<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/arch/powerpc/include, branch linux-4.18.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.18.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.18.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2018-11-21T08:22:04Z</updated>
<entry>
<title>Revert "powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP"</title>
<updated>2018-11-21T08:22:04Z</updated>
<author>
<name>Christophe Leroy</name>
</author>
<published>2018-10-19T06:54:54Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=dd4f21dfb81db8fa82607db8fda76d597b191f36'/>
<id>urn:sha1:dd4f21dfb81db8fa82607db8fda76d597b191f36</id>
<content type='text'>
commit cc4ebf5c0a3440ed0a32d25c55ebdb6ce5f3c0bc upstream.

This reverts commit 4f94b2c7462d9720b2afa7e8e8d4c19446bb31ce.

That commit was buggy, as it used rlwinm instead of rlwimi.
Instead of fixing that bug, we revert the previous commit in order to
reduce the dependency between L1 entries and L2 entries

Fixes: 4f94b2c7462d9 ("powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>powerpc/msi: Fix compile error on mpc83xx</title>
<updated>2018-11-13T19:12:47Z</updated>
<author>
<name>Christophe Leroy</name>
</author>
<published>2018-10-19T06:12:50Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=c0668860758ead905b998dc78e9e61a814ff43fa'/>
<id>urn:sha1:c0668860758ead905b998dc78e9e61a814ff43fa</id>
<content type='text'>
commit 0f99153def98134403c9149128e59d3e1786cf04 upstream.

mpic_get_primary_version() is not defined when not using MPIC.
The compile error log like:

arch/powerpc/sysdev/built-in.o: In function `fsl_of_msi_probe':
fsl_msi.c:(.text+0x150c): undefined reference to `fsl_mpic_primary_get_version'

Signed-off-by: Jia Hongtao &lt;hongtao.jia@freescale.com&gt;
Signed-off-by: Scott Wood &lt;scottwood@freescale.com&gt;
Reported-by: Radu Rendec &lt;radu.rendec@gmail.com&gt;
Fixes: 807d38b73b6 ("powerpc/mpic: Add get_version API both for internal and external use")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm: Preserve _PAGE_DEVMAP across mprotect() calls</title>
<updated>2018-10-18T07:18:20Z</updated>
<author>
<name>Jan Kara</name>
</author>
<published>2018-10-09T10:19:17Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=a249cdf8fc74b464fdbdbabd4d06e15a22ae22a2'/>
<id>urn:sha1:a249cdf8fc74b464fdbdbabd4d06e15a22ae22a2</id>
<content type='text'>
commit 4628a64591e6cee181237060961e98c615c33966 upstream.

Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a
result we will see warnings such as:

BUG: Bad page map in process JobWrk0013  pte:800001803875ea25 pmd:7624381067
addr:00007f0930720000 vm_flags:280000f9 anon_vma:          (null) mapping:ffff97f2384056f0 index:0
file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage:          (null)
CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G        W          4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased)
Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
Call Trace:
 dump_stack+0x5a/0x75
 print_bad_pte+0x217/0x2c0
 ? enqueue_task_fair+0x76/0x9f0
 _vm_normal_page+0xe5/0x100
 zap_pte_range+0x148/0x740
 unmap_page_range+0x39a/0x4b0
 unmap_vmas+0x42/0x90
 unmap_region+0x99/0xf0
 ? vma_gap_callbacks_rotate+0x1a/0x20
 do_munmap+0x255/0x3a0
 vm_munmap+0x54/0x80
 SyS_munmap+0x1d/0x30
 do_syscall_64+0x74/0x150
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
...

when mprotect(2) gets used on DAX mappings. Also there is a wide variety
of other failures that can result from the missing _PAGE_DEVMAP flag
when the area gets used by get_user_pages() later.

Fix the problem by including _PAGE_DEVMAP in a set of flags that get
preserved by mprotect(2).

Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP")
Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reviewed-by: Johannes Thumshirn &lt;jthumshirn@suse.de&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>powerpc: Avoid code patching freed init sections</title>
<updated>2018-10-13T07:33:16Z</updated>
<author>
<name>Michael Neuling</name>
</author>
<published>2018-09-14T01:14:11Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=2025ef74e8c4268569775adb54a6d1f49156af14'/>
<id>urn:sha1:2025ef74e8c4268569775adb54a6d1f49156af14</id>
<content type='text'>
commit 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 upstream.

This stops us from doing code patching in init sections after they've
been freed.

