linux-toradex.git/arch/powerpc, branch v5.7-rc7

Merge tag 'powerpc-5.7-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-05-22T15:51:39+00:00

Pull powerpc fixes from Michael Ellerman:

 - a revert of a recent change to the PTE bits for 32-bit BookS, which
   broke swap.

 - a "fix" to disable STRICT_KERNEL_RWX for 64-bit in Kconfig, as it's
   causing crashes for some people.

Thanks to Christophe Leroy and Rui Salvaterra.

* tag 'powerpc-5.7-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Disable STRICT_KERNEL_RWX
  Revert "powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits."

powerpc/64s: Disable STRICT_KERNEL_RWX

2020-05-21T14:04:51+00:00

Several strange crashes have been eventually traced back to
STRICT_KERNEL_RWX and its interaction with code patching.

Various paths in our ftrace, kprobes and other patching code need to
be hardened against patching failures, otherwise we can end up running
with partially/incorrectly patched ftrace paths, kprobes or jump
labels, which can then cause strange crashes.

Although fixes for those are in development, they're not -rc material.

There also seem to be problems with the underlying strict RWX logic,
which needs further debugging.

So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from
enabling the option and tripping over the bugs.

Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au

Revert "powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits."

2020-05-20T12:35:52+00:00

This reverts commit 697ece78f8f749aeea40f2711389901f0974017a.

The implementation of SWAP on powerpc requires page protection
bits to not be one of the least significant PTE bits.

Until the SWAP implementation is changed and this requirement voids,
we have to keep at least _PAGE_RW outside of the 3 last bits.

For now, revert to previous PTE bits order. A further rework
may come later.

Fixes: 697ece78f8f7 ("powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits.")
Reported-by: Rui Salvaterra 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/b34706f8de87f84d135abb5f3ede6b6f16fb1f41.1589969799.git.christophe.leroy@csgroup.eu

Merge tag 'powerpc-5.7-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-05-16T20:34:45+00:00

Pull powerpc fixes from Michael Ellerman:

 - A fix for unrecoverable SLB faults in the interrupt exit path,
   introduced by the recent rewrite of interrupt exit in C.

 - Four fixes for our KUAP (Kernel Userspace Access Prevention) support
   on 64-bit. These are all fairly minor with the exception of the
   change to evaluate the get/put_user() arguments before we enable user
   access, which reduces the amount of code we run with user access
   enabled.

 - A fix for our secure boot IMA rules, if enforcement of module
   signatures is enabled at runtime rather than build time.

 - A fix to our 32-bit VDSO clock_getres() which wasn't falling back to
   the syscall for unknown clocks.

 - A build fix for CONFIG_PPC_KUAP_DEBUG on 32-bit BookS, and another
   for 40x.

Thanks to: Christophe Leroy, Hugh Dickins, Nicholas Piggin, Aurelien
Jarno, Mimi Zohar, Nayna Jain.

* tag 'powerpc-5.7-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/40x: Make more space for system call exception
  powerpc/vdso32: Fallback on getres syscall when clock is unknown
  powerpc/32s: Fix build failure with CONFIG_PPC_KUAP_DEBUG
  powerpc/ima: Fix secure boot rules in ima arch policy
  powerpc/64s/kuap: Restore AMR in fast_interrupt_return
  powerpc/64s/kuap: Restore AMR in system reset exception
  powerpc/64/kuap: Move kuap checks out of MSR[RI]=0 regions of exit code
  powerpc/64s: Fix unrecoverable SLB crashes due to preemption check
  powerpc/uaccess: Evaluate macro arguments once, before user access is allowed

powerpc/40x: Make more space for system call exception

2020-05-12T11:22:11+00:00

When CONFIG_VIRT_CPU_ACCOUNTING is selected, system call exception
handler doesn't fit below 0xd00 and build fails.

As exception 0xd00 doesn't exist and is never generated by 40x,
comment it out in order to get more space for system call exception.

Fixes: 9e27086292aa ("powerpc/32: Warn and return ENOSYS on syscalls from kernel")
Reported-by: kbuild test robot 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/633165d72f75b4ef4c0901aebe99d3915c93e9a2.1589043863.git.christophe.leroy@csgroup.eu

powerpc/vdso32: Fallback on getres syscall when clock is unknown

2020-05-11T09:24:29+00:00

There are other clocks than the standard ones, for instance
per process clocks. Therefore, being above the last standard clock
doesn't mean it is a bad clock. So, fallback to syscall instead
of returning -EINVAL inconditionaly.

