If compression feature is on, in scenario of no enough free memory,
page refault ratio is higher than before, the root cause is:
- {,de}compression flow needs to allocate intermediate pages to store
compressed data in cluster, so during their allocation, vm may reclaim
mmaped pages.
- if above reclaimed pages belong to compressed cluster, during its
refault, it may cause more intermediate pages allocation, result in
reclaiming more mmaped pages.

So this patch introduces a mempool for intermediate page allocation,
in order to avoid high refault ratio, by default, number of
preallocated page in pool is 512, user can change the number by
assigning 'num_compress_pages' parameter during module initialization.

Ma Feng found warnings in the original patch and fixed like below.

Fix the following sparse warning:
fs/f2fs/compress.c:501:5: warning: symbol 'num_compress_pages' was not declared.
 Should it be static?
fs/f2fs/compress.c:530:6: warning: symbol 'f2fs_compress_free_page' was not
declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Ma Feng <mafeng.ma@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

to support bmap() on compressed inode: if queried block locates in
non-compressed cluster, return its physical block address.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Map normal/compressed cluster of compressed inode correctly, and give
the right fiemap flag FIEMAP_EXTENT_ENCODED on mapped compressed extent.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Supports to truncate compressed/normal cluster partially on compressed
inode.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

due to f2fs_post_read_required() has did that.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Remove the pointless string length checks.  Just use strcmp().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch corrects the SPDX License Identifier style in
header files related to F2FS File System support.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs_quota_sync() uses f2fs_lock_op() before flushing dirty pages, but
f2fs_write_data_page() returns EAGAIN.
Likewise dentry blocks, we can just bypass getting the lock, since quota
blocks are also maintained by checkpoint.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Adds to support accounting read IOs from userspace/kernel.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When a discard_cmd needs to be split due to dpolicy->max_requests, then
for the remaining length it will be either merged into another cmd or a
new discard_cmd will be created. In this case, there is double
accounting of dcc->undiscard_blks for the remaining len, due to which
it shows incorrect value in stats.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In f2fs_ra_meta_pages(), if f2fs_submit_page_bio() failed, we need to
unlock page, fix it.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In case a discard_cmd is split into several bios, the dc->error
must not be overwritten once an error is reported by a bio. Also,
move it under dc->lock.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

F2FS already has a default timeout of 5 secs for discards that
can be issued during umount, but it can take more than the 5 sec
timeout if the underlying UFS device queue is already full and there
are no more available free tags to be used. Fix this by submitting a
small batch of discard requests so that it won't cause the device
queue to be full at any time and thus doesn't incur its wait time
in the umount context.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Added a tracepoint to see iostat of f2fs. Default period of that
is 3 second. This tracepoint can be used to be monitoring
I/O statistics periodically.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch introduces a way to attach REQ_META/FUA explicitly
to all the data writes given temperature.

-> attach REQ_FUA to Hot Data writes

-> attach REQ_FUA to Hot|Warm Data writes

-> attach REQ_FUA to Hot|Warm|Cold Data writes

-> attach REQ_FUA to Hot|Warm|Cold Data writes as well as
          REQ_META to Hot Data writes
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Merge more updates from Andrew Morton:

 - a lot more of MM, quite a bit more yet to come: (memcg, pagemap,
   vmalloc, pagealloc, migration, thp, ksm, madvise, virtio,
   userfaultfd, memory-hotplug, shmem, rmap, zswap, zsmalloc, cleanups)

 - various other subsystems (procfs, misc, MAINTAINERS, bitops, lib,
   checkpatch, epoll, binfmt, kallsyms, reiserfs, kmod, gcov, kconfig,
   ubsan, fault-injection, ipc)

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (158 commits)
  ipc/shm.c: make compat_ksys_shmctl() static
  ipc/mqueue.c: fix a brace coding style issue
  lib/Kconfig.debug: fix a typo "capabilitiy" -> "capability"
  ubsan: include bug type in report header
  kasan: unset panic_on_warn before calling panic()
  ubsan: check panic_on_warn
  drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks
  ubsan: split "bounds" checker from other options
  ubsan: add trap instrumentation option
  init/Kconfig: clean up ANON_INODES and old IO schedulers options
  kernel/gcov/fs.c: replace zero-length array with flexible-array member
  gcov: gcc_3_4: replace zero-length array with flexible-array member
  gcov: gcc_4_7: replace zero-length array with flexible-array member
  kernel/kmod.c: fix a typo "assuems" -> "assumes"
  reiserfs: clean up several indentation issues
  kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()
  samples/hw_breakpoint: drop use of kallsyms_lookup_name()
  samples/hw_breakpoint: drop HW_BREAKPOINT_R when reporting writes
  fs/binfmt_elf.c: don't free interpreter's ELF pheaders on common path
  fs/binfmt_elf.c: allocate less for static executable
  ...