In this chain:
  kvm_guest_init() -&gt;
    kvm_use_magic_page() -&gt;
      fault_in_pages_readable() -&gt;
	 __get_user() -&gt;
	   __get_user_nocheck() -&gt;
	     barrier_nospec();

We have a code patching location at barrier_nospec() and
kvm_guest_init() is an init function. This whole chain gets inlined,
so when we free the init section (hence kvm_guest_init()), this code
goes away and hence should no longer be patched.

We seen this as userspace memory corruption when using a memory
checker while doing partition migration testing on powervm (this
starts the code patching post migration via
/sys/kernel/mobility/migration). In theory, it could also happen when
using /sys/kernel/debug/powerpc/barrier_nospec.

Cc: stable@vger.kernel.org # 4.13+
Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>powerpc/mm: Don't report PUDs as memory leaks when using kmemleak</title>
<updated>2018-09-19T20:41:33Z</updated>
<author>
<name>Michael Ellerman</name>
</author>
<published>2018-07-19T14:33:16Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=dc00dc4ccf8bf18ed839db6925893b8d8f67c93e'/>
<id>urn:sha1:dc00dc4ccf8bf18ed839db6925893b8d8f67c93e</id>
<content type='text'>
[ Upstream commit a984506c542e26b31cbb446438f8439fa2253b2e ]

Paul Menzel reported that kmemleak was producing reports such as:

  unreferenced object 0xc0000000f8b80000 (size 16384):
    comm "init", pid 1, jiffies 4294937416 (age 312.240s)
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [&lt;00000000d997deb7&gt;] __pud_alloc+0x80/0x190
      [&lt;0000000087f2e8a3&gt;] move_page_tables+0xbac/0xdc0
      [&lt;00000000091e51c2&gt;] shift_arg_pages+0xc0/0x210
      [&lt;00000000ab88670c&gt;] setup_arg_pages+0x22c/0x2a0
      [&lt;0000000060871529&gt;] load_elf_binary+0x41c/0x1648
      [&lt;00000000ecd9d2d4&gt;] search_binary_handler.part.11+0xbc/0x280
      [&lt;0000000034e0cdd7&gt;] __do_execve_file.isra.13+0x73c/0x940
      [&lt;000000005f953a6e&gt;] sys_execve+0x58/0x70
      [&lt;000000009700a858&gt;] system_call+0x5c/0x70

Indicating that a PUD was being leaked.

However what's really happening is that kmemleak is not able to
recognise the references from the PGD to the PUD, because they are not
fully qualified pointers.

We can confirm that in xmon, eg:

Find the task struct for pid 1 "init":
  0:mon&gt; P
       task_struct     -&gt;thread.ksp    PID   PPID S  P CMD
  c0000001fe7c0000 c0000001fe803960      1      0 S 13 systemd

Dump virtual address 0 to find the PGD:
  0:mon&gt; dv 0 c0000001fe7c0000
  pgd  @ 0xc0000000f8b01000

Dump the memory of the PGD:
  0:mon&gt; d c0000000f8b01000
  c0000000f8b01000 00000000f8b90000 0000000000000000  |................|
  c0000000f8b01010 0000000000000000 0000000000000000  |................|
  c0000000f8b01020 0000000000000000 0000000000000000  |................|
  c0000000f8b01030 0000000000000000 00000000f8b80000  |................|
                                    ^^^^^^^^^^^^^^^^

There we can see the reference to our supposedly leaked PUD. But
because it's missing the leading 0xc, kmemleak won't recognise it.

We can confirm it's still in use by translating an address that is
mapped via it:
  0:mon&gt; dv 7fff94000000 c0000001fe7c0000
  pgd  @ 0xc0000000f8b01000
  pgdp @ 0xc0000000f8b01038 = 0x00000000f8b80000 &lt;--
  pudp @ 0xc0000000f8b81ff8 = 0x00000000037c4000
  pmdp @ 0xc0000000037c5ca0 = 0x00000000fbd89000
  ptep @ 0xc0000000fbd89000 = 0xc0800001d5ce0386
  Maps physical address = 0x00000001d5ce0000
  Flags = Accessed Dirty Read Write

The fix is fairly simple. We need to tell kmemleak to ignore PUD
allocations and never report them as leaks. We can also tell it not to
scan the PGD, because it will never find pointers in there. However it
will still notice if we allocate a PGD and then leak it.

