We have some many cases that will create child process as well, such as
pidfd_wait. Previously, we will signal/kill the parent process when it
is time out, but this signal will not be sent to its child process. In
such case, if child process doesn't terminate itself, ksefltest framework
will hang forever.
Here we group all its child processes so that kill() can signal all of
them in timeout.
The timeout setting for the rtc kselftest is currently 90 seconds. This
setting is used by the kselftest runner to stop running a test if it
takes longer than the assigned value.
However, two of the test cases inside rtc set alarms. These alarms are
set to the next beginning of the minute, so each of these test cases may
take up to, in the worst case, 60 seconds.
In order to allow for all test cases in rtc to run, even in the worst
case, when using the kselftest runner, the timeout value should be
increased to at least 120. Set it to 180, so there's some additional
slack.
Correct operation can be tested by running the following command right
after the start of a minute (low second count), and checking that all
test cases run:
./run_kselftest.sh -c rtc
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The call sequence suggested that misc_device /dev file can be opened
before misc device is yet to be registered, which is done only once.
Here punit_misc_dev_lock was used as common lock, to protect the
registration by multiple ISST HW drivers, one time setup, prevent
duplicate registry of misc device and prevent load/unload when device
is open.
We can split into locks:
- One which just prevent duplicate call to misc_register() and one
time setup. Also never call again if the misc_register() failed or
required one time setup is failed. This lock is not shared with
any misc device callbacks.
- The other lock protects registry, load and unload of HW drivers.
Sequence in isst_if_cdev_register()
- Register callbacks under punit_misc_dev_open_lock
- Call isst_misc_reg() which registers misc_device on the first
registry which is under punit_misc_dev_reg_lock, which is not
shared with callbacks.
Sequence in isst_if_cdev_unregister
Just opposite of isst_if_cdev_register
Reported-and-tested-by: Liwei Song <liwei.song@windriver.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Link: https://lore.kernel.org/r/20220112022521.54669-1-srinivas.pandruvada@linux.intel.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Add touchscreen info for RWC NANOTE P8 (AY07J) 2-in-1.
Signed-off-by: Yuka Kawajiri <yukx00@gmail.com> Link: https://lore.kernel.org/r/20220111154019.4599-1-yukx00@gmail.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Currently if we get IO error while doing send then we abort without
logging information about which file caused issue. So log it to help
with debugging.
CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Dāvis Mosāns <davispuh@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's a followup to the previous commit f15309d7ad5d ("parisc: Add
ioread64_hi_lo() and iowrite64_hi_lo()") which does only half of
the job. Add the rest, so we won't get a new kernel test robot
reports.
Fixes: f15309d7ad5d ("parisc: Add ioread64_hi_lo() and iowrite64_hi_lo()") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When kernel boots with a NUMA topology with some NUMA nodes offline, the PCI
driver should only set an online NUMA node on the device. This can happen
during KDUMP where some NUMA nodes are not made online by the KDUMP kernel.
This patch also fixes the case where kernel is booting with "numa=off".
Fixes: 999dd956d838 ("PCI: hv: Add support for protocol 1.3 and support PCI_BUS_RELATIONS2") Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@microsoft.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Link: https://lore.kernel.org/r/1643247814-15184-1-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Oded Gabbay reports that enabling NUMA balancing causes corruption with
his Gaudi accelerator test load:
"All the details are in the bug, but the bottom line is that somehow,
this patch causes corruption when the numa balancing feature is
enabled AND we don't use process affinity AND we use GUP to pin pages
so our accelerator can DMA to/from system memory.
Either disabling numa balancing, using process affinity to bind to
specific numa-node or reverting this patch causes the bug to
disappear"
and Oded bisected the issue to commit 09854ba94c6a ("mm: do_wp_page()
simplification").
Now, the NUMA balancing shouldn't actually be changing the writability
of a page, and as such shouldn't matter for COW. But it appears it
does. Suspicious.
However, regardless of that, the condition for enabling NUMA faults in
change_pte_range() is nonsensical. It uses "page_mapcount(page)" to
decide if a COW page should be NUMA-protected or not, and that makes
absolutely no sense.
The number of mappings a page has is irrelevant: not only does GUP get a
reference to a page as in Oded's case, but the other mappings migth be
paged out and the only reference to them would be in the page count.
Since we should never try to NUMA-balance a page that we can't move
anyway due to other references, just fix the code to use 'page_count()'.
Oded confirms that that fixes his issue.
Now, this does imply that something in NUMA balancing ends up changing
page protections (other than the obvious one of making the page
inaccessible to get the NUMA faulting information). Otherwise the COW
simplification wouldn't matter - since doing the GUP on the page would
make sure it's writable.
The cause of that permission change would be good to figure out too,
since it clearly results in spurious COW events - but fixing the
nonsensical test that just happened to work before is obviously the
CorrectThing(tm) to do regardless.
On reads with MMC_READ_MULTIPLE_BLOCK that fail,
the recovery handler will use MMC_READ_SINGLE_BLOCK for
each of the blocks, up to MMC_READ_SINGLE_RETRIES times each.
The logic for this is fixed to never report unsuccessful reads
as success to the block layer.
On command error with retries remaining, blk_update_request was
called with whatever value error was set last to.
In case it was last set to BLK_STS_OK (default), the read will be
reported as success, even though there was no data read from the device.
This could happen on a CRC mismatch for the response,
a card rejecting the command (e.g. again due to a CRC mismatch).
In case it was last set to BLK_STS_IOERR, the error is reported correctly,
but no retries will be attempted.
The bug is caused by overrunning the sglist and incorrectly testing
sg_dma_len(sglist) before nents. Normally this doesn't cause a crash,
but in this case sglist crossed a page boundary. This occurs in the
following code:
while (sg_dma_len(sglist) && nents--) {
The fix is simply to test nents first and move the decrement of nents
into the loop.
Reported-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a build error when using a kernel .config file from
'kernel test robot' for a different build problem:
hppa64-linux-ld: drivers/tty/serial/8250/8250_gsc.o: in function `.LC3':
(.data.rel.ro+0x18): undefined reference to `iosapic_serial_irq'
when:
CONFIG_GSC=y
CONFIG_SERIO_GSCPS2=y
CONFIG_SERIAL_8250_GSC=y
CONFIG_PCI is not set
and hence PCI_LBA is not set.
IOSAPIC depends on PCI_LBA, so IOSAPIC is not set/enabled.
Make the use of iosapic_serial_irq() conditional to fix the build error.
Remove a WARN on an "AVIC IPI invalid target" exit, the WARN is trivial
to trigger from guest as it will fail on any destination APIC ID that
doesn't exist from the guest's perspective.
Don't bother recording anything in the kernel log, the common tracepoint
for kvm_avic_incomplete_ipi() is sufficient for debugging.
This patch adds support for the UGTABLET WP5540 digitizer tablet
devices. Without it, the pen moves the cursor, but neither the
buttons nor the tap sensor in the tip do work.
Contention for the mailbox interface may occur during driver initialization
(immediately after a function reset), between mailbox commands initiated
via ioctl (bsg) and those driver requested by the driver.
