<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/arch/powerpc/platforms/pseries, branch linus/master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/arch/powerpc/platforms/pseries?h=linus%2Fmaster</id>
<link rel='self' href='https://git.zx2c4.com/linux-dev/atom/arch/powerpc/platforms/pseries?h=linus%2Fmaster'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/'/>
<updated>2022-05-31T00:18:52Z</updated>
<entry>
<title>powerpc/papr_scm: don't requests stats with '0' sized stats buffer</title>
<updated>2022-05-31T00:18:52Z</updated>
<author>
<name>Vaibhav Jain</name>
<email>vaibhav@linux.ibm.com</email>
</author>
<published>2022-05-24T11:23:53Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=07bf9431b1590d1cd7a8d62075d0b50b073f0495'/>
<id>urn:sha1:07bf9431b1590d1cd7a8d62075d0b50b073f0495</id>
<content type='text'>
Sachin reported [1] that on a POWER-10 lpar he is seeing a kernel panic being
reported with vPMEM when papr_scm probe is being called. The panic is of the
form below and is observed only with following option disabled(profile) for the
said LPAR 'Enable Performance Information Collection' in the HMC:

 Kernel attempted to write user page (1c) - exploit attempt? (uid: 0)
 BUG: Kernel NULL pointer dereference on write at 0x0000001c
 Faulting instruction address: 0xc008000001b90844
 Oops: Kernel access of bad area, sig: 11 [#1]
&lt;snip&gt;
 NIP [c008000001b90844] drc_pmem_query_stats+0x5c/0x270 [papr_scm]
 LR [c008000001b92794] papr_scm_probe+0x2ac/0x6ec [papr_scm]
 Call Trace:
       0xc00000000941bca0 (unreliable)
       papr_scm_probe+0x2ac/0x6ec [papr_scm]
       platform_probe+0x98/0x150
       really_probe+0xfc/0x510
       __driver_probe_device+0x17c/0x230
&lt;snip&gt;
 ---[ end trace 0000000000000000 ]---
 Kernel panic - not syncing: Fatal exception

On investigation looks like this panic was caused due to a 'stat_buffer' of
size==0 being provided to drc_pmem_query_stats() to fetch all performance
stats-ids of an NVDIMM. However drc_pmem_query_stats() shouldn't have been called
since the vPMEM NVDIMM doesn't support and performance stat-id's. This was caused
due to missing check for 'p-&gt;stat_buffer_len' at the beginning of
papr_scm_pmu_check_events() which indicates that the NVDIMM doesn't support
performance-stats.

Fix this by introducing the check for 'p-&gt;stat_buffer_len' at the beginning of
papr_scm_pmu_check_events().

[1] https://lore.kernel.org/all/6B3A522A-6A5F-4CC9-B268-0C63AA6E07D3@linux.ibm.com

Fixes: 0e0946e22f3665d2732 ("powerpc/papr_scm: Fix leaking nvdimm_events_map elements")
Reported-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Signed-off-by: Vaibhav Jain &lt;vaibhav@linux.ibm.com&gt;
Tested-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220524112353.1718454-1-vaibhav@linux.ibm.com

</content>
</entry>
<entry>
<title>Merge tag 'powerpc-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2022-05-28T18:27:17Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-28T18:27:17Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=6112bd00e84e5dbffebc3c1e908cbe914ca772ee'/>
<id>urn:sha1:6112bd00e84e5dbffebc3c1e908cbe914ca772ee</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Convert to the generic mmap support (ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)

 - Add support for outline-only KASAN with 64-bit Radix MMU (P9 or later)

 - Increase SIGSTKSZ and MINSIGSTKSZ and add support for AT_MINSIGSTKSZ

 - Enable the DAWR (Data Address Watchpoint) on POWER9 DD2.3 or later

 - Drop support for system call instruction emulation

 - Many other small features and fixes

Thanks to Alexey Kardashevskiy, Alistair Popple, Andy Shevchenko, Bagas
Sanjaya, Bjorn Helgaas, Bo Liu, Chen Huang, Christophe Leroy, Colin Ian
King, Daniel Axtens, Dwaipayan Ray, Fabiano Rosas, Finn Thain, Frank
Rowand, Fuqian Huang, Guilherme G. Piccoli, Hangyu Hua, Haowen Bai,
Haren Myneni, Hari Bathini, He Ying, Jason Wang, Jiapeng Chong, Jing
Yangyang, Joel Stanley, Julia Lawall, Kajol Jain, Kevin Hao, Krzysztof
Kozlowski, Laurent Dufour, Lv Ruyi, Madhavan Srinivasan, Magali Lemes,
Miaoqian Lin, Minghao Chi, Nathan Chancellor, Naveen N. Rao, Nicholas
Piggin, Oliver O'Halloran, Oscar Salvador, Pali Rohár, Paul Mackerras,
Peng Wu, Qing Wang, Randy Dunlap, Reza Arbab, Russell Currey, Sohaib
Mohamed, Vaibhav Jain, Vasant Hegde, Wang Qing, Wang Wensheng, Xiang
wangx, Xiaomeng Tong, Xu Wang, Yang Guang, Yang Li, Ye Bin, YueHaibing,
Yu Kuai, Zheng Bin, Zou Wei, and Zucheng Zheng.

