<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/linux/mm.h, branch v6.12-rc4</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>mm: fix build on 32-bit targets without MAX_PHYSMEM_BITS</title>
<updated>2024-09-23T15:58:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-23T15:58:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f8eb5bd9a818cc5f2a1e50b22b0091830b28cc36'/>
<id>f8eb5bd9a818cc5f2a1e50b22b0091830b28cc36</id>
<content type='text'>
The merge resolution to deal with the conflict between commits
ea72ce5da228 ("x86/kaslr: Expose and use the end of the physical memory
address space") and 99185c10d5d9 ("resource, kunit: add test case for
region_intersects()") ended up being broken in configurations didn't
define a MAX_PHYSMEM_BITS and that had a 32-bit 'phys_addr_t'.

The fallback to using all bits set (ie "(-1ULL)") ended up causing a
build error:

    kernel/resource.c: In function ‘gfr_start’:
    include/linux/minmax.h:93:30: error: conversion from ‘long long unsigned int’ to ‘resource_size_t’ {aka ‘unsigned int’} changes value from ‘18446744073709551615’ to ‘4294967295’ [-Werror=overflow]

this was reported by Geert for m68k, but he points out that it happens
on other 32-bit architectures too, eg mips, xtensa, parisc, and powerpc.

Limiting 'PHYSMEM_END' to a 'phys_addr_t' (which is the same as
'resource_size_t') fixes the build, but Geert points out that it will
then cause a silent overflow in mm/sparse.c:

	unsigned long max_sparsemem_pfn = (PHYSMEM_END + 1) &gt;&gt; PAGE_SHIFT;

so we actually do want PHYSMEM_END to be defined a 64-bit type - just
not all ones, and not larger than 'phys_addr_t'.

The proper fix is probably to not have some kind of default fallback at
all, but just make sure every architecture has a valid MAX_PHYSMEM_BITS.
But in the meantime, this just applies the rule that PHYSMEM_END is the
largest value that fits in a 'phys_addr_t', but does not have the high
bit set in 64 bits.

Ugly, ugly.

Reported-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Huang Ying &lt;ying.huang@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The merge resolution to deal with the conflict between commits
ea72ce5da228 ("x86/kaslr: Expose and use the end of the physical memory
address space") and 99185c10d5d9 ("resource, kunit: add test case for
region_intersects()") ended up being broken in configurations didn't
define a MAX_PHYSMEM_BITS and that had a 32-bit 'phys_addr_t'.

The fallback to using all bits set (ie "(-1ULL)") ended up causing a
build error:

    kernel/resource.c: In function ‘gfr_start’:
    include/linux/minmax.h:93:30: error: conversion from ‘long long unsigned int’ to ‘resource_size_t’ {aka ‘unsigned int’} changes value from ‘18446744073709551615’ to ‘4294967295’ [-Werror=overflow]

this was reported by Geert for m68k, but he points out that it happens
on other 32-bit architectures too, eg mips, xtensa, parisc, and powerpc.

Limiting 'PHYSMEM_END' to a 'phys_addr_t' (which is the same as
'resource_size_t') fixes the build, but Geert points out that it will
then cause a silent overflow in mm/sparse.c:

	unsigned long max_sparsemem_pfn = (PHYSMEM_END + 1) &gt;&gt; PAGE_SHIFT;

so we actually do want PHYSMEM_END to be defined a 64-bit type - just
not all ones, and not larger than 'phys_addr_t'.

The proper fix is probably to not have some kind of default fallback at
all, but just make sure every architecture has a valid MAX_PHYSMEM_BITS.
But in the meantime, this just applies the rule that PHYSMEM_END is the
largest value that fits in a 'phys_addr_t', but does not have the high
bit set in 64 bits.

Ugly, ugly.

Reported-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Huang Ying &lt;ying.huang@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2024-09-21T14:29:05+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-21T14:29:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=617a814f14b8914271f7a70366d72c6196d17663'/>
<id>617a814f14b8914271f7a70366d72c6196d17663</id>
<content type='text'>
Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area-&gt;pages[2] into xol_area-&gt;page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area-&gt;pages[2] into xol_area-&gt;page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'random-6.12-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random</title>
<updated>2024-09-18T13:26:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-18T13:26:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4a39ac5b7d62679c07a3e3d12b0f6982377d8a7d'/>
<id>4a39ac5b7d62679c07a3e3d12b0f6982377d8a7d</id>
<content type='text'>
Pull random number generator updates from Jason Donenfeld:
 "Originally I'd planned on sending each of the vDSO getrandom()
  architecture ports to their respective arch trees. But as we started
  to work on this, we found lots of interesting issues in the shared
  code and infrastructure, the fixes for which the various archs needed
  to base their work.

  So in the end, this turned into a nice collaborative effort fixing up
  issues and porting to 5 new architectures -- arm64, powerpc64,
  powerpc32, s390x, and loongarch64 -- with everybody pitching in and
  commenting on each other's code. It was a fun development cycle.

