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  1. Dec 20, 2018
    • Madhavan Srinivasan's avatar
      powerpc/perf: Fix thresholding counter data for unknown type · 17cfccc9
      Madhavan Srinivasan authored 
      MMCRA[34:36] and MMCRA[38:44] expose the thresholding counter value.
Thresholding counter can be used to count latency cycles such as
load miss to reload. But threshold counter value is not relevant
when the sampled instruction type is unknown or reserved. Patch to
fix the thresholding counter value to zero when sampled instruction
type is unknown or reserved.

Fixes: 170a315f

('powerpc/perf: Support to export MMCRA[TEC*] field to userspace')
Signed-off-by: default avatarMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      17cfccc9
    • Aneesh Kumar K.V's avatar
      powerpc/mm/hash: Handle user access of kernel address gracefully · 374f3f59
      Aneesh Kumar K.V authored 
      In commit 2865d08d ("powerpc/mm: Move the DSISR_PROTFAULT sanity
check") we moved the protection fault access check before the vma
lookup. That means we hit that WARN_ON when user space accesses a
kernel address. Before that commit this was handled by find_vma() not
finding vma for the kernel address and considering that access as bad
area access.

Avoid the confusing WARN_ON and convert that to a ratelimited printk.

With the patch we now get:

for load:
  a.out[5997]: User access of kernel address (c00000000000dea0) - exploit attempt? (uid: 1000)
  a.out[5997]: segfault (11) at c00000000000dea0 nip 1317c0798 lr 7fff80d6441c code 1 in a.out[1317c0000+10000]
  a.out[5997]: code: 60000000 60420000 3c4c0002 38427790 4bffff20 3c4c0002 38427784 fbe1fff8
  a.out[5997]: code: f821ffc1 7c3f0b78 60000000 e9228030 <89290000> 993f002f 60000000 383f0040

for exec:
  a.out[6067]: User access of kernel address (c00000000000dea0) - exploit attempt? (uid: 1000)
  a.out[6067]: segfault (11) at c00000000000dea0 nip c00000000000dea0 lr 129d507b0 code 1
  a.out[6067]: Bad NIP, not dumping instructions.

Fixes: 2865d08d

 ("powerpc/mm: Move the DSISR_PROTFAULT sanity check")
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Tested-by: default avatarBreno Leitao <leitao@debian.org>
[mpe: Don't split printk() string across lines]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      374f3f59
  3. Dec 19, 2018
  5. Dec 17, 2018
  7. Dec 10, 2018
  9. Dec 09, 2018
    • Oliver O'Halloran's avatar
      powerpc/mm: Fallback to RAM if the altmap is unusable · 9ef34630
      Oliver O'Halloran authored 
      The "altmap" is used to provide a pool of memory that is reserved for
the vmemmap backing of hot-plugged memory. This is useful when adding
large amount of ZONE_DEVICE memory to a system with a limited amount of
normal memory.

On ppc64 we use huge pages to map the vmemmap which requires the backing
storage to be contigious and aligned to the hugepage size. The altmap
implementation allows for the altmap provider to reserve a few PFNs at
the start of the range for it's own uses and when this occurs the
first chunk of the altmap is not usable for hugepage mappings. On hash
there is no sane way to fall back to a normal sized page mapping so we
fail the allocation. This results in memory hotplug failing with
ENOMEM when the new range doesn't fall into an existing vmemmap block.

This patch handles this case by falling back to using system memory
rather than failing if we cannot allocate from the altmap. This
fallback should only ever be used for the first vmemmap block so it
should not cause excess memory consumption.

Fixes: 7b73d978

 ("mm: pass the vmem_altmap to vmemmap_populate")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      9ef34630
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Use ibm,unit-guid as the iset cookie · 43001c52
      Oliver O'Halloran authored 
      The interleave set cookie is used to determine if a label stored in the
metadata space should be applied to the current region. This is
important in the case of NVDIMMs since the firmware may change the
interleaving configuration of a DIMM which would invalidate the existing
labels. In our case the hypervisor hides those details from us so we
don't really care, but libnvdimm still requires the interleave set
cookie to be non-zero.

For our purposes we just need the set cookie to be unique and fixed for
a given PAPR SCM region and using the unit-guid (really a UUID) is fine
for this purpose.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
[mpe: Use kernel types (u64)]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      43001c52
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Fix DIMM device registration race · b0d65a8c
      Oliver O'Halloran authored 
      When a new nvdimm device is registered with libnvdimm via
nvdimm_create() it is added as a device on the nvdimm bus. The probe
function for the DIMM driver is potentially quite slow so actually
registering and probing the device is done in an async domain rather
than immediately after device creation. This can result in a race where
the region device (created 2nd) is probed first and fails to activate at
boot.

To fix this we use the same approach as the ACPI/NFIT driver which is to
check that all the DIMM devices registered successfully. LibNVDIMM
provides the nvdimm_bus_count_dimms() function which synchronises with
the async domain and verifies that the dimm was successfully registered
with the bus.

If either of these does not occur then we bail.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      b0d65a8c
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Remove endian conversions · 409dd7dc
      Oliver O'Halloran authored 
      The return values of a h-call are returned in the CPU registers and
written to the provided buffer by the plpar_hcall() wrapper. As a result
the values written to memory are always in the native endian and should
not be byte swapped.

The inital implementation of the H-Call interface was done in qemu and
the returned values were byte swapped unnecessarily in both the
hypervisor and in the driver so this was only noticed when bringing up
the PowerVM implementation.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      409dd7dc
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Update DT properties · 683ec0e0
      Oliver O'Halloran authored 
      The ibm,unit-sizes property was originally specified as an array of two
u32s corresponding to the memory block size, and the number of blocks
available in that region. A fairly last-minute change to the SCM DT
specification was splitting that into two seperate u64 properties:
ibm,block-sizes and ibm,number-of-blocks that convey the same
information. No firmware / hypervisor that emitted the ibm,unit-size
property ever appeared in the wild.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
[mpe: Use kernel types (u32/u64)]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      683ec0e0
  11. Dec 07, 2018
  13. Dec 06, 2018
    • Michael Ellerman's avatar
      powerpc/boot: Fix build failures with -j 1 · e41b93a6
      Michael Ellerman authored 
      In commit 5e9dcb61 ("powerpc/boot: Expose Kconfig symbols to
wrapper") we added a dependency to serial.c on autoconf.h:

  $(obj)/serial.c: $(obj)/autoconf.h

This works when building in-tree (ie. with KBUILD_OUTPUT unset)
because the obj tree is the src tree.

But when building with eg. O=build and -j 1 the build fails:

  gcc ... -I../arch/powerpc/boot -c -o arch/powerpc/boot/serial.o arch/powerpc/boot/serial.c
  gcc: error: arch/powerpc/boot/serial.c: No such file or directory

Why this is only happening with -j 1 is not clear, when building with
-j greater than 1 somehow we decide to look for serial.c in the src
tree (../), eg:

  gcc -I../arch/powerpc/boot -c -o arch/powerpc/boot/serial.o ../arch/powerpc/boot/serial.c

Regardless we shouldn't be specifying a dependency on serial.c in the
build tree, we want to add a dependency to the version in $(srctree)
so fix the rule to say that.

Fixes: 5e9dcb61

 ("powerpc/boot: Expose Kconfig symbols to wrapper")
Tested-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      e41b93a6
  15. Dec 04, 2018