Revert "libpam/pam_modutil_sanitize.c: optimize the way to close fds"

This reverts commit 1b087edc7f05237bf5eccc405704cd82b848e761.

1 files changed, 14 insertions, 59 deletions

diff --git a/libpam/pam_modutil_sanitize.c b/libpam/pam_modutil_sanitize.c
index 58b9537c..7579c5bd 100644
--- a/libpam/pam_modutil_sanitize.c
+++ b/libpam/pam_modutil_sanitize.c
@@ -10,13 +10,6 @@
 #include <fcntl.h>
 #include <syslog.h>
 #include <sys/resource.h>
-#include <dirent.h>
-#ifdef HAVE_SYS_VFS_H
-#include <sys/vfs.h>
-#endif
-#ifdef HAVE_LINUX_MAGIC_H
-#include <linux/magic.h>
-#endif
 
 /*
  * Creates a pipe, closes its write end, redirects fd to its read end.
@@ -91,69 +84,31 @@ redirect_out(pam_handle_t *pamh, enum pam_modutil_redirect_fd mode,
 	return fd;
 }
 
-/* Check if path is in a procfs. */
-static int
-is_in_procfs(int fd)
-{
-#if defined HAVE_SYS_VFS_H && defined PROC_SUPER_MAGIC
-	struct statfs stfs;
-
-	if (fstatfs(fd, &stfs) == 0) {
-		if (stfs.f_type == PROC_SUPER_MAGIC)
-			return 1;
-	} else {
-		return 0;
-	}
-#endif /* HAVE_SYS_VFS_H && PROC_SUPER_MAGIC */
-
-	return -1;
-}
-
 /* Closes all descriptors after stderr. */
 static void
 close_fds(void)
 {
-	DIR *dir = NULL;
-	struct dirent *dent;
-	int dfd = -1;
-	int fd;
-	struct rlimit rlim;
-
 	/*
 	 * An arbitrary upper limit for the maximum file descriptor number
 	 * returned by RLIMIT_NOFILE.
 	 */
-	const unsigned int MAX_FD_NO = 65535;
+	const int MAX_FD_NO = 65535;
 
 	/* The lower limit is the same as for _POSIX_OPEN_MAX. */
-	const unsigned int MIN_FD_NO = 20;
-
-	/* If /proc is mounted, we can optimize which fd can be closed. */
-	if ((dir = opendir("/proc/self/fd")) != NULL) {
-		if ((dfd = dirfd(dir)) >= 0 && is_in_procfs(dfd) > 0) {
-			while ((dent = readdir(dir)) != NULL) {
-				fd = atoi(dent->d_name);
-				if (fd > STDERR_FILENO && fd != dfd)
-					close(fd);
-			}
-		} else {
-			dfd = -1;
-		}
-		closedir(dir);
-	}
+	const int MIN_FD_NO = 20;
 
-	/* If /proc isn't available, fallback to the previous behavior. */
-	if (dfd < 0) {
-		if (getrlimit(RLIMIT_NOFILE, &rlim) || rlim.rlim_max > MAX_FD_NO)
-			fd = MAX_FD_NO;
-		else if (rlim.rlim_max < MIN_FD_NO)
-			fd = MIN_FD_NO;
-		else
-			fd = rlim.rlim_max - 1;
-
-		for (; fd > STDERR_FILENO; --fd)
-			close(fd);
-	}
+	int fd;
+	struct rlimit rlim;
+
+	if (getrlimit(RLIMIT_NOFILE, &rlim) || rlim.rlim_max > MAX_FD_NO)
+		fd = MAX_FD_NO;
+	else if (rlim.rlim_max < MIN_FD_NO)
+		fd = MIN_FD_NO;
+	else
+		fd = rlim.rlim_max - 1;
+
+	for (; fd > STDERR_FILENO; --fd)
+		close(fd);
 }
 
 int