linux-stable.git/drivers/hv, branch v5.4.201

random: remove unused irq_flags argument from add_interrupt_randomness()

2022-06-22T12:11:06+00:00

commit 703f7066f40599c290babdb79dd61319264987e9 upstream.

Since commit
   ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Dexuan Cui 
Cc: H. Peter Anvin 
Cc: Haiyang Zhang 
Cc: Ingo Molnar 
Cc: K. Y. Srinivasan 
Cc: Stephen Hemminger 
Cc: Thomas Gleixner 
Cc: Wei Liu 
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior 
Acked-by: Wei Liu 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Prevent load re-ordering when reading ring buffer

2022-04-20T07:19:36+00:00

[ Upstream commit b6cae15b5710c8097aad26a2e5e752c323ee5348 ]

When reading a packet from a host-to-guest ring buffer, there is no
memory barrier between reading the write index (to see if there is
a packet to read) and reading the contents of the packet. The Hyper-V
host uses store-release when updating the write index to ensure that
writes of the packet data are completed first. On the guest side,
the processor can reorder and read the packet data before the write
index, and sometimes get stale packet data. Getting such stale packet
data has been observed in a reproducible case in a VM on ARM64.

Fix this by using virt_load_acquire() to read the write index,
ensuring that reads of the packet data cannot be reordered
before it. Preventing such reordering is logically correct, and
with this change, getting stale data can no longer be reproduced.

Signed-off-by: Michael Kelley 
Reviewed-by: Andrea Parri (Microsoft) 
Link: https://lore.kernel.org/r/1648394710-33480-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Fix potential crash on module unload

2022-04-15T12:18:37+00:00

[ Upstream commit 792f232d57ff28bbd5f9c4abe0466b23d5879dc8 ]

The vmbus driver relies on the panic notifier infrastructure to perform
some operations when a panic event is detected. Since vmbus can be built
as module, it is required that the driver handles both registering and
unregistering such panic notifier callback.

After commit 74347a99e73a ("x86/Hyper-V: Unload vmbus channel in hv panic callback")
though, the panic notifier registration is done unconditionally in the module
initialization routine whereas the unregistering procedure is conditionally
guarded and executes only if HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE capability
is set.

This patch fixes that by unconditionally unregistering the panic notifier
in the module's exit routine as well.

Fixes: 74347a99e73a ("x86/Hyper-V: Unload vmbus channel in hv panic callback")
Signed-off-by: Guilherme G. Piccoli 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20220315203535.682306-1-gpiccoli@igalia.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

hv_balloon: rate-limit "Unhandled message" warning

2022-04-15T12:18:15+00:00

[ Upstream commit 1d7286729aa616772be334eb908e11f527e1e291 ]

For a couple of times I have encountered a situation where

  hv_balloon: Unhandled message: type: 12447

is being flooded over 1 million times per second with various values,
filling the log and consuming cycles, making debugging difficult.

Add rate limiting to the message.

Most other Hyper-V drivers already have similar rate limiting in their
message callbacks.

The cause of the floods in my case was probably fixed by 96d9d1fa5cd5
("Drivers: hv: balloon: account for vmbus packet header in
max_pkt_size").

Fixes: 9aa8b50b2b3d ("Drivers: hv: Add Hyper-V balloon driver")
Signed-off-by: Anssi Hannula 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20220222141400.98160-1-anssi.hannula@bitwise.fi
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Fix memory leak in vmbus_add_channel_kobj

2022-02-23T11:00:00+00:00

[ Upstream commit 8bc69f86328e87a0ffa79438430cc82f3aa6a194 ]

kobject_init_and_add() takes reference even when it fails.
According to the doc of kobject_init_and_add()：

   If this function returns an error, kobject_put() must be called to
   properly clean up the memory associated with the object.

Fix memory leak by calling kobject_put().

Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info")
Signed-off-by: Miaoqian Lin 
Reviewed-by: Juan Vazquez 
Link: https://lore.kernel.org/r/20220203173008.43480-1-linmq006@gmail.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

hyperv/vmbus: include linux/bitops.h

2021-11-17T08:48:20+00:00

[ Upstream commit 8017c99680fa65e1e8d999df1583de476a187830 ]

On arm64 randconfig builds, hyperv sometimes fails with this
error:

In file included from drivers/hv/hv_trace.c:3:
In file included from drivers/hv/hyperv_vmbus.h:16:
In file included from arch/arm64/include/asm/sync_bitops.h:5:
arch/arm64/include/asm/bitops.h:11:2: error: only  can be included directly
In file included from include/asm-generic/bitops/hweight.h:5:
include/asm-generic/bitops/arch_hweight.h:9:9: error: implicit declaration of function '__sw_hweight32' [-Werror,-Wimplicit-function-declaration]
include/asm-generic/bitops/atomic.h:17:7: error: implicit declaration of function 'BIT_WORD' [-Werror,-Wimplicit-function-declaration]

Include the correct header first.

