linux/fs
Nishanth Aravamudan 457c1b27ed hugetlb: ensure hugepage access is denied if hugepages are not supported
Currently, I am seeing the following when I `mount -t hugetlbfs /none
/dev/hugetlbfs`, and then simply do a `ls /dev/hugetlbfs`.  I think it's
related to the fact that hugetlbfs is properly not correctly setting
itself up in this state?:

  Unable to handle kernel paging request for data at address 0x00000031
  Faulting instruction address: 0xc000000000245710
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  ....

In KVM guests on Power, in a guest not backed by hugepages, we see the
following:

  AnonHugePages:         0 kB
  HugePages_Total:       0
  HugePages_Free:        0
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:         64 kB

HPAGE_SHIFT == 0 in this configuration, which indicates that hugepages
are not supported at boot-time, but this is only checked in
hugetlb_init().  Extract the check to a helper function, and use it in a
few relevant places.

This does make hugetlbfs not supported (not registered at all) in this
environment.  I believe this is fine, as there are no valid hugepages
and that won't change at runtime.

[akpm@linux-foundation.org: use pr_info(), per Mel]
[akpm@linux-foundation.org: fix build when HPAGE_SHIFT is undefined]
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:58 -07:00
..
9p mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
adfs fs/adfs/super.c: add __init to init_inodecache() 2014-04-07 16:36:08 -07:00
affs affs: add mount option to avoid filename truncates 2014-04-07 16:36:08 -07:00
afs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
autofs4 autofs4: check dev ioctl size before allocating 2014-04-08 16:48:51 -07:00
befs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
bfs fs/bfs/inode.c: add __init to init_inodecache() 2014-04-07 16:36:08 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-04-27 13:26:28 -07:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2014-05-05 15:17:02 -07:00
cifs cif: fix dead code 2014-04-16 23:08:57 -05:00
coda Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
configfs configfs: fix race between dentry put and lookup 2013-11-21 16:42:27 -08:00
cramfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
debugfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
devpts fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
dlm net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
ecryptfs Merge branch 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2014-04-04 14:03:05 -07:00
efivarfs efivarfs: 'efivarfs_file_write' function reorganization 2014-03-04 16:16:16 +00:00
efs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
exofs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2014-04-10 14:33:02 -07:00
exportfs
ext2 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
ext4 These are regression and bug fixes for ext4. 2014-04-20 20:43:47 -07:00
f2fs Merge branch 'akpm' (incoming from Andrew) 2014-04-07 16:38:06 -07:00
fat Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
freevxfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
fscache FS-Cache: Handle removal of unadded object to the fscache_object_list rb tree 2014-02-17 13:47:35 -08:00
fuse fuse: add renameat2 support 2014-04-28 16:43:44 +02:00
gfs2 mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
hfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
hfsplus Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
hostfs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
hpfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
hppfs
hugetlbfs hugetlb: ensure hugepage access is denied if hugepages are not supported 2014-05-06 13:04:58 -07:00
isofs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
jbd jbd: Revise KERN_EMERG error messages 2013-12-04 12:27:46 +01:00
jbd2 jbd2: improve error messages for inconsistent journal heads 2014-03-12 16:38:03 -04:00
jffs2 MTD updates for 3.15: 2014-04-07 10:17:30 -07:00
jfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
kernfs kernfs: add back missing error check in kernfs_fop_mmap() 2014-04-25 12:25:13 -07:00
lockd lockd: ensure we tear down any live sockets when socket creation fails during lockd_up 2014-03-28 10:43:08 -04:00
logfs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
minix Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
ncpfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
nfs mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
nfs_common
nfsd Revert "nfsd4: fix nfs4err_resource in 4.1 case" 2014-04-18 14:46:45 +02:00
nilfs2 mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
nls nls: have register_nls() set ->owner 2014-01-25 03:14:05 -05:00
notify fanotify: move unrelated handling from copy_event_to_user() 2014-04-03 16:20:51 -07:00
ntfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
ocfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
omfs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
