Commit Graph

1228 Commits

Author SHA1 Message Date
Linus Torvalds
aa486552a1 Merge tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock updates from Mike Rapoport:

 - new memblock_estimated_nr_free_pages() helper to replace
   totalram_pages() which is less accurate when
   CONFIG_DEFERRED_STRUCT_PAGE_INIT is set

 - fixes for memblock tests

* tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  s390/mm: get estimated free pages by memblock api
  kernel/fork.c: get estimated free pages by memblock api
  mm/memblock: introduce a new helper memblock_estimated_nr_free_pages()
  memblock test: fix implicit declaration of function 'strscpy'
  memblock test: fix implicit declaration of function 'isspace'
  memblock test: fix implicit declaration of function 'memparse'
  memblock test: add the definition of __setup()
  memblock test: fix implicit declaration of function 'virt_to_phys'
  tools/testing: abstract two init.h into common include directory
  memblock tests: include export.h in linkage.h as kernel dose
  memblock tests: include memory_hotplug.h in mmzone.h as kernel dose
2024-09-25 11:35:19 -07:00
Linus Torvalds
1ec6d09789 Merge tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:

 - Optimize ftrace and kprobes code patching and avoid stop machine for
   kprobes if sequential instruction fetching facility is available

 - Add hiperdispatch feature to dynamically adjust CPU capacity in
   vertical polarization to improve scheduling efficiency and overall
   performance. Also add infrastructure for handling warning track
   interrupts (WTI), allowing for graceful CPU preemption

 - Rework crypto code pkey module and split it into separate,
   independent modules for sysfs, PCKMO, CCA, and EP11, allowing modules
   to load only when the relevant hardware is available

 - Add hardware acceleration for HMAC modes and the full AES-XTS cipher,
   utilizing message-security assist extensions (MSA) 10 and 11. It
   introduces new shash implementations for HMAC-SHA224/256/384/512 and
   registers the hardware-accelerated AES-XTS cipher as the preferred
   option. Also add clear key token support

 - Add MSA 10 and 11 processor activity instrumentation counters to perf
   and update PAI Extension 1 NNPA counters

 - Cleanup cpu sampling facility code and rework debug/WARN_ON_ONCE
   statements

 - Add support for SHA3 performance enhancements introduced with MSA 12

 - Add support for the query authentication information feature of MSA
   13 and introduce the KDSA CPACF instruction. Provide query and query
   authentication information in sysfs, enabling tools like cpacfinfo to
   present this data in a human-readable form

 - Update kernel disassembler instructions

 - Always enable EXPOLINE_EXTERN if supported by the compiler to ensure
   kpatch compatibility

 - Add missing warning handling and relocated lowcore support to the
   early program check handler

 - Optimize ftrace_return_address() and avoid calling unwinder

 - Make modules use kernel ftrace trampolines

 - Strip relocs from the final vmlinux ELF file to make it roughly 2
   times smaller

 - Dump register contents and call trace for early crashes to the
   console

 - Generate ptdump address marker array dynamically

 - Fix rcu_sched stalls that might occur when adding or removing large
   amounts of pages at once to or from the CMM balloon

 - Fix deadlock caused by recursive lock of the AP bus scan mutex

 - Unify sync and async register save areas in entry code

 - Cleanup debug prints in crypto code

 - Various cleanup and sanitizing patches for the decompressor

 - Various small ftrace cleanups

* tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (84 commits)
  s390/crypto: Display Query and Query Authentication Information in sysfs
  s390/crypto: Add Support for Query Authentication Information
  s390/crypto: Rework RRE and RRF CPACF inline functions
  s390/crypto: Add KDSA CPACF Instruction
  s390/disassembler: Remove duplicate instruction format RSY_RDRU
  s390/boot: Move boot_printk() code to own file
  s390/boot: Use boot_printk() instead of sclp_early_printk()
  s390/boot: Rename decompressor_printk() to boot_printk()
  s390/boot: Compile all files with the same march flag
  s390: Use MARCH_HAS_*_FEATURES defines
  s390: Provide MARCH_HAS_*_FEATURES defines
  s390/facility: Disable compile time optimization for decompressor code
  s390/boot: Increase minimum architecture to z10
  s390/als: Remove obsolete comment
  s390/sha3: Fix SHA3 selftests failures
  s390/pkey: Add AES xts and HMAC clear key token support
  s390/cpacf: Add MSA 10 and 11 new PCKMO functions
  s390/mm: Add cond_resched() to cmm_alloc/free_pages()
  s390/pai_ext: Update PAI extension 1 counters
  s390/pai_crypto: Add support for MSA 10 and 11 pai counters
  ...
2024-09-21 09:02:54 -07:00
Linus Torvalds
617a814f14 Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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->pages[2] into xol_area->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
  ...
2024-09-21 07:29:05 -07:00
Mark Brown
25d4054cc9 mm: make arch_get_unmapped_area() take vm_flags by default
Patch series "mm: Care about shadow stack guard gap when getting an
unmapped area", v2.

As covered in the commit log for c44357c2e7 ("x86/mm: care about shadow
stack guard gap during placement") our current mmap() implementation does
not take care to ensure that a new mapping isn't placed with existing
mappings inside it's own guard gaps.  This is particularly important for
shadow stacks since if two shadow stacks end up getting placed adjacent to
each other then they can overflow into each other which weakens the
protection offered by the feature.

On x86 there is a custom arch_get_unmapped_area() which was updated by the
above commit to cover this case by specifying a start_gap for allocations
with VM_SHADOW_STACK.  Both arm64 and RISC-V have equivalent features and
use the generic implementation of arch_get_unmapped_area() so let's make
the equivalent change there so they also don't get shadow stack pages
placed without guard pages.  The arm64 and RISC-V shadow stack
implementations are currently on the list:

   https://lore.kernel.org/r/20240829-arm64-gcs-v12-0-42fec94743
   https://lore.kernel.org/lkml/20240403234054.2020347-1-debug@rivosinc.com/

Given the addition of the use of vm_flags in the generic implementation we
also simplify the set of possibilities that have to be dealt with in the
core code by making arch_get_unmapped_area() take vm_flags as standard. 
This is a bit invasive since the prototype change touches quite a few
architectures but since the parameter is ignored the change is
straightforward, the simplification for the generic code seems worth it.


This patch (of 3):

When we introduced arch_get_unmapped_area_vmflags() in 961148704a ("mm:
introduce arch_get_unmapped_area_vmflags()") we did so as part of properly
supporting guard pages for shadow stacks on x86_64, which uses a custom
arch_get_unmapped_area().  Equivalent features are also present on both
arm64 and RISC-V, both of which use the generic implementation of
arch_get_unmapped_area() and will require equivalent modification there. 
Rather than continue to deal with having two versions of the functions
let's bite the bullet and have all implementations of
arch_get_unmapped_area() take vm_flags as a parameter.

The new parameter is currently ignored by all implementations other than
x86.  The only caller that doesn't have a vm_flags available is
mm_get_unmapped_area(), as for the x86 implementation and the wrapper used
on other architectures this is modified to supply no flags.

No functional changes.

Link: https://lkml.kernel.org/r/20240904-mm-generic-shadow-stack-guard-v2-0-a46b8b6dc0ed@kernel.org
Link: https://lkml.kernel.org/r/20240904-mm-generic-shadow-stack-guard-v2-1-a46b8b6dc0ed@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Helge Deller <deller@gmx.de>	[parisc]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:13 -07:00
Gerald Schaefer
131b8db785 s390/mm: Add cond_resched() to cmm_alloc/free_pages()
Adding/removing large amount of pages at once to/from the CMM balloon
can result in rcu_sched stalls or workqueue lockups, because of busy
looping w/o cond_resched().

Prevent this by adding a cond_resched(). cmm_free_pages() holds a
spin_lock while looping, so it cannot be added directly to the existing
loop. Instead, introduce a wrapper function that operates on maximum 256
pages at once, and add it there.

Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-05 15:17:23 +02:00
David Hildenbrand
0b31a3cef4 s390/mm/fault: convert do_secure_storage_access() from follow_page() to folio_walk
Let's get rid of another follow_page() user and perform the conversion
under PTL: Note that this is also what follow_page_pte() ends up doing.

Unfortunately we cannot currently optimize out the additional reference,
because arch_make_folio_accessible() must be called with a raised refcount
to protect against concurrent conversion to secure.  We can just move the
arch_make_folio_accessible() under the PTL, like follow_page_pte() would.

