mount_flags.c 1.3 KB

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  1. // SPDX-License-Identifier: LGPL-2.1
  2. /*
  3. * trace/beauty/mount_flags.c
  4. *
  5. * Copyright (C) 2018, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
  6. */
  7. #include "trace/beauty/beauty.h"
  8. #include <linux/compiler.h>
  9. #include <linux/kernel.h>
  10. #include <linux/log2.h>
  11. #include <sys/mount.h>
  12. static size_t mount__scnprintf_flags(unsigned long flags, char *bf, size_t size, bool show_prefix)
  13. {
  14. #include "trace/beauty/generated/mount_flags_array.c"
  15. static DEFINE_STRARRAY(mount_flags, "MS_");
  16. return strarray__scnprintf_flags(&strarray__mount_flags, bf, size, show_prefix, flags);
  17. }
  18. unsigned long syscall_arg__mask_val_mount_flags(struct syscall_arg *arg __maybe_unused, unsigned long flags)
  19. {
  20. // do_mount in fs/namespace.c:
  21. /*
  22. * Pre-0.97 versions of mount() didn't have a flags word. When the
  23. * flags word was introduced its top half was required to have the
  24. * magic value 0xC0ED, and this remained so until 2.4.0-test9.
  25. * Therefore, if this magic number is present, it carries no
  26. * information and must be discarded.
  27. */
  28. if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
  29. flags &= ~MS_MGC_MSK;
  30. return flags;
  31. }
  32. size_t syscall_arg__scnprintf_mount_flags(char *bf, size_t size, struct syscall_arg *arg)
  33. {
  34. unsigned long flags = arg->val;
  35. return mount__scnprintf_flags(flags, bf, size, arg->show_string_prefix);
  36. }