Pull Ceph fixes from Sage Weil:
"There is a lifecycle fix in the auth code, a fix for a narrow race
condition on map, and a helpful message in the log when there is a
feature mismatch (which happens frequently now that the default
server-side options have changed)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
rbd: report unsupported features to syslog
rbd: fix rbd map vs notify races
libceph: make authorizer destruction independent of ceph_auth_client
Pull s390 fixes from Martin Schwidefsky:
"Three more bug fixes for 4.6
- Due to a race in the dynamic page table code a multi-threaded
program can cause a translation specification exception. With
panic_on_oops a user space program can crash the system.
- An information leak with the /dev/sclp device.
- A use after free in the s390 PCI code"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/sclp_ctl: fix potential information leak with /dev/sclp
s390/mm: fix asce_bits handling with dynamic pagetable levels
s390/pci: fix use after free in dma_init
A while ago, commit 9875201e10 ("rbd: fix use-after free of
rbd_dev->disk") fixed rbd unmap vs notify race by introducing
an exported wrapper for flushing notifies and sticking it into
do_rbd_remove().
A similar problem exists on the rbd map path, though: the watch is
registered in rbd_dev_image_probe(), while the disk is set up quite
a few steps later, in rbd_dev_device_setup(). Nothing prevents
a notify from coming in and crashing on a NULL rbd_dev->disk:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
Call Trace:
[<ffffffffa0508344>] rbd_watch_cb+0x34/0x180 [rbd]
[<ffffffffa04bd290>] do_event_work+0x40/0xb0 [libceph]
[<ffffffff8109d5db>] process_one_work+0x17b/0x470
[<ffffffff8109e3ab>] worker_thread+0x11b/0x400
[<ffffffff8109e290>] ? rescuer_thread+0x400/0x400
[<ffffffff810a5acf>] kthread+0xcf/0xe0
[<ffffffff810b41b3>] ? finish_task_switch+0x53/0x170
[<ffffffff810a5a00>] ? kthread_create_on_node+0x140/0x140
[<ffffffff81645dd8>] ret_from_fork+0x58/0x90
[<ffffffff810a5a00>] ? kthread_create_on_node+0x140/0x140
RIP [<ffffffffa050828a>] rbd_dev_refresh+0xfa/0x180 [rbd]
If an error occurs during rbd map, we have to error out, potentially
tearing down a watch. Just like on rbd unmap, notifies have to be
flushed, otherwise rbd_watch_cb() may end up trying to read in the
image header after rbd_dev_image_release() has run:
Assertion failure in rbd_dev_header_info() at line 4722:
rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
Call Trace:
[<ffffffff81cccee0>] ? rbd_parent_request_create+0x150/0x150
[<ffffffff81cd4e59>] rbd_dev_refresh+0x59/0x390
[<ffffffff81cd5229>] rbd_watch_cb+0x69/0x290
[<ffffffff81fde9bf>] do_event_work+0x10f/0x1c0
[<ffffffff81107799>] process_one_work+0x689/0x1a80
[<ffffffff811076f7>] ? process_one_work+0x5e7/0x1a80
[<ffffffff81132065>] ? finish_task_switch+0x225/0x640
[<ffffffff81107110>] ? pwq_dec_nr_in_flight+0x2b0/0x2b0
[<ffffffff81108c69>] worker_thread+0xd9/0x1320
[<ffffffff81108b90>] ? process_one_work+0x1a80/0x1a80
[<ffffffff8111b02d>] kthread+0x21d/0x2e0
[<ffffffff8111ae10>] ? kthread_stop+0x550/0x550
[<ffffffff82022802>] ret_from_fork+0x22/0x40
[<ffffffff8111ae10>] ? kthread_stop+0x550/0x550
RIP [<ffffffff81ccd8f9>] rbd_dev_header_info+0xa19/0x1e30
To fix this, a) check if RBD_DEV_FLAG_EXISTS is set before calling
revalidate_disk(), b) move ceph_osdc_flush_notifies() call into
rbd_dev_header_unwatch_sync() to cover rbd map error paths and c) turn
header read-in into a critical section. The latter also happens to
take care of rbd map foo@bar vs rbd snap rm foo@bar race.
