linux-stable.git/arch/arm, branch v3.16.69

locking/static_keys: Add a new static_key interface

2019-05-22T22:15:05+00:00

commit 11276d5306b8e5b438a36bbff855fe792d7eaa61 upstream.

There are various problems and short-comings with the current
static_key interface:

 - static_key_{true,false}() read like a branch depending on the key
   value, instead of the actual likely/unlikely branch depending on
   init value.

 - static_key_{true,false}() are, as stated above, tied to the
   static_key init values STATIC_KEY_INIT_{TRUE,FALSE}.

 - we're limited to the 2 (out of 4) possible options that compile to
   a default NOP because that's what our arch_static_branch() assembly
   emits.

So provide a new static_key interface:

  DEFINE_STATIC_KEY_TRUE(name);
  DEFINE_STATIC_KEY_FALSE(name);

Which define a key of different types with an initial true/false
value.

Then allow:

   static_branch_likely()
   static_branch_unlikely()

to take a key of either type and emit the right instruction for the
case.

This means adding a second arch_static_branch_jump() assembly helper
which emits a JMP per default.

In order to determine the right instruction for the right state,
encode the branch type in the LSB of jump_entry::key.

This is the final step in removing the naming confusion that has led to
a stream of avoidable bugs such as:

  a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()")

... but it also allows new static key combinations that will give us
performance enhancements in the subsequent patches.

Tested-by: Rabin Vincent  # arm
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Michael Ellerman  # ppc
Acked-by: Heiko Carstens  # s390
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.16:
 - For s390, use the 31-bit-compatible macros in arch_static_branch_jump()
 - 
Signed-off-by: Ben Hutchings

jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP}

2019-05-22T22:15:03+00:00

commit 76b235c6bcb16062d663e2ee96db0b69f2e6bc14 upstream.

Since we've already stepped away from ENABLE is a JMP and DISABLE is a
NOP with the branch_default bits, and are going to make it even worse,
rename it to make it all clearer.

This way we don't mix multiple levels of logic attributes, but have a
plain 'physical' name for what the current instruction patching status
of a jump label is.

This is a first step in removing the naming confusion that has led to
a stream of avoidable bugs such as:

  a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()")

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
[ Beefed up the changelog. ]
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

jump_label: Allow asm/jump_label.h to be included in assembly

2019-05-22T22:15:02+00:00

commit 55dd0df781e58ec23d218376ea4a676e7362a98c upstream.

Wrap asm/jump_label.h for all archs with #ifndef __ASSEMBLY__.
Since these are kernel only headers, we don't need #ifdef
__KERNEL__ so can simplify things a bit.

If an architecture wants to use jump labels in assembly, it
will still need to define a macro to create the __jump_table
entries (see ARCH_STATIC_BRANCH in the powerpc asm/jump_label.h
for an example).

Signed-off-by: Anton Blanchard 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: benh@kernel.crashing.org
Cc: catalin.marinas@arm.com
Cc: davem@davemloft.net
Cc: heiko.carstens@de.ibm.com
Cc: jbaron@akamai.com
Cc: linux@arm.linux.org.uk
Cc: linuxppc-dev@lists.ozlabs.org
Cc: liuj97@gmail.com
Cc: mgorman@suse.de
Cc: mmarek@suse.cz
Cc: mpe@ellerman.id.au
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: rostedt@goodmis.org
Cc: schwidefsky@de.ibm.com
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1428551492-21977-1-git-send-email-anton@samba.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Ben Hutchings

ARM: iop32x/n2100: fix PCI IRQ mapping

2019-05-02T20:41:32+00:00

commit db4090920ba2d61a5827a23e441447926a02ffee upstream.

Booting 4.20 on a TheCUS N2100 results in a kernel oops while probing
PCI, due to n2100_pci_map_irq() having been discarded during boot.

Signed-off-by: Russell King 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Ben Hutchings

ARM: pxa: ssp: unneeded to free devm_ allocated data

2019-05-02T20:41:28+00:00

commit ba16adeb346387eb2d1ada69003588be96f098fa upstream.

devm_ allocated data will be automatically freed. The free
of devm_ allocated data is invalid.

Fixes: 1c459de1e645 ("ARM: pxa: ssp: use devm_ functions")
Signed-off-by: Peng Hao 
[title's prefix changed]
Signed-off-by: Robert Jarzmik 
Signed-off-by: Ben Hutchings

ARM: dts: kirkwood: Fix polarity of GPIO fan lines

2019-05-02T20:41:17+00:00

commit b5f034845e70916fd33e172fad5ad530a29c10ab upstream.

These two lines are active high, not active low. The bug was
found when we changed the kernel to respect the polarity defined
in the device tree.