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - Fix a page leak in nfs_destroy_unlinked_subrequests()

   - Fix use-after-free issues in nfs_pageio_add_request()

   - Fix new mount code constant_table array definitions

   - finish_automount() requires us to hold 2 refs to the mount record

  Features:
   - Improve the accuracy of telldir/seekdir by using 64-bit cookies
     when possible.

   - Allow one RDMA active connection and several zombie connections to
     prevent blocking if the remote server is unresponsive.

   - Limit the size of the NFS access cache by default

   - Reduce the number of references to credentials that are taken by
     NFS

   - pNFS files and flexfiles drivers now support per-layout segment
     COMMIT lists.

   - Enable partial-file layout segments in the pNFS/flexfiles driver.

   - Add support for CB_RECALL_ANY to the pNFS flexfiles layout type

   - pNFS/flexfiles Report NFS4ERR_DELAY and NFS4ERR_GRACE errors from
     the DS using the layouterror mechanism.

  Bugfixes and cleanups:
   - SUNRPC: Fix krb5p regressions

   - Don't specify NFS version in "UDP not supported" error

   - nfsroot: set tcp as the default transport protocol

   - pnfs: Return valid stateids in nfs_layout_find_inode_by_stateid()

   - alloc_nfs_open_context() must use the file cred when available

   - Fix locking when dereferencing the delegation cred

   - Fix memory leaks in O_DIRECT when nfs_get_lock_context() fails

   - Various clean ups of the NFS O_DIRECT commit code

   - Clean up RDMA connect/disconnect

   - Replace zero-length arrays with C99-style flexible arrays"

* tag 'nfs-for-5.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (86 commits)
  NFS: Clean up process of marking inode stale.
  SUNRPC: Don't start a timer on an already queued rpc task
  NFS/pnfs: Reference the layout cred in pnfs_prepare_layoutreturn()
  NFS/pnfs: Fix dereference of layout cred in pnfs_layoutcommit_inode()
  NFS: Beware when dereferencing the delegation cred
  NFS: Add a module parameter to set nfs_mountpoint_expiry_timeout
  NFS: finish_automount() requires us to hold 2 refs to the mount record
  NFS: Fix a few constant_table array definitions
  NFS: Try to join page groups before an O_DIRECT retransmission
  NFS: Refactor nfs_lock_and_join_requests()
  NFS: Reverse the submission order of requests in __nfs_pageio_add_request()
  NFS: Clean up nfs_lock_and_join_requests()
  NFS: Remove the redundant function nfs_pgio_has_mirroring()
  NFS: Fix memory leaks in nfs_pageio_stop_mirroring()
  NFS: Fix a request reference leak in nfs_direct_write_clear_reqs()
  NFS: Fix use-after-free issues in nfs_pageio_add_request()
  NFS: Fix races nfs_page_group_destroy() vs nfs_destroy_unlinked_subrequests()
  NFS: Fix a page leak in nfs_destroy_unlinked_subrequests()
  NFS: Remove unused FLUSH_SYNC support in nfs_initiate_pgio()
  pNFS/flexfiles: Specify the layout segment range in LAYOUTGET
  ...

Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've mainly focused on fixing bugs and addressing
  issues in recently introduced compression support.

  Enhancement:
   - add zstd support, and set LZ4 by default
   - add ioctl() to show # of compressed blocks
   - show mount time in debugfs
   - replace rwsem with spinlock
   - avoid lock contention in DIO reads

  Some major bug fixes wrt compression:
   - compressed block count
   - memory access and leak
   - remove obsolete fields
   - flag controls

  Other bug fixes and clean ups:
   - fix overflow when handling .flags in inode_info
   - fix SPO issue during resize FS flow
   - fix compression with fsverity enabled
   - potential deadlock when writing compressed pages
   - show missing mount options"

