kernel/linux.git, branch v5.7.4

Linux 5.7.4

2020-06-18T12:31:08+00:00

lib/vdso: Provide sanity check for cycles (again)

2020-06-18T12:31:08+00:00

commit 72ce778007e57e8996b4bebdec738fc5e1145fd2 upstream. The original x86 VDSO implementation checked for the validity of the clock source read by testing whether the returned signed cycles value is less than zero. This check was also used by the vdso read function to signal that the current selected clocksource is not VDSO capable. During the rework of the VDSO code the check was removed and replaced with a check for the clocksource mode being != NONE. This turned out to be a mistake because the check is necessary for paravirt and hyperv clock sources. The reason is that these clock sources have their own internal sequence counter to validate the clocksource at the point of reading it. This is necessary because the hypervisor can invalidate the clocksource asynchronously so a check during the VDSO data update is not sufficient. Having a separate indicator for the validity is slower than just validating the cycles value. The check for it being negative turned out to be the fastest implementation and safe as it would require an uptime of ~73 years with a 4GHz counter frequency to result in a false positive. Add an optional function to validate the cycles with a default implementation which allows the compiler to optimize it out for architectures which do not require it. Fixes: 5d51bee725cc ("clocksource: Add common vdso clock mode storage") Reported-by: Miklos Szeredi Signed-off-by: Thomas Gleixner Tested-by: Miklos Szeredi Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200606221531.963970768@linutronix.de Signed-off-by: Greg Kroah-Hartman

Linux 5.7.3

2020-06-17T14:43:05+00:00

serial: amba-pl011: Make sure we initialize the port.lock spinlock

2020-06-17T14:43:05+00:00

commit 8508f4cba308f785b2fd4b8c38849c117b407297 upstream. Valentine reported seeing: [ 3.626638] INFO: trying to register non-static key. [ 3.626639] the code is fine but needs lockdep annotation. [ 3.626640] turning off the locking correctness validator. [ 3.626644] CPU: 7 PID: 51 Comm: kworker/7:1 Not tainted 5.7.0-rc2-00115-g8c2e9790f196 #116 [ 3.626646] Hardware name: HiKey960 (DT) [ 3.626656] Workqueue: events deferred_probe_work_func [ 3.632476] sd 0:0:0:0: [sda] Optimal transfer size 8192 bytes not a multiple of physical block size (16384 bytes) [ 3.640220] Call trace: [ 3.640225] dump_backtrace+0x0/0x1b8 [ 3.640227] show_stack+0x20/0x30 [ 3.640230] dump_stack+0xec/0x158 [ 3.640234] register_lock_class+0x598/0x5c0 [ 3.640235] __lock_acquire+0x80/0x16c0 [ 3.640236] lock_acquire+0xf4/0x4a0 [ 3.640241] _raw_spin_lock_irqsave+0x70/0xa8 [ 3.640245] uart_add_one_port+0x388/0x4b8 [ 3.640248] pl011_register_port+0x70/0xf0 [ 3.640250] pl011_probe+0x184/0x1b8 [ 3.640254] amba_probe+0xdc/0x180 [ 3.640256] really_probe+0xe0/0x338 [ 3.640257] driver_probe_device+0x60/0xf8 [ 3.640259] __device_attach_driver+0x8c/0xd0 [ 3.640260] bus_for_each_drv+0x84/0xd8 [ 3.640261] __device_attach+0xe4/0x140 [ 3.640263] device_initial_probe+0x1c/0x28 [ 3.640265] bus_probe_device+0xa4/0xb0 [ 3.640266] deferred_probe_work_func+0x7c/0xb8 [ 3.640269] process_one_work+0x2c0/0x768 [ 3.640271] worker_thread+0x4c/0x498 [ 3.640272] kthread+0x14c/0x158 [ 3.640275] ret_from_fork+0x10/0x1c Which seems to be due to the fact that after allocating the uap structure, nothing initializes the spinlock. Its a little confusing, as uart_port_spin_lock_init() is one place where the lock is supposed to be initialized, but it has an exception for the case where the port is a console. This makes it seem like a deeper fix is needed to properly register the console, but I'm not sure what that entails, and Andy suggested that this approach is less invasive. Thus, this patch resolves the issue by initializing the spinlock in the driver, and resolves the resulting warning. Cc: Andy Shevchenko Cc: Russell King Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Reported-by: Valentin Schneider Reviewed-by: Andy Shevchenko Signed-off-by: John Stultz Reviewed-and-tested-by: Valentin Schneider Link: https://lore.kernel.org/r/20200428184050.6501-1-john.stultz@linaro.org Cc: Naresh Kamboju Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception

2020-06-17T14:43:05+00:00

commit 0370964dd3ff7d3d406f292cb443a927952cbd05 upstream. 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. Cc: stable@vger.kernel.org Reported-by: James Morse Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Save the host's PtrAuth keys in non-preemptible context

2020-06-17T14:43:05+00:00

commit ef3e40a7ea8dbe2abd0a345032cd7d5023b9684f upstream. 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. Cc: stable@vger.kernel.org Reviewed-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

platform/x86: sony-laptop: Make resuming thermal profile safer

2020-06-17T14:43:05+00:00

commit 476d60b1b4c8a2b14a53ef9b772058f35e604661 upstream. The thermal handle object may fail initialization when the module is loaded in the first place. Avoid attempting to use it on resume then. Fixes: 6d232b29cfce ("ACPICA: Dispatcher: always generate buffer objects for ASL create_field() operator") Reported-by: Dominik Mierzejewski Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207491 Signed-off-by: Mattia Dongili Signed-off-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman

platform/x86: sony-laptop: SNC calls should handle BUFFER types

2020-06-17T14:43:05+00:00

commit 47828d22539f76c8c9dcf2a55f18ea3a8039d8ef upstream. 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. Fixes: 6d232b29cfce ("ACPICA: Dispatcher: always generate buffer objects for ASL create_field() operator") Reported-by: Dominik Mierzejewski Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207491 Reported-by: William Bader Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1830150 Signed-off-by: Mattia Dongili Signed-off-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman

xen/pvcalls-back: test for errors when calling backend_connect()

2020-06-17T14:43:04+00:00

commit c8d70a29d6bbc956013f3401f92a4431a9385a3c upstream. backend_connect() can fail, so switch the device to connected only if no error occurred. Fixes: 0a9c75c2c7258f2 ("xen/pvcalls: xenbus state handling") Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross Link: https://lore.kernel.org/r/20200511074231.19794-1-jgross@suse.com Reviewed-by: Stefano Stabellini Signed-off-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman

block/floppy: fix contended case in floppy_queue_rq()

2020-06-17T14:43:04+00:00

commit 263c61581a38d0a5ad1f5f4a9143b27d68caeffd upstream. 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. Fixes: a9f38e1dec107a ("floppy: convert to blk-mq") Cc: stable@vger.kernel.org Tested-by: Libor Pechacek Signed-off-by: Jiri Kosina Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman