Eric W. Biederman 381ca1fba9 proc: Allow proc_free_inum to be called from any context ... While testing the pid namespace code I hit this nasty warning. [ 176.262617] ------------[ cut here ]------------ [ 176.263388] WARNING: at /home/eric/projects/linux/linux-userns-devel/kernel/softirq.c:160 local_bh_enable_ip+0x7a/0xa0() [ 176.265145] Hardware name: Bochs [ 176.265677] Modules linked in: [ 176.266341] Pid: 742, comm: bash Not tainted 3.7.0userns+ #18 [ 176.266564] Call Trace: [ 176.266564] [<ffffffff810a539f>] warn_slowpath_common+0x7f/0xc0 [ 176.266564] [<ffffffff810a53fa>] warn_slowpath_null+0x1a/0x20 [ 176.266564] [<ffffffff810ad9ea>] local_bh_enable_ip+0x7a/0xa0 [ 176.266564] [<ffffffff819308c9>] _raw_spin_unlock_bh+0x19/0x20 [ 176.266564] [<ffffffff8123dbda>] proc_free_inum+0x3a/0x50 [ 176.266564] [<ffffffff8111d0dc>] free_pid_ns+0x1c/0x80 [ 176.266564] [<ffffffff8111d195>] put_pid_ns+0x35/0x50 [ 176.266564] [<ffffffff810c608a>] put_pid+0x4a/0x60 [ 176.266564] [<ffffffff8146b177>] tty_ioctl+0x717/0xc10 [ 176.266564] [<ffffffff810aa4d5>] ? wait_consider_task+0x855/0xb90 [ 176.266564] [<ffffffff81086bf9>] ? default_spin_lock_flags+0x9/0x10 [ 176.266564] [<ffffffff810cab0a>] ? remove_wait_queue+0x5a/0x70 [ 176.266564] [<ffffffff811e37e8>] do_vfs_ioctl+0x98/0x550 [ 176.266564] [<ffffffff810b8a0f>] ? recalc_sigpending+0x1f/0x60 [ 176.266564] [<ffffffff810b9127>] ? __set_task_blocked+0x37/0x80 [ 176.266564] [<ffffffff810ab95b>] ? sys_wait4+0xab/0xf0 [ 176.266564] [<ffffffff811e3d31>] sys_ioctl+0x91/0xb0 [ 176.266564] [<ffffffff810a95f0>] ? task_stopped_code+0x50/0x50 [ 176.266564] [<ffffffff81939199>] system_call_fastpath+0x16/0x1b [ 176.266564] ---[ end trace 387af88219ad6143 ]--- It turns out that spin_unlock_bh(proc_inum_lock) is not safe when put_pid is called with another spinlock held and irqs disabled. For now take the easy path and use spin_lock_irqsave(proc_inum_lock) in proc_free_inum and spin_loc_irq in proc_alloc_inum(proc_inum_lock). Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Bug: 22173056 Backport: commits 0f7aa3c to this one are backport of mnt namespace Signed-off-by: Thierry Strudel <tstrudel@google.com> (cherry picked from commit dfb2ea45be)		2015-07-13 11:21:13 -07:00
..
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs
cachefiles
ceph
cifs	freezer: add unsafe versions of freezable helpers for CIFS	2013-07-12 14:22:55 -07:00
coda
configfs
cramfs
debugfs
devpts
dlm
ecryptfs
efs
exofs
exportfs
ext2
ext3
ext4	ext4: protect group inode free counting with group lock	2013-04-18 16:07:55 -07:00
fat
freevxfs
fscache
fuse	fs: introduce inode operation ->update_time	2015-07-13 11:17:49 -07:00
gfs2
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jbd2
jffs2
jfs
lockd
logfs
minix
ncpfs	fs: introduce inode operation ->update_time	2015-07-13 11:17:49 -07:00
nfs	freezer: add unsafe versions of freezable helpers for NFS	2013-07-12 14:22:55 -07:00
nfs_common
nfsd
nilfs2
nls
notify
ntfs	fs: introduce inode operation ->update_time	2015-07-13 11:17:49 -07:00
ocfs2
omfs
openpromfs
proc	proc: Allow proc_free_inum to be called from any context	2015-07-13 11:21:13 -07:00
pstore
qnx4
qnx6
quota
ramfs
reiserfs
romfs
squashfs
sysfs
sysv
ubifs
udf
ufs
xfs	fs: introduce inode operation ->update_time	2015-07-13 11:17:49 -07:00
yaffs2
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c
block_dev.c
buffer.c	block: fix infinite loop in __getblk_slow	2013-03-15 17:09:41 -07:00
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c
dcache.c	get rid of ->mnt_longterm	2015-07-13 11:17:44 -07:00
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c	epoll: use freezable blocking call	2013-07-12 14:22:57 -07:00
exec.c	seccomp: implement SECCOMP_FILTER_FLAG_TSYNC	2014-10-31 19:46:31 -07:00
fcntl.c
fhandle.c
fifo.c
file.c
file_table.c	brlocks/lglocks: API cleanups	2015-07-13 11:17:41 -07:00
filesystems.c
fs-writeback.c	ext4: fix potential deadlock in ext4_nonda_switch()	2013-03-15 17:09:42 -07:00
fs_struct.c	get rid of ->mnt_longterm	2015-07-13 11:17:44 -07:00
generic_acl.c
inode.c	fs: introduce inode operation ->update_time	2015-07-13 11:17:49 -07:00
internal.h	get rid of ->mnt_longterm	2015-07-13 11:17:44 -07:00
ioctl.c
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mount.h	proc: Usable inode numbers for the namespace file descriptors.	2015-07-13 11:18:01 -07:00
mpage.c
namei.c	VFS: Comment mount following code	2015-07-13 11:17:48 -07:00
namespace.c	proc: Usable inode numbers for the namespace file descriptors.	2015-07-13 11:18:01 -07:00
no-block.c
open.c	vfs: check if f_count is 0 or negative	2014-12-04 13:01:58 -08:00
pipe.c	fs: introduce inode operation ->update_time	2015-07-13 11:17:49 -07:00
pnode.c	VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors	2015-07-13 11:17:46 -07:00
pnode.h	vfs: Only support slave subtrees across different user namespaces	2015-07-13 11:17:56 -07:00
posix_acl.c
proc_namespace.c	get rid of magic in proc_namespace.c	2015-07-13 11:17:45 -07:00
read_write.c
read_write.h
readdir.c
select.c	select: use freezable blocking call	2013-07-12 14:22:58 -07:00
seq_file.c	fs/seq_file: Use vmalloc by default for allocations > PAGE_SIZE	2014-11-18 15:13:24 -08:00
signalfd.c
splice.c	fs: introduce inode operation ->update_time	2015-07-13 11:17:49 -07:00
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
utimes.c
xattr.c
xattr_acl.c