Commit Graph

90 Commits

Author SHA1 Message Date
Linus Torvalds
12952b6bbd LoongArch changes for v6.6
1, Allow usage of LSX/LASX in the kernel;
 2, Add SIMD-optimized RAID5/RAID6 routines;
 3, Add Loongson Binary Translation (LBT) extension support;
 4, Add basic KGDB & KDB support;
 5, Add building with kcov coverage;
 6, Add KFENCE (Kernel Electric-Fence) support;
 7, Add KASAN (Kernel Address Sanitizer) support;
 8, Some bug fixes and other small changes;
 9, Update the default config file.
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCAA0FiEEzOlt8mkP+tbeiYy5AoYrw/LiJnoFAmT5TfMWHGNoZW5odWFj
 YWlAa2VybmVsLm9yZwAKCRAChivD8uImeqd3EACjqCaHNlp33kwufSPpGuQw9a8I
 F7JW1KzBOoWELch5nFRjfQClROBWRmM4jN5YnxENBQ5K2F1K6gfxdkfjew+KV2mn
 ki9ByamCfFVJDZXo9wavUD2LBrVakEFmLT+SyXBxdWwJ3fDivHjF6A0qs9ltp7dq
 Bttq4bkw1mZsU6MnViRwPKVROtNUVrd9mwYSTq0iXviVEbWhPHQQTxRizNra9Z6X
 7XWxO0ODHl0WVvdOJU+F16mBRS3Bs1g/HHAIDc41yrYEHFFOeFCEUAQSF/4Nj5wj
 BAfAB8WOa9+vPH8fTnrpCt2RtGJmkz71TM49DdXB7jpGaWIyc4WDi9MXeeBiJ0wE
 vQg8IECc9POC1sH4/6BMwq2qkrWRj2PYFYof0fP66iWNjmodtNUf7GOVHy8MTQan
 xHWizJFAdY/u/bwbF9tRQ+EVeot/844CkjtZxkgTfV8shN6kCMEVAamwBItZ7TXN
 g/oc1ORM6nsKHBDQF3r2LSY0Gbf3OSfMJVL8SLEQ9hAhgGhotmJ36B4bdvyO7T0Q
 gNn//U+p4IIMFRKRxreEz9P0KjTOJrHAAxNzu1oZebhGZd5WI+i0PHYkkBDKZTXc
 7qaEdM2cX8Wd0ePIXOHQnSItwYO7ilrviHyeCM8wd/g2/W/00jvnpF3J+2rk7eJO
 rcfAr8+V5ylYBQzp6Q==
 =NXy2
 -----END PGP SIGNATURE-----

Merge tag 'loongarch-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch updates from Huacai Chen:

 - Allow usage of LSX/LASX in the kernel, and use them for
   SIMD-optimized RAID5/RAID6 routines

 - Add Loongson Binary Translation (LBT) extension support

 - Add basic KGDB & KDB support

 - Add building with kcov coverage

 - Add KFENCE (Kernel Electric-Fence) support

 - Add KASAN (Kernel Address Sanitizer) support

 - Some bug fixes and other small changes

 - Update the default config file

* tag 'loongarch-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (25 commits)
  LoongArch: Update Loongson-3 default config file
  LoongArch: Add KASAN (Kernel Address Sanitizer) support
  LoongArch: Simplify the processing of jumping new kernel for KASLR
  kasan: Add (pmd|pud)_init for LoongArch zero_(pud|p4d)_populate process
  kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping
  LoongArch: Add KFENCE (Kernel Electric-Fence) support
  LoongArch: Get partial stack information when providing regs parameter
  LoongArch: mm: Add page table mapped mode support for virt_to_page()
  kfence: Defer the assignment of the local variable addr
  LoongArch: Allow building with kcov coverage
  LoongArch: Provide kaslr_offset() to get kernel offset
  LoongArch: Add basic KGDB & KDB support
  LoongArch: Add Loongson Binary Translation (LBT) extension support
  raid6: Add LoongArch SIMD recovery implementation
  raid6: Add LoongArch SIMD syndrome calculation
  LoongArch: Add SIMD-optimized XOR routines
  LoongArch: Allow usage of LSX/LASX in the kernel
  LoongArch: Define symbol 'fault' as a local label in fpu.S
  LoongArch: Adjust {copy, clear}_user exception handler behavior
  LoongArch: Use static defined zero page rather than allocated
  ...
2023-09-08 12:16:52 -07:00
Enze Li
ec9fee79d4 kfence: Defer the assignment of the local variable addr
The LoongArch architecture is different from other architectures. It
needs to update __kfence_pool during arch_kfence_init_pool().

This patch modifies the assignment location of the local variable addr
in the kfence_init_pool() function to support the case of updating
__kfence_pool in arch_kfence_init_pool().

Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Enze Li <lienze@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 22:53:55 +08:00
Linus Torvalds
d68b4b6f30 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
("refactor Kconfig to consolidate KEXEC and CRASH options").
 
 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h").
 
 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands").
 
 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions").
 
 - Switch the handling of kdump from a udev scheme to in-kernel handling,
   by Eric DeVolder ("crash: Kernel handling of CPU and memory hot
   un/plug").
 
 - Many singleton patches to various parts of the tree
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZO2GpAAKCRDdBJ7gKXxA
 juW3AQD1moHzlSN6x9I3tjm5TWWNYFoFL8af7wXDJspp/DWH/AD/TO0XlWWhhbYy
 QHy7lL0Syha38kKLMXTM+bN6YQHi9AU=
 =WJQa
 -----END PGP SIGNATURE-----

Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
   ("refactor Kconfig to consolidate KEXEC and CRASH options")

 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h")

 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands")

 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions")

 - Switch the handling of kdump from a udev scheme to in-kernel
   handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
   hot un/plug")

 - Many singleton patches to various parts of the tree

* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
  document while_each_thread(), change first_tid() to use for_each_thread()
  drivers/char/mem.c: shrink character device's devlist[] array
  x86/crash: optimize CPU changes
  crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
  crash: hotplug support for kexec_load()
  x86/crash: add x86 crash hotplug support
  crash: memory and CPU hotplug sysfs attributes
  kexec: exclude elfcorehdr from the segment digest
  crash: add generic infrastructure for crash hotplug support
  crash: move a few code bits to setup support of crash hotplug
  kstrtox: consistently use _tolower()
  kill do_each_thread()
  nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
  scripts/bloat-o-meter: count weak symbol sizes
  treewide: drop CONFIG_EMBEDDED
  lockdep: fix static memory detection even more
  lib/vsprintf: declare no_hash_pointers in sprintf.h
  lib/vsprintf: split out sprintf() and friends
  kernel/fork: stop playing lockless games for exe_file replacement
  adfs: delete unused "union adfs_dirtail" definition
  ...
2023-08-29 14:53:51 -07:00
Linus Torvalds
b96a3e9142 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list")
- Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP.  It
   also speeds up GUP handling of transparent hugepages.
 
