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Make set_cloexec_flag abort on error

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set_cloexec_flag() may fail only if we pass it a bad fd,
such as -1 or non-opened one. If we do, we have a bug
in the caller. It makes no sense to try to continue
running when we detect such a blatant bug in our own code.

* strace (set_cloexec_flag): Abort instead of returning error
  indicator. Change function to return void.
  (strace_fopen): Remove error check on set_cloexec_flag return value.
  (proc_open): Likewise.
  (proc_poll_open): Likewise.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
This commit is contained in:
Denys Vlasenko 2011-06-22 13:11:23 +02:00
parent 7dd23384f7
commit 1f532ab27d
1 changed files with 19 additions and 36 deletions
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55
strace.c
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@ -285,30 +285,26 @@ foobar()
# define fork() vfork()
#endif
static int
static void
set_cloexec_flag(int fd)
{
int flags, newflags;
int flags, newflags;
if ((flags = fcntl(fd, F_GETFD, 0)) < 0)
{
fprintf(stderr, "%s: fcntl F_GETFD: %s\n",
progname, strerror(errno));
return -1;
flags = fcntl(fd, F_GETFD);
if (flags < 0) {
/* Can happen only if fd is bad.
* Should never happen: if it does, we have a bug
* in the caller. Therefore we just abort
* instead of propagating the error.
*/
perror_msg_and_die("fcntl(%d, F_GETFD)", fd);
}
newflags = flags | FD_CLOEXEC;
if (flags == newflags)
return 0;
return;
if (fcntl(fd, F_SETFD, newflags) < 0)
{
fprintf(stderr, "%s: fcntl F_SETFD: %s\n",
progname, strerror(errno));
return -1;
}
return 0;
fcntl(fd, F_SETFD, newflags); /* never fails */
}
/*
@ -346,11 +342,8 @@ strace_fopen(const char *path, const char *mode)
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;
}
if (fp)
set_cloexec_flag(fileno(fp));
return fp;
}
@ -1287,25 +1280,19 @@ proc_open(struct tcb *tcp, int attaching)
perror("strace: open(\"/proc/...\", ...)");
return -1;
}
if (set_cloexec_flag(tcp->pfd) < 0) {
return -1;
}
set_cloexec_flag(tcp->pfd);
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 (set_cloexec_flag(tcp->pfd_stat) < 0) {
return -1;
}
set_cloexec_flag(tcp->pfd_stat);
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 (set_cloexec_flag(tcp->pfd_as) < 0) {
return -1;
}
set_cloexec_flag(tcp->pfd_as);
#else
/* Open the process pseudo-file in /proc. */
#ifndef FREEBSD
@ -1319,9 +1306,7 @@ proc_open(struct tcb *tcp, int attaching)
perror("strace: open(\"/proc/...\", ...)");
return -1;
}
if (set_cloexec_flag(tcp->pfd) < 0) {
return -1;
}
set_cloexec_flag(tcp->pfd);
#endif
#ifdef FREEBSD
sprintf(proc, "/proc/%d/regs", tcp->pid);
@ -1931,9 +1916,7 @@ proc_poll_open(void)
exit(1);
}
for (i = 0; i < 2; i++) {
if (set_cloexec_flag(proc_poll_pipe[i]) < 0) {
exit(1);
}
set_cloexec_flag(proc_poll_pipe[i]);
}
}