linux-toradex.git/arch, branch v4.9.82

mn10300/misalignment: Use SIGSEGV SEGV_MAPERR to report a failed user copy

2018-02-17T12:21:20+00:00

commit 6ac1dc736b323011a55ecd1fc5897c24c4f77cbd upstream.

Setting si_code to 0 is the same a setting si_code to SI_USER which is definitely
not correct.  With si_code set to SI_USER si_pid and si_uid will be copied to
userspace instead of si_addr.  Which is very wrong.

So fix this by using a sensible si_code (SEGV_MAPERR) for this failure.

Fixes: b920de1b77b7 ("mn10300: add the MN10300/AM33 architecture to the kernel")
Cc: David Howells 
Cc: Masakazu Urade 
Cc: Koichi Yasutake 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

xtensa: fix futex_atomic_cmpxchg_inatomic

2018-02-17T12:21:19+00:00

commit ca47480921587ae30417dd234a9f79af188e3666 upstream.

Return 0 if the operation was successful, not the userspace memory
value. Check that userspace value equals passed oldval, not itself.
Don't update *uval if the value wasn't read from userspace memory.

This fixes process hang due to infinite loop in futex_lock_pi.
It also fixes a bunch of glibc tests nptl/tst-mutexpi*.

Signed-off-by: Max Filippov 
Signed-off-by: Greg Kroah-Hartman

alpha: fix formating of stack content

2018-02-17T12:21:19+00:00

commit 4b01abdb32fc36abe877503bfbd33019159fad71 upstream.

Since version 4.9, the kernel automatically breaks printk calls into
multiple newlines unless pr_cont is used. Fix the alpha stacktrace code,
so that it prints stack trace in four columns, as it was initially
intended.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

alpha: fix reboot on Avanti platform

2018-02-17T12:21:19+00:00

commit 55fc633c41a08ce9244ff5f528f420b16b1e04d6 upstream.

We need to define NEED_SRM_SAVE_RESTORE on the Avanti, otherwise we get
machine check exception when attempting to reboot the machine.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

alpha: fix crash if pthread_create races with signal delivery

2018-02-17T12:21:19+00:00

commit 21ffceda1c8b3807615c40d440d7815e0c85d366 upstream.

On alpha, a process will crash if it attempts to start a thread and a
signal is delivered at the same time. The crash can be reproduced with
this program: https://cygwin.com/ml/cygwin/2014-11/msg00473.html

The reason for the crash is this:
* we call the clone syscall
* we go to the function copy_process
* copy process calls copy_thread_tls, it is a wrapper around copy_thread
* copy_thread sets the tls pointer: childti->pcb.unique = regs->r20
* copy_thread sets regs->r20 to zero
* we go back to copy_process
* copy process checks "if (signal_pending(current))" and returns
  -ERESTARTNOINTR
* the clone syscall is restarted, but this time, regs->r20 is zero, so
  the new thread is created with zero tls pointer
* the new thread crashes in start_thread when attempting to access tls

The comment in the code says that setting the register r20 is some
compatibility with OSF/1. But OSF/1 doesn't use the CLONE_SETTLS flag, so
we don't have to zero r20 if CLONE_SETTLS is set. This patch fixes the bug
by zeroing regs->r20 only if CLONE_SETTLS is not set.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

signal/sh: Ensure si_signo is initialized in do_divide_error

2018-02-17T12:21:19+00:00

commit 0e88bb002a9b2ee8cc3cc9478ce2dc126f849696 upstream.

Set si_signo.

Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: Paul Mundt 
Cc: linux-sh@vger.kernel.org
Fixes: 0983b31849bb ("sh: Wire up division and address error exceptions on SH-2A.")
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

signal/openrisc: Fix do_unaligned_access to send the proper signal

2018-02-17T12:21:19+00:00

commit 500d58300571b6602341b041f97c082a461ef994 upstream.

While reviewing the signal sending on openrisc the do_unaligned_access
function stood out because it is obviously wrong.  A comment about an
si_code set above when actually si_code is never set.  Leading to a
random si_code being sent to userspace in the event of an unaligned
access.

Looking further SIGBUS BUS_ADRALN is the proper pair of signal and
si_code to send for an unaligned access. That is what other
architectures do and what is required by posix.

Given that do_unaligned_access is broken in a way that no one can be
relying on it on openrisc fix the code to just do the right thing.

Fixes: 769a8a96229e ("OpenRISC: Traps")
Cc: Jonas Bonn 
Cc: Stefan Kristiansson 
Cc: Stafford Horne 
Cc: Arnd Bergmann 
Cc: openrisc@lists.librecores.org
Acked-by: Stafford Horne 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

KVM: arm/arm64: Handle CPU_PM_ENTER_FAILED

2018-02-17T12:21:17+00:00

commit 58d6b15e9da5042a99c9c30ad725792e4569150e upstream.

cpu_pm_enter() calls the pm notifier chain with CPU_PM_ENTER, then if
there is a failure: CPU_PM_ENTER_FAILED.