Reported-by: Paul Menzel &lt;pmenzel@molgen.mpg.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Tested-by: Paul Menzel &lt;pmenzel@molgen.mpg.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc/uaccess: Enable get_user(u64, *p) on 32-bit</title>
<updated>2018-09-15T07:46:51Z</updated>
<author>
<name>Michael Ellerman</name>
</author>
<published>2018-07-10T06:20:56Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=118522ed5fa7f8eac79bbc75e94f7f87efa6c004'/>
<id>urn:sha1:118522ed5fa7f8eac79bbc75e94f7f87efa6c004</id>
<content type='text'>
[ Upstream commit f7a6947cd49b7ff4e03f1b4f7e7b223003d752ca ]

Currently if you build a 32-bit powerpc kernel and use get_user() to
load a u64 value it will fail to build with eg:

  kernel/rseq.o: In function `rseq_get_rseq_cs':
  kernel/rseq.c:123: undefined reference to `__get_user_bad'

This is hitting the check in __get_user_size() that makes sure the
size we're copying doesn't exceed the size of the destination:

  #define __get_user_size(x, ptr, size, retval)
  do {
  	retval = 0;
  	__chk_user_ptr(ptr);
  	if (size &gt; sizeof(x))
  		(x) = __get_user_bad();

Which doesn't immediately make sense because the size of the
destination is u64, but it's not really, because __get_user_check()
etc. internally create an unsigned long and copy into that:

  #define __get_user_check(x, ptr, size)
  ({
  	long __gu_err = -EFAULT;
  	unsigned long  __gu_val = 0;

The problem being that on 32-bit unsigned long is not big enough to
hold a u64. We can fix this with a trick from hpa in the x86 code, we
statically check the type of x and set the type of __gu_val to either
unsigned long or unsigned long long.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc/topology: Get topology for shared processors at boot</title>
<updated>2018-09-15T07:46:47Z</updated>
<author>
<name>Srikar Dronamraju</name>
</author>
<published>2018-08-17T14:54:39Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=dfb5ad65ca177bf030f4523b76849e42684bfe2a'/>
<id>urn:sha1:dfb5ad65ca177bf030f4523b76849e42684bfe2a</id>
<content type='text'>
[ Upstream commit 2ea62630681027c455117aa471ea3ab8bb099ead ]

On a shared LPAR, Phyp will not update the CPU associativity at boot
time. Just after the boot system does recognize itself as a shared
LPAR and trigger a request for correct CPU associativity. But by then
the scheduler would have already created/destroyed its sched domains.

This causes
  - Broken load balance across Nodes causing islands of cores.
  - Performance degradation esp if the system is lightly loaded
  - dmesg to wrongly report all CPUs to be in Node 0.
  - Messages in dmesg saying borken topology.
  - With commit 051f3ca02e46 ("sched/topology: Introduce NUMA identity
    node sched domain"), can cause rcu stalls at boot up.

The sched_domains_numa_masks table which is used to generate cpumasks
is only created at boot time just before creating sched domains and
never updated. Hence, its better to get the topology correct before
the sched domains are created.

For example on 64 core Power 8 shared LPAR, dmesg reports

  Brought up 512 CPUs
  Node 0 CPUs: 0-511
  Node 1 CPUs:
  Node 2 CPUs:
  Node 3 CPUs:
  Node 4 CPUs:
  Node 5 CPUs:
  Node 6 CPUs:
  Node 7 CPUs:
  Node 8 CPUs:
  Node 9 CPUs:
  Node 10 CPUs:
  Node 11 CPUs:
  ...
  BUG: arch topology borken
       the DIE domain not a subset of the NUMA domain
  BUG: arch topology borken
       the DIE domain not a subset of the NUMA domain

numactl/lscpu output will still be correct with cores spreading across
all nodes:

  Socket(s):             64
  NUMA node(s):          12
  Model:                 2.0 (pvr 004d 0200)
  Model name:            POWER8 (architected), altivec supported
  Hypervisor vendor:     pHyp
  Virtualization type:   para
  L1d cache:             64K
  L1i cache:             32K
  NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471
  NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479
  NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487
  NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495
  NUMA node4 CPU(s):     208-215,304-311,400-407,496-503
  NUMA node5 CPU(s):     168-175,264-271,360-367,456-463
  NUMA node6 CPU(s):     128-135,224-231,320-327,416-423
  NUMA node7 CPU(s):     136-143,232-239,328-335,424-431
  NUMA node8 CPU(s):     216-223,312-319,408-415,504-511
  NUMA node9 CPU(s):     144-151,240-247,336-343,432-439
  NUMA node10 CPU(s):    152-159,248-255,344-351,440-447
  NUMA node11 CPU(s):    160-167,256-263,352-359,448-455

Currently on this LPAR, the scheduler detects 2 levels of Numa and
created numa sched domains for all CPUs, but it finds a single DIE
domain consisting of all CPUs. Hence it deletes all numa sched
domains.