* tag 'f2fs-for-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (66 commits)
  f2fs: keep inline_data when compression conversion
  f2fs: fix to disable compression on directory
  f2fs: add missing CONFIG_F2FS_FS_COMPRESSION
  f2fs: switch discard_policy.timeout to bool type
  f2fs: fix to verify tpage before releasing in f2fs_free_dic()
  f2fs: show compression in statx
  f2fs: clean up dic->tpages assignment
  f2fs: compress: support zstd compress algorithm
  f2fs: compress: add .{init,destroy}_decompress_ctx callback
  f2fs: compress: fix to call missing destroy_compress_ctx()
  f2fs: change default compression algorithm
  f2fs: clean up {cic,dic}.ref handling
  f2fs: fix to use f2fs_readpage_limit() in f2fs_read_multi_pages()
  f2fs: xattr.h: Make stub helpers inline
  f2fs: fix to avoid double unlock
  f2fs: fix potential .flags overflow on 32bit architecture
  f2fs: fix NULL pointer dereference in f2fs_verity_work()
  f2fs: fix to clear PG_error if fsverity failed
  f2fs: don't call fscrypt_get_encryption_info() explicitly in f2fs_tmpfile()
  f2fs: don't trigger data flush in foreground operation
  ...

Pull UBI and UBIFS updates from Richard Weinberger:

 - Fix for memory leaks around UBIFS orphan handling

 - Fix for memory leaks around UBI fastmap

 - Remove zero-length array from ubi-media.h

 - Fix for TNC lookup in UBIFS orphan code

* tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubi: ubi-media.h: Replace zero-length array with flexible-array member
  ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len
  ubi: fastmap: Only produce the initial anchor PEB when fastmap is used
  ubi: fastmap: Free unused fastmap anchor peb during detach
  ubifs: ubifs_add_orphan: Fix a memory leak bug
  ubifs: ubifs_jnl_write_inode: Fix a memory leak bug
  ubifs: Fix ubifs_tnc_lookup() usage in do_kill_orphans()

Pull UML updates from Richard Weinberger:

 - New mode for time travel, external via virtio

 - Fixes for ubd to make sure no requests can get lost

 - Fixes for vector networking

 - Allow CONFIG_STATIC_LINK only when possible

 - Minor cleanups and fixes

* tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Remove some unnecessary NULL checks in vector_user.c
  um: vector: Avoid NULL ptr deference if transport is unset
  um: Make CONFIG_STATIC_LINK actually static
  um: Implement cpu_relax() as ndelay(1) for time-travel
  um: Implement ndelay/udelay in time-travel mode
  um: Implement time-travel=ext
  um: virtio: Implement VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS
  um: time-travel: Rewrite as an event scheduler
  um: Move timer-internal.h to non-shared
  hostfs: Use kasprintf() instead of fixed buffer formatting
  um: falloc.h needs to be directly included for older libc
  um: ubd: Retry buffer read on any kind of error
  um: ubd: Prevent buffer overrun on command completion
  um: Fix overlapping ELF segments when statically linked
  um: Delete never executed timer
  um: Don't overwrite ethtool driver version
  um: Fix len of file in create_pid_file
  um: Don't use console_drivers directly
  um: Cleanup CONFIG_IOSCHED_CFQ

Pull OpenRISC updates from Stafford Horne:
 "A few cleanups all over the place, things of note:

   - Enable the clone3 syscall

   - Remove CONFIG_CROSS_COMPILE from Krzysztof Kozlowski

   - Update to use mmgrab from Julia Lawall"

* tag 'for-linus' of git://github.com/openrisc/linux:
  openrisc: Remove obsolete show_trace_task function
  openrisc: Cleanup copy_thread_tls docs and comments
  openrisc: Enable the clone3 syscall
  openrisc: Convert copy_thread to copy_thread_tls
  openrisc: use mmgrab
  openrisc: configs: Cleanup CONFIG_CROSS_COMPILE

Pull parisc updates from Helge Deller:
 "Some cleanups in arch_rw locking functions, improved interrupt
  handling in arch spinlocks, coversions to request_irq() and syscall
  table generation cleanups"

* 'parisc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: remove nargs from __SYSCALL
  parisc: Refactor alternative code to accept multiple conditions
  parisc: Rework arch_rw locking functions
  parisc: Improve interrupt handling in arch_spin_lock_flags()
  parisc: Replace setup_irq() by request_irq()

Pull sparc update from David Miller:
 "A per-device DMA ops conversion for sparc32 by Chrstioph Hellwig"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc32: use per-device dma_ops

Pull IDE update from David Miller:
 "As usual, very quiet in this subsystem.

  Just a list_for_each_entry_safe() conversion"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide:
  drivers/ide: Fix build regression.
  drivers/ide: convert to list_for_each_entry_safe()

Pull networking fixes from David Miller:

 1) Slave bond and team devices should not be assigned ipv6 link local
    addresses, from Jarod Wilson.

 2) Fix clock sink config on some at803x PHY devices, from Oleksij
    Rempel.