We'll effectively drop the "writable" check implied by FOLL_WRITE:
follow_page_pte() would also not check that when calling
arch_make_folio_accessible(), so there is no good reason for doing that
here.

We'll lose the secretmem check from follow_page() as well, about which we
shouldn't really care.

Link: https://lkml.kernel.org/r/20240802155524.517137-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:01 -07:00
Catalin Marinas
ba0fb44aed dma-mapping: replace zone_dma_bits by zone_dma_limit
The hardware DMA limit might not be power of 2. When RAM range starts
above 0, say 4GB, DMA limit of 30 bits should end at 5GB.  A single high
bit can not encode this limit.

Use a plain  address for the DMA zone limit instead.

Since the DMA zone can now potentially span beyond 4GB physical limit of
DMA32, make sure to use DMA zone for GFP_DMA32 allocations in that case.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-22 06:18:00 +02:00
Wei Yang
cb088e38aa s390/mm: get estimated free pages by memblock api
Instead of getting estimated free pages from memblock directly, we have
introduced an API, memblock_estimated_nr_free_pages(), which is more
friendly for users.

Just replace it with new API, no functional change.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Mike Rapoport <rppt@kernel.org>
CC: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240808001415.6298-3-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2024-08-11 19:19:07 +03:00
Heiko Carstens
d0e7915d2a s390/mm/ptdump: Generate address marker array dynamically
Generate the address marker array dynamically instead of modifying a large
static array at kernel startup. Each marker is added twice to the array:
with and without a "start" indicator. This way the code and logic stays
similar to other architectures.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-07 20:52:53 +02:00
Heiko Carstens
33bd8d153c s390: Keep inittext section writable
There is no added security by making the inittext section non-writable,
however it does split part of the kernel mapping into 4K mappings
instead of 1M mappings:

---[ Kernel Image Start ]---
0x000003ffe0000000-0x000003ffe0e00000        14M PMD RO X
0x000003ffe0e00000-0x000003ffe0ec7000       796K PTE RO X
0x000003ffe0ec7000-0x000003ffe0f00000       228K PTE RO NX
0x000003ffe0f00000-0x000003ffe1300000         4M PMD RO NX
0x000003ffe1300000-0x000003ffe1353000       332K PTE RO NX
0x000003ffe1353000-0x000003ffe1400000       692K PTE RW NX
0x000003ffe1400000-0x000003ffe1500000         1M PMD RW NX
0x000003ffe1500000-0x000003ffe1700000         2M PTE RW NX <---
0x000003ffe1700000-0x000003ffe1800000         1M PMD RW NX
0x000003ffe1800000-0x000003ffe187e000       504K PTE RW NX
---[ Kernel Image End ]---

Keep the inittext writable and enable instruction execution protection
(aka noexec) later to prevent this. This also allows to use the
generic free_initmem() implementation.

---[ Kernel Image Start ]---
0x000003ffe0000000-0x000003ffe0e00000        14M PMD RO X
0x000003ffe0e00000-0x000003ffe0ec7000       796K PTE RO X
0x000003ffe0ec7000-0x000003ffe0f00000       228K PTE RO NX
0x000003ffe0f00000-0x000003ffe1300000         4M PMD RO NX
0x000003ffe1300000-0x000003ffe1353000       332K PTE RO NX
0x000003ffe1353000-0x000003ffe1400000       692K PTE RW NX
0x000003ffe1400000-0x000003ffe1800000         4M PMD RW NX <---
0x000003ffe1800000-0x000003ffe187e000       504K PTE RW NX
---[ Kernel Image End ]---

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-31 16:30:20 +02:00
Heiko Carstens
1e72ba5566 s390/mm: Get rid of RELOC_HIDE()
Since __va(0) does not translate to NULL anymore remove RELOC_HIDE()
which was only added to get rid of a compile warning with clang W=1:

    arch/s390/mm/vmem.c:666:36: warning: performing pointer arithmetic on
     a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
      666 |                 __set_memory_4k(__va(0), __va(0) + ident_map_size);
          |                                          ~~~~~~~ ^

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-31 16:30:20 +02:00
Heiko Carstens
7e12284c52 s390/mm/ptdump: Improve sorting of markers
Use the sort() from lib/sort.c to sort markers instead of the private
implementation. The current implementation does not sort markers
properly if they have to be moved downwards:

---[ Real Memory Copy Area Start ]---
0x0000035b903ff000-0x0000035b90400000         4K PTE I
---[ vmalloc Area Start ]---
---[ Real Memory Copy Area End ]---

Add a new member to each marker which indicates if a marker is start
of an area. If addresses of areas are equal consider an address which
defines the start of an area higher than the address which defines the
end of an area. In result the output is sorted as intended:

---[ Real Memory Copy Area Start ]---
0x0000019cedcff000-0x0000019cedd00000         4K PTE I
---[ Real Memory Copy Area End ]---
---[ vmalloc Area Start ]---

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-31 16:30:20 +02:00
Heiko Carstens
7e4d4cfed6 s390/mm/ptdump: Add support for relocated lowcore mapping
The page table dumper contains a hard coded assumption that the first
mapped area starts at address zero. With a relocated lowcore this is
not true anymore. Subsequently the first entry (lowcore) is printed as
if it would contain everything from address zero until the end of the
location of the lowcore area.

Fix this by adding a single "Kernel Virtual Address Space" entry,
which always starts at address zero. It ends when the lowcore area
starts which is either address zero, or its relocated address.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-31 16:30:20 +02:00
Heiko Carstens
373953444c s390/mm/ptdump: Fix handling of identity mapping area
Since virtual and real addresses are not the same anymore the
assumption that the kernel image is contained within the identity
mapping is also not true anymore.

Fix this by adding two explicit areas and at the correct locations: one
for the 8kb lowcore area, and one for the identity mapping.

Fixes: c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-31 16:30:20 +02:00
Linus Torvalds
65ad409e63 Merge tag 's390-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Vasily Gorbik:

 - Fix KMSAN build breakage caused by the conflict between s390 and
   mm-stable trees

 - Add KMSAN page markers for ptdump

 - Add runtime constant support

 - Fix __pa/__va for modules under non-GPL licenses by exporting
   necessary vm_layout struct with EXPORT_SYMBOL to prevent linkage
   problems

 - Fix an endless loop in the CF_DIAG event stop in the CPU Measurement
   Counter Facility code when the counter set size is zero

 - Remove the PROTECTED_VIRTUALIZATION_GUEST config option and enable
   its functionality by default

 - Support allocation of multiple MSI interrupts per device and improve
   logging of architecture-specific limitations

 - Add support for lowcore relocation as a debugging feature to catch
   all null ptr dereferences in the kernel address space, improving
   detection beyond the current implementation's limited write access
   protection

 - Clean up and rework CPU alternatives to allow for callbacks and early
   patching for the lowcore relocation

* tag 's390-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
  s390: Remove protvirt and kvm config guards for uv code
  s390/boot: Add cmdline option to relocate lowcore
  s390/kdump: Make kdump ready for lowcore relocation
  s390/entry: Make system_call() ready for lowcore relocation
  s390/entry: Make ret_from_fork() ready for lowcore relocation
  s390/entry: Make __switch_to() ready for lowcore relocation
  s390/entry: Make restart_int_handler() ready for lowcore relocation
  s390/entry: Make mchk_int_handler() ready for lowcore relocation
  s390/entry: Make int handlers ready for lowcore relocation
  s390/entry: Make pgm_check_handler() ready for lowcore relocation
  s390/entry: Add base register to CHECK_VMAP_STACK/CHECK_STACK macro
  s390/entry: Add base register to SIEEXIT macro
  s390/entry: Add base register to MBEAR macro
  s390/entry: Make __sie64a() ready for lowcore relocation
  s390/head64: Make startup code ready for lowcore relocation
  s390: Add infrastructure to patch lowcore accesses
  s390/atomic_ops: Disable flag outputs constraint for GCC versions below 14.2.0
  s390/entry: Move SIE indicator flag to thread info
  s390/nmi: Simplify ptregs setup
  s390/alternatives: Remove alternative facility list
  ...
2024-07-26 10:47:53 -07:00
Joel Granados
78eb4ea25c sysctl: treewide: constify the ctl_table argument of proc_handlers
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
  virtual patch

  @r1@
  identifier ctl, write, buffer, lenp, ppos;
  identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

  @r2@
  identifier func, ctl, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos)
  { ... }

  @r3@
  identifier func;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int , void *, size_t *, loff_t *);

  @r4@
  identifier func, ctl;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int , void *, size_t *, loff_t *);

  @r5@
  identifier func, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
  conventions. The xfs_stats_clear_proc_handler,
  xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
  adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
  This is called from a proc_handler itself and is calling back into
  another proc_handler, making it necessary to change it as part of the
  proc_handler migration.

Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-07-24 20:59:29 +02:00
Heiko Carstens
030f7951c5 s390/uaccess: Make s390_kernel_write() usable for decompressor
To avoid lots of ifdefs in C code make s390_kernel_write() usable for
the decompressor: simply use memcpy() for this case since there is no
write protection enabled that early.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23 16:02:31 +02:00
Ilya Leoshkevich
19af288706 s390/ptdump: Add KMSAN page markers
Add KMSAN vmalloc metadata areas to
/sys/kernel/debug/kernel_page_tables. Example output:

    0x000003a95fff9000-0x000003a960000000        28K PTE I
    ---[ vmalloc Area End ]---
    ---[ Kmsan vmalloc Shadow Start ]---
    0x000003a960000000-0x000003a960010000        64K PTE RW NX
    [...]
    0x000003d3dfff9000-0x000003d3e0000000        28K PTE I
    ---[ Kmsan vmalloc Shadow End ]---
    ---[ Kmsan vmalloc Origins Start ]---
    0x000003d3e0000000-0x000003d3e0010000        64K PTE RW NX
    [...]
    0x000003fe5fff9000-0x000003fe60000000        28K PTE I
    ---[ Kmsan vmalloc Origins End ]---
    ---[ Kmsan Modules Shadow Start ]---
    0x000003fe60000000-0x000003fe60001000         4K PTE RW NX
    [...]
    0x000003fe60100000-0x000003fee0000000      2047M PMD I
    ---[ Kmsan Modules Shadow End ]---
    ---[ Kmsan Modules Origins Start ]---
    0x000003fee0000000-0x000003fee0001000         4K PTE RW NX
    [...]
    0x000003fee0100000-0x000003ff60000000      2047M PMD I
    ---[ Kmsan Modules Origins End ]---
    ---[ Modules Area Start ]---
    0x000003ff60000000-0x000003ff60001000         4K PTE RO X

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20240723124441.120044-3-iii@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23 16:01:51 +02:00
Linus Torvalds
fbc90c042c Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Linus Torvalds
1c7d0c3af5 Merge tag 's390-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:

 - Remove restrictions on PAI NNPA and crypto counters, enabling
   concurrent per-task and system-wide sampling and counting events

 - Switch to GENERIC_CPU_DEVICES by setting up the CPU present mask in
   the architecture code and letting the generic code handle CPU
   bring-up

 - Add support for the diag204 busy indication facility to prevent
   undesirable blocking during hypervisor logical CPU utilization
   queries. Implement results caching

 - Improve the handling of Store Data SCLP events by suppressing
   unnecessary warning, preventing buffer release in I/O during
   failures, and adding timeout handling for Store Data requests to
   address potential firmware issues

 - Provide optimized __arch_hweight*() implementations

 - Remove the unnecessary CPU KOBJ_CHANGE uevents generated during
   topology updates, as they are unused and also not present on other
   architectures

 - Cleanup atomic_ops, optimize __atomic_set() for small values and
   __atomic_cmpxchg_bool() for compilers supporting flag output
   constraint

 - Couple of cleanups for KVM:
     - Move and improve KVM struct definitions for DAT tables from
       gaccess.c to a new header
     - Pass the asce as parameter to sie64a()

 - Make the crdte() and cspg() page table handling wrappers return a
   boolean to indicate success, like the other existing "compare and
   swap" wrappers

 - Add documentation for HWCAP flags

 - Switch to obtaining total RAM pages from memblock instead of
   totalram_pages() during mm init, to ensure correct calculation of
   zero page size, when defer_init is enabled

 - Refactor lowcore access and switch to using the get_lowcore()
   function instead of the S390_lowcore macro

 - Cleanups for PG_arch_1 and folio handling in UV and hugetlb code

 - Add missing MODULE_DESCRIPTION() macros

 - Fix VM_FAULT_HWPOISON handling in do_exception()

* tag 's390-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
  s390/mm: Fix VM_FAULT_HWPOISON handling in do_exception()
  s390/kvm: Move bitfields for dat tables
  s390/entry: Pass the asce as parameter to sie64a()
  s390/sthyi: Use cached data when diag is busy
  s390/sthyi: Move diag operations
  s390/hypfs_diag: Diag204 busy loop
  s390/diag: Add busy-indication-facility requirements
  s390/diag: Diag204 add busy return errno
  s390/diag: Return errno's from diag204
  s390/sclp: Diag204 busy indication facility detection
  s390/atomic_ops: Make use of flag output constraint
  s390/atomic_ops: Improve __atomic_set() for small values
  s390/atomic_ops: Use symbolic names
  s390/smp: Switch to GENERIC_CPU_DEVICES
  s390/hwcaps: Add documentation for HWCAP flags
  s390/pgtable: Make crdte() and cspg() return a value
  s390/topology: Remove CPU KOBJ_CHANGE uevents
  s390/sclp: Add timeout to Store Data requests
  s390/sclp: Prevent release of buffer in I/O
  s390/sclp: Suppress unnecessary Store Data warning
  ...
2024-07-18 15:41:45 -07:00
Gerald Schaefer
df39038cd8 s390/mm: Fix VM_FAULT_HWPOISON handling in do_exception()
There is no support for HWPOISON, MEMORY_FAILURE, or ARCH_HAS_COPY_MC on
s390. Therefore we do not expect to see VM_FAULT_HWPOISON in
do_exception().

However, since commit af19487f00 ("mm: make PTE_MARKER_SWAPIN_ERROR more
general"), it is possible to see VM_FAULT_HWPOISON in combination with
PTE_MARKER_POISONED, even on architectures that do not support HWPOISON
otherwise. In this case, we will end up on the BUG() in do_exception().

Fix this by treating VM_FAULT_HWPOISON the same as VM_FAULT_SIGBUS, similar
to x86 when MEMORY_FAILURE is not configured. Also print unexpected fault
flags, for easier debugging.

Note that VM_FAULT_HWPOISON_LARGE is not expected, because s390 cannot
support swap entries on other levels than PTE level.

Cc: stable@vger.kernel.org # 6.6+
Fixes: af19487f00 ("mm: make PTE_MARKER_SWAPIN_ERROR more general")
Reported-by: Yunseong Kim <yskelg@gmail.com>
Tested-by: Yunseong Kim <yskelg@gmail.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Message-ID: <20240715180416.3632453-1-gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-17 14:30:30 +02:00
Christophe Leroy
e6c0c03245 mm: provide mm_struct and address to huge_ptep_get()
On powerpc 8xx huge_ptep_get() will need to know whether the given ptep is
a PTE entry or a PMD entry.  This cannot be known with the PMD entry
itself because there is no easy way to know it from the content of the
entry.

So huge_ptep_get() will need to know either the size of the page or get
the pmd.

In order to be consistent with huge_ptep_get_and_clear(), give mm and
address to huge_ptep_get().

Link: https://lkml.kernel.org/r/cc00c70dd384298796a4e1b25d6c4eb306d3af85.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:15 -07:00
Heiko Carstens
b5efb63acf s390/mm: Add NULL pointer check to crst_table_free() base_crst_free()
crst_table_free() used to work with NULL pointers before the conversion
to ptdescs.  Since crst_table_free() can be called with a NULL pointer
(error handling in crst_table_upgrade() add an explicit check.

Also add the same check to base_crst_free() for consistency reasons.

In real life this should not happen, since order two GFP_KERNEL
allocations will not fail, unless FAIL_PAGE_ALLOC is enabled and used.

Reported-by: Yunseong Kim <yskelg@gmail.com>
Fixes: 6326c26c15 ("s390: convert various pgalloc functions to use ptdescs")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-09 07:38:39 -07:00
Jeff Johnson
7a6d19c3c7 s390/mm: Add missing MODULE_DESCRIPTION() macro
With ARCH=s390, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/s390/mm/cmm.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240615-md-s390-arch-s390-mm-v1-1-a360eed8c7c3@quicinc.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-06-28 14:52:31 +02:00
Wei Yang
37db17c100 s390/mm: Get total ram pages from memblock
On s390, zero page's size relies on total ram pages.

Since we plan to move the accounting into __free_pages_core(),
totalram_pages may not represent the total usable pages on system
at this point when defer_init is enabled.

