linux/fs
Dmitry Vyukov e41d58185f fault-inject: support systematic fault injection
Add /proc/self/task/<current-tid>/fail-nth file that allows failing
0-th, 1-st, 2-nd and so on calls systematically.
Excerpt from the added documentation:

 "Write to this file of integer N makes N-th call in the current task
  fail (N is 0-based). Read from this file returns a single char 'Y' or
  'N' that says if the fault setup with a previous write to this file
  was injected or not, and disables the fault if it wasn't yet injected.
  Note that this file enables all types of faults (slab, futex, etc).
  This setting takes precedence over all other generic settings like
  probability, interval, times, etc. But per-capability settings (e.g.
  fail_futex/ignore-private) take precedence over it. This feature is
  intended for systematic testing of faults in a single system call. See
  an example below"

Why add a new setting:
1. Existing settings are global rather than per-task.
   So parallel testing is not possible.
2. attr->interval is close but it depends on attr->count
   which is non reset to 0, so interval does not work as expected.
3. Trying to model this with existing settings requires manipulations
   of all of probability, interval, times, space, task-filter and
   unexposed count and per-task make-it-fail files.
4. Existing settings are per-failure-type, and the set of failure
   types is potentially expanding.
5. make-it-fail can't be changed by unprivileged user and aggressive
   stress testing better be done from an unprivileged user.
   Similarly, this would require opening the debugfs files to the
   unprivileged user, as he would need to reopen at least times file
   (not possible to pre-open before dropping privs).

The proposed interface solves all of the above (see the example).

We want to integrate this into syzkaller fuzzer.  A prototype has found
10 bugs in kernel in first day of usage:

  https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance

I've made the current interface work with all types of our sandboxes.
For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to
make /proc entries non-root owned.  So I am fine with the current
version of the code.

