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Theodore Ts'o and others added 30 commits September 6, 2016 02:43
This takes code from fs/mpage.c and optimizes it for ext4.  Its
primary reason is to allow us to more easily add encryption to ext4's
read path in an efficient manner.

Change-Id: I1fd07e78fbbff50fd4028bbffbee73dbaec546a1
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I3cc7669ce5c2902bacf9ec365b1ba7049be781f0
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I784c5f57f031981e5d28796921f5e587d4f72422
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Required for future encryption xattr changes.

Change-Id: Ieaff30ae755d76f562c6c4b110bc0c1c59ea4dfd
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I6325cdbfb9666cca194b462878c157bd0449302e
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: Iaabf029d28db2bd27e492e4e1bf7adc034b066e8
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
On encrypt, we will re-assign the buffer_heads to point to a bounce
page rather than the control_page (which is the original page to write
that contains the plaintext). The block I/O occurs against the bounce
page.  On write completion, we re-assign the buffer_heads to the
original plaintext page.

On decrypt, we will attach a read completion callback to the bio
struct. This read completion will decrypt the read contents in-place
prior to setting the page up-to-date.

The current encryption mode, AES-256-XTS, lacks cryptographic
integrity. AES-256-GCM is in-plan, but we will need to devise a
mechanism for handling the integrity data.

Change-Id: Icf3814a88aed38f24bf615663f9921f5c390fb32
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I4914284877331994b0d1f701bcbbcf820116e8ee
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Enforce the following inheritance policy:

1) An unencrypted directory may contain encrypted or unencrypted files
or directories.

2) All files or directories in a directory must be protected using the
same key as their containing directory.

As a result, assuming the following setup:

mke2fs -t ext4 -Fq -O encrypt /dev/vdc
mount -t ext4 /dev/vdc /vdc
mkdir /vdc/a /vdc/b /vdc/c
echo foo | e4crypt add_key /vdc/a
echo bar | e4crypt add_key /vdc/b
for i in a b c ; do cp /etc/motd /vdc/$i/motd-$i ; done

Then we will see the following results:

cd /vdc
mv a b			# will fail; /vdc/a and /vdc/b have different keys
mv b/motd-b a		# will fail, see above
ln a/motd-a b		# will fail, see above
mv c a	    		# will fail; all inodes in an encrypted directory
   	  		#	must be encrypted
ln c/motd-c b		# will fail, see above
mv a/motd-a c		# will succeed
mv c/motd-a a		# will succeed

Change-Id: I0eb702a4e5c426dfd38863ada7bdec3741e1ee8b
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: Ic06753bdc015fc12b4f5620dfc15955765b1f117
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Pulls block_write_begin() into fs/ext4/inode.c because it might need
to do a low-level read of the existing data, in which case we need to
decrypt it.

Change-Id: Ib2067d50cb80e9017ccf7016b2e72683ebd4c74a
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I69043c9b36be0f8db1e80dfba54382d5328d9d4b
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I52b2ad72b4599a720f6f7db27acb6a39fa2265c9
Signed-off-by: Uday Savagaonkar <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
…ames

For encrypted directories, we need to pass in a separate parameter for
the decrypted filename, since the directory entry contains the
encrypted filename.

Change-Id: Ie28cbb198c41daa743a3a18ab25ff2e4d016c275
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I7c222d4b7ba8be500f228d24598ec4f402baffd3
Signed-off-by: Uday Savagaonkar <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Modifies dx_show_leaf and dx_probe to support fname encryption.
Filename encryption not yet enabled.

Change-Id: Ib95c5819180bc67f8904f677224e1b7e02019aaf
Signed-off-by: Uday Savagaonkar <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Modifies htree_dirblock_to_tree, dx_make_map, ext4_match search_dir,
and ext4_find_dest_de to support fname crypto.  Filename encryption
feature is not yet enabled at this patch.

Change-Id: Iace4aac9931d7ddeafe494c8d5ab09c6d356f0b1
Signed-off-by: Uday Savagaonkar <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I25e65769ac98e5c0aa0d1a8b9ad765fcd300e8eb
Signed-off-by: Uday Savagaonkar <[email protected]>
Signed-off-by: Ildar Muslukhov <[email protected]>
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: Ia3a2f08b64023cdaaa8bed57a8ae19913ea5729a
Signed-off-by: Uday Savagaonkar <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Also add the test dummy encryption mode flag so we can more easily
test the encryption patches using xfstests.

Change-Id: I30b08de00e5fbf2efcc13d2e8ffb0f625a21e4ce
Signed-off-by: Michael Halcrow <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Avoid using SHA-1 when calculating the user-visible filename when the
encryption key is available, and avoid decrypting lots of filenames
when searching for a directory entry in a directory block.

Change-Id: Iaa566fdbb274e6def7c70282b737a07ad5c2c50c
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
This obscures the length of the filenames, to decrease the amount of
information leakage.  By default, we pad the filenames to the next 4
byte boundaries.  This costs nothing, since the directory entries are
aligned to 4 byte boundaries anyway.  Filenames can also be padded to
8, 16, or 32 bytes, which will consume more directory space.

Change-Id: I20625aa7b79bbe2cd511933655aac4755fd5273d
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
This patch adds a tristate EXT4_ENCRYPTION to do the selections
for EXT4_FS_ENCRYPTION because selecting from a bool causes all
the selected options to be built-in, even if EXT4 itself is a
module.

Change-Id: I431434e48f96728efa64f324974825848f34718a
Signed-off-by: Herbert Xu <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Encrypt the filename as soon it is passed in by the user.  This avoids
our needing to encrypt the filename 2 or 3 times while in the process
of creating a filename.

Similarly, when looking up a directory entry, encrypt the filename
early, or if the encryption key is not available, base-64 decode the
file syystem so that the hash value and the last 16 bytes of the
encrypted filename is available in the new struct ext4_filename data
structure.

Change-Id: I6b77f282b78d53431a1bf5659cd079a52961940f
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Change-Id: I333d2e3989411cb47e7b1e10250f00e973c08c6c
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Use struct ext4_encryption_key only for the master key passed via the
kernel keyring.

For internal kernel space users, we now use struct ext4_crypt_info.
This will allow us to put information from the policy structure so we
can cache it and avoid needing to constantly looking up the extended
attribute.  We will do this in a spearate patch.  This patch is mostly
mechnical to make it easier for patch review.

Change-Id: I51c01abecb64308ee1039f318c24e42b6ad06f5b
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
This is a pretty massive patch which does a number of different things:

1) The per-inode encryption information is now stored in an allocated
   data structure, ext4_crypt_info, instead of directly in the node.
   This reduces the size usage of an in-memory inode when it is not
   using encryption.

2) We drop the ext4_fname_crypto_ctx entirely, and use the per-inode
   encryption structure instead.  This remove an unnecessary memory
   allocation and free for the fname_crypto_ctx as well as allowing us
   to reuse the ctfm in a directory for multiple lookups and file
   creations.

3) We also cache the inode's policy information in the ext4_crypt_info
   structure so we don't have to continually read it out of the
   extended attributes.

4) We now keep the keyring key in the inode's encryption structure
   instead of releasing it after we are done using it to derive the
   per-inode key.  This allows us to test to see if the key has been
   revoked; if it has, we prevent the use of the derived key and free
   it.

5) When an inode is released (or when the derived key is freed), we
   will use memset_explicit() to zero out the derived key, so it's not
   left hanging around in memory.  This implies that when a user logs
   out, it is important to first revoke the key, and then unlink it,
   and then finally, to use "echo 3 > /proc/sys/vm/drop_caches" to
   release any decrypted pages and dcache entries from the system
   caches.

6) All this, and we also shrink the number of lines of code by around
   100.  :-)

Change-Id: Ide8129a31ac04cb4905a76600e66bf9f7ef2d2bd
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
The superblock fields s_file_encryption_mode and s_dir_encryption_mode
are vestigal, so remove them as a cleanup.  While we're at it, allow
file systems with both encryption and inline_data enabled at the same
time to work correctly.  We can't have encrypted inodes with inline
data, but there's no reason to prohibit unencrypted inodes from using
the inline data feature.

Change-Id: I3875d3db9790cec7b3a756a997f8fb0d86c9d623
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Use slab caches the ext4_crypto_ctx and ext4_crypt_info structures for
slighly better memory efficiency and debuggability.

Change-Id: Ia820c8daae53fefd185d5f0d757d4279c78676d8
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
The ci_mode field was superfluous, and getting rid of it gets rid of
an unused hole in the structure.

Change-Id: I317165e6219c164af29047a314a3187e94f20f2e
Signed-off-by: Theodore Ts'o <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Martinusbe referenced this pull request in MR-op3/kernel_oneplus_msm8996 Sep 19, 2016
we found this issue but still exit in lastest kernel. Simply
keep ion_handle_create under mutex_lock to avoid this race.

WARNING: CPU: 2 PID: 2648 at drivers/staging/android/ion/ion.c:512 ion_handle_add+0xb4/0xc0()
ion_handle_add: buffer already found.
Modules linked in: iwlmvm iwlwifi mac80211 cfg80211 compat
CPU: 2 PID: 2648 Comm: TimedEventQueue Tainted: G        W    3.14.0 GZR-Kernels#7
 00000000 00000000 9a3efd2c 80faf273 9a3efd6c 9a3efd5c 80935dc9 811d7fd3
 9a3efd88 00000a58 812208a0 00000200 80e128d4 80e128d4 8d4ae00c a8cd8600
 a8cd8094 9a3efd74 80935e0e 00000009 9a3efd6c 811d7fd3 9a3efd88 9a3efd9c
Call Trace:
  [<80faf273>] dump_stack+0x48/0x69
  [<80935dc9>] warn_slowpath_common+0x79/0x90
  [<80e128d4>] ? ion_handle_add+0xb4/0xc0
  [<80e128d4>] ? ion_handle_add+0xb4/0xc0
  [<80935e0e>] warn_slowpath_fmt+0x2e/0x30
  [<80e128d4>] ion_handle_add+0xb4/0xc0
  [<80e144cc>] ion_import_dma_buf+0x8c/0x110
  [<80c517c4>] reg_init+0x364/0x7d0
  [<80993363>] ? futex_wait+0x123/0x210
  [<80992e0e>] ? get_futex_key+0x16e/0x1e0
  [<8099308f>] ? futex_wake+0x5f/0x120
  [<80c51e19>] vpu_service_ioctl+0x1e9/0x500
  [<80994aec>] ? do_futex+0xec/0x8e0
  [<80971080>] ? prepare_to_wait_event+0xc0/0xc0
  [<80c51c30>] ? reg_init+0x7d0/0x7d0
  [<80a22562>] do_vfs_ioctl+0x2d2/0x4c0
  [<80b198ad>] ? inode_has_perm.isra.41+0x2d/0x40
  [<80b199cf>] ? file_has_perm+0x7f/0x90
  [<80b1a5f7>] ? selinux_file_ioctl+0x47/0xf0
  [<80a227a8>] SyS_ioctl+0x58/0x80
  [<80fb45e8>] syscall_call+0x7/0x7
  [<80fb0000>] ? mmc_do_calc_max_discard+0xab/0xe4

Fixes: 83271f6 ("ion: hold reference to handle...")
Signed-off-by: Shawn Lin <[email protected]>
Reviewed-by: Laura Abbott <[email protected]>
Cc: stable <[email protected]> # 3.14+
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Git-commit: 6fa92e2
Git-repo: https://android.googlesource.com/kernel/common/
Change-Id: I98d3e8fa0d58ad5138d197edc5d4869f625a9f9b
Signed-off-by: Patrick Daly <[email protected]>
leonfish77101 pushed a commit that referenced this pull request Nov 15, 2016
we found this issue but still exit in lastest kernel. Simply
keep ion_handle_create under mutex_lock to avoid this race.