* tag 'powerpc-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (200 commits)
  powerpc/64: Include cache.h directly in paca.h
  powerpc/64s: Only set HAVE_ARCH_UNMAPPED_AREA when CONFIG_PPC_64S_HASH_MMU is set
  powerpc/xics: Include missing header
  powerpc/powernv/pci: Drop VF MPS fixup
  powerpc/fsl_book3e: Don't set rodata RO too early
  powerpc/microwatt: Add mmu bits to device tree
  powerpc/powernv/flash: Check OPAL flash calls exist before using
  powerpc/powermac: constify device_node in of_irq_parse_oldworld()
  powerpc/powermac: add missing g5_phy_disable_cpu1() declaration
  selftests/powerpc/pmu: fix spelling mistake "mis-match" -&gt; "mismatch"
  powerpc: Enable the DAWR on POWER9 DD2.3 and above
  powerpc/64s: Add CPU_FTRS_POWER10 to ALWAYS mask
  powerpc/64s: Add CPU_FTRS_POWER9_DD2_2 to CPU_FTRS_ALWAYS mask
  powerpc: Fix all occurences of "the the"
  selftests/powerpc/pmu/ebb: remove fixed_instruction.S
  powerpc/platforms/83xx: Use of_device_get_match_data()
  powerpc/eeh: Drop redundant spinlock initialization
  powerpc/iommu: Add missing of_node_put in iommu_init_early_dart
  powerpc/pseries/vas: Call misc_deregister if sysfs init fails
  powerpc/papr_scm: Fix leaking nvdimm_events_map elements
  ...
</content>
</entry>
<entry>
<title>Merge tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping</title>
<updated>2022-05-26T02:18:36Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-26T02:18:36Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=3f306ea2e18568f693f7763d1c2178f349ae8f31'/>
<id>urn:sha1:3f306ea2e18568f693f7763d1c2178f349ae8f31</id>
<content type='text'>
Pull dma-mapping updates from Christoph Hellwig:

 - don't over-decrypt memory (Robin Murphy)

 - takes min align mask into account for the swiotlb max mapping size
   (Tianyu Lan)

 - use GFP_ATOMIC in dma-debug (Mikulas Patocka)

 - fix DMA_ATTR_NO_KERNEL_MAPPING on xen/arm (me)

 - don't fail on highmem CMA pages in dma_direct_alloc_pages (me)

 - cleanup swiotlb initialization and share more code with swiotlb-xen
   (me, Stefano Stabellini)

* tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping: (23 commits)
  dma-direct: don't over-decrypt memory
  swiotlb: max mapping size takes min align mask into account
  swiotlb: use the right nslabs-derived sizes in swiotlb_init_late
  swiotlb: use the right nslabs value in swiotlb_init_remap
  swiotlb: don't panic when the swiotlb buffer can't be allocated
  dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC
  dma-direct: don't fail on highmem CMA pages in dma_direct_alloc_pages
  swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm
  x86: remove cruft from &lt;asm/dma-mapping.h&gt;
  swiotlb: remove swiotlb_init_with_tbl and swiotlb_init_late_with_tbl
  swiotlb: merge swiotlb-xen initialization into swiotlb
  swiotlb: provide swiotlb_init variants that remap the buffer
  swiotlb: pass a gfp_mask argument to swiotlb_init_late
  swiotlb: add a SWIOTLB_ANY flag to lift the low memory restriction
  swiotlb: make the swiotlb_init interface more useful
  x86: centralize setting SWIOTLB_FORCE when guest memory encryption is enabled
  x86: remove the IOMMU table infrastructure
  MIPS/octeon: use swiotlb_init instead of open coding it
  arm/xen: don't check for xen_initial_domain() in xen_create_contiguous_region
  swiotlb: rename swiotlb_late_init_with_default_size
  ...
</content>
</entry>
<entry>
<title>powerpc/eeh: Drop redundant spinlock initialization</title>
<updated>2022-05-22T05:58:31Z</updated>
<author>
<name>Haowen Bai</name>
<email>baihaowen@meizu.com</email>
</author>
<published>2022-05-11T01:27:56Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=3def164a5cedad9117859dd4610cae2cc59cb6d2'/>
<id>urn:sha1:3def164a5cedad9117859dd4610cae2cc59cb6d2</id>
<content type='text'>
slot_errbuf_lock has declared and initialized by DEFINE_SPINLOCK,
so we don't need to spin_lock_init again, drop it.

