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 14 static 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 22 unsigned 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 38 size_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