WARNING: CPU: 2 PID: 2648 at drivers/staging/android/ion/ion.c:512 ion_handle_add+0xb4/0xc0()
ion_handle_add: buffer already found.
Modules linked in: iwlmvm iwlwifi mac80211 cfg80211 compat
CPU: 2 PID: 2648 Comm: TimedEventQueue Tainted: G        W    3.14.0 #7
 00000000 00000000 9a3efd2c 80faf273 9a3efd6c 9a3efd5c 80935dc9 811d7fd3
 9a3efd88 00000a58 812208a0 00000200 80e128d4 80e128d4 8d4ae00c a8cd8600
 a8cd8094 9a3efd74 80935e0e 00000009 9a3efd6c 811d7fd3 9a3efd88 9a3efd9c
Call Trace:
  [<80faf273>] dump_stack+0x48/0x69
  [<80935dc9>] warn_slowpath_common+0x79/0x90
  [<80e128d4>] ? ion_handle_add+0xb4/0xc0
  [<80e128d4>] ? ion_handle_add+0xb4/0xc0
  [<80935e0e>] warn_slowpath_fmt+0x2e/0x30
  [<80e128d4>] ion_handle_add+0xb4/0xc0
  [<80e144cc>] ion_import_dma_buf+0x8c/0x110
  [<80c517c4>] reg_init+0x364/0x7d0
  [<80993363>] ? futex_wait+0x123/0x210
  [<80992e0e>] ? get_futex_key+0x16e/0x1e0
  [<8099308f>] ? futex_wake+0x5f/0x120
  [<80c51e19>] vpu_service_ioctl+0x1e9/0x500
  [<80994aec>] ? do_futex+0xec/0x8e0
  [<80971080>] ? prepare_to_wait_event+0xc0/0xc0
  [<80c51c30>] ? reg_init+0x7d0/0x7d0
  [<80a22562>] do_vfs_ioctl+0x2d2/0x4c0
  [<80b198ad>] ? inode_has_perm.isra.41+0x2d/0x40
  [<80b199cf>] ? file_has_perm+0x7f/0x90
  [<80b1a5f7>] ? selinux_file_ioctl+0x47/0xf0
  [<80a227a8>] SyS_ioctl+0x58/0x80
  [<80fb45e8>] syscall_call+0x7/0x7
  [<80fb0000>] ? mmc_do_calc_max_discard+0xab/0xe4

Fixes: 83271f6 ("ion: hold reference to handle...")
Signed-off-by: Shawn Lin <[email protected]>
Reviewed-by: Laura Abbott <[email protected]>
Cc: stable <[email protected]> # 3.14+
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Git-commit: 6fa92e2
Git-repo: https://android.googlesource.com/kernel/common/
Change-Id: I98d3e8fa0d58ad5138d197edc5d4869f625a9f9b
Signed-off-by: Patrick Daly <[email protected]>
NewEraCracker pushed a commit to NewEraCracker/android_kernel_oneplus_msm8996 that referenced this pull request Jul 13, 2017
[ Upstream commit c70b17b775edb21280e9de7531acf6db3b365274 ]

Reducing real_num_tx_queues needs to be in sync with skb queue_mapping
otherwise skbs with queue_mapping greater than real_num_tx_queues
can be sent to the underlying driver and can result in kernel panic.

One such event is running netconsole and enabling VF on the same
device. Or running netconsole and changing number of tx queues via
ethtool on same device.

e.g.
Unable to handle kernel NULL pointer dereference
tsk->{mm,active_mm}->context = 0000000000001525
tsk->{mm,active_mm}->pgd = fff800130ff9a000
              \|/ ____ \|/
              "@'/ .. \`@"
              /_| \__/ |_\
                 \__U_/
kworker/48:1(475): Oops [OnePlusOSS#1]
CPU: 48 PID: 475 Comm: kworker/48:1 Tainted: G           OE
4.11.0-rc3-davem-net+ OnePlusOSS#7
Workqueue: events queue_process
task: fff80013113299c0 task.stack: fff800131132c000
TSTATE: 0000004480e01600 TPC: 00000000103f9e3c TNPC: 00000000103f9e40 Y:
00000000    Tainted: G           OE
TPC: <ixgbe_xmit_frame_ring+0x7c/0x6c0 [ixgbe]>
g0: 0000000000000000 g1: 0000000000003fff g2: 0000000000000000 g3:
0000000000000001
g4: fff80013113299c0 g5: fff8001fa6808000 g6: fff800131132c000 g7:
00000000000000c0
o0: fff8001fa760c460 o1: fff8001311329a50 o2: fff8001fa7607504 o3:
0000000000000003
o4: fff8001f96e63a40 o5: fff8001311d77ec0 sp: fff800131132f0e1 ret_pc:
000000000049ed94
RPC: <set_next_entity+0x34/0xb80>
l0: 0000000000000000 l1: 0000000000000800 l2: 0000000000000000 l3:
0000000000000000
l4: 000b2aa30e34b10d l5: 0000000000000000 l6: 0000000000000000 l7:
fff8001fa7605028
i0: fff80013111a8a00 i1: fff80013155a0780 i2: 0000000000000000 i3:
0000000000000000
i4: 0000000000000000 i5: 0000000000100000 i6: fff800131132f1a1 i7:
00000000103fa4b0
I7: <ixgbe_xmit_frame+0x30/0xa0 [ixgbe]>
Call Trace:
 [00000000103fa4b0] ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
 [0000000000998c74] netpoll_start_xmit+0xf4/0x200
 [0000000000998e10] queue_process+0x90/0x160
 [0000000000485fa8] process_one_work+0x188/0x480
 [0000000000486410] worker_thread+0x170/0x4c0
 [000000000048c6b8] kthread+0xd8/0x120
 [0000000000406064] ret_from_fork+0x1c/0x2c
 [0000000000000000]           (null)
Disabling lock debugging due to kernel taint
Caller[00000000103fa4b0]: ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
Caller[0000000000998c74]: netpoll_start_xmit+0xf4/0x200
Caller[0000000000998e10]: queue_process+0x90/0x160
Caller[0000000000485fa8]: process_one_work+0x188/0x480
Caller[0000000000486410]: worker_thread+0x170/0x4c0
Caller[000000000048c6b8]: kthread+0xd8/0x120
Caller[0000000000406064]: ret_from_fork+0x1c/0x2c
Caller[0000000000000000]:           (null)

Signed-off-by: Tushar Dave <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Martinusbe referenced this pull request in GZR-Kernels/kernel_oneplus_msm8996 Jul 24, 2017
[ Upstream commit c70b17b775edb21280e9de7531acf6db3b365274 ]

Reducing real_num_tx_queues needs to be in sync with skb queue_mapping
otherwise skbs with queue_mapping greater than real_num_tx_queues
can be sent to the underlying driver and can result in kernel panic.

One such event is running netconsole and enabling VF on the same
device. Or running netconsole and changing number of tx queues via
ethtool on same device.

e.g.
Unable to handle kernel NULL pointer dereference
tsk->{mm,active_mm}->context = 0000000000001525
tsk->{mm,active_mm}->pgd = fff800130ff9a000
              \|/ ____ \|/
              "@'/ .. \`@"
              /_| \__/ |_\
                 \__U_/
kworker/48:1(475): Oops [#1]
CPU: 48 PID: 475 Comm: kworker/48:1 Tainted: G           OE
4.11.0-rc3-davem-net+ #7
Workqueue: events queue_process
task: fff80013113299c0 task.stack: fff800131132c000
TSTATE: 0000004480e01600 TPC: 00000000103f9e3c TNPC: 00000000103f9e40 Y:
00000000    Tainted: G           OE
TPC: <ixgbe_xmit_frame_ring+0x7c/0x6c0 [ixgbe]>
g0: 0000000000000000 g1: 0000000000003fff g2: 0000000000000000 g3:
0000000000000001
g4: fff80013113299c0 g5: fff8001fa6808000 g6: fff800131132c000 g7:
00000000000000c0
o0: fff8001fa760c460 o1: fff8001311329a50 o2: fff8001fa7607504 o3:
0000000000000003
o4: fff8001f96e63a40 o5: fff8001311d77ec0 sp: fff800131132f0e1 ret_pc:
000000000049ed94
RPC: <set_next_entity+0x34/0xb80>
l0: 0000000000000000 l1: 0000000000000800 l2: 0000000000000000 l3:
0000000000000000
l4: 000b2aa30e34b10d l5: 0000000000000000 l6: 0000000000000000 l7:
fff8001fa7605028
i0: fff80013111a8a00 i1: fff80013155a0780 i2: 0000000000000000 i3:
0000000000000000
i4: 0000000000000000 i5: 0000000000100000 i6: fff800131132f1a1 i7:
00000000103fa4b0
I7: <ixgbe_xmit_frame+0x30/0xa0 [ixgbe]>
Call Trace:
 [00000000103fa4b0] ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
 [0000000000998c74] netpoll_start_xmit+0xf4/0x200
 [0000000000998e10] queue_process+0x90/0x160
 [0000000000485fa8] process_one_work+0x188/0x480
 [0000000000486410] worker_thread+0x170/0x4c0
 [000000000048c6b8] kthread+0xd8/0x120
 [0000000000406064] ret_from_fork+0x1c/0x2c
 [0000000000000000]           (null)
Disabling lock debugging due to kernel taint
Caller[00000000103fa4b0]: ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
Caller[0000000000998c74]: netpoll_start_xmit+0xf4/0x200
Caller[0000000000998e10]: queue_process+0x90/0x160
Caller[0000000000485fa8]: process_one_work+0x188/0x480
Caller[0000000000486410]: worker_thread+0x170/0x4c0
Caller[000000000048c6b8]: kthread+0xd8/0x120
Caller[0000000000406064]: ret_from_fork+0x1c/0x2c
Caller[0000000000000000]:           (null)

Signed-off-by: Tushar Dave <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Martinusbe <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request Jan 22, 2018
commit 624f5ab8720b3371367327a822c267699c1823b8 upstream.

syzkaller reported a NULL pointer dereference in asn1_ber_decoder().  It
can be reproduced by the following command, assuming
CONFIG_PKCS7_TEST_KEY=y:

        keyctl add pkcs7_test desc '' @s

The bug is that if the data buffer is empty, an integer underflow occurs
in the following check:

        if (unlikely(dp >= datalen - 1))
                goto data_overrun_error;

This results in the NULL data pointer being dereferenced.