Fixes: http://tracker.ceph.com/issues/15490
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Pull workqueue fix from Tejun Heo:
"So, it turns out we had a silly bug in the most fundamental part of
workqueue for a very long time. AFAICS, this dates back to pre-git
era and has quite likely been there from the time workqueue was first
introduced.
A work item uses its PENDING bit to synchronize multiple queuers.
Anyone who wins the PENDING bit owns the pending state of the work
item. Whether a queuer wins or loses the race, one thing should be
guaranteed - there will soon be at least one execution of the work
item - where "after" means that the execution instance would be able
to see all the changes that the queuer has made prior to the queueing
attempt.
Unfortunately, we were missing a smp_mb() after clearing PENDING for
execution, so nothing guaranteed visibility of the changes that a
queueing loser has made, which manifested as a reproducible blk-mq
stall.
Lots of kudos to Roman for debugging the problem. The patch for
-stable is the minimal one. For v3.7, Peter is working on a patch to
make the code path slightly more efficient and less fragile"
* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix ghost PENDING flag while doing MQ IO
Pull cgroup fixes from Tejun Heo:
"Two patches to fix a deadlock which can be easily triggered if memcg
charge moving is used.
This bug was introduced while converting threadgroup locking to a
global percpu_rwsem and is caused by cgroup controller task migration
path depending on the ability to create new kthreads. cpuset had a
similar issue which was fixed by performing heavy-lifting operations
asynchronous to task migration. The two patches fix the same issue in
memcg in a similar way. The first patch makes the mechanism generic
and the second relocates memcg charge moving outside the migration
path.
Given that we don't want to perform heavy operations while
writelocking threadgroup lock anyway, moving them out of the way is a
desirable solution. One thing to note is that the problem was
difficult to debug because lockdep couldn't figure out the deadlock
condition. Looking into how to improve that"
* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
memcg: relocate charge moving from ->attach to ->post_attach
cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback
Pull i2c fixes from Wolfram Sang:
"I2C has one buildfix, one ABBA deadlock fix, and three simple 'add ID'
patches"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: exynos5: Fix possible ABBA deadlock by keeping I2C clock prepared
i2c: cpm: Fix build break due to incompatible pointer types
i2c: ismt: Add Intel DNV PCI ID
i2c: xlp9xx: add support for Broadcom Vulcan
i2c: rk3x: add support for rk3228
Pull ARC fixes from Vineet Gupta:
- lockdep now works for ARCv2 builds
- enable DT reserved-memory binding (for forthcoming HDMI driver)
* tag 'arc-4.6-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: add support for reserved memory defined by device tree
ARC: support generic per-device coherent dma mem
Documentation: dt: arc: fix spelling mistakes
ARCv2: Enable LOCKDEP
Pull arch/nios2 fix from Ley Foon Tan:
"memset: use the right constraint modifier for the %4 output operand"
* tag 'nios2-v4.6-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
nios2: memset: use the right constraint modifier for the %4 output operand
Pull x86 platform driver fix from Darren Hart:
"Fix regression caused by hotkey enabling value in toshiba_acpi"
* tag 'platform-drivers-x86-v4.6-3' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86:
toshiba_acpi: Fix regression caused by hotkey enabling value
Depending on the size of the area to be memset'ed, the nios2 memset implementation
either uses a naive loop (for buffers smaller or equal than 8 bytes) or a more optimized
implementation (for buffers larger than 8 bytes). This implementation does 4-byte stores
rather than 1-byte stores to speed up memset.
However, we discovered that on our nios2 platform, memset() was not properly setting the
buffer to the expected value. A memset of 0xff would not set the entire buffer to 0xff, but to:
0xff 0x00 0xff 0x00 0xff 0x00 0xff 0x00 ...
Which is obviously incorrect. Our investigation has revealed that the problem lies in the
incorrect constraints used in the inline assembly.
