Kees Cook [Thu, 20 Feb 2020 06:23:04 +0000 (22:23 -0800)]
net: core: Distribute switch variables for initialization
Variables declared in a switch statement before any case statements
cannot be automatically initialized with compiler instrumentation (as
they are not part of any execution flow). With GCC's proposed automatic
stack variable initialization feature, this triggers a warning (and they
don't get initialized). Clang's automatic stack variable initialization
(via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also
doesn't initialize such variables[1]. Note that these warnings (or silent
skipping) happen before the dead-store elimination optimization phase,
so even when the automatic initializations are later elided in favor of
direct initializations, the warnings remain.
To avoid these problems, move such variables into the "case" where
they're used or lift them up into the main function body.
net/core/skbuff.c: In function ‘skb_checksum_setup_ip’:
net/core/skbuff.c:4809:7: warning: statement will never be executed [-Wswitch-unreachable]
4809 | int err;
| ^~~
Kees Cook [Thu, 20 Feb 2020 06:23:18 +0000 (22:23 -0800)]
x86/xen: Distribute switch variables for initialization
Variables declared in a switch statement before any case statements
cannot be automatically initialized with compiler instrumentation (as
they are not part of any execution flow). With GCC's proposed automatic
stack variable initialization feature, this triggers a warning (and they
don't get initialized). Clang's automatic stack variable initialization
(via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also
doesn't initialize such variables[1]. Note that these warnings (or silent
skipping) happen before the dead-store elimination optimization phase,
so even when the automatic initializations are later elided in favor of
direct initializations, the warnings remain.
To avoid these problems, move such variables into the "case" where
they're used or lift them up into the main function body.
arch/x86/xen/enlighten_pv.c: In function ‘xen_write_msr_safe’:
arch/x86/xen/enlighten_pv.c:904:12: warning: statement will never be executed [-Wswitch-unreachable]
904 | unsigned which;
| ^~~~~
Catalin Marinas [Wed, 19 Feb 2020 12:31:56 +0000 (12:31 +0000)]
mm: Avoid creating virtual address aliases in brk()/mmap()/mremap()
Currently the arm64 kernel ignores the top address byte passed to brk(),
mmap() and mremap(). When the user is not aware of the 56-bit address
limit or relies on the kernel to return an error, untagging such
pointers has the potential to create address aliases in user-space.
Passing a tagged address to munmap(), madvise() is permitted since the
tagged pointer is expected to be inside an existing mapping.
The current behaviour breaks the existing glibc malloc() implementation
which relies on brk() with an address beyond 56-bit to be rejected by
the kernel.
Remove untagging in the above functions by partially reverting commit ce18d171cb73 ("mm: untag user pointers in mmap/munmap/mremap/brk"). In
addition, update the arm64 tagged-address-abi.rst document accordingly.
Shijie Luo [Sat, 15 Feb 2020 08:02:06 +0000 (03:02 -0500)]
ext4: add cond_resched() to __ext4_find_entry()
We tested a soft lockup problem in linux 4.19 which could also
be found in linux 5.x.
When dir inode takes up a large number of blocks, and if the
directory is growing when we are searching, it's possible the
restart branch could be called many times, and the do while loop
could hold cpu a long time.
Qian Cai [Fri, 7 Feb 2020 14:29:11 +0000 (09:29 -0500)]
ext4: fix a data race in EXT4_I(inode)->i_disksize
EXT4_I(inode)->i_disksize could be accessed concurrently as noticed by
KCSAN,
BUG: KCSAN: data-race in ext4_write_end [ext4] / ext4_writepages [ext4]
write to 0xffff91c6713b00f8 of 8 bytes by task 49268 on cpu 127:
ext4_write_end+0x4e3/0x750 [ext4]
ext4_update_i_disksize at fs/ext4/ext4.h:3032
(inlined by) ext4_update_inode_size at fs/ext4/ext4.h:3046
(inlined by) ext4_write_end at fs/ext4/inode.c:1287
generic_perform_write+0x208/0x2a0
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+0x91/0xb47
entry_SYSCALL_64_after_hwframe+0x49/0xbe
read to 0xffff91c6713b00f8 of 8 bytes by task 24872 on cpu 37:
ext4_writepages+0x10ac/0x1d00 [ext4]
mpage_map_and_submit_extent at fs/ext4/inode.c:2468
(inlined by) ext4_writepages at fs/ext4/inode.c:2772
do_writepages+0x5e/0x130
__writeback_single_inode+0xeb/0xb20
writeback_sb_inodes+0x429/0x900
__writeback_inodes_wb+0xc4/0x150
wb_writeback+0x4bd/0x870
wb_workfn+0x6b4/0x960
process_one_work+0x54c/0xbe0
worker_thread+0x80/0x650
kthread+0x1e0/0x200
ret_from_fork+0x27/0x50
Reported by Kernel Concurrency Sanitizer on:
CPU: 37 PID: 24872 Comm: kworker/u261:2 Tainted: G W O L 5.5.0-next-20200204+ #5
Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
Workqueue: writeback wb_workfn (flush-7:0)
Since only the read is operating as lockless (outside of the
"i_data_sem"), load tearing could introduce a logic bug. Fix it by
adding READ_ONCE() for the read and WRITE_ONCE() for the write.
Problem is that reading an attribute takes the kernfs lock in the kernfs
code, then resource->lock in the driver. During an ACPI notification, the
opposite happens: The resource lock is taken first, followed by the kernfs
lock when sysfs attributes are removed and re-created. Presumably this is
now seen due to some locking related changes in kernfs after v5.4, but it
was likely always a problem.
Fix the problem by not blindly acquiring the lock in the notification
function. It is only needed to protect the various update functions.
However, those update functions are called anyway when sysfs attributes
are read. This means that we can just stop calling those functions from
the notifier, and the resource lock in the notifier function is no longer
needed.
That leaves two situations:
First, METER_NOTIFY_CONFIG removes and re-allocates capability strings.
While it did so under the resource lock, _displaying_ those strings was not
protected, creating a race condition. To solve this problem, selectively
protect both removal/creation and reporting of capability attributes with
the resource lock.
Second, removing and re-creating the attribute files is no longer protected
by the resource lock. That doesn't matter since access to each individual
attribute is protected by the kernfs lock. Userspace may get messed up if
attributes disappear and reappear under its nose, but that is not different
than today, and there is nothing we can do about it without major driver
restructuring.
