Neil Horman 61be228a06 exec: allow do_coredump() to wait for user space pipe readers to complete ... Allow core_pattern pipes to wait for user space to complete One of the things that user space processes like to do is look at metadata for a crashing process in their /proc/<pid> directory. this is racy however, since do_coredump in the kernel doesn't wait for the user space process to complete before it reaps the crashing process. This patch corrects that. Allowing the kernel to wait for the user space process to complete before cleaning up the crashing process. This is a bit tricky to do for a few reasons: 1) The user space process isn't our child, so we can't sys_wait4 on it 2) We need to close the pipe before waiting for the user process to complete, since the user process may rely on an EOF condition I've discussed several solutions with Oleg Nesterov off-list about this, and this is the one we've come up with. We add ourselves as a pipe reader (to prevent premature cleanup of the pipe_inode_info), and remove ourselves as a writer (to provide an EOF condition to the writer in user space), then we iterate until the user space process exits (which we detect by pipe->readers == 1, hence the > 1 check in the loop). When we exit the loop, we restore the proper reader/writer values, then we return and let filp_close in do_coredump clean up the pipe data properly. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Earl Chew <earl_chew@agilent.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2009-09-24 07:21:00 -07:00
..
9p	9p: Add fscache support to 9p	2009-09-23 13:03:46 -05:00
adfs	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
affs	affs: add ->sync_fs	2009-06-11 21:36:14 -04:00
afs	seq_file: constify seq_operations	2009-09-23 07:39:29 -07:00
autofs	trivial: remove unnecessary semicolons	2009-09-21 15:14:58 +02:00
autofs4	autofs4 - fix missed case when changing to use struct path	2009-08-31 17:44:05 -10:00
befs	const: mark remaining super_operations const	2009-09-22 07:17:24 -07:00
bfs	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
btrfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2009-09-22 07:51:45 -07:00
cachefiles	enforce ->sync_fs is only called for rw superblock	2009-06-11 21:36:06 -04:00
cifs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2009-09-22 07:51:45 -07:00
coda	splice: implement default splice_read method	2009-05-11 14:13:10 +02:00
configfs	writeback: add name to backing_dev_info	2009-09-11 09:20:26 +02:00
cramfs	fs/cramfs: return f_fsid for statfs(2)	2009-04-02 19:05:08 -07:00
debugfs	debugfs: use specified mode to possibly mark files read/write only	2009-06-15 21:30:28 -07:00
devpts	Move magic numbers into magic.h	2009-09-23 07:39:28 -07:00
dlm	seq_file: constify seq_operations	2009-09-23 07:39:29 -07:00
ecryptfs	const: mark remaining address_space_operations const	2009-09-22 07:17:24 -07:00
efs	get rid of BKL in fs/efs	2009-06-17 00:36:36 -04:00
exofs	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
exportfs
ext2	ext2: fix format string compile warning (ino_t)	2009-09-23 07:39:58 -07:00
ext3	const: make struct super_block::s_qcop const	2009-09-22 07:17:24 -07:00
ext4	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2009-09-22 07:51:45 -07:00
fat	fat: Opencode sync_page_range_nolock()	2009-09-14 17:08:17 +02:00
freevxfs	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
fscache	FS-Cache: Fixup renamed filenames in comments in internal.h	2009-05-27 10:20:13 -07:00
