OpenCloudOS-Kernel/fs
Pavel Emelyanov 893e26e61d userfaultfd: non-cooperative: Add fork() event
When the mm with uffd-ed vmas fork()-s the respective vmas notify their
uffds with the event which contains a descriptor with new uffd.  This
new descriptor can then be used to get events from the child and
populate its mm with data.  Note, that there can be different uffd-s
controlling different vmas within one mm, so first we should collect all
those uffds (and ctx-s) in a list and then notify them all one by one
but only once per fork().

The context is created at fork() time but the descriptor, file struct
and anon inode object is created at event read time.  So some trickery
is added to the userfaultfd_ctx_read() to handle the ctx queues' locking
vs file creation.

Another thing worth noticing is that the task that fork()-s waits for
the uffd event to get processed WITHOUT the mmap sem.

[aarcange@redhat.com: build warning fix]
  Link: http://lkml.kernel.org/r/20161216144821.5183-10-aarcange@redhat.com
Link: http://lkml.kernel.org/r/20161216144821.5183-9-aarcange@redhat.com
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22 16:41:28 -08:00
..
9p 9p: fix a potential acl leak 2017-02-22 16:41:27 -08:00
adfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
affs vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
afs afs: Use core kernel UUID generation 2017-02-10 16:34:17 +00:00
autofs4 Merge uncontroversial parts of branch 'readlink' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2016-12-17 19:16:12 -08:00
befs befs: add NFS export support 2016-12-22 11:25:24 +00:00
bfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
btrfs Merge branch 'for-4.11/next' into for-4.11/linus-merge 2017-02-17 14:08:19 -07:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
ceph ceph: fix bad endianness handling in parse_reply_info_extra 2017-01-18 17:58:45 +01:00
cifs CIFS: Allow to switch on encryption with seal mount option 2017-02-01 16:46:37 -06:00
coda vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
configfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
cramfs
crypto fscrypt: properly declare on-stack completion 2017-02-06 23:45:28 -05:00
debugfs debugfs: add debugfs_lookup() 2017-02-02 10:20:16 -07:00
devpts Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
dlm ktime: Get rid of ktime_equal() 2016-12-25 17:21:23 +01:00
ecryptfs vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
efivarfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
efs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
exofs locking/atomic, kref: Add kref_read() 2017-01-14 11:37:18 +01:00
exportfs exportfs: be careful to only return expected errors. 2016-10-06 09:07:44 -04:00
ext2 dax: fix build warnings with FS_DAX and !FS_IOMAP 2017-01-24 16:26:14 -08:00
ext4 mm, dax: change pmd_fault() to take only vmf parameter 2017-02-22 16:41:26 -08:00
f2fs Various cleanups for the file system encryption feature. 2017-02-20 18:22:31 -08:00
fat Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
freevxfs
fscache fscache: Fix dead object requeue 2017-01-31 13:23:09 -05:00
fuse Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 13:23:30 -08:00
gfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00
hfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hfsplus Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hostfs vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
hpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hugetlbfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
isofs Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block 2016-12-13 10:19:16 -08:00
jbd2 For this cycle we add support for the shutdown ioctl, which is 2017-02-20 18:24:39 -08:00
jffs2 vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
jfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
kernfs kernfs: handle null pointers while printing node name and path 2017-02-10 16:02:26 +01:00
lockd netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
minix vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
ncpfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
nfs pNFS: Fix a reference leak in _pnfs_return_layout 2017-01-26 15:50:41 -05:00
nfs_common netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
nfsd driver core patches for 4.11-rc1 2017-02-22 11:44:32 -08:00
nilfs2 block: Use pointer to backing_dev_info from request_queue 2017-02-02 08:20:48 -07:00
nls
notify Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-02-21 07:44:03 -08:00
ntfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ocfs2 ocfs2: fix deadlock issue when taking inode lock at vfs entry points 2017-02-22 16:41:27 -08:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
openpromfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
orangefs Merge uncontroversial parts of branch 'readlink' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2016-12-17 19:16:12 -08:00
overlayfs ovl: fix possible use after free on redirect dir lookup 2017-01-18 15:19:54 +01:00
proc Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-02-21 12:49:56 -08:00
pstore pstore: Check for prz allocation in walker 2017-02-13 10:25:52 -08:00
qnx4
qnx6
quota Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2016-12-19 08:23:53 -08:00
ramfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
reiserfs Merge uncontroversial parts of branch 'readlink' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2016-12-17 19:16:12 -08:00