Last but not least, when removing the driver, remove attribute functions
first, then release capability strings. This avoids yet another race
condition.
Linus Torvalds [Thu, 20 Feb 2020 01:22:10 +0000 (17:22 -0800)]
Merge tag 'linux-kselftest-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest fixes from Shuah Khan:
"Fixes to build failures and other test bugs"
* tag 'linux-kselftest-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: openat2: fix build error on newer glibc
selftests: use LDLIBS for libraries instead of LDFLAGS
selftests: fix too long argument
selftests: allow detection of build failures
Kernel selftests: tpm2: check for tpm support
selftests/ftrace: Have pid filter test use instance flag
selftests: fix spelling mistaked "chaigned" -> "chained"
Maxime Ripard [Mon, 10 Feb 2020 10:04:17 +0000 (11:04 +0100)]
dt-bindings: media: csi: Fix clocks description
Commit 1de243b07666 ("media: dt-bindings: media: sun4i-csi: Add compatible
for CSI1 on A10/A20") introduced support for the CSI1 controller on A10 and
A20 that unlike CSI0 doesn't have an ISP and therefore only have two
clocks, the bus and module clocks.
The clocks and clock-names properties have thus been modified to allow
either two or tree clocks. However, the current list has the ISP clock at
the second position, which means the bindings expects a list of either
bus and isp, or bus, isp and mod. The initial intent of the patch was
obviously to have bus and mod in the former case.
Let's fix the binding so that it validates properly.
Fixes: 1de243b07666 ("media: dt-bindings: media: sun4i-csi: Add compatible for CSI1 on A10/A20") Signed-off-by: Maxime Ripard <[email protected]> Signed-off-by: Rob Herring <[email protected]>
dt-bindings: net: mdio: remove compatible string from example
Remove vendor specific compatible string from example, otherwise DT YAML
schemas validation may trigger warnings specific to TI ti,davinci_mdio
and not to the generic MDIO example.
For example, the "bus_freq" is required for davinci_mdio, but not required for
generic mdio example. As result following warning will be produced:
mdio.example.dt.yaml: mdio@5c030000: 'bus_freq' is a required property
Thierry Reding [Tue, 14 Jan 2020 12:38:21 +0000 (13:38 +0100)]
dt-bindings: memory-controller: Update example for Tegra124 EMC
The example in the Tegra124 EMC device tree binding looks like an old
version that doesn't contain all the required fields. Update it with a
version from the current DTS files to fix the make dt_binding_check
target.
Dave Airlie [Thu, 20 Feb 2020 01:01:28 +0000 (11:01 +1000)]
Merge tag 'drm-msm-fixes-2020-02-16' of https://gitlab.freedesktop.org/drm/msm into drm-fixes
+ fix UBWC on GPU and display side for sc7180
+ fix DSI suspend/resume issue encountered on sc7180
+ fix some breakage on so called "linux-android" devices
(fallout from sc7180/a618 support, not seen earlier
due to bootloader/firmware differences)
+ couple other misc fixes
David S. Miller [Thu, 20 Feb 2020 00:38:16 +0000 (16:38 -0800)]
Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/net-queue
Jeff Kirsher says:
====================
Intel Wired LAN Driver Updates 2020-02-19
This series contains fixes to the ice driver.
Brett fixes an issue where if a user sets an odd [tx|rx]-usecs value
through ethtool, the request is denied because the hardware is set to
have an ITR with 2us granularity. Also fix an issue where the VF has
not been completely removed/reset after being unbound from the host
driver, so resolve this by waiting for the VF remove/reset process to
happen before checking if the VF is disabled.
Michal fixes an issue, where when the user changes flow control via
ethtool, the OS is told the link is going down when that may not be the
case. Before the fix, the only way to get out of this state was to take
the interface down and up again.
====================
Willem de Bruijn [Wed, 19 Feb 2020 19:16:32 +0000 (14:16 -0500)]
udp: rehash on disconnect
As of the below commit, udp sockets bound to a specific address can
coexist with one bound to the any addr for the same port.
The commit also phased out the use of socket hashing based only on
port (hslot), in favor of always hashing on {addr, port} (hslot2).
The change broke the following behavior with disconnect (AF_UNSPEC):
server binds to 0.0.0.0:1337
server connects to 127.0.0.1:80
server disconnects
client connects to 127.0.0.1:1337
client sends "hello"
server reads "hello" // times out, packet did not find sk
On connect the server acquires a specific source addr suitable for
routing to its destination. On disconnect it reverts to the any addr.
The connect call triggers a rehash to a different hslot2. On
disconnect, add the same to return to the original hslot2.
Skip this step if the socket is going to be unhashed completely.
Rohit Maheshwari [Wed, 19 Feb 2020 04:10:22 +0000 (09:40 +0530)]
net/tls: Fix to avoid gettig invalid tls record
Current code doesn't check if tcp sequence number is starting from (/after)
1st record's start sequnce number. It only checks if seq number is before
1st record's end sequnce number. This problem will always be a possibility
in re-transmit case. If a record which belongs to a requested seq number is
already deleted, tls_get_record will start looking into list and as per the
check it will look if seq number is before the end seq of 1st record, which
will always be true and will return 1st record always, it should in fact
return NULL.
As part of the fix, start looking each record only if the sequence number
lies in the list else return NULL.
There is one more check added, driver look for the start marker record to
handle tcp packets which are before the tls offload start sequence number,
hence return 1st record if the record is tls start marker and seq number is
before the 1st record's starting sequence number.
Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure") Signed-off-by: Rohit Maheshwari <[email protected]> Reviewed-by: Jakub Kicinski <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Yonghong Song [Wed, 19 Feb 2020 23:47:57 +0000 (15:47 -0800)]
bpf: Fix a potential deadlock with bpf_map_do_batch
Commit 057996380a42 ("bpf: Add batch ops to all htab bpf map")
added lookup_and_delete batch operation for hash table.
The current implementation has bpf_lru_push_free() inside
the bucket lock, which may cause a deadlock.
To fix the issue, for htab_lru_map_lookup_and_delete_batch() in CPU0,
let us do bpf_lru_push_free() out of the htab bucket lock. This can
avoid the above deadlock scenario.
