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Misc #14907 » 0001-io.c-do-not-close-inherited-FDs-by-default.patch

normalperson (Eric Wong), 07/11/2018 10:33 AM

View differences:

io.c
int8_t init_p, next_p, binmode;
};
static rb_atomic_t max_file_descriptor = NOFILE;
void
rb_update_max_fd(int fd)
{
struct stat buf;
rb_atomic_t afd = (rb_atomic_t)fd;
rb_atomic_t max_fd = max_file_descriptor;
if (afd <= max_fd)
return;
if (fstat(fd, &buf) != 0 && errno == EBADF) {
rb_bug("rb_update_max_fd: invalid fd (%d) given.", fd);
}
while (max_fd < afd) {
max_fd = ATOMIC_CAS(max_file_descriptor, max_fd, afd);
}
/* noop */
}
void
......
}
}
#if defined(__linux__)
/* Linux /proc/self/status contains a line: "FDSize:\t<nnn>\n"
* Since /proc may not be available, linux_get_maxfd is just a hint.
* This function, linux_get_maxfd, must be async-signal-safe.
* I.e. opendir() is not usable.
*
* Note that memchr() and memcmp is *not* async-signal-safe in POSIX.
* However they are easy to re-implement in async-signal-safe manner.
* (Also note that there is missing/memcmp.c.)
*/
static int
linux_get_maxfd(void)
{
int fd;
char buf[4096], *p, *np, *e;
ssize_t ss;
fd = rb_cloexec_open("/proc/self/status", O_RDONLY|O_NOCTTY, 0);
if (fd == -1) return -1;
ss = read(fd, buf, sizeof(buf));
if (ss == -1) goto err;
p = buf;
e = buf + ss;
while ((int)sizeof("FDSize:\t0\n")-1 <= e-p &&
(np = memchr(p, '\n', e-p)) != NULL) {
if (memcmp(p, "FDSize:", sizeof("FDSize:")-1) == 0) {
int fdsize;
p += sizeof("FDSize:")-1;
*np = '\0';
fdsize = (int)ruby_strtoul(p, (char **)NULL, 10);
close(fd);
return fdsize;
}
p = np+1;
}
/* fall through */
err:
close(fd);
return -1;
}
#endif
/* This function should be async-signal-safe. */
void
rb_close_before_exec(int lowfd, int maxhint, VALUE noclose_fds)
{
#if defined(HAVE_FCNTL) && defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
int fd, ret;
int max = (int)max_file_descriptor;
# ifdef F_MAXFD
/* F_MAXFD is available since NetBSD 2.0. */
ret = fcntl(0, F_MAXFD); /* async-signal-safe */
if (ret != -1)
maxhint = max = ret;
# elif defined(__linux__)
ret = linux_get_maxfd();
if (maxhint < ret)
maxhint = ret;
/* maxhint = max = ret; if (ret == -1) abort(); // test */
# endif
if (max < maxhint)
max = maxhint;
for (fd = lowfd; fd <= max; fd++) {
if (!NIL_P(noclose_fds) &&
RTEST(rb_hash_lookup(noclose_fds, INT2FIX(fd)))) /* async-signal-safe */
continue;
ret = fcntl(fd, F_GETFD); /* async-signal-safe */
if (ret != -1 && !(ret & FD_CLOEXEC)) {
fcntl(fd, F_SETFD, ret|FD_CLOEXEC); /* async-signal-safe */
}
# define CONTIGUOUS_CLOSED_FDS 20
if (ret != -1) {
if (max < fd + CONTIGUOUS_CLOSED_FDS)
max = fd + CONTIGUOUS_CLOSED_FDS;
}
}
#endif
/* no-op */
}
static int
test/lib/test/unit.rb
r.close if r
nil
else
r.close_on_exec = true
r.close_on_exec = true
@jobserver = [r, w]
options[:parallel] ||= 1
end
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