src/shared/binfmt-util.c

   1 #include <sys/stat.h>
   2 #include <sys/statvfs.h>
   3 #include <sys/vfs.h>
   4
   5 #include "binfmt-util.h"
   6 #include "fileio.h"
   7 #include "missing_magic.h"
   8 #include "stat-util.h"
   9
  10 int disable_binfmt(void) {
  11         int r;
  12
  13         /* Flush out all rules. This is important during shutdown to cover for rules using "F", since those
  14          * might pin a file and thus block us from unmounting stuff cleanly.
  15          *
  16          * We are a bit careful here, since binfmt_misc might still be an autofs which we don't want to
  17          * trigger. */
  18
  19         r = path_is_fs_type("/proc/sys/fs/binfmt_misc", BINFMTFS_MAGIC);
  20         if (r == 0 || r == -ENOENT) {
  21                 log_debug("binfmt_misc is not mounted, not detaching entries.");
  22                 return 0;
  23         }
  24         if (r < 0)
  25                 return log_warning_errno(r, "Failed to determine whether binfmt_misc is mounted: %m");
  26
  27         r = write_string_file("/proc/sys/fs/binfmt_misc/status", "-1", WRITE_STRING_FILE_DISABLE_BUFFER);
  28         if (r < 0)
  29                 return log_warning_errno(r, "Failed to unregister binfmt_misc entries: %m");
  30
  31         log_debug("Unregistered all remaining binfmt_misc entries.");
  32         return 0;
  33 }