Brian Vazquez [Tue, 18 Feb 2020 17:25:52 +0000 (09:25 -0800)]
bpf: Do not grab the bucket spinlock by default on htab batch ops
Grabbing the spinlock for every bucket even if it's empty, was causing
significant perfomance cost when traversing htab maps that have only a
few entries. This patch addresses the issue by checking first the
bucket_cnt, if the bucket has some entries then we go and grab the
spinlock and proceed with the batching.
Tested with a htab of size 50K and different value of populated entries.
> virsh attach-device domain_name pci_0000_af_0_0.xml
error: Failed to attach device from pci_0000_af_0_0.xml
error: Cannot set interface MAC/vlanid to 00:de:ad:00:11:01/0 for
ifname ens1f1 vf 0: Device or resource busy
This is failing because the VF has not been completely removed/reset
after being unbound (via the virsh command above) from the host iavf
driver and ice_set_vf_mac() checks if the VF is disabled before waiting
for the reset to finish.
Fix this by waiting for the VF remove/reset process to happen before
checking if the VF is disabled. Also, since many functions for VF
administration on the PF were more or less calling the same 3 functions
(ice_wait_on_vf_reset(), ice_is_vf_disabled(), and ice_check_vf_init())
move these into the helper function ice_check_vf_ready_for_cfg(). Then
call this function in any flow that attempts to configure/query a VF
from the PF.
Lastly, increase the maximum wait time in ice_wait_on_vf_reset() to
800ms, and modify/add the #define(s) that determine the wait time.
This was done for robustness because in rare/stress cases VF removal can
take a max of ~800ms and previously the wait was a max of ~300ms.
Remove code that tell the OS that link is going down when user
change flow control via ethtool. When link is up it isn't certain
that link goes down after 0x0605 aq command. If link doesn't go
down, OS thinks that link is down, but physical link is up. To
reset this state user have to take interface down and up.
If link goes down after 0x0605 command, FW send information
about that and after that driver tells the OS that the link goes
down. So this code in ethtool is unnecessary.
Brett Creeley [Thu, 13 Feb 2020 21:31:23 +0000 (13:31 -0800)]
ice: Don't reject odd values of usecs set by user
Currently if a user sets an odd [tx|rx]-usecs value through ethtool,
the request is denied because the hardware is set to have an ITR
granularity of 2us. This caused poor customer experience. Fix this by
aligning to a register allowed value, which results in rounding down.
Also, print a once per ring container type message to be clear about
our intentions.
Also, change the ITR_TO_REG define to be the bitwise and of the ITR
setting and the ICE_ITR_MASK. This makes the purpose of ITR_TO_REG more
obvious.
The PN544 driver checks the "enable" polarity during of driver's probe and
it's doing that by turning ON and OFF NFC with different polarities until
enabling succeeds. It takes some time for the hardware to power-down, and
thus, to deassert the IRQ that is raised by turning ON the hardware.
Since the delay after last power-down of the polarity-checking process is
missed in the code, the interrupt may trigger immediately after installing
the IRQ handler (right after the checking is done), which results in IRQ
handler trying to touch the disabled HW and ends with marking NFC as
'DEAD' during of the driver's probe:
pn544_hci_i2c 1-002a: NFC: nfc_en polarity : active high
pn544_hci_i2c 1-002a: NFC: invalid len byte
shdlc: llc_shdlc_recv_frame: NULL Frame -> link is dead
This patch fixes the occasional NFC initialization failure on Nexus 7
device.
added support for access to the free-running counter via 'perf -e
msr/irperf/', but when exercised, it always returns a 0 count:
BEFORE:
$ perf stat -e instructions,msr/irperf/ true
Performance counter stats for 'true':
624,833 instructions
0 msr/irperf/
Simply set its enable bit - HWCR bit 30 - to make it start counting.
Enablement is restricted to all machines advertising IRPERF capability,
except those susceptible to an erratum that makes the IRPERF return
bad values.
That erratum occurs in Family 17h models 00-1fh [1], but not in F17h
models 20h and above [2].
AFTER (on a family 17h model 31h machine):
$ perf stat -e instructions,msr/irperf/ true
Performance counter stats for 'true':
621,690 instructions
622,490 msr/irperf/
[1] Revision Guide for AMD Family 17h Models 00h-0Fh Processors
[2] Revision Guide for AMD Family 17h Models 30h-3Fh Processors
The revision guides are available from the bugzilla Link below.
Please pull and let me know if there is any problem.
For -stable v5.3
('net/mlx5: Fix sleep while atomic in mlx5_eswitch_get_vepa')
For -stable v5.4
('net/mlx5: DR, Fix matching on vport gvmi')
('net/mlx5e: Fix crash in recovery flow without devlink reporter')
For -stable v5.5
('net/mlx5e: Reset RQ doorbell counter before moving RQ state from RST to RDY')
('net/mlx5e: Don't clear the whole vf config when switching modes')
====================
Linus Torvalds [Wed, 19 Feb 2020 17:26:59 +0000 (09:26 -0800)]
Merge tag 'sound-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"The only largish change in this pull request is about the revert of
the recent max98090 and its relevant patches due to regressions.
Other than that, all small fixes for ALSA core (covering KCSAN fuzzer
warnings in ALSA sequencer and rawmidi), Intel SOF HD-audio fixes, AMD
ACP fixes, usual HD-audio quirks, and various ASoC fixes"
* tag 'sound-5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda: Use scnprintf() for printing texts for sysfs/procfs
ALSA: hda/realtek - Apply quirk for yet another MSI laptop
ASoC: sun8i-codec: Fix setting DAI data format
ALSA: hda/realtek - Apply quirk for MSI GP63, too
ASoC: amd: ACP needs to be powered off in BIOS.