Signed-off-by: Haowen Bai &lt;baihaowen@meizu.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/1652232476-9696-1-git-send-email-baihaowen@meizu.com

</content>
</entry>
<entry>
<title>powerpc/pseries/vas: Call misc_deregister if sysfs init fails</title>
<updated>2022-05-22T05:58:31Z</updated>
<author>
<name>Zheng Bin</name>
<email>zhengbin13@huawei.com</email>
</author>
<published>2022-05-11T03:35:07Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=426e5805226358dbe9af233347c5bf3c81f2125c'/>
<id>urn:sha1:426e5805226358dbe9af233347c5bf3c81f2125c</id>
<content type='text'>
Undo effects of misc_register if sysfs init fails after
misc_register.

Signed-off-by: Zheng Bin &lt;zhengbin13@huawei.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220511033507.2745992-1-zhengbin13@huawei.com

</content>
</entry>
<entry>
<title>powerpc/papr_scm: Fix leaking nvdimm_events_map elements</title>
<updated>2022-05-22T05:58:31Z</updated>
<author>
<name>Vaibhav Jain</name>
<email>vaibhav@linux.ibm.com</email>
</author>
<published>2022-05-11T08:26:36Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=0e0946e22f3665d27325d389ff45ade6e93f3678'/>
<id>urn:sha1:0e0946e22f3665d27325d389ff45ade6e93f3678</id>
<content type='text'>
Right now 'char *' elements allocated for individual 'stat_id' in
'papr_scm_priv.nvdimm_events_map[]' during papr_scm_pmu_check_events(), get
leaked in papr_scm_remove() and papr_scm_pmu_register(),
papr_scm_pmu_check_events() error paths.

Also individual 'stat_id' arent NULL terminated 'char *' instead they are fixed
8-byte sized identifiers. However papr_scm_pmu_register() assumes it to be a
NULL terminated 'char *' and at other places it assumes it to be a
'papr_scm_perf_stat.stat_id' sized string which is 8-byes in size.

Fix this by allocating the memory for papr_scm_priv.nvdimm_events_map to also
include space for 'stat_id' entries. This is possible since number of available
events/stat_ids are known upfront. This saves some memory and one extra level of
indirection from 'nvdimm_events_map' to 'stat_id'. Also rest of the code
can continue to call 'kfree(papr_scm_priv.nvdimm_events_map)' without needing to
iterate over the array and free up individual elements.

Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support")
Signed-off-by: Vaibhav Jain &lt;vaibhav@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220511082637.646714-1-vaibhav@linux.ibm.com

</content>
</entry>
<entry>
<title>powerpc/numa: Associate numa node to its cpu earlier</title>
<updated>2022-05-22T05:58:30Z</updated>
<author>
<name>Oscar Salvador</name>
<email>osalvador@suse.de</email>
</author>
<published>2022-04-11T07:49:34Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=48b63961c84671df4c4a4451c40057e34b26df1a'/>
<id>urn:sha1:48b63961c84671df4c4a4451c40057e34b26df1a</id>
<content type='text'>
powerpc is the only platform that do not rely on
cpu_up()-&gt;try_online_node() to bring up a numa node,
and special cases it, instead, deep in its own machinery:

dlpar_online_cpu
 find_and_online_cpu_nid
  try_online_node

This should not be needed, but the thing is that the try_online_node()
from cpu_up() will not apply on the right node, because cpu_to_node()
will return the old mapping numa&lt;-&gt;cpu that gets set on boot stage
for all possible cpus.

That can be seen easily if we try to print out the numa node passed
to try_online_node() in cpu_up().

The thing is that the numa&lt;-&gt;cpu mapping does not get updated till a much
later stage in start_secondary:

start_secondary:
 set_numa_node(numa_cpu_lookup_table[cpu])

But we do not really care, as we already now the
CPU &lt;-&gt; NUMA associativity back in find_and_online_cpu_nid(),
so let us make use of that and set the proper numa&lt;-&gt;cpu mapping,
so cpu_to_node() in cpu_up() returns the right node and
try_online_node() can do its work.