fuse	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse	2009-09-18 09:23:03 -07:00
gfs2	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
hfs	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
hfsplus	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
hostfs	hostfs: set maximum filesize in superblock for proper LFS support	2009-06-30 18:56:03 -07:00
hpfs	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
hppfs	hppfs: hppfs_read_file() may return -ERROR	2009-04-02 19:04:53 -07:00
hugetlbfs	hugetlbfs: do not call user_shm_lock() for MAP_HUGETLB fix	2009-09-24 07:20:56 -07:00
isofs	isofs: fix Joliet regression	2009-07-10 19:18:59 -07:00
jbd	jbd: Annotate transaction start also for journal_restart()	2009-09-16 17:44:10 +02:00
jbd2	seq_file: constify seq_operations	2009-09-23 07:39:29 -07:00
jffs2	Merge git://git.infradead.org/mtd-2.6	2009-09-23 10:07:49 -07:00
jfs	jffs2/jfs/xfs: switch over to 'check_acl' rather than 'permission()'	2009-09-08 11:09:04 -07:00
lockd	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
minix	V3 minixfs: add missing directory type checking	2009-09-23 07:39:57 -07:00
ncpfs	ncpfs: fix wrong check in __ncp_ioctl()	2009-09-23 07:39:42 -07:00
nfs	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
nfs_common
nfsd	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
nilfs2	const: mark remaining inode_operations as const	2009-09-22 07:17:24 -07:00
nls	NLS: update handling of Unicode	2009-06-15 21:44:43 -07:00
notify	inotify: update the group mask on mark addition	2009-08-28 12:51:14 -04:00
ntfs	ntfs: remove ntfs_file_write	2009-09-23 07:39:29 -07:00
ocfs2	headers: utsname.h redux	2009-09-23 18:13:10 -07:00
omfs	const: mark remaining inode_operations as const	2009-09-22 07:17:24 -07:00
openpromfs
partitions	const: make block_device_operations const	2009-09-22 07:17:25 -07:00
proc	/proc/kcore: update stat.st_size after memory hotplug	2009-09-23 07:39:42 -07:00
qnx4	qnx4: remove write support	2009-09-23 07:39:30 -07:00
quota	const: make struct super_block::s_qcop const	2009-09-22 07:17:24 -07:00
ramfs	ramfs: move RAMFS_MAGIC to include/linux/magic.h	2009-09-23 07:39:42 -07:00
reiserfs	const: make struct super_block::s_qcop const	2009-09-22 07:17:24 -07:00
romfs	const: mark remaining inode_operations as const	2009-09-22 07:17:24 -07:00
smbfs	smbfs: read buffer overflow	2009-09-23 07:39:27 -07:00
squashfs	const: mark remaining super_operations const	2009-09-22 07:17:24 -07:00
sysfs	Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-block	2009-09-11 09:17:05 -07:00
sysv	get rid of BKL in fs/sysv	2009-06-17 00:36:37 -04:00
ubifs	const: mark remaining address_space_operations const	2009-09-22 07:17:24 -07:00
udf	udf: Fix possible corruption when close races with write	2009-09-14 19:13:01 +02:00
ufs	ufs: sector_t cannot be negative	2009-06-18 13:03:46 -07:00
xfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2009-09-22 07:51:45 -07:00
aio.c	aio.c: move EXPORT* macros to line after function	2009-09-23 07:39:29 -07:00
anon_inodes.c	anonfd: split interface into file creation and install	2009-09-23 07:39:29 -07:00
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c	mm: add get_dump_page	2009-09-22 07:17:40 -07:00
binfmt_elf.c	mm: add get_dump_page	2009-09-22 07:17:40 -07:00
binfmt_em86.c
binfmt_flat.c	flat: fix uninitialized ptr with shared libs	2009-08-07 10:39:57 -07:00
binfmt_misc.c
binfmt_script.c
binfmt_som.c	Don't crap into descriptor table in binfmt_som	2009-03-31 23:00:28 -04:00