ASoC: hdmi-codec: set plugged_cb to NULL when component removing
ASoC: dapm: remove snd_soc_dapm_put_enum_double_locked
ASoC: max98090: revert invalid fix for handling SHDN
ALSA: rawmidi: Avoid bit fields for state flags
ALSA: seq: Fix concurrent access to queue current tick/time
ALSA: seq: Avoid concurrent access to queue flags
ASoC: codec2codec: avoid invalid/double-free of pcm runtime
ASoC: amd: Buffer Size instead of MAX Buffer
ASoC: SOF: Intel: hda: move i915 init earlier
ASoC: SOF: Intel: hda: fix ordering bug in resume flow
ALSA: hda: do not override bus codec_mask in link_get()
ASoC: atmel: fix atmel_ssc_set_audio link failure
ASoC: fsl_sai: Fix exiting path on probing failure
Keith Busch [Wed, 19 Feb 2020 15:59:36 +0000 (00:59 +0900)]
nvme: Fix uninitialized-variable warning
gcc may detect a false positive on nvme using an unintialized variable
if setting features fails. Since this is not a fast path, explicitly
initialize this variable to suppress the warning.
H.J. Lu [Thu, 16 Jan 2020 20:46:51 +0000 (12:46 -0800)]
x86/boot/compressed: Don't declare __force_order in kaslr_64.c
GCC 10 changed the default to -fno-common, which leads to
LD arch/x86/boot/compressed/vmlinux
ld: arch/x86/boot/compressed/pgtable_64.o:(.bss+0x0): multiple definition of `__force_order'; \
arch/x86/boot/compressed/kaslr_64.o:(.bss+0x0): first defined here
make[2]: *** [arch/x86/boot/compressed/Makefile:119: arch/x86/boot/compressed/vmlinux] Error 1
Since __force_order is already provided in pgtable_64.c, there is no
need to declare __force_order in kaslr_64.c.
Alex Deucher [Tue, 18 Feb 2020 18:20:30 +0000 (13:20 -0500)]
drm/amdgpu/display: clean up hdcp workqueue handling
Use the existence of the workqueue itself to determine when to
enable HDCP features rather than sprinkling asic checks all over
the code. Also add a check for the existence of the hdcp
workqueue in the irq handling on the off chance we get and HPD
RX interrupt with the CP bit set. This avoids a crash if
the driver doesn't support HDCP for a particular asic.
Fixes: 96a3b32e67236f ("drm/amd/display: only enable HDCP for DCN+")
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=206519 Reviewed-by: Bhawanpreet Lakha <[email protected]> Signed-off-by: Alex Deucher <[email protected]>
changzhu [Fri, 14 Feb 2020 02:57:17 +0000 (10:57 +0800)]
drm/amdgpu: add is_raven_kicker judgement for raven1
The rlc version of raven_kicer_rlc is different from the legacy rlc
version of raven_rlc. So it needs to add a judgement function for
raven_kicer_rlc and avoid disable GFXOFF when loading raven_kicer_rlc.
Shyjumon N [Thu, 6 Feb 2020 20:17:25 +0000 (13:17 -0700)]
nvme/pci: Add sleep quirk for Samsung and Toshiba drives
The Samsung SSD SM981/PM981 and Toshiba SSD KBG40ZNT256G on the Lenovo
C640 platform experience runtime resume issues when the SSDs are kept in
sleep/suspend mode for long time.
This patch applies the 'Simple Suspend' quirk to these configurations.
With this patch, the issue had not been observed in a 1+ day test.
Will Deacon [Wed, 19 Feb 2020 10:19:13 +0000 (10:19 +0000)]
arm64: memory: Add missing brackets to untagged_addr() macro
Add brackets around the evaluation of the 'addr' parameter to the
untagged_addr() macro so that the cast to 'u64' applies to the result
of the expression.
Cc: <[email protected]> Fixes: 597399d0cb91 ("arm64: tags: Preserve tags for addresses translated via TTBR1") Reported-by: Linus Torvalds <[email protected]> Signed-off-by: Will Deacon <[email protected]>
Stephen Kitt [Fri, 14 Feb 2020 17:26:28 +0000 (18:26 +0100)]
s390: remove obsolete ieee_emulation_warnings
s390 math emulation was removed with commit 5a79859ae0f3 ("s390:
remove 31 bit support"), rendering ieee_emulation_warnings useless.
The code still built because it was protected by CONFIG_MATHEMU, which
was no longer selectable.
This patch removes the sysctl_ieee_emulation_warnings declaration and
the sysctl entry declaration.
Will Deacon [Tue, 18 Feb 2020 17:27:56 +0000 (17:27 +0000)]
iommu/arm-smmu: Restore naming of driver parameter prefix
Extending the Arm SMMU driver to allow for modular builds changed
KBUILD_MODNAME to be "arm_smmu_mod" so that a single module could be
built from the multiple existing object files without the need to rename
any source files.
This inadvertently changed the name of the driver parameters, which may
lead to runtime issues if bootloaders are relying on the old names for
correctness (e.g. "arm-smmu.disable_bypass=0").
Although MODULE_PARAM_PREFIX can be overridden to restore the old naming
for builtin parameters, only the new name is matched by modprobe and so
loading the driver as a module would cause parameters specified on the
kernel command line to be ignored. Instead, rename "arm_smmu_mod" to
"arm_smmu". Whilst it's a bit of a bodge, this allows us to create a
single module without renaming any files and makes use of the fact that
underscores and hyphens can be used interchangeably in parameter names.
Robin Murphy [Tue, 18 Feb 2020 18:12:41 +0000 (18:12 +0000)]
iommu/qcom: Fix bogus detach logic
Currently, the implementation of qcom_iommu_domain_free() is guaranteed
to do one of two things: WARN() and leak everything, or dereference NULL
and crash. That alone is terrible, but in fact the whole idea of trying
to track the liveness of a domain via the qcom_domain->iommu pointer as
a sanity check is full of fundamentally flawed assumptions. Make things
robust and actually functional by not trying to be quite so clever.
Erez Shitrit [Tue, 14 Jan 2020 07:27:27 +0000 (09:27 +0200)]
net/mlx5: DR, Handle reformat capability over sw-steering tables
On flow table creation, send the relevant flags according to what the FW
currently supports.
When FW doesn't support reformat option over SW-steering managed table,
the driver shouldn't pass this.
Paul Blakey [Tue, 31 Dec 2019 15:04:15 +0000 (17:04 +0200)]
net/mlx5: Fix lowest FDB pool size
The pool sizes represent the pool sizes in the fw. when we request
a pool size from fw, it will return the next possible group.
We track how many pools the fw has left and start requesting groups
from the big to the small.
