linux-stable.git, branch v4.9.185

Linux 4.9.185

2019-07-10T07:55:47+00:00

arm64: kaslr: keep modules inside module region when KASAN is enabled

2019-07-10T07:55:47+00:00

commit 6f496a555d93db7a11d4860b9220d904822f586a upstream.

When KASLR and KASAN are both enabled, we keep the modules where they
are, and randomize the placement of the kernel so it is within 2 GB
of the module region. The reason for this is that putting modules in
the vmalloc region (like we normally do when KASLR is enabled) is not
possible in this case, given that the entire vmalloc region is already
backed by KASAN zero shadow pages, and so allocating dedicated KASAN
shadow space as required by loaded modules is not possible.

The default module allocation window is set to [_etext - 128MB, _etext]
in kaslr.c, which is appropriate for KASLR kernels booted without a
seed or with 'nokaslr' on the command line. However, as it turns out,
it is not quite correct for the KASAN case, since it still intersects
the vmalloc region at the top, where attempts to allocate shadow pages
will collide with the KASAN zero shadow pages, causing a WARN() and all
kinds of other trouble. So cap the top end to MODULES_END explicitly
when running with KASAN.

Cc:  # 4.9+
Acked-by: Catalin Marinas 
Tested-by: Catalin Marinas 
Signed-off-by: Ard Biesheuvel 
[will: backport to 4.9.y]
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

dmaengine: imx-sdma: remove BD_INTR for channel0

2019-07-10T07:55:47+00:00

commit 3f93a4f297961c12bb17aa16cb3a4d1291823cae upstream.

It is possible for an irq triggered by channel0 to be received later
after clks are disabled once firmware loaded during sdma probe. If
that happens then clearing them by writing to SDMA_H_INTR won't work
and the kernel will hang processing infinite interrupts. Actually,
don't need interrupt triggered on channel0 since it's pollling
SDMA_H_STATSTOP to know channel0 done rather than interrupt in
current code, just clear BD_INTR to disable channel0 interrupt to
avoid the above case.
This issue was brought by commit 1d069bfa3c78 ("dmaengine: imx-sdma:
ack channel 0 IRQ in the interrupt handler") which didn't take care
the above case.

Fixes: 1d069bfa3c78 ("dmaengine: imx-sdma: ack channel 0 IRQ in the interrupt handler")
Cc: stable@vger.kernel.org #5.0+
Signed-off-by: Robin Gong 
Reported-by: Sven Van Asbroeck 
Tested-by: Sven Van Asbroeck 
Reviewed-by: Michael Olbrich 
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

MIPS: Add missing EHB in mtc0 -> mfc0 sequence.

2019-07-10T07:55:47+00:00

commit 0b24cae4d535045f4c9e177aa228d4e97bad212c upstream.

Add a missing EHB (Execution Hazard Barrier) in mtc0 -> mfc0 sequence.
Without this execution hazard barrier it's possible for the value read
back from the KScratch register to be the value from before the mtc0.

Reproducible on P5600 & P6600.

The hazard is documented in the MIPS Architecture Reference Manual Vol.
III: MIPS32/microMIPS32 Privileged Resource Architecture (MD00088), rev
6.03 table 8.1 which includes:

   Producer | Consumer | Hazard
  ----------|----------|----------------------------
   mtc0     | mfc0     | any coprocessor 0 register

Signed-off-by: Dmitry Korotin 
[paul.burton@mips.com:
  - Commit message tweaks.
  - Add Fixes tags.
  - Mark for stable back to v3.15 where P5600 support was introduced.]
Signed-off-by: Paul Burton 
Fixes: 3d8bfdd03072 ("MIPS: Use C0_KScratch (if present) to hold PGD pointer.")
Fixes: 829dcc0a956a ("MIPS: Add MIPS P5600 probe support")
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Greg Kroah-Hartman

IB/hfi1: Close PSM sdma_progress sleep window

2019-07-10T07:55:47+00:00

commit da9de5f8527f4b9efc82f967d29a583318c034c7 upstream.

