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  1. 01 12月, 2019 4 次提交
  3. 24 11月, 2019 2 次提交
  5. 21 11月, 2019 3 次提交
    • N
      powerpc/pseries: Disable CPU hotplug across migrations · e7b37640
      由 Nathan Fontenot 提交于 
      [ Upstream commit 85a88cabad57d26d826dd94ea34d3a785824d802 ]

When performing partition migrations all present CPUs must be online
as all present CPUs must make the H_JOIN call as part of the migration
process. Once all present CPUs make the H_JOIN call, one CPU is returned
to make the rtas call to perform the migration to the destination system.

During testing of migration and changing the SMT state we have found
instances where CPUs are offlined, as part of the SMT state change,
before they make the H_JOIN call. This results in a hung system where
every CPU is either in H_JOIN or offline.

To prevent this this patch disables CPU hotplug during the migration
process.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      e7b37640
    • B
      powerpc/iommu: Avoid derefence before pointer check · 089b169c
      由 Breno Leitao 提交于 
      [ Upstream commit 984ecdd68de0fa1f63ce205d6c19ef5a7bc67b40 ]

The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check
if it is not NULL.

Just moving the dereference code to after the check, where there will
be guarantee that 'tbl' will not be NULL.
Signed-off-by: NBreno Leitao <leitao@debian.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      089b169c
    • A
      powerpc/vdso: Correct call frame information · e70ccd8a
      由 Alan Modra 提交于 
      [ Upstream commit 56d20861c027498b5a1112b4f9f05b56d906fdda ]

Call Frame Information is used by gdb for back-traces and inserting
breakpoints on function return for the "finish" command.  This failed
when inside __kernel_clock_gettime.  More concerning than difficulty
debugging is that CFI is also used by stack frame unwinding code to
implement exceptions.  If you have an app that needs to handle
asynchronous exceptions for some reason, and you are unlucky enough to
get one inside the VDSO time functions, your app will crash.

What's wrong:  There is control flow in __kernel_clock_gettime that
reaches label 99 without saving lr in r12.  CFI info however is
interpreted by the unwinder without reference to control flow: It's a
simple matter of "Execute all the CFI opcodes up to the current
address".  That means the unwinder thinks r12 contains the return
address at label 99.  Disabuse it of that notion by resetting CFI for
the return address at label 99.

Note that the ".cfi_restore lr" could have gone anywhere from the
"mtlr r12" a few instructions earlier to the instruction at label 99.
I put the CFI as late as possible, because in general that's best
practice (and if possible grouped with other CFI in order to reduce
the number of CFI opcodes executed when unwinding).  Using r12 as the
return address is perfectly fine after the "mtlr r12" since r12 on
that code path still contains the return address.

__get_datapage also has a CFI error.  That function temporarily saves
lr in r0, and reflects that fact with ".cfi_register lr,r0".  A later
use of r0 means the CFI at that point isn't correct, as r0 no longer
contains the return address.  Fix that too.
Signed-off-by: NAlan Modra <amodra@gmail.com>
Tested-by: NReza Arbab <arbab@linux.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      e70ccd8a
  7. 10 11月, 2019 1 次提交
  9. 12 10月, 2019 4 次提交
  11. 08 10月, 2019 4 次提交
  13. 16 9月, 2019 5 次提交
    • G
      powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts · 569775bd
      由 Gustavo Romero 提交于 
      [ Upstream commit a8318c13e79badb92bc6640704a64cc022a6eb97 ]

When in userspace and MSR FP=0 the hardware FP state is unrelated to
the current process. This is extended for transactions where if tbegin
is run with FP=0, the hardware checkpoint FP state will also be
unrelated to the current process. Due to this, we need to ensure this
hardware checkpoint is updated with the correct state before we enable
FP for this process.

Unfortunately we get this wrong when returning to a process from a
hardware interrupt. A process that starts a transaction with FP=0 can
take an interrupt. When the kernel returns back to that process, we
change to FP=1 but with hardware checkpoint FP state not updated. If
this transaction is then rolled back, the FP registers now contain the
wrong state.