Signed-off-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Tested-by: Geetika Moolchandani &lt;Geetika.Moolchandani1@ibm.com&gt;
Reviewed-by: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220411074934.4632-1-osalvador@suse.de

</content>
</entry>
<entry>
<title>powerpc: Book3S 64-bit outline-only KASAN support</title>
<updated>2022-05-22T05:58:29Z</updated>
<author>
<name>Daniel Axtens</name>
<email>dja@axtens.net</email>
</author>
<published>2022-05-18T10:05:31Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=41b7a347bf1491e7300563bb224432608b41f62a'/>
<id>urn:sha1:41b7a347bf1491e7300563bb224432608b41f62a</id>
<content type='text'>
Implement a limited form of KASAN for Book3S 64-bit machines running under
the Radix MMU, supporting only outline mode.

 - Enable the compiler instrumentation to check addresses and maintain the
   shadow region. (This is the guts of KASAN which we can easily reuse.)

 - Require kasan-vmalloc support to handle modules and anything else in
   vmalloc space.

 - KASAN needs to be able to validate all pointer accesses, but we can't
   instrument all kernel addresses - only linear map and vmalloc. On boot,
   set up a single page of read-only shadow that marks all iomap and
   vmemmap accesses as valid.

 - Document KASAN in powerpc docs.

Background
----------

KASAN support on Book3S is a bit tricky to get right:

 - It would be good to support inline instrumentation so as to be able to
   catch stack issues that cannot be caught with outline mode.

 - Inline instrumentation requires a fixed offset.

 - Book3S runs code with translations off ("real mode") during boot,
   including a lot of generic device-tree parsing code which is used to
   determine MMU features.

    [ppc64 mm note: The kernel installs a linear mapping at effective
    address c000...-c008.... This is a one-to-one mapping with physical
    memory from 0000... onward. Because of how memory accesses work on
    powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the
    same memory both with translations on (accessing as an 'effective
    address'), and with translations off (accessing as a 'real
    address'). This works in both guests and the hypervisor. For more
    details, see s5.7 of Book III of version 3 of the ISA, in particular
    the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this
    KASAN implementation currently only supports Radix.]

 - Some code - most notably a lot of KVM code - also runs with translations
   off after boot.

 - Therefore any offset has to point to memory that is valid with
   translations on or off.

One approach is just to give up on inline instrumentation. This way
boot-time checks can be delayed until after the MMU is set is up, and we
can just not instrument any code that runs with translations off after
booting. Take this approach for now and require outline instrumentation.

Previous attempts allowed inline instrumentation. However, they came with
some unfortunate restrictions: only physically contiguous memory could be
used and it had to be specified at compile time. Maybe we can do better in
the future.

[paulus@ozlabs.org - Rebased onto 5.17.  Note that a kernel with
 CONFIG_KASAN=y will crash during boot on a machine using HPT
 translation because not all the entry points to the generic
 KASAN code are protected with a call to kasan_arch_is_ready().]

Originally-by: Balbir Singh &lt;bsingharora@gmail.com&gt; # ppc64 out-of-line radix version
Signed-off-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
[mpe: Update copyright year and comment formatting]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo

</content>
</entry>
<entry>
<title>powerpc/kasan: Disable address sanitization in kexec paths</title>
<updated>2022-05-22T05:58:29Z</updated>
<author>
<name>Daniel Axtens</name>
<email>dja@axtens.net</email>
</author>
<published>2022-05-18T10:07:05Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=2ab2d5794f14c08676690bf0859f16cc768bb3a4'/>
<id>urn:sha1:2ab2d5794f14c08676690bf0859f16cc768bb3a4</id>
<content type='text'>
The kexec code paths involve code that necessarily run in real mode, as
CPUs are disabled and control is transferred to the new kernel. Disable
address sanitization for the kexec code and the functions called in real
mode on CPUs being disabled.

[paulus@ozlabs.org: combined a few work-in-progress commits of
 Daniel's and wrote the commit message.]

Signed-off-by: Daniel Axtens &lt;dja@axtens.net&gt;
Signed-off-by: Paul Mackerras &lt;paulus@ozlabs.org&gt;
[mpe: Move pseries_machine_kexec() into kexec.c so setup.c can be instrumented]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/YoTFSQ2TUSEaDdVC@cleo

</content>
</entry>
<entry>
<title>powerpc/pseries/vas: sysfs comments with the correct entries</title>
<updated>2022-05-22T05:58:27Z</updated>
<author>
<name>Haren Myneni</name>
<email>haren@linux.ibm.com</email>
</author>
<published>2022-04-09T08:46:15Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=657ac633302b9d694958a82654363cb559277759'/>
<id>urn:sha1:657ac633302b9d694958a82654363cb559277759</id>
<content type='text'>
VAS entry is created as a misc device and the sysfs comments
should list the proper entries

Reported-by: Matheus Castanho &lt;mscastanho@ibm.com&gt;
Signed-off-by: Haren Myneni &lt;haren@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/6dee950c7b72a4965c102208041f14a063cf5a8c.camel@linux.ibm.com

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