Fix it by checking for 'datalen - dp < 2' instead.

Also fix the similar check for 'dp >= datalen - n' later in the same
function.  That one possibly could result in a buffer overread.

The NULL pointer dereference was reproducible using the "pkcs7_test" key
type but not the "asymmetric" key type because the "asymmetric" key type
checks for a 0-length payload before calling into the ASN.1 decoder but
the "pkcs7_test" key type does not.

The bug report was:

    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    PGD 7b708067 P4D 7b708067 PUD 7b6ee067 PMD 0
    Oops: 0000 [#1] SMP
    Modules linked in:
    CPU: 0 PID: 522 Comm: syz-executor1 Not tainted 4.14.0-rc8 OnePlusOSS#7
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.3-20171021_125229-anatol 04/01/2014
    task: ffff9b6b3798c040 task.stack: ffff9b6b37970000
    RIP: 0010:asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    RSP: 0018:ffff9b6b37973c78 EFLAGS: 00010216
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000021c
    RDX: ffffffff814a04ed RSI: ffffb1524066e000 RDI: ffffffff910759e0
    RBP: ffff9b6b37973d60 R08: 0000000000000001 R09: ffff9b6b3caa4180
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
    R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
    FS:  00007f10ed1f2700(0000) GS:ffff9b6b3ea00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000007b6f3000 CR4: 00000000000006f0
    Call Trace:
     pkcs7_parse_message+0xee/0x240 crypto/asymmetric_keys/pkcs7_parser.c:139
     verify_pkcs7_signature+0x33/0x180 certs/system_keyring.c:216
     pkcs7_preparse+0x41/0x70 crypto/asymmetric_keys/pkcs7_key_type.c:63
     key_create_or_update+0x180/0x530 security/keys/key.c:855
     SYSC_add_key security/keys/keyctl.c:122 [inline]
     SyS_add_key+0xbf/0x250 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0xbe
    RIP: 0033:0x4585c9
    RSP: 002b:00007f10ed1f1bd8 EFLAGS: 00000216 ORIG_RAX: 00000000000000f8
    RAX: ffffffffffffffda RBX: 00007f10ed1f2700 RCX: 00000000004585c9
    RDX: 0000000020000000 RSI: 0000000020008ffb RDI: 0000000020008000
    RBP: 0000000000000000 R08: ffffffffffffffff R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000216 R12: 00007fff1b2260ae
    R13: 00007fff1b2260af R14: 00007f10ed1f2700 R15: 0000000000000000
    Code: dd ca ff 48 8b 45 88 48 83 e8 01 4c 39 f0 0f 86 a8 07 00 00 e8 53 dd ca ff 49 8d 46 01 48 89 85 58 ff ff ff 48 8b 85 60 ff ff ff <42> 0f b6 0c 30 89 c8 88 8d 75 ff ff ff 83 e0 1f 89 8d 28 ff ff
    RIP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233 RSP: ffff9b6b37973c78
    CR2: 0000000000000000

Fixes: 42d5ec2 ("X.509: Add an ASN.1 decoder")
Reported-by: syzbot <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: James Morris <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request Apr 10, 2018
[ Upstream commit d754941225a7dbc61f6dd2173fa9498049f9a7ee ]

If, for any reason, userland shuts down iscsi transport interfaces
before proper logouts - like when logging in to LUNs manually, without
logging out on server shutdown, or when automated scripts can't
umount/logout from logged LUNs - kernel will hang forever on its
sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all
still existent paths.

PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow"
 #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee
 #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5
 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199
 OnePlusOSS#3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604
 OnePlusOSS#4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c
 OnePlusOSS#5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10
 OnePlusOSS#6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7
 OnePlusOSS#7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe
 OnePlusOSS#8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7
 OnePlusOSS#9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c

This happens because iscsi_eh_cmd_timed_out(), the transport layer
timeout helper, would tell the queue timeout function (scsi_times_out)
to reset the request timer over and over, until the session state is
back to logged in state. Unfortunately, during server shutdown, this
might never happen again.

Other option would be "not to handle" the issue in the transport
layer. That would trigger the error handler logic, which would also need
the session state to be logged in again.

Best option, for such case, is to tell upper layers that the command was
handled during the transport layer error handler helper, marking it as
DID_NO_CONNECT, which will allow completion and inform about the
problem.

After the session was marked as ISCSI_STATE_FAILED, due to the first
timeout during the server shutdown phase, all subsequent cmds will fail
to be queued, allowing upper logic to fail faster.

Signed-off-by: Rafael David Tinoco <[email protected]>
Reviewed-by: Lee Duncan <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request Apr 13, 2018
[ Upstream commit d754941225a7dbc61f6dd2173fa9498049f9a7ee ]

If, for any reason, userland shuts down iscsi transport interfaces
before proper logouts - like when logging in to LUNs manually, without
logging out on server shutdown, or when automated scripts can't
umount/logout from logged LUNs - kernel will hang forever on its
sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all
still existent paths.

PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow"
 #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee
 #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5
 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199
 OnePlusOSS#3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604
 OnePlusOSS#4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c
 OnePlusOSS#5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10
 OnePlusOSS#6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7
 OnePlusOSS#7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe
 OnePlusOSS#8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7
 OnePlusOSS#9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c

This happens because iscsi_eh_cmd_timed_out(), the transport layer
timeout helper, would tell the queue timeout function (scsi_times_out)
to reset the request timer over and over, until the session state is
back to logged in state. Unfortunately, during server shutdown, this
might never happen again.

Other option would be "not to handle" the issue in the transport
layer. That would trigger the error handler logic, which would also need
the session state to be logged in again.

Best option, for such case, is to tell upper layers that the command was
handled during the transport layer error handler helper, marking it as
DID_NO_CONNECT, which will allow completion and inform about the
problem.

After the session was marked as ISCSI_STATE_FAILED, due to the first
timeout during the server shutdown phase, all subsequent cmds will fail
to be queued, allowing upper logic to fail faster.

Signed-off-by: Rafael David Tinoco <[email protected]>
Reviewed-by: Lee Duncan <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request May 30, 2018
[ Upstream commit 2bbea6e117357d17842114c65e9a9cf2d13ae8a3 ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 OnePlusOSS#3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 OnePlusOSS#4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 OnePlusOSS#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 OnePlusOSS#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 OnePlusOSS#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 OnePlusOSS#8 [ffff880078447da8] mount_bdev at ffffffff81202570
 OnePlusOSS#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
OnePlusOSS#10 [ffff880078447e28] mount_fs at ffffffff81202d09
OnePlusOSS#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
OnePlusOSS#12 [ffff880078447ea8] do_mount at ffffffff81220fee
OnePlusOSS#13 [ffff880078447f28] sys_mount at ffffffff812218d6
OnePlusOSS#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 OnePlusOSS#3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 OnePlusOSS#4 [ffff8800784179d0] down_read at ffffffff8168cde0
 OnePlusOSS#5 [ffff8800784179e8] get_super at ffffffff81201cc7
 OnePlusOSS#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 OnePlusOSS#7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 OnePlusOSS#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 OnePlusOSS#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
OnePlusOSS#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
OnePlusOSS#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
OnePlusOSS#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
OnePlusOSS#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
OnePlusOSS#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
OnePlusOSS#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
OnePlusOSS#16 [ffff880078417d00] do_last at ffffffff8120d53d
OnePlusOSS#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
OnePlusOSS#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
OnePlusOSS#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
OnePlusOSS#20 [ffff880078417f70] sys_open at ffffffff811fde4e
OnePlusOSS#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request Aug 9, 2018
commit 89da619bc18d79bca5304724c11d4ba3b67ce2c6 upstream.

Kernel panic when with high memory pressure, calltrace looks like,

PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
 #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
 #1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
 #2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
 OnePlusOSS#3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
 OnePlusOSS#4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
 OnePlusOSS#5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
 OnePlusOSS#6 [ffff881ec7ed7838] __node_set at ffffffff81680300
 OnePlusOSS#7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
 OnePlusOSS#8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
 OnePlusOSS#9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
    [exception RIP: _raw_spin_lock_irqsave+47]
    RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
    RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
    RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
    RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
    R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
    R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

It happens in the pagefault and results in double pagefault
during compacting pages when memory allocation fails.

Analysed the vmcore, the page leads to second pagefault is corrupted
with _mapcount=-256, but private=0.

It's caused by the race between migration and ballooning, and lock
missing in virtballoon_migratepage() of virtio_balloon driver.
This patch fix the bug.

Fixes: e225042 ("virtio_balloon: introduce migration primitives to balloon pages")
Cc: [email protected]
Signed-off-by: Jiang Biao <[email protected]>
Signed-off-by: Huang Chong <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request Sep 5, 2018
[ Upstream commit 934140ab028713a61de8bca58c05332416d037d1 ]

cachefiles_read_waiter() has the right to access a 'monitor' object by
virtue of being called under the waitqueue lock for one of the pages in its
purview.  However, it has no ref on that monitor object or on the
associated operation.

What it is allowed to do is to move the monitor object to the operation's
to_do list, but once it drops the work_lock, it's actually no longer
permitted to access that object.  However, it is trying to enqueue the
retrieval operation for processing - but it can only do this via a pointer
in the monitor object, something it shouldn't be doing.

If it doesn't enqueue the operation, the operation may not get processed.
If the order is flipped so that the enqueue is first, then it's possible
for the work processor to look at the to_do list before the monitor is
enqueued upon it.

Fix this by getting a ref on the operation so that we can trust that it
will still be there once we've added the monitor to the to_do list and
dropped the work_lock.  The op can then be enqueued after the lock is
dropped.