We can get the total usable pages from memblock directly. The size maybe
not accurate due to the alignment, but enough for the calculation.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Mike Rapoport (IBM) <rppt@kernel.org>
CC: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240616013537.20338-1-richard.weiyang@gmail.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-06-24 11:12:39 +02:00
Sven Schnelle
208da1d5fc s390: Replace S390_lowcore by get_lowcore()
Replace all S390_lowcore usages in arch/s390/ by get_lowcore().

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-06-18 17:01:33 +02:00
David Hildenbrand
1433b36e3a s390/hugetlb: Convert PG_arch_1 code to work on folio->flags
Let's make it clearer that we are always working on folio flags and
never page flags of tail pages by converting remaining PG_arch_1 users
that modify page->flags to modify folio->flags instead.

No functional change intended, because we would always have worked with
the head page (where page->flags corresponds to folio->flags) and never
with tail pages.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240508182955.358628-11-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-06-05 17:17:26 +02:00
David Hildenbrand
99b3f8f76f s390/uv: Implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
Let's also implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE, so we can convert
arch_make_page_accessible() to be a simple wrapper around
arch_make_folio_accessible(). Unfortunately, we cannot do that in the
header.

There are only two arch_make_page_accessible() calls remaining in gup.c.
We can now drop HAVE_ARCH_MAKE_PAGE_ACCESSIBLE completely form core-MM.
We'll handle that separately, once the s390x part landed.

Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240508182955.358628-10-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-06-05 17:17:25 +02:00
David Hildenbrand
7063150650 s390/uv: Convert uv_destroy_owned_page() to uv_destroy_(folio|pte)()
Let's have the following variants for destroying pages:

(1) uv_destroy(): Like uv_pin_shared() and uv_convert_from_secure(),
"low level" helper that operates on paddr and doesn't mess with folios.

(2) uv_destroy_folio(): Consumes a folio to which we hold a reference.

(3) uv_destroy_pte(): Consumes a PTE that holds a reference through the
mapping.

Unfortunately we need uv_destroy_pte(), because pfn_folio() and
friends are not available in pgtable.h.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240508182955.358628-8-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-06-05 17:17:25 +02:00
Linus Torvalds
61307b7be4 Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
2024-05-19 09:21:03 -07:00
Mike Rapoport (IBM)
0cc2dc4902 arch: make execmem setup available regardless of CONFIG_MODULES
execmem does not depend on modules, on the contrary modules use
execmem.

To make execmem available when CONFIG_MODULES=n, for instance for
kprobes, split execmem_params initialization out from
arch/*/kernel/module.c and compile it when CONFIG_EXECMEM=y

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14 00:31:44 -07:00
Linus Torvalds
d65e1a0f30 Merge tag 's390-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev:

 - Store AP Query Configuration Information in a static buffer

 - Rework the AP initialization and add missing cleanups to the error
   path

 - Swap IRQ and AP bus/device registration to avoid race conditions

 - Export prot_virt_guest symbol

 - Introduce AP configuration changes notifier interface to facilitate
   modularization of the AP bus

 - Add CONFIG_AP kernel configuration option to allow modularization of
   the AP bus

 - Rework CONFIG_ZCRYPT_DEBUG kernel configuration option description
   and dependency and rename it to CONFIG_AP_DEBUG

 - Convert sprintf() and snprintf() to sysfs_emit() in CIO code

 - Adjust indentation of RELOCS command build step

 - Make crypto performance counters upward compatible

 - Convert make_page_secure() and gmap_make_secure() to use folio

 - Rework channel-utilization-block (CUB) handling in preparation of
   introducing additional CUBs

 - Use attribute groups to simplify registration, removal and extension
   of measurement-related channel-path sysfs attributes

 - Add a per-channel-path binary "ext_measurement" sysfs attribute that
   provides access to extended channel-path measurement data

 - Export measurement data for all channel-measurement-groups (CMG), not
   only for a specific ones. This enables support of new CMG data
   formats in userspace without the need for kernel changes

 - Add a per-channel-path sysfs attribute "speed_bps" that provides the
   operating speed in bits per second or 0 if the operating speed is not
   available

 - The CIO tracepoint subchannel-type field "st" is incorrectly set to
   the value of subchannel-enabled SCHIB "ena" field. Fix that

 - Do not forcefully limit vmemmap starting address to MAX_PHYSMEM_BITS

 - Consider the maximum physical address available to a DCSS segment
   (512GB) when memory layout is set up

 - Simplify the virtual memory layout setup by reducing the size of
   identity mapping vs vmemmap overlap

 - Swap vmalloc and Lowcore/Real Memory Copy areas in virtual memory.
   This will allow to place the kernel image next to kernel modules

 - Move everyting KASLR related from <asm/setup.h> to <asm/page.h>

 - Put virtual memory layout information into a structure to improve
   code generation

 - Currently __kaslr_offset is the kernel offset in both physical and
   virtual memory spaces. Uncouple these offsets to allow uncoupling of
   the addresses spaces

 - Currently the identity mapping base address is implicit and is always
   set to zero. Make it explicit by putting into __identity_base
   persistent boot variable and use it in proper context

 - Introduce .amode31 section start and end macros AMODE31_START and
   AMODE31_END

 - Introduce OS_INFO entries that do not reference any data in memory,
   but rather provide only values

 - Store virtual memory layout in OS_INFO. It is read out by
   makedumpfile, crash and other tools

 - Store virtual memory layout in VMCORE_INFO. It is read out by crash
   and other tools when /proc/kcore device is used

 - Create additional PT_LOAD ELF program header that covers kernel image
   only, so that vmcore tools could locate kernel text and data when
   virtual and physical memory spaces are uncoupled

 - Uncouple physical and virtual address spaces

 - Map kernel at fixed location when KASLR mode is disabled. The
   location is defined by CONFIG_KERNEL_IMAGE_BASE kernel configuration
   value.

 - Rework deployment of kernel image for both compressed and
   uncompressed variants as defined by CONFIG_KERNEL_UNCOMPRESSED kernel
   configuration value

 - Move .vmlinux.relocs section in front of the compressed kernel. The
   interim section rescue step is avoided as result

 - Correct modules thunk offset calculation when branch target is more
   than 2GB away

 - Kernel modules contain their own set of expoline thunks. Now that the
   kernel modules area is less than 4GB away from kernel expoline
   thunks, make modules use kernel expolines. Also make EXPOLINE_EXTERN
   the default if the compiler supports it

 - userfaultfd can insert shared zeropages into processes running VMs,
   but that is not allowed for s390. Fallback to allocating a fresh
   zeroed anonymous folio and insert that instead

 - Re-enable shared zeropages for non-PV and non-skeys KVM guests

 - Rename hex2bitmap() to ap_hex2bitmap() and export it for external use

 - Add ap_config sysfs attribute to provide the means for setting or
   displaying adapters, domains and control domains assigned to a
   vfio-ap mediated device in a single operation

 - Make vfio_ap_mdev_link_queue() ignore duplicate link requests

 - Add write support to ap_config sysfs attribute to allow atomic update
   a vfio-ap mediated device state

 - Document ap_config sysfs attribute

 - Function os_info_old_init() is expected to be called only from a
   regular kdump kernel. Enable it to be called from a stand-alone dump
   kernel

 - Address gcc -Warray-bounds warning and fix array size in struct
   os_info

 - s390 does not support SMBIOS, so drop unneeded CONFIG_DMI checks

 - Use unwinder instead of __builtin_return_address() with ftrace to
   prevent returning of undefined values

 - Sections .hash and .gnu.hash are only created when CONFIG_PIE_BUILD
   kernel is enabled. Drop these for the case CONFIG_PIE_BUILD is
   disabled

 - Compile kernel with -fPIC and link with -no-pie to allow kpatch
   feature always succeed and drop the whole CONFIG_PIE_BUILD
   option-enabled code

 - Add missing virt_to_phys() converter for VSIE facility and crypto
   control blocks