The following piece of assembly, from the nios2 memset implementation, is supposed to
create a 4-byte value that repeats 4 times the 1-byte pattern passed as memset argument:
/* fill8 %3, %5 (c & 0xff) */
" slli %4, %5, 8\n"
" or %4, %4, %5\n"
" slli %3, %4, 16\n"
" or %3, %3, %4\n"
However, depending on the compiler and optimization level, this code might be compiled as:
34: 280a923a slli r5,r5,8
38: 294ab03a or r5,r5,r5
3c: 2808943a slli r4,r5,16
40: 2148b03a or r4,r4,r5
This is wrong because r5 gets used both for %5 and %4, which leads to the final pattern
stored in r4 to be 0xff00ff00 rather than the expected 0xffffffff.
%4 is defined with the "=r" constraint, i.e as an output operand. However, as explained in
http://www.ethernut.de/en/documents/arm-inline-asm.html, this does not prevent gcc from
using the same register for an output operand (%4) and input operand (%5). By using the
constraint modifier '&', we indicate that the register should be used for output only. With this
change, we get the following assembly output:
34: 2810923a slli r8,r5,8
38: 4150b03a or r8,r8,r5
3c: 400e943a slli r7,r8,16
40: 3a0eb03a or r7,r7,r8
Which correctly produces the 0xffffffff pattern when 0xff is passed as the memset() pattern.
It is worth mentioning the observed consequence of this bug: we were hitting the kernel
BUG() in mm/bootmem.c:__free() that verifies when marking a page as free that it was
previously marked as occupied (i.e that the bit was set to 1). The entire bootmem bitmap is
set to 0xff bit via a memset() during the bootmem initialization. The bootmem_free() call right
after the initialization was finding some bits to be set to 0, which didn't make sense since the
bitmap has just been memset'ed to 0xff. Except that due to the bug explained above, the
bitmap was in fact initialized to 0xff00ff00.
Thanks to Marek Vasut for his help and feedback.
Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Ley Foon Tan <lftan@altera.com>
The sclp_ctl_ioctl_sccb function uses two copy_from_user calls to
retrieve the sclp request from user space. The first copy_from_user
fetches the length of the request which is stored in the first two
bytes of the request. The second copy_from_user gets the complete
sclp request, but this copies the length field a second time.
A malicious user may have changed the length in the meantime.
Reported-by: Pengfei Wang <wpengfeinudt@gmail.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull networking fixes from David Miller:
1) Handle v4/v6 mixed sockets properly in soreuseport, from Craig
Gallak.
2) Bug fixes for the new macsec facility (missing kmalloc NULL checks,
missing locking around netdev list traversal, etc.) from Sabrina
Dubroca.
3) Fix handling of host routes on ifdown in ipv6, from David Ahern.
4) Fix double-fdput in bpf verifier. From Jann Horn.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (31 commits)
bpf: fix double-fdput in replace_map_fd_with_map_ptr()
net: ipv6: Delete host routes on an ifdown
Revert "ipv6: Revert optional address flusing on ifdown."
net/mlx4_en: fix spurious timestamping callbacks
net: dummy: remove note about being Y by default
cxgbi: fix uninitialized flowi6
ipv6: Revert optional address flusing on ifdown.
ipv4/fib: don't warn when primary address is missing if in_dev is dead
net/mlx5: Add pci shutdown callback
net/mlx5_core: Remove static from local variable
net/mlx5e: Use vport MTU rather than physical port MTU
net/mlx5e: Fix minimum MTU
net/mlx5e: Device's mtu field is u16 and not int
net/mlx5_core: Add ConnectX-5 to list of supported devices
net/mlx5e: Fix MLX5E_100BASE_T define
net/mlx5_core: Fix soft lockup in steering error flow
qlcnic: Update version to 5.3.64
net: stmmac: socfpga: Remove re-registration of reset controller
macsec: fix netlink attribute validation
macsec: add missing macsec prefix in uapi
...
Pull ARM SoC fixes from Arnd Bergmann:
"Here are the latest bug fixes for ARM SoCs, mostly addressing recent
regressions. Changes are across several platforms, so I'm listing
every change separately here.