After setting SLI_ACTIVE flag for a port, there is a window in which the
driver will allow an ioctl to be initiated while the adapter is
initializing and issuing mailbox commands via polling. The polling logic
then gets confused.
Correct by having thread setting SLI_ACTIVE spot an active mailbox command
and allow it complete before proceeding.
Link: https://lore.kernel.org/r/20210921143008.64212-1-jsmart2021@gmail.com Co-developed-by: Nigel Kirkland <nkirkland2304@gmail.com> Signed-off-by: Nigel Kirkland <nkirkland2304@gmail.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When CAN_ISOTP_SF_BROADCAST is set in the CAN_ISOTP_OPTS flags the CAN_ISOTP
socket is switched into functional addressing mode, where only single frame
(SF) protocol data units can be send on the specified CAN interface and the
given tp.tx_id after bind().
In opposite to normal and extended addressing this socket does not register a
CAN-ID for reception which would be needed for a 1-to-1 ISOTP connection with a
segmented bi-directional data transfer.
Sending SFs on this socket is therefore a TX-only 'broadcast' operation.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Thomas Wagner <thwa1@web.de> Link: https://lore.kernel.org/r/20201206144731.4609-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A race condition was found in isotp_setsockopt() which allows to
change socket options after the socket was bound.
For the specific case of SF_BROADCAST support, this might lead to possible
use-after-free because can_rx_unregister() is not called.
Checking for the flag under the socket lock in isotp_bind() and taking
the lock in isotp_setsockopt() fixes the issue.
Fixes: 921ca574cd38 ("can: isotp: add SF_BROADCAST support for functional addressing") Link: https://lore.kernel.org/r/trinity-e6ae9efa-9afb-4326-84c0-f3609b9b8168-1620773528307@3c-app-gmx-bs06 Reported-by: Norbert Slusarek <nslusarek@gmx.net> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Norbert Slusarek <nslusarek@gmx.net> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The reproducer was trying to read /proc/$PID/smaps when calling
MADV_FREE at the mean time. MADV_FREE may split THPs if it is called
for partial THP. It may trigger the below race:
CPU A CPU B
----- -----
smaps walk: MADV_FREE:
page_mapcount()
PageCompound()
split_huge_page()
page = compound_head(page)
PageDoubleMap(page)
When calling PageDoubleMap() this page is not a tail page of THP anymore
so the BUG is triggered.
This could be fixed by elevated refcount of the page before calling
mapcount, but that would prevent it from counting migration entries, and
it seems overkilling because the race just could happen when PMD is
split so all PTE entries of tail pages are actually migration entries,
and smaps_account() does treat migration entries as mapcount == 1 as
Kirill pointed out.
Add a new parameter for smaps_account() to tell this entry is migration
entry then skip calling page_mapcount(). Don't skip getting mapcount
for device private entries since they do track references with mapcount.
Pagemap also has the similar issue although it was not reported. Fixed
it as well.
[shy828301@gmail.com: v4] Link: https://lkml.kernel.org/r/20220203182641.824731-1-shy828301@gmail.com
[nathan@kernel.org: avoid unused variable warning in pagemap_pmd_range()] Link: https://lkml.kernel.org/r/20220207171049.1102239-1-nathan@kernel.org Link: https://lkml.kernel.org/r/20220120202805.3369-1-shy828301@gmail.com Fixes: e9b61f19858a ("thp: reintroduce split_huge_page()") Signed-off-by: Yang Shi <shy828301@gmail.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reported-by: syzbot+1f52b3a18d5633fa7f82@syzkaller.appspotmail.com Acked-by: David Hildenbrand <david@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Jann Horn <jannh@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 054aa8d439b9 ("fget: check that the fd still exists after getting
a ref to it") fixed a race with getting a reference to a file just as it
was being closed. It was a fairly minimal patch, and I didn't think
re-checking the file pointer lookup would be a measurable overhead,
since it was all right there and cached.
But I was wrong, as pointed out by the kernel test robot.
The 'poll2' case of the will-it-scale.per_thread_ops benchmark regressed
quite noticeably. Admittedly it seems to be a very artificial test:
doing "poll()" system calls on regular files in a very tight loop in
multiple threads.
That means that basically all the time is spent just looking up file
descriptors without ever doing anything useful with them (not that doing
'poll()' on a regular file is useful to begin with). And as a result it
shows the extra "re-check fd" cost as a sore thumb.
Happily, the regression is fixable by just writing the code to loook up
the fd to be better and clearer. There's still a cost to verify the
file pointer, but now it's basically in the noise even for that
benchmark that does nothing else - and the code is more understandable
and has better comments too.
[ Side note: this patch is also a classic case of one that looks very
messy with the default greedy Myers diff - it's much more legible with
either the patience of histogram diff algorithm ]
An outgoing CPU is marked offline in a stop-machine handler and most
of that CPU's services stop at that point, including IRQ work queues.
However, that CPU must take another pass through the scheduler and through
a number of CPU-hotplug notifiers, many of which contain RCU readers.
In the past, these readers were not a problem because the outgoing CPU
has interrupts disabled, so that rcu_read_unlock_special() would not
be invoked, and thus RCU would never attempt to queue IRQ work on the
outgoing CPU.
This changed with the advent of the CONFIG_RCU_STRICT_GRACE_PERIOD
Kconfig option, in which rcu_read_unlock_special() is invoked upon exit
from almost all RCU read-side critical sections. Worse yet, because
interrupts are disabled, rcu_read_unlock_special() cannot immediately
report a quiescent state and will therefore attempt to defer this
reporting, for example, by queueing IRQ work. Which fails with a splat
because the CPU is already marked as being offline.
But it turns out that there is no need to report this quiescent state
because rcu_report_dead() will do this job shortly after the outgoing
CPU makes its final dive into the idle loop. This commit therefore
makes rcu_read_unlock_special() refrain from queuing IRQ work onto
outgoing CPUs.