The bug can manifest in one of a couple of ways.  The first manifestation
looks like:

 FS-Cache:
 FS-Cache: Assertion failed
 FS-Cache: 6 == 5 is false
 ------------[ cut here ]------------
 kernel BUG at fs/fscache/operation.c:494!
 RIP: 0010:fscache_put_operation+0x1e3/0x1f0
 ...
 fscache_op_work_func+0x26/0x50
 process_one_work+0x131/0x290
 worker_thread+0x45/0x360
 kthread+0xf8/0x130
 ? create_worker+0x190/0x190
 ? kthread_cancel_work_sync+0x10/0x10
 ret_from_fork+0x1f/0x30

This is due to the operation being in the DEAD state (6) rather than
INITIALISED, COMPLETE or CANCELLED (5) because it's already passed through
fscache_put_operation().

The bug can also manifest like the following:

 kernel BUG at fs/fscache/operation.c:69!
 ...
    [exception RIP: fscache_enqueue_operation+246]
 ...
 OnePlusOSS#7 [ffff883fff083c10] fscache_enqueue_operation at ffffffffa0b793c6
 OnePlusOSS#8 [ffff883fff083c28] cachefiles_read_waiter at ffffffffa0b15a48
 OnePlusOSS#9 [ffff883fff083c48] __wake_up_common at ffffffff810af028

I'm not entirely certain as to which is line 69 in Lei's kernel, so I'm not
entirely clear which assertion failed.

Fixes: 9ae326a ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Lei Xue <[email protected]>
Reported-by: Vegard Nossum <[email protected]>
Reported-by: Anthony DeRobertis <[email protected]>
Reported-by: NeilBrown <[email protected]>
Reported-by: Daniel Axtens <[email protected]>
Reported-by: Kiran Kumar Modukuri <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Daniel Axtens <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Slim80 pushed a commit to Slim80/android_kernel_oneplus_msm8996 that referenced this pull request Sep 11, 2018
[ Upstream commit 934140ab028713a61de8bca58c05332416d037d1 ]

cachefiles_read_waiter() has the right to access a 'monitor' object by
virtue of being called under the waitqueue lock for one of the pages in its
purview.  However, it has no ref on that monitor object or on the
associated operation.

What it is allowed to do is to move the monitor object to the operation's
to_do list, but once it drops the work_lock, it's actually no longer
permitted to access that object.  However, it is trying to enqueue the
retrieval operation for processing - but it can only do this via a pointer
in the monitor object, something it shouldn't be doing.

If it doesn't enqueue the operation, the operation may not get processed.
If the order is flipped so that the enqueue is first, then it's possible
for the work processor to look at the to_do list before the monitor is
enqueued upon it.

Fix this by getting a ref on the operation so that we can trust that it
will still be there once we've added the monitor to the to_do list and
dropped the work_lock.  The op can then be enqueued after the lock is
dropped.

The bug can manifest in one of a couple of ways.  The first manifestation
looks like:

 FS-Cache:
 FS-Cache: Assertion failed
 FS-Cache: 6 == 5 is false
 ------------[ cut here ]------------
 kernel BUG at fs/fscache/operation.c:494!
 RIP: 0010:fscache_put_operation+0x1e3/0x1f0
 ...
 fscache_op_work_func+0x26/0x50
 process_one_work+0x131/0x290
 worker_thread+0x45/0x360
 kthread+0xf8/0x130
 ? create_worker+0x190/0x190
 ? kthread_cancel_work_sync+0x10/0x10
 ret_from_fork+0x1f/0x30

This is due to the operation being in the DEAD state (6) rather than
INITIALISED, COMPLETE or CANCELLED (5) because it's already passed through
fscache_put_operation().

The bug can also manifest like the following:

 kernel BUG at fs/fscache/operation.c:69!
 ...
    [exception RIP: fscache_enqueue_operation+246]
 ...
 OnePlusOSS#7 [ffff883fff083c10] fscache_enqueue_operation at ffffffffa0b793c6
 OnePlusOSS#8 [ffff883fff083c28] cachefiles_read_waiter at ffffffffa0b15a48
 OnePlusOSS#9 [ffff883fff083c48] __wake_up_common at ffffffff810af028

I'm not entirely certain as to which is line 69 in Lei's kernel, so I'm not
entirely clear which assertion failed.

Fixes: 9ae326a ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Lei Xue <[email protected]>
Reported-by: Vegard Nossum <[email protected]>
Reported-by: Anthony DeRobertis <[email protected]>
Reported-by: NeilBrown <[email protected]>
Reported-by: Daniel Axtens <[email protected]>
Reported-by: Kiran Kumar Modukuri <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Daniel Axtens <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request Dec 17, 2018
[ Upstream commit c5a94f434c82529afda290df3235e4d85873c5b4 ]

It was observed that a process blocked indefintely in
__fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP
to be cleared via fscache_wait_for_deferred_lookup().

At this time, ->backing_objects was empty, which would normaly prevent
__fscache_read_or_alloc_page() from getting to the point of waiting.
This implies that ->backing_objects was cleared *after*
__fscache_read_or_alloc_page was was entered.

When an object is "killed" and then "dropped",
FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then
KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is
->backing_objects cleared.  This leaves a window where
something else can set FSCACHE_COOKIE_LOOKING_UP and
__fscache_read_or_alloc_page() can start waiting, before
->backing_objects is cleared

There is some uncertainty in this analysis, but it seems to be fit the
observations.  Adding the wake in this patch will be handled correctly
by __fscache_read_or_alloc_page(), as it checks if ->backing_objects
is empty again, after waiting.

Customer which reported the hang, also report that the hang cannot be
reproduced with this fix.

The backtrace for the blocked process looked like:

PID: 29360  TASK: ffff881ff2ac0f80  CPU: 3   COMMAND: "zsh"
 #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1
 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed
 #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8
 OnePlusOSS#3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e
 OnePlusOSS#4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache]
 OnePlusOSS#5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache]
 OnePlusOSS#6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs]
 OnePlusOSS#7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs]
 OnePlusOSS#8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73
 OnePlusOSS#9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs]
OnePlusOSS#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756
OnePlusOSS#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa
OnePlusOSS#12 [ffff881ff43eff18] sys_read at ffffffff811fda62
OnePlusOSS#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e

Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Slim80 pushed a commit to Slim80/android_kernel_oneplus_msm8996 that referenced this pull request Dec 26, 2018
[ Upstream commit c5a94f434c82529afda290df3235e4d85873c5b4 ]

It was observed that a process blocked indefintely in
__fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP
to be cleared via fscache_wait_for_deferred_lookup().

At this time, ->backing_objects was empty, which would normaly prevent
__fscache_read_or_alloc_page() from getting to the point of waiting.
This implies that ->backing_objects was cleared *after*
__fscache_read_or_alloc_page was was entered.

When an object is "killed" and then "dropped",
FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then
KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is
->backing_objects cleared.  This leaves a window where
something else can set FSCACHE_COOKIE_LOOKING_UP and
__fscache_read_or_alloc_page() can start waiting, before
->backing_objects is cleared

There is some uncertainty in this analysis, but it seems to be fit the
observations.  Adding the wake in this patch will be handled correctly
by __fscache_read_or_alloc_page(), as it checks if ->backing_objects
is empty again, after waiting.

Customer which reported the hang, also report that the hang cannot be
reproduced with this fix.

The backtrace for the blocked process looked like:

PID: 29360  TASK: ffff881ff2ac0f80  CPU: 3   COMMAND: "zsh"
 #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1
 OnePlusOSS#1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed
 OnePlusOSS#2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8
 OnePlusOSS#3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e
 OnePlusOSS#4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache]
 OnePlusOSS#5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache]
 OnePlusOSS#6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs]
 OnePlusOSS#7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs]
 OnePlusOSS#8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73
 OnePlusOSS#9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs]
OnePlusOSS#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756
OnePlusOSS#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa
OnePlusOSS#12 [ffff881ff43eff18] sys_read at ffffffff811fda62
OnePlusOSS#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e

Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Mar 21, 2019
As Jiqun Li reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202883

sometimes, dead lock when make system call SYS_getdents64 with fsync() is
called by another process.

monkey running on android9.0

1.  task 9785 held sbi->cp_rwsem and waiting lock_page()
2.  task 10349 held mm_sem and waiting sbi->cp_rwsem
3. task 9709 held lock_page() and waiting mm_sem

so this is a dead lock scenario.

task stack is show by crash tools as following

crash_arm64> bt ffffffc03c354080
PID: 9785   TASK: ffffffc03c354080  CPU: 1   COMMAND: "RxIoScheduler-3"
>> OnePlusOSS#7 [ffffffc01b50fac0] __lock_page at ffffff80081b11e8

crash-arm64> bt 10349
PID: 10349  TASK: ffffffc018b83080  CPU: 1   COMMAND: "BUGLY_ASYNC_UPL"
>> OnePlusOSS#3 [ffffffc01f8cfa40] rwsem_down_read_failed at ffffff8008a93afc
     PC: 00000033  LR: 00000000  SP: 00000000  PSTATE: ffffffffffffffff

crash-arm64> bt 9709
PID: 9709   TASK: ffffffc03e7f3080  CPU: 1   COMMAND: "IntentService[A"
>> OnePlusOSS#3 [ffffffc001e67850] rwsem_down_read_failed at ffffff8008a93afc
>> OnePlusOSS#8 [ffffffc001e67b80] el1_ia at ffffff8008084fc4
     PC: ffffff8008274114  [compat_filldir64+120]
     LR: ffffff80083584d4  [f2fs_fill_dentries+448]
     SP: ffffffc001e67b80  PSTATE: 80400145
    X29: ffffffc001e67b80  X28: 0000000000000000  X27: 000000000000001a
    X26: 00000000000093d7  X25: ffffffc070d52480  X24: 0000000000000008
    X23: 0000000000000028  X22: 00000000d43dfd60  X21: ffffffc001e67e90
    X20: 0000000000000011  X19: ffffff80093a4000  X18: 0000000000000000
    X17: 0000000000000000  X16: 0000000000000000  X15: 0000000000000000
    X14: ffffffffffffffff  X13: 0000000000000008  X12: 0101010101010101
    X11: 7f7f7f7f7f7f7f7f  X10: 6a6a6a6a6a6a6a6a   X9: 7f7f7f7f7f7f7f7f
     X8: 0000000080808000   X7: ffffff800827409c   X6: 0000000080808000
     X5: 0000000000000008   X4: 00000000000093d7   X3: 000000000000001a
     X2: 0000000000000011   X1: ffffffc070d52480   X0: 0000000000800238
>> OnePlusOSS#9 [ffffffc001e67be0] f2fs_fill_dentries at ffffff80083584d0
     PC: 0000003c  LR: 00000000  SP: 00000000  PSTATE: 000000d9
    X12: f48a02ff X11: d4678960 X10: d43dfc00  X9: d4678ae4
     X8: 00000058  X7: d4678994  X6: d43de800  X5: 000000d9
     X4: d43dfc0c  X3: d43dfc10  X2: d46799c8  X1: 00000000
     X0: 00001068

Below potential deadlock will happen between three threads:
Thread A		Thread B		Thread C
- f2fs_do_sync_file
 - f2fs_write_checkpoint
  - down_write(&sbi->node_change) -- 1)
			- do_page_fault
			 - down_write(&mm->mmap_sem) -- 2)
			  - do_wp_page
			   - f2fs_vm_page_mkwrite
						- getdents64
						 - f2fs_read_inline_dir
						  - lock_page -- 3)
  - f2fs_sync_node_pages
   - lock_page -- 3)
			    - __do_map_lock
			     - down_read(&sbi->node_change) -- 1)
						  - f2fs_fill_dentries
						   - dir_emit
						    - compat_filldir64
						     - do_page_fault
						      - down_read(&mm->mmap_sem) -- 2)

Since f2fs_readdir is protected by inode.i_rwsem, there should not be
any updates in inode page, we're safe to lookup dents in inode page
without its lock held, so taking off the lock to improve concurrency
of readdir and avoid potential deadlock.