Signed-off-by: Arnd Bergmann 
Link: https://lore.kernel.org/r/20211018131929.2260087-1-arnd@kernel.org
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

hv_utils: Fix passing zero to 'PTR_ERR' warning

2021-07-14T14:53:16+00:00

[ Upstream commit c6a8625fa4c6b0a97860d053271660ccedc3d1b3 ]

Sparse warn this:

drivers/hv/hv_util.c:753 hv_timesync_init() warn:
 passing zero to 'PTR_ERR'

Use PTR_ERR_OR_ZERO instead of PTR_ERR to fix this.

Signed-off-by: YueHaibing 
Link: https://lore.kernel.org/r/20210514070116.16800-1-yuehaibing@huawei.com
[ wei: change %ld to %d ]
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Increase wait time for VMbus unload

2021-05-14T07:44:22+00:00

[ Upstream commit 77db0ec8b7764cb9b09b78066ebfd47b2c0c1909 ]

When running in Azure, disks may be connected to a Linux VM with
read/write caching enabled. If a VM panics and issues a VMbus
UNLOAD request to Hyper-V, the response is delayed until all dirty
data in the disk cache is flushed.  In extreme cases, this flushing
can take 10's of seconds, depending on the disk speed and the amount
of dirty data. If kdump is configured for the VM, the current 10 second
timeout in vmbus_wait_for_unload() may be exceeded, and the UNLOAD
complete message may arrive well after the kdump kernel is already
running, causing problems.  Note that no problem occurs if kdump is
not enabled because Hyper-V waits for the cache flush before doing
a reboot through the BIOS/UEFI code.

Fix this problem by increasing the timeout in vmbus_wait_for_unload()
to 100 seconds. Also output periodic messages so that if anyone is
watching the serial console, they won't think the VM is completely
hung.

Fixes: 911e1987efc8 ("Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload")
Signed-off-by: Michael Kelley 
Reviewed-by: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/1618894089-126662-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()

2021-03-04T09:26:24+00:00

[ Upstream commit e3fa4b747f085d2cda09bba0533b86fa76038635 ]

When channel->device_obj is non-NULL, vmbus_onoffer_rescind() could
invoke put_device(), that will eventually release the device and free
the channel object (cf. vmbus_device_release()).  However, a pointer
to the object is dereferenced again later to load the primary_channel.
The use-after-free can be avoided by noticing that this load/check is
redundant if device_obj is non-NULL: primary_channel must be NULL if
device_obj is non-NULL, cf. vmbus_add_channel_work().

Fixes: 54a66265d6754b ("Drivers: hv: vmbus: Fix rescind handling")
Reported-by: Juan Vazquez 
Signed-off-by: Andrea Parri (Microsoft) 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20201209070827.29335-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Allow cleanup of VMBUS_CONNECT_CPU if disconnected

2020-11-24T12:29:23+00:00

commit 92e4dc8b05663d6539b1b8375f3b1cf7b204cfe9 upstream.

When invoking kexec() on a Linux guest running on a Hyper-V host, the
kernel panics.

    RIP: 0010:cpuhp_issue_call+0x137/0x140
    Call Trace:
    __cpuhp_remove_state_cpuslocked+0x99/0x100
    __cpuhp_remove_state+0x1c/0x30
    hv_kexec_handler+0x23/0x30 [hv_vmbus]
    hv_machine_shutdown+0x1e/0x30
    machine_shutdown+0x10/0x20
    kernel_kexec+0x6d/0x96
    __do_sys_reboot+0x1ef/0x230
    __x64_sys_reboot+0x1d/0x20
    do_syscall_64+0x6b/0x3d8
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

This was due to hv_synic_cleanup() callback returning -EBUSY to
cpuhp_issue_call() when tearing down the VMBUS_CONNECT_CPU, even
if the vmbus_connection.conn_state = DISCONNECTED. hv_synic_cleanup()
should succeed in the case where vmbus_connection.conn_state
is DISCONNECTED.

Fix is to add an extra condition to test for
vmbus_connection.conn_state == CONNECTED on the VMBUS_CONNECT_CPU and
only return early if true. This way the kexec() path can still shut
everything down while preserving the initial behavior of preventing
CPU offlining on the VMBUS_CONNECT_CPU while the VM is running.

Fixes: 8a857c55420f29 ("Drivers: hv: vmbus: Always handle the VMBus messages on CPU0")
Signed-off-by: Chris Co 
Reviewed-by: Andrea Parri (Microsoft) 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201110190118.15596-1-chrco@linux.microsoft.com
Signed-off-by: Wei Liu 
Signed-off-by: Greg Kroah-Hartman