Fixes: 1b90e06b1429 ("ARM: kirkwood: Use devicetree to define DNS-32[05] fan")
Cc: Jamie Lentin 
Cc: Guenter Roeck 
Cc: Jason Cooper 
Cc: Andrew Lunn 
Cc: Gregory Clement 
Cc: Sebastian Hesselbarth 
Cc: Julien D'Ascenzio 
Reviewed-by: Andrew Lunn 
Tested-by: Jamie Lentin 
Reported-by: Julien D'Ascenzio 
Tested-by: Julien D'Ascenzio 
Signed-off-by: Linus Walleij 
Signed-off-by: Gregory CLEMENT 
Signed-off-by: Ben Hutchings

KVM: arm/arm64: Fix VMID alloc race by reverting to lock-less

2019-04-04T15:13:57+00:00

commit fb544d1ca65a89f7a3895f7531221ceeed74ada7 upstream.

We recently addressed a VMID generation race by introducing a read/write
lock around accesses and updates to the vmid generation values.

However, kvm_arch_vcpu_ioctl_run() also calls need_new_vmid_gen() but
does so without taking the read lock.

As far as I can tell, this can lead to the same kind of race:

  VM 0, VCPU 0			VM 0, VCPU 1
  ------------			------------
  update_vttbr (vmid 254)
  				update_vttbr (vmid 1) // roll over
				read_lock(kvm_vmid_lock);
				force_vm_exit()
  local_irq_disable
  need_new_vmid_gen == false //because vmid gen matches

  enter_guest (vmid 254)
  				kvm_arch.vttbr = :
				read_unlock(kvm_vmid_lock);

  				enter_guest (vmid 1)

Which results in running two VCPUs in the same VM with different VMIDs
and (even worse) other VCPUs from other VMs could now allocate clashing
VMID 254 from the new generation as long as VCPU 0 is not exiting.

Attempt to solve this by making sure vttbr is updated before another CPU
can observe the updated VMID generation.

Fixes: f0cf47d939d0 "KVM: arm/arm64: Close VMID generation race"
Reviewed-by: Julien Thierry 
Signed-off-by: Christoffer Dall 
Signed-off-by: Marc Zyngier 
[bwh: Backported to 3.16:
 - Use ACCESS_ONCE() instead of {READ,WRITE}_ONCE()
 - Adjust filename]
Signed-off-by: Ben Hutchings

KVM: Protect device ops->create and list_add with kvm->lock

2019-03-25T17:32:35+00:00

commit a28ebea2adc4a2bef5989a5a181ec238f59fbcad upstream.

KVM devices were manipulating list data structures without any form of
synchronization, and some implementations of the create operations also
suffered from a lack of synchronization.

Now when we've split the xics create operation into create and init, we
can hold the kvm->lock mutex while calling the create operation and when
manipulating the devices list.

The error path in the generic code gets slightly ugly because we have to
take the mutex again and delete the device from the list, but holding
the mutex during anon_inode_getfd or releasing/locking the mutex in the
common non-error path seemed wrong.

Signed-off-by: Christoffer Dall 
Reviewed-by: Paolo Bonzini 
Acked-by: Christian Borntraeger 
Signed-off-by: Radim Krčmář 
[bwh: Backported to 3.16:
 - Drop change to a failure path that doesn't exist in kvm_vgic_create() 
 - Adjust filename, context]
Signed-off-by: Ben Hutchings

ARM: mmp/mmp2: fix cpu_is_mmp2() on mmp2-dt

2019-02-11T17:54:18+00:00

commit 76f4e2c3b6a560cdd7a75b87df543e04d05a9e5f upstream.

cpu_is_mmp2() was equivalent to cpu_is_pj4(), wouldn't be correct for
multiplatform kernels. Fix it by also considering mmp_chip_id, as is
done for cpu_is_pxa168() and cpu_is_pxa910() above.

Moreover, it is only available with CONFIG_CPU_MMP2 and thus doesn't work
on DT-based MMP2 machines. Enable it on CONFIG_MACH_MMP2_DT too.

Note: CONFIG_CPU_MMP2 is only used for machines that use board files
instead of DT. It should perhaps be renamed. I'm not doing it now, because
I don't have a better idea.

Signed-off-by: Lubomir Rintel 
Acked-by: Arnd Bergmann 
Signed-off-by: Olof Johansson 
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings

ARM: OMAP1: ams-delta: Fix possible use of uninitialized field

2019-02-11T17:53:54+00:00

commit cec83ff1241ec98113a19385ea9e9cfa9aa4125b upstream.

While playing with initialization order of modem device, it has been
discovered that under some circumstances (early console init, I
believe) its .pm() callback may be called before the
uart_port->private_data pointer is initialized from
plat_serial8250_port->private_data, resulting in NULL pointer
dereference.  Fix it by checking for uninitialized pointer before using
it in modem_pm().

Fixes: aabf31737a6a ("ARM: OMAP1: ams-delta: update the modem to use regulator API")
Signed-off-by: Janusz Krzysztofik 
Signed-off-by: Tony Lindgren 
Signed-off-by: Ben Hutchings