  This contains:

   - Numerous fixups to the vDSO selftest infrastructure, getting it
     running successfully on more platforms, and fixing bugs in it.

   - Additions to the vDSO getrandom &amp; chacha selftests. Basically every
     time manual review unearthed a bug in a revision of an arch patch,
     or an ambiguity, the tests were augmented.

     By the time the last arch was submitted for review, s390x, v1 of
     the series was essentially fine right out of the gate.

   - Fixes to the the generic C implementation of vDSO getrandom, to
     build and run successfully on all archs, decoupling it from
     assumptions we had (unintentionally) made on x86_64 that didn't
     carry through to the other architectures.

   - Port of vDSO getrandom to LoongArch64, from Xi Ruoyao and acked by
     Huacai Chen.

   - Port of vDSO getrandom to ARM64, from Adhemerval Zanella and acked
     by Will Deacon.

   - Port of vDSO getrandom to PowerPC, in both 32-bit and 64-bit
     varieties, from Christophe Leroy and acked by Michael Ellerman.

   - Port of vDSO getrandom to S390X from Heiko Carstens, the arch
     maintainer.

  While it'd be natural for there to be things to fix up over the course
  of the development cycle, these patches got a decent amount of review
  from a fairly diverse crew of folks on the mailing lists, and, for the
  most part, they've been cooking in linux-next, which has been helpful
  for ironing out build issues.

  In terms of architectures, I think that mostly takes care of the
  important 64-bit archs with hardware still being produced and running
  production loads in settings where vDSO getrandom is likely to help.

  Arguably there's still RISC-V left, and we'll see for 6.13 whether
  they find it useful and submit a port"

* tag 'random-6.12-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (47 commits)
  selftests: vDSO: check cpu caps before running chacha test
  s390/vdso: Wire up getrandom() vdso implementation
  s390/vdso: Move vdso symbol handling to separate header file
  s390/vdso: Allow alternatives in vdso code
  s390/module: Provide find_section() helper
  s390/facility: Let test_facility() generate static branch if possible
  s390/alternatives: Remove ALT_FACILITY_EARLY
  s390/facility: Disable compile time optimization for decompressor code
  selftests: vDSO: fix vdso_config for s390
  selftests: vDSO: fix ELF hash table entry size for s390x
  powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64
  powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32
  powerpc/vdso: Refactor CFLAGS for CVDSO build
  powerpc/vdso32: Add crtsavres
  mm: Define VM_DROPPABLE for powerpc/32
  powerpc/vdso: Fix VDSO data access when running in a non-root time namespace
  selftests: vDSO: don't include generated headers for chacha test
  arm64: vDSO: Wire up getrandom() vDSO implementation
  arm64: alternative: make alternative_has_cap_likely() VDSO compatible
  selftests: vDSO: also test counter in vdso_test_chacha
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull random number generator updates from Jason Donenfeld:
 "Originally I'd planned on sending each of the vDSO getrandom()
  architecture ports to their respective arch trees. But as we started
  to work on this, we found lots of interesting issues in the shared
  code and infrastructure, the fixes for which the various archs needed
  to base their work.

  So in the end, this turned into a nice collaborative effort fixing up
  issues and porting to 5 new architectures -- arm64, powerpc64,
  powerpc32, s390x, and loongarch64 -- with everybody pitching in and
  commenting on each other's code. It was a fun development cycle.

  This contains:

   - Numerous fixups to the vDSO selftest infrastructure, getting it
     running successfully on more platforms, and fixing bugs in it.

   - Additions to the vDSO getrandom &amp; chacha selftests. Basically every
     time manual review unearthed a bug in a revision of an arch patch,
     or an ambiguity, the tests were augmented.

     By the time the last arch was submitted for review, s390x, v1 of
     the series was essentially fine right out of the gate.

   - Fixes to the the generic C implementation of vDSO getrandom, to
     build and run successfully on all archs, decoupling it from
     assumptions we had (unintentionally) made on x86_64 that didn't
     carry through to the other architectures.

   - Port of vDSO getrandom to LoongArch64, from Xi Ruoyao and acked by
     Huacai Chen.

   - Port of vDSO getrandom to ARM64, from Adhemerval Zanella and acked
     by Will Deacon.

   - Port of vDSO getrandom to PowerPC, in both 32-bit and 64-bit
     varieties, from Christophe Leroy and acked by Michael Ellerman.

   - Port of vDSO getrandom to S390X from Heiko Carstens, the arch
     maintainer.

  While it'd be natural for there to be things to fix up over the course
  of the development cycle, these patches got a decent amount of review
  from a fairly diverse crew of folks on the mailing lists, and, for the
  most part, they've been cooking in linux-next, which has been helpful
  for ironing out build issues.

  In terms of architectures, I think that mostly takes care of the
  important 64-bit archs with hardware still being produced and running
  production loads in settings where vDSO getrandom is likely to help.