 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").
 
 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").
 
 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").
 
 - xu xin has doe some work on KSM's handling of zero pages.  These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support tracking
   KSM-placed zero-pages").
 
 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").
 
 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").
 
 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with UFFD").
 
 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").
 
 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").
 
 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").
 
 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").
 
 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").
 
 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap").  And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").
 
 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").
 
 - Baoquan He has converted some architectures to use the GENERIC_IOREMAP
   ioremap()/iounmap() code ("mm: ioremap: Convert architectures to take
   GENERIC_IOREMAP way").
 
 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").
 
 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep").  Liam also developed some efficiency improvements
   ("Reduce preallocations for maple tree").
 
 - Cleanup and optimization to the secondary IOMMU TLB invalidation, from
   Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").
 
 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").
 
 - Kemeng Shi provides some maintenance work on the compaction code ("Two
   minor cleanups for compaction").
 
 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle most
   file-backed faults under the VMA lock").
 
 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").
 
 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").
 
 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").
 
 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").
 
 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").
 
 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").
 
 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").
 
 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").
 
 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").
 
 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for memmap
   on memory feature on ppc64").
 
 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock migratetype").
 
 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").
 
 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").
 
 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").
 
 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").
 
 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").
 
 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").
 
 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").
 
 - pagetable handling cleanups from Matthew Wilcox ("New page table range
   API").
 
 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").
 
 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").
 
 - Matthew Wilcox has also done some maintenance work on the MM subsystem
   documentation ("Improve mm documentation").
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZO1JUQAKCRDdBJ7gKXxA
 jrMwAP47r/fS8vAVT3zp/7fXmxaJYTK27CTAM881Gw1SDhFM/wEAv8o84mDenCg6
 Nfio7afS1ncD+hPYT8947UnLxTgn+ww=
 =Afws
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in
   add_to_avail_list")

 - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP. It
   also speeds up GUP handling of transparent hugepages.

 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").

 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").

 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").

 - xu xin has doe some work on KSM's handling of zero pages. These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support
   tracking KSM-placed zero-pages").

 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").

 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").

 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with
   UFFD").

 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").

 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").

 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").

 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").

 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").

 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap"). And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").

 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").

 - Baoquan He has converted some architectures to use the
   GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
   architectures to take GENERIC_IOREMAP way").

 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").

 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep"). Liam also developed some efficiency
   improvements ("Reduce preallocations for maple tree").

 - Cleanup and optimization to the secondary IOMMU TLB invalidation,
   from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").

 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").

 - Kemeng Shi provides some maintenance work on the compaction code
   ("Two minor cleanups for compaction").

 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
   most file-backed faults under the VMA lock").

 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").

 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").

 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").

 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").

 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").

 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").

 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").

 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").

 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").

 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
   memmap on memory feature on ppc64").

 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock
   migratetype").

 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").

 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").

 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").

 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").

 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").

 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").

 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").

 - pagetable handling cleanups from Matthew Wilcox ("New page table
   range API").

 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").

 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").

 - Matthew Wilcox has also done some maintenance work on the MM
   subsystem documentation ("Improve mm documentation").

* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
  maple_tree: shrink struct maple_tree
  maple_tree: clean up mas_wr_append()
  secretmem: convert page_is_secretmem() to folio_is_secretmem()
  nios2: fix flush_dcache_page() for usage from irq context
  hugetlb: add documentation for vma_kernel_pagesize()
  mm: add orphaned kernel-doc to the rst files.
  mm: fix clean_record_shared_mapping_range kernel-doc
  mm: fix get_mctgt_type() kernel-doc
  mm: fix kernel-doc warning from tlb_flush_rmaps()
  mm: remove enum page_entry_size
  mm: allow ->huge_fault() to be called without the mmap_lock held
  mm: move PMD_ORDER to pgtable.h
  mm: remove checks for pte_index
  memcg: remove duplication detection for mem_cgroup_uncharge_swap
  mm/huge_memory: work on folio->swap instead of page->private when splitting folio
  mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
  mm/swap: use dedicated entry for swap in folio
  mm/swap: stop using page->private on tail pages for THP_SWAP
  selftests/mm: fix WARNING comparing pointer to 0
  selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
  ...
2023-08-29 14:25:26 -07:00
Andy Shevchenko
6655360923 lib/vsprintf: declare no_hash_pointers in sprintf.h
Sparse is not happy to see non-static variable without declaration:
lib/vsprintf.c:61:6: warning: symbol 'no_hash_pointers' was not declared. 
Should it be static?

Declare respective variable in the sprintf.h.  With this, add a comment to
discourage its use if no real need.

Link: https://lkml.kernel.org/r/20230814163344.17429-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:46:24 -07:00
Peng Zhang
cabdf74e6b mm: kfence: allocate kfence_metadata at runtime
kfence_metadata is currently a static array.  For the purpose of
allocating scalable __kfence_pool, we first change it to runtime
allocation of metadata.  Since the size of an object of kfence_metadata is
1160 bytes, we can save at least 72 pages (with default 256 objects)
without enabling kfence.

[akpm@linux-foundation.org: restore newline, per Marco]
Link: https://lkml.kernel.org/r/20230718073019.52513-1-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:12:39 -07:00
GONG, Ruiqi
3c61529405 Randomized slab caches for kmalloc()
When exploiting memory vulnerabilities, "heap spraying" is a common
technique targeting those related to dynamic memory allocation (i.e. the
"heap"), and it plays an important role in a successful exploitation.
Basically, it is to overwrite the memory area of vulnerable object by
triggering allocation in other subsystems or modules and therefore
getting a reference to the targeted memory location. It's usable on
various types of vulnerablity including use after free (UAF), heap out-
of-bound write and etc.

There are (at least) two reasons why the heap can be sprayed: 1) generic
slab caches are shared among different subsystems and modules, and
2) dedicated slab caches could be merged with the generic ones.
Currently these two factors cannot be prevented at a low cost: the first
one is a widely used memory allocation mechanism, and shutting down slab
merging completely via `slub_nomerge` would be overkill.

To efficiently prevent heap spraying, we propose the following approach:
to create multiple copies of generic slab caches that will never be
merged, and random one of them will be used at allocation. The random
selection is based on the address of code that calls `kmalloc()`, which
means it is static at runtime (rather than dynamically determined at
each time of allocation, which could be bypassed by repeatedly spraying
in brute force). In other words, the randomness of cache selection will
be with respect to the code address rather than time, i.e. allocations
in different code paths would most likely pick different caches,
although kmalloc() at each place would use the same cache copy whenever
it is executed. In this way, the vulnerable object and memory allocated
in other subsystems and modules will (most probably) be on different
slab caches, which prevents the object from being sprayed.