When we start request 4k group, which doesn't exists in fw, fw
wants to allocate the next possible size, 64k, but will fail since
its exhausted. The correct smallest pool size in fw is 128 and not 4k.
Fixes: 39ac237ce009 ("net/mlx5: E-Switch, Refactor chains and priorities") Signed-off-by: Paul Blakey <[email protected]> Reviewed-by: Roi Dayan <[email protected]> Signed-off-by: Saeed Mahameed <[email protected]>
Dmytro Linkin [Wed, 12 Feb 2020 09:32:39 +0000 (11:32 +0200)]
net/mlx5e: Don't clear the whole vf config when switching modes
There is no need to reset all vf config (except link state) between
legacy and switchdev modes changes.
Also, set link state to AUTO, when legacy enabled.
Fixes: 3b83b6c2e024 ("net/mlx5e: Clear VF config when switching modes") Signed-off-by: Dmytro Linkin <[email protected]> Reviewed-by: Roi Dayan <[email protected]> Signed-off-by: Saeed Mahameed <[email protected]>
Aya Levin [Wed, 12 Feb 2020 13:17:25 +0000 (15:17 +0200)]
net/mlx5e: Fix crash in recovery flow without devlink reporter
When health reporters are not supported, recovery function is invoked
directly, not via devlink health reporters.
In this direct flow, the recover function input parameter was passed
incorrectly and is causing a kernel oops. This patch is fixing the input
parameter.
Following call trace is observed on rx error health reporting.
Aya Levin [Mon, 9 Dec 2019 12:08:18 +0000 (14:08 +0200)]
net/mlx5e: Reset RQ doorbell counter before moving RQ state from RST to RDY
Initialize RQ doorbell counters to zero prior to moving an RQ from RST
to RDY state. Per HW spec, when RQ is back to RDY state, the descriptor
ID on the completion is reset. The doorbell record must comply.
Huy Nguyen [Mon, 3 Feb 2020 22:32:18 +0000 (16:32 -0600)]
net/mlx5: Fix sleep while atomic in mlx5_eswitch_get_vepa
rtnl_bridge_getlink is protected by rcu lock, so mlx5_eswitch_get_vepa
cannot take mutex lock. Two possible issues can happen:
1. User at the same time change vepa mode via RTM_SETLINK command.
2. User at the same time change the switchdev mode via devlink netlink
interface.
Case 1 cannot happen because rtnl executes one message in order.
Case 2 can happen but we do not expect user to change the switchdev mode
when changing vepa. Even if a user does it, so he will read a value
which is no longer valid.
Fixes: 8da202b24913 ("net/mlx5: E-Switch, Add support for VEPA in legacy mode.") Signed-off-by: Huy Nguyen <[email protected]> Reviewed-by: Mark Bloch <[email protected]> Signed-off-by: Saeed Mahameed <[email protected]>
Pavel Begunkov [Tue, 18 Feb 2020 21:19:09 +0000 (00:19 +0300)]
io_uring: fix use-after-free by io_cleanup_req()
io_cleanup_req() should be called before req->io is freed, and so
shouldn't be after __io_free_req() -> __io_req_aux_free(). Also,
it will be ignored for in io_free_req_many(), which use
__io_req_aux_free().
1) Restrict hashlimit size to 1048576, from Cong Wang.
2) Check for offload flags from nf_flow_table_offload_setup(),
this fixes a crash in case the hardware offload is disabled.
From Florian Westphal.
3) Three preparation patches to extend the conntrack clash resolution,
from Florian.
4) Extend clash resolution to deal with DNS packets from the same flow
racing to set up the NAT configuration.
5) Small documentation fix in pipapo, from Stefano Brivio.
6) Remove misleading unlikely() from pipapo_refill(), also from Stefano.
7) Reduce hashlimit mutex scope, from Cong Wang. This patch is actually
triggering another problem, still under discussion, another patch to
fix this will follow up.
====================
Filipe Manana [Thu, 13 Feb 2020 12:29:50 +0000 (12:29 +0000)]
Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
In btrfs_wait_ordered_range() once we find an ordered extent that has
finished with an error we exit the loop and don't wait for any other
ordered extents that might be still in progress.
All the users of btrfs_wait_ordered_range() expect that there are no more
ordered extents in progress after that function returns. So past fixes
such like the ones from the two following commits:
ff612ba7849964 ("btrfs: fix panic during relocation after ENOSPC before
writeback happens")
28aeeac1dd3080 ("Btrfs: fix panic when starting bg cache writeout after
IO error")
don't work when there are multiple ordered extents in the range.
Fix that by making btrfs_wait_ordered_range() wait for all ordered extents
even after it finds one that had an error.
This happens if we fail to insert our reserved file extent. At this
point we've already converted our reservation from ->bytes_may_use to
->bytes_reserved. However once we break we will attempt to free
everything from [cur_offset, end] from ->bytes_may_use, but our extent
reservation will overlap part of this.
Fix this problem by adding ins.offset (our extent allocation size) to
cur_offset so we remove the actual remaining part from ->bytes_may_use.
I validated this fix using my inject-error.py script
Josef Bacik [Thu, 13 Feb 2020 15:47:30 +0000 (10:47 -0500)]
btrfs: handle logged extent failure properly
If we're allocating a logged extent we attempt to insert an extent
record for the file extent directly. We increase
space_info->bytes_reserved, because the extent entry addition will call
btrfs_update_block_group(), which will convert the ->bytes_reserved to
->bytes_used. However if we fail at any point while inserting the
extent entry we will bail and leave space on ->bytes_reserved, which
will trigger a WARN_ON() on umount. Fix this by pinning the space if we
fail to insert, which is what happens in every other failure case that
involves adding the extent entry.
Josef Bacik [Thu, 13 Feb 2020 15:47:29 +0000 (10:47 -0500)]
btrfs: do not check delayed items are empty for single transaction cleanup
btrfs_assert_delayed_root_empty() will check if the delayed root is
completely empty, but this is a filesystem-wide check. On cleanup we
may have allowed other transactions to begin, for whatever reason, and
thus the delayed root is not empty.
So remove this check from cleanup_one_transation(). This however can
stay in btrfs_cleanup_transaction(), because it checks only after all of
the transactions have been properly cleaned up, and thus is valid.