When KVM receives CPU_PM_ENTER it calls cpu_hyp_reset() which will
return us to the hyp-stub. If we subsequently get a CPU_PM_ENTER_FAILED,
KVM does nothing, leaving the CPU running with the hyp-stub, at odds
with kvm_arm_hardware_enabled.

Add CPU_PM_ENTER_FAILED as a fallthrough for CPU_PM_EXIT, this reloads
KVM based on kvm_arm_hardware_enabled. This is safe even if CPU_PM_ENTER
never gets as far as KVM, as cpu_hyp_reinit() calls cpu_hyp_reset()
to make sure the hyp-stub is loaded before reloading KVM.

Fixes: 67f691976662 ("arm64: kvm: allows kvm cpu hotplug")
CC: Lorenzo Pieralisi 
Reviewed-by: Christoffer Dall 
Signed-off-by: James Morse 
Signed-off-by: Christoffer Dall 
Signed-off-by: Greg Kroah-Hartman

KVM: nVMX: Fix races when sending nested PI while dest enters/leaves L2

2018-02-17T12:21:17+00:00

commit 6b6977117f50d60455ace86b2d256f6fb4f3de05 upstream.

Consider the following scenario:
1. CPU A calls vmx_deliver_nested_posted_interrupt() to send an IPI
to CPU B via virtual posted-interrupt mechanism.
2. CPU B is currently executing L2 guest.
3. vmx_deliver_nested_posted_interrupt() calls
kvm_vcpu_trigger_posted_interrupt() which will note that
vcpu->mode == IN_GUEST_MODE.
4. Assume that before CPU A sends the physical POSTED_INTR_NESTED_VECTOR
IPI, CPU B exits from L2 to L0 during event-delivery
(valid IDT-vectoring-info).
5. CPU A now sends the physical IPI. The IPI is received in host and
it's handler (smp_kvm_posted_intr_nested_ipi()) does nothing.
6. Assume that before CPU A sets pi_pending=true and KVM_REQ_EVENT,
CPU B continues to run in L0 and reach vcpu_enter_guest(). As
KVM_REQ_EVENT is not set yet, vcpu_enter_guest() will continue and resume
L2 guest.
7. At this point, CPU A sets pi_pending=true and KVM_REQ_EVENT but
it's too late! CPU B already entered L2 and KVM_REQ_EVENT will only be
consumed at next L2 entry!

Another scenario to consider:
1. CPU A calls vmx_deliver_nested_posted_interrupt() to send an IPI
to CPU B via virtual posted-interrupt mechanism.
2. Assume that before CPU A calls kvm_vcpu_trigger_posted_interrupt(),
CPU B is at L0 and is about to resume into L2. Further assume that it is
in vcpu_enter_guest() after check for KVM_REQ_EVENT.
3. At this point, CPU A calls kvm_vcpu_trigger_posted_interrupt() which
will note that vcpu->mode != IN_GUEST_MODE. Therefore, do nothing and
return false. Then, will set pi_pending=true and KVM_REQ_EVENT.
4. Now CPU B continue and resumes into L2 guest without processing
the posted-interrupt until next L2 entry!

To fix both issues, we just need to change
vmx_deliver_nested_posted_interrupt() to set pi_pending=true and
KVM_REQ_EVENT before calling kvm_vcpu_trigger_posted_interrupt().

It will fix the first scenario by chaging step (6) to note that
KVM_REQ_EVENT and pi_pending=true and therefore process
nested posted-interrupt.

It will fix the second scenario by two possible ways:
1. If kvm_vcpu_trigger_posted_interrupt() is called while CPU B has changed
vcpu->mode to IN_GUEST_MODE, physical IPI will be sent and will be received
when CPU resumes into L2.
2. If kvm_vcpu_trigger_posted_interrupt() is called while CPU B hasn't yet
changed vcpu->mode to IN_GUEST_MODE, then after CPU B will change
vcpu->mode it will call kvm_request_pending() which will return true and
therefore force another round of vcpu_enter_guest() which will note that
KVM_REQ_EVENT and pi_pending=true and therefore process nested
posted-interrupt.

Fixes: 705699a13994 ("KVM: nVMX: Enable nested posted interrupt processing")
Signed-off-by: Liran Alon 
Reviewed-by: Nikita Leshenko 
Reviewed-by: Krish Sadhukhan 
[Add kvm_vcpu_kick to also handle the case where L1 doesn't intercept L2 HLT
 and L2 executes HLT instruction. - Paolo]
Signed-off-by: Paolo Bonzini 
Signed-off-by: Radim Krčmář 
Signed-off-by: Greg Kroah-Hartman

arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls

2018-02-17T12:21:17+00:00

commit 20e8175d246e9f9deb377f2784b3e7dfb2ad3e86 upstream.

KVM doesn't follow the SMCCC when it comes to unimplemented calls,
and inject an UNDEF instead of returning an error. Since firmware
calls are now used for security mitigation, they are becoming more
common, and the undef is counter productive.

Instead, let's follow the SMCCC which states that -1 must be returned
to the caller when getting an unknown function number.

Tested-by: Ard Biesheuvel 
Signed-off-by: Marc Zyngier 
Signed-off-by: Catalin Marinas 
Signed-off-by: Greg Kroah-Hartman