romfs romfs: use different way to generate fsid for BLOCK or MTD 2017-01-24 16:26:14 -08:00
squashfs Merge uncontroversial parts of branch 'readlink' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2016-12-17 19:16:12 -08:00
sysfs Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2016-10-14 12:18:50 -07:00
sysv vfs: remove ".readlink = generic_readlink" assignments 2016-12-09 16:45:04 +01:00
tracefs fs: Replace CURRENT_TIME with current_time() for inode timestamps 2016-09-27 21:06:21 -04:00
ubifs Various cleanups for the file system encryption feature. 2017-02-20 18:22:31 -08:00
udf udf: simplify udf_ioctl() 2017-02-03 16:24:18 +01:00
ufs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
xfs mm, dax: change pmd_fault() to take only vmf parameter 2017-02-22 16:41:26 -08:00
Kconfig dax: fix build warnings with FS_DAX and !FS_IOMAP 2017-01-24 16:26:14 -08:00
Kconfig.binfmt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
Makefile logfs: remove from tree 2016-12-14 23:48:11 -05:00
aio.c aio: fix lock dep warning 2017-01-14 19:31:40 -05:00
anon_inodes.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
attr.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
bad_inode.c bad_inode: add missing i_op initializers 2016-12-09 11:57:43 +01:00
binfmt_aout.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
binfmt_elf.c fs/binfmt: Convert obsolete cputime type to nsecs 2017-02-01 09:13:51 +01:00
binfmt_elf_fdpic.c fs/binfmt: Convert obsolete cputime type to nsecs 2017-02-01 09:13:51 +01:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c fs: Replace current_fs_time() with current_time() 2016-09-27 21:06:22 -04:00
binfmt_script.c
block_dev.c Merge branch 'for-4.11/next' into for-4.11/linus-merge 2017-02-17 14:08:19 -07:00
buffer.c clean_bdev_aliases: Prevent cleaning blocks that are not in block range 2017-01-02 09:35:14 -07:00
char_dev.c
compat.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
compat_binfmt_elf.c fs/binfmt: Convert obsolete cputime type to nsecs 2017-02-01 09:13:51 +01:00
compat_ioctl.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
coredump.c coredump: Ensure proper size of sparse core files 2017-01-14 19:32:40 -05:00
dax.c mm, dax: change pmd_fault() to take only vmf parameter 2017-02-22 16:41:26 -08:00
dcache.c mnt: Protect the mountpoint hashtable with mount_lock 2017-01-10 13:34:43 +13:00
dcookies.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
direct-io.c do_direct_IO: Use inode->i_blkbits to compute block count to be cleaned 2017-01-10 13:29:54 -07:00
drop_caches.c
eventfd.c
eventpoll.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
exec.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
fcntl.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
fhandle.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
file.c fs/file: more unsigned file descriptors 2016-09-27 18:47:38 -04:00
file_table.c constify alloc_file() 2016-12-05 19:01:16 -05:00
filesystems.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
fs-writeback.c fs/fs-writeback.c: remove redundant if check 2016-12-12 18:55:08 -08:00
fs_pin.c
fs_struct.c
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
internal.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-12-17 18:44:00 -08:00
ioctl.c vfs: call vfs_clone_file_range() under freeze protection 2016-12-16 11:02:54 +01:00
iomap.c fs: break out of iomap_file_buffered_write on fatal signals 2017-02-03 14:13:19 -08:00
libfs.c libfs: Modify mount_pseudo_xattr to be clear it is not a userspace mount 2017-01-10 13:34:55 +13:00
locks.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mbcache.c mbcache: document that "find" functions only return reusable entries 2016-12-03 15:55:01 -05:00
mount.h vfs: add path_is_mountpoint() helper 2016-12-03 20:51:35 -05:00
mpage.c fs: Add helper to clean bdev aliases under a bh and use it 2016-11-04 14:34:47 -06:00
namei.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
namespace.c mnt: Protect the mountpoint hashtable with mount_lock 2017-01-10 13:34:43 +13:00
no-block.c
nsfs.c net: add an ioctl to get a socket network namespace 2016-10-31 10:56:36 -04:00
open.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pipe.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pnode.c reorganize do_make_slave() 2016-12-16 16:30:49 -05:00
pnode.h mnt: Add a per mount namespace limit on the number of mounts 2016-09-30 12:46:48 -05:00
posix_acl.c tmpfs: clear S_ISGID when setting posix ACLs 2017-01-10 01:29:48 -05:00
proc_namespace.c
read_write.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
readdir.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
select.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
seq_file.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
signalfd.c
splice.c vfs: fix uninitialized flags in splice_to_pipe() 2017-02-16 09:09:02 -08:00
stack.c
stat.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
statfs.c vfs: misc struct path constification 2016-12-05 19:03:49 -05:00
super.c block: Use pointer to backing_dev_info from request_queue 2017-02-02 08:20:48 -07:00
sync.c
timerfd.c timerfd: Protect the might cancel mechanism proper 2017-02-10 11:15:09 +01:00
userfaultfd.c userfaultfd: non-cooperative: Add fork() event 2017-02-22 16:41:28 -08:00
utimes.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
xattr.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00