[akpm@linux-foundation.org: fix build]
Link: http://lkml.kernel.org/r/20170328130128.101773-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:01 -07:00
..
9p 9p: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
adfs
affs fs/affs: add rename exchange 2017-05-05 15:24:52 -04:00
afs afs: Add metadata xattrs 2017-07-09 14:40:12 -07:00
autofs4 Fix up over-eager 'wait_queue_t' renaming 2017-07-10 11:40:19 -07:00
befs befs: make export work with cold dcache 2017-05-05 11:35:35 +01:00
bfs bfs: fix sanity checks for empty files 2017-07-12 16:26:00 -07:00
btrfs Merge branch 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux 2017-07-10 10:27:48 -07:00
cachefiles sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
ceph ceph: update ceph_dentry_info::lease_session when necessary 2017-07-07 17:25:14 +02:00
cifs cifs: Clean up unused variables in smb2pdu.c 2017-07-09 23:38:00 -05:00
coda fs: implement vfs_iter_write using do_iter_write 2017-06-29 17:49:23 -04:00
configfs configfs: Introduce config_item_get_unless_zero() 2017-06-12 13:20:20 +02:00
cramfs
crypto The first major feature for ext4 this merge window is the largedir 2017-07-09 09:31:22 -07:00
debugfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
devpts
dlm net: Work around lockdep limitation in sockets that use sockets 2017-03-09 18:23:27 -08:00
ecryptfs ecryptfs: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
efivarfs
efs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
exofs mm: drop "wait" parameter from write_one_page() 2017-07-05 18:44:22 -04:00
exportfs Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
ext2 The first major feature for ext4 this merge window is the largedir 2017-07-09 09:31:22 -07:00
ext4 The first major feature for ext4 this merge window is the largedir 2017-07-09 09:31:22 -07:00
f2fs for-f2fs-4.13 2017-07-10 14:29:45 -07:00
fat fat: fix using uninitialized fields of fat_inode/fsinfo_inode 2017-03-09 17:01:10 -08:00
freevxfs
fscache KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload() 2017-03-02 10:09:00 +11:00
fuse Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-05-20 16:12:30 -07:00
gfs2 Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
hfs fs: semove set but not checked AOP_FLAG_UNINTERRUPTIBLE flag 2017-05-08 17:15:14 -07:00
hfsplus fs: semove set but not checked AOP_FLAG_UNINTERRUPTIBLE flag 2017-05-08 17:15:14 -07:00
hostfs
hpfs sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
hugetlbfs mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error 2017-07-10 16:32:30 -07:00
isofs sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
jbd2 Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
jffs2 jffs2: fix spelling mistake: "requestied" -> "requested" 2017-04-19 11:35:55 -07:00
jfs Writeback error handling fixes (pile #1) 2017-07-07 18:39:15 -07:00
kernfs kernfs: Check KERNFS_HAS_RELEASE before calling kernfs_release_file() 2017-03-17 10:25:59 +09:00
lockd Another RDMA update from Chuck Lever, and a bunch of miscellaneous 2017-05-10 13:29:23 -07:00
minix Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
ncpfs mm: per-cgroup memory reclaim stats 2017-07-06 16:24:35 -07:00
nfs Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-07-05 11:26:35 -07:00
nfs_common
nfsd Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-05 14:35:57 -07:00
nilfs2 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 13:08:04 -07:00
nls
notify dentry name snapshots 2017-07-07 20:09:10 -04:00
ntfs ntfs: Use ERR_CAST() to avoid cross-structure cast 2017-05-28 10:11:48 -07:00
ocfs2 ocfs2: constify attribute_group structures 2017-07-06 16:24:30 -07:00
omfs sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
openpromfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
orangefs sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
overlayfs ovl: mark parent impure and restore timestamp on ovl_link_up() 2017-07-04 22:08:15 +02:00
proc fault-inject: support systematic fault injection 2017-07-12 16:26:01 -07:00
pstore pstore: use memdup_user 2017-06-27 17:02:36 -07:00
qnx4
qnx6
quota quota: add get_inode_usage callback to transfer multi-inode charges 2017-06-22 11:46:48 -04:00
ramfs Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
reiserfs sched/wait: Rename wait_queue_t => wait_queue_entry_t 2017-06-20 12:18:27 +02:00
romfs romfs: use different way to generate fsid for BLOCK or MTD 2017-01-24 16:26:14 -08:00
squashfs fs/pstore: fs/squashfs: change usage of LZ4 to work with new LZ4 version 2017-02-24 17:46:57 -08:00
sysfs sysfs: be careful of error returns from ops->show() 2017-04-08 17:33:32 +02:00
sysv mm: drop "wait" parameter from write_one_page() 2017-07-05 18:44:22 -04:00
tracefs fs: constify tree_descr arrays passed to simple_fill_super() 2017-04-26 23:54:06 -04:00
ubifs This pull request contains updates for both UBI and UBIFS: 2017-05-13 10:23:12 -07:00
udf udf: use kmap_atomic for memcpy copying 2017-04-24 16:28:02 +02:00
ufs Writeback error handling fixes (pile #1) 2017-07-07 18:39:15 -07:00
xfs Changes for 4.13: 2017-07-10 10:51:53 -07:00
aio.c fs: add O_DIRECT and aio support for sending down write life time hints 2017-06-27 12:05:36 -06:00
anon_inodes.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
