Commit graph

2160 commits

Author SHA1 Message Date
Aneesh Kumar K.V
2230ebf6e6 powerpc/mm: Handle page table allocation failures
This fixes kernel crash that arises due to not handling page table allocation
failures while allocating hugetlb page table.

Fixes: e2b3d202d1 ("powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:47:59 +10:00
Aneesh Kumar K.V
1ecf2cdc74 powerpc/mm: pmd_devmap implies pmd_large().
large devmap usage is dependent on THP. Hence once check is sufficient.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:43:59 +10:00
Aneesh Kumar K.V
d6eacedd1f powerpc/book3s: Use config independent helpers for page table walk
Even when we have HugeTLB and THP disabled, kernel linear map can still be
mapped with hugepages. This is only an issue with radix translation because hash
MMU doesn't map kernel linear range in linux page table and other kernel
map areas are not mapped using hugepage.

Add config independent helpers and put WARN_ON() when we don't expect things
to be mapped via hugepages.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:43:50 +10:00
Aneesh Kumar K.V
c0b1b23b9c powerpc/mm/nvdimm: Add an informative message if we fail to allocate altmap block
Allocation from altmap area can fail based on vmemmap page size used.
Add kernel info message to indicate the failure. That allows the user
to identify whether they are really using persistent memory reserved
space for per-page metadata.

The message looks like:
  [  136.587212] altmap block allocation failed, falling back to system memory

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:32:57 +10:00
Aneesh Kumar K.V
495c2ff4c8 powerpc/mm: Consolidate numa_enable check and min_common_depth check
If we fail to parse min_common_depth from device tree we boot with
numa disabled. Reflect the same by updating numa_enabled variable
to false. Also, switch all min_common_depth failure check to
if (!numa_enabled) check.

This helps us to avoid checking for both in different code paths.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:27:33 +10:00
Aneesh Kumar K.V
f52741c410 powerpc/mm: Fix node look up with numa=off boot
If we boot with numa=off, we need to make sure we return NUMA_NO_NODE when
looking up associativity details of resources. Without this, we hit crash
like below

BUG: Unable to handle kernel data access at 0x40000000008
Faulting instruction address: 0xc000000008f31704
cpu 0x1b: Vector: 380 (Data SLB Access) at [c00000000b9bb320]
    pc: c000000008f31704: _raw_spin_lock+0x14/0x100
    lr: c0000000083f41fc: ____cache_alloc_node+0x5c/0x290
    sp: c00000000b9bb5b0
   msr: 800000010280b033
   dar: 40000000008
  current = 0xc00000000b9a2700
  paca    = 0xc00000000a740c00   irqmask: 0x03   irq_happened: 0x01
    pid   = 1, comm = swapper/27
Linux version 5.2.0-rc4-00925-g74e188c620b1 (root@linux-d8ip) (gcc version 7.4.1 20190424 [gcc-7-branch revision 270538] (SUSE Linux)) #34 SMP Sat Jun 29 00:41:02 EDT 2019
enter ? for help
[link register   ] c0000000083f41fc ____cache_alloc_node+0x5c/0x290
[c00000000b9bb5b0] 0000000000000dc0 (unreliable)
[c00000000b9bb5f0] c0000000083f48c8 kmem_cache_alloc_node_trace+0x138/0x360
[c00000000b9bb670] c000000008aa789c devres_alloc_node+0x4c/0xa0
[c00000000b9bb6a0] c000000008337218 devm_memremap+0x58/0x130
[c00000000b9bb6f0] c000000008aed00c devm_nsio_enable+0xdc/0x170
[c00000000b9bb780] c000000008af3b6c nd_pmem_probe+0x4c/0x180
[c00000000b9bb7b0] c000000008ad84cc nvdimm_bus_probe+0xac/0x260
[c00000000b9bb840] c000000008aa0628 really_probe+0x148/0x500
[c00000000b9bb8d0] c000000008aa0d7c driver_probe_device+0x19c/0x1d0
[c00000000b9bb950] c000000008aa11bc device_driver_attach+0xcc/0x100
[c00000000b9bb990] c000000008aa12ec __driver_attach+0xfc/0x1e0
[c00000000b9bba10] c000000008a9d0a4 bus_for_each_dev+0xb4/0x130
[c00000000b9bba70] c000000008a9fc04 driver_attach+0x34/0x50
[c00000000b9bba90] c000000008a9f118 bus_add_driver+0x1d8/0x300
[c00000000b9bbb20] c000000008aa2358 driver_register+0x98/0x1a0
[c00000000b9bbb90] c000000008ad7e6c __nd_driver_register+0x5c/0x100
[c00000000b9bbbf0] c0000000093efbac nd_pmem_driver_init+0x34/0x48
[c00000000b9bbc10] c0000000080106c0 do_one_initcall+0x60/0x2d0
[c00000000b9bbce0] c00000000938463c kernel_init_freeable+0x384/0x48c
[c00000000b9bbdb0] c000000008010a5c kernel_init+0x2c/0x160
[c00000000b9bbe20] c00000000800ba54 ret_from_kernel_thread+0x5c/0x68

Reported-and-debugged-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:27:32 +10:00
Aneesh Kumar K.V
ea9f5b702f powerpc/mm/drconf: Use NUMA_NO_NODE on failures instead of node 0
If we fail to parse the associativity array we should default to
NUMA_NO_NODE instead of NODE 0. Rest of the code fallback to the
right default if we find the numa node value NUMA_NO_NODE.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:27:31 +10:00
Aneesh Kumar K.V
89a3496e06 powerpc/mm/radix: Use the right page size for vmemmap mapping
We use mmu_vmemmap_psize to find the page size for mapping the vmmemap area.
With radix translation, we are suboptimally setting this value to PAGE_SIZE.