 3) Uninitialized stack space transmitted in slcan frames, fix from
    Richard Palethorpe.

 4) Guard HW VLAN ops properly in stmmac driver, from Jose Abreu.

 5) "=" --> "|=" fix in aquantia driver, from Colin Ian King.

 6) Fix TCP fallback in mptcp, from Florian Westphal. (accessing a plain
    tcp_sk as if it were an mptcp socket).

 7) Fix cavium driver in some configurations wrt. PTP, from Yue Haibing.

 8) Make ipv6 and ipv4 consistent in the lower bound allowed for
    neighbour entry retrans_time, from Hangbin Liu.

 9) Don't use private workqueue in pegasus usb driver, from Petko
    Manolov.

10) Fix integer overflow in mlxsw, from Colin Ian King.

11) Missing refcnt init in cls_tcindex, from Cong Wang.

12) One too many loop iterations when processing cmpri entries in ipv6
    rpl code, from Alexander Aring.

13) Disable SG and TSO by default in r8169, from Heiner Kallweit.

14) NULL deref in macsec, from Davide Caratti.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (42 commits)
  macsec: fix NULL dereference in macsec_upd_offload()
  skbuff.h: Improve the checksum related comments
  net: dsa: bcm_sf2: Ensure correct sub-node is parsed
  qed: remove redundant assignment to variable 'rc'
  wimax: remove some redundant assignments to variable result
  mlxsw: spectrum_flower: Do not stop at FLOW_ACTION_VLAN_MANGLE
  mlxsw: spectrum_flower: Do not stop at FLOW_ACTION_PRIORITY
  r8169: change back SG and TSO to be disabled by default
  net: dsa: bcm_sf2: Do not register slave MDIO bus with OF
  ipv6: rpl: fix loop iteration
  tun: Don't put_page() for all negative return values from XDP program
  net: dsa: mt7530: fix null pointer dereferencing in port5 setup
  mptcp: add some missing pr_fmt defines
  net: phy: micrel: kszphy_resume(): add delay after genphy_resume() before accessing PHY registers
  net_sched: fix a missing refcnt in tcindex_init()
  net: stmmac: dwmac1000: fix out-of-bounds mac address reg setting
  mlxsw: spectrum_trap: fix unintention integer overflow on left shift
  pegasus: Remove pegasus' own workqueue
  neigh: support smaller retrans_time settting
  net: openvswitch: use hlist_for_each_entry_rcu instead of hlist_for_each_entry
  ...

Pull pcmcia updates from Dominik Brodowski:
 "A few PCMCIA odd fixes: removing a few spaces and useless casts,
  replacing snprintf() with scnprintf(), and replacing zero-length
  arrays with a flexible-array member"

* 'pcmcia-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux:
  pcmcia: remove some unused space characters
  pcmcia: soc_common.h: Replace zero-length array with flexible-array member
  pcmcia: cs_internal.h: Replace zero-length array with flexible-array member
  pcmcia: Use scnprintf() for avoiding potential buffer overflow
  pcmcia: omap: remove useless cast for driver.name

Fix the following sparse warning:

ipc/shm.c:1335:6: warning: symbol 'compat_ksys_shmctl' was not declared.
Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200403063933.24785-1-yanaijie@huawei.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: somala swaraj <somalaswaraj@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200301135530.18340-1-somalaswaraj@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s/capabilitiy/capability
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1585818594-27373-1-git-send-email-hqjagain@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When syzbot tries to figure out how to deduplicate bug reports, it prefers
seeing a hint about a specific bug type (we can do better than just
"UBSAN").  This lifts the handler reason into the UBSAN report line that
includes the file path that tripped a check.  Unfortunately, UBSAN does
not provide function names.
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Link: http://lkml.kernel.org/r/20200227193516.32566-7-keescook@chromium.org
Link: https://lore.kernel.org/lkml/CACT4Y+bsLJ-wFx_TaXqax3JByUOWB3uk787LsyMVcfW6JzzGvg@mail.gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As done in the full WARN() handler, panic_on_warn needs to be cleared
before calling panic() to avoid recursive panics.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Link: http://lkml.kernel.org/r/20200227193516.32566-6-keescook@chromium.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Syzkaller expects kernel warnings to panic when the panic_on_warn sysctl
is set.  More work is needed here to have UBSan reuse the WARN
infrastructure, but for now, just check the flag manually.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Link: https://lore.kernel.org/lkml/CACT4Y+bsLJ-wFx_TaXqax3JByUOWB3uk787LsyMVcfW6JzzGvg@mail.gmail.com
Link: http://lkml.kernel.org/r/20200227193516.32566-5-keescook@chromium.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Adds LKDTM tests for arithmetic overflow (both signed and unsigned), as
well as array bounds checking.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Link: http://lkml.kernel.org/r/20200227193516.32566-4-keescook@chromium.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In order to do kernel builds with the bounds checker individually
available, introduce CONFIG_UBSAN_BOUNDS, with the remaining options under
CONFIG_UBSAN_MISC.