The call to sdma_progress() is called outside the wait lock.

In this case, there is a race condition where sdma_progress() can return
false and the sdma_engine can idle.  If that happens, there will be no
more sdma interrupts to cause the wakeup and the user_sdma xmit will hang.

Fix by moving the lock to enclose the sdma_progress() call.

Also, delete busycount. The need for this was removed by:
commit bcad29137a97 ("IB/hfi1: Serve the most starved iowait entry first")

Cc: 
Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Reviewed-by: Gary Leshner 
Signed-off-by: Mike Marciniszyn 
Signed-off-by: Dennis Dalessandro 
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Greg Kroah-Hartman

KVM: LAPIC: Fix pending interrupt in IRR blocked by software disable LAPIC

2019-07-10T07:55:47+00:00

commit bb34e690e9340bc155ebed5a3d75fc63ff69e082 upstream.

Thomas reported that:

 | Background:
 |
 |    In preparation of supporting IPI shorthands I changed the CPU offline
 |    code to software disable the local APIC instead of just masking it.
 |    That's done by clearing the APIC_SPIV_APIC_ENABLED bit in the APIC_SPIV
 |    register.
 |
 | Failure:
 |
 |    When the CPU comes back online the startup code triggers occasionally
 |    the warning in apic_pending_intr_clear(). That complains that the IRRs
 |    are not empty.
 |
 |    The offending vector is the local APIC timer vector who's IRR bit is set
 |    and stays set.
 |
 | It took me quite some time to reproduce the issue locally, but now I can
 | see what happens.
 |
 | It requires apicv_enabled=0, i.e. full apic emulation. With apicv_enabled=1
 | (and hardware support) it behaves correctly.
 |
 | Here is the series of events:
 |
 |     Guest CPU
 |
 |     goes down
 |
 |       native_cpu_disable()
 |
 | 			apic_soft_disable();
 |
 |     play_dead()
 |
 |     ....
 |
 |     startup()
 |
 |       if (apic_enabled())
 |         apic_pending_intr_clear()	<- Not taken
 |
 |      enable APIC
 |
 |         apic_pending_intr_clear()	<- Triggers warning because IRR is stale
 |
 | When this happens then the deadline timer or the regular APIC timer -
 | happens with both, has fired shortly before the APIC is disabled, but the
 | interrupt was not serviced because the guest CPU was in an interrupt
 | disabled region at that point.
 |
 | The state of the timer vector ISR/IRR bits:
 |
 |     	     	       	        ISR     IRR
 | before apic_soft_disable()    0	      1
 | after apic_soft_disable()     0	      1
 |
 | On startup		      		 0	      1
 |
 | Now one would assume that the IRR is cleared after the INIT reset, but this
 | happens only on CPU0.
 |
 | Why?
 |
 | Because our CPU0 hotplug is just for testing to make sure nothing breaks
 | and goes through an NMI wakeup vehicle because INIT would send it through
 | the boots-trap code which is not really working if that CPU was not
 | physically unplugged.
 |
 | Now looking at a real world APIC the situation in that case is:
 |
 |     	     	       	      	ISR     IRR
 | before apic_soft_disable()    0	      1
 | after apic_soft_disable()     0	      1
 |
 | On startup		      		 0	      0
 |
 | Why?
 |
 | Once the dying CPU reenables interrupts the pending interrupt gets
 | delivered as a spurious interupt and then the state is clear.
 |
 | While that CPU0 hotplug test case is surely an esoteric issue, the APIC
 | emulation is still wrong, Even if the play_dead() code would not enable
 | interrupts then the pending IRR bit would turn into an ISR .. interrupt
 | when the APIC is reenabled on startup.

From SDM 10.4.7.2 Local APIC State After It Has Been Software Disabled
* Pending interrupts in the IRR and ISR registers are held and require
  masking or handling by the CPU.