We do check for 2M page size support and update mmu_vmemap_psize to use
hugepage size but we suboptimally reset the value to PAGE_SIZE in
radix__early_init_mmu(). This resulted in always mapping vmemmap area with
64K page size.

Fixes: 2bfd65e45e ("powerpc/mm/radix: Add radix callbacks for early init routines")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:27:21 +10:00
Aneesh Kumar K.V
78c9498885 powerpc/mm/hash/4k: Don't use 64K page size for vmemmap with 4K pagesize
With hash translation and 4K PAGE_SIZE config, we need to make sure we don't
use 64K page size for vmemmap.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-05 00:27:20 +10:00
Naveen N. Rao
d62c8deeb6 powerpc/pseries: Provide vcpu dispatch statistics
For Shared Processor LPARs, the POWER Hypervisor maintains a
relatively static mapping of the LPAR processors (vcpus) to physical
processor chips (representing the "home" node) and tries to always
dispatch vcpus on their associated physical processor chip. However,
under certain scenarios, vcpus may be dispatched on a different
processor chip (away from its home node). The actual physical
processor number on which a certain vcpu is dispatched is available to
the guest in the 'processor_id' field of each DTL entry.

The guest can discover the home node of each vcpu through the
H_HOME_NODE_ASSOCIATIVITY(flags=1) hcall. The guest can also discover
the associativity of physical processors, as represented in the DTL
entry, through the H_HOME_NODE_ASSOCIATIVITY(flags=2) hcall.

These can then be compared to determine if the vcpu was dispatched on
its home node or not. If the vcpu was not dispatched on the home node,
it is possible to determine if the vcpu was dispatched in a different
chip, socket or drawer.

Introduce a procfs file /proc/powerpc/vcpudispatch_stats that can be
used to obtain these statistics. Writing '1' to this file enables
collecting the statistics, while writing '0' disables the statistics.
The statistics themselves are available by reading the procfs file. By
default, the DTLB log for each vcpu is processed 50 times a second so
as not to miss any entries. This processing frequency can be changed
through /proc/powerpc/vcpudispatch_stats_freq.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-04 22:27:09 +10:00
Naveen N. Rao
5a1ea4774d powerpc/pseries: Move mm/book3s64/vphn.c under platforms/pseries/
hcall_vphn() is specific to pseries and will be used in a subsequent
patch. So, move it to a more appropriate place under
arch/powerpc/platforms/pseries. Also merge vphn.h into lppaca.h
and update vphn selftest to use the new files.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-04 22:23:38 +10:00
Naveen N. Rao
ef34e0efa2 powerpc/pseries: Generalize hcall_vphn()
H_HOME_NODE_ASSOCIATIVITY hcall can take two different flags and return
different associativity information in each case. Generalize the
existing hcall_vphn() function to take flags as an argument and to
return the result. Update the only existing user to pass the proper
arguments.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-04 22:23:38 +10:00
Masahiro Yamada
6d3ca7e736 powerpc/mm: mark more tlb functions as __always_inline
With CONFIG_OPTIMIZE_INLINING enabled, Laura Abbott reported error
with gcc 9.1.1:

  arch/powerpc/mm/book3s64/radix_tlb.c: In function '_tlbiel_pid':
  arch/powerpc/mm/book3s64/radix_tlb.c:104:2: warning: asm operand 3 probably doesn't match constraints
    104 |  asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
        |  ^~~
  arch/powerpc/mm/book3s64/radix_tlb.c:104:2: error: impossible constraint in 'asm'

Fixing _tlbiel_pid() is enough to address the warning above, but I
inlined more functions to fix all potential issues.

To meet the "i" (immediate) constraint for the asm operands, functions
propagating "ric" must be always inlined.

Fixes: 9012d01166 ("compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING")
Reported-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-03 20:49:50 +10:00
Nicholas Piggin
6c46fcce39 powerpc/64s/radix: keep kernel ERAT over local process/guest invalidates
ISA v3.0 radix modes provide SLBIA variants which can invalidate ERAT
for effPID!=0 or for effLPID!=0, which allows user and guest
invalidations to retain kernel/host ERAT entries.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-03 15:19:35 +10:00
Nicholas Piggin
fe7946ce08 powerpc/64s: Rename PPC_INVALIDATE_ERAT to PPC_ISA_3_0_INVALIDATE_ERAT
This makes it clear to the caller that it can only be used on POWER9
and later CPUs.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use "ISA_3_0" rather than "ARCH_300"]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-03 15:19:35 +10:00
Christoph Hellwig
7eb3cf7619 powerpc/powernv: remove unused NPU DMA code
None of these routines were ever used anywhere in the kernel tree
since they were added to the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Michael Ellerman
8b8dc69514 Merge branch 'fixes' into next
Merge our fixes branch into next, this brings in a number of commits
that fix bugs we don't want to hit in next, in particular the fix for
CVE-2019-12817.
2019-07-01 14:04:39 +10:00
Michael Ellerman
b7cbb52401 powerpc fixes for 5.2 #6
One fix for a bug in our context id handling on 64-bit hash CPUs, which can lead
 to unrelated processes being able to read/write to each other's virtual memory.
 See the commit for full details.
 