Fixes: e33ffc956b08 ("powerpc/vdso32: implement clock_getres entirely")
Cc: stable@vger.kernel.org # v5.6+
Reported-by: Aurelien Jarno 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Tested-by: Aurelien Jarno 
Link: https://lore.kernel.org/r/7316a9e2c0c2517923eb4b0411c4a08d15e675a4.1589017281.git.christophe.leroy@csgroup.eu

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2020-05-07T16:50:59+00:00

Pull kvm fixes from Paolo Bonzini:
 "Bugfixes, mostly for ARM and AMD, and more documentation.

  Slightly bigger than usual because I couldn't send out what was
  pending for rc4, but there is nothing worrisome going on. I have more
  fixes pending for guest debugging support (gdbstub) but I will send
  them next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
  KVM: X86: Declare KVM_CAP_SET_GUEST_DEBUG properly
  KVM: selftests: Fix build for evmcs.h
  kvm: x86: Use KVM CPU capabilities to determine CR4 reserved bits
  KVM: VMX: Explicitly clear RFLAGS.CF and RFLAGS.ZF in VM-Exit RSB path
  docs/virt/kvm: Document configuring and running nested guests
  KVM: s390: Remove false WARN_ON_ONCE for the PQAP instruction
  kvm: ioapic: Restrict lazy EOI update to edge-triggered interrupts
  KVM: x86: Fixes posted interrupt check for IRQs delivery modes
  KVM: SVM: fill in kvm_run->debug.arch.dr[67]
  KVM: nVMX: Replace a BUG_ON(1) with BUG() to squash clang warning
  KVM: arm64: Fix 32bit PC wrap-around
  KVM: arm64: vgic-v4: Initialize GICv4.1 even in the absence of a virtual ITS
  KVM: arm64: Save/restore sp_el0 as part of __guest_enter
  KVM: arm64: Delete duplicated label in invalid_vector
  KVM: arm64: vgic-its: Fix memory leak on the error path of vgic_add_lpi()
  KVM: arm64: vgic-v3: Retire all pending LPIs on vcpu destroy
  KVM: arm: vgic-v2: Only use the virtual state when userspace accesses pending bits
  KVM: arm: vgic: Only use the virtual state when userspace accesses enable bits
  KVM: arm: vgic: Synchronize the whole guest on GIC{D,R}_I{S,C}ACTIVER read
  KVM: arm64: PSCI: Forbid 64bit functions for 32bit guests
  ...

powerpc/32s: Fix build failure with CONFIG_PPC_KUAP_DEBUG

2020-05-07T07:25:54+00:00

gpr2 is not a parametre of kuap_check(), it doesn't exist.

Use gpr instead.

Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/ea599546f2a7771bde551393889e44e6b2632332.1587368807.git.christophe.leroy@c-s.fr

powerpc/ima: Fix secure boot rules in ima arch policy

2020-05-07T07:25:54+00:00

To prevent verifying the kernel module appended signature
twice (finit_module), once by the module_sig_check() and again by IMA,
powerpc secure boot rules define an IMA architecture specific policy
rule only if CONFIG_MODULE_SIG_FORCE is not enabled. This,
unfortunately, does not take into account the ability of enabling
"sig_enforce" on the boot command line (module.sig_enforce=1).

Including the IMA module appraise rule results in failing the
finit_module syscall, unless the module signing public key is loaded
onto the IMA keyring.

This patch fixes secure boot policy rules to be based on
CONFIG_MODULE_SIG instead.

Fixes: 4238fad366a6 ("powerpc/ima: Add support to initialize ima policy rules")
Signed-off-by: Nayna Jain 
Signed-off-by: Michael Ellerman 
Signed-off-by: Mimi Zohar 
Link: https://lore.kernel.org/r/1588342612-14532-1-git-send-email-nayna@linux.ibm.com

powerpc/64s/kuap: Restore AMR in fast_interrupt_return

2020-05-07T01:00:41+00:00

Interrupts that use fast_interrupt_return actually do lock AMR, but
they have been ones which tend to come from userspace (or kernel bugs)
in radix mode. With kuap on hash, segment interrupts are taken in
kernel often, which quickly breaks due to the missing restore.

Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200429065654.1677541-6-npiggin@gmail.com