Reported-by: Jiqun Li <[email protected]>
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
nathanchance pushed a commit to android-linux-stable/op3 that referenced this pull request Apr 27, 2019
[ Upstream commit d982b33133284fa7efa0e52ae06b88f9be3ea764 ]

  =================================================================
  ==20875==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 1160 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x55bd50005599 in zalloc util/util.h:23
      #2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
      OnePlusOSS#3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
      OnePlusOSS#4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
      OnePlusOSS#5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
      OnePlusOSS#6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
      OnePlusOSS#7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
      OnePlusOSS#8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
      OnePlusOSS#9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      OnePlusOSS#10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      OnePlusOSS#11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      OnePlusOSS#12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
      OnePlusOSS#13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 19 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: 6a6cd11 ("perf test: Add test for the sched tracepoint format fields")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request May 29, 2019
As Jiqun Li reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202883

sometimes, dead lock when make system call SYS_getdents64 with fsync() is
called by another process.

monkey running on android9.0

1.  task 9785 held sbi->cp_rwsem and waiting lock_page()
2.  task 10349 held mm_sem and waiting sbi->cp_rwsem
3. task 9709 held lock_page() and waiting mm_sem

so this is a dead lock scenario.

task stack is show by crash tools as following

crash_arm64> bt ffffffc03c354080
PID: 9785   TASK: ffffffc03c354080  CPU: 1   COMMAND: "RxIoScheduler-3"
>> OnePlusOSS#7 [ffffffc01b50fac0] __lock_page at ffffff80081b11e8

crash-arm64> bt 10349
PID: 10349  TASK: ffffffc018b83080  CPU: 1   COMMAND: "BUGLY_ASYNC_UPL"
>> OnePlusOSS#3 [ffffffc01f8cfa40] rwsem_down_read_failed at ffffff8008a93afc
     PC: 00000033  LR: 00000000  SP: 00000000  PSTATE: ffffffffffffffff

crash-arm64> bt 9709
PID: 9709   TASK: ffffffc03e7f3080  CPU: 1   COMMAND: "IntentService[A"
>> OnePlusOSS#3 [ffffffc001e67850] rwsem_down_read_failed at ffffff8008a93afc
>> OnePlusOSS#8 [ffffffc001e67b80] el1_ia at ffffff8008084fc4
     PC: ffffff8008274114  [compat_filldir64+120]
     LR: ffffff80083584d4  [f2fs_fill_dentries+448]
     SP: ffffffc001e67b80  PSTATE: 80400145
    X29: ffffffc001e67b80  X28: 0000000000000000  X27: 000000000000001a
    X26: 00000000000093d7  X25: ffffffc070d52480  X24: 0000000000000008
    X23: 0000000000000028  X22: 00000000d43dfd60  X21: ffffffc001e67e90
    X20: 0000000000000011  X19: ffffff80093a4000  X18: 0000000000000000
    X17: 0000000000000000  X16: 0000000000000000  X15: 0000000000000000
    X14: ffffffffffffffff  X13: 0000000000000008  X12: 0101010101010101
    X11: 7f7f7f7f7f7f7f7f  X10: 6a6a6a6a6a6a6a6a   X9: 7f7f7f7f7f7f7f7f
     X8: 0000000080808000   X7: ffffff800827409c   X6: 0000000080808000
     X5: 0000000000000008   X4: 00000000000093d7   X3: 000000000000001a
     X2: 0000000000000011   X1: ffffffc070d52480   X0: 0000000000800238
>> OnePlusOSS#9 [ffffffc001e67be0] f2fs_fill_dentries at ffffff80083584d0
     PC: 0000003c  LR: 00000000  SP: 00000000  PSTATE: 000000d9
    X12: f48a02ff X11: d4678960 X10: d43dfc00  X9: d4678ae4
     X8: 00000058  X7: d4678994  X6: d43de800  X5: 000000d9
     X4: d43dfc0c  X3: d43dfc10  X2: d46799c8  X1: 00000000
     X0: 00001068

Below potential deadlock will happen between three threads:
Thread A		Thread B		Thread C
- f2fs_do_sync_file
 - f2fs_write_checkpoint
  - down_write(&sbi->node_change) -- 1)
			- do_page_fault
			 - down_write(&mm->mmap_sem) -- 2)
			  - do_wp_page
			   - f2fs_vm_page_mkwrite
						- getdents64
						 - f2fs_read_inline_dir
						  - lock_page -- 3)
  - f2fs_sync_node_pages
   - lock_page -- 3)
			    - __do_map_lock
			     - down_read(&sbi->node_change) -- 1)
						  - f2fs_fill_dentries
						   - dir_emit
						    - compat_filldir64
						     - do_page_fault
						      - down_read(&mm->mmap_sem) -- 2)

Since f2fs_readdir is protected by inode.i_rwsem, there should not be
any updates in inode page, we're safe to lookup dents in inode page
without its lock held, so taking off the lock to improve concurrency
of readdir and avoid potential deadlock.

Reported-by: Jiqun Li <[email protected]>
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Sep 8, 2019
commit cf3591ef832915892f2499b7e54b51d4c578b28c upstream.

Revert the commit bd293d071ffe65e645b4d8104f9d8fe15ea13862. The proper
fix has been made available with commit d0a255e795ab ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d071ffe doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   OnePlusOSS#1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   OnePlusOSS#2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   OnePlusOSS#3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   OnePlusOSS#4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   OnePlusOSS#5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   OnePlusOSS#6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   OnePlusOSS#7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   OnePlusOSS#8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   OnePlusOSS#9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  OnePlusOSS#10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  OnePlusOSS#11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  OnePlusOSS#12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  OnePlusOSS#13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  OnePlusOSS#14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <[email protected]>
Cc: [email protected]
Fixes: bd293d071ffe ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e795ab ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Change-Id: I6cd6b254cca8cb8e72c197d44b91790c1a799554
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Nov 8, 2019
[ Upstream commit 347ab9480313737c0f1aaa08e8f2e1a791235535 ]

This patch fixes deadlock warning if removing PWM device
when CONFIG_PROVE_LOCKING is enabled.

This issue can be reproceduced by the following steps on
the R-Car H3 Salvator-X board if the backlight is disabled:

 # cd /sys/class/pwm/pwmchip0
 # echo 0 > export
 # ls
 device  export  npwm  power  pwm0  subsystem  uevent  unexport
 # cd device/driver
 # ls
 bind  e6e31000.pwm  uevent  unbind
 # echo e6e31000.pwm > unbind

[   87.659974] ======================================================
[   87.666149] WARNING: possible circular locking dependency detected
[   87.672327] 5.0.0 OnePlusOSS#7 Not tainted
[   87.675549] ------------------------------------------------------
[   87.681723] bash/2986 is trying to acquire lock:
[   87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0
[   87.694528]
[   87.694528] but task is already holding lock:
[   87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.707405]
[   87.707405] which lock already depends on the new lock.
[   87.707405]
[   87.715574]
[   87.715574] the existing dependency chain (in reverse order) is:
[   87.723048]
[   87.723048] -> OnePlusOSS#1 (pwm_lock){+.+.}:
[   87.728017]        __mutex_lock+0x70/0x7e4
[   87.732108]        mutex_lock_nested+0x1c/0x24
[   87.736547]        pwm_request_from_chip.part.6+0x34/0x74
[   87.741940]        pwm_request_from_chip+0x20/0x40
[   87.746725]        export_store+0x6c/0x1f4
[   87.750820]        dev_attr_store+0x18/0x28
[   87.754998]        sysfs_kf_write+0x54/0x64
[   87.759175]        kernfs_fop_write+0xe4/0x1e8
[   87.763615]        __vfs_write+0x40/0x184
[   87.767619]        vfs_write+0xa8/0x19c
[   87.771448]        ksys_write+0x58/0xbc
[   87.775278]        __arm64_sys_write+0x18/0x20
[   87.779721]        el0_svc_common+0xd0/0x124
[   87.783986]        el0_svc_compat_handler+0x1c/0x24
[   87.788858]        el0_svc_compat+0x8/0x18
[   87.792947]
[   87.792947] -> #0 (kn->count#58){++++}:
[   87.798260]        lock_acquire+0xc4/0x22c
[   87.802353]        __kernfs_remove+0x258/0x2c4
[   87.806790]        kernfs_remove_by_name_ns+0x50/0xa0
[   87.811836]        remove_files.isra.1+0x38/0x78
[   87.816447]        sysfs_remove_group+0x48/0x98
[   87.820971]        sysfs_remove_groups+0x34/0x4c
[   87.825583]        device_remove_attrs+0x6c/0x7c
[   87.830197]        device_del+0x11c/0x33c
[   87.834201]        device_unregister+0x14/0x2c
[   87.838638]        pwmchip_sysfs_unexport+0x40/0x4c
[   87.843509]        pwmchip_remove+0xf4/0x13c
[   87.847773]        rcar_pwm_remove+0x28/0x34
[   87.852039]        platform_drv_remove+0x24/0x64
[   87.856651]        device_release_driver_internal+0x18c/0x21c
[   87.862391]        device_release_driver+0x14/0x1c
[   87.867175]        unbind_store+0xe0/0x124
[   87.871265]        drv_attr_store+0x20/0x30
[   87.875442]        sysfs_kf_write+0x54/0x64
[   87.879618]        kernfs_fop_write+0xe4/0x1e8
[   87.884055]        __vfs_write+0x40/0x184
[   87.888057]        vfs_write+0xa8/0x19c
[   87.891887]        ksys_write+0x58/0xbc
[   87.895716]        __arm64_sys_write+0x18/0x20
[   87.900154]        el0_svc_common+0xd0/0x124
[   87.904417]        el0_svc_compat_handler+0x1c/0x24
[   87.909289]        el0_svc_compat+0x8/0x18
[   87.913378]
[   87.913378] other info that might help us debug this:
[   87.913378]
[   87.921374]  Possible unsafe locking scenario:
[   87.921374]
[   87.927286]        CPU0                    CPU1
[   87.931808]        ----                    ----
[   87.936331]   lock(pwm_lock);
[   87.939293]                                lock(kn->count#58);
[   87.945120]                                lock(pwm_lock);
[   87.950599]   lock(kn->count#58);
[   87.953908]
[   87.953908]  *** DEADLOCK ***
[   87.953908]
[   87.959821] 4 locks held by bash/2986:
[   87.963563]  #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c
[   87.971044]  OnePlusOSS#1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8
[   87.978872]  OnePlusOSS#2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c
[   87.988001]  OnePlusOSS#3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.995481]
[   87.995481] stack backtrace:
[   87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 OnePlusOSS#7
[   88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT)
[   88.012791] Call trace:
[   88.015235]  dump_backtrace+0x0/0x190
[   88.018891]  show_stack+0x14/0x1c
[   88.022204]  dump_stack+0xb0/0xec
[   88.025514]  print_circular_bug.isra.32+0x1d0/0x2e0
[   88.030385]  __lock_acquire+0x1318/0x1864
[   88.034388]  lock_acquire+0xc4/0x22c
[   88.037958]  __kernfs_remove+0x258/0x2c4
[   88.041874]  kernfs_remove_by_name_ns+0x50/0xa0
[   88.046398]  remove_files.isra.1+0x38/0x78
[   88.050487]  sysfs_remove_group+0x48/0x98
[   88.054490]  sysfs_remove_groups+0x34/0x4c
[   88.058580]  device_remove_attrs+0x6c/0x7c
[   88.062671]  device_del+0x11c/0x33c
[   88.066154]  device_unregister+0x14/0x2c
[   88.070070]  pwmchip_sysfs_unexport+0x40/0x4c
[   88.074421]  pwmchip_remove+0xf4/0x13c
[   88.078163]  rcar_pwm_remove+0x28/0x34
[   88.081906]  platform_drv_remove+0x24/0x64
[   88.085996]  device_release_driver_internal+0x18c/0x21c
[   88.091215]  device_release_driver+0x14/0x1c
[   88.095478]  unbind_store+0xe0/0x124
[   88.099048]  drv_attr_store+0x20/0x30
[   88.102704]  sysfs_kf_write+0x54/0x64
[   88.106359]  kernfs_fop_write+0xe4/0x1e8
[   88.110275]  __vfs_write+0x40/0x184
[   88.113757]  vfs_write+0xa8/0x19c
[   88.117065]  ksys_write+0x58/0xbc
[   88.120374]  __arm64_sys_write+0x18/0x20
[   88.124291]  el0_svc_common+0xd0/0x124
[   88.128034]  el0_svc_compat_handler+0x1c/0x24
[   88.132384]  el0_svc_compat+0x8/0x18