Fixes: 44bad5b3cca2 ("rcu: Do full report for .need_qs for strict GPs") Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Jann Horn <jannh@google.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Alexander reported a circular lock dependency revealed by the mmap1 ltp
test:
LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1))
WARNING: possible circular locking dependency detected
5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1 Not tainted
------------------------------------------------------
mmap1/202299 is trying to acquire lock: 00000001892c0188 (css_set_lock){..-.}-{2:2}, at: obj_cgroup_release+0x4a/0xe0
but task is already holding lock: 00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sighand->siglock){-.-.}-{2:2}:
__lock_acquire+0x604/0xbd8
lock_acquire.part.0+0xe2/0x238
lock_acquire+0xb0/0x200
_raw_spin_lock_irqsave+0x6a/0xd8
__lock_task_sighand+0x90/0x190
cgroup_freeze_task+0x2e/0x90
cgroup_migrate_execute+0x11c/0x608
cgroup_update_dfl_csses+0x246/0x270
cgroup_subtree_control_write+0x238/0x518
kernfs_fop_write_iter+0x13e/0x1e0
new_sync_write+0x100/0x190
vfs_write+0x22c/0x2d8
ksys_write+0x6c/0xf8
__do_syscall+0x1da/0x208
system_call+0x82/0xb0
-> #0 (css_set_lock){..-.}-{2:2}:
check_prev_add+0xe0/0xed8
validate_chain+0x736/0xb20
__lock_acquire+0x604/0xbd8
lock_acquire.part.0+0xe2/0x238
lock_acquire+0xb0/0x200
_raw_spin_lock_irqsave+0x6a/0xd8
obj_cgroup_release+0x4a/0xe0
percpu_ref_put_many.constprop.0+0x150/0x168
drain_obj_stock+0x94/0xe8
refill_obj_stock+0x94/0x278
obj_cgroup_charge+0x164/0x1d8
kmem_cache_alloc+0xac/0x528
__sigqueue_alloc+0x150/0x308
__send_signal+0x260/0x550
send_signal+0x7e/0x348
force_sig_info_to_task+0x104/0x180
force_sig_fault+0x48/0x58
__do_pgm_check+0x120/0x1f0
pgm_check_handler+0x11e/0x180
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sighand->siglock);
lock(css_set_lock);
lock(&sighand->siglock);
lock(css_set_lock);
*** DEADLOCK ***
2 locks held by mmap1/202299:
#0: 00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
#1: 00000001892ad560 (rcu_read_lock){....}-{1:2}, at: percpu_ref_put_many.constprop.0+0x0/0x168
stack backtrace:
CPU: 15 PID: 202299 Comm: mmap1 Not tainted 5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1
Hardware name: IBM 3906 M04 704 (LPAR)
Call Trace:
dump_stack_lvl+0x76/0x98
check_noncircular+0x136/0x158
check_prev_add+0xe0/0xed8
validate_chain+0x736/0xb20
__lock_acquire+0x604/0xbd8
lock_acquire.part.0+0xe2/0x238
lock_acquire+0xb0/0x200
_raw_spin_lock_irqsave+0x6a/0xd8
obj_cgroup_release+0x4a/0xe0
percpu_ref_put_many.constprop.0+0x150/0x168
drain_obj_stock+0x94/0xe8
refill_obj_stock+0x94/0x278
obj_cgroup_charge+0x164/0x1d8
kmem_cache_alloc+0xac/0x528
__sigqueue_alloc+0x150/0x308
__send_signal+0x260/0x550
send_signal+0x7e/0x348
force_sig_info_to_task+0x104/0x180
force_sig_fault+0x48/0x58
__do_pgm_check+0x120/0x1f0
pgm_check_handler+0x11e/0x180
INFO: lockdep is turned off.
In this example a slab allocation from __send_signal() caused a
refilling and draining of a percpu objcg stock, resulted in a releasing
of another non-related objcg. Objcg release path requires taking the
css_set_lock, which is used to synchronize objcg lists.
This can create a circular dependency with the sighandler lock, which is
taken with the locked css_set_lock by the freezer code (to freeze a
task).
In general it seems that using css_set_lock to synchronize objcg lists
makes any slab allocations and deallocation with the locked css_set_lock
and any intervened locks risky.
To fix the problem and make the code more robust let's stop using
css_set_lock to synchronize objcg lists and use a new dedicated spinlock
instead.
Link: https://lkml.kernel.org/r/Yfm1IHmoGdyUR81T@carbon.dhcp.thefacebook.com Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") Signed-off-by: Roman Gushchin <guro@fb.com> Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Reviewed-by: Waiman Long <longman@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kasan has reported the following use after free on dev->iommu.
when a device probe fails and it is in process of freeing dev->iommu
in dev_iommu_free function, a deferred_probe_work_func runs in parallel
and tries to access dev->iommu->fwspec in of_iommu_configure path thus
causing use after free.
BUG: KASAN: use-after-free in of_iommu_configure+0xb4/0x4a4
Read of size 8 at addr ffffff87a2f1acb8 by task kworker/u16:2/153
There's list corruption on cgrp_cpuctx_list. This happens on the
following path:
perf_cgroup_switch: list_for_each_entry(cgrp_cpuctx_list)
cpu_ctx_sched_in
ctx_sched_in
ctx_pinned_sched_in
merge_sched_in
perf_cgroup_event_disable: remove the event from the list
Use list_for_each_entry_safe() to allow removing an entry during
iteration.
Fixes: 058fe1c0440e ("perf/core: Make cgroup switch visit only cpuctxs with cgroup events") Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220204004057.2961252-1-song@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port node does not have a unit-address, remove it.
This fixes the warnings:
lcd-controller@30320000: 'port' is a required property
lcd-controller@30320000: 'port@0' does not match any of the regexes:
'pinctrl-[0-9]+'
Messages around firmware download were incorrectly tagged as being related
to discovery trace events. Thus, firmware download status ended up dumping
the trace log as well as the firmware update message. As there were a
couple of log messages in this state, the trace log was dumped multiple
times.
Resolve this by converting from trace events to SLI events.
Link: https://lore.kernel.org/r/20220207180442.72836-1-jsmart2021@gmail.com Reviewed-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver is initiating NVMe PRLIs to determine device NVMe support. This
should not be occurring if CONFIG_NVME_FC support is disabled.
Correct this by changing the default value for FC4 support. Currently it
defaults to FCP and NVMe. With change, when NVME_FC support is not enabled
in the kernel, the default value is just FCP.
Link: https://lore.kernel.org/r/20220207180516.73052-1-jsmart2021@gmail.com Reviewed-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 43a08c3bdac4 ("can: isotp: isotp_sendmsg(): fix TX buffer concurrent
access in isotp_sendmsg()") introduced a new locking scheme that may render
the userspace application in a locking state when an error is detected.
This issue shows up under high load on simultaneously running isotp channels
with identical configuration which is against the ISO specification and
therefore breaks any reasonable PDU communication anyway.
Fixes: 43a08c3bdac4 ("can: isotp: isotp_sendmsg(): fix TX buffer concurrent access in isotp_sendmsg()") Link: https://lore.kernel.org/all/20220209073601.25728-1-socketcan@hartkopp.net Cc: stable@vger.kernel.org Cc: Ziyang Xuan <william.xuanziyang@huawei.com> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-Wunaligned-access is a new warning in clang that is default enabled for
arm and arm64 under certain circumstances within the clang frontend (see
LLVM commit below). On v5.17-rc2, an ARCH=arm allmodconfig build shows
1284 total/70 unique instances of this warning (most of the instances
are in header files), which is quite noisy.
To keep a normal build green through CONFIG_WERROR, only show this
warning with W=1, which will allow automated build systems to catch new
instances of the warning so that the total number can be driven down to
zero eventually since catching unaligned accesses at compile time would
be generally useful.
When setting the fan speed, i8k_set_fan() calls i8k_get_fan_status(),
causing an unnecessary SMM call since from the two users of this
function, only i8k_ioctl_unlocked() needs to know the new fan status
while dell_smm_write() ignores the new fan status.
Since SMM calls can be very slow while also making error reporting
difficult for dell_smm_write(), remove the function call from
i8k_set_fan() and call it separately in i8k_ioctl_unlocked().