Meanwhile, the static random selection is further enhanced with a
per-boot random seed, which prevents the attacker from finding a usable
kmalloc that happens to pick the same cache with the vulnerable
subsystem/module by analyzing the open source code. In other words, with
the per-boot seed, the random selection is static during each time the
system starts and runs, but not across different system startups.

The overhead of performance has been tested on a 40-core x86 server by
comparing the results of `perf bench all` between the kernels with and
without this patch based on the latest linux-next kernel, which shows
minor difference. A subset of benchmarks are listed below:

                sched/  sched/  syscall/       mem/       mem/
             messaging    pipe     basic     memcpy     memset
                 (sec)   (sec)     (sec)   (GB/sec)   (GB/sec)

control1         0.019   5.459     0.733  15.258789  51.398026
control2         0.019   5.439     0.730  16.009221  48.828125
control3         0.019   5.282     0.735  16.009221  48.828125
control_avg      0.019   5.393     0.733  15.759077  49.684759

experiment1      0.019   5.374     0.741  15.500992  46.502976
experiment2      0.019   5.440     0.746  16.276042  51.398026
experiment3      0.019   5.242     0.752  15.258789  51.398026
experiment_avg   0.019   5.352     0.746  15.678608  49.766343

The overhead of memory usage was measured by executing `free` after boot
on a QEMU VM with 1GB total memory, and as expected, it's positively
correlated with # of cache copies:

           control  4 copies  8 copies  16 copies

total       969.8M    968.2M    968.2M     968.2M
used         20.0M     21.9M     24.1M      26.7M
free        936.9M    933.6M    931.4M     928.6M
available   932.2M    928.8M    926.6M     923.9M

Co-developed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: GONG, Ruiqi <gongruiqi@huaweicloud.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: Dennis Zhou <dennis@kernel.org> # percpu
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2023-07-18 10:07:47 +02:00
Jesper Dangaard Brouer
d0bf7d5759 mm/slab: introduce kmem_cache flag SLAB_NO_MERGE
Allow API users of kmem_cache_create to specify that they don't want
any slab merge or aliasing (with similar sized objects). Use this in
kfence_test.

The SKB (sk_buff) kmem_cache slab is critical for network performance.
Network stack uses kmem_cache_{alloc,free}_bulk APIs to gain
performance by amortising the alloc/free cost.

For the bulk API to perform efficiently the slub fragmentation need to
be low. Especially for the SLUB allocator, the efficiency of bulk free
API depend on objects belonging to the same slab (page).

When running different network performance microbenchmarks, I started
to notice that performance was reduced (slightly) when machines had
longer uptimes. I believe the cause was 'skbuff_head_cache' got
aliased/merged into the general slub for 256 bytes sized objects (with
my kernel config, without CONFIG_HARDENED_USERCOPY).

For SKB kmem_cache network stack have reasons for not merging, but it
varies depending on kernel config (e.g. CONFIG_HARDENED_USERCOPY).
We want to explicitly set SLAB_NO_MERGE for this kmem_cache.

Another use case for the flag has been described by David Sterba [1]:

> This can be used for more fine grained control over the caches or for
> debugging builds where separate slabs can verify that no objects leak.

> The slab_nomerge boot option is too coarse and would need to be
> enabled on all testing hosts. There are some other ways how to disable
> merging, e.g. a slab constructor but this disables poisoning besides
> that it adds additional overhead. Other flags are internal and may
> have other semantics.

> A concrete example what motivates the flag. During 'btrfs balance'
> slab top reported huge increase in caches like

>  1330095 1330095 100%    0.10K  34105       39    136420K Acpi-ParseExt
>  1734684 1734684 100%    0.14K  61953       28    247812K pid_namespace
>  8244036 6873075  83%    0.11K 229001       36    916004K khugepaged_mm_slot

> which was confusing and that it's because of slab merging was not the
> first idea.  After rebooting with slab_nomerge all the caches were
> from btrfs_ namespace as expected.

[1] https://lore.kernel.org/all/20230524101748.30714-1-dsterba@suse.com/

[ vbabka@suse.cz: rename to SLAB_NO_MERGE, change the flag value to the
  one proposed by David so it does not collide with internal SLAB/SLUB
  flags, write a comment for the flag, expand changelog, drop the skbuff
  part to be handled spearately ]

Link: https://lore.kernel.org/all/167396280045.539803.7540459812377220500.stgit@firesoul/
Reported-by: David Sterba <dsterba@suse.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
2023-06-02 10:24:33 +02:00
Michael Ellerman
7581495ac8 mm: kfence: fix false positives on big endian
Since commit 1ba3cbf3ec ("mm: kfence: improve the performance of
__kfence_alloc() and __kfence_free()"), kfence reports failures in random
places at boot on big endian machines.

The problem is that the new KFENCE_CANARY_PATTERN_U64 encodes the address
of each byte in its value, so it needs to be byte swapped on big endian
machines.

The compiler is smart enough to do the le64_to_cpu() at compile time, so
there is no runtime overhead.

Link: https://lkml.kernel.org/r/20230505035127.195387-1-mpe@ellerman.id.au
Fixes: 1ba3cbf3ec ("mm: kfence: improve the performance of __kfence_alloc() and __kfence_free()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-17 15:24:33 -07:00
Linus Torvalds
7fa8a8ee94 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
 
 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav.
 
 - zsmalloc performance improvements from Sergey Senozhatsky.
 
 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.
 
 - VFS rationalizations from Christoph Hellwig:
 
   - removal of most of the callers of write_one_page().
 
   - make __filemap_get_folio()'s return value more useful
 
 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing.  Use `mount -o noswap'.
 
 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.
 
 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).
 
 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.
 
 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather
   than exclusive, and has fixed a bunch of errors which were caused by its
   unintuitive meaning.
 
 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.
 
 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.
 
 - Cleanups to do_fault_around() by Lorenzo Stoakes.
 
 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.
 
 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.
 
 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.
 
 - Lorenzo has also contributed further cleanups of vma_merge().
 
 - Chaitanya Prakash provides some fixes to the mmap selftesting code.
 
 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.
 
 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.
 
 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.
 
 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.
 
 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.
 
 - Yosry Ahmed has improved the performance of memcg statistics flushing.
 
 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.
 
 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.
 
 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.
 
 - Pankaj Raghav has made page_endio() unneeded and has removed it.
 
 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.
 
 - Yosry Ahmed has fixed an issue around memcg's page recalim accounting.
 
 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.
 
 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.
 
 - Peter Xu fixes a few issues with uffd-wp at fork() time.
 