  Arguably there's still RISC-V left, and we'll see for 6.13 whether
  they find it useful and submit a port"

* tag 'random-6.12-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (47 commits)
  selftests: vDSO: check cpu caps before running chacha test
  s390/vdso: Wire up getrandom() vdso implementation
  s390/vdso: Move vdso symbol handling to separate header file
  s390/vdso: Allow alternatives in vdso code
  s390/module: Provide find_section() helper
  s390/facility: Let test_facility() generate static branch if possible
  s390/alternatives: Remove ALT_FACILITY_EARLY
  s390/facility: Disable compile time optimization for decompressor code
  selftests: vDSO: fix vdso_config for s390
  selftests: vDSO: fix ELF hash table entry size for s390x
  powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64
  powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32
  powerpc/vdso: Refactor CFLAGS for CVDSO build
  powerpc/vdso32: Add crtsavres
  mm: Define VM_DROPPABLE for powerpc/32
  powerpc/vdso: Fix VDSO data access when running in a non-root time namespace
  selftests: vDSO: don't include generated headers for chacha test
  arm64: vDSO: Wire up getrandom() vDSO implementation
  arm64: alternative: make alternative_has_cap_likely() VDSO compatible
  selftests: vDSO: also test counter in vdso_test_chacha
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'execve-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux</title>
<updated>2024-09-18T09:53:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-18T09:53:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=667495de218c25e909c6b33ed647b592a8a71a02'/>
<id>667495de218c25e909c6b33ed647b592a8a71a02</id>
<content type='text'>
Pull execve updates from Kees Cook:

 - binfmt_elf: Dump smaller VMAs first in ELF cores (Brian Mak)

 - binfmt_elf: mseal address zero (Jeff Xu)

 - binfmt_elf, coredump: Log the reason of the failed core dumps (Roman
   Kisel)

* tag 'execve-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  binfmt_elf: mseal address zero
  binfmt_elf: Dump smaller VMAs first in ELF cores
  binfmt_elf, coredump: Log the reason of the failed core dumps
  coredump: Standartize and fix logging
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull execve updates from Kees Cook:

 - binfmt_elf: Dump smaller VMAs first in ELF cores (Brian Mak)

 - binfmt_elf: mseal address zero (Jeff Xu)

 - binfmt_elf, coredump: Log the reason of the failed core dumps (Roman
   Kisel)

* tag 'execve-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  binfmt_elf: mseal address zero
  binfmt_elf: Dump smaller VMAs first in ELF cores
  binfmt_elf, coredump: Log the reason of the failed core dumps
  coredump: Standartize and fix logging
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: remove follow_pte()</title>
<updated>2024-09-17T08:06:59+00:00</updated>
<author>
<name>Peter Xu</name>
<email>peterx@redhat.com</email>
</author>
<published>2024-08-26T20:43:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b0a1c0d0edcd75a0f8ec5fd19dbd64b8d097f534'/>
<id>b0a1c0d0edcd75a0f8ec5fd19dbd64b8d097f534</id>
<content type='text'>
follow_pte() users have been converted to follow_pfnmap*().  Remove the
API.

Link: https://lkml.kernel.org/r/20240826204353.2228736-17-peterx@redhat.com
Signed-off-by: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Gavin Shan &lt;gshan@redhat.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
follow_pte() users have been converted to follow_pfnmap*().  Remove the
API.

Link: https://lkml.kernel.org/r/20240826204353.2228736-17-peterx@redhat.com
Signed-off-by: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Gavin Shan &lt;gshan@redhat.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: new follow_pfnmap API</title>
<updated>2024-09-17T08:06:59+00:00</updated>
<author>
<name>Peter Xu</name>
<email>peterx@redhat.com</email>
</author>
<published>2024-08-26T20:43:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6da8e9634bb7e3fdad9ae0e4db873a05036c4343'/>
<id>6da8e9634bb7e3fdad9ae0e4db873a05036c4343</id>
<content type='text'>
Introduce a pair of APIs to follow pfn mappings to get entry information. 
It's very similar to what follow_pte() does before, but different in that
it recognizes huge pfn mappings.

Link: https://lkml.kernel.org/r/20240826204353.2228736-10-peterx@redhat.com
Signed-off-by: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Gavin Shan &lt;gshan@redhat.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce a pair of APIs to follow pfn mappings to get entry information. 
It's very similar to what follow_pte() does before, but different in that
it recognizes huge pfn mappings.

Link: https://lkml.kernel.org/r/20240826204353.2228736-10-peterx@redhat.com
Signed-off-by: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Gavin Shan &lt;gshan@redhat.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: introduce ARCH_SUPPORTS_HUGE_PFNMAP and special bits to pmd/pud</title>
<updated>2024-09-17T08:06:58+00:00</updated>
<author>
<name>Peter Xu</name>
<email>peterx@redhat.com</email>
</author>
<published>2024-08-26T20:43:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6857be5fecaebd9773ff27b6d29b6fff3b1abbce'/>
<id>6857be5fecaebd9773ff27b6d29b6fff3b1abbce</id>
<content type='text'>
Patch series "mm: Support huge pfnmaps", v2.