attr.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
bad_inode.c statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00
binfmt_aout.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
binfmt_elf_fdpic.c sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h> 2017-03-02 08:42:39 +01:00
binfmt_elf.c binfmt_elf: safely increment argv pointers 2017-07-10 16:32:36 -07:00
binfmt_em86.c
binfmt_flat.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
binfmt_misc.c fs: constify tree_descr arrays passed to simple_fill_super() 2017-04-26 23:54:06 -04:00
binfmt_script.c
block_dev.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
buffer.c fs/buffer.c: make bh_lru_install() more efficient 2017-07-10 16:32:30 -07:00
char_dev.c chardev: add helper function to register char devs with a struct device 2017-03-21 06:44:32 +01:00
compat_binfmt_elf.c fs/binfmt: Convert obsolete cputime type to nsecs 2017-02-01 09:13:51 +01:00
compat_ioctl.c Merge branch 'work.__copy_in_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:15:02 -07:00
compat.c fs/compat.c: trim unused includes 2017-04-17 12:52:27 -04:00
coredump.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
dax.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
dcache.c fs/dcache.c: fix spin lockup issue on nlru->lock 2017-07-10 16:32:33 -07:00
dcookies.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
direct-io.c fs: add O_DIRECT and aio support for sending down write life time hints 2017-06-27 12:05:36 -06:00
drop_caches.c
eventfd.c There has been a fair amount of activity in the docs tree this time 2017-07-03 21:13:25 -07:00
eventpoll.c kcmp: fs/epoll: wrap kcmp code with CONFIG_CHECKPOINT_RESTORE 2017-07-12 16:26:01 -07:00
exec.c exec: Limit arg stack to at most 75% of _STK_LIM 2017-07-07 20:05:08 -07:00
fcntl.c vfs: fix flock compat thinko 2017-07-07 13:48:18 -07:00
fhandle.c fhandle: move compat syscalls from compat.c 2017-04-17 12:52:26 -04:00
file_table.c fs: new infrastructure for writeback error handling and reporting 2017-07-06 07:02:25 -04:00
file.c fs/file.c: replace alloc_fdmem() with kvmalloc() alternative 2017-07-06 16:24:30 -07:00
filesystems.c fs: warn in case userspace lied about modprobe return 2017-06-29 20:05:43 -04:00
fs_pin.c sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
fs_struct.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> 2017-03-02 08:42:35 +01:00
fs-writeback.c fs: add a blank lines on some kernel-doc comments 2017-05-16 08:44:10 -03:00
inode.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
internal.h Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-09 09:12:53 -07:00
ioctl.c sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependency 2017-03-02 08:42:37 +01:00
iomap.c Changes for 4.13: 2017-07-10 10:51:53 -07:00
Kconfig fs/Kconfig: kill CONFIG_PERCPU_RWSEM some more 2017-07-12 16:26:00 -07:00
Kconfig.binfmt
libfs.c fs: convert __generic_file_fsync to use errseq_t based reporting 2017-07-06 07:02:29 -04:00
locks.c fs/locks: pass kernel struct flock to fcntl_getlk/setlk 2017-05-27 06:07:19 -04:00
Makefile
mbcache.c ext4: xattr inode deduplication 2017-06-22 11:44:55 -04:00
mount.h mnt: In propgate_umount handle visiting mounts in any order 2017-05-23 08:41:16 -05:00
mpage.c There has been a fair amount of activity in the docs tree this time 2017-07-03 21:13:25 -07:00
namei.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
namespace.c mm: update callers to use HASH_ZERO flag 2017-07-06 16:24:33 -07:00
no-block.c
nsfs.c ns: allow ns_entries to have custom symlink content 2017-05-08 17:15:12 -07:00
open.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
pipe.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pnode.c mnt: Make propagate_umount less slow for overlapping mount propagation trees 2017-05-23 08:41:17 -05:00
pnode.h mnt: Tuck mounts under others instead of creating shadow/side mounts. 2017-02-04 00:01:06 +13:00
posix_acl.c sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
proc_namespace.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
read_write.c Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-07 21:48:15 -07:00
readdir.c readdir: move compat syscalls from compat.c 2017-04-17 12:52:24 -04:00
select.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 20:57:13 -07:00
seq_file.c mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
signalfd.c sched/wait: Rename wait_queue_t => wait_queue_entry_t 2017-06-20 12:18:27 +02:00
splice.c fs: implement vfs_iter_write using do_iter_write 2017-06-29 17:49:23 -04:00
stack.c
stat.c ufs: restore maintaining ->i_blocks 2017-06-09 16:28:01 -04:00
statfs.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
super.c bdi: Drop 'parent' argument from bdi_register[_va]() 2017-04-20 12:09:55 -06:00
sync.c fs: remove call_fsync helper function 2017-07-05 18:44:23 -04:00
timerfd.c timerfd: Use get_itimerspec64() and put_itimerspec64() 2017-06-30 04:14:38 -04:00
userfaultfd.c mm/hugetlb: add size parameter to huge_pte_offset() 2017-07-06 16:24:34 -07:00
utimes.c utimes: move compat syscalls from compat.c 2017-04-17 12:52:23 -04:00
xattr.c treewide: use kv[mz]alloc* rather than opencoded variants 2017-05-08 17:15:13 -07:00