The sysfs unexport in pwmchip_remove() is completely asymmetric
to what we do in pwmchip_add_with_polarity() and commit 0733424c9ba9
("pwm: Unexport children before chip removal") is a strong indication
that this was wrong to begin with. We should just move
pwmchip_sysfs_unexport() where it belongs, which is right after
pwmchip_sysfs_unexport_children(). In that case, we do not need
separate functions anymore either.

We also really want to remove sysfs irrespective of whether or not
the chip will be removed as a result of pwmchip_remove(). We can only
assume that the driver will be gone after that, so we shouldn't leave
any dangling sysfs files around.

This warning disappears if we move pwmchip_sysfs_unexport() to
the top of pwmchip_remove(), pwmchip_sysfs_unexport_children().
That way it is also outside of the pwm_lock section, which indeed
doesn't seem to be needed.

Moving the pwmchip_sysfs_export() call outside of that section also
seems fine and it'd be perfectly symmetric with pwmchip_remove() again.

So, this patch fixes them.

Signed-off-by: Phong Hoang <[email protected]>
[shimoda: revise the commit log and code]
Fixes: 76abbdd ("pwm: Add sysfs interface")
Fixes: 0733424c9ba9 ("pwm: Unexport children before chip removal")
Signed-off-by: Yoshihiro Shimoda <[email protected]>
Tested-by: Hoan Nguyen An <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Uwe Kleine-König <[email protected]>
Signed-off-by: Thierry Reding <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: If7fc36ed28d5bd95a4f32666dc2010939cbf66e5
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Dec 22, 2019
[ Upstream commit 443f2d5ba13d65ccfd879460f77941875159d154 ]

Observe a segmentation fault when 'perf stat' is asked to repeat forever
with the interval option.

Without fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
  #           time             counts unit events
       5.000211692  3,13,89,82,34,157      cycles
      10.000380119  1,53,98,52,22,294      cycles
      10.040467280       17,16,79,265      cycles
  Segmentation fault

This problem was only observed when we use forever option aka -r 0 and
works with limited repeats. Calling print_counter with ts being set to
NULL, is not a correct option when interval is set. Hence avoid
print_counter(NULL,..)  if interval is set.

With fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
   #           time             counts unit events
       5.019866622  3,15,14,43,08,697      cycles
      10.039865756  3,15,16,31,95,261      cycles
      10.059950628     1,26,05,47,158      cycles
       5.009902655  3,14,52,62,33,932      cycles
      10.019880228  3,14,52,22,89,154      cycles
      10.030543876       66,90,18,333      cycles
       5.009848281  3,14,51,98,25,437      cycles
      10.029854402  3,15,14,93,04,918      cycles
       5.009834177  3,14,51,95,92,316      cycles

Committer notes:

Did the 'git bisect' to find the cset introducing the problem to add the
Fixes tag below, and at that time the problem reproduced as:

  (gdb) run stat -r0 -I500 sleep 1
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  866		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
  (gdb) bt
  #0  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  OnePlusOSS#1  0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938
  OnePlusOSS#2  0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411
  OnePlusOSS#3  0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370
  OnePlusOSS#4  0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429
  OnePlusOSS#5  0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473
  OnePlusOSS#6  0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588
  (gdb)

Mostly the same as just before this patch:

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  964		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep);
  (gdb) bt
  #0  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  OnePlusOSS#1  0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670)
      at util/stat-display.c:1172
  OnePlusOSS#2  0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656
  OnePlusOSS#3  0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960
  OnePlusOSS#4  0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310
  OnePlusOSS#5  0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362
  OnePlusOSS#6  0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406
  OnePlusOSS#7  0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531
  (gdb)

Fixes: d4f63a4 ("perf stat: Introduce print_counters function")
Signed-off-by: Srikar Dronamraju <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Tested-by: Ravi Bangoria <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Naveen N. Rao <[email protected]>
Cc: [email protected] # v4.2+
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I03e14a64d8f774e0cd166298744216ebe9fb26bc
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Mar 3, 2020
[ Upstream commit 42ffb0bf584ae5b6b38f72259af1e0ee417ac77f ]

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   OnePlusOSS#1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   OnePlusOSS#2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   OnePlusOSS#3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   OnePlusOSS#4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   OnePlusOSS#5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   OnePlusOSS#6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   OnePlusOSS#7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   OnePlusOSS#8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   OnePlusOSS#9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   OnePlusOSS#1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   OnePlusOSS#2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   OnePlusOSS#3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   OnePlusOSS#4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   OnePlusOSS#5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   OnePlusOSS#6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   OnePlusOSS#7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   OnePlusOSS#8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   OnePlusOSS#9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02 ("Btrfs: Add writepages support")
CC: [email protected] # 4.4+
Reviewed-by: Filipe Manana <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I5daee5ea01df5eb76df156cb489140e58826cab4
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Mar 5, 2020
[ Upstream commit 54155ed4199c7aa3fd20866648024ab63c96d579 ]

A faulty userspace that calls destroy_session() before destroying the
connections can trigger the failure.  This patch prevents the issue by
refusing to destroy the session if there are outstanding connections.

------------[ cut here ]------------
kernel BUG at mm/slub.c:306!
invalid opcode: 0000 [OnePlusOSS#1] SMP PTI
CPU: 1 PID: 1224 Comm: iscsid Not tainted 5.4.0-rc2.iscsi+ OnePlusOSS#7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:__slab_free+0x181/0x350
[...]
[ 1209.686056] RSP: 0018:ffffa93d4074fae0 EFLAGS: 00010246
[ 1209.686694] RAX: ffff934efa5ad800 RBX: 000000008010000a RCX: ffff934efa5ad800
[ 1209.687651] RDX: ffff934efa5ad800 RSI: ffffeb4041e96b00 RDI: ffff934efd402c40
[ 1209.688582] RBP: ffffa93d4074fb80 R08: 0000000000000001 R09: ffffffffbb5dfa26
[ 1209.689425] R10: ffff934efa5ad800 R11: 0000000000000001 R12: ffffeb4041e96b00
[ 1209.690285] R13: ffff934efa5ad800 R14: ffff934efd402c40 R15: 0000000000000000
[ 1209.691213] FS:  00007f7945dfb540(0000) GS:ffff934efda80000(0000) knlGS:0000000000000000
[ 1209.692316] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1209.693013] CR2: 000055877fd3da80 CR3: 0000000077384000 CR4: 00000000000006e0
[ 1209.693897] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1209.694773] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1209.695631] Call Trace:
[ 1209.695957]  ? __wake_up_common_lock+0x8a/0xc0
[ 1209.696712]  iscsi_pool_free+0x26/0x40
[ 1209.697263]  iscsi_session_teardown+0x2f/0xf0
[ 1209.698117]  iscsi_sw_tcp_session_destroy+0x45/0x60
[ 1209.698831]  iscsi_if_rx+0xd88/0x14e0
[ 1209.699370]  netlink_unicast+0x16f/0x200
[ 1209.699932]  netlink_sendmsg+0x21a/0x3e0
[ 1209.700446]  sock_sendmsg+0x4f/0x60
[ 1209.700902]  ___sys_sendmsg+0x2ae/0x320
[ 1209.701451]  ? cp_new_stat+0x150/0x180
[ 1209.701922]  __sys_sendmsg+0x59/0xa0
[ 1209.702357]  do_syscall_64+0x52/0x160
[ 1209.702812]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1209.703419] RIP: 0033:0x7f7946433914
[...]
[ 1209.706084] RSP: 002b:00007fffb99f2378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1209.706994] RAX: ffffffffffffffda RBX: 000055bc869eac20 RCX: 00007f7946433914
[ 1209.708082] RDX: 0000000000000000 RSI: 00007fffb99f2390 RDI: 0000000000000005
[ 1209.709120] RBP: 00007fffb99f2390 R08: 000055bc84fe9320 R09: 00007fffb99f1f07
[ 1209.710110] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000038
[ 1209.711085] R13: 000055bc8502306e R14: 0000000000000000 R15: 0000000000000000
 Modules linked in:
 ---[ end trace a2d933ede7f730d8 ]---