 That is the fix for CVE-2019-12817.
 
 This also adds a kernel selftest for the bug.
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Merge tag 'powerpc-5.2-6' into fixes

This merges the commits that were the fix for CVE-2019-12817, which was
developed under embargo. They have already been merged by Linus

Merge them into fixes now so that this branch contains all the fixes for
this release.
2019-07-01 13:59:40 +10:00
Christoph Hellwig
9739ab7eda powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac
With the strict dma mask checking introduced with the switch to
the generic DMA direct code common wifi chips on 32-bit powerbooks
stopped working.  Add a 30-bit ZONE_DMA to the 32-bit pmac builds
to allow them to reliably allocate dma coherent memory.

Fixes: 65a21b71f9 ("powerpc/dma: remove dma_nommu_dma_supported")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-19 22:31:20 +10:00
Nicholas Piggin
d909f9109c powerpc/64s/radix: Enable HAVE_ARCH_HUGE_VMAP
This sets the HAVE_ARCH_HUGE_VMAP option, and defines the required
page table functions.

This enables huge (2MB and 1GB) ioremap mappings. I don't have a
benchmark for this change, but huge vmap will be used by a later core
kernel change to enable huge vmalloc memory mappings. This improves
cached `git diff` performance by about 5% on a 2-node POWER9 with 32MB
size dentry cache hash.

  Profiling git diff dTLB misses with a vanilla kernel:

  81.75%  git      [kernel.vmlinux]    [k] __d_lookup_rcu
   7.21%  git      [kernel.vmlinux]    [k] strncpy_from_user
   1.77%  git      [kernel.vmlinux]    [k] find_get_entry
   1.59%  git      [kernel.vmlinux]    [k] kmem_cache_free

            40,168      dTLB-miss
       0.100342754 seconds time elapsed

  With powerpc huge vmalloc:

             2,987      dTLB-miss
       0.095933138 seconds time elapsed

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-19 20:05:09 +10:00
Nicholas Piggin
d38153f9cc powerpc/64s/radix: ioremap use ioremap_page_range
Radix can use ioremap_page_range for ioremap, after slab is available.
This makes it possible to enable huge ioremap mapping support.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-19 20:05:09 +10:00
Nicholas Piggin
a72808a7ec powerpc/64: __ioremap_at clean up in the error case
__ioremap_at error handling is wonky, it requires caller to clean up
after it. Implement a helper that does the map and error cleanup and
remove the requirement from the caller.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-19 20:05:09 +10:00
Andreas Schwab
46c2478af6 powerpc/mm/32s: fix condition that is always true
Move a misplaced paren that makes the condition always true.

Fixes: 63b2bc6195 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-19 20:05:08 +10:00
Michael Ellerman
65565a68c5 Merge branch 'context-id-fix' into fixes
This merges a fix for a bug in our context id handling on 64-bit hash
CPUs.

The fix was written against v5.1 to ease backporting to stable
releases. Here we are merging it up to a v5.2-rc2 base, which involves
a bit of manual resolution.

It also adds a test case for the bug.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-13 15:00:34 +10:00
Michael Ellerman
ca72d88378 powerpc/mm/64s/hash: Reallocate context ids on fork
When using the Hash Page Table (HPT) MMU, userspace memory mappings
are managed at two levels. Firstly in the Linux page tables, much like
other architectures, and secondly in the SLB (Segment Lookaside
Buffer) and HPT. It's the SLB and HPT that are actually used by the
hardware to do translations.

As part of the series adding support for 4PB user virtual address
space using the hash MMU, we added support for allocating multiple
"context ids" per process, one for each 512TB chunk of address space.
These are tracked in an array called extended_id in the mm_context_t
of a process that has done a mapping above 512TB.

If such a process forks (ie. clone(2) without CLONE_VM set) it's mm is
copied, including the mm_context_t, and then init_new_context() is
called to reinitialise parts of the mm_context_t as appropriate to
separate the address spaces of the two processes.

The key step in ensuring the two processes have separate address
spaces is to allocate a new context id for the process, this is done
at the beginning of hash__init_new_context(). If we didn't allocate a
new context id then the two processes would share mappings as far as
the SLB and HPT are concerned, even though their Linux page tables
would be separate.

For mappings above 512TB, which use the extended_id array, we
neglected to allocate new context ids on fork, meaning the parent and
child use the same ids and therefore share those mappings even though
they're supposed to be separate. This can lead to the parent seeing
writes done by the child, which is essentially memory corruption.

There is an additional exposure which is that if the child process
exits, all its context ids are freed, including the context ids that
are still in use by the parent for mappings above 512TB. One or more
of those ids can then be reallocated to a third process, that process
can then read/write to the parent's mappings above 512TB. Additionally
if the freed id is used for the third process's primary context id,
then the parent is able to read/write to the third process's mappings
*below* 512TB.

All of these are fundamental failures to enforce separation between
processes. The only mitigating factor is that the bug only occurs if a
process creates mappings above 512TB, and most applications still do
not create such mappings.