bio-integrity.c	block: Create bip slabs with embedded integrity vectors	2009-07-01 10:56:25 +02:00
bio.c	block: fix sg SG_DXFER_TO_FROM_DEV regression	2009-07-10 20:31:53 +02:00
block_dev.c	const: make block_device_operations const	2009-09-22 07:17:25 -07:00
buffer.c	fs/buffer.c: clean up EXPORT* macros	2009-09-23 07:39:29 -07:00
char_dev.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6	2009-09-11 09:19:35 -07:00
compat_binfmt_elf.c
compat_ioctl.c	compat_ioctl: hook up compat handler for FIEMAP ioctl	2009-08-07 10:39:56 -07:00
compat.c	fix compat_sys_utimensat()	2009-09-23 07:39:30 -07:00
dcache.c	sched: Pull up the might_sleep() check into cond_resched()	2009-07-18 15:51:44 +02:00
dcookies.c
direct-io.c	block: Do away with the notion of hardsect_size	2009-05-22 23:22:54 +02:00
drop_caches.c	mm: remove __invalidate_mapping_pages variant	2009-06-16 19:47:43 -07:00
eventfd.c	anonfd: split interface into file creation and install	2009-09-23 07:39:29 -07:00
eventpoll.c	epoll: fix nested calls support	2009-06-18 13:03:41 -07:00
exec.c	exec: allow do_coredump() to wait for user space pipe readers to complete	2009-09-24 07:21:00 -07:00
fcntl.c	headers: smp_lock.h redux	2009-07-12 12:22:34 -07:00
fifo.c
file_table.c	fs: move mark_files_ro into file_table.c	2009-06-11 21:36:02 -04:00
file.c
filesystems.c	fs: Mark get_filesystem_list() as __init function.	2009-04-20 23:02:52 -04:00
fs_struct.c	Get rid of indirect include of fs_struct.h	2009-03-31 23:00:27 -04:00
fs-writeback.c	writeback: fix possible bdi writeback refcounting problem	2009-09-16 15:18:53 +02:00
generic_acl.c	New helper - current_umask()	2009-03-31 23:00:26 -04:00
inode.c	fs: turn iprune_mutex into rwsem	2009-09-23 07:39:29 -07:00
internal.h	Trim a bit of crap from fs.h	2009-06-11 21:36:07 -04:00
ioctl.c	fs: Add new pre-allocation ioctls to vfs for compatibility with legacy xfs ioctls	2009-06-24 08:15:27 -04:00
ioprio.c
Kconfig	tmpfs: depend on shmem	2009-09-22 07:17:41 -07:00
Kconfig.binfmt
libfs.c	vfs: make get_sb_pseudo set s_maxbytes to value that can be cast to signed	2009-08-18 16:31:12 -07:00
locks.c	const: make lock_manager_operations const	2009-09-22 07:17:25 -07:00
Makefile	nilfs2: update makefile and Kconfig	2009-04-07 08:31:16 -07:00
mbcache.c
mpage.c	ext4: Properly initialize the buffer_head state	2009-05-13 15:13:42 -04:00
namei.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6	2009-09-11 08:55:49 -07:00
namespace.c	vfs: mnt_want_write_file(): fix special file handling	2009-08-07 10:39:56 -07:00
nfsctl.c
no-block.c
open.c	fs: change sys_truncate length parameter type	2009-09-23 09:21:05 -07:00
pipe.c	lockdep: Fix lockdep annotation for pipe_double_lock()	2009-07-22 21:14:14 +02:00
pnode.c
pnode.h
posix_acl.c
read_write.c	splice: implement default splice_read method	2009-05-11 14:13:10 +02:00
read_write.h
readdir.c
select.c	poll/select: avoid arithmetic overflow in __estimate_accuracy()	2009-09-23 07:39:27 -07:00
seq_file.c	seq_file: add function to write binary data	2009-06-18 13:03:57 -07:00
signalfd.c
splice.c	Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block	2009-09-14 17:55:15 -07:00
stack.c
stat.c	kill vfs_stat_fd / vfs_lstat_fd	2009-04-20 23:02:52 -04:00
super.c	const: mark remaining super_operations const	2009-09-22 07:17:24 -07:00
sync.c	fs/buffer.c: clean up EXPORT* macros	2009-09-23 07:39:29 -07:00
timerfd.c
utimes.c
xattr_acl.c
xattr.c	VFS: Factor out part of vfs_setxattr so it can be called from the SELinux hook for inode_setsecctx.	2009-09-10 10:11:22 +10:00