For example, using this, we can start to expand the coverage syzkaller is
providing.  Right now, all of UBSan is disabled for syzbot builds because
taken as a whole, it is too noisy.  This will let us focus on one feature
at a time.

For the bounds checker specifically, this provides a mechanism to
eliminate an entire class of array overflows with close to zero
performance overhead (I cannot measure a difference).  In my (mostly)
defconfig, enabling bounds checking adds ~4200 checks to the kernel.
Performance changes are in the noise, likely due to the branch predictors
optimizing for the non-fail path.

Some notes on the bounds checker:

- it does not instrument {mem,str}*()-family functions, it only
  instruments direct indexed accesses (e.g. "foo[i]"). Dealing with
  the {mem,str}*()-family functions is a work-in-progress around
  CONFIG_FORTIFY_SOURCE[1].

- it ignores flexible array members, including the very old single
  byte (e.g. "int foo[1];") declarations. (Note that GCC's
  implementation appears to ignore _all_ trailing arrays, but Clang only
  ignores empty, 0, and 1 byte arrays[2].)

[1] https://github.com/KSPP/linux/issues/6
[2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92589Suggested-by: Elena Petrova <lenaptr@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Link: http://lkml.kernel.org/r/20200227193516.32566-3-keescook@chromium.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "ubsan: Split out bounds checker", v5.

This splits out the bounds checker so it can be individually used.  This
is enabled in Android and hopefully for syzbot.  Includes LKDTM tests for
behavioral corner-cases (beyond just the bounds checker), and adjusts
ubsan and kasan slightly for correct panic handling.

This patch (of 6):

The Undefined Behavior Sanitizer can operate in two modes: warning
reporting mode via lib/ubsan.c handler calls, or trap mode, which uses
__builtin_trap() as the handler.  Using lib/ubsan.c means the kernel image
is about 5% larger (due to all the debugging text and reporting structures
to capture details about the warning conditions).  Using the trap mode,
the image size changes are much smaller, though at the loss of the
"warning only" mode.

In order to give greater flexibility to system builders that want minimal
changes to image size and are prepared to deal with kernel code being
aborted and potentially destabilizing the system, this introduces
CONFIG_UBSAN_TRAP.  The resulting image sizes comparison:

   text    data     bss       dec       hex     filename
19533663   6183037  18554956  44271656  2a38828 vmlinux.stock
19991849   7618513  18874448  46484810  2c54d4a vmlinux.ubsan
19712181   6284181  18366540  44362902  2a4ec96 vmlinux.ubsan-trap

CONFIG_UBSAN=y:      image +4.8% (text +2.3%, data +18.9%)
CONFIG_UBSAN_TRAP=y: image +0.2% (text +0.9%, data +1.6%)

Additionally adjusts the CONFIG_UBSAN Kconfig help for clarity and removes
the mention of non-existing boot param "ubsan_handle".
Suggested-by: Elena Petrova <lenaptr@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Link: http://lkml.kernel.org/r/20200227193516.32566-2-keescook@chromium.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

CONFIG_ANON_INODES is gone since commit 5dd50aae ("Make anon_inodes
unconditional").

CONFIG_CFQ_GROUP_IOSCHED was replaced with CONFIG_BFQ_GROUP_IOSCHED in
commit f382fb0b ("block: remove legacy IO schedulers").
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: http://lkml.kernel.org/r/20200130192419.3026-1-krzk@kernel.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The current codebase makes use of the zero-length array language extension
to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by this
change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied.  As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Link: http://lkml.kernel.org/r/20200302224851.GA26467@embeddedorSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The current codebase makes use of the zero-length array language extension
to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by this
change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied.  As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Link: http://lkml.kernel.org/r/20200302224501.GA14175@embeddedorSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The current codebase makes use of the zero-length array language extension
to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by this
change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied.  As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Link: http://lkml.kernel.org/r/20200213152241.GA877@embeddedorSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is a typo in comment.  Fix it.  s/assuems/assumes/
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: http://lkml.kernel.org/r/1585891029-6450-1-git-send-email-hqjagain@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>