Only machines using the hash page table MMU are affected, eg. PowerPC
970 (G5), PA6T, Power5/6/7/8/9. By default Power9 bare metal machines
(powernv) use the Radix MMU and are not affected, unless the machine
has been explicitly booted in HPT mode (using disable_radix on the
kernel command line). KVM guests on Power9 may be affected if the host
or guest is configured to use the HPT MMU. LPARs under PowerVM on
Power9 are affected as they always use the HPT MMU. Kernels built with
PAGE_SIZE=4K are not affected.

The fix is relatively simple, we need to reallocate context ids for
all extended mappings on fork.

Fixes: f384796c40 ("powerpc/mm: Add support for handling > 512TB address in SLB miss")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-12 23:35:07 +10:00
Nicholas Piggin
a00196a272 powerpc/64s: __find_linux_pte() synchronization vs pmdp_invalidate()
The change to pmdp_invalidate() to mark the pmd with _PAGE_INVALID
broke the synchronisation against lock free lookups,
__find_linux_pte()'s pmd_none() check no longer returns true for such
cases.

Fix this by adding a check for this condition as well.

Fixes: da7ad366b4 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit")
Cc: stable@vger.kernel.org # v4.20+
Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-07 16:28:28 +10:00
Nicholas Piggin
33258a1db1 powerpc/64s: Fix THP PMD collapse serialisation
Commit 1b2443a547 ("powerpc/book3s64: Avoid multiple endian
conversion in pte helpers") changed the actual bitwise tests in
pte_access_permitted by using pte_write() and pte_present() helpers
rather than raw bitwise testing _PAGE_WRITE and _PAGE_PRESENT bits.

The pte_present() change now returns true for PTEs which are
!_PAGE_PRESENT and _PAGE_INVALID, which is the combination used by
pmdp_invalidate() to synchronize access from lock-free lookups.
pte_access_permitted() is used by pmd_access_permitted(), so allowing
GUP lock free access to proceed with such PTEs breaks this
synchronisation.

This bug has been observed on a host using the hash page table MMU,
with random crashes and corruption in guests, usually together with
bad PMD messages in the host.

Fix this by adding an explicit check in pmd_access_permitted(), and
documenting the condition explicitly.

The pte_write() change should be okay, and would prevent GUP from
falling back to the slow path when encountering savedwrite PTEs, which
matches what x86 (that does not implement savedwrite) does.

Fixes: 1b2443a547 ("powerpc/book3s64: Avoid multiple endian conversion in pte helpers")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-07 16:26:44 +10:00
YueHaibing
d667edc01b powerpc/mm: Make some symbols static that can be
Noticed by sparse.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-28 12:08:10 +10:00
Linus Torvalds
86a78a8b8d powerpc fixes for 5.2 #2
One fix going back to stable, for a bug on 32-bit introduced when we added
 support for THREAD_INFO_IN_TASK.
 
 A fix for a typo in a recent rework of our hugetlb code that leads to crashes on
 64-bit when using hugetlbfs with a 4K PAGE_SIZE.
 
 Two fixes for our recent rework of the address layout on 64-bit hash CPUs, both
 only triggered when userspace tries to access addresses outside the user or
 kernel address ranges.
 
 Finally a fix for a recently introduced double free in an error path in our
 cacheinfo code.
 
 Thanks to:
   Aneesh Kumar K.V, Christophe Leroy, Sachin Sant, Tobin C. Harding.
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Merge tag 'powerpc-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "One fix going back to stable, for a bug on 32-bit introduced when we
  added support for THREAD_INFO_IN_TASK.

  A fix for a typo in a recent rework of our hugetlb code that leads to
  crashes on 64-bit when using hugetlbfs with a 4K PAGE_SIZE.

  Two fixes for our recent rework of the address layout on 64-bit hash
  CPUs, both only triggered when userspace tries to access addresses
  outside the user or kernel address ranges.

  Finally a fix for a recently introduced double free in an error path
  in our cacheinfo code.

  Thanks to: Aneesh Kumar K.V, Christophe Leroy, Sachin Sant, Tobin C.
  Harding"

* tag 'powerpc-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/cacheinfo: Remove double free
  powerpc/mm/hash: Fix get_region_id() for invalid addresses
  powerpc/mm: Drop VM_BUG_ON in get_region_id()
  powerpc/mm: Fix crashes with hugepages & 4K pages
  powerpc/32s: fix flush_hash_pages() on SMP
2019-05-19 10:10:15 -07:00
Masahiro Yamada
efc344c57e powerpc/mm/radix: mark as __tlbie_pid() and friends as__always_inline
This prepares to move CONFIG_OPTIMIZE_INLINING from x86 to a common
place.  We need to eliminate potential issues beforehand.

