When using the PtrAuth feature in a guest, we need to save the host's
keys before allowing the guest to program them. For that, we dump
them in a per-CPU data structure (the so called host context).
But both call sites that do this are in preemptible context,
which may end up in disaster should the vcpu thread get preempted
before reentering the guest.
Instead, save the keys eagerly on each vcpu_load(). This has an
increased overhead, but is at least safe.
On a VHE system, the EL1 state is left in the CPU most of the time,
and only syncronized back to memory when vcpu_put() is called (most
of the time on preemption).
Which means that when injecting an exception, we'd better have a way
to either:
(1) write directly to the EL1 sysregs
(2) synchronize the state back to memory, and do the changes there
For an AArch64, we already do (1), so we are safe. Unfortunately,
doing the same thing for AArch32 would be pretty invasive. Instead,
we can easily implement (2) by calling the put/load architectural
backends, and keep preemption disabled. We can then reload the
state back into EL1.
After commit 6d232b29cfce ("ACPICA: Dispatcher: always generate buffer
objects for ASL create_field() operator") ACPICA creates buffers even
when new fields are small enough to fit into an integer.
Many SNC calls counted on the old behaviour.
Since sony-laptop already handles the INTEGER/BUFFER case in
sony_nc_buffer_call, switch sony_nc_int_call to use its more generic
function instead.
Since the switch of floppy driver to blk-mq, the contended (fdc_busy) case
in floppy_queue_rq() is not handled correctly.
In case we reach floppy_queue_rq() with fdc_busy set (i.e. with the floppy
locked due to another request still being in-flight), we put the request
on the list of requests and return BLK_STS_OK to the block core, without
actually scheduling delayed work / doing further processing of the
request. This means that processing of this request is postponed until
another request comes and passess uncontended.
Which in some cases might actually never happen and we keep waiting
indefinitely. The simple testcase is
for i in `seq 1 2000`; do echo -en $i '\r'; blkid --info /dev/fd0 2> /dev/null; done
run in quemu. That reliably causes blkid eventually indefinitely hanging
in __floppy_read_block_0() waiting for completion, as the BIO callback
never happens, and no further IO is ever submitted on the (non-existent)
floppy device. This was observed reliably on qemu-emulated device.
Fix that by not queuing the request in the contended case, and return
BLK_STS_RESOURCE instead, so that blk core handles the request
rescheduling and let it pass properly non-contended later.
Over the years, the code in mmc_sdio_init_card() has grown to become quite
messy. Unfortunate this has also lead to that several paths are leaking
memory in form of an allocated struct mmc_card, which includes additional
data, such as initialized struct device for example.
Unfortunate, it's a too complex task find each offending commit. Therefore,
this change fixes all memory leaks at once.
During some scenarios mmc_sdio_init_card() runs a retry path for the UHS-I
specific initialization, which leads to removal of the previously allocated
card. A new card is then re-allocated while retrying.
However, in one of the corresponding error paths we may end up to remove an
already removed card, which likely leads to a NULL pointer exception. So,
let's fix this.
Fixes: 5fc3d80ef496 ("mmc: sdio: don't use rocr to check if the card could support UHS mode")
Cc: <email address hidden>
Signed-off-by: Ulf Hansson <email address hidden>
Link: https://<email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
380b60c...
by
Ludovic Desroches <email address hidden>