* tag 's390-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
  Revert "s390: Relocate vmlinux ELF data to virtual address space"
  KVM: s390: vsie: Use virt_to_phys for crypto control block
  s390: Relocate vmlinux ELF data to virtual address space
  s390: Compile kernel with -fPIC and link with -no-pie
  s390: vmlinux.lds.S: Drop .hash and .gnu.hash for !CONFIG_PIE_BUILD
  s390/ftrace: Use unwinder instead of __builtin_return_address()
  s390/pci: Drop unneeded reference to CONFIG_DMI
  s390/os_info: Fix array size in struct os_info
  s390/os_info: Initialize old os_info in standalone dump kernel
  docs: Update s390 vfio-ap doc for ap_config sysfs attribute
  s390/vfio-ap: Add write support to sysfs attr ap_config
  s390/vfio-ap: Ignore duplicate link requests in vfio_ap_mdev_link_queue
  s390/vfio-ap: Add sysfs attr, ap_config, to export mdev state
  s390/ap: Externalize AP bus specific bitmap reading function
  s390/mm: Re-enable the shared zeropage for !PV and !skeys KVM guests
  mm/userfaultfd: Do not place zeropages when zeropages are disallowed
  s390/expoline: Make modules use kernel expolines
  s390/nospec: Correct modules thunk offset calculation
  s390/boot: Do not rescue .vmlinux.relocs section
  s390/boot: Rework deployment of the kernel image
  ...
2024-05-13 08:33:52 -07:00
Alexander Gordeev
22a49f6d30 Merge branch 'shared-zeropage' into features
David Hildenbrand says:

===================
This series fixes one issue with uffd + shared zeropages on s390x and
fixes that "ordinary" KVM guests can make use of shared zeropages again.

userfaultfd could currently end up mapping shared zeropages into processes
that forbid shared zeropages. This only apples to s390x, relevant for
handling PV guests and guests that use storage kets correctly. Fix it
by placing a zeroed folio instead of the shared zeropage during
UFFDIO_ZEROPAGE instead.

I stumbled over this issue while looking into a customer scenario that
is using:

(1) Memory ballooning for dynamic resizing. Start a VM with, say, 100 GiB
    and inflate the balloon during boot to 60 GiB. The VM has ~40 GiB
    available and additional memory can be "fake hotplugged" to the VM
    later on demand by deflating the balloon. Actual memory overcommit is
    not desired, so physical memory would only be moved between VMs.

(2) Live migration of VMs between sites to evacuate servers in case of
    emergency.

Without the shared zeropage, during (2), the VM would suddenly consume
100 GiB on the migration source and destination. On the migration source,
where we don't excpect memory overcommit, we could easilt end up crashing
the VM during migration.

Independent of that, memory handed back to the hypervisor using "free page
reporting" would end up consuming actual memory after the migration on the
destination, not getting freed up until reused+freed again.

While there might be ways to optimize parts of this in QEMU, we really
should just support the shared zeropage again for ordinary VMs.

We only expect legcy guests to make use of storage keys, so let's handle
zeropages again when enabling storage keys or when enabling PV. To not
break userfaultfd like we did in the past, don't zap the shared zeropages,
but instead trigger unsharing faults, just like we do for unsharing
KSM pages in break_ksm().

Unsharing faults will simply replace the shared zeropage by a zeroed
anonymous folio. We can already trigger the same fault path using GUP,
when trying to long-term pin a shared zeropage, but also when unmerging
a KSM-placed zeropages, so this is nothing new.

Patch #1 tested on 86-64 by forcing mm_forbids_zeropage() to be 1, and
running the uffd selftests.

Patch #2 tested on s390x: the live migration scenario now works as
expected, and kvm-unit-tests that trigger usage of skeys work well, whereby
I can see detection and unsharing of shared zeropages.

Further (as broken in v2), I tested that the shared zeropage is no
longer populated after skeys are used -- that mm_forbids_zeropage() works
as expected:
  ./s390x-run s390x/skey.elf \
   -no-shutdown \
   -chardev socket,id=monitor,path=/var/tmp/mon,server,nowait \
   -mon chardev=monitor,mode=readline

  Then, in another shell:

  # cat /proc/`pgrep qemu`/smaps_rollup | grep Rss
  Rss:               31484 kB
  #  echo "dump-guest-memory tmp" | sudo nc -U /var/tmp/mon
  ...
  # cat /proc/`pgrep qemu`/smaps_rollup | grep Rss
  Rss:              160452 kB

  -> Reading guest memory does not populate the shared zeropage

  Doing the same with selftest.elf (no skeys)

  # cat /proc/`pgrep qemu`/smaps_rollup | grep Rss
  Rss:               30900 kB
  #  echo "dump-guest-memory tmp" | sudo nc -U /var/tmp/mon
  ...
  # cat /proc/`pgrep qemu`/smaps_rollup | grep Rsstmp/mon
  Rss:               30924 kB

  -> Reading guest memory does populate the shared zeropage
===================

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-05-02 22:02:25 +02:00
Kefeng Wang
82b7a61839 s390: mm: accelerate pagefault when badaccess
The vm_flags of vma already checked under per-VMA lock, if it is a bad
access, directly handle error, no need to retry with mmap_lock again. 
Since the page faut is handled under per-VMA lock, count it as a vma lock
event with VMA_LOCK_SUCCESS.

Link: https://lkml.kernel.org/r/20240403083805.1818160-7-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:39 -07:00
Rick Edgecombe
b80fa3cbb7 treewide: use initializer for struct vm_unmapped_area_info
Future changes will need to add a new member to struct
vm_unmapped_area_info.  This would cause trouble for any call site that
doesn't initialize the struct.  Currently every caller sets each member
manually, so if new ones are added they will be uninitialized and the core
code parsing the struct will see garbage in the new member.

It could be possible to initialize the new member manually to 0 at each
call site.  This and a couple other options were discussed.  Having some
struct vm_unmapped_area_info instances not zero initialized will put those
sites at risk of feeding garbage into vm_unmapped_area(), if the
convention is to zero initialize the struct and any new field addition
missed a call site that initializes each field manually.  So it is useful
to do things similar across the kernel.

The consensus (see links) was that in general the best way to accomplish
taking into account both code cleanliness and minimizing the chance of
introducing bugs, was to do C99 static initialization.  As in: struct
vm_unmapped_area_info info = {};

With this method of initialization, the whole struct will be zero
initialized, and any statements setting fields to zero will be unneeded. 
The change should not leave cleanup at the call sides.

While iterating though the possible solutions a few archs kindly acked
other variations that still zero initialized the struct.  These sites have
been modified in previous changes using the pattern acked by the
respective arch.

So to be reduce the chance of bugs via uninitialized fields, perform a
tree wide change using the consensus for the best general way to do this
change.  Use C99 static initializing to zero the struct and remove and
statements that simply set members to zero.

Link: https://lkml.kernel.org/r/20240326021656.202649-11-rick.p.edgecombe@intel.com
Link: https://lore.kernel.org/lkml/202402280912.33AEE7A9CF@keescook/#t
Link: https://lore.kernel.org/lkml/j7bfvig3gew3qruouxrh7z7ehjjafrgkbcmg6tcghhfh3rhmzi@wzlcoecgy5rs/
Link: https://lore.kernel.org/lkml/ec3e377a-c0a0-4dd3-9cb9-96517e54d17e@csgroup.eu/
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:27 -07:00
Rick Edgecombe
529ce23a76 mm: switch mm->get_unmapped_area() to a flag
The mm_struct contains a function pointer *get_unmapped_area(), which is
set to either arch_get_unmapped_area() or arch_get_unmapped_area_topdown()
during the initialization of the mm.

Since the function pointer only ever points to two functions that are
named the same across all arch's, a function pointer is not really
required.  In addition future changes will want to add versions of the
functions that take additional arguments.  So to save a pointers worth of
bytes in mm_struct, and prevent adding additional function pointers to
mm_struct in future changes, remove it and keep the information about
which get_unmapped_area() to use in a flag.

Add the new flag to MMF_INIT_MASK so it doesn't get clobbered on fork by
mmf_init_flags().  Most MM flags get clobbered on fork.  In the
pre-existing behavior mm->get_unmapped_area() would get copied to the new
mm in dup_mm(), so not clobbering the flag preserves the existing behavior
around inheriting the topdown-ness.

Introduce a helper, mm_get_unmapped_area(), to easily convert code that
refers to the old function pointer to instead select and call either
arch_get_unmapped_area() or arch_get_unmapped_area_topdown() based on the
flag.  Then drop the mm->get_unmapped_area() function pointer.  Leave the
get_unmapped_area() pointer in struct file_operations alone.  The main
purpose of this change is to reorganize in preparation for future changes,
but it also converts the calls of mm->get_unmapped_area() from indirect
branches into a direct ones.

The stress-ng bigheap benchmark calls realloc a lot, which calls through
get_unmapped_area() in the kernel.  On x86, the change yielded a ~1%
improvement there on a retpoline config.