Overview
========

This series implements huge pfnmaps support for mm in general.  Huge
pfnmap allows e.g.  VM_PFNMAP vmas to map in either PMD or PUD levels,
similar to what we do with dax / thp / hugetlb so far to benefit from TLB
hits.  Now we extend that idea to PFN mappings, e.g.  PCI MMIO bars where
it can grow as large as 8GB or even bigger.

Currently, only x86_64 (1G+2M) and arm64 (2M) are supported.  The last
patch (from Alex Williamson) will be the first user of huge pfnmap, so as
to enable vfio-pci driver to fault in huge pfn mappings.

Implementation
==============

In reality, it's relatively simple to add such support comparing to many
other types of mappings, because of PFNMAP's specialties when there's no
vmemmap backing it, so that most of the kernel routines on huge mappings
should simply already fail for them, like GUPs or old-school follow_page()
(which is recently rewritten to be folio_walk* APIs by David).

One trick here is that we're still unmature on PUDs in generic paths here
and there, as DAX is so far the only user.  This patchset will add the 2nd
user of it.  Hugetlb can be a 3rd user if the hugetlb unification work can
go on smoothly, but to be discussed later.

The other trick is how to allow gup-fast working for such huge mappings
even if there's no direct sign of knowing whether it's a normal page or
MMIO mapping.  This series chose to keep the pte_special solution, so that
it reuses similar idea on setting a special bit to pfnmap PMDs/PUDs so
that gup-fast will be able to identify them and fail properly.

Along the way, we'll also notice that the major pgtable pfn walker, aka,
follow_pte(), will need to retire soon due to the fact that it only works
with ptes.  A new set of simple API is introduced (follow_pfnmap* API) to
be able to do whatever follow_pte() can already do, plus that it can also
process huge pfnmaps now.  Half of this series is about that and
converting all existing pfnmap walkers to use the new API properly. 
Hopefully the new API also looks better to avoid exposing e.g.  pgtable
lock details into the callers, so that it can be used in an even more
straightforward way.

Here, three more options will be introduced and involved in huge pfnmap:

  - ARCH_SUPPORTS_HUGE_PFNMAP

    Arch developers will need to select this option when huge pfnmap is
    supported in arch's Kconfig.  After this patchset applied, both x86_64
    and arm64 will start to enable it by default.

  - ARCH_SUPPORTS_PMD_PFNMAP / ARCH_SUPPORTS_PUD_PFNMAP

    These options are for driver developers to identify whether current
    arch / config supports huge pfnmaps, making decision on whether it can
    use the huge pfnmap APIs to inject them.  One can refer to the last
    vfio-pci patch from Alex on the use of them properly in a device
    driver.

So after the whole set applied, and if one would enable some dynamic debug
lines in vfio-pci core files, we should observe things like:

  vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x0: 0x100
  vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x200: 0x100
  vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x400: 0x100

In this specific case, it says that vfio-pci faults in PMDs properly for a
few BAR0 offsets.

Patch Layout
============

Patch 1:         Introduce the new options mentioned above for huge PFNMAPs
Patch 2:         A tiny cleanup
Patch 3-8:       Preparation patches for huge pfnmap (include introduce
                 special bit for pmd/pud)
Patch 9-16:      Introduce follow_pfnmap*() API, use it everywhere, and
                 then drop follow_pte() API
Patch 17:        Add huge pfnmap support for x86_64
Patch 18:        Add huge pfnmap support for arm64
Patch 19:        Add vfio-pci support for all kinds of huge pfnmaps (Alex)

TODO
====

More architectures / More page sizes
------------------------------------

Currently only x86_64 (2M+1G) and arm64 (2M) are supported.  There seems
to have plan to support arm64 1G later on top of this series [2].

Any arch will need to first support THP / THP_1G, then provide a special
bit in pmds/puds to support huge pfnmaps.

remap_pfn_range() support
-------------------------

Currently, remap_pfn_range() still only maps PTEs.  With the new option,
remap_pfn_range() can logically start to inject either PMDs or PUDs when
the alignment requirements match on the VAs.

When the support is there, it should be able to silently benefit all
drivers that is using remap_pfn_range() in its mmap() handler on better
TLB hit rate and overall faster MMIO accesses similar to processor on
hugepages.

More driver support
-------------------

VFIO is so far the only consumer for the huge pfnmaps after this series
applied.  Besides above remap_pfn_range() generic optimization, device
driver can also try to optimize its mmap() on a better VA alignment for
either PMD/PUD sizes.  This may, iiuc, normally require userspace changes,
as the driver doesn't normally decide the VA to map a bar.  But I don't
think I know all the drivers to know the full picture.

Credits all go to Alex on help testing the GPU/NIC use cases above.

[0] https://lore.kernel.org/r/73ad9540-3fb8-4154-9a4f-30a0a2b03d41@lucifer.local
[1] https://lore.kernel.org/r/20240807194812.819412-1-peterx@redhat.com
[2] https://lore.kernel.org/r/498e0731-81a4-4f75-95b4-a8ad0bcc7665@huawei.com


This patch (of 19):

This patch introduces the option to introduce special pte bit into
pmd/puds.  Archs can start to define pmd_special / pud_special when
supported by selecting the new option.  Per-arch support will be added
later.