In Thomas's testing, hardware cpu will not respect soft disable LAPIC
when IRR has already been set or APICv posted-interrupt is in flight,
so we can skip soft disable APIC checking when clearing IRR and set ISR,
continue to respect soft disable APIC when attempting to set IRR.

Reported-by: Rong Chen 
Reported-by: Feng Tang 
Reported-by: Thomas Gleixner 
Tested-by: Thomas Gleixner 
Cc: Paolo Bonzini 
Cc: Radim Krčmář 
Cc: Thomas Gleixner 
Cc: Rong Chen 
Cc: Feng Tang 
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

arm64, vdso: Define vdso_{start,end} as array

2019-07-10T07:55:46+00:00

Commit dbbb08f500d6146398b794fdc68a8e811366b451 upstream.

Adjust vdso_{start|end} to be char arrays to avoid compile-time analysis
that flags "too large" memcmp() calls with CONFIG_FORTIFY_SOURCE.

Cc: Jisheng Zhang 
Acked-by: Catalin Marinas 
Suggested-by: Mark Rutland 
Signed-off-by: Kees Cook 
Signed-off-by: Will Deacon 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Sasha Levin

tty: rocket: fix incorrect forward declaration of 'rp_init()'

2019-07-10T07:55:46+00:00

[ Upstream commit 423ea3255424b954947d167681b71ded1b8fca53 ]

Make the forward declaration actually match the real function
definition, something that previous versions of gcc had just ignored.

This is another patch to fix new warnings from gcc-9 before I start the
merge window pulls.  I don't want to miss legitimate new warnings just
because my system update brought a new compiler with new warnings.

Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

btrfs: Ensure replaced device doesn't have pending chunk allocation

2019-07-10T07:55:46+00:00

commit debd1c065d2037919a7da67baf55cc683fee09f0 upstream.

Recent FITRIM work, namely bbbf7243d62d ("btrfs: combine device update
operations during transaction commit") combined the way certain
operations are recoded in a transaction. As a result an ASSERT was added
in dev_replace_finish to ensure the new code works correctly.
Unfortunately I got reports that it's possible to trigger the assert,
meaning that during a device replace it's possible to have an unfinished
chunk allocation on the source device.

This is supposed to be prevented by the fact that a transaction is
committed before finishing the replace oepration and alter acquiring the
chunk mutex. This is not sufficient since by the time the transaction is
committed and the chunk mutex acquired it's possible to allocate a chunk
depending on the workload being executed on the replaced device. This
bug has been present ever since device replace was introduced but there
was never code which checks for it.

The correct way to fix is to ensure that there is no pending device
modification operation when the chunk mutex is acquire and if there is
repeat transaction commit. Unfortunately it's not possible to just
exclude the source device from btrfs_fs_devices::dev_alloc_list since
this causes ENOSPC to be hit in transaction commit.

Fixing that in another way would need to add special cases to handle the
last writes and forbid new ones. The looped transaction fix is more
obvious, and can be easily backported. The runtime of dev-replace is
long so there's no noticeable delay caused by that.

Reported-by: David Sterba
Fixes: 391cd9df81ac ("Btrfs: fix unprotected alloc list insertion during the finishing procedure of replace")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Nikolay Borisov
Reviewed-by: David Sterba
Signed-off-by: David Sterba
Signed-off-by: Greg Kroah-Hartman

drm/imx: only send event on crtc disable if kept disabled

2019-07-10T07:55:46+00:00

commit 5aeab2bfc9ffa72d3ca73416635cb3785dfc076f upstream.

The event will be sent as part of the vblank enable during the modeset
if the crtc is not being kept disabled.

Fixes: 5f2f911578fb ("drm/imx: atomic phase 3 step 1: Use atomic configuration")

Signed-off-by: Robert Beckett 
Reviewed-by: Daniel Vetter 
Signed-off-by: Philipp Zabel 
Signed-off-by: Greg Kroah-Hartman