In testing a few x86 configs, removing the pointer unfortunately didn't
result in any actual size reductions in the compiled layout of mm_struct. 
But depending on compiler or arch alignment requirements, the change could
shrink the size of mm_struct.

Link: https://lkml.kernel.org/r/20240326021656.202649-3-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:25 -07:00
Peter Xu
9636f055da mm/treewide: remove pXd_huge()
This API is not used anymore, drop it for the whole tree.

Link: https://lkml.kernel.org/r/20240318200404.448346-13-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Mark Salter <msalter@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:47 -07:00
Claudio Imbrenda
412050af2e s390/mm: Fix clearing storage keys for huge pages
The function __storage_key_init_range() expects the end address to be
the first byte outside the range to be initialized. I.e. end - start
should be the size of the area to be initialized.

The current code works because __storage_key_init_range() will still loop
over every page in the range, but it is slower than using sske_frame().

Fixes: 3afdfca698 ("s390/mm: Clear skeys for newly mapped huge guest pmds")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20240416114220.28489-3-imbrenda@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-22 12:47:47 +02:00
Claudio Imbrenda
843c328068 s390/mm: Fix storage key clearing for guest huge pages
The function __storage_key_init_range() expects the end address to be
the first byte outside the range to be initialized. I.e. end - start
should be the size of the area to be initialized.

The current code works because __storage_key_init_range() will still loop
over every page in the range, but it is slower than using sske_frame().

Fixes: 964c2c05c9 ("s390/mm: Clear huge page storage keys on enable_skey")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20240416114220.28489-2-imbrenda@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-22 12:47:47 +02:00
David Hildenbrand
06201e00ee s390/mm: Re-enable the shared zeropage for !PV and !skeys KVM guests
commit fa41ba0d08 ("s390/mm: avoid empty zero pages for KVM guests to
avoid postcopy hangs") introduced an undesired side effect when combined
with memory ballooning and VM migration: memory part of the inflated
memory balloon will consume memory.

Assuming we have a 100GiB VM and inflated the balloon to 40GiB. Our VM
will consume ~60GiB of memory. If we now trigger a VM migration,
hypervisors like QEMU will read all VM memory. As s390x does not support
the shared zeropage, we'll end up allocating for all previously-inflated
memory part of the memory balloon: 50 GiB. So we might easily
(unexpectedly) crash the VM on the migration source.

Even worse, hypervisors like QEMU optimize for zeropage migration to not
consume memory on the migration destination: when migrating a
"page full of zeroes", on the migration destination they check whether the
target memory is already zero (by reading the destination memory) and avoid
writing to the memory to not allocate memory: however, s390x will also
allocate memory here, implying that also on the migration destination, we
will end up allocating all previously-inflated memory part of the memory
balloon.

This is especially bad if actual memory overcommit was not desired, when
memory ballooning is used for dynamic VM memory resizing, setting aside
some memory during boot that can be added later on demand. Alternatives
like virtio-mem that would avoid this issue are not yet available on
s390x.

There could be ways to optimize some cases in user space: before reading
memory in an anonymous private mapping on the migration source, check via
/proc/self/pagemap if anything is already populated. Similarly check on
the migration destination before reading. While that would avoid
populating tables full of shared zeropages on all architectures, it's
harder to get right and performant, and requires user space changes.

Further, with posctopy live migration we must place a page, so there,
"avoid touching memory to avoid allocating memory" is not really
possible. (Note that a previously we would have falsely inserted
shared zeropages into processes using UFFDIO_ZEROPAGE where
mm_forbids_zeropage() would have actually forbidden it)

PV is currently incompatible with memory ballooning, and in the common
case, KVM guests don't make use of storage keys. Instead of zapping
zeropages when enabling storage keys / PV, that turned out to be
problematic in the past, let's do exactly the same we do with KSM pages:
trigger unsharing faults to replace the shared zeropages by proper
anonymous folios.

What about added latency when enabling storage kes? Having a lot of
zeropages in applicable environments (PV, legacy guests, unittests) is
unexpected. Further, KSM could today already unshare the zeropages
and unmerging KSM pages when enabling storage kets would unshare the
KSM-placed zeropages in the same way, resulting in the same latency.

[ agordeev: Fixed sparse and checkpatch complaints and error handling ]

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Fixes: fa41ba0d08 ("s390/mm: avoid empty zero pages for KVM guests to avoid postcopy hangs")
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240411161441.910170-3-david@redhat.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-18 15:02:53 +02:00
Alexander Gordeev
c98d2ecae0 s390/mm: Uncouple physical vs virtual address spaces
The uncoupling physical vs virtual address spaces brings
the following benefits to s390:

- virtual memory layout flexibility;
- closes the address gap between kernel and modules, it
  caused s390-only problems in the past (e.g. 'perf' bugs);
- allows getting rid of trampolines used for module calls
  into kernel;
- allows simplifying BPF trampoline;
- minor performance improvement in branch prediction;
- kernel randomization entropy is magnitude bigger, as it is
  derived from the amount of available virtual, not physical
  memory;

The whole change could be described in two pictures below:
before and after the change.

Some aspects of the virtual memory layout setup are not
clarified (number of page levels, alignment, DMA memory),
since these are not a part of this change or secondary
with regard to how the uncoupling itself is implemented.

The focus of the pictures is to explain why __va() and __pa()
macros are implemented the way they are.

        Memory layout in V==R mode:

|    Physical      |    Virtual       |
+- 0 --------------+- 0 --------------+ identity mapping start
|                  | S390_lowcore     | Low-address memory
|                  +- 8 KB -----------+
|                  |                  |
|                  | identity         | phys == virt
|                  | mapping          | virt == phys
|                  |                  |
+- AMODE31_START --+- AMODE31_START --+ .amode31 rand. phys/virt start
|.amode31 text/data|.amode31 text/data|
+- AMODE31_END ----+- AMODE31_END ----+ .amode31 rand. phys/virt start
|                  |                  |
|                  |                  |
+- __kaslr_offset, __kaslr_offset_phys| kernel rand. phys/virt start
|                  |                  |
| kernel text/data | kernel text/data | phys == kvirt
|                  |                  |
+------------------+------------------+ kernel phys/virt end
|                  |                  |
|                  |                  |
|                  |                  |
|                  |                  |
+- ident_map_size -+- ident_map_size -+ identity mapping end
                   |                  |
                   |  ... unused gap  |
                   |                  |
                   +---- vmemmap -----+ 'struct page' array start
                   |                  |
                   | virtually mapped |
                   | memory map       |
                   |                  |
                   +- __abs_lowcore --+
                   |                  |
                   | Absolute Lowcore |
                   |                  |
                   +- __memcpy_real_area
                   |                  |
                   |  Real Memory Copy|
                   |                  |
                   +- VMALLOC_START --+ vmalloc area start
                   |                  |
                   |  vmalloc area    |
                   |                  |
                   +- MODULES_VADDR --+ modules area start
                   |                  |
                   |  modules area    |
                   |                  |
                   +------------------+ UltraVisor Secure Storage limit
                   |                  |
                   |  ... unused gap  |
                   |                  |
                   +KASAN_SHADOW_START+ KASAN shadow memory start
                   |                  |
                   |   KASAN shadow   |
                   |                  |
                   +------------------+ ASCE limit

        Memory layout in V!=R mode:

|    Physical      |    Virtual       |
+- 0 --------------+- 0 --------------+
|                  | S390_lowcore     | Low-address memory
|                  +- 8 KB -----------+
|                  |                  |
|                  |                  |
|                  | ... unused gap   |
|                  |                  |
+- AMODE31_START --+- AMODE31_START --+ .amode31 rand. phys/virt start
|.amode31 text/data|.amode31 text/data|
+- AMODE31_END ----+- AMODE31_END ----+ .amode31 rand. phys/virt end (<2GB)
|                  |                  |
|                  |                  |
+- __kaslr_offset_phys		     | kernel rand. phys start
|                  |                  |
| kernel text/data |                  |
|                  |                  |
+------------------+		     | kernel phys end
|                  |                  |
|                  |                  |
|                  |                  |
|                  |                  |
+- ident_map_size -+		     |
                   |                  |
                   |  ... unused gap  |
                   |                  |
                   +- __identity_base + identity mapping start (>= 2GB)
                   |                  |
                   | identity         | phys == virt - __identity_base
                   | mapping          | virt == phys + __identity_base
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   |                  |
                   +---- vmemmap -----+ 'struct page' array start
                   |                  |
                   | virtually mapped |
                   | memory map       |
                   |                  |
                   +- __abs_lowcore --+
                   |                  |
                   | Absolute Lowcore |
                   |                  |
                   +- __memcpy_real_area
                   |                  |
                   |  Real Memory Copy|
                   |                  |
                   +- VMALLOC_START --+ vmalloc area start
                   |                  |
                   |  vmalloc area    |
                   |                  |
                   +- MODULES_VADDR --+ modules area start
                   |                  |
                   |  modules area    |
                   |                  |
                   +- __kaslr_offset -+ kernel rand. virt start
                   |                  |
                   | kernel text/data | phys == (kvirt - __kaslr_offset) +
                   |                  |         __kaslr_offset_phys
                   +- kernel .bss end + kernel rand. virt end
                   |                  |
                   |  ... unused gap  |
                   |                  |
                   +------------------+ UltraVisor Secure Storage limit
                   |                  |
                   |  ... unused gap  |
                   |                  |
                   +KASAN_SHADOW_START+ KASAN shadow memory start
                   |                  |
                   |   KASAN shadow   |
                   |                  |
                   +------------------+ ASCE limit

Unused gaps in the virtual memory layout could be present
or not - depending on how partucular system is configured.
No page tables are created for the unused gaps.