Before that, create fallbacks for these helpers so that they are always
available.

Link: https://lkml.kernel.org/r/20240826204353.2228736-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240826204353.2228736-2-peterx@redhat.com
Signed-off-by: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Gavin Shan &lt;gshan@redhat.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch series "mm: Support huge pfnmaps", v2.

Overview
========

This series implements huge pfnmaps support for mm in general.  Huge
pfnmap allows e.g.  VM_PFNMAP vmas to map in either PMD or PUD levels,
similar to what we do with dax / thp / hugetlb so far to benefit from TLB
hits.  Now we extend that idea to PFN mappings, e.g.  PCI MMIO bars where
it can grow as large as 8GB or even bigger.

Currently, only x86_64 (1G+2M) and arm64 (2M) are supported.  The last
patch (from Alex Williamson) will be the first user of huge pfnmap, so as
to enable vfio-pci driver to fault in huge pfn mappings.

Implementation
==============

In reality, it's relatively simple to add such support comparing to many
other types of mappings, because of PFNMAP's specialties when there's no
vmemmap backing it, so that most of the kernel routines on huge mappings
should simply already fail for them, like GUPs or old-school follow_page()
(which is recently rewritten to be folio_walk* APIs by David).

One trick here is that we're still unmature on PUDs in generic paths here
and there, as DAX is so far the only user.  This patchset will add the 2nd
user of it.  Hugetlb can be a 3rd user if the hugetlb unification work can
go on smoothly, but to be discussed later.

The other trick is how to allow gup-fast working for such huge mappings
even if there's no direct sign of knowing whether it's a normal page or
MMIO mapping.  This series chose to keep the pte_special solution, so that
it reuses similar idea on setting a special bit to pfnmap PMDs/PUDs so
that gup-fast will be able to identify them and fail properly.

Along the way, we'll also notice that the major pgtable pfn walker, aka,
follow_pte(), will need to retire soon due to the fact that it only works
with ptes.  A new set of simple API is introduced (follow_pfnmap* API) to
be able to do whatever follow_pte() can already do, plus that it can also
process huge pfnmaps now.  Half of this series is about that and
converting all existing pfnmap walkers to use the new API properly. 
Hopefully the new API also looks better to avoid exposing e.g.  pgtable
lock details into the callers, so that it can be used in an even more
straightforward way.

Here, three more options will be introduced and involved in huge pfnmap:

  - ARCH_SUPPORTS_HUGE_PFNMAP

    Arch developers will need to select this option when huge pfnmap is
    supported in arch's Kconfig.  After this patchset applied, both x86_64
    and arm64 will start to enable it by default.

  - ARCH_SUPPORTS_PMD_PFNMAP / ARCH_SUPPORTS_PUD_PFNMAP

    These options are for driver developers to identify whether current
    arch / config supports huge pfnmaps, making decision on whether it can
    use the huge pfnmap APIs to inject them.  One can refer to the last
    vfio-pci patch from Alex on the use of them properly in a device
    driver.

So after the whole set applied, and if one would enable some dynamic debug
lines in vfio-pci core files, we should observe things like:

  vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x0: 0x100
  vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x200: 0x100
  vfio-pci 0000:00:06.0: vfio_pci_mmap_huge_fault(,order = 9) BAR 0 page offset 0x400: 0x100

In this specific case, it says that vfio-pci faults in PMDs properly for a
few BAR0 offsets.

Patch Layout
============

Patch 1:         Introduce the new options mentioned above for huge PFNMAPs
Patch 2:         A tiny cleanup
Patch 3-8:       Preparation patches for huge pfnmap (include introduce
                 special bit for pmd/pud)
Patch 9-16:      Introduce follow_pfnmap*() API, use it everywhere, and
                 then drop follow_pte() API
Patch 17:        Add huge pfnmap support for x86_64
Patch 18:        Add huge pfnmap support for arm64
Patch 19:        Add vfio-pci support for all kinds of huge pfnmaps (Alex)

TODO
====

More architectures / More page sizes
------------------------------------

Currently only x86_64 (2M+1G) and arm64 (2M) are supported.  There seems
to have plan to support arm64 1G later on top of this series [2].

Any arch will need to first support THP / THP_1G, then provide a special
bit in pmds/puds to support huge pfnmaps.

remap_pfn_range() support
-------------------------

Currently, remap_pfn_range() still only maps PTEs.  With the new option,
remap_pfn_range() can logically start to inject either PMDs or PUDs when
the alignment requirements match on the VAs.

When the support is there, it should be able to silently benefit all
drivers that is using remap_pfn_range() in its mmap() handler on better
TLB hit rate and overall faster MMIO accesses similar to processor on
hugepages.