If it is enabled for powerpc, the following errors are reported:

  arch/powerpc/mm/tlb-radix.c: In function '__tlbie_lpid':
  arch/powerpc/mm/tlb-radix.c:148:2: warning: asm operand 3 probably doesn't match constraints
    asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
    ^~~
  arch/powerpc/mm/tlb-radix.c:148:2: error: impossible constraint in 'asm'
  arch/powerpc/mm/tlb-radix.c: In function '__tlbie_pid':
  arch/powerpc/mm/tlb-radix.c:118:2: warning: asm operand 3 probably doesn't match constraints
    asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
    ^~~
  arch/powerpc/mm/tlb-radix.c: In function '__tlbiel_pid':
  arch/powerpc/mm/tlb-radix.c:104:2: warning: asm operand 3 probably doesn't match constraints
    asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
    ^~~

Link: http://lkml.kernel.org/r/20190423034959.13525-11-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 19:52:48 -07:00
Masahiro Yamada
e12d6d7d46 powerpc/mm/radix: mark __radix__flush_tlb_range_psize() as __always_inline
This prepares to move CONFIG_OPTIMIZE_INLINING from x86 to a common
place.  We need to eliminate potential issues beforehand.

If it is enabled for powerpc, the following error is reported:

  arch/powerpc/mm/tlb-radix.c: In function '__radix__flush_tlb_range_psize':
  arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't match constraints [-Werror]
    asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
    ^~~
  arch/powerpc/mm/tlb-radix.c:104:2: error: impossible constraint in 'asm'

Link: http://lkml.kernel.org/r/20190423034959.13525-10-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 19:52:48 -07:00
Michael Ellerman
7338874c33 powerpc/mm: Fix crashes with hugepages & 4K pages
The recent commit to cleanup ifdefs in the hugepage initialisation led
to crashes when using 4K pages as reported by Sachin:

  BUG: Kernel NULL pointer dereference at 0x0000001c
  Faulting instruction address: 0xc000000001d1e58c
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  ...
  CPU: 3 PID: 4635 Comm: futex_wake04 Tainted: G        W  O      5.1.0-next-20190507-autotest #1
  NIP:  c000000001d1e58c LR: c000000001d1e54c CTR: 0000000000000000
  REGS: c000000004937890 TRAP: 0300
  MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 22424822  XER: 00000000
  CFAR: c00000000183e9e0 DAR: 000000000000001c DSISR: 40000000 IRQMASK: 0
  ...
  NIP kmem_cache_alloc+0xbc/0x5a0
  LR  kmem_cache_alloc+0x7c/0x5a0
  Call Trace:
    huge_pte_alloc+0x580/0x950
    hugetlb_fault+0x9a0/0x1250
    handle_mm_fault+0x490/0x4a0
    __do_page_fault+0x77c/0x1f00
    do_page_fault+0x28/0x50
    handle_page_fault+0x18/0x38

This is caused by us trying to allocate from a NULL kmem cache in
__hugepte_alloc(). The kmem cache is NULL because it was never
allocated in hugetlbpage_init(), because add_huge_page_size() returned
an error.

The reason add_huge_page_size() returned an error is a simple typo, we
are calling check_and_get_huge_psize(size) when we should be passing
shift instead.

The fact that we're able to trigger this path when the kmem caches are
NULL is a separate bug, ie. we should not advertise any hugepage sizes
if we haven't setup the required caches for them.

This was only seen with 4K pages, with 64K pages we don't need to
allocate any extra kmem caches because the 16M hugepage just occupies
a single entry at the PMD level.

Fixes: 723f268f19 ("powerpc/mm: cleanup ifdef mess in add_huge_page_size()")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
2019-05-15 11:13:35 +10:00
David Hildenbrand
ac5c942645 mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail
All callers of arch_remove_memory() ignore errors.  And we should really
try to remove any errors from the memory removal path.  No more errors are
reported from __remove_pages().  BUG() in s390x code in case
arch_remove_memory() is triggered.  We may implement that properly later.
WARN in case powerpc code failed to remove the section mapping, which is
better than ignoring the error completely right now.

Link: http://lkml.kernel.org/r/20190409100148.24703-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:50 -07:00
Michal Hocko
940519f0c8 mm, memory_hotplug: provide a more generic restrictions for memory hotplug
arch_add_memory, __add_pages take a want_memblock which controls whether
the newly added memory should get the sysfs memblock user API (e.g.
ZONE_DEVICE users do not want/need this interface).  Some callers even
want to control where do we allocate the memmap from by configuring
altmap.

Add a more generic hotplug context for arch_add_memory and __add_pages.
struct mhp_restrictions contains flags which contains additional features
to be enabled by the memory hotplug (MHP_MEMBLOCK_API currently) and
altmap for alternative memmap allocator.

This patch shouldn't introduce any functional change.

[akpm@linux-foundation.org: build fix]
Link: http://lkml.kernel.org/r/20190408082633.2864-3-osalvador@suse.de
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:49 -07:00
Christoph Hellwig
4afd58e14d initramfs: provide a generic free_initrd_mem implementation
For most architectures free_initrd_mem just expands to the same
free_reserved_area call.  Provide that as a generic implementation marked
__weak.

Link: http://lkml.kernel.org/r/20190213174621.29297-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Steven Price <steven.price@arm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:47 -07:00
Ira Weiny
932f4a630a mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERM
Pach series "Add FOLL_LONGTERM to GUP fast and use it".

HFI1, qib, and mthca, use get_user_pages_fast() due to its performance
advantages.  These pages can be held for a significant time.  But
get_user_pages_fast() does not protect against mapping FS DAX pages.

Introduce FOLL_LONGTERM and use this flag in get_user_pages_fast() which
retains the performance while also adding the FS DAX checks.  XDP has also
shown interest in using this functionality.[1]

In addition we change get_user_pages() to use the new FOLL_LONGTERM flag
and remove the specialized get_user_pages_longterm call.