 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZEr3zQAKCRDdBJ7gKXxA
 jlLoAP0fpQBipwFxED0Us4SKQfupV6z4caXNJGPeay7Aj11/kQD/aMRC2uPfgr96
 eMG3kwn2pqkB9ST2QpkaRbxA//eMbQY=
 =J+Dj
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...
2023-04-27 19:42:02 -07:00
Linus Torvalds
df45da57cb arm64 updates for 6.4
ACPI:
 	* Improve error reporting when failing to manage SDEI on AGDI device
 	  removal
 
 Assembly routines:
 	* Improve register constraints so that the compiler can make use of
 	  the zero register instead of moving an immediate #0 into a GPR
 
 	* Allow the compiler to allocate the registers used for CAS
 	  instructions
 
 CPU features and system registers:
 	* Cleanups to the way in which CPU features are identified from the
 	  ID register fields
 
 	* Extend system register definition generation to handle Enum types
 	  when defining shared register fields
 
 	* Generate definitions for new _EL2 registers and add new fields
 	  for ID_AA64PFR1_EL1
 
 	* Allow SVE to be disabled separately from SME on the kernel
 	  command-line
 
 Tracing:
 	* Support for "direct calls" in ftrace, which enables BPF tracing
 	  for arm64
 
 Kdump:
 	* Don't bother unmapping the crashkernel from the linear mapping,
 	  which then allows us to use huge (block) mappings and reduce
 	  TLB pressure when a crashkernel is loaded.
 
 Memory management:
 	* Try again to remove data cache invalidation from the coherent DMA
 	  allocation path
 
 	* Simplify the fixmap code by mapping at page granularity
 
 	* Allow the kfence pool to be allocated early, preventing the rest
 	  of the linear mapping from being forced to page granularity
 
 Perf and PMU:
 	* Move CPU PMU code out to drivers/perf/ where it can be reused
 	  by the 32-bit ARM architecture when running on ARMv8 CPUs
 
 	* Fix race between CPU PMU probing and pKVM host de-privilege
 
 	* Add support for Apple M2 CPU PMU
 
 	* Adjust the generic PERF_COUNT_HW_BRANCH_INSTRUCTIONS event
 	  dynamically, depending on what the CPU actually supports
 
 	* Minor fixes and cleanups to system PMU drivers
 
 Stack tracing:
 	* Use the XPACLRI instruction to strip PAC from pointers, rather
 	  than rolling our own function in C
 
 	* Remove redundant PAC removal for toolchains that handle this in
 	  their builtins
 
 	* Make backtracing more resilient in the face of instrumentation
 
 Miscellaneous:
 	* Fix single-step with KGDB
 
 	* Remove harmless warning when 'nokaslr' is passed on the kernel
 	  command-line
 
 	* Minor fixes and cleanups across the board
 -----BEGIN PGP SIGNATURE-----
 
 iQFEBAABCgAuFiEEPxTL6PPUbjXGY88ct6xw3ITBYzQFAmRChcwQHHdpbGxAa2Vy
 bmVsLm9yZwAKCRC3rHDchMFjNCgBCADFvkYY9ESztSnd3EpiMbbAzgRCQBiA5H7U
 F2Wc+hIWgeAeUEttSH22+F16r6Jb0gbaDvsuhtN2W/rwQhKNbCU0MaUME05MPmg2
 AOp+RZb2vdT5i5S5dC6ZM6G3T6u9O78LBWv2JWBdd6RIybamEn+RL00ep2WAduH7
 n1FgTbsKgnbScD2qd4K1ejZ1W/BQMwYulkNpyTsmCIijXM12lkzFlxWnMtky3uhR
 POpawcIZzXvWI02QAX+SIdynGChQV3VP+dh9GuFbt7ASigDEhgunvfUYhZNSaqf4
 +/q0O8toCtmQJBUhF0DEDSB5T8SOz5v9CKxKuwfaX6Trq0ixFQpZ
 =78L9
 -----END PGP SIGNATURE-----

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "ACPI:

   - Improve error reporting when failing to manage SDEI on AGDI device
     removal

  Assembly routines:

   - Improve register constraints so that the compiler can make use of
     the zero register instead of moving an immediate #0 into a GPR

   - Allow the compiler to allocate the registers used for CAS
     instructions

  CPU features and system registers:

   - Cleanups to the way in which CPU features are identified from the
     ID register fields

   - Extend system register definition generation to handle Enum types
     when defining shared register fields

   - Generate definitions for new _EL2 registers and add new fields for
     ID_AA64PFR1_EL1

   - Allow SVE to be disabled separately from SME on the kernel
     command-line

  Tracing:

   - Support for "direct calls" in ftrace, which enables BPF tracing for
     arm64

  Kdump:

   - Don't bother unmapping the crashkernel from the linear mapping,
     which then allows us to use huge (block) mappings and reduce TLB
     pressure when a crashkernel is loaded.

  Memory management:

   - Try again to remove data cache invalidation from the coherent DMA
     allocation path

   - Simplify the fixmap code by mapping at page granularity

   - Allow the kfence pool to be allocated early, preventing the rest of
     the linear mapping from being forced to page granularity

  Perf and PMU:

   - Move CPU PMU code out to drivers/perf/ where it can be reused by
     the 32-bit ARM architecture when running on ARMv8 CPUs

   - Fix race between CPU PMU probing and pKVM host de-privilege

   - Add support for Apple M2 CPU PMU

   - Adjust the generic PERF_COUNT_HW_BRANCH_INSTRUCTIONS event
     dynamically, depending on what the CPU actually supports

   - Minor fixes and cleanups to system PMU drivers

  Stack tracing:

   - Use the XPACLRI instruction to strip PAC from pointers, rather than
     rolling our own function in C

   - Remove redundant PAC removal for toolchains that handle this in
     their builtins

   - Make backtracing more resilient in the face of instrumentation

  Miscellaneous:

   - Fix single-step with KGDB

   - Remove harmless warning when 'nokaslr' is passed on the kernel
     command-line

   - Minor fixes and cleanups across the board"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (72 commits)
  KVM: arm64: Ensure CPU PMU probes before pKVM host de-privilege
  arm64: kexec: include reboot.h
  arm64: delete dead code in this_cpu_set_vectors()
  arm64/cpufeature: Use helper macro to specify ID register for capabilites
  drivers/perf: hisi: add NULL check for name
  drivers/perf: hisi: Remove redundant initialized of pmu->name
  arm64/cpufeature: Consistently use symbolic constants for min_field_value
  arm64/cpufeature: Pull out helper for CPUID register definitions
  arm64/sysreg: Convert HFGITR_EL2 to automatic generation
  ACPI: AGDI: Improve error reporting for problems during .remove()
  arm64: kernel: Fix kernel warning when nokaslr is passed to commandline
  perf/arm-cmn: Fix port detection for CMN-700
  arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step
  arm64: move PAC masks to <asm/pointer_auth.h>
  arm64: use XPACLRI to strip PAC
  arm64: avoid redundant PAC stripping in __builtin_return_address()
  arm64/sme: Fix some comments of ARM SME
  arm64/signal: Alloc tpidr2 sigframe after checking system_supports_tpidr2()
  arm64/signal: Use system_supports_tpidr2() to check TPIDR2
  arm64/idreg: Don't disable SME when disabling SVE
  ...
2023-04-25 12:39:01 -07:00
Pavankumar Kondeti
1f6ab566cb printk: export console trace point for kcsan/kasan/kfence/kmsan
The console tracepoint is used by kcsan/kasan/kfence/kmsan test modules. 
Since this tracepoint is not exported, these modules iterate over all
available tracepoints to find the console trace point.  Export the trace
point so that it can be directly used.