More driver support
-------------------

VFIO is so far the only consumer for the huge pfnmaps after this series
applied.  Besides above remap_pfn_range() generic optimization, device
driver can also try to optimize its mmap() on a better VA alignment for
either PMD/PUD sizes.  This may, iiuc, normally require userspace changes,
as the driver doesn't normally decide the VA to map a bar.  But I don't
think I know all the drivers to know the full picture.

Credits all go to Alex on help testing the GPU/NIC use cases above.

[0] https://lore.kernel.org/r/73ad9540-3fb8-4154-9a4f-30a0a2b03d41@lucifer.local
[1] https://lore.kernel.org/r/20240807194812.819412-1-peterx@redhat.com
[2] https://lore.kernel.org/r/498e0731-81a4-4f75-95b4-a8ad0bcc7665@huawei.com


This patch (of 19):

This patch introduces the option to introduce special pte bit into
pmd/puds.  Archs can start to define pmd_special / pud_special when
supported by selecting the new option.  Per-arch support will be added
later.

Before that, create fallbacks for these helpers so that they are always
available.

Link: https://lkml.kernel.org/r/20240826204353.2228736-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240826204353.2228736-2-peterx@redhat.com
Signed-off-by: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Gavin Shan &lt;gshan@redhat.com&gt;
Cc: Gerald Schaefer &lt;gerald.schaefer@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux</title>
<updated>2024-09-16T11:33:06+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-16T11:33:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=26bb0d3f38a764b743a3ad5c8b6e5b5044d7ceb4'/>
<id>26bb0d3f38a764b743a3ad5c8b6e5b5044d7ceb4</id>
<content type='text'>
Pull block updates from Jens Axboe:

 - MD changes via Song:
      - md-bitmap refactoring (Yu Kuai)
      - raid5 performance optimization (Artur Paszkiewicz)
      - Other small fixes (Yu Kuai, Chen Ni)
      - Add a sysfs entry 'new_level' (Xiao Ni)
      - Improve information reported in /proc/mdstat (Mateusz Kusiak)

 - NVMe changes via Keith:
      - Asynchronous namespace scanning (Stuart)
      - TCP TLS updates (Hannes)
      - RDMA queue controller validation (Niklas)
      - Align field names to the spec (Anuj)
      - Metadata support validation (Puranjay)
      - A syntax cleanup (Shen)
      - Fix a Kconfig linking error (Arnd)
      - New queue-depth quirk (Keith)

 - Add missing unplug trace event (Keith)

 - blk-iocost fixes (Colin, Konstantin)

 - t10-pi modular removal and fixes (Alexey)

 - Fix for potential BLKSECDISCARD overflow (Alexey)

 - bio splitting cleanups and fixes (Christoph)

 - Deal with folios rather than rather than pages, speeding up how the
   block layer handles bigger IOs (Kundan)

 - Use spinlocks rather than bit spinlocks in zram (Sebastian, Mike)

 - Reduce zoned device overhead in ublk (Ming)

 - Add and use sendpages_ok() for drbd and nvme-tcp (Ofir)

 - Fix regression in partition error pointer checking (Riyan)

 - Add support for write zeroes and rotational status in nbd (Wouter)

 - Add Yu Kuai as new BFQ maintainer. The scheduler has been
   unmaintained for quite a while.

 - Various sets of fixes for BFQ (Yu Kuai)

 - Misc fixes and cleanups (Alvaro, Christophe, Li, Md Haris, Mikhail,
   Yang)

* tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux: (120 commits)
  nvme-pci: qdepth 1 quirk
  block: fix potential invalid pointer dereference in blk_add_partition
  blk_iocost: make read-only static array vrate_adj_pct const
  block: unpin user pages belonging to a folio at once
  mm: release number of pages of a folio
  block: introduce folio awareness and add a bigger size from folio
  block: Added folio-ized version of bio_add_hw_page()
  block, bfq: factor out a helper to split bfqq in bfq_init_rq()
  block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
  block, bfq: remove local variable 'split' in bfq_init_rq()
  block, bfq: remove bfq_log_bfqg()
  block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
  block, bfq: fix procress reference leakage for bfqq in merge chain
  block, bfq: fix uaf for accessing waker_bfqq after splitting
  blk-throttle: support prioritized processing of metadata
  blk-throttle: remove last_low_overflow_time
  drbd: Add NULL check for net_conf to prevent dereference in state validation
  nvme-tcp: fix link failure for TCP auth
  blk-mq: add missing unplug trace event
  mtip32xx: Remove redundant null pointer checks in mtip_hw_debugfs_init()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block updates from Jens Axboe:

 - MD changes via Song:
      - md-bitmap refactoring (Yu Kuai)
      - raid5 performance optimization (Artur Paszkiewicz)
      - Other small fixes (Yu Kuai, Chen Ni)
      - Add a sysfs entry 'new_level' (Xiao Ni)
      - Improve information reported in /proc/mdstat (Mateusz Kusiak)