[1] https://lkml.org/lkml/2019/3/19/939

"longterm" is a relative thing and at this point is probably a misnomer.
This is really flagging a pin which is going to be given to hardware and
can't move.  I've thought of a couple of alternative names but I think we
have to settle on if we are going to use FL_LAYOUT or something else to
solve the "longterm" problem.  Then I think we can change the flag to a
better name.

Secondly, it depends on how often you are registering memory.  I have
spoken with some RDMA users who consider MR in the performance path...
For the overall application performance.  I don't have the numbers as the
tests for HFI1 were done a long time ago.  But there was a significant
advantage.  Some of which is probably due to the fact that you don't have
to hold mmap_sem.

Finally, architecturally I think it would be good for everyone to use
*_fast.  There are patches submitted to the RDMA list which would allow
the use of *_fast (they reworking the use of mmap_sem) and as soon as they
are accepted I'll submit a patch to convert the RDMA core as well.  Also
to this point others are looking to use *_fast.

As an aside, Jasons pointed out in my previous submission that *_fast and
*_unlocked look very much the same.  I agree and I think further cleanup
will be coming.  But I'm focused on getting the final solution for DAX at
the moment.

This patch (of 7):

This patch starts a series which aims to support FOLL_LONGTERM in
get_user_pages_fast().  Some callers who would like to do a longterm (user
controlled pin) of pages with the fast variant of GUP for performance
purposes.

Rather than have a separate get_user_pages_longterm() call, introduce
FOLL_LONGTERM and change the longterm callers to use it.

This patch does not change any functionality.  In the short term
"longterm" or user controlled pins are unsafe for Filesystems and FS DAX
in particular has been blocked.  However, callers of get_user_pages_fast()
were not "protected".

FOLL_LONGTERM can _only_ be supported with get_user_pages[_fast]() as it
requires vmas to determine if DAX is in use.

NOTE: In merging with the CMA changes we opt to change the
get_user_pages() call in check_and_migrate_cma_pages() to a call of
__get_user_pages_locked() on the newly migrated pages.  This makes the
code read better in that we are calling __get_user_pages_locked() on the
pages before and after a potential migration.

As a side affect some of the interfaces are cleaned up but this is not the
primary purpose of the series.

In review[1] it was asked:

<quote>
> This I don't get - if you do lock down long term mappings performance
> of the actual get_user_pages call shouldn't matter to start with.
>
> What do I miss?

A couple of points.

First "longterm" is a relative thing and at this point is probably a
misnomer.  This is really flagging a pin which is going to be given to
hardware and can't move.  I've thought of a couple of alternative names
but I think we have to settle on if we are going to use FL_LAYOUT or
something else to solve the "longterm" problem.  Then I think we can
change the flag to a better name.

Second, It depends on how often you are registering memory.  I have spoken
with some RDMA users who consider MR in the performance path...  For the
overall application performance.  I don't have the numbers as the tests
for HFI1 were done a long time ago.  But there was a significant
advantage.  Some of which is probably due to the fact that you don't have
to hold mmap_sem.

Finally, architecturally I think it would be good for everyone to use
*_fast.  There are patches submitted to the RDMA list which would allow
the use of *_fast (they reworking the use of mmap_sem) and as soon as they
are accepted I'll submit a patch to convert the RDMA core as well.  Also
to this point others are looking to use *_fast.

As an asside, Jasons pointed out in my previous submission that *_fast and
*_unlocked look very much the same.  I agree and I think further cleanup
will be coming.  But I'm focused on getting the final solution for DAX at
the moment.

</quote>

[1] https://lore.kernel.org/lkml/20190220180255.GA12020@iweiny-DESK2.sc.intel.com/T/#md6abad2569f3bf6c1f03686c8097ab6563e94965

[ira.weiny@intel.com: v3]
  Link: http://lkml.kernel.org/r/20190328084422.29911-2-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190328084422.29911-2-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-2-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:45 -07:00
Christophe Leroy
397d2300b0 powerpc/32s: fix flush_hash_pages() on SMP
flush_hash_pages() runs with data translation off, so current
task_struct has to be accesssed using physical address.

Fixes: f7354ccac8 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU")
Cc: stable@vger.kernel.org # v5.1+
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-14 22:58:52 +10:00
Linus Torvalds
b970afcfca powerpc updates for 5.2
Highlights:
 
  - Support for Kernel Userspace Access/Execution Prevention (like
    SMAP/SMEP/PAN/PXN) on some 64-bit and 32-bit CPUs. This prevents the kernel
    from accidentally accessing userspace outside copy_to/from_user(), or
    ever executing userspace.
 
  - KASAN support on 32-bit.
 
  - Rework of where we map the kernel, vmalloc, etc. on 64-bit hash to use the
    same address ranges we use with the Radix MMU.
 
  - A rewrite into C of large parts of our idle handling code for 64-bit Book3S
    (ie. power8 & power9).
 
  - A fast path entry for syscalls on 32-bit CPUs, for a 12-17% speedup in the
    null_syscall benchmark.
 
  - On 64-bit bare metal we have support for recovering from errors with the time
    base (our clocksource), however if that fails currently we hang in __delay()
    and never crash. We now have support for detecting that case and short
    circuiting __delay() so we at least panic() and reboot.
 