openpromfs fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
proc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
pstore Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
qnx4 fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
qnx6 fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
quota Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
ramfs fs/ramfs: move ramfs_aops to inode.c 2014-01-23 16:36:58 -08:00
reiserfs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
romfs fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
squashfs fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
sysfs sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner() 2014-04-16 11:56:33 -07:00
sysv Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
ubifs UBIFS: fix remount error path 2014-05-05 09:31:33 +03:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
ufs fs/ufs: remove unused ufs_super_block_third pointer 2014-04-07 16:36:16 -07:00
xfs These are regression and bug fixes for ext4. 2014-04-20 20:43:47 -07:00
aio.c aio: fix potential leak in aio_run_iocb(). 2014-05-01 08:37:43 -04:00
anon_inodes.c vfs: Allocate anon_inode_inode in anon_inode_init() 2014-03-27 09:52:54 -07:00
attr.c fs: fix iversion handling 2013-12-05 16:36:21 -06:00
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c exec: kill the unnecessary mm->def_flags setting in load_elf_binary() 2014-04-07 16:35:52 -07:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c binfmt_misc: add missing 'break' statement 2014-04-03 16:21:16 -07:00
binfmt_script.c
binfmt_som.c
bio-integrity.c block: Ensure we only enable integrity metadata for reads and writes 2014-04-09 08:00:06 -06:00
bio.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
block_dev.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
char_dev.c
compat_binfmt_elf.c binfmt_elf: add ELF_HWCAP2 to compat auxv entries 2014-03-04 08:05:21 +00:00
compat_ioctl.c fs/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types 2014-03-06 16:30:44 +01:00
compat.c locks: rename file-private locks to "open file description locks" 2014-04-22 08:23:58 -04:00
coredump.c coredump: fix va_list corruption 2014-04-19 13:23:31 -07:00
dcache.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-04-08 09:52:16 -07:00
dcookies.c fs/compat: fix lookup_dcookie() parameter handling 2014-01-29 16:22:40 -08:00
direct-io.c xfs: update for 3.15-rc1 2014-04-04 15:50:08 -07:00
drop_caches.c drop_caches: add some documentation and info message 2014-04-03 16:21:04 -07:00
eventfd.c eventfd_ctx_fdget(): use fdget() instead of fget() 2014-01-25 03:13:04 -05:00
eventpoll.c epoll: do not take the nested ep->mtx on EPOLL_CTL_DEL 2014-01-02 14:40:30 -08:00
exec.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
fcntl.c locks: rename file-private locks to "open file description locks" 2014-04-22 08:23:58 -04:00
fhandle.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
filesystems.c sys_sysfs: Add CONFIG_SYSFS_SYSCALL 2014-04-03 16:21:05 -07:00
fs_struct.c
fs-writeback.c One of the main highlights this time, is not the patches themselves 2014-04-04 14:49:16 -07:00
inode.c Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
internal.h
ioctl.c
ioprio.c
Kconfig kernfs: add CONFIG_KERNFS 2014-02-07 16:08:57 -08:00
Kconfig.binfmt
libfs.c consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
locks.c locks: rename FL_FILE_PVT and IS_FILE_PVT to use "*_OFDLCK" instead 2014-04-23 16:17:03 -04:00
Makefile kernfs: add CONFIG_KERNFS 2014-02-07 16:08:57 -08:00
mbcache.c ext4: each filesystem creates and uses its own mb_cache 2014-03-18 19:24:49 -04:00
mount.h reduce m_start() cost... 2014-04-01 23:19:09 -04:00
mpage.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
namei.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
namespace.c VFS: Make delayed_free() call free_vfsmnt() 2014-04-01 23:19:18 -04:00
no-block.c
open.c These are regression and bug fixes for ext4. 2014-04-20 20:43:47 -07:00
pipe.c switch pipe_read() to copy_page_to_iter() 2014-04-01 23:19:22 -04:00
pnode.c smarter propagate_mnt() 2014-04-01 23:19:08 -04:00
pnode.h smarter propagate_mnt() 2014-04-01 23:19:08 -04:00
posix_acl.c One of the main highlights this time, is not the patches themselves 2014-04-04 14:49:16 -07:00
proc_namespace.c reduce m_start() cost... 2014-04-01 23:19:09 -04:00
read_write.c Merge branch 'compat' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-03-31 14:32:17 -07:00
readdir.c
select.c
seq_file.c seq_file: always clear m->count when we free m->buf 2013-11-18 19:07:53 -08:00
signalfd.c
splice.c switch vmsplice_to_user() to copy_page_to_iter() 2014-04-01 23:19:23 -04:00
stack.c
stat.c
statfs.c
super.c fs: Don't return 0 from get_anon_bdev 2014-04-16 11:53:08 -07:00
sync.c Revert "writeback: do not sync data dirtied after sync start" 2014-02-22 02:02:28 +01:00
timerfd.c timerfd: support CLOCK_BOOTTIME clock 2014-01-23 16:57:40 -08:00
utimes.c
xattr.c