_get_table_maxdiv() tries to access "clk_div_table" array out of bound
defined in phy-j721e-wiz.c. Add a sentinel entry to prevent
the following global-out-of-bounds error reported by enabling KASAN.
d97a9d7aea04 ("staging/speakup: Add inflection synth parameter")
introduced the inflection parameter, but happened to drop the pitch
parameter from the dectlk driver. This restores it.
Programmable lab power supplies made by GW Instek, such as the
GPP-2323, have a USB port exposing a serial port to control the device.
Stringing the supplied Windows driver, references to the ch341 chip are
found. Binding the existing ch341 driver to the VID/PID of the GPP-2323
("GW Instek USB2.0-Serial" as per the USB product name) works out of the
box, communication and control is now possible.
This patch should work with any GPP series power supply due to
similarities in the product line.
Under dummy_hcd, every available endpoint is *either* IN or OUT capable.
But with some real hardware, there are endpoints that support both IN and
OUT. In particular, the PLX 2380 has four available endpoints that each
support both IN and OUT.
raw-gadget currently gets confused and thinks that any endpoint that is
usable as an IN endpoint can never be used as an OUT endpoint.
Fix it by looking at the direction in the configured endpoint descriptor
instead of looking at the hardware capabilities.
With this change, I can use the PLX 2380 with raw-gadget.
Several users have reported that their Win10 does not enumerate UAC2
gadget with the existing wTerminalType set to
UAC_INPUT_TERMINAL_UNDEFINED/UAC_INPUT_TERMINAL_UNDEFINED, e.g.
https://github.com/raspberrypi/linux/issues/4587#issuecomment-926567213.
While the constant is officially defined by the USB terminal types
document, e.g. XMOS firmware for UAC2 (commonly used for Win10) defines
no undefined output terminal type in its usbaudio20.h header.
Therefore wTerminalType of EP-IN is set to
UAC_INPUT_TERMINAL_MICROPHONE and wTerminalType of EP-OUT to
UAC_OUTPUT_TERMINAL_SPEAKER for the UAC2 gadget.
The support the external role switch a variety of situations were
addressed, but the transition from USB_ROLE_HOST to USB_ROLE_NONE
leaves the host up which can cause some error messages when
switching from host to none, to gadget, to none, and then back
to host again.
xhci-hcd ee000000.usb: Abort failed to stop command ring: -110
xhci-hcd ee000000.usb: xHCI host controller not responding, assume dead
xhci-hcd ee000000.usb: HC died; cleaning up
usb 4-1: device not accepting address 6, error -108
usb usb4-port1: couldn't allocate usb_device
After this happens it will not act as a host again.
Fix this by releasing the host mode when transitioning to USB_ROLE_NONE.
Fixes: 0604160d8c0b ("usb: gadget: udc: renesas_usb3: Enhance role switch support") Cc: stable <stable@vger.kernel.org> Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Adam Ford <aford173@gmail.com> Link: https://lore.kernel.org/r/20220128223603.2362621-1-aford173@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With CPU re-ordering on write instructions, there might
be a chance that the HWO is set before the TRB is updated
with the new mapped buffer address.
And in the case where core is processing a list of TRBs
it is possible that it fetched the TRBs when the HWO is set
but before the buffer address is updated.
Prevent this by adding a memory barrier before the HWO
is updated to ensure that the core always process the
updated TRBs.
of_node_put should always be called on device nodes gotten from
of_get_*. Additionally, it should only be called after there are no
remaining users. To address the first issue, call of_node_put if later
steps in ulpi_register fail. To address the latter, call put_device if
device_register fails, which will call ulpi_dev_release if necessary.
Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT") Cc: stable <stable@vger.kernel.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Sean Anderson <sean.anderson@seco.com> Link: https://lore.kernel.org/r/20220127190004.1446909-3-sean.anderson@seco.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers are not unbound from the device when ulpi_unregister_interface
is called. Move of_node-freeing code to ulpi_dev_release which is called
only after all users are gone.
Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT") Cc: stable <stable@vger.kernel.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Sean Anderson <sean.anderson@seco.com> Link: https://lore.kernel.org/r/20220127190004.1446909-2-sean.anderson@seco.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ax88179_rx_fixup() contains several out-of-bounds accesses that can be
triggered by a malicious (or defective) USB device, in particular:
- The metadata array (hdr_off..hdr_off+2*pkt_cnt) can be out of bounds,
causing OOB reads and (on big-endian systems) OOB endianness flips.
- A packet can overlap the metadata array, causing a later OOB
endianness flip to corrupt data used by a cloned SKB that has already
been handed off into the network stack.
- A packet SKB can be constructed whose tail is far beyond its end,
causing out-of-bounds heap data to be considered part of the SKB's
data.
I have tested that this can be used by a malicious USB device to send a
bogus ICMPv6 Echo Request and receive an ICMPv6 Echo Reply in response
that contains random kernel heap data.
It's probably also possible to get OOB writes from this on a
little-endian system somehow - maybe by triggering skb_cow() via IP
options processing -, but I haven't tested that.
When the gadget driver hasn't been (yet) configured, and the cable is
connected to a HOST, the SFTDISCON gets cleared unconditionally, so the
HOST tries to enumerate it.
At the host side, this can result in a stuck USB port or worse. When
getting lucky, some dmesg can be observed at the host side:
new high-speed USB device number ...
device descriptor read/64, error -110
Fix it in drd, by checking the enabled flag before calling
dwc2_hsotg_core_connect(). It will be called later, once configured,
by the normal flow:
- udc_bind_to_driver
- usb_gadget_connect
- dwc2_hsotg_pullup
- dwc2_hsotg_core_connect
Commit effa453168a7 ("i2c: i801: Don't silently correct invalid transfer
size") revealed that ee1004_eeprom_read() did not properly limit how
many bytes to read at once.
In particular, i2c_smbus_read_i2c_block_data_or_emulated() takes the
length to read as an u8. If count == 256 after taking into account the
offset and page boundary, the cast to u8 overflows. And this is common
when user space tries to read the entire EEPROM at once.
To fix it, limit each read to I2C_SMBUS_BLOCK_MAX (32) bytes, already
the maximum length i2c_smbus_read_i2c_block_data_or_emulated() allows.
The poll man page says POLLRDNORM is equivalent to POLLIN when used as
an event.
$ man poll
<snip>
POLLRDNORM
Equivalent to POLLIN.
However, in n_tty driver, POLLRDNORM does not return until timeout even
if there is terminal input, whereas POLLIN returns.
The following test program works until kernel-3.17, but the test stops
in poll() after commit 57087d515441 ("tty: Fix spurious poll() wakeups").
[Steps to run test program]
$ cc -o test-pollrdnorm test-pollrdnorm.c
$ ./test-pollrdnorm
foo <-- Type in something from the terminal followed by [RET].
The string should be echoed back.
in vt_setactivate an almost identical code path has been patched
with array_index_nospec. In the VT_ACTIVATE path the user input
is from a system call argument instead of a usercopy.
For consistency both code paths should have the same mitigations
applied.
Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh
Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU
Amsterdam.
Co-developed-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220127144406.3589293-2-jakobkoschel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
array_index_nospec ensures that an out-of-bounds value is set to zero
on the transient path. Decreasing the value by one afterwards causes
a transient integer underflow. vsa.console should be decreased first
and then sanitized with array_index_nospec.
Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh
Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU
Amsterdam.
Co-developed-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220127144406.3589293-1-jakobkoschel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since struct mv88e6xxx_mdio_bus *mdio_bus is the bus->priv of something
allocated with mdiobus_alloc_size(), this means that mdiobus_free(bus)
will free the memory backing the mdio_bus as well. Therefore, the
mdio_bus->list element is freed memory, but we continue to iterate
through the list of MDIO buses using that list element.
To fix this, use the proper list iterator that handles element deletion
by keeping a copy of the list element next pointer.
Fixes: f53a2ce893b2 ("net: dsa: mv88e6xxx: don't use devres for mdiobus") Reported-by: Rafael Richter <rafael.richter@gin.de> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20220210174017.3271099-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
An ongoing workqueue populates the stats buffer. At the same time, a user
might query the statistics. While writing to the buffer is mutex-locked,
reading from the buffer wasn't. This could lead to buggy reads by ethtool.
This patch fixes the former blamed commit, but the bug was introduced in
the latter.
Signed-off-by: Colin Foster <colin.foster@in-advantage.com> Fixes: 1e1caa9735f90 ("ocelot: Clean up stats update deferred work") Fixes: a556c76adc052 ("net: mscc: Add initial Ocelot switch support") Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/all/20220210150451.416845-2-colin.foster@in-advantage.com/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The driver was avoiding offload for IPIP (at least) frames due to
parsing the inner header offsets incorrectly when trying to check
lengths.
This length check works for VXLAN frames but fails on IPIP frames
because skb_transport_offset points to the inner header in IPIP
frames, which meant the subtraction of transport_header from
inner_network_header returns a negative value (-20).
With the code before this patch, everything continued to work, but GSO
was being used to segment, causing throughputs of 1.5Gb/s per thread.
After this patch, throughput is more like 10Gb/s per thread for IPIP
traffic.
Fixes: e94d44786693 ("ice: Implement filter sync, NDO operations and bump version") Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Tested-by: Gurucharan G <gurucharanx.g@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The netdev should be unregistered before we are disconnecting from the
MAC/PHY so that the dev_close callback is called and the PHY and the
phylink workqueues are actually stopped before we are disconnecting and
destroying the phylink instance.
Fixes: 719479230893 ("dpaa2-eth: add MAC/PHY support through phylink") Signed-off-by: Robert-Ionut Alexa <robert-ionut.alexa@nxp.com> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Hardware interrupts are enabled during the pci probe, however,
they are not disabled during pci removal.
Disable all hardware interrupts during pci removal to avoid any
issues.
Fixes: e75377404726 ("amd-xgbe: Update PCI support to use new IRQ functions") Suggested-by: Selwin Sebastian <Selwin.Sebastian@amd.com> Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
It would be easy to craft a message containing an illegal binding table
update operation. This is handled correctly by the code, but the
corresponding warning printout is not rate limited as is should be.
We fix this now.
Fixes: b97bf3fd8f6a ("[TIPC] Initial merge") Signed-off-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed") Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23563 Comm: syz-executor.5 Not tainted 5.17.0-rc2-syzkaller-00064-gc36c04c2e132 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: 948d4f214fde ("veth: Add driver XDP") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
When uncloning an skb dst and its associated metadata, a new
dst+metadata is allocated and later replaces the old one in the skb.
This is helpful to have a non-shared dst+metadata attached to a specific
skb.
The issue is the uncloned dst+metadata is initialized with a refcount of
1, which is increased to 2 before attaching it to the skb. When
tun_dst_unclone returns, the dst+metadata is only referenced from a
single place (the skb) while its refcount is 2. Its refcount will never
drop to 0 (when the skb is consumed), leading to a memory leak.
Fix this by removing the call to dst_hold in tun_dst_unclone, as the
dst+metadata refcount is already 1.
Fixes: fc4099f17240 ("openvswitch: Fix egress tunnel info.") Cc: Pravin B Shelar <pshelar@ovn.org> Reported-by: Vlad Buslov <vladbu@nvidia.com> Tested-by: Vlad Buslov <vladbu@nvidia.com> Signed-off-by: Antoine Tenart <atenart@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
When uncloning an skb dst and its associated metadata a new dst+metadata
is allocated and the tunnel information from the old metadata is copied
over there.
The issue is the tunnel metadata has references to cached dst, which are
copied along the way. When a dst+metadata refcount drops to 0 the
metadata is freed including the cached dst entries. As they are also
referenced in the initial dst+metadata, this ends up in UaFs.
In practice the above did not happen because of another issue, the
dst+metadata was never freed because its refcount never dropped to 0
(this will be fixed in a subsequent patch).
Fix this by initializing the dst cache after copying the tunnel
information from the old metadata to also unshare the dst cache.
Fixes: d71785ffc7e7 ("net: add dst_cache to ovs vxlan lwtunnel") Cc: Paolo Abeni <pabeni@redhat.com> Reported-by: Vlad Buslov <vladbu@nvidia.com> Tested-by: Vlad Buslov <vladbu@nvidia.com> Signed-off-by: Antoine Tenart <atenart@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
When looking for a global mac index the extra NFP_TUN_PRE_TUN_IDX_BIT
that gets set if nfp_flower_is_supported_bridge is true is not taken
into account. Consequently the path that should release the ida_index
in cleanup is never triggered, causing messages like:
nfp 0000:02:00.0: nfp: Failed to offload MAC on br-ex.
nfp 0000:02:00.0: nfp: Failed to offload MAC on br-ex.
nfp 0000:02:00.0: nfp: Failed to offload MAC on br-ex.
after NFP_MAX_MAC_INDEX number of reconfigs. Ultimately this lead to
new tunnel flows not being offloaded.
Fix this by unsetting the NFP_TUN_PRE_TUN_IDX_BIT before checking if
the port is of type OTHER.
Fixes: 2e0bc7f3cb55 ("nfp: flower: encode mac indexes with pre-tunnel rule check") Signed-off-by: Louis Peens <louis.peens@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20220208101453.321949-1-simon.horman@corigine.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
As explained in commits: 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres")
mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.
The GSWIP switch is a platform device, so the initial set of constraints
that I thought would cause this (I2C or SPI buses which call ->remove on
->shutdown) do not apply. But there is one more which applies here.
If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the GSWIP switch driver on shutdown.
So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.
The gswip driver has the code structure in place for orderly mdiobus
removal, so just replace devm_mdiobus_alloc() with the non-devres
variant, and add manual free where necessary, to ensure that we don't
let devres free a still-registered bus.
Fixes: ac3a68d56651 ("net: phy: don't abuse devres in devm_mdiobus_register()") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
As explained in commits: 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres")
mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.
The Felix VSC9959 switch is a PCI device, so the initial set of
constraints that I thought would cause this (I2C or SPI buses which call
->remove on ->shutdown) do not apply. But there is one more which
applies here.
If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the felix switch driver on shutdown.
So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.
The felix driver has the code structure in place for orderly mdiobus
removal, so just replace devm_mdiobus_alloc_size() with the non-devres
variant, and add manual free where necessary, to ensure that we don't
let devres free a still-registered bus.