Josef Bacik [Thu, 13 Feb 2020 15:47:28 +0000 (10:47 -0500)]
btrfs: reset fs_root to NULL on error in open_ctree
While running my error injection script I hit a panic when we tried to
clean up the fs_root when freeing the fs_root. This is because
fs_info->fs_root == PTR_ERR(-EIO), which isn't great. Fix this by
setting fs_info->fs_root = NULL; if we fail to read the root.
Linus Torvalds [Tue, 18 Feb 2020 22:54:30 +0000 (14:54 -0800)]
Merge tag 'tpmdd-next-20200217' of git://git.infradead.org/users/jjs/linux-tpmdd
Pull tpm fixes from Jarkko Sakkinen:
"Two bug fixes"
* tag 'tpmdd-next-20200217' of git://git.infradead.org/users/jjs/linux-tpmdd:
tpm: Initialize crypto_id of allocated_banks to HASH_ALGO__LAST
tpm: Revert tpm_tis_spi_mod.ko to tpm_tis_spi.ko.
Linus Torvalds [Tue, 18 Feb 2020 18:12:58 +0000 (10:12 -0800)]
pipe: make sure to wake up everybody when the last reader/writer closes
Andrei Vagin reported that commit 0ddad21d3e99 ("pipe: use exclusive
waits when reading or writing") broke one of the CRIU tests. He even
has a trivial reproducer:
and the problem - once he points it out - is obvious. We use these nice
exclusive waits, but when the last writer goes away, it then needs to
wake up _every_ reader (and conversely, the last reader disappearing
needs to wake every writer, of course).
In fact, when going through this, we had several small oddities around
how to wake things. We did in fact wake every reader when we changed
the size of the pipe buffers. But that's entirely pointless, since that
just acts as a possible source of new space - no new data to read.
And when we change the size of the buffer, we don't need to wake all
writers even when we add space - that case acts just as if somebody made
space by reading, and any writer that finds itself not filling it up
entirely will wake the next one.
On the other hand, on the exit path, we tried to limit the wakeups with
the proper poll keys etc, which is entirely pointless, because at that
point we obviously need to wake up everybody. So don't do that: just
wake up everybody - but only do that if the counts changed to zero.
So fix those non-IO wakeups to be more proper: space change doesn't add
any new data, but it might make room for writers, so it wakes up a
writer. And the actual changes to reader/writer counts should wake up
everybody, since everybody is affected (ie readers will all see EOF if
the writers have gone away, and writers will all get EPIPE if all
readers have gone away).
Stefano Brivio [Fri, 14 Feb 2020 17:14:14 +0000 (18:14 +0100)]
netfilter: nft_set_pipapo: Don't abuse unlikely() in pipapo_refill()
I originally used unlikely() in the if (match_only) clause, which
we hit on the mapping table for the last field in a set, to ensure
we avoid branching to the rest of for loop body, which is executed
more frequently.
However, Pablo reports, this is confusing as it gives the impression
that this is not a common case, and it's actually not the intended
usage of unlikely().
I couldn't observe any statistical difference in matching rates on
x864_64 and aarch64 without it, so just drop it.
Reported-by: Pablo Neira Ayuso <[email protected]> Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges") Signed-off-by: Stefano Brivio <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]>
Stefano Brivio [Fri, 14 Feb 2020 17:14:13 +0000 (18:14 +0100)]
netfilter: nft_set_pipapo: Fix mapping table example in comments
In both insertion and lookup examples, the two element pointers
of rule mapping tables were swapped. Fix that.
Reported-by: Pablo Neira Ayuso <[email protected]> Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges") Signed-off-by: Stefano Brivio <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]>
Ahmed reported ouf-of-order issues bisected to commit ba27b4cdaaa6
("net: dev: introduce support for sch BYPASS for lockless qdisc").
I can't find any working solution other than a plain revert.
This will introduce some minor performance regressions for
pfifo_fast qdisc. I plan to address them in net-next with more
indirect call wrapper boilerplate for qdiscs.
Reported-by: Ahmad Fatoum <[email protected]> Fixes: ba27b4cdaaa6 ("net: dev: introduce support for sch BYPASS for lockless qdisc") Signed-off-by: Paolo Abeni <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Florian Westphal [Mon, 17 Feb 2020 15:54:38 +0000 (16:54 +0100)]
mptcp: fix bogus socket flag values
Dan Carpenter reports static checker warnings due to bogus BIT() usage:
net/mptcp/subflow.c:571 subflow_write_space() warn: test_bit() takes a bit number
net/mptcp/subflow.c:694 subflow_state_change() warn: test_bit() takes a bit number
net/mptcp/protocol.c:261 ssk_check_wmem() warn: test_bit() takes a bit number
[..]
This is harmless (we use bits 1 & 2 instead of 0 and 1), but would
break eventually when adding BIT(5) (or 6, depends on size of 'long').
Just use 0 and 1, the values are only passed to test/set/clear_bit
functions.
Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") Reported-by: Dan Carpenter <[email protected]> Signed-off-by: Florian Westphal <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Michal Kalderon [Mon, 17 Feb 2020 11:37:18 +0000 (13:37 +0200)]
qede: Fix race between rdma destroy workqueue and link change event
If an event is added while the rdma workqueue is being destroyed
it could lead to several races, list corruption, null pointer
dereference during queue_work or init_queue.
This fixes the race between the two flows which can occur during
shutdown.
A kref object and a completion object are added to the rdma_dev
structure, these are initialized before the workqueue is created.
The refcnt is used to indicate work is being added to the
workqueue and ensures the cleanup flow won't start while we're in
the middle of adding the event.
Once the work is added, the refcnt is decreased and the cleanup flow
is safe to run.
Merge tag 'thunderbolt-fix-for-v5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-linus
Mika writes:
thunderbolt: Fix for v5.6-rc3
Single fix that orders the THUNDERBOLT MAINTAINERS record according to
parse-maintainers.pl.