Regressions since 4.5:
- A correction of the psci firmware DT binding, to prevent users from
relying on unintended semantics
- Actually getting the newly merged clock driver for some OMAP
platforms to work
- A revert of patches for the Qualcomm BAM, these need to be reworked
for 4.7 to avoid breaking boards other than the one they were
intended for
- A correction for the I2C device nodes on the Socionext Uniphier
platform
- i.MX SDHCI was broken for non-DT platforms due to a change with the
setting of the DMA mask
- A revert of a patch that accidentally added a nonexisting clock on
the Rensas "Porter" board
- A couple of OMAP fixes that are all related to suspend after the
power domain changes for dra7
- On Mediatek, revert part of the power domain initialization changes
that broke mt8173-evb
Fixes for older bugs:
- Workaround for an "external abort" in the omap34xx suspend/resume
code.
- The USB1/eSATA should not be listed as an excon device on
am57xx-beagle-x15 (broken since v4.0)
- A v4.5 regression in the TI AM33xx and AM43XX DT specifying
incorrect DMA request lines for the GPMC
- The jiffies calibration on Renesas platforms was incorrect for some
modern CPU cores.
- A hardware errata woraround for clockdomains on TI DRA7"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
drivers: firmware: psci: unify enable-method binding on ARM {64,32}-bit systems
arm64: dts: uniphier: fix I2C nodes of PH1-LD20
ARM: shmobile: timer: Fix preset_lpj leading to too short delays
Revert "ARM: dts: porter: Enable SCIF_CLK frequency and pins"
ARM: dts: r8a7791: Don't disable referenced optional clocks
Revert "ARM: OMAP: Catch callers of revision information prior to it being populated"
ARM: OMAP3: Fix external abort on 36xx waking from off mode idle
ARM: dts: am57xx-beagle-x15: remove extcon_usb1
ARM: dts: am437x: Fix GPMC dma properties
ARM: dts: am33xx: Fix GPMC dma properties
Revert "soc: mediatek: SCPSYS: Fix double enabling of regulators"
ARM: mach-imx: sdhci-esdhc-imx: initialize DMA mask
ARM: DRA7: clockdomain: Implement timer workaround for errata i874
ARM: OMAP: Catch callers of revision information prior to it being populated
ARM: dts: dra7: Correct clock tree for sys_32k_ck
ARM: OMAP: DRA7: Provide proper class to omap2_set_globals_tap
ARM: OMAP: DRA7: wakeupgen: Skip SAR save for wakeupgen
Revert "dts: msm8974: Add dma channels for blsp2_i2c1 node"
Revert "dts: msm8974: Add blsp2_bam dma node"
ARM: dts: Add clocks for dm814x ADPLL
This is more prep-work for the upcoming pty changes. Still just code
cleanup with no actual semantic changes.
This removes a bunch pointless complexity by just having the slave pty
side remember the dentry associated with the devpts slave rather than
the inode. That allows us to remove all the "look up the dentry" code
for when we want to remove it again.
Together with moving the tty pointer from "inode->i_private" to
"dentry->d_fsdata" and getting rid of pointless inode locking, this
removes about 30 lines of code. Not only is the end result smaller,
it's simpler and easier to understand.
The old code, for example, depended on the d_find_alias() to not just
find the dentry, but also to check that it is still hashed, which in
turn validated the tty pointer in the inode.
That is a _very_ roundabout way to say "invalidate the cached tty
pointer when the dentry is removed".
The new code just does
dentry->d_fsdata = NULL;
in devpts_pty_kill() instead, invalidating the tty pointer rather more
directly and obviously. Don't do something complex and subtle when the
obvious straightforward approach will do.
The rest of the patch (ie apart from code deletion and the above tty
pointer clearing) is just switching the calling convention to pass the
dentry or file pointer around instead of the inode.
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Jann Horn <jann@thejh.net>
Cc: Greg KH <greg@kroah.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When bpf(BPF_PROG_LOAD, ...) was invoked with a BPF program whose bytecode
references a non-map file descriptor as a map file descriptor, the error
handling code called fdput() twice instead of once (in __bpf_map_get() and
in replace_map_fd_with_map_ptr()). If the file descriptor table of the
current task is shared, this causes f_count to be decremented too much,
allowing the struct file to be freed while it is still in use
(use-after-free). This can be exploited to gain root privileges by an
unprivileged user.
This bug was introduced in
commit 0246e64d9a ("bpf: handle pseudo BPF_LD_IMM64 insn"), but is only
exploitable since
commit 1be7f75d16 ("bpf: enable non-root eBPF programs") because
previously, CAP_SYS_ADMIN was required to reach the vulnerable code.