The process looks like this:
   Userspace:                      Kernel

               Start userspace
                with MSR FP=0 TM=1
                  < -----
   ...
   tbegin
   bne
               Hardware interrupt
                   ---- >
                                    <do_IRQ...>
                                    ....
                                    ret_from_except
                                      restore_math()
				        /* sees FP=0 */
                                        restore_fp()
                                          tm_active_with_fp()
					    /* sees FP=1 (Incorrect) */
                                          load_fp_state()
                                        FP = 0 -> 1
                  < -----
               Return to userspace
                 with MSR TM=1 FP=1
                 with junk in the FP TM checkpoint
   TM rollback
   reads FP junk

When returning from the hardware exception, tm_active_with_fp() is
incorrectly making restore_fp() call load_fp_state() which is setting
FP=1.

The fix is to remove tm_active_with_fp().

tm_active_with_fp() is attempting to handle the case where FP state
has been changed inside a transaction. In this case the checkpointed
and transactional FP state is different and hence we must restore the
FP state (ie. we can't do lazy FP restore inside a transaction that's
used FP). It's safe to remove tm_active_with_fp() as this case is
handled by restore_tm_state(). restore_tm_state() detects if FP has
been using inside a transaction and will set load_fp and call
restore_math() to ensure the FP state (checkpoint and transaction) is
restored.

This is a data integrity problem for the current process as the FP
registers are corrupted. It's also a security problem as the FP
registers from one process may be leaked to another.

Similarly for VMX.

A simple testcase to replicate this will be posted to
tools/testing/selftests/powerpc/tm/tm-poison.c

This fixes CVE-2019-15031.

Fixes: a7771176 ("powerpc: Don't enable FP/Altivec if not checkpointed")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: NGustavo Romero <gromero@linux.ibm.com>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904045529.23002-2-gromero@linux.vnet.ibm.comSigned-off-by: NSasha Levin <sashal@kernel.org>
      569775bd
    • B
      powerpc/tm: Remove msr_tm_active() · 052bc385
      由 Breno Leitao 提交于 
      [ Upstream commit 5c784c8414fba11b62e12439f11e109fb5751f38 ]

Currently msr_tm_active() is a wrapper around MSR_TM_ACTIVE() if
CONFIG_PPC_TRANSACTIONAL_MEM is set, or it is just a function that
returns false if CONFIG_PPC_TRANSACTIONAL_MEM is not set.

This function is not necessary, since MSR_TM_ACTIVE() just do the same and
could be used, removing the dualism and simplifying the code.

This patchset remove every instance of msr_tm_active() and replaced it
by MSR_TM_ACTIVE().
Signed-off-by: NBreno Leitao <leitao@debian.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      052bc385
    • P
      KVM: PPC: Use ccr field in pt_regs struct embedded in vcpu struct · 3ac71806
      由 Paul Mackerras 提交于 
      [ Upstream commit fd0944baad806dfb4c777124ec712c55b714ff51 ]

When the 'regs' field was added to struct kvm_vcpu_arch, the code
was changed to use several of the fields inside regs (e.g., gpr, lr,
etc.) but not the ccr field, because the ccr field in struct pt_regs
is 64 bits on 64-bit platforms, but the cr field in kvm_vcpu_arch is
only 32 bits.  This changes the code to use the regs.ccr field
instead of cr, and changes the assembly code on 64-bit platforms to
use 64-bit loads and stores instead of 32-bit ones.
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      3ac71806
    • C
      powerpc/64: mark start_here_multiplatform as __ref · 7f8b2360
      由 Christophe Leroy 提交于 
      [ Upstream commit 9c4e4c90ec24652921e31e9551fcaedc26eec86d ]

Otherwise, the following warning is encountered:

WARNING: vmlinux.o(.text+0x3dc6): Section mismatch in reference from the variable start_here_multiplatform to the function .init.text:.early_setup()
The function start_here_multiplatform() references
the function __init .early_setup().
This is often because start_here_multiplatform lacks a __init
annotation or the annotation of .early_setup is wrong.