Link: https://lkml.kernel.org/r/20230413100859.1492323-1-quic_pkondeti@quicinc.com
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Marco Elver <elver@google.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:30:11 -07:00
Peng Zhang
1ba3cbf3ec mm: kfence: improve the performance of __kfence_alloc() and __kfence_free()
In __kfence_alloc() and __kfence_free(), we will set and check canary. 
Assuming that the size of the object is close to 0, nearly 4k memory
accesses are required because setting and checking canary is executed byte
by byte.

canary is now defined like this:
KFENCE_CANARY_PATTERN(addr) ((u8)0xaa ^ (u8)((unsigned long)(addr) & 0x7))

Observe that canary is only related to the lower three bits of the
address, so every 8 bytes of canary are the same.  We can access 8-byte
canary each time instead of byte-by-byte, thereby optimizing nearly 4k
memory accesses to 4k/8 times.

Use the bcc tool funclatency to measure the latency of __kfence_alloc()
and __kfence_free(), the numbers (deleted the distribution of latency) is
posted below.  Though different object sizes will have an impact on the
measurement, we ignore it for now and assume the average object size is
roughly equal.

Before patching:
__kfence_alloc:
avg = 5055 nsecs, total: 5515252 nsecs, count: 1091
__kfence_free:
avg = 5319 nsecs, total: 9735130 nsecs, count: 1830

After patching:
__kfence_alloc:
avg = 3597 nsecs, total: 6428491 nsecs, count: 1787
__kfence_free:
avg = 3046 nsecs, total: 3415390 nsecs, count: 1121

The numbers indicate that there is ~30% - ~40% performance improvement.

Link: https://lkml.kernel.org/r/20230403122738.6006-1-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:49 -07:00
Muchun Song
1f2803b266 mm: kfence: fix handling discontiguous page
The struct pages could be discontiguous when the kfence pool is allocated
via alloc_contig_pages() with CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP.

This may result in setting PG_slab and memcg_data to a arbitrary
address (may be not used as a struct page), which in the worst case
might corrupt the kernel.

So the iteration should use nth_page().

Link: https://lkml.kernel.org/r/20230323025003.94447-1-songmuchun@bytedance.com
Fixes: 0ce20dd840 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-28 15:24:32 -07:00
Muchun Song
3ee2d7471f mm: kfence: fix PG_slab and memcg_data clearing
It does not reset PG_slab and memcg_data when KFENCE fails to initialize
kfence pool at runtime.  It is reporting a "Bad page state" message when
kfence pool is freed to buddy.  The checking of whether it is a compound
head page seems unnecessary since we already guarantee this when
allocating kfence pool.   Remove the check to simplify the code.

Link: https://lkml.kernel.org/r/20230320030059.20189-1-songmuchun@bytedance.com
Fixes: 0ce20dd840 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-28 15:24:32 -07:00
Zhenhua Huang
bfa7965b33 mm,kfence: decouple kfence from page granularity mapping judgement
Kfence only needs its pool to be mapped as page granularity, if it is
inited early. Previous judgement was a bit over protected. From [1], Mark
suggested to "just map the KFENCE region a page granularity". So I
decouple it from judgement and do page granularity mapping for kfence
pool only. Need to be noticed that late init of kfence pool still requires
page granularity mapping.

Page granularity mapping in theory cost more(2M per 1GB) memory on arm64
platform. Like what I've tested on QEMU(emulated 1GB RAM) with
gki_defconfig, also turning off rodata protection:
Before:
[root@liebao ]# cat /proc/meminfo
MemTotal:         999484 kB
After:
[root@liebao ]# cat /proc/meminfo
MemTotal:        1001480 kB

To implement this, also relocate the kfence pool allocation before the
linear mapping setting up, arm64_kfence_alloc_pool is to allocate phys
addr, __kfence_pool is to be set after linear mapping set up.

LINK: [1] https://lore.kernel.org/linux-arm-kernel/Y+IsdrvDNILA59UN@FVFF77S0Q05N/
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/1679066974-690-1-git-send-email-quic_zhenhuah@quicinc.com
Signed-off-by: Will Deacon <will@kernel.org>
2023-03-27 16:15:20 +01:00
Marco Elver
2e08ca1802 kfence: avoid passing -g for test
Nathan reported that when building with GNU as and a version of clang that
defaults to DWARF5:

  $ make -skj"$(nproc)" ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \
			LLVM=1 LLVM_IAS=0 O=build \
			mrproper allmodconfig mm/kfence/kfence_test.o
  /tmp/kfence_test-08a0a0.s: Assembler messages:
  /tmp/kfence_test-08a0a0.s:14627: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14628: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14632: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14633: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14639: Error: non-constant .uleb128 is not supported
  ...

This is because `-g` defaults to the compiler debug info default.  If the
assembler does not support some of the directives used, the above errors
occur.  To fix, remove the explicit passing of `-g`.

All the test wants is that stack traces print valid function names, and
debug info is not required for that.  (I currently cannot recall why I
added the explicit `-g`.)

Link: https://lkml.kernel.org/r/20230316224705.709984-1-elver@google.com
Fixes: bc8fbc5f30 ("kfence: add test suite")
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-23 17:18:35 -07:00
Muchun Song
1c86a188e0 mm: kfence: fix using kfence_metadata without initialization in show_object()
The variable kfence_metadata is initialized in kfence_init_pool(), then,
it is not initialized if kfence is disabled after booting.  In this case,
kfence_metadata will be used (e.g.  ->lock and ->state fields) without
initialization when reading /sys/kernel/debug/kfence/objects.  There will
be a warning if you enable CONFIG_DEBUG_SPINLOCK.  Fix it by creating
debugfs files when necessary.

Link: https://lkml.kernel.org/r/20230315034441.44321-1-songmuchun@bytedance.com
Fixes: 0ce20dd840 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Tested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-23 17:18:35 -07:00
Linus Torvalds
48ea09cdda hardening updates for v6.2-rc1
- Convert flexible array members, fix -Wstringop-overflow warnings,
   and fix KCFI function type mismatches that went ignored by
   maintainers (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook).
 
