1);
- }
- }
- else if ((outf = fopen(outfname, "w")) == NULL) {
- fprintf(stderr, "%s: can't fopen '%s': %s\n",
- progname, outfname, strerror(errno));
- exit(1);
}
-
- if ((f=fcntl(fileno(outf), F_GETFD)) < 0 ) {
- perror("failed to get flags for outputfile");
- exit(1);
- }
-
- if (fcntl(fileno(outf), F_SETFD, f|FD_CLOEXEC) < 0 ) {
- perror("failed to set flags for outputfile");
+ else if (followfork <= 1 &&
+ (outf = strace_fopen(outfname, "w")) == NULL)
exit(1);
- }
}
-#ifndef SVR4
- setreuid(geteuid(), getuid());
-#endif
-
if (!outfname || outfname[0] == '|' || outfname[0] == '!')
setvbuf(outf, buf, _IOLBF, BUFSIZ);
if (outfname && optind < argc) {
for (c = 0; c < tcbtabsize; c++) {
tcp = tcbtab[c];
- /* Reinitialize the output since it may have changed. */
- tcp->outf = outf;
if (!(tcp->flags & TCB_INUSE) || !(tcp->flags & TCB_ATTACHED))
continue;
+#ifdef LINUX
+ if (tcp->flags & TCB_CLONE_THREAD)
+ continue;
+#endif
+ /* Reinitialize the output since it may have changed. */
+ tcp->outf = outf;
+ if (newoutf(tcp) < 0)
+ exit(1);
+
#ifdef USE_PROCFS
if (proc_open(tcp, 1) < 0) {
fprintf(stderr, "trouble opening proc file\n");
}
#else /* !USE_PROCFS */
# ifdef LINUX
- if (tcp->flags & TCB_CLONE_THREAD)
- continue;
if (followfork) {
char procdir[MAXPATHLEN];
DIR *dir;
+
sprintf(procdir, "/proc/%d/task", tcp->pid);
dir = opendir(procdir);
if (dir != NULL) {
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;
-}
-
int
expand_tcbtab()
{
struct tcb *
-alloctcb(pid)
-int pid;
+alloc_tcb(int pid, int command_options_parsed)
{
int i;
struct tcb *tcp;
tcp->stime.tv_usec = 0;
tcp->pfd = -1;
nprocs++;
+ if (command_options_parsed)
+ newoutf(tcp);
return tcp;
}
}
- fprintf(stderr, "%s: alloctcb: tcb table full\n", progname);
+ fprintf(stderr, "%s: alloc_tcb: tcb table full\n", progname);
return NULL;
}
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");
+ if (set_cloexec_flag(tcp->pfd) < 0) {
return -1;
}
sprintf(proc, "/proc/%d/status", tcp->pid);
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");
+ if (set_cloexec_flag(tcp->pfd_stat) < 0) {
return -1;
}
sprintf(proc, "/proc/%d/as", tcp->pid);
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");
+ if (set_cloexec_flag(tcp->pfd_as) < 0) {
return -1;
}
#else
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");
+ if (set_cloexec_flag(tcp->pfd) < 0) {
return -1;
}
#endif
static void
proc_poll_open()
{
- int arg;
int i;
if (pipe(proc_poll_pipe) < 0) {
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");
+ if (set_cloexec_flag(proc_poll_pipe[i]) < 0) {
exit(1);
}
}
return -1;
}
}
+ if (pid == popen_pid) {
+ if (WIFEXITED(status) || WIFSIGNALED(status))
+ popen_pid = -1;
+ continue;
+ }
if (debug)
fprintf(stderr, " [wait(%#x) = %u]\n", status, pid);
return 0;
}
tcp->flags |= TCB_ATTACHED | TCB_SUSPENDED;
- newoutf(tcp);
if (!qflag)
fprintf(stderr, "\
Process %d attached (waiting for parent)\n",
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