 - NVMe changes via Keith:
      - Asynchronous namespace scanning (Stuart)
      - TCP TLS updates (Hannes)
      - RDMA queue controller validation (Niklas)
      - Align field names to the spec (Anuj)
      - Metadata support validation (Puranjay)
      - A syntax cleanup (Shen)
      - Fix a Kconfig linking error (Arnd)
      - New queue-depth quirk (Keith)

 - Add missing unplug trace event (Keith)

 - blk-iocost fixes (Colin, Konstantin)

 - t10-pi modular removal and fixes (Alexey)

 - Fix for potential BLKSECDISCARD overflow (Alexey)

 - bio splitting cleanups and fixes (Christoph)

 - Deal with folios rather than rather than pages, speeding up how the
   block layer handles bigger IOs (Kundan)

 - Use spinlocks rather than bit spinlocks in zram (Sebastian, Mike)

 - Reduce zoned device overhead in ublk (Ming)

 - Add and use sendpages_ok() for drbd and nvme-tcp (Ofir)

 - Fix regression in partition error pointer checking (Riyan)

 - Add support for write zeroes and rotational status in nbd (Wouter)

 - Add Yu Kuai as new BFQ maintainer. The scheduler has been
   unmaintained for quite a while.

 - Various sets of fixes for BFQ (Yu Kuai)

 - Misc fixes and cleanups (Alvaro, Christophe, Li, Md Haris, Mikhail,
   Yang)

* tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux: (120 commits)
  nvme-pci: qdepth 1 quirk
  block: fix potential invalid pointer dereference in blk_add_partition
  blk_iocost: make read-only static array vrate_adj_pct const
  block: unpin user pages belonging to a folio at once
  mm: release number of pages of a folio
  block: introduce folio awareness and add a bigger size from folio
  block: Added folio-ized version of bio_add_hw_page()
  block, bfq: factor out a helper to split bfqq in bfq_init_rq()
  block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
  block, bfq: remove local variable 'split' in bfq_init_rq()
  block, bfq: remove bfq_log_bfqg()
  block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
  block, bfq: fix procress reference leakage for bfqq in merge chain
  block, bfq: fix uaf for accessing waker_bfqq after splitting
  blk-throttle: support prioritized processing of metadata
  blk-throttle: remove last_low_overflow_time
  drbd: Add NULL check for net_conf to prevent dereference in state validation
  nvme-tcp: fix link failure for TCP auth
  blk-mq: add missing unplug trace event
  mtip32xx: Remove redundant null pointer checks in mtip_hw_debugfs_init()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux</title>
<updated>2024-09-16T04:55:07+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-16T04:55:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=114143a595895c03fbefccfd8346fc51fb4908ed'/>
<id>114143a595895c03fbefccfd8346fc51fb4908ed</id>
<content type='text'>
Pull arm64 updates from Will Deacon:
 "The highlights are support for Arm's "Permission Overlay Extension"
  using memory protection keys, support for running as a protected guest
  on Android as well as perf support for a bunch of new interconnect
  PMUs.

  Summary:

  ACPI:
   - Enable PMCG erratum workaround for HiSilicon HIP10 and 11
     platforms.
   - Ensure arm64-specific IORT header is covered by MAINTAINERS.

  CPU Errata:
   - Enable workaround for hardware access/dirty issue on Ampere-1A
     cores.

  Memory management:
   - Define PHYSMEM_END to fix a crash in the amdgpu driver.
   - Avoid tripping over invalid kernel mappings on the kexec() path.
   - Userspace support for the Permission Overlay Extension (POE) using
     protection keys.

  Perf and PMUs:
   - Add support for the "fixed instruction counter" extension in the
     CPU PMU architecture.
   - Extend and fix the event encodings for Apple's M1 CPU PMU.
   - Allow LSM hooks to decide on SPE permissions for physical
     profiling.
   - Add support for the CMN S3 and NI-700 PMUs.

  Confidential Computing:
   - Add support for booting an arm64 kernel as a protected guest under
     Android's "Protected KVM" (pKVM) hypervisor.

  Selftests:
   - Fix vector length issues in the SVE/SME sigreturn tests
   - Fix build warning in the ptrace tests.

  Timers:
   - Add support for PR_{G,S}ET_TSC so that 'rr' can deal with
     non-determinism arising from the architected counter.

  Miscellaneous:
   - Rework our IPI-based CPU stopping code to try NMIs if regular IPIs
     don't succeed.
   - Minor fixes and cleanups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits)
  perf: arm-ni: Fix an NULL vs IS_ERR() bug
  arm64: hibernate: Fix warning for cast from restricted gfp_t
  arm64: esr: Define ESR_ELx_EC_* constants as UL
  arm64: pkeys: remove redundant WARN
  perf: arm_pmuv3: Use BR_RETIRED for HW branch event if enabled
  MAINTAINERS: List Arm interconnect PMUs as supported
  perf: Add driver for Arm NI-700 interconnect PMU
  dt-bindings/perf: Add Arm NI-700 PMU
  perf/arm-cmn: Improve format attr printing
  perf/arm-cmn: Clean up unnecessary NUMA_NO_NODE check
  arm64/mm: use lm_alias() with addresses passed to memblock_free()
  mm: arm64: document why pte is not advanced in contpte_ptep_set_access_flags()
  arm64: Expose the end of the linear map in PHYSMEM_END
  arm64: trans_pgd: mark PTEs entries as valid to avoid dead kexec()
  arm64/mm: Delete __init region from memblock.reserved
  perf/arm-cmn: Support CMN S3
  dt-bindings: perf: arm-cmn: Add CMN S3
  perf/arm-cmn: Refactor DTC PMU register access
  perf/arm-cmn: Make cycle counts less surprising
  perf/arm-cmn: Improve build-time assertion
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull arm64 updates from Will Deacon:
 "The highlights are support for Arm's "Permission Overlay Extension"
  using memory protection keys, support for running as a protected guest
  on Android as well as perf support for a bunch of new interconnect
  PMUs.