To address this, detect the shared processor and update topology soon
after CPUs are setup so that correct topology is updated just before
scheduler creates sched domain.

With the fix, dmesg reports:

  numa: Node 0 CPUs: 0-7 32-39 64-71 96-103 176-183 272-279 368-375 464-471
  numa: Node 1 CPUs: 8-15 40-47 72-79 104-111 184-191 280-287 376-383 472-479
  numa: Node 2 CPUs: 16-23 48-55 80-87 112-119 192-199 288-295 384-391 480-487
  numa: Node 3 CPUs: 24-31 56-63 88-95 120-127 200-207 296-303 392-399 488-495
  numa: Node 4 CPUs: 208-215 304-311 400-407 496-503
  numa: Node 5 CPUs: 168-175 264-271 360-367 456-463
  numa: Node 6 CPUs: 128-135 224-231 320-327 416-423
  numa: Node 7 CPUs: 136-143 232-239 328-335 424-431
  numa: Node 8 CPUs: 216-223 312-319 408-415 504-511
  numa: Node 9 CPUs: 144-151 240-247 336-343 432-439
  numa: Node 10 CPUs: 152-159 248-255 344-351 440-447
  numa: Node 11 CPUs: 160-167 256-263 352-359 448-455

and lscpu also reports:

  Socket(s):             64
  NUMA node(s):          12
  Model:                 2.0 (pvr 004d 0200)
  Model name:            POWER8 (architected), altivec supported
  Hypervisor vendor:     pHyp
  Virtualization type:   para
  L1d cache:             64K
  L1i cache:             32K
  NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471
  NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479
  NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487
  NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495
  NUMA node4 CPU(s):     208-215,304-311,400-407,496-503
  NUMA node5 CPU(s):     168-175,264-271,360-367,456-463
  NUMA node6 CPU(s):     128-135,224-231,320-327,416-423
  NUMA node7 CPU(s):     136-143,232-239,328-335,424-431
  NUMA node8 CPU(s):     216-223,312-319,408-415,504-511
  NUMA node9 CPU(s):     144-151,240-247,336-343,432-439
  NUMA node10 CPU(s):    152-159,248-255,344-351,440-447
  NUMA node11 CPU(s):    160-167,256-263,352-359,448-455

Reported-by: Manjunatha H R &lt;manjuhr1@in.ibm.com&gt;
Signed-off-by: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
[mpe: Trim / format change log]
Tested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc/nohash: fix pte_access_permitted()</title>
<updated>2018-09-09T08:32:31Z</updated>
<author>
<name>Christophe Leroy</name>
</author>
<published>2018-08-21T13:03:23Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=d4e41dc984f2d6899b6cdc35eafa9cd55ae287f5'/>
<id>urn:sha1:d4e41dc984f2d6899b6cdc35eafa9cd55ae287f5</id>
<content type='text'>
commit 810e9f86f36f59f1d6f6710220c49afe0c705f38 upstream.

Commit 5769beaf180a8 ("powerpc/mm: Add proper pte access check helper
for other platforms") replaced generic pte_access_permitted() by an
arch specific one.

The generic one is defined as
(pte_present(pte) &amp;&amp; (!(write) || pte_write(pte)))

The arch specific one is open coded checking that _PAGE_USER and
_PAGE_WRITE (_PAGE_RW) flags are set, but lacking to check that
_PAGE_RO and _PAGE_PRIVILEGED are unset, leading to a useless test
on targets like the 8xx which defines _PAGE_RW and _PAGE_USER as 0.

Commit 5fa5b16be5b31 ("powerpc/mm/hugetlb: Use pte_access_permitted
for hugetlb access check") replaced some tests performed with
pte helpers by a call to pte_access_permitted(), leading to the same
issue.

This patch rewrites powerpc/nohash pte_access_permitted()
using pte helpers.