Fixes: 56c46bba9bbf ("powerpc/64: Fix booting large kernels with STRICT_KERNEL_RWX")
Cc: Russell Currey <ruscur@russell.cc>
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      7f8b2360
    • G
      powerpc/tm: Fix FP/VMX unavailable exceptions inside a transaction · 47a0f70d
      由 Gustavo Romero 提交于 
      commit 8205d5d98ef7f155de211f5e2eb6ca03d95a5a60 upstream.

When we take an FP unavailable exception in a transaction we have to
account for the hardware FP TM checkpointed registers being
incorrect. In this case for this process we know the current and
checkpointed FP registers must be the same (since FP wasn't used
inside the transaction) hence in the thread_struct we copy the current
FP registers to the checkpointed ones.

This copy is done in tm_reclaim_thread(). We use thread->ckpt_regs.msr
to determine if FP was on when in userspace. thread->ckpt_regs.msr
represents the state of the MSR when exiting userspace. This is setup
by check_if_tm_restore_required().

Unfortunatley there is an optimisation in giveup_all() which returns
early if tsk->thread.regs->msr (via local variable `usermsr`) has
FP=VEC=VSX=SPE=0. This optimisation means that
check_if_tm_restore_required() is not called and hence
thread->ckpt_regs.msr is not updated and will contain an old value.

This can happen if due to load_fp=255 we start a userspace process
with MSR FP=1 and then we are context switched out. In this case
thread->ckpt_regs.msr will contain FP=1. If that same process is then
context switched in and load_fp overflows, MSR will have FP=0. If that
process now enters a transaction and does an FP instruction, the FP
unavailable will not update thread->ckpt_regs.msr (the bug) and MSR
FP=1 will be retained in thread->ckpt_regs.msr.  tm_reclaim_thread()
will then not perform the required memcpy and the checkpointed FP regs
in the thread struct will contain the wrong values.

The code path for this happening is:

       Userspace:                      Kernel
                   Start userspace
                    with MSR FP/VEC/VSX/SPE=0 TM=1
                      < -----
       ...
       tbegin
       bne
       fp instruction
                   FP unavailable
                       ---- >
                                        fp_unavailable_tm()
					  tm_reclaim_current()
					    tm_reclaim_thread()
					      giveup_all()
					        return early since FP/VMX/VSX=0
						/* ckpt MSR not updated (Incorrect) */
					      tm_reclaim()
					        /* thread_struct ckpt FP regs contain junk (OK) */
                                              /* Sees ckpt MSR FP=1 (Incorrect) */
					      no memcpy() performed
					        /* thread_struct ckpt FP regs not fixed (Incorrect) */
					  tm_recheckpoint()
					     /* Put junk in hardware checkpoint FP regs */
                                         ....
                      < -----
                   Return to userspace
                     with MSR TM=1 FP=1
                     with junk in the FP TM checkpoint
       TM rollback
       reads FP junk

This is a data integrity problem for the current process as the FP
registers are corrupted. It's also a security problem as the FP
registers from one process may be leaked to another.

This patch moves up check_if_tm_restore_required() in giveup_all() to
ensure thread->ckpt_regs.msr is updated correctly.

A simple testcase to replicate this will be posted to
tools/testing/selftests/powerpc/tm/tm-poison.c

Similarly for VMX.

This fixes CVE-2019-15030.

Fixes: f48e91e8 ("powerpc/tm: Fix FP and VMX register corruption")
Cc: stable@vger.kernel.org # 4.12+
Signed-off-by: NGustavo Romero <gromero@linux.vnet.ibm.com>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904045529.23002-1-gromero@linux.vnet.ibm.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      47a0f70d
  15. 29 8月, 2019 1 次提交
  17. 31 7月, 2019 3 次提交
    • M
      powerpc/tm: Fix oops on sigreturn on systems without TM · b993a66d
      由 Michael Neuling 提交于 
      commit f16d80b75a096c52354c6e0a574993f3b0dfbdfe upstream.