* tag 'thunderbolt-fix-for-v5.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
MAINTAINERS: Sort entries in database for THUNDERBOLT
Commit e0d5896bd356 ("arm64: lse: fix LSE atomics with LLVM's integrated
assembler") broke the build when clang is used in connjunction with the
binutils assembler ("-no-integrated-as"). This happens because
__LSE_PREAMBLE is defined as ".arch armv8-a+lse", which overrides the
version of the CPU architecture passed via the "-march" paramter to gas:
$ aarch64-none-linux-gnu-as -EL -I ./arch/arm64/include
-I ./arch/arm64/include/generated
-I ./include -I ./include
-I ./arch/arm64/include/uapi
-I ./arch/arm64/include/generated/uapi
-I ./include/uapi -I ./include/generated/uapi
-I ./init -I ./init
-march=armv8.3-a -o init/do_mounts.o
/tmp/do_mounts-d7992a.s
/tmp/do_mounts-d7992a.s: Assembler messages:
/tmp/do_mounts-d7992a.s:1959: Error: selected processor does not support `autiasp'
/tmp/do_mounts-d7992a.s:2021: Error: selected processor does not support `paciasp'
/tmp/do_mounts-d7992a.s:2157: Error: selected processor does not support `autiasp'
/tmp/do_mounts-d7992a.s:2175: Error: selected processor does not support `paciasp'
/tmp/do_mounts-d7992a.s:2494: Error: selected processor does not support `autiasp'
Fix the issue by replacing ".arch armv8-a+lse" with ".arch_extension lse".
Sami confirms that the clang integrated assembler does now support the
'.arch_extension' directive, so this change will be fine even for LTO
builds in future.
Joerg Roedel [Mon, 17 Feb 2020 16:29:55 +0000 (17:29 +0100)]
iommu/vt-d: Simplify check in identity_mapping()
The function only has one call-site and there it is never called with
dummy or deferred devices. Simplify the check in the function to
account for that.
Joerg Roedel [Mon, 17 Feb 2020 16:20:59 +0000 (17:20 +0100)]
iommu/vt-d: Do deferred attachment in iommu_need_mapping()
The attachment of deferred devices needs to happen before the check
whether the device is identity mapped or not. Otherwise the check will
return wrong results, cause warnings boot failures in kdump kernels, like
WARNING: CPU: 0 PID: 318 at ../drivers/iommu/intel-iommu.c:592 domain_get_iommu+0x61/0x70
libbpf: Sanitise internal map names so they are not rejected by the kernel
The kernel only accepts map names with alphanumeric characters, underscores
and periods in their name. However, the auto-generated internal map names
used by libbpf takes their prefix from the user-supplied BPF object name,
which has no such restriction. This can lead to "Invalid argument" errors
when trying to load a BPF program using global variables.
Fix this by sanitising the map names, replacing any non-allowed characters
with underscores.
bpf, uapi: Remove text about bpf_redirect_map() giving higher performance
The performance of bpf_redirect() is now roughly the same as that of
bpf_redirect_map(). However, David Ahern pointed out that the header file
has not been updated to reflect this, and still says that a significant
performance increase is possible when using bpf_redirect_map(). Remove this
text from the bpf_redirect_map() description, and reword the description in
bpf_redirect() slightly. Also fix the 'Return' section of the
bpf_redirect_map() documentation.
Tianjia Zhang [Mon, 10 Feb 2020 12:44:40 +0000 (20:44 +0800)]
ima: add sm3 algorithm to hash algorithm configuration list
sm3 has been supported by the ima hash algorithm, but it is not
yet in the Kconfig configuration list. After adding, both ima and tpm2
can support sm3 well.
Tianjia Zhang [Mon, 10 Feb 2020 12:44:39 +0000 (20:44 +0800)]
crypto: rename sm3-256 to sm3 in hash_algo_name
The name sm3-256 is defined in hash_algo_name in hash_info, but the
algorithm name implemented in sm3_generic.c is sm3, which will cause
the sm3-256 algorithm to be not found in some application scenarios of
the hash algorithm, and an ENOENT error will occur. For example,
IMA, keys, and other subsystems that reference hash_algo_name all use
the hash algorithm of sm3.
efi: Only print errors about failing to get certs if EFI vars are found
If CONFIG_LOAD_UEFI_KEYS is enabled, the kernel attempts to load the certs
from the db, dbx and MokListRT EFI variables into the appropriate keyrings.
But it just assumes that the variables will be present and prints an error
if the certs can't be loaded, even when is possible that the variables may
not exist. For example the MokListRT variable will only be present if shim
is used.
So only print an error message about failing to get the certs list from an
EFI variable if this is found. Otherwise these printed errors just pollute
the kernel log ring buffer with confusing messages like the following:
[ 5.427251] Couldn't get size: 0x800000000000000e
[ 5.427261] MODSIGN: Couldn't get UEFI db list
[ 5.428012] Couldn't get size: 0x800000000000000e
[ 5.428023] Couldn't get UEFI MokListRT
powerpc/xmon: Fix whitespace handling in getstring()
The ls (lookup symbol) and zr (reboot) commands use xmon's getstring()
helper to read a string argument from the xmon prompt. This function
skips over leading whitespace, but doesn't check if the first
"non-whitespace" character is a newline which causes some odd
behaviour (<enter> indicates a the enter key was pressed):
0:mon> ls<enter>
printk<enter>
Symbol '
printk' not found.
0:mon>
With commit 2d9b332d99b ("powerpc/xmon: Allow passing an argument to
ppc_md.restart()") we have a similar problem with the zr command.
Previously zr took no arguments so "zr<enter> would trigger a reboot.
With that patch applied a second newline needs to be sent in order for
the reboot to occur. Fix this by checking if the leading whitespace
ended on a newline:
Christophe Leroy [Fri, 14 Feb 2020 06:53:00 +0000 (06:53 +0000)]
powerpc/6xx: Fix power_save_ppc32_restore() with CONFIG_VMAP_STACK
power_save_ppc32_restore() is called during exception entry, before
re-enabling the MMU. It substracts KERNELBASE from the address
of nap_save_msscr0 to access it.
With CONFIG_VMAP_STACK enabled, data MMU translation has already been
re-enabled, so power_save_ppc32_restore() has to access
nap_save_msscr0 by its virtual address.
Christophe Leroy [Sat, 15 Feb 2020 10:14:25 +0000 (10:14 +0000)]
powerpc/32s: Fix DSI and ISI exceptions for CONFIG_VMAP_STACK
hash_page() needs to read page tables from kernel memory. When entire
kernel memory is mapped by BATs, which is normally the case when
CONFIG_STRICT_KERNEL_RWX is not set, it works even if the page hosting
the page table is not referenced in the MMU hash table.