 - Remove the remaining side-effect users of ksize() by converting
   dma-buf, btrfs, and coredump to using kmalloc_size_roundup(),
   add more __alloc_size attributes, and introduce full testing
   of all allocator functions. Finally remove the ksize() side-effect
   so that each allocation-aware checker can finally behave without
   exceptions.
 
 - Introduce oops_limit (default 10,000) and warn_limit (default off)
   to provide greater granularity of control for panic_on_oops and
   panic_on_warn (Jann Horn, Kees Cook).
 
 - Introduce overflows_type() and castable_to_type() helpers for
   cleaner overflow checking.
 
 - Improve code generation for strscpy() and update str*() kern-doc.
 
 - Convert strscpy and sigphash tests to KUnit, and expand memcpy
   tests.
 
 - Always use a non-NULL argument for prepare_kernel_cred().
 
 - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell).
 
 - Adjust orphan linker section checking to respect CONFIG_WERROR
   (Xin Li).
 
 - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu).
 
 - Fix um vs FORTIFY warnings for always-NULL arguments.
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmOZSOoWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJjAAD/0YkvpU7f03f8hcQMJK6wv//24K
 AW41hEaBikq9RcmkuvkLLrJRibGgZ5O2xUkUkxRs/HxhkhrZ0kEw8sbwZe8MoWls
 F4Y9+TDjsrdHmjhfcBZdLnVxwcKK5wlaEcpjZXtbsfcdhx3TbgcDA23YELl5t0K+
 I11j4kYmf9SLl4CwIrSP5iACml8CBHARDh8oIMF7FT/LrjNbM8XkvBcVVT6hTbOV
 yjgA8WP2e9GXvj9GzKgqvd0uE/kwPkVAeXLNFWopPi4FQ8AWjlxbBZR0gamA6/EB
 d7TIs0ifpVU2JGQaTav4xO6SsFMj3ntoUI0qIrFaTxZAvV4KYGrPT/Kwz1O4SFaG
 rN5lcxseQbPQSBTFNG4zFjpywTkVCgD2tZqDwz5Rrmiraz0RyIokCN+i4CD9S0Ds
 oEd8JSyLBk1sRALczkuEKo0an5AyC9YWRcBXuRdIHpLo08PsbeUUSe//4pe303cw
 0ApQxYOXnrIk26MLElTzSMImlSvlzW6/5XXzL9ME16leSHOIfDeerPnc9FU9Eb3z
 ODv22z6tJZ9H/apSUIHZbMciMbbVTZ8zgpkfydr08o87b342N/ncYHZ5cSvQ6DWb
 jS5YOIuvl46/IhMPT16qWC8p0bP5YhxoPv5l6Xr0zq0ooEj0E7keiD/SzoLvW+Qs
 AHXcibguPRQBPAdiPQ==
 =yaaN
 -----END PGP SIGNATURE-----

Merge tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kernel hardening updates from Kees Cook:

 - Convert flexible array members, fix -Wstringop-overflow warnings, and
   fix KCFI function type mismatches that went ignored by maintainers
   (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook)

 - Remove the remaining side-effect users of ksize() by converting
   dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add
   more __alloc_size attributes, and introduce full testing of all
   allocator functions. Finally remove the ksize() side-effect so that
   each allocation-aware checker can finally behave without exceptions

 - Introduce oops_limit (default 10,000) and warn_limit (default off) to
   provide greater granularity of control for panic_on_oops and
   panic_on_warn (Jann Horn, Kees Cook)

 - Introduce overflows_type() and castable_to_type() helpers for cleaner
   overflow checking

 - Improve code generation for strscpy() and update str*() kern-doc

 - Convert strscpy and sigphash tests to KUnit, and expand memcpy tests

 - Always use a non-NULL argument for prepare_kernel_cred()

 - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell)

 - Adjust orphan linker section checking to respect CONFIG_WERROR (Xin
   Li)

 - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu)

 - Fix um vs FORTIFY warnings for always-NULL arguments

* tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits)
  ksmbd: replace one-element arrays with flexible-array members
  hpet: Replace one-element array with flexible-array member
  um: virt-pci: Avoid GCC non-NULL warning
  signal: Initialize the info in ksignal
  lib: fortify_kunit: build without structleak plugin
  panic: Expose "warn_count" to sysfs
  panic: Introduce warn_limit
  panic: Consolidate open-coded panic_on_warn checks
  exit: Allow oops_limit to be disabled
  exit: Expose "oops_count" to sysfs
  exit: Put an upper limit on how often we can oops
  panic: Separate sysctl logic from CONFIG_SMP
  mm/pgtable: Fix multiple -Wstringop-overflow warnings
  mm: Make ksize() a reporting-only function
  kunit/fortify: Validate __alloc_size attribute results
  drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid()
  drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid()
  driver core: Add __alloc_size hint to devm allocators
  overflow: Introduce overflows_type() and castable_to_type()
  coredump: Proactively round up to kmalloc bucket size
  ...
2022-12-14 12:20:00 -08:00
Linus Torvalds
e2ca6ba6ba MM patches for 6.2-rc1.
- More userfaultfs work from Peter Xu.
 
 - Several convert-to-folios series from Sidhartha Kumar and Huang Ying.
 
 - Some filemap cleanups from Vishal Moola.
 
 - David Hildenbrand added the ability to selftest anon memory COW handling.
 
 - Some cpuset simplifications from Liu Shixin.
 
 - Addition of vmalloc tracing support by Uladzislau Rezki.
 
 - Some pagecache folioifications and simplifications from Matthew Wilcox.
 
 - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it.
 
 - Miguel Ojeda contributed some cleanups for our use of the
   __no_sanitize_thread__ gcc keyword.  This series shold have been in the
   non-MM tree, my bad.
 
 - Naoya Horiguchi improved the interaction between memory poisoning and
   memory section removal for huge pages.
 
 - DAMON cleanups and tuneups from SeongJae Park
 
 - Tony Luck fixed the handling of COW faults against poisoned pages.
 
 - Peter Xu utilized the PTE marker code for handling swapin errors.
 
 - Hugh Dickins reworked compound page mapcount handling, simplifying it
   and making it more efficient.
 
 - Removal of the autonuma savedwrite infrastructure from Nadav Amit and
   David Hildenbrand.
 
 - zram support for multiple compression streams from Sergey Senozhatsky.
 
 - David Hildenbrand reworked the GUP code's R/O long-term pinning so
   that drivers no longer need to use the FOLL_FORCE workaround which
   didn't work very well anyway.
 
 - Mel Gorman altered the page allocator so that local IRQs can remnain
   enabled during per-cpu page allocations.
 
 - Vishal Moola removed the try_to_release_page() wrapper.
 