On systems like P9 powernv where we have no TM (or P8 booted with
ppc_tm=off), userspace can construct a signal context which still has
the MSR TS bits set. The kernel tries to restore this context which
results in the following crash:

  Unexpected TM Bad Thing exception at c0000000000022fc (msr 0x8000000102a03031) tm_scratch=800000020280f033
  Oops: Unrecoverable exception, sig: 6 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 0 PID: 1636 Comm: sigfuz Not tainted 5.2.0-11043-g0a8ad0ffa4 #69
  NIP:  c0000000000022fc LR: 00007fffb2d67e48 CTR: 0000000000000000
  REGS: c00000003fffbd70 TRAP: 0700   Not tainted  (5.2.0-11045-g7142b497d8)
  MSR:  8000000102a03031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[E]>  CR: 42004242  XER: 00000000
  CFAR: c0000000000022e0 IRQMASK: 0
  GPR00: 0000000000000072 00007fffb2b6e560 00007fffb2d87f00 0000000000000669
  GPR04: 00007fffb2b6e728 0000000000000000 0000000000000000 00007fffb2b6f2a8
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR12: 0000000000000000 00007fffb2b76900 0000000000000000 0000000000000000
  GPR16: 00007fffb2370000 00007fffb2d84390 00007fffea3a15ac 000001000a250420
  GPR20: 00007fffb2b6f260 0000000010001770 0000000000000000 0000000000000000
  GPR24: 00007fffb2d843a0 00007fffea3a14a0 0000000000010000 0000000000800000
  GPR28: 00007fffea3a14d8 00000000003d0f00 0000000000000000 00007fffb2b6e728
  NIP [c0000000000022fc] rfi_flush_fallback+0x7c/0x80
  LR [00007fffb2d67e48] 0x7fffb2d67e48
  Call Trace:
  Instruction dump:
  e96a0220 e96a02a8 e96a0330 e96a03b8 394a0400 4200ffdc 7d2903a6 e92d0c00
  e94d0c08 e96d0c10 e82d0c18 7db242a6 <4c000024> 7db243a6 7db142a6 f82d0c18

The problem is the signal code assumes TM is enabled when
CONFIG_PPC_TRANSACTIONAL_MEM is enabled. This may not be the case as
with P9 powernv or if `ppc_tm=off` is used on P8.

This means any local user can crash the system.

Fix the problem by returning a bad stack frame to the user if they try
to set the MSR TS bits with sigreturn() on systems where TM is not
supported.

Found with sigfuz kernel selftest on P9.

This fixes CVE-2019-13648.

Fixes: 2b0a576d ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9
Reported-by: NPraveen Pandey <Praveen.Pandey@in.ibm.com>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190719050502.405-1-mikey@neuling.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b993a66d
    • O
      powerpc/eeh: Handle hugepages in ioremap space · 7f775a67
      由 Oliver O'Halloran 提交于 
      [ Upstream commit 33439620680be5225c1b8806579a291e0d761ca0 ]

In commit 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap
space") support for using hugepages in the vmalloc and ioremap areas was
enabled for radix. Unfortunately this broke EEH MMIO error checking.

Detection works by inserting a hook which checks the results of the
ioreadXX() set of functions.  When a read returns a 0xFFs response we
need to check for an error which we do by mapping the (virtual) MMIO
address back to a physical address, then mapping physical address to a
PCI device via an interval tree.

When translating virt -> phys we currently assume the ioremap space is
only populated by PAGE_SIZE mappings. If a hugepage mapping is found we
emit a WARN_ON(), but otherwise handles the check as though a normal
page was found. In pathalogical cases such as copying a buffer
containing a lot of 0xFFs from BAR memory this can result in the system
not booting because it's too busy printing WARN_ON()s.

There's no real reason to assume huge pages can't be present and we're
prefectly capable of handling them, so do that.

Fixes: 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap space")
Reported-by: NSachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Tested-by: NSachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190710150517.27114-1-oohall@gmail.comSigned-off-by: NSasha Levin <sashal@kernel.org>
      7f775a67
    • A
      powerpc/pci/of: Fix OF flags parsing for 64bit BARs · 216462fa
      由 Alexey Kardashevskiy 提交于 
      [ Upstream commit df5be5be8735ef2ae80d5ae1f2453cd81a035c4b ]

When the firmware does PCI BAR resource allocation, it passes the assigned
addresses and flags (prefetch/64bit/...) via the "reg" property of
a PCI device device tree node so the kernel does not need to do
resource allocation.