Fixes: ac3a68d56651 ("net: phy: don't abuse devres in devm_mdiobus_register()") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
As explained in commits: 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres")
mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.
The Starfighter 2 is a platform device, so the initial set of
constraints that I thought would cause this (I2C or SPI buses which call
->remove on ->shutdown) do not apply. But there is one more which
applies here.
If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the bcm_sf2 switch driver on shutdown.
So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.
The bcm_sf2 driver has the code structure in place for orderly mdiobus
removal, so just replace devm_mdiobus_alloc() with the non-devres
variant, and add manual free where necessary, to ensure that we don't
let devres free a still-registered bus.
Fixes: ac3a68d56651 ("net: phy: don't abuse devres in devm_mdiobus_register()") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
As explained in commits: 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres")
mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.
The ar9331 is an MDIO device, so the initial set of constraints that I
thought would cause this (I2C or SPI buses which call ->remove on
->shutdown) do not apply. But there is one more which applies here.
If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the ar9331 switch driver on shutdown.
So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.
The ar9331 driver doesn't have a complex code structure for mdiobus
removal, so just replace of_mdiobus_register with the devres variant in
order to be all-devres and ensure that we don't free a still-registered
bus.
Fixes: ac3a68d56651 ("net: phy: don't abuse devres in devm_mdiobus_register()") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
As explained in commits: 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres")
mdiobus_free() will panic when called from devm_mdiobus_free() <-
devres_release_all() <- __device_release_driver(), and that mdiobus was
not previously unregistered.
The mv88e6xxx is an MDIO device, so the initial set of constraints that
I thought would cause this (I2C or SPI buses which call ->remove on
->shutdown) do not apply. But there is one more which applies here.
If the DSA master itself is on a bus that calls ->remove from ->shutdown
(like dpaa2-eth, which is on the fsl-mc bus), there is a device link
between the switch and the DSA master, and device_links_unbind_consumers()
will unbind the Marvell switch driver on shutdown.
systemd-shutdown[1]: Powering off.
mv88e6085 0x0000000008b96000:00 sw_gl0: Link is Down
fsl-mc dpbp.9: Removing from iommu group 7
fsl-mc dpbp.8: Removing from iommu group 7
------------[ cut here ]------------
kernel BUG at drivers/net/phy/mdio_bus.c:677!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.16.5-00040-gdc05f73788e5 #15
pc : mdiobus_free+0x44/0x50
lr : devm_mdiobus_free+0x10/0x20
Call trace:
mdiobus_free+0x44/0x50
devm_mdiobus_free+0x10/0x20
devres_release_all+0xa0/0x100
__device_release_driver+0x190/0x220
device_release_driver_internal+0xac/0xb0
device_links_unbind_consumers+0xd4/0x100
__device_release_driver+0x4c/0x220
device_release_driver_internal+0xac/0xb0
device_links_unbind_consumers+0xd4/0x100
__device_release_driver+0x94/0x220
device_release_driver+0x28/0x40
bus_remove_device+0x118/0x124
device_del+0x174/0x420
fsl_mc_device_remove+0x24/0x40
__fsl_mc_device_remove+0xc/0x20
device_for_each_child+0x58/0xa0
dprc_remove+0x90/0xb0
fsl_mc_driver_remove+0x20/0x5c
__device_release_driver+0x21c/0x220
device_release_driver+0x28/0x40
bus_remove_device+0x118/0x124
device_del+0x174/0x420
fsl_mc_bus_remove+0x80/0x100
fsl_mc_bus_shutdown+0xc/0x1c
platform_shutdown+0x20/0x30
device_shutdown+0x154/0x330
kernel_power_off+0x34/0x6c
__do_sys_reboot+0x15c/0x250
__arm64_sys_reboot+0x20/0x30
invoke_syscall.constprop.0+0x4c/0xe0
do_el0_svc+0x4c/0x150
el0_svc+0x24/0xb0
el0t_64_sync_handler+0xa8/0xb0
el0t_64_sync+0x178/0x17c
So the same treatment must be applied to all DSA switch drivers, which
is: either use devres for both the mdiobus allocation and registration,
or don't use devres at all.
The Marvell driver already has a good structure for mdiobus removal, so
just plug in mdiobus_free and get rid of devres.
Fixes: ac3a68d56651 ("net: phy: don't abuse devres in devm_mdiobus_register()") Reported-by: Rafael Richter <Rafael.Richter@gin.de> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Daniel Klauer <daniel.klauer@gin.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
When 803.2ad mode enables a participating port, it should update
the slave-array. I have observed that the member links are participating
and are part of the active aggregator while the traffic is egressing via
only one member link (in a case where two links are participating). Via
kprobes I discovered that slave-arr has only one link added while
the other participating link wasn't part of the slave-arr.
I couldn't see what caused that situation but the simple code-walk
through provided me hints that the enable_port wasn't always associated
with the slave-array update.
Fixes: ee6377147409 ("bonding: Simplify the xmit function for modes that use xmit_hash") Signed-off-by: Mahesh Bandewar <maheshb@google.com> Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com> Link: https://lore.kernel.org/r/20220207222901.1795287-1-maheshb@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Setting the output of a GPIO to 1 using gpiod_set_value(), followed by
reading the same GPIO using gpiod_get_value(), will currently yield an
incorrect result.
This is because the SiFive GPIO device stores the output values in reg_set,
not reg_dat.
Supply the flag BGPIOF_READ_OUTPUT_REG_SET to bgpio_init() so that the
generic driver reads the correct register.
Commit 4a9af6cac050 ("ACPI: EC: Rework flushing of EC work while
suspended to idle") made acpi_ec_dispatch_gpe() check
pm_wakeup_pending(), but that is before canceling the SCI wakeup,
so pm_wakeup_pending() is always true. This causes the loop in
acpi_ec_dispatch_gpe() to always terminate after one iteration which
may not be correct.
Address this issue by canceling the SCI wakeup earlier, from
acpi_ec_dispatch_gpe() itself.
Fixes: 4a9af6cac050 ("ACPI: EC: Rework flushing of EC work while suspended to idle") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
In the function panel_simple_probe() the pointer panel->desc is
assigned to the passed pointer desc. If function panel_dpi_probe()
is called panel->desc will be updated, but further on only desc
will be evaluated. So update the desc pointer to be able to use
the data from the function panel_dpi_probe().
Fixes: 4a1d0dbc8332 ("drm/panel: simple: add panel-dpi support") Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Cc: Marek Vasut <marex@denx.de> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch>
To: dri-devel@lists.freedesktop.org Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Marek Vasut <marex@denx.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220201110153.3479-1-cniedermaier@dh-electronics.com Signed-off-by: Sasha Levin <sashal@kernel.org>
From 4.17 onwards the ixgbevf driver uses build_skb() to build an skb
around new data in the page buffer shared with the ixgbe PF.
This uses either a 2K or 3K buffer, and offsets the DMA mapping by
NET_SKB_PAD + NET_IP_ALIGN. When using a smaller buffer RXDCTL is set to
ensure the PF does not write a full 2K bytes into the buffer, which is
actually 2K minus the offset.