 - Stefan Roesch added some per-BDI sysfs tunables which are used to
   prevent network block devices from dirtying excessive amounts of
   pagecache.
 
 - David Hildenbrand did some cleanup and repair work on KSM COW
   breaking.
 
 - Nhat Pham and Johannes Weiner have implemented writeback in zswap's
   zsmalloc backend.
 
 - Brian Foster has fixed a longstanding corner-case oddity in
   file[map]_write_and_wait_range().
 
 - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang
   Chen.
 
 - Shiyang Ruan has done some work on fsdax, to make its reflink mode
   work better under xfstests.  Better, but still not perfect.
 
 - Christoph Hellwig has removed the .writepage() method from several
   filesystems.  They only need .writepages().
 
 - Yosry Ahmed wrote a series which fixes the memcg reclaim target
   beancounting.
 
 - David Hildenbrand has fixed some of our MM selftests for 32-bit
   machines.
 
 - Many singleton patches, as usual.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY5j6ZwAKCRDdBJ7gKXxA
 jkDYAP9qNeVqp9iuHjZNTqzMXkfmJPsw2kmy2P+VdzYVuQRcJgEAgoV9d7oMq4ml
 CodAgiA51qwzId3GRytIo/tfWZSezgA=
 =d19R
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - More userfaultfs work from Peter Xu

 - Several convert-to-folios series from Sidhartha Kumar and Huang Ying

 - Some filemap cleanups from Vishal Moola

 - David Hildenbrand added the ability to selftest anon memory COW
   handling

 - Some cpuset simplifications from Liu Shixin

 - Addition of vmalloc tracing support by Uladzislau Rezki

 - Some pagecache folioifications and simplifications from Matthew
   Wilcox

 - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use
   it

 - Miguel Ojeda contributed some cleanups for our use of the
   __no_sanitize_thread__ gcc keyword.

   This series should have been in the non-MM tree, my bad

 - Naoya Horiguchi improved the interaction between memory poisoning and
   memory section removal for huge pages

 - DAMON cleanups and tuneups from SeongJae Park

 - Tony Luck fixed the handling of COW faults against poisoned pages

 - Peter Xu utilized the PTE marker code for handling swapin errors

 - Hugh Dickins reworked compound page mapcount handling, simplifying it
   and making it more efficient

 - Removal of the autonuma savedwrite infrastructure from Nadav Amit and
   David Hildenbrand

 - zram support for multiple compression streams from Sergey Senozhatsky

 - David Hildenbrand reworked the GUP code's R/O long-term pinning so
   that drivers no longer need to use the FOLL_FORCE workaround which
   didn't work very well anyway

 - Mel Gorman altered the page allocator so that local IRQs can remnain
   enabled during per-cpu page allocations

 - Vishal Moola removed the try_to_release_page() wrapper

 - Stefan Roesch added some per-BDI sysfs tunables which are used to
   prevent network block devices from dirtying excessive amounts of
   pagecache

 - David Hildenbrand did some cleanup and repair work on KSM COW
   breaking

 - Nhat Pham and Johannes Weiner have implemented writeback in zswap's
   zsmalloc backend

 - Brian Foster has fixed a longstanding corner-case oddity in
   file[map]_write_and_wait_range()

 - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang
   Chen

 - Shiyang Ruan has done some work on fsdax, to make its reflink mode
   work better under xfstests. Better, but still not perfect

 - Christoph Hellwig has removed the .writepage() method from several
   filesystems. They only need .writepages()

 - Yosry Ahmed wrote a series which fixes the memcg reclaim target
   beancounting

 - David Hildenbrand has fixed some of our MM selftests for 32-bit
   machines

 - Many singleton patches, as usual

* tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits)
  mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio
  mm: mmu_gather: allow more than one batch of delayed rmaps
  mm: fix typo in struct pglist_data code comment
  kmsan: fix memcpy tests
  mm: add cond_resched() in swapin_walk_pmd_entry()
  mm: do not show fs mm pc for VM_LOCKONFAULT pages
  selftests/vm: ksm_functional_tests: fixes for 32bit
  selftests/vm: cow: fix compile warning on 32bit
  selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions
  mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem
  mm,thp,rmap: fix races between updates of subpages_mapcount
  mm: memcg: fix swapcached stat accounting
  mm: add nodes= arg to memory.reclaim
  mm: disable top-tier fallback to reclaim on proactive reclaim
  selftests: cgroup: make sure reclaim target memcg is unprotected
  selftests: cgroup: refactor proactive reclaim code to reclaim_until()
  mm: memcg: fix stale protection of reclaim target memcg
  mm/mmap: properly unaccount memory on mas_preallocate() failure
  omfs: remove ->writepage
  jfs: remove ->writepage
  ...
2022-12-13 19:29:45 -08:00
Linus Torvalds
268325bda5 Random number generator updates for Linux 6.2-rc1.
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEq5lC5tSkz8NBJiCnSfxwEqXeA64FAmOU+U8ACgkQSfxwEqXe
 A67NnQ//Y5DltmvibyPd7r1TFT2gUYv+Rx3sUV9ZE1NYptd/SWhhcL8c5FZ70Fuw
 bSKCa1uiWjOxosjXT1kGrWq3de7q7oUpAPSOGxgxzoaNURIt58N/ajItCX/4Au8I
 RlGAScHy5e5t41/26a498kB6qJ441fBEqCYKQpPLINMBAhe8TQ+NVp0rlpUwNHFX
 WrUGg4oKWxdBIW3HkDirQjJWDkkAiklRTifQh/Al4b6QDbOnRUGGCeckNOhixsvS
 waHWTld+Td8jRrA4b82tUb2uVZ2/b8dEvj/A8CuTv4yC0lywoyMgBWmJAGOC+UmT
 ZVNdGW02Jc2T+Iap8ZdsEmeLHNqbli4+IcbY5xNlov+tHJ2oz41H9TZoYKbudlr6
 /ReAUPSn7i50PhbQlEruj3eg+M2gjOeh8OF8UKwwRK8PghvyWQ1ScW0l3kUhPIhI
 PdIG6j4+D2mJc1FIj2rTVB+Bg933x6S+qx4zDxGlNp62AARUFYf6EgyD6aXFQVuX
 RxcKb6cjRuFkzFiKc8zkqg5edZH+IJcPNuIBmABqTGBOxbZWURXzIQvK/iULqZa4
 CdGAFIs6FuOh8pFHLI3R4YoHBopbHup/xKDEeAO9KZGyeVIuOSERDxxo5f/ITzcq
 APvT77DFOEuyvanr8RMqqh0yUjzcddXqw9+ieufsAyDwjD9DTuE=
 =QRhK
 -----END PGP SIGNATURE-----

Merge tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull random number generator updates from Jason Donenfeld:

 - Replace prandom_u32_max() and various open-coded variants of it,
   there is now a new family of functions that uses fast rejection
   sampling to choose properly uniformly random numbers within an
   interval:

       get_random_u32_below(ceil) - [0, ceil)
       get_random_u32_above(floor) - (floor, U32_MAX]
       get_random_u32_inclusive(floor, ceil) - [floor, ceil]

   Coccinelle was used to convert all current users of
   prandom_u32_max(), as well as many open-coded patterns, resulting in
   improvements throughout the tree.

