LXR linux/tools/perf/trace/beauty/mount

   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
   8#include "trace/beauty/beauty.h"
   9#include <linux/compiler.h>
  10#include <linux/kernel.h>
  11#include <linux/log2.h>
  12#include <sys/mount.h>
  13
  14static size_t mount__scnprintf_flags(unsigned long flags, char *bf, size_t size, bool show_prefix)
  15{
  16#include "trace/beauty/generated/mount_flags_array.c"
  17        static DEFINE_STRARRAY(mount_flags, "MS_");
  18
  19        return strarray__scnprintf_flags(&strarray__mount_flags, bf, size, show_prefix, flags);
  20}
  21
  22unsigned long syscall_arg__mask_val_mount_flags(struct syscall_arg *arg __maybe_unused, unsigned long flags)
  23{
  24        // do_mount in fs/namespace.c:
  25        /*
  26         * Pre-0.97 versions of mount() didn't have a flags word.  When the
  27         * flags word was introduced its top half was required to have the
  28         * magic value 0xC0ED, and this remained so until 2.4.0-test9.
  29         * Therefore, if this magic number is present, it carries no
  30         * information and must be discarded.
  31         */
  32        if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
  33                flags &= ~MS_MGC_MSK;
  34
  35        return flags;
  36}
  37
  38size_t syscall_arg__scnprintf_mount_flags(char *bf, size_t size, struct syscall_arg *arg)
  39{
  40        unsigned long flags = arg->val;
  41
  42        return mount__scnprintf_flags(flags, bf, size, arg->show_string_prefix);
  43}
  44