The relative order of vmalloc, modules and kernel image in
virtual memory is defined by following considerations:

- start of the modules area and end of the kernel should reside
  within 4GB to accommodate relative 32-bit jumps. The best way
  to achieve that is to place kernel next to modules;

- vmalloc and module areas should locate next to each other
  to prevent failures and extra reworks in user level tools
  (makedumpfile, crash, etc.) which treat vmalloc and module
  addresses similarily;

- kernel needs to be the last area in the virtual memory
  layout to easily distinguish between kernel and non-kernel
  virtual addresses. That is needed to (again) simplify
  handling of addresses in user level tools and make __pa()
  macro faster (see below);

Concluding the above, the relative order of the considered
virtual areas in memory is: vmalloc - modules - kernel.
Therefore, the only change to the current memory layout is
moving kernel to the end of virtual address space.

With that approach the implementation of __pa() macro is
straightforward - all linear virtual addresses less than
kernel base are considered identity mapping:

	phys == virt - __identity_base

All addresses greater than kernel base are kernel ones:

	phys == (kvirt - __kaslr_offset) + __kaslr_offset_phys

By contrast, __va() macro deals only with identity mapping
addresses:

	virt == phys + __identity_base

.amode31 section is mapped separately and is not covered by
__pa() macro. In fact, it could have been handled easily by
checking whether a virtual address is within the section or
not, but there is no need for that. Thus, let __pa() code
do as little machine cycles as possible.

The KASAN shadow memory is located at the very end of the
virtual memory layout, at addresses higher than the kernel.
However, that is not a linear mapping and no code other than
KASAN instrumentation or API is expected to access it.

When KASLR mode is enabled the kernel base address randomized
within a memory window that spans whole unused virtual address
space. The size of that window depends from the amount of
physical memory available to the system, the limit imposed by
UltraVisor (if present) and the vmalloc area size as provided
by vmalloc= kernel command line parameter.

In case the virtual memory is exhausted the minimum size of
the randomization window is forcefully set to 2GB, which
amounts to in 15 bits of entropy if KASAN is enabled or 17
bits of entropy in default configuration.

The default kernel offset 0x100000 is used as a magic value
both in the decompressor code and vmlinux linker script, but
it will be removed with a follow-up change.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17 13:38:01 +02:00
Alexander Gordeev
c8aef260c8 s390/boot: Swap vmalloc and Lowcore/Real Memory Copy areas
This is a preparatory rework to allow uncoupling virtual
and physical addresses spaces.

Currently the order of virtual memory areas is (the lowcore
and .amode31 section are skipped, as it is irrelevant):

	identity mapping (the kernel is contained within)
	vmemmap
	vmalloc
	modules
	Absolute Lowcore
	Real Memory Copy

In the future the kernel will be mapped separately and placed
to the end of the virtual address space, so the layout would
turn like this:

	identity mapping
	vmemmap
	vmalloc
	modules
	Absolute Lowcore
	Real Memory Copy
	kernel

However, the distance between kernel and modules needs to be as
little as possible, ideally - none. Thus, the Absolute Lowcore
and Real Memory Copy areas would stay in the way and therefore
need to be moved as well:

	identity mapping
	vmemmap
	Absolute Lowcore
	Real Memory Copy
	vmalloc
	modules
	kernel

To facilitate such layout swap the vmalloc and Absolute Lowcore
together with Real Memory Copy areas. As result, the current
layout turns into:

	identity mapping (the kernel is contained within)
	vmemmap
	Absolute Lowcore
	Real Memory Copy
	vmalloc
	modules

This will allow to locate the kernel directly next to the
modules once it gets mapped separately.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17 13:37:59 +02:00
Heiko Carstens
e6ec07dc6d s390/mm: fix NULL pointer dereference
The recently added check to figure out if a fault happened on gmap ASCE
dereferences the gmap pointer in lowcore without checking that it is not
NULL. For all non-KVM processes the pointer is NULL, so that some value
from lowcore will be read. With the current layouts of struct gmap and
struct lowcore the read value (aka ASCE) is zero, so that this doesn't lead
to any observable bug; at least currently.

Fix this by adding the missing NULL pointer check.

Fixes: 64c3431808 ("s390/entry: compare gmap asce to determine guest/host fault")
Acked-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-04-03 15:00:19 +02:00
Linus Torvalds
f9c035492f Merge tag 's390-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Heiko Carstens:

 - Various virtual vs physical address usage fixes

 - Add new bitwise types and helper functions and use them in s390
   specific drivers and code to make it easier to find virtual vs
   physical address usage bugs.

   Right now virtual and physical addresses are identical for s390,
   except for module, vmalloc, and similar areas. This will be changed,
   hopefully with the next merge window, so that e.g. the kernel image
   and modules will be located close to each other, allowing for direct
   branches and also for some other simplifications.

   As a prerequisite this requires to fix all misuses of virtual and
   physical addresses. As it turned out people are so used to the
   concept that virtual and physical addresses are the same, that new
   bugs got added to code which was already fixed. In order to avoid
   that even more code gets merged which adds such bugs add and use new
   bitwise types, so that sparse can be used to find such usage bugs.

   Most likely the new types can go away again after some time

 - Provide a simple ARCH_HAS_DEBUG_VIRTUAL implementation

 - Fix kprobe branch handling: if an out-of-line single stepped relative
   branch instruction has a target address within a certain address area
   in the entry code, the program check handler may incorrectly execute
   cleanup code as if KVM code was executed, leading to crashes

 - Fix reference counting of zcrypt card objects

 - Various other small fixes and cleanups

* tag 's390-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits)
  s390/entry: compare gmap asce to determine guest/host fault
  s390/entry: remove OUTSIDE macro
  s390/entry: add CIF_SIE flag and remove sie64a() address check
  s390/cio: use while (i--) pattern to clean up
  s390/raw3270: make class3270 constant
  s390/raw3270: improve raw3270_init() readability
  s390/tape: make tape_class constant
  s390/vmlogrdr: make vmlogrdr_class constant
  s390/vmur: make vmur_class constant
  s390/zcrypt: make zcrypt_class constant
  s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support
  s390/vfio_ccw_cp: use new address translation helpers
  s390/iucv: use new address translation helpers
  s390/ctcm: use new address translation helpers
  s390/lcs: use new address translation helpers
  s390/qeth: use new address translation helpers
  s390/zfcp: use new address translation helpers
  s390/tape: fix virtual vs physical address confusion
  s390/3270: use new address translation helpers
  s390/3215: use new address translation helpers
  ...
2024-03-19 11:38:27 -07:00
Sven Schnelle
64c3431808 s390/entry: compare gmap asce to determine guest/host fault
With the current implementation, there are some cornercases where
a host fault would be treated as a guest fault, for example
when the sie instruction causes a program check. Therefore store
the gmap asce in ptregs, and use that to compare the primary asce
from the fault instead of matching instruction addresses.

Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-03-17 19:08:50 +01:00
Linus Torvalds
902861e34c Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
   from hotplugged memory rather than only from main memory. Series
   "implement "memmap on memory" feature on s390".

 - More folio conversions from Matthew Wilcox in the series

	"Convert memcontrol charge moving to use folios"
	"mm: convert mm counter to take a folio"

 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes. The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".

 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.

 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools". Measured improvements are modest.