  - Add support for optionally enabling the DAWR on Power9, which had to be
    disabled by default due to a hardware erratum. This has the effect of
    enabling hardware breakpoints for GDB, the downside is a badly behaved
    program could crash the machine by pointing the DAWR at cache inhibited
    memory. This is opt-in obviously.
 
  - xmon, our crash handler, gets support for a read only mode where operations
    that could change memory or otherwise disturb the system are disabled.
 
 Plus many clean-ups, reworks and minor fixes etc.
 
 Thanks to:
   Christophe Leroy, Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Andrew
   Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Ben Hutchings,
   Bo YU, Breno Leitao, Cédric Le Goater, Christopher M. Riedl, Christoph
   Hellwig, Colin Ian King, David Gibson, Ganesh Goudar, Gautham R. Shenoy,
   George Spelvin, Greg Kroah-Hartman, Greg Kurz, Horia Geantă, Jagadeesh
   Pagadala, Joel Stanley, Joe Perches, Julia Lawall, Laurentiu Tudor, Laurent
   Vivier, Lukas Bulwahn, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu
   Malaterre, Michael Neuling, Mukesh Ojha, Nathan Fontenot, Nathan Lynch,
   Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Peng Hao, Qian Cai, Ravi
   Bangoria, Rick Lindsley, Russell Currey, Sachin Sant, Stewart Smith, Sukadev
   Bhattiprolu, Thomas Huth, Tobin C. Harding, Tyrel Datwyler, Valentin
   Schneider, Wei Yongjun, Wen Yang, YueHaibing.
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Merge tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Slightly delayed due to the issue with printk() calling
  probe_kernel_read() interacting with our new user access prevention
  stuff, but all fixed now.

  The only out-of-area changes are the addition of a cpuhp_state, small
  additions to Documentation and MAINTAINERS updates.

  Highlights:

   - Support for Kernel Userspace Access/Execution Prevention (like
     SMAP/SMEP/PAN/PXN) on some 64-bit and 32-bit CPUs. This prevents
     the kernel from accidentally accessing userspace outside
     copy_to/from_user(), or ever executing userspace.

   - KASAN support on 32-bit.

   - Rework of where we map the kernel, vmalloc, etc. on 64-bit hash to
     use the same address ranges we use with the Radix MMU.

   - A rewrite into C of large parts of our idle handling code for
     64-bit Book3S (ie. power8 & power9).

   - A fast path entry for syscalls on 32-bit CPUs, for a 12-17% speedup
     in the null_syscall benchmark.

   - On 64-bit bare metal we have support for recovering from errors
     with the time base (our clocksource), however if that fails
     currently we hang in __delay() and never crash. We now have support
     for detecting that case and short circuiting __delay() so we at
     least panic() and reboot.

   - Add support for optionally enabling the DAWR on Power9, which had
     to be disabled by default due to a hardware erratum. This has the
     effect of enabling hardware breakpoints for GDB, the downside is a
     badly behaved program could crash the machine by pointing the DAWR
     at cache inhibited memory. This is opt-in obviously.

   - xmon, our crash handler, gets support for a read only mode where
     operations that could change memory or otherwise disturb the system
     are disabled.

  Plus many clean-ups, reworks and minor fixes etc.

  Thanks to: Christophe Leroy, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar,
  Anton Blanchard, Ben Hutchings, Bo YU, Breno Leitao, Cédric Le Goater,
  Christopher M. Riedl, Christoph Hellwig, Colin Ian King, David Gibson,
  Ganesh Goudar, Gautham R. Shenoy, George Spelvin, Greg Kroah-Hartman,
  Greg Kurz, Horia Geantă, Jagadeesh Pagadala, Joel Stanley, Joe
  Perches, Julia Lawall, Laurentiu Tudor, Laurent Vivier, Lukas Bulwahn,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
  Neuling, Mukesh Ojha, Nathan Fontenot, Nathan Lynch, Nicholas Piggin,
  Nick Desaulniers, Oliver O'Halloran, Peng Hao, Qian Cai, Ravi
  Bangoria, Rick Lindsley, Russell Currey, Sachin Sant, Stewart Smith,
  Sukadev Bhattiprolu, Thomas Huth, Tobin C. Harding, Tyrel Datwyler,
  Valentin Schneider, Wei Yongjun, Wen Yang, YueHaibing"

* tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (205 commits)
  powerpc/64s: Use early_mmu_has_feature() in set_kuap()
  powerpc/book3s/64: check for NULL pointer in pgd_alloc()
  powerpc/mm: Fix hugetlb page initialization
  ocxl: Fix return value check in afu_ioctl()
  powerpc/mm: fix section mismatch for setup_kup()
  powerpc/mm: fix redundant inclusion of pgtable-frag.o in Makefile
  powerpc/mm: Fix makefile for KASAN
  powerpc/kasan: add missing/lost Makefile
  selftests/powerpc: Add a signal fuzzer selftest
  powerpc/booke64: set RI in default MSR
  ocxl: Provide global MMIO accessors for external drivers
  ocxl: move event_fd handling to frontend
  ocxl: afu_irq only deals with IRQ IDs, not offsets
  ocxl: Allow external drivers to use OpenCAPI contexts
  ocxl: Create a clear delineation between ocxl backend & frontend
  ocxl: Don't pass pci_dev around
  ocxl: Split pci.c
  ocxl: Remove some unused exported symbols
  ocxl: Remove superfluous 'extern' from headers
  ocxl: read_pasid never returns an error, so make it void
  ...
2019-05-10 05:29:27 -07:00
Sachin Sant
04a1942933 powerpc/mm: Fix hugetlb page initialization
This patch fixes a regression by using correct kernel config variable
for HUGETLB_PAGE_SIZE_VARIABLE.

