| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <sys/stat.h> |
| #include <sys/statvfs.h> |
| #include <sys/vfs.h> |
| |
| #include "binfmt-util.h" |
| #include "errno-util.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "fs-util.h" |
| #include "missing_magic.h" |
| #include "stat-util.h" |
| |
| int binfmt_mounted(void) { |
| _cleanup_close_ int fd = -EBADF; |
| int r; |
| |
| fd = RET_NERRNO(open("/proc/sys/fs/binfmt_misc", O_CLOEXEC | O_DIRECTORY | O_PATH)); |
| if (fd == -ENOENT) |
| return false; |
| if (fd < 0) |
| return fd; |
| |
| r = fd_is_fs_type(fd, BINFMTFS_MAGIC); |
| if (r <= 0) |
| return r; |
| |
| return access_fd(fd, W_OK) >= 0; |
| } |
| |
| int disable_binfmt(void) { |
| int r; |
| |
| /* Flush out all rules. This is important during shutdown to cover for rules using "F", since those |
| * might pin a file and thus block us from unmounting stuff cleanly. |
| * |
| * We are a bit careful here, since binfmt_misc might still be an autofs which we don't want to |
| * trigger. */ |
| |
| r = binfmt_mounted(); |
| if (r < 0) |
| return log_warning_errno(r, "Failed to determine whether binfmt_misc is mounted: %m"); |
| if (r == 0) { |
| log_debug("binfmt_misc is not mounted in read-write mode, not detaching entries."); |
| return 0; |
| } |
| |
| r = write_string_file("/proc/sys/fs/binfmt_misc/status", "-1", WRITE_STRING_FILE_DISABLE_BUFFER); |
| if (r < 0) |
| return log_warning_errno(r, "Failed to unregister binfmt_misc entries: %m"); |
| |
| log_debug("Unregistered all remaining binfmt_misc entries."); |
| return 0; |
| } |