The flags are stored in resource::flags - the lower byte stores
PCI_BASE_ADDRESS_SPACE/etc bits and the other bytes are IORESOURCE_IO/etc.
Some flags from PCI_BASE_ADDRESS_xxx and IORESOURCE_xxx are duplicated,
such as PCI_BASE_ADDRESS_MEM_PREFETCH/PCI_BASE_ADDRESS_MEM_TYPE_64/etc.
When parsing the "reg" property, we copy the prefetch flag but we skip
on PCI_BASE_ADDRESS_MEM_TYPE_64 which leaves the flags out of sync.

The missing IORESOURCE_MEM_64 flag comes into play under 2 conditions:
1. we remove PCI_PROBE_ONLY for pseries (by hacking pSeries_setup_arch()
or by passing "/chosen/linux,pci-probe-only");
2. we request resource alignment (by passing pci=resource_alignment=
via the kernel cmd line to request PAGE_SIZE alignment or defining
ppc_md.pcibios_default_alignment which returns anything but 0). Note that
the alignment requests are ignored if PCI_PROBE_ONLY is enabled.

With 1) and 2), the generic PCI code in the kernel unconditionally
decides to:
- reassign the BARs in pci_specified_resource_alignment() (works fine)
- write new BARs to the device - this fails for 64bit BARs as the generic
code looks at IORESOURCE_MEM_64 (not set) and writes only lower 32bits
of the BAR and leaves the upper 32bit unmodified which breaks BAR mapping
in the hypervisor.

This fixes the issue by copying the flag. This is useful if we want to
enforce certain BAR alignment per platform as handling subpage sized BARs
is proven to cause problems with hotplug (SLOF already aligns BARs to 64k).
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NShawn Anastasio <shawn@anastas.io>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      216462fa
  19. 26 7月, 2019 2 次提交
    • R
      powerpc/watchpoint: Restore NV GPRs while returning from exception · 1e3b61cb
      由 Ravi Bangoria 提交于 
      commit f474c28fbcbe42faca4eb415172c07d76adcb819 upstream.

powerpc hardware triggers watchpoint before executing the instruction.
To make trigger-after-execute behavior, kernel emulates the
instruction. If the instruction is 'load something into non-volatile
register', exception handler should restore emulated register state
while returning back, otherwise there will be register state
corruption. eg, adding a watchpoint on a list can corrput the list:

  # cat /proc/kallsyms | grep kthread_create_list
  c00000000121c8b8 d kthread_create_list

Add watchpoint on kthread_create_list->prev:

  # perf record -e mem:0xc00000000121c8c0

Run some workload such that new kthread gets invoked. eg, I just
logged out from console:

  list_add corruption. next->prev should be prev (c000000001214e00), \
	but was c00000000121c8b8. (next=c00000000121c8b8).
  WARNING: CPU: 59 PID: 309 at lib/list_debug.c:25 __list_add_valid+0xb4/0xc0
  CPU: 59 PID: 309 Comm: kworker/59:0 Kdump: loaded Not tainted 5.1.0-rc7+ #69
  ...
  NIP __list_add_valid+0xb4/0xc0
  LR __list_add_valid+0xb0/0xc0
  Call Trace:
  __list_add_valid+0xb0/0xc0 (unreliable)
  __kthread_create_on_node+0xe0/0x260
  kthread_create_on_node+0x34/0x50
  create_worker+0xe8/0x260
  worker_thread+0x444/0x560
  kthread+0x160/0x1a0
  ret_from_kernel_thread+0x5c/0x70

List corruption happened because it uses 'load into non-volatile
register' instruction:

Snippet from __kthread_create_on_node:

  c000000000136be8:     addis   r29,r2,-19
  c000000000136bec:     ld      r29,31424(r29)
        if (!__list_add_valid(new, prev, next))
  c000000000136bf0:     mr      r3,r30
  c000000000136bf4:     mr      r5,r28
  c000000000136bf8:     mr      r4,r29
  c000000000136bfc:     bl      c00000000059a2f8 <__list_add_valid+0x8>

Register state from WARN_ON():