  Summary:

  ACPI:
   - Enable PMCG erratum workaround for HiSilicon HIP10 and 11
     platforms.
   - Ensure arm64-specific IORT header is covered by MAINTAINERS.

  CPU Errata:
   - Enable workaround for hardware access/dirty issue on Ampere-1A
     cores.

  Memory management:
   - Define PHYSMEM_END to fix a crash in the amdgpu driver.
   - Avoid tripping over invalid kernel mappings on the kexec() path.
   - Userspace support for the Permission Overlay Extension (POE) using
     protection keys.

  Perf and PMUs:
   - Add support for the "fixed instruction counter" extension in the
     CPU PMU architecture.
   - Extend and fix the event encodings for Apple's M1 CPU PMU.
   - Allow LSM hooks to decide on SPE permissions for physical
     profiling.
   - Add support for the CMN S3 and NI-700 PMUs.

  Confidential Computing:
   - Add support for booting an arm64 kernel as a protected guest under
     Android's "Protected KVM" (pKVM) hypervisor.

  Selftests:
   - Fix vector length issues in the SVE/SME sigreturn tests
   - Fix build warning in the ptrace tests.

  Timers:
   - Add support for PR_{G,S}ET_TSC so that 'rr' can deal with
     non-determinism arising from the architected counter.

  Miscellaneous:
   - Rework our IPI-based CPU stopping code to try NMIs if regular IPIs
     don't succeed.
   - Minor fixes and cleanups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits)
  perf: arm-ni: Fix an NULL vs IS_ERR() bug
  arm64: hibernate: Fix warning for cast from restricted gfp_t
  arm64: esr: Define ESR_ELx_EC_* constants as UL
  arm64: pkeys: remove redundant WARN
  perf: arm_pmuv3: Use BR_RETIRED for HW branch event if enabled
  MAINTAINERS: List Arm interconnect PMUs as supported
  perf: Add driver for Arm NI-700 interconnect PMU
  dt-bindings/perf: Add Arm NI-700 PMU
  perf/arm-cmn: Improve format attr printing
  perf/arm-cmn: Clean up unnecessary NUMA_NO_NODE check
  arm64/mm: use lm_alias() with addresses passed to memblock_free()
  mm: arm64: document why pte is not advanced in contpte_ptep_set_access_flags()
  arm64: Expose the end of the linear map in PHYSMEM_END
  arm64: trans_pgd: mark PTEs entries as valid to avoid dead kexec()
  arm64/mm: Delete __init region from memblock.reserved
  perf/arm-cmn: Support CMN S3
  dt-bindings: perf: arm-cmn: Add CMN S3
  perf/arm-cmn: Refactor DTC PMU register access
  perf/arm-cmn: Make cycle counts less surprising
  perf/arm-cmn: Improve build-time assertion
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: Define VM_DROPPABLE for powerpc/32</title>
<updated>2024-09-13T15:28:36+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2024-09-02T19:17:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d175ee98fe545d2c56df22751314584cce228307'/>
<id>d175ee98fe545d2c56df22751314584cce228307</id>
<content type='text'>
Commit 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always
lazily freeable mappings") only adds VM_DROPPABLE for 64 bits
architectures.

In order to also use the getrandom vDSO implementation on powerpc/32,
use VM_ARCH_1 for VM_DROPPABLE on powerpc/32. This is possible because
VM_ARCH_1 is used for VM_SAO on powerpc and VM_SAO is only for
powerpc/64. It is used in combination with PROT_SAO in some parts of
code that are restricted to CONFIG_PPC64 through #ifdefs, it is
therefore possible to define VM_SAO for CONFIG_PPC64 only.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always
lazily freeable mappings") only adds VM_DROPPABLE for 64 bits
architectures.

In order to also use the getrandom vDSO implementation on powerpc/32,
use VM_ARCH_1 for VM_DROPPABLE on powerpc/32. This is possible because
VM_ARCH_1 is used for VM_SAO on powerpc and VM_SAO is only for
powerpc/64. It is used in combination with PROT_SAO in some parts of
code that are restricted to CONFIG_PPC64 through #ifdefs, it is
therefore possible to define VM_SAO for CONFIG_PPC64 only.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