 - zswap cleanups and simplifications from Yosry Ahmed in the series
   "mm: zswap: simplify zswap_swapoff()".

 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is
   hotplugged as system memory.

 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.

 - More DAMON work from SeongJae Park in the series

	"mm/damon: make DAMON debugfs interface deprecation unignorable"
	"selftests/damon: add more tests for core functionalities and corner cases"
	"Docs/mm/damon: misc readability improvements"
	"mm/damon: let DAMOS feeds and tame/auto-tune itself"

 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving
   policy wherein we allocate memory across nodes in a weighted fashion
   rather than uniformly. This is beneficial in heterogeneous memory
   environments appearing with CXL.

 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".

 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format. Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.

 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
   targeted at arm64, this significantly speeds up fork() when the
   process has a large number of pte-mapped folios.

 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
   implements batching during munmap() and other pte teardown
   situations. The microbenchmark improvements are nice.

 - And in the series "Transparent Contiguous PTEs for User Mappings"
   Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings"). Kernel build times on arm64 improved nicely. Ryan's
   series "Address some contpte nits" provides some followup work.

 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page
   faults. He has also added a reproducer under the selftest code.

 - In the series "selftests/mm: Output cleanups for the compaction
   test", Mark Brown did what the title claims.

 - Kinsey Ho has added the series "mm/mglru: code cleanup and
   refactoring".

 - Even more zswap material from Nhat Pham. The series "fix and extend
   zswap kselftests" does as claimed.

 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
   in our handling of DAX on archiecctures which have virtually aliasing
   data caches. The arm architecture is the main beneficiary.

 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides
   dramatic improvements in worst-case mmap_lock hold times during
   certain userfaultfd operations.

 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series

	"page_owner: print stacks and their outstanding allocations"
	"page_owner: Fixup and cleanup"

 - Uladzislau Rezki has contributed some vmalloc scalability
   improvements in his series "Mitigate a vmap lock contention". It
   realizes a 12x improvement for a certain microbenchmark.

 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".

 - Some zsmalloc maintenance work from Chengming Zhou in the series

	"mm/zsmalloc: fix and optimize objects/page migration"
	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0. This a step along the path to implementaton of the merging
   of large anonymous folios. The series is named "Enable >0 order folio
   memory compaction".

 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages()
   to an iterator".

 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".

 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios. The
   series is named "Split a folio to any lower order folios".

 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.

 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".

 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which
   are configured to use large numbers of hugetlb pages.

 - Matthew Wilcox's series "PageFlags cleanups" does that.

 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also. S390 is affected.

 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".

 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM
   Selftests".

 - Also, of course, many singleton patches to many things. Please see
   the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
  mm/zswap: remove the memcpy if acomp is not sleepable
  crypto: introduce: acomp_is_async to expose if comp drivers might sleep
  memtest: use {READ,WRITE}_ONCE in memory scanning
  mm: prohibit the last subpage from reusing the entire large folio
  mm: recover pud_leaf() definitions in nopmd case
  selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
  selftests/mm: skip uffd hugetlb tests with insufficient hugepages
  selftests/mm: dont fail testsuite due to a lack of hugepages
  mm/huge_memory: skip invalid debugfs new_order input for folio split
  mm/huge_memory: check new folio order when split a folio
  mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
  mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
  mm: fix list corruption in put_pages_list
  mm: remove folio from deferred split list before uncharging it
  filemap: avoid unnecessary major faults in filemap_fault()
  mm,page_owner: drop unnecessary check
  mm,page_owner: check for null stack_record before bumping its refcount
  mm: swap: fix race between free_swap_and_cache() and swapoff()
  mm/treewide: align up pXd_leaf() retval across archs
  mm/treewide: drop pXd_large()
  ...
2024-03-14 17:43:30 -07:00
Heiko Carstens
5f58bde726 s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support
Provide a very simple ARCH_HAS_DEBUG_VIRTUAL implementation.
For now errors are only reported for the following cases:

- Trying to translate a vmalloc or module address to a physical address

- Translating a supposed to be ZONE_DMA virtual address into a physical
  address, and the resulting physical address is larger than two GiB

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-03-13 09:23:49 +01:00
Linus Torvalds
691632f0e8 Merge tag 's390-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Heiko Carstens:

 - Various virtual vs physical address usage fixes

 - Fix error handling in Processor Activity Instrumentation device
   driver, and export number of counters with a sysfs file

 - Allow for multiple events when Processor Activity Instrumentation
   counters are monitored in system wide sampling

 - Change multiplier and shift values of the Time-of-Day clock source to
   improve steering precision

 - Remove a couple of unneeded GFP_DMA flags from allocations

 - Disable mmap alignment if randomize_va_space is also disabled, to
   avoid a too small heap

 - Various changes to allow s390 to be compiled with LLVM=1, since
   ld.lld and llvm-objcopy will have proper s390 support witch clang 19

 - Add __uninitialized macro to Compiler Attributes. This is helpful
   with s390's FPU code where some users have up to 520 byte stack
   frames. Clearing such stack frames (if INIT_STACK_ALL_PATTERN or
   INIT_STACK_ALL_ZERO is enabled) before they are used contradicts the
   intention (performance improvement) of such code sections.

 - Convert switch_to() to an out-of-line function, and use the generic
   switch_to header file

 - Replace the usage of s390's debug feature with pr_debug() calls
   within the zcrypt device driver

 - Improve hotplug support of the Adjunct Processor device driver

 - Improve retry handling in the zcrypt device driver

 - Various changes to the in-kernel FPU code:

     - Make in-kernel FPU sections preemptible

     - Convert various larger inline assemblies and assembler files to
       C, mainly by using singe instruction inline assemblies. This
       increases readability, but also allows makes it easier to add
       proper instrumentation hooks

     - Cleanup of the header files

 - Provide fast variants of csum_partial() and
   csum_partial_copy_nocheck() based on vector instructions

 - Introduce and use a lock to synchronize accesses to zpci device data
   structures to avoid inconsistent states caused by concurrent accesses

 - Compile the kernel without -fPIE. This addresses the following
   problems if the kernel is compiled with -fPIE:

     - It uses dynamic symbols (.dynsym), for which the linker refuses
       to allow more than 64k sections. This can break features which
       use '-ffunction-sections' and '-fdata-sections', including
       kpatch-build and function granular KASLR

     - It unnecessarily uses GOT relocations, adding an extra layer of
       indirection for many memory accesses

 - Fix shared_cpu_list for CPU private L2 caches, which incorrectly were
   reported as globally shared

* tag 's390-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (117 commits)
  s390/tools: handle rela R_390_GOTPCDBL/R_390_GOTOFF64
  s390/cache: prevent rebuild of shared_cpu_list
  s390/crypto: remove retry loop with sleep from PAES pkey invocation
  s390/pkey: improve pkey retry behavior
  s390/zcrypt: improve zcrypt retry behavior
  s390/zcrypt: introduce retries on in-kernel send CPRB functions
  s390/ap: introduce mutex to lock the AP bus scan
  s390/ap: rework ap_scan_bus() to return true on config change
  s390/ap: clarify AP scan bus related functions and variables
  s390/ap: rearm APQNs bindings complete completion
  s390/configs: increase number of LOCKDEP_BITS
  s390/vfio-ap: handle hardware checkstop state on queue reset operation
  s390/pai: change sampling event assignment for PMU device driver
  s390/boot: fix minor comment style damages
  s390/boot: do not check for zero-termination relocation entry
  s390/boot: make type of __vmlinux_relocs_64_start|end consistent
  s390/boot: sanitize kaslr_adjust_relocs() function prototype
  s390/boot: simplify GOT handling
  s390: vmlinux.lds.S: fix .got.plt assertion
  s390/boot: workaround current 'llvm-objdump -t -j ...' behavior
  ...
2024-03-12 10:14:22 -07:00
Peter Xu
0a845e0f63 mm/treewide: replace pud_large() with pud_leaf()
pud_large() is always defined as pud_leaf().  Merge their usages.  Chose
pud_leaf() because pud_leaf() is a global API, while pud_large() is not.

Link: https://lkml.kernel.org/r/20240305043750.93762-9-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06 13:04:19 -08:00
Peter Xu
2f709f7bfd mm/treewide: replace pmd_large() with pmd_leaf()
pmd_large() is always defined as pmd_leaf().  Merge their usages.  Chose
pmd_leaf() because pmd_leaf() is a global API, while pmd_large() is not.

Link: https://lkml.kernel.org/r/20240305043750.93762-8-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06 13:04:19 -08:00