However on the 82599 virtual function, the RXDCTL mechanism is not
available. The driver attempts to work around this by using the SET_LPE
mailbox method to lower the maximm frame size, but the ixgbe PF driver
ignores this in order to keep the PF and all VFs in sync[0].
This means the PF will write up to the full 2K set in SRRCTL, causing it
to write NET_SKB_PAD + NET_IP_ALIGN bytes past the end of the buffer.
With 4K pages split into two buffers, this means it either writes
NET_SKB_PAD + NET_IP_ALIGN bytes past the first buffer (and into the
second), or NET_SKB_PAD + NET_IP_ALIGN bytes past the end of the DMA
mapping.
Avoid this by only enabling build_skb when using "large" buffers (3K).
These are placed in each half of an order-1 page, preventing the PF from
writing past the end of the mapping.
[0]: Technically it only ever raises the max frame size, see
ixgbe_set_vf_lpe() in ixgbe_sriov.c
Fixes: f15c5ba5b6cd ("ixgbevf: add support for using order 1 pages to receive large frames") Signed-off-by: Samuel Mendoza-Jonas <samjonas@amazon.com> Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
If the copy back to userland fails for the FASTRPC_IOCTL_ALLOC_DMA_BUFF
ioctl(), we shouldn't assume that 'buf->dmabuf' is still valid. In fact,
dma_buf_fd() called fd_install() before, i.e. "consumed" one reference,
leaving us with none.
Calling dma_buf_put() will therefore put a reference we no longer own,
leading to a valid file descritor table entry for an already released
'file' object which is a straight use-after-free.
Simply avoid calling dma_buf_put() and rely on the process exit code to
do the necessary cleanup, if needed, i.e. if the file descriptor is
still valid.
Fixes: 6cffd79504ce ("misc: fastrpc: Add support for dmabuf exporter") Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Mathias Krause <minipli@grsecurity.net> Link: https://lore.kernel.org/r/20220127130218.809261-1-minipli@grsecurity.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The 2711 pixel valve can't produce odd horizontal timings, and
checks were added to vc4_hdmi_encoder_atomic_check and
vc4_hdmi_encoder_mode_valid to filter out/block selection of
such modes.
Modes with DRM_MODE_FLAG_DBLCLK double all the horizontal timing
values before programming them into the PV. The PV values,
therefore, can not be odd, and so the modes can be supported.
If the parent GPIO controller is a sleeping controller (e.g. a GPIO
controller connected to I2C), getting or setting a GPIO triggers a
might_sleep() warning. This happens because the GPIO Aggregator takes
the can_sleep flag into account only for its internal locking, not for
calling into the parent GPIO controller.
Fix this by using the gpiod_[gs]et*_cansleep() APIs when calling into a
sleeping GPIO controller.
Consider a case where ffs_func_eps_disable is called from
ffs_func_disable as part of composition switch and at the
same time ffs_epfile_release get called from userspace.
ffs_epfile_release will free up the read buffer and call
ffs_data_closed which in turn destroys ffs->epfiles and
mark it as NULL. While this was happening the driver has
already initialized the local epfile in ffs_func_eps_disable
which is now freed and waiting to acquire the spinlock. Once
spinlock is acquired the driver proceeds with the stale value
of epfile and tries to free the already freed read buffer
causing use-after-free.
Fix this races by taking epfiles local copy & assigning it under
spinlock and if epfiles(local) is null then update it in ffs->epfiles
then finally destroy it.
Extending the scope further from the race, protecting the ep related
structures, and concurrent accesses.
The correct property name is 'assigned-clock-parents', not
'assigned-clocks-parents'. Though if the platform works with the typo, one
has to wonder if the property is even needed.
TX_PROT_BUS_WIDTH and RX_PROT_BUS_WIDTH are single registers with
separate bit fields for each lane. The code in xpsgtr_phy_init_sgmii was
not preserving the existing register value for other lanes, so enabling
the PHY in SGMII mode on one lane zeroed out the settings for all other
lanes, causing other PS-GTR peripherals such as USB3 to malfunction.
Use xpsgtr_clr_set to only manipulate the desired bits in the register.
Fixes: 4a33bea00314 ("phy: zynqmp: Add PHY driver for the Xilinx ZynqMP Gigabit Transceiver") Signed-off-by: Robert Hancock <robert.hancock@calian.com> Acked-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Link: https://lore.kernel.org/r/20220126001600.1592218-1-robert.hancock@calian.com Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The dt-bindings for the UART controller only allow the following values
for Meson8 SoCs:
- "amlogic,meson8b-uart", "amlogic,meson-ao-uart"
- "amlogic,meson8b-uart"
Use the correct fallback compatible string "amlogic,meson-ao-uart" for
AO UART. Drop the "amlogic,meson-uart" compatible string from the EE
domain UART controllers.
Also update the order of the clocks to match the order defined in the
yaml bindings.
Fixes: b02d6e73f5fc96 ("ARM: dts: meson8b: use stable UART bindings with correct gate clock") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Link: https://lore.kernel.org/r/20211227180026.4068352-4-martin.blumenstingl@googlemail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
The dt-bindings for the UART controller only allow the following values
for Meson8 SoCs:
- "amlogic,meson8-uart", "amlogic,meson-ao-uart"
- "amlogic,meson8-uart"
Use the correct fallback compatible string "amlogic,meson-ao-uart" for
AO UART. Drop the "amlogic,meson-uart" compatible string from the EE
domain UART controllers.
Also update the order of the clocks to match the order defined in the
yaml schema.
Fixes: 6ca77502050eff ("ARM: dts: meson8: use stable UART bindings with correct gate clock") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Link: https://lore.kernel.org/r/20211227180026.4068352-3-martin.blumenstingl@googlemail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
The dt-bindings for the UART controller only allow the following values
for Meson6 SoCs:
- "amlogic,meson6-uart", "amlogic,meson-ao-uart"
- "amlogic,meson6-uart"
Use the correct fallback compatible string "amlogic,meson-ao-uart" for
AO UART. Drop the "amlogic,meson-uart" compatible string from the EE
domain UART controllers.
Commit e428e250fde6 ("ARM: dts: Configure system timers for omap3")
caused a timer regression for beagleboard revision c where the system
clockevent stops working if omap3isp module is unloaded.
Turns out we still have beagleboard revisions a-b4 capacitor c70 quirks
applied that limit the usable timers for no good reason. This also affects
the power management as we use the system clock instead of the 32k clock
source.
Let's fix the issue by adding a new omap3-beagle-ab4.dts for the old timer
quirks. This allows us to remove the timer quirks for later beagleboard
revisions. We also need to update the related timer quirk check for the
correct compatible property.
Fixes: e428e250fde6 ("ARM: dts: Configure system timers for omap3") Cc: linux-kernel@vger.kernel.org Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Herring <robh+dt@kernel.org> Reported-by: Jarkko Nikula <jarkko.nikula@bitmer.com> Tested-by: Jarkko Nikula <jarkko.nikula@bitmer.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Bits 5:6 (i.e., shift 5, mask 0x3) are correct for RK3399, according to
the TRM.