(posted publicly according to request by maintainer)
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
It was a simple idea -- save IPv6 configured addresses on a link down
so that IPv6 behaves similar to IPv4. As always the devil is in the
details and the IPv6 stack as too many behavioral differences from IPv4
making the simple idea more complicated than it needs to be.
The current implementation for keeping IPv6 addresses can panic or spit
out a warning in one of many paths:
1. IPv6 route gets an IPv4 route as its 'next' which causes a panic in
rt6_fill_node while handling a route dump request.
2. rt->dst.obsolete is set to DST_OBSOLETE_DEAD hitting the WARN_ON in
fib6_del
3. Panic in fib6_purge_rt because rt6i_ref count is not 1.
The root cause of all these is references related to the host route for
an address that is retained.
So, this patch deletes the host route every time the ifdown loop runs.
Since the host route is deleted and will be re-generated an up there is
no longer a need for the l3mdev fix up. On the 'admin up' side move
addrconf_permanent_addr into the NETDEV_UP event handling so that it
runs only once versus on UP and CHANGE events.
All of the current panics and warnings appear to be related to
addresses on the loopback device, but given the catastrophic nature when
a bug is triggered this patch takes the conservative approach and evicts
all host routes rather than trying to determine when it can be re-used
and when it can not. That can be a later optimizaton if desired.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 841645b5f2.
Ok, this puts the feature back. I've decided to apply David A.'s
bug fix and run with that rather than make everyone wait another
whole release for this feature.
Signed-off-by: David S. Miller <davem@davemloft.net>
The bug in a workqueue leads to a stalled IO request in MQ ctx->rq_list
with the following backtrace:
[ 601.347452] INFO: task kworker/u129:5:1636 blocked for more than 120 seconds.
[ 601.347574] Tainted: G O 4.4.5-1-storage+ #6
[ 601.347651] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 601.348142] kworker/u129:5 D ffff880803077988 0 1636 2 0x00000000
[ 601.348519] Workqueue: ibnbd_server_fileio_wq ibnbd_dev_file_submit_io_worker [ibnbd_server]
[ 601.348999] ffff880803077988 ffff88080466b900 ffff8808033f9c80 ffff880803078000
[ 601.349662] ffff880807c95000 7fffffffffffffff ffffffff815b0920 ffff880803077ad0
[ 601.350333] ffff8808030779a0 ffffffff815b01d5 0000000000000000 ffff880803077a38
[ 601.350965] Call Trace:
[ 601.351203] [<ffffffff815b0920>] ? bit_wait+0x60/0x60
[ 601.351444] [<ffffffff815b01d5>] schedule+0x35/0x80
[ 601.351709] [<ffffffff815b2dd2>] schedule_timeout+0x192/0x230
[ 601.351958] [<ffffffff812d43f7>] ? blk_flush_plug_list+0xc7/0x220
[ 601.352208] [<ffffffff810bd737>] ? ktime_get+0x37/0xa0
[ 601.352446] [<ffffffff815b0920>] ? bit_wait+0x60/0x60
[ 601.352688] [<ffffffff815af784>] io_schedule_timeout+0xa4/0x110
[ 601.352951] [<ffffffff815b3a4e>] ? _raw_spin_unlock_irqrestore+0xe/0x10
[ 601.353196] [<ffffffff815b093b>] bit_wait_io+0x1b/0x70
[ 601.353440] [<ffffffff815b056d>] __wait_on_bit+0x5d/0x90
[ 601.353689] [<ffffffff81127bd0>] wait_on_page_bit+0xc0/0xd0
[ 601.353958] [<ffffffff81096db0>] ? autoremove_wake_function+0x40/0x40
[ 601.354200] [<ffffffff81127cc4>] __filemap_fdatawait_range+0xe4/0x140
[ 601.354441] [<ffffffff81127d34>] filemap_fdatawait_range+0x14/0x30
[ 601.354688] [<ffffffff81129a9f>] filemap_write_and_wait_range+0x3f/0x70
[ 601.354932] [<ffffffff811ced3b>] blkdev_fsync+0x1b/0x50
[ 601.355193] [<ffffffff811c82d9>] vfs_fsync_range+0x49/0xa0
[ 601.355432] [<ffffffff811cf45a>] blkdev_write_iter+0xca/0x100
[ 601.355679] [<ffffffff81197b1a>] __vfs_write+0xaa/0xe0
[ 601.355925] [<ffffffff81198379>] vfs_write+0xa9/0x1a0
[ 601.356164] [<ffffffff811c59d8>] kernel_write+0x38/0x50
The underlying device is a null_blk, with default parameters:
queue_mode = MQ
submit_queues = 1
Verification that nullb0 has something inflight:
root@pserver8:~# cat /sys/block/nullb0/inflight
0 1
root@pserver8:~# find /sys/block/nullb0/mq/0/cpu* -name rq_list -print -exec cat {} \;
...