Fixes: 5769beaf180a8 ("powerpc/mm: Add proper pte access check helper for other platforms")
Fixes: 5fa5b16be5b31 ("powerpc/mm/hugetlb: Use pte_access_permitted for hugetlb access check")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Reviewed-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>powerpc/pkeys: key allocation/deallocation must not change pkey registers</title>
<updated>2018-09-09T08:32:30Z</updated>
<author>
<name>Ram Pai</name>
</author>
<published>2018-07-17T13:51:04Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=0d86f534567280bc801083e9783c97da5ee18c64'/>
<id>urn:sha1:0d86f534567280bc801083e9783c97da5ee18c64</id>
<content type='text'>
commit 4a4a5e5d2aadc793be95024f454cf511d115b62d upstream.

Key allocation and deallocation has the side effect of programming the
UAMOR/AMR/IAMR registers. This is wrong, since its the responsibility of
the application and not that of the kernel, to modify the permission on
the key.

Do not modify the pkey registers at key allocation/deallocation.

This patch also fixes a bug where a sys_pkey_free() resets the UAMOR
bits of the key, thus making its permissions unmodifiable from user
space. Later if the same key gets reallocated from a different thread
this thread will no longer be able to change the permissions on the key.

Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Reviewed-by: Thiago Jung Bauermann &lt;bauerman@linux.ibm.com&gt;
Signed-off-by: Ram Pai &lt;linuxram@us.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>powerpc/fadump: handle crash memory ranges array index overflow</title>
<updated>2018-09-09T08:32:30Z</updated>
<author>
<name>Hari Bathini</name>
</author>
<published>2018-08-06T20:42:45Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7c0850fb2b60d2f1bc7580b273021aea10a9aec1'/>
<id>urn:sha1:7c0850fb2b60d2f1bc7580b273021aea10a9aec1</id>
<content type='text'>
commit 1bd6a1c4b80a28d975287630644e6b47d0f977a5 upstream.

Crash memory ranges is an array of memory ranges of the crashing kernel
to be exported as a dump via /proc/vmcore file. The size of the array
is set based on INIT_MEMBLOCK_REGIONS, which works alright in most cases
where memblock memory regions count is less than INIT_MEMBLOCK_REGIONS
value. But this count can grow beyond INIT_MEMBLOCK_REGIONS value since
commit 142b45a72e22 ("memblock: Add array resizing support").

On large memory systems with a few DLPAR operations, the memblock memory
regions count could be larger than INIT_MEMBLOCK_REGIONS value. On such
systems, registering fadump results in crash or other system failures
like below:

  task: c00007f39a290010 ti: c00000000b738000 task.ti: c00000000b738000
  NIP: c000000000047df4 LR: c0000000000f9e58 CTR: c00000000010f180
  REGS: c00000000b73b570 TRAP: 0300   Tainted: G          L   X  (4.4.140+)
  MSR: 8000000000009033 &lt;SF,EE,ME,IR,DR,RI,LE&gt;  CR: 22004484  XER: 20000000
  CFAR: c000000000008500 DAR: 000007a450000000 DSISR: 40000000 SOFTE: 0
  ...
  NIP [c000000000047df4] smp_send_reschedule+0x24/0x80
  LR [c0000000000f9e58] resched_curr+0x138/0x160
  Call Trace:
    resched_curr+0x138/0x160 (unreliable)
    check_preempt_curr+0xc8/0xf0
    ttwu_do_wakeup+0x38/0x150
    try_to_wake_up+0x224/0x4d0
    __wake_up_common+0x94/0x100
    ep_poll_callback+0xac/0x1c0
    __wake_up_common+0x94/0x100
    __wake_up_sync_key+0x70/0xa0
    sock_def_readable+0x58/0xa0
    unix_stream_sendmsg+0x2dc/0x4c0
    sock_sendmsg+0x68/0xa0
    ___sys_sendmsg+0x2cc/0x2e0
    __sys_sendmsg+0x5c/0xc0
    SyS_socketcall+0x36c/0x3f0
    system_call+0x3c/0x100

as array index overflow is not checked for while setting up crash memory
ranges causing memory corruption. To resolve this issue, dynamically
allocate memory for crash memory ranges and resize it incrementally,
in units of pagesize, on hitting array size limit.

Fixes: 2df173d9e85d ("fadump: Initialize elfcore header and add PT_LOAD program headers.")
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Hari Bathini &lt;hbathini@linux.ibm.com&gt;
Reviewed-by: Mahesh Salgaonkar &lt;mahesh@linux.vnet.ibm.com&gt;
[mpe: Just use PAGE_SIZE directly, fixup variable placement]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