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Nick Black <[email protected]>
Co-developed-by: Salman Qazi <[email protected]>
Signed-off-by: Salman Qazi <[email protected]>
Co-developed-by: Junho Ryu <[email protected]>
Signed-off-by: Junho Ryu <[email protected]>
Co-developed-by: Khazhismel Kumykov <[email protected]>
Signed-off-by: Khazhismel Kumykov <[email protected]>
Co-developed-by: Gabriel Krisman Bertazi <[email protected]>
Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
Reviewed-by: Lee Duncan <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I6906a6593a01ddd315ff744843b61f9d50739697
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Mar 7, 2020
[ Upstream commit 42ffb0bf584ae5b6b38f72259af1e0ee417ac77f ]

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   OnePlusOSS#1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   OnePlusOSS#2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   OnePlusOSS#3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   OnePlusOSS#4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   OnePlusOSS#5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   OnePlusOSS#6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   OnePlusOSS#7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   OnePlusOSS#8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   OnePlusOSS#9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   OnePlusOSS#1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   OnePlusOSS#2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   OnePlusOSS#3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   OnePlusOSS#4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   OnePlusOSS#5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   OnePlusOSS#6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   OnePlusOSS#7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   OnePlusOSS#8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   OnePlusOSS#9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02 ("Btrfs: Add writepages support")
CC: [email protected] # 4.4+
Reviewed-by: Filipe Manana <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I5daee5ea01df5eb76df156cb489140e58826cab4
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Mar 7, 2020
[ Upstream commit 54155ed4199c7aa3fd20866648024ab63c96d579 ]

A faulty userspace that calls destroy_session() before destroying the
connections can trigger the failure.  This patch prevents the issue by
refusing to destroy the session if there are outstanding connections.

------------[ cut here ]------------
kernel BUG at mm/slub.c:306!
invalid opcode: 0000 [OnePlusOSS#1] SMP PTI
CPU: 1 PID: 1224 Comm: iscsid Not tainted 5.4.0-rc2.iscsi+ OnePlusOSS#7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:__slab_free+0x181/0x350
[...]
[ 1209.686056] RSP: 0018:ffffa93d4074fae0 EFLAGS: 00010246
[ 1209.686694] RAX: ffff934efa5ad800 RBX: 000000008010000a RCX: ffff934efa5ad800
[ 1209.687651] RDX: ffff934efa5ad800 RSI: ffffeb4041e96b00 RDI: ffff934efd402c40
[ 1209.688582] RBP: ffffa93d4074fb80 R08: 0000000000000001 R09: ffffffffbb5dfa26
[ 1209.689425] R10: ffff934efa5ad800 R11: 0000000000000001 R12: ffffeb4041e96b00
[ 1209.690285] R13: ffff934efa5ad800 R14: ffff934efd402c40 R15: 0000000000000000
[ 1209.691213] FS:  00007f7945dfb540(0000) GS:ffff934efda80000(0000) knlGS:0000000000000000
[ 1209.692316] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1209.693013] CR2: 000055877fd3da80 CR3: 0000000077384000 CR4: 00000000000006e0
[ 1209.693897] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1209.694773] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1209.695631] Call Trace:
[ 1209.695957]  ? __wake_up_common_lock+0x8a/0xc0
[ 1209.696712]  iscsi_pool_free+0x26/0x40
[ 1209.697263]  iscsi_session_teardown+0x2f/0xf0
[ 1209.698117]  iscsi_sw_tcp_session_destroy+0x45/0x60
[ 1209.698831]  iscsi_if_rx+0xd88/0x14e0
[ 1209.699370]  netlink_unicast+0x16f/0x200
[ 1209.699932]  netlink_sendmsg+0x21a/0x3e0
[ 1209.700446]  sock_sendmsg+0x4f/0x60
[ 1209.700902]  ___sys_sendmsg+0x2ae/0x320
[ 1209.701451]  ? cp_new_stat+0x150/0x180
[ 1209.701922]  __sys_sendmsg+0x59/0xa0
[ 1209.702357]  do_syscall_64+0x52/0x160
[ 1209.702812]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1209.703419] RIP: 0033:0x7f7946433914
[...]
[ 1209.706084] RSP: 002b:00007fffb99f2378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1209.706994] RAX: ffffffffffffffda RBX: 000055bc869eac20 RCX: 00007f7946433914
[ 1209.708082] RDX: 0000000000000000 RSI: 00007fffb99f2390 RDI: 0000000000000005
[ 1209.709120] RBP: 00007fffb99f2390 R08: 000055bc84fe9320 R09: 00007fffb99f1f07
[ 1209.710110] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000038
[ 1209.711085] R13: 000055bc8502306e R14: 0000000000000000 R15: 0000000000000000
 Modules linked in:
 ---[ end trace a2d933ede7f730d8 ]---

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Nick Black <[email protected]>
Co-developed-by: Salman Qazi <[email protected]>
Signed-off-by: Salman Qazi <[email protected]>
Co-developed-by: Junho Ryu <[email protected]>
Signed-off-by: Junho Ryu <[email protected]>
Co-developed-by: Khazhismel Kumykov <[email protected]>
Signed-off-by: Khazhismel Kumykov <[email protected]>
Co-developed-by: Gabriel Krisman Bertazi <[email protected]>
Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
Reviewed-by: Lee Duncan <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I6906a6593a01ddd315ff744843b61f9d50739697
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Mar 22, 2020
[ Upstream commit 42ffb0bf584ae5b6b38f72259af1e0ee417ac77f ]

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   OnePlusOSS#1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   OnePlusOSS#2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   OnePlusOSS#3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   OnePlusOSS#4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   OnePlusOSS#5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   OnePlusOSS#6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   OnePlusOSS#7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   OnePlusOSS#8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   OnePlusOSS#9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   OnePlusOSS#1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   OnePlusOSS#2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   OnePlusOSS#3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   OnePlusOSS#4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   OnePlusOSS#5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   OnePlusOSS#6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   OnePlusOSS#7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   OnePlusOSS#8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   OnePlusOSS#9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02 ("Btrfs: Add writepages support")
CC: [email protected] # 4.4+
Reviewed-by: Filipe Manana <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I5daee5ea01df5eb76df156cb489140e58826cab4
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Mar 22, 2020
[ Upstream commit 54155ed4199c7aa3fd20866648024ab63c96d579 ]

A faulty userspace that calls destroy_session() before destroying the
connections can trigger the failure.  This patch prevents the issue by
refusing to destroy the session if there are outstanding connections.

------------[ cut here ]------------
kernel BUG at mm/slub.c:306!
invalid opcode: 0000 [OnePlusOSS#1] SMP PTI
CPU: 1 PID: 1224 Comm: iscsid Not tainted 5.4.0-rc2.iscsi+ OnePlusOSS#7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:__slab_free+0x181/0x350
[...]
[ 1209.686056] RSP: 0018:ffffa93d4074fae0 EFLAGS: 00010246
[ 1209.686694] RAX: ffff934efa5ad800 RBX: 000000008010000a RCX: ffff934efa5ad800
[ 1209.687651] RDX: ffff934efa5ad800 RSI: ffffeb4041e96b00 RDI: ffff934efd402c40
[ 1209.688582] RBP: ffffa93d4074fb80 R08: 0000000000000001 R09: ffffffffbb5dfa26
[ 1209.689425] R10: ffff934efa5ad800 R11: 0000000000000001 R12: ffffeb4041e96b00
[ 1209.690285] R13: ffff934efa5ad800 R14: ffff934efd402c40 R15: 0000000000000000
[ 1209.691213] FS:  00007f7945dfb540(0000) GS:ffff934efda80000(0000) knlGS:0000000000000000
[ 1209.692316] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1209.693013] CR2: 000055877fd3da80 CR3: 0000000077384000 CR4: 00000000000006e0
[ 1209.693897] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1209.694773] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1209.695631] Call Trace:
[ 1209.695957]  ? __wake_up_common_lock+0x8a/0xc0
[ 1209.696712]  iscsi_pool_free+0x26/0x40
[ 1209.697263]  iscsi_session_teardown+0x2f/0xf0
[ 1209.698117]  iscsi_sw_tcp_session_destroy+0x45/0x60
[ 1209.698831]  iscsi_if_rx+0xd88/0x14e0
[ 1209.699370]  netlink_unicast+0x16f/0x200
[ 1209.699932]  netlink_sendmsg+0x21a/0x3e0
[ 1209.700446]  sock_sendmsg+0x4f/0x60
[ 1209.700902]  ___sys_sendmsg+0x2ae/0x320
[ 1209.701451]  ? cp_new_stat+0x150/0x180
[ 1209.701922]  __sys_sendmsg+0x59/0xa0
[ 1209.702357]  do_syscall_64+0x52/0x160
[ 1209.702812]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1209.703419] RIP: 0033:0x7f7946433914
[...]
[ 1209.706084] RSP: 002b:00007fffb99f2378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1209.706994] RAX: ffffffffffffffda RBX: 000055bc869eac20 RCX: 00007f7946433914
[ 1209.708082] RDX: 0000000000000000 RSI: 00007fffb99f2390 RDI: 0000000000000005
[ 1209.709120] RBP: 00007fffb99f2390 R08: 000055bc84fe9320 R09: 00007fffb99f1f07
[ 1209.710110] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000038
[ 1209.711085] R13: 000055bc8502306e R14: 0000000000000000 R15: 0000000000000000
 Modules linked in:
 ---[ end trace a2d933ede7f730d8 ]---

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Nick Black <[email protected]>
Co-developed-by: Salman Qazi <[email protected]>
Signed-off-by: Salman Qazi <[email protected]>
Co-developed-by: Junho Ryu <[email protected]>
Signed-off-by: Junho Ryu <[email protected]>
Co-developed-by: Khazhismel Kumykov <[email protected]>
Signed-off-by: Khazhismel Kumykov <[email protected]>
Co-developed-by: Gabriel Krisman Bertazi <[email protected]>
Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
Reviewed-by: Lee Duncan <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I6906a6593a01ddd315ff744843b61f9d50739697
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request May 2, 2020
commit 28936b62e71e41600bab319f262ea9f9b1027629 upstream.