Without this huge pages are disabled during kernel boot.
[0.309496] hugetlbfs: disabling because there are no supported hugepage sizes

Fixes: c5710cd207 ("powerpc/mm: cleanup HPAGE_SHIFT setup")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-06 22:37:39 +10:00
Christophe Leroy
67d53f30e2 powerpc/mm: fix section mismatch for setup_kup()
commit b28c97505e ("powerpc/64: Setup KUP on secondary CPUs")
moved setup_kup() out of the __init section. As stated in that commit,
"this is only for 64-bit". But this function is also used on PPC32,
where the two functions called by setup_kup() are in the __init
section, so setup_kup() has to either be kept in the __init
section on PPC32 or marked __ref.

This patch marks it __ref, it fixes the below build warnings.

  MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x169ec): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuep()
The function setup_kup() references
the function __init setup_kuep().
This is often because setup_kup lacks a __init
annotation or the annotation of setup_kuep is wrong.

WARNING: vmlinux.o(.text+0x16a04): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuap()
The function setup_kup() references
the function __init setup_kuap().
This is often because setup_kup lacks a __init
annotation or the annotation of setup_kuap is wrong.

Fixes: b28c97505e ("powerpc/64: Setup KUP on secondary CPUs")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-06 20:21:56 +10:00
Christophe Leroy
c4e31847a5 powerpc/mm: fix redundant inclusion of pgtable-frag.o in Makefile
The patch identified below added pgtable-frag.o to obj-y
but some merge witchery kept it also for obj-CONFIG_PPC_BOOK3S_64

This patch clears the duplication.

Fixes: 737b434d3d ("powerpc/mm: convert Book3E 64 to pte_fragment")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-06 20:21:56 +10:00
Christophe Leroy
471e475c69 powerpc/mm: Fix makefile for KASAN
In commit 17312f258c ("powerpc/mm: Move book3s32 specifics in
subdirectory mm/book3s64"), ppc_mmu_32.c was moved and renamed.

This patch fixes Makefiles to disable KASAN instrumentation on
the new name and location.

Fixes: f072015c7b ("powerpc: disable KASAN instrumentation on early/critical files.")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-06 20:21:56 +10:00
Christophe Leroy
305d600123 powerpc/kasan: add missing/lost Makefile
For unknown reason (aka. mpe is a doofus), the new Makefile added via
the KASAN support patch didn't land into arch/powerpc/mm/kasan/

This patch restores it.

Fixes: 2edb16efc8 ("powerpc/32: Add KASAN support")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-06 20:21:34 +10:00
Russell Currey
453d87f6a8 powerpc/mm: Warn if W+X pages found on boot
Implement code to walk all pages and warn if any are found to be both
writable and executable.  Depends on STRICT_KERNEL_RWX enabled, and is
behind the DEBUG_WX config option.

This only runs on boot and has no runtime performance implications.

Very heavily influenced (and in some cases copied verbatim) from the
ARM64 code written by Laura Abbott (thanks!), since our ptdump
infrastructure is similar.

Signed-off-by: Russell Currey <ruscur@russell.cc>
[mpe: Fixup build error when disabled]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:54:45 +10:00
Russell Currey
5f18cbdbdd powerpc/mm/ptdump: Wrap seq_printf() to handle NULL pointers
Lovingly borrowed from the arch/arm64 ptdump code.

This doesn't seem to be an issue in practice, but is necessary for my
upcoming commit.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:58:11 +10:00
Christoph Hellwig
c9e0fc33b8 powerpc: remove the __kernel_io_end export
This export was added in this merge window, but without any actual
user, or justification for a modular user.

Fixes: a35a3c6f60 ("powerpc/mm/hash64: Add a variable to track the end of IO mapping")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:58:11 +10:00
Christophe Leroy
e4dccf9092 powerpc/mm: print hash info in a helper
Reduce #ifdef mess by defining a helper to print
hash info at startup.

In the meantime, remove the display of hash table address
to reduce leak of non necessary information.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:26 +10:00
Christophe Leroy
8f156c23f4 powerpc/32s: don't try to print hash table address.
Due to %p, (ptrval) is printed in lieu of the hash table address.

showing the hash table address isn't an operationnal need so just
don't print it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:26 +10:00
Christophe Leroy
57e0491b58 powerpc/32s: drop Hash_end
Hash_end has never been used, drop it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:26 +10:00
Christophe Leroy
da3a3b0a0e powerpc/32s: map kasan zero shadow with PAGE_READONLY instead of PAGE_KERNEL_RO
For hash32, the zero shadow page gets mapped with PAGE_READONLY instead
of PAGE_KERNEL_RO, because the PP bits don't provide a RO kernel, so
PAGE_KERNEL_RO is equivalent to PAGE_KERNEL. By using PAGE_READONLY,
the page is RO for both kernel and user, but this is not a security issue
as it contains only zeroes.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 01:20:26 +10:00