However, if the page where the page table resides is not covered by
a BAT, a DSI fault can be encountered from hash_page(), and it loops
forever. This can happen when CONFIG_STRICT_KERNEL_RWX is selected
and the alignment of the different regions is too small to allow
covering the entire memory with BATs. This also happens when
CONFIG_DEBUG_PAGEALLOC is selected or when booting with 'nobats'
flag.
Also, if the page containing the kernel stack is not present in the
MMU hash table, registers cannot be saved and a recursive DSI fault
is encountered.
To allow hash_page() to properly do its job at all time and load the
MMU hash table whenever needed, it must run with data MMU disabled.
This means it must be called before re-enabling data MMU. To allow
this, registers clobbered by hash_page() and create_hpte() have to
be saved in the thread struct together with SRR0, SSR1, DAR and DSISR.
It is also necessary to ensure that DSI prolog doesn't overwrite
regs saved by prolog of the current running exception. That means:
- DSI can only use SPRN_SPRG_SCRATCH0
- Exceptions must free SPRN_SPRG_SCRATCH0 before writing to the stack.
This also fixes the Oops reported by Erhard when create_hpte() is
called by add_hash_page().
Due to prolog size increase, a few more exceptions had to get split
in two parts.
powerpc/tm: Fix clearing MSR[TS] in current when reclaiming on signal delivery
After a treclaim, we expect to be in non-transactional state. If we
don't clear the current thread's MSR[TS] before we get preempted, then
tm_recheckpoint_new_task() will recheckpoint and we get rescheduled in
suspended transaction state.
When handling a signal caught in transactional state,
handle_rt_signal64() calls get_tm_stackpointer() that treclaims the
transaction using tm_reclaim_current() but without clearing the
thread's MSR[TS]. This can cause the TM Bad Thing exception below if
later we pagefault and get preempted trying to access the user's
sigframe, using __put_user(). Afterwards, when we are rescheduled back
into do_page_fault() (but now in suspended state since the thread's
MSR[TS] was not cleared), upon executing 'rfid' after completion of
the page fault handling, the exception is raised because a transition
from suspended to non-transactional state is invalid.
The simplified sequence of events that triggers the above exception is:
... # userspace in NON-TRANSACTIONAL state
tbegin # userspace in TRANSACTIONAL state
signal delivery # kernelspace in SUSPENDED state
handle_rt_signal64()
get_tm_stackpointer()
treclaim # kernelspace in NON-TRANSACTIONAL state
__put_user()
page fault happens. We will never get back here because of the TM Bad Thing exception.
page fault handling kicks in and we voluntarily preempt ourselves
do_page_fault()
__schedule()
__switch_to(other_task)
our task is rescheduled and we recheckpoint because the thread's MSR[TS] was not cleared
__switch_to(our_task)
switch_to_tm()
tm_recheckpoint_new_task()
trechkpt # kernelspace in SUSPENDED state
The page fault handling resumes, but now we are in suspended transaction state
do_page_fault() completes
rfid <----- trying to get back where the page fault happened (we were non-transactional back then)
TM Bad Thing # illegal transition from suspended to non-transactional
This patch fixes that issue by clearing the current thread's MSR[TS]
just after treclaim in get_tm_stackpointer() so that we stay in
non-transactional state in case we are preempted. In order to make
treclaim and clearing the thread's MSR[TS] atomic from a preemption
perspective when CONFIG_PREEMPT is set, preempt_disable/enable() is
used. It's also necessary to save the previous value of the thread's
MSR before get_tm_stackpointer() is called so that it can be exposed
to the signal handler later in setup_tm_sigcontexts() to inform the
userspace MSR at the moment of the signal delivery.
Found with tm-signal-context-force-tm kernel selftest.
Takashi Iwai [Tue, 18 Feb 2020 09:14:09 +0000 (10:14 +0100)]
ALSA: hda: Use scnprintf() for printing texts for sysfs/procfs
Some code in HD-audio driver calls snprintf() in a loop and still
expects that the return value were actually written size, while
snprintf() returns the expected would-be length instead. When the
given buffer limit were small, this leads to a buffer overflow.
Use scnprintf() for addressing those issues. It returns the actually
written size unlike snprintf().
Chris Wilson [Tue, 11 Feb 2020 12:01:31 +0000 (12:01 +0000)]
drm/i915/gt: Avoid resetting ring->head outside of its timeline mutex
We manipulate ring->head while active in i915_request_retire underneath
the timeline manipulation. We cannot rely on a stable ring->head outside
of the timeline->mutex, in particular while setting up the context for
resume and reset.
Chris Wilson [Fri, 7 Feb 2020 21:14:52 +0000 (21:14 +0000)]
drm/i915/execlists: Always force a context reload when rewinding RING_TAIL
If we rewind the RING_TAIL on a context, due to a preemption event, we
must force the context restore for the RING_TAIL update to be properly
handled. Rather than note which preemption events may cause us to rewind
the tail, compare the new request's tail with the previously submitted
RING_TAIL, as it turns out that timeslicing was causing unexpected
rewinds.
<idle>-0 0d.s2 1280851190us : __execlists_submission_tasklet: 0000:00:02.0 rcs0: expired last=130:4698, prio=3, hint=3
<idle>-0 0d.s2 1280851192us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 66:119966, current 119964
<idle>-0 0d.s2 1280851195us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 130:4698, current 4695
<idle>-0 0d.s2 1280851198us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 130:4696, current 4695
^---- Note we unwind 2 requests from the same context
<idle>-0 0d.s2 1280851208us : __i915_request_submit: 0000:00:02.0 rcs0: fence 130:4696, current 4695
<idle>-0 0d.s2 1280851213us : __i915_request_submit: 0000:00:02.0 rcs0: fence 134:1508, current 1506
^---- But to apply the new timeslice, we have to replay the first request
before the new client can start -- the unexpected RING_TAIL rewind
page-flags: define PG_reserved behavior on compound pages
As far as I can see there's no users of PG_reserved on compound pages.
Let's use PF_NO_COMPOUND here.
drm_pci_alloc has been declared broken since it mixes GFP_COMP and
SetPageReserved. Avoid this conflict by weaning ourselves off using the
abstraction and using the dma functions directly.