inode->i_blocks could be accessed concurrently as noticed by KCSAN,

 BUG: KCSAN: data-race in ext4_do_update_inode [ext4] / inode_add_bytes

 write to 0xffff9a00d4b982d0 of 8 bytes by task 22100 on cpu 118:
  inode_add_bytes+0x65/0xf0
  __inode_add_bytes at fs/stat.c:689
  (inlined by) inode_add_bytes at fs/stat.c:702
  ext4_mb_new_blocks+0x418/0xca0 [ext4]
  ext4_ext_map_blocks+0x1a6b/0x27b0 [ext4]
  ext4_map_blocks+0x1a9/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block_unwritten+0x33/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  ext4_da_write_begin+0x35f/0x8f0 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffff9a00d4b982d0 of 8 bytes by task 8 on cpu 65:
  ext4_do_update_inode+0x4a0/0xf60 [ext4]
  ext4_inode_blocks_set at fs/ext4/inode.c:4815
  ext4_mark_iloc_dirty+0xaf/0x160 [ext4]
  ext4_mark_inode_dirty+0x129/0x3e0 [ext4]
  ext4_convert_unwritten_extents+0x253/0x2d0 [ext4]
  ext4_convert_unwritten_io_end_vec+0xc5/0x150 [ext4]
  ext4_end_io_rsv_work+0x22c/0x350 [ext4]
  process_one_work+0x54f/0xb90
  worker_thread+0x80/0x5f0
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 4 locks held by kworker/u256:0/8:
  #0: ffff9a025abc4328 ((wq_completion)ext4-rsv-conversion){+.+.}, at: process_one_work+0x443/0xb90
  OnePlusOSS#1: ffffab5a862dbe20 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}, at: process_one_work+0x443/0xb90
  OnePlusOSS#2: ffff9a025a9d0f58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  OnePlusOSS#3: ffff9a00d4b985d8 (&(&ei->i_raw_lock)->rlock){+.+.}, at: ext4_do_update_inode+0xaa/0xf60 [ext4]
 irq event stamp: 3009267
 hardirqs last  enabled at (3009267): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (3009266): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (3009230): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (3009223): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 65 PID: 8 Comm: kworker/u256:0 Tainted: G L 5.6.0-rc2-next-20200221+ OnePlusOSS#7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work [ext4]

The plain read is outside of inode->i_lock critical section which
results in a data race. Fix it by adding READ_ONCE() there.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Qian Cai <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: Iae2d68b7f2e5317c8b256a7e4fbc22fdcdf0a8a4
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Jun 3, 2020
[ Upstream commit 76e752701a8af4404bbd9c45723f7cbd6e4a251e ]

Some servers seem to accept connections while booting but never send
the SMBNegotiate response neither close the connection, causing all
processes accessing the share hang on uninterruptible sleep state.

This happens when the cifs_demultiplex_thread detects the server is
unresponsive so releases the socket and start trying to reconnect.
At some point, the faulty server will accept the socket and the TCP
status will be set to NeedNegotiate. The first issued command accessing
the share will start the negotiation (pid 5828 below), but the response
will never arrive so other commands will be blocked waiting on the mutex
(pid 55352).

This patch checks for unresponsive servers also on the negotiate stage
releasing the socket and reconnecting if the response is not received
and checking again the tcp state when the mutex is acquired.

PID: 55352  TASK: ffff880fd6cc02c0  CPU: 0   COMMAND: "ls"
 #0 [ffff880fd9add9f0] schedule at ffffffff81467eb9
 OnePlusOSS#1 [ffff880fd9addb38] __mutex_lock_slowpath at ffffffff81468fe0
 OnePlusOSS#2 [ffff880fd9addba8] mutex_lock at ffffffff81468b1a
 OnePlusOSS#3 [ffff880fd9addbc0] cifs_reconnect_tcon at ffffffffa042f905 [cifs]
 OnePlusOSS#4 [ffff880fd9addc60] smb_init at ffffffffa042faeb [cifs]
 OnePlusOSS#5 [ffff880fd9addca0] CIFSSMBQPathInfo at ffffffffa04360b5 [cifs]
 ....

Which is waiting a mutex owned by:

PID: 5828   TASK: ffff880fcc55e400  CPU: 0   COMMAND: "xxxx"
 #0 [ffff880fbfdc19b8] schedule at ffffffff81467eb9
 OnePlusOSS#1 [ffff880fbfdc1b00] wait_for_response at ffffffffa044f96d [cifs]
 OnePlusOSS#2 [ffff880fbfdc1b60] SendReceive at ffffffffa04505ce [cifs]
 OnePlusOSS#3 [ffff880fbfdc1bb0] CIFSSMBNegotiate at ffffffffa0438d79 [cifs]
 OnePlusOSS#4 [ffff880fbfdc1c50] cifs_negotiate_protocol at ffffffffa043b383 [cifs]
 OnePlusOSS#5 [ffff880fbfdc1c80] cifs_reconnect_tcon at ffffffffa042f911 [cifs]
 OnePlusOSS#6 [ffff880fbfdc1d20] smb_init at ffffffffa042faeb [cifs]
 OnePlusOSS#7 [ffff880fbfdc1d60] CIFSSMBQFSInfo at ffffffffa0434eb0 [cifs]
 ....

Signed-off-by: Samuel Cabrero <[email protected]>
Reviewed-by: Aurélien Aptel <[email protected]>
Reviewed-by: Ronnie Sahlberg <[email protected]>
Signed-off-by: Steve French <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I588516ef6df5f4e7cb738f9cb602e59d94254a42
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Jun 14, 2020
[ Upstream commit ec9c7d19336ee98ecba8de80128aa405c45feebb ]

Exercising CPU hotplug on a 5.2 kernel with recent padata fixes from
cryptodev-2.6.git in an 8-CPU kvm guest...

    # modprobe tcrypt alg="pcrypt(rfc4106(gcm(aes)))" type=3
    # echo 0 > /sys/devices/system/cpu/cpu1/online
    # echo c > /sys/kernel/pcrypt/pencrypt/parallel_cpumask
    # modprobe tcrypt mode=215

...caused the following crash:

    BUG: kernel NULL pointer dereference, address: 0000000000000000
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 0 P4D 0
    Oops: 0000 [OnePlusOSS#1] SMP PTI
    CPU: 2 PID: 134 Comm: kworker/2:2 Not tainted 5.2.0-padata-base+ OnePlusOSS#7
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-<snip>
    Workqueue: pencrypt padata_parallel_worker
    RIP: 0010:padata_reorder+0xcb/0x180
    ...
    Call Trace:
     padata_do_serial+0x57/0x60
     pcrypt_aead_enc+0x3a/0x50 [pcrypt]
     padata_parallel_worker+0x9b/0xe0
     process_one_work+0x1b5/0x3f0
     worker_thread+0x4a/0x3c0
     ...

In padata_alloc_pd, pd->cpu is set using the user-supplied cpumask
instead of the effective cpumask, and in this case cpumask_first picked
an offline CPU.

The offline CPU's reorder->list.next is NULL in padata_reorder because
the list wasn't initialized in padata_init_pqueues, which only operates
on CPUs in the effective mask.

Fix by using the effective mask in padata_alloc_pd.

Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Signed-off-by: Daniel Jordan <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Steffen Klassert <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Herbert Xu <[email protected]>
Signed-off-by: Daniel Jordan <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: I768fd4ffb3de1ebcd3a71499eff1baec3607b431
ppajda pushed a commit to ppajda/android_kernel_oneplus_msm8996 that referenced this pull request Jul 4, 2020
commit 420902c9d086848a7548c83e0a49021514bd71b7 upstream.

If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can
deadlock our own worker - mount blocks kworker/3:2, sleeps forever more.

crash> ps|grep UN
    715      2   3  ffff880220734d30  UN   0.0       0      0  [kworker/3:2]
   9369   9341   2  ffff88021ffb7560  UN   1.3  493404 123184  Xorg
   9665   9664   3  ffff880225b92ab0  UN   0.0   47368    812  udisks-daemon
  10635  10403   3  ffff880222f22c70  UN   0.0   14904    936  mount
crash> bt ffff880220734d30
PID: 715    TASK: ffff880220734d30  CPU: 3   COMMAND: "kworker/3:2"
 #0 [ffff8802244c3c20] schedule at ffffffff8144584b
 OnePlusOSS#1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3
 OnePlusOSS#2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5
 OnePlusOSS#3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs]
 OnePlusOSS#4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs]
 OnePlusOSS#5 [ffff8802244c3e08] process_one_work at ffffffff81073726
 OnePlusOSS#6 [ffff8802244c3e68] worker_thread at ffffffff81073eba
 OnePlusOSS#7 [ffff8802244c3ec8] kthread at ffffffff810782e0
 OnePlusOSS#8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064
crash> rd ffff8802244c3cc8 10
ffff8802244c3cc8:  ffffffff814472b3 ffff880222f23250   .rD.....P2."....
ffff8802244c3cd8:  0000000000000000 0000000000000286   ................
ffff8802244c3ce8:  ffff8802244c3d30 ffff880220734d80   0=L$.....Ms ....
ffff8802244c3cf8:  ffff880222e8f628 0000000000000000   (.."............
ffff8802244c3d08:  0000000000000000 0000000000000002   ................
crash> struct rt_mutex ffff880222e8f628
struct rt_mutex {
  wait_lock = {
    raw_lock = {
      slock = 65537
    }
  },
  wait_list = {
    node_list = {
      next = 0xffff8802244c3d48,
      prev = 0xffff8802244c3d48
    }
  },
  owner = 0xffff880222f22c71,
  save_state = 0
}
crash> bt 0xffff880222f22c70
PID: 10635  TASK: ffff880222f22c70  CPU: 3   COMMAND: "mount"
 #0 [ffff8802216a9868] schedule at ffffffff8144584b
 OnePlusOSS#1 [ffff8802216a9910] schedule_timeout at ffffffff81446865
 OnePlusOSS#2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74
 OnePlusOSS#3 [ffff8802216a9a30] flush_work at ffffffff810712d3
 OnePlusOSS#4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463
 OnePlusOSS#5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba
 OnePlusOSS#6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632
 OnePlusOSS#7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c
 OnePlusOSS#8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs]
 OnePlusOSS#9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs]
    RIP: 00007f7b9303997a  RSP: 00007ffff443c7a8  RFLAGS: 00010202
    RAX: 00000000000000a5  RBX: ffffffff8144ef12  RCX: 00007f7b932e9ee0
    RDX: 00007f7b93d9a400  RSI: 00007f7b93d9a3e0  RDI: 00007f7b93d9a3c0
    RBP: 00007f7b93d9a2c0   R8: 00007f7b93d9a550   R9: 0000000000000001
    R10: ffffffffc0ed040e  R11: 0000000000000202  R12: 000000000000040e
    R13: 0000000000000000  R14: 00000000c0ed040e  R15: 00007ffff443ca20
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

Signed-off-by: Mike Galbraith <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
Acked-by: Mike Galbraith <[email protected]>
Signed-off-by: Jan Kara <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Change-Id: Ib963e18e5994a15e985b567c8b504ef91484e66d
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7 participants