  GPR00: c00000000059a3a0 c000007ff23afb50 c000000001344e00 0000000000000075
  GPR04: 0000000000000000 0000000000000000 0000001852af8bc1 0000000000000000
  GPR08: 0000000000000001 0000000000000007 0000000000000006 00000000000004aa
  GPR12: 0000000000000000 c000007ffffeb080 c000000000137038 c000005ff62aaa00
  GPR16: 0000000000000000 0000000000000000 c000007fffbe7600 c000007fffbe7370
  GPR20: c000007fffbe7320 c000007fffbe7300 c000000001373a00 0000000000000000
  GPR24: fffffffffffffef7 c00000000012e320 c000007ff23afcb0 c000000000cb8628
  GPR28: c00000000121c8b8 c000000001214e00 c000007fef5b17e8 c000007fef5b17c0

Watchpoint hit at 0xc000000000136bec.

  addis   r29,r2,-19
   => r29 = 0xc000000001344e00 + (-19 << 16)
   => r29 = 0xc000000001214e00

  ld      r29,31424(r29)
   => r29 = *(0xc000000001214e00 + 31424)
   => r29 = *(0xc00000000121c8c0)

0xc00000000121c8c0 is where we placed a watchpoint and thus this
instruction was emulated by emulate_step. But because handle_dabr_fault
did not restore emulated register state, r29 still contains stale
value in above register state.

Fixes: 5aae8a53 ("powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors")
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1e3b61cb
    • C
      powerpc/32s: fix suspend/resume when IBATs 4-7 are used · 237ac0d7
      由 Christophe Leroy 提交于 
      commit 6ecb78ef56e08d2119d337ae23cb951a640dc52d upstream.

Previously, only IBAT1 and IBAT2 were used to map kernel linear mem.
Since commit 63b2bc619565 ("powerpc/mm/32s: Use BATs for
STRICT_KERNEL_RWX"), we may have all 8 BATs used for mapping
kernel text. But the suspend/restore functions only save/restore
BATs 0 to 3, and clears BATs 4 to 7.

Make suspend and restore functions respectively save and reload
the 8 BATs on CPUs having MMU_FTR_USE_HIGH_BATS feature.
Reported-by: NAndreas Schwab <schwab@linux-m68k.org>
Cc: stable@vger.kernel.org
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      237ac0d7
  21. 11 6月, 2019 1 次提交
    • K
      pstore: Convert buf_lock to semaphore · d4128a1b
      由 Kees Cook 提交于 
      commit ea84b580b95521644429cc6748b6c2bf27c8b0f3 upstream.

Instead of running with interrupts disabled, use a semaphore. This should
make it easier for backends that may need to sleep (e.g. EFI) when
performing a write:

|BUG: sleeping function called from invalid context at kernel/sched/completion.c:99
|in_atomic(): 1, irqs_disabled(): 1, pid: 2236, name: sig-xstate-bum
|Preemption disabled at:
|[<ffffffff99d60512>] pstore_dump+0x72/0x330
|CPU: 26 PID: 2236 Comm: sig-xstate-bum Tainted: G      D           4.20.0-rc3 #45
|Call Trace:
| dump_stack+0x4f/0x6a
| ___might_sleep.cold.91+0xd3/0xe4
| __might_sleep+0x50/0x90
| wait_for_completion+0x32/0x130
| virt_efi_query_variable_info+0x14e/0x160
| efi_query_variable_store+0x51/0x1a0
| efivar_entry_set_safe+0xa3/0x1b0
| efi_pstore_write+0x109/0x140
| pstore_dump+0x11c/0x330
| kmsg_dump+0xa4/0xd0
| oops_exit+0x22/0x30
...
Reported-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: 21b3ddd3 ("efi: Don't use spinlocks for efi vars")
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d4128a1b
  23. 04 6月, 2019 1 次提交
  25. 31 5月, 2019 2 次提交
  27. 17 5月, 2019 4 次提交
    • R
      powerpc/powernv/idle: Restore IAMR after idle · 71b20cdb
      由 Russell Currey 提交于 
      commit a3f3072db6cad40895c585dce65e36aab997f042 upstream.