There are a few other small differences between the 3288 and 3368
definitions that were swapped in commit 7707f7227f09. I reviewed them to
the best of my ability according to the RK3399 TRM and fixed them up.
This fixes IOMMU issues (and display errors) when testing with BG24
color formats.
Fixes: 7707f7227f09 ("drm/rockchip: Add support for afbc") Cc: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Cc: <stable@vger.kernel.org> Signed-off-by: Brian Norris <briannorris@chromium.org> Tested-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220119161104.1.I1d01436bef35165a8cdfe9308789c0badb5ff46a@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race
related to the EC GPE") wakeup interrupts occurring immediately after
the one discarded by acpi_s2idle_wake() may be missed. Moreover, if
the SCI triggers again immediately after the rearming in
acpi_s2idle_wake(), that wakeup may be missed too.
The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup()
when pm_wakeup_irq is 0, but that's not the case any more after the
interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is
cleared by the pm_wakeup_clear() call in s2idle_loop(). However,
there may be wakeup interrupts occurring in that time frame and if
that happens, they will be missed.
To address that issue first move the clearing of pm_wakeup_irq to
the point at which it is known that the interrupt causing
acpi_s2idle_wake() to tun will be discarded, before rearming the SCI
for wakeup. Moreover, because that only reduces the size of the
time window in which the issue may manifest itself, allow
pm_system_irq_wakeup() to register two second wakeup interrupts in
a row and, when discarding the first one, replace it with the second
one. [Of course, this assumes that only one wakeup interrupt can be
discarded in one go, but currently that is the case and I am not
aware of any plans to change that.]
Fixes: e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE") Cc: 5.4+ <stable@vger.kernel.org> # 5.4+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The original version of the IORT PMCG definition had an oversight
wherein there was no way to describe the second register page for an
implementation using the recommended RELOC_CTRS feature. Although the
spec was fixed, and the final patches merged to ACPICA and Linux written
against the new version, it seems that some old firmware based on the
original revision has survived and turned up in the wild.
Add a check for the original PMCG definition, and avoid filling in the
second memory resource with nonsense if so. Otherwise it is likely that
something horrible will happen when the PMCG driver attempts to probe.
Reported-by: Michael Petlan <mpetlan@redhat.com> Fixes: 24e516049360 ("ACPI/IORT: Add support for PMCG") Cc: <stable@vger.kernel.org> # 5.2.x Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Link: https://lore.kernel.org/r/75628ae41c257fb73588f7bf1c4459160e04be2b.1643916258.git.robin.murphy@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
AER is not backed by a real request, hence we should not incorrectly
assume that when failing to send a nvme command, it is a normal request
but rather check if this is an aer and if so complete the aer (similar
to the normal completion path).
Cc: stable@vger.kernel.org Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SocFPGA machine since commit b3ca9888f35f ("reset: socfpga: add an
early reset driver for SoCFPGA") uses reset controller, so it should
select RESET_CONTROLLER explicitly. Selecting ARCH_HAS_RESET_CONTROLLER
is not enough because it affects only default choice still allowing a
non-buildable configuration:
/usr/bin/arm-linux-gnueabi-ld: arch/arm/mach-socfpga/socfpga.o: in function `socfpga_init_irq':
arch/arm/mach-socfpga/socfpga.c:56: undefined reference to `socfpga_reset_init'
Reported-by: kernel test robot <lkp@intel.com> Cc: <stable@vger.kernel.org> Fixes: b3ca9888f35f ("reset: socfpga: add an early reset driver for SoCFPGA") Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Signed-off-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, SD card fails to mount due to the following pinctrl error:
[ 11.170000] imx23-pinctrl 80018000.pinctrl: pin SSP1_DETECT already requested by 80018000.pinctrl; cannot claim for 80010000.spi
[ 11.180000] imx23-pinctrl 80018000.pinctrl: pin-65 (80010000.spi) status -22
[ 11.190000] imx23-pinctrl 80018000.pinctrl: could not request pin 65 (SSP1_DETECT) from group mmc0-pins-fixup.0 on device 80018000.pinctrl
[ 11.200000] mxs-mmc 80010000.spi: Error applying setting, reverse things back
Fix it by removing the MX23_PAD_SSP1_DETECT pin from the hog group as it
is already been used by the mmc0-pins-fixup pinctrl group.
With this change the rootfs can be mounted and the imx23-evk board can
boot successfully.
From version 2.38, binutils default to ISA spec version 20191213. This
means that the csr read/write (csrr*/csrw*) instructions and fence.i
instruction has separated from the `I` extension, become two standalone
extensions: Zicsr and Zifencei. As the kernel uses those instruction,
this causes the following build failure:
Set vmcs.GUEST_PENDING_DBG_EXCEPTIONS.BS, a.k.a. the pending single-step
breakpoint flag, when re-injecting a #DB with RFLAGS.TF=1, and STI or
MOVSS blocking is active. Setting the flag is necessary to make VM-Entry
consistency checks happy, as VMX has an invariant that if RFLAGS.TF is
set and STI/MOVSS blocking is true, then the previous instruction must
have been STI or MOV/POP, and therefore a single-step #DB must be pending
since the RFLAGS.TF cannot have been set by the previous instruction,
i.e. the one instruction delay after setting RFLAGS.TF must have already
expired.
Normally, the CPU sets vmcs.GUEST_PENDING_DBG_EXCEPTIONS.BS appropriately
when recording guest state as part of a VM-Exit, but #DB VM-Exits
intentionally do not treat the #DB as "guest state" as interception of
the #DB effectively makes the #DB host-owned, thus KVM needs to manually
set PENDING_DBG.BS when forwarding/re-injecting the #DB to the guest.
Note, although this bug can be triggered by guest userspace, doing so
requires IOPL=3, and guest userspace running with IOPL=3 has full access
to all I/O ports (from the guest's perspective) and can crash/reboot the
guest any number of ways. IOPL=3 is required because STI blocking kicks
in if and only if RFLAGS.IF is toggled 0=>1, and if CPL>IOPL, STI either
takes a #GP or modifies RFLAGS.VIF, not RFLAGS.IF.
MOVSS blocking can be initiated by userspace, but can be coincident with
a #DB if and only if DR7.GD=1 (General Detect enabled) and a MOV DR is
executed in the MOVSS shadow. MOV DR #GPs at CPL>0, thus MOVSS blocking
is problematic only for CPL0 (and only if the guest is crazy enough to
access a DR in a MOVSS shadow). All other sources of #DBs are either
suppressed by MOVSS blocking (single-step, code fetch, data, and I/O),
are mutually exclusive with MOVSS blocking (T-bit task switch), or are
already handled by KVM (ICEBP, a.k.a. INT1).
This bug was originally found by running tests[1] created for XSA-308[2].
Note that Xen's userspace test emits ICEBP in the MOVSS shadow, which is
presumably why the Xen bug was deemed to be an exploitable DOS from guest
userspace. KVM already handles ICEBP by skipping the ICEBP instruction
and thus clears MOVSS blocking as a side effect of its "emulation".
projects / users / dwmw2 / linux.git / log