/sys/block/nullb0/mq/0/cpu2/rq_list
CTX pending:
ffff8838038e2400
...
During debug it became clear that stalled request is always inserted in
the rq_list from the following path:
save_stack_trace_tsk + 34
blk_mq_insert_requests + 231
blk_mq_flush_plug_list + 281
blk_flush_plug_list + 199
wait_on_page_bit + 192
__filemap_fdatawait_range + 228
filemap_fdatawait_range + 20
filemap_write_and_wait_range + 63
blkdev_fsync + 27
vfs_fsync_range + 73
blkdev_write_iter + 202
__vfs_write + 170
vfs_write + 169
kernel_write + 56
So blk_flush_plug_list() was called with from_schedule == true.
If from_schedule is true, that means that finally blk_mq_insert_requests()
offloads execution of __blk_mq_run_hw_queue() and uses kblockd workqueue,
i.e. it calls kblockd_schedule_delayed_work_on().
That means, that we race with another CPU, which is about to execute
__blk_mq_run_hw_queue() work.
Further debugging shows the following traces from different CPUs:
CPU#0 CPU#1
---------------------------------- -------------------------------
reqeust A inserted
STORE hctx->ctx_map[0] bit marked
kblockd_schedule...() returns 1
<schedule to kblockd workqueue>
request B inserted
STORE hctx->ctx_map[1] bit marked
kblockd_schedule...() returns 0
*** WORK PENDING bit is cleared ***
flush_busy_ctxs() is executed, but
bit 1, set by CPU#1, is not observed
As a result request B pended forever.
This behaviour can be explained by speculative LOAD of hctx->ctx_map on
CPU#0, which is reordered with clear of PENDING bit and executed _before_
actual STORE of bit 1 on CPU#1.
The proper fix is an explicit full barrier <mfence>, which guarantees
that clear of PENDING bit is to be executed before all possible
speculative LOADS or STORES inside actual work function.
Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Michael Wang <yun.wang@profitbricks.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently ARM CPUs DT bindings allows different enable-method value for
PSCI based systems. On ARM 64-bit this property is required and must be
"psci" while on ARM 32-bit systems this property is optional and must
be "arm,psci" if present.
However, "arm,psci" has always been the compatible string for the PSCI
node, and was never intended to be the enable-method. So this is a bug
in the binding and not a deliberate attempt at specifying 32-bit
differently.
This is problematic if 32-bit OS is run on 64-bit system which has
"psci" as enable-method rather than the expected "arm,psci".
So let's unify the value into "psci" and remove support for "arm,psci"
before it finds any users.
Reported-by: Soby Mathew <Soby.Mathew@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
When multiple skb are TX-completed in a row, we might incorrectly keep
a timestamp of a prior skb and cause extra work.
Fixes: ec693d4701 ("net/mlx4_en: Add HW timestamping (TS) support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip6_route_output looks into different fields in the passed flowi6 structure,
yet cxgbi passes garbage in nearly all those fields. Zero the structure out
first.
Fixes: fc8d0590d9 ("libcxgbi: Add ipv6 api to driver")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds
Ilya Dryomov
Alexey Brodkin
Romain Perier
Martin Schwidefsky
Jann Horn
David Ahern
David S. Miller
Roman Pen
Sudeep Holla
Eric Dumazet
Ivan Babrou
Jiri Benc