Without restoring the IAMR after idle, execution prevention on POWER9
with Radix MMU is overwritten and the kernel can freely execute
userspace without faulting.

This is necessary when returning from any stop state that modifies
user state, as well as hypervisor state.

To test how this fails without this patch, load the lkdtm driver and
do the following:

  $ echo EXEC_USERSPACE > /sys/kernel/debug/provoke-crash/DIRECT

which won't fault, then boot the kernel with powersave=off, where it
will fault. Applying this patch will fix this.

Fixes: 3b10d009 ("powerpc/mm/radix: Prevent kernel execution of user space")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: NRussell Currey <ruscur@russell.cc>
Reviewed-by: NAkshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Reviewed-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      71b20cdb
    • B
      powerpc/64s: Include cpu header · 0dc9ad4e
      由 Breno Leitao 提交于 
      commit 42e2acde1237878462b028f5a27d9cc5bea7502c upstream.

Current powerpc security.c file is defining functions, as
cpu_show_meltdown(), cpu_show_spectre_v{1,2} and others, that are being
declared at linux/cpu.h header without including the header file that
contains these declarations.

This is being reported by sparse, which thinks that these functions are
static, due to the lack of declaration:

	arch/powerpc/kernel/security.c:105:9: warning: symbol 'cpu_show_meltdown' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:139:9: warning: symbol 'cpu_show_spectre_v1' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:161:9: warning: symbol 'cpu_show_spectre_v2' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:209:6: warning: symbol 'stf_barrier' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:289:9: warning: symbol 'cpu_show_spec_store_bypass' was not declared. Should it be static?

This patch simply includes the proper header (linux/cpu.h) to match
function definition and declaration.
Signed-off-by: NBreno Leitao <leitao@debian.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Major Hayden <major@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0dc9ad4e
    • N
      powerpc/smp: Fix NMI IPI xmon timeout · 19f4f94f
      由 Nicholas Piggin 提交于 
      [ Upstream commit 88b9a3d1425a436e95c41f09986fdae2daee437a ]

The xmon debugger IPI handler waits in the callback function while
xmon is still active. This means they don't complete the IPI, and the
initiator always times out waiting for them.

Things manage to work after the timeout because there is some fallback
logic to keep NMI IPI state sane in case of the timeout, but this is a
bit ugly.

This patch changes NMI IPI back to half-asynchronous (i.e., wait for
everyone to call in, do not wait for IPI function to complete), but
the complexity is avoided by going one step further and allowing new
IPIs to be issued before the IPI functions to all complete.

If synchronization against that is required, it is left up to the
caller, but current callers don't require that. In fact with the
timeout handling, callers must be able to cope with this already.

Fixes: 5b73151f ("powerpc: NMI IPI make NMI IPIs fully sychronous")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <alexander.levin@microsoft.com>
      19f4f94f
    • N
      powerpc/smp: Fix NMI IPI timeout · f8bd34d1
      由 Nicholas Piggin 提交于 
      [ Upstream commit 1b5fc84aba170bdfe3533396ca9662ceea1609b7 ]

The NMI IPI timeout logic is broken, if __smp_send_nmi_ipi() times out
on the first condition, delay_us will be zero which will send it into
the second spin loop with no timeout so it will spin forever.

Fixes: 5b73151f ("powerpc: NMI IPI make NMI IPIs fully sychronous")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSasha Levin <alexander.levin@microsoft.com>
      f8bd34d1
  29. 15 5月, 2019 1 次提交
    • J
      powerpc/speculation: Support 'mitigations=' cmdline option · 74857f69
      由 Josh Poimboeuf 提交于 
      commit 782e69efb3dfed6e8360bc612e8c7827a901a8f9 upstream

Configure powerpc CPU runtime speculation bug mitigations in accordance
with the 'mitigations=' cmdline option.  This affects Meltdown, Spectre
v1, Spectre v2, and Speculative Store Bypass.

The default behavior is unchanged.
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: NJiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/245a606e1a42a558a310220312d9b6adb9159df6.1555085500.git.jpoimboe@redhat.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      74857f69
  31. 08 5月, 2019 1 次提交
  33. 02 5月, 2019 1 次提交