   I'll have a "late" 6.1-rc1 pull for you that removes the now unused
   prandom_u32_max() function, just in case any other trees add a new
   use case of it that needs to converted. According to linux-next,
   there may be two trivial cases of prandom_u32_max() reintroductions
   that are fixable with a 's/.../.../'. So I'll have for you a final
   conversion patch doing that alongside the removal patch during the
   second week.

   This is a treewide change that touches many files throughout.

 - More consistent use of get_random_canary().

 - Updates to comments, documentation, tests, headers, and
   simplification in configuration.

 - The arch_get_random*_early() abstraction was only used by arm64 and
   wasn't entirely useful, so this has been replaced by code that works
   in all relevant contexts.

 - The kernel will use and manage random seeds in non-volatile EFI
   variables, refreshing a variable with a fresh seed when the RNG is
   initialized. The RNG GUID namespace is then hidden from efivarfs to
   prevent accidental leakage.

   These changes are split into random.c infrastructure code used in the
   EFI subsystem, in this pull request, and related support inside of
   EFISTUB, in Ard's EFI tree. These are co-dependent for full
   functionality, but the order of merging doesn't matter.

 - Part of the infrastructure added for the EFI support is also used for
   an improvement to the way vsprintf initializes its siphash key,
   replacing an sleep loop wart.

 - The hardware RNG framework now always calls its correct random.c
   input function, add_hwgenerator_randomness(), rather than sometimes
   going through helpers better suited for other cases.

 - The add_latent_entropy() function has long been called from the fork
   handler, but is a no-op when the latent entropy gcc plugin isn't
   used, which is fine for the purposes of latent entropy.

   But it was missing out on the cycle counter that was also being mixed
   in beside the latent entropy variable. So now, if the latent entropy
   gcc plugin isn't enabled, add_latent_entropy() will expand to a call
   to add_device_randomness(NULL, 0), which adds a cycle counter,
   without the absent latent entropy variable.

 - The RNG is now reseeded from a delayed worker, rather than on demand
   when used. Always running from a worker allows it to make use of the
   CPU RNG on platforms like S390x, whose instructions are too slow to
   do so from interrupts. It also has the effect of adding in new inputs
   more frequently with more regularity, amounting to a long term
   transcript of random values. Plus, it helps a bit with the upcoming
   vDSO implementation (which isn't yet ready for 6.2).

 - The jitter entropy algorithm now tries to execute on many different
   CPUs, round-robining, in hopes of hitting even more memory latencies
   and other unpredictable effects. It also will mix in a cycle counter
   when the entropy timer fires, in addition to being mixed in from the
   main loop, to account more explicitly for fluctuations in that timer
   firing. And the state it touches is now kept within the same cache
   line, so that it's assured that the different execution contexts will
   cause latencies.

* tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits)
  random: include <linux/once.h> in the right header
  random: align entropy_timer_state to cache line
  random: mix in cycle counter when jitter timer fires
  random: spread out jitter callback to different CPUs
  random: remove extraneous period and add a missing one in comments
  efi: random: refresh non-volatile random seed when RNG is initialized
  vsprintf: initialize siphash key using notifier
  random: add back async readiness notifier
  random: reseed in delayed work rather than on-demand
  random: always mix cycle counter in add_latent_entropy()
  hw_random: use add_hwgenerator_randomness() for early entropy
  random: modernize documentation comment on get_random_bytes()
  random: adjust comment to account for removed function
  random: remove early archrandom abstraction
  random: use random.trust_{bootloader,cpu} command line option only
  stackprotector: actually use get_random_canary()
  stackprotector: move get_random_canary() into stackprotector.h
  treewide: use get_random_u32_inclusive() when possible
  treewide: use get_random_u32_{above,below}() instead of manual loop
  treewide: use get_random_u32_below() instead of deprecated function
  ...
2022-12-12 16:22:22 -08:00
Kees Cook
79cc1ba7ba panic: Consolidate open-coded panic_on_warn checks
Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
their own warnings, and each check "panic_on_warn". Consolidate this
into a single function so that future instrumentation can be added in
a single location.

Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Gow <davidgow@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org
2022-12-02 13:04:44 -08:00
Pavankumar Kondeti
c66b6ead74 mm/kfence: remove hung_task cruft
commit fdf756f712 ("sched: Fix more TASK_state comparisons") makes
hung_task not to monitor TASK_IDLE tasks.  The special handling to
workaround hung_task warnings is not required anymore.

Link: https://lkml.kernel.org/r/1667986006-25420-1-git-send-email-quic_pkondeti@quicinc.com
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:53 -08:00
Marco Elver
747c0f35f2 kfence: fix stack trace pruning
Commit b140513524 ("mm/sl[au]b: generalize kmalloc subsystem")
refactored large parts of the kmalloc subsystem, resulting in the stack
trace pruning logic done by KFENCE to no longer work.

While b140513524 attempted to fix the situation by including
'__kmem_cache_free' in the list of functions KFENCE should skip through,
this only works when the compiler actually optimized the tail call from
kfree() to __kmem_cache_free() into a jump (and thus kfree() _not_
appearing in the full stack trace to begin with).

In some configurations, the compiler no longer optimizes the tail call
into a jump, and __kmem_cache_free() appears in the stack trace.  This
means that the pruned stack trace shown by KFENCE would include kfree()
which is not intended - for example:

 | BUG: KFENCE: invalid free in kfree+0x7c/0x120
 |
 | Invalid free of 0xffff8883ed8fefe0 (in kfence-#126):
 |  kfree+0x7c/0x120
 |  test_double_free+0x116/0x1a9
 |  kunit_try_run_case+0x90/0xd0
 | [...]

Fix it by moving __kmem_cache_free() to the list of functions that may be
tail called by an allocator entry function, making the pruning logic work
in both the optimized and unoptimized tail call cases.

Link: https://lkml.kernel.org/r/20221118152216.3914899-1-elver@google.com
Fixes: b140513524 ("mm/sl[au]b: generalize kmalloc subsystem")
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-22 18:50:44 -08:00
Jason A. Donenfeld
e8a533cbeb treewide: use get_random_u32_inclusive() when possible
These cases were done with this Coccinelle:

@@
expression H;
expression L;
@@
- (get_random_u32_below(H) + L)
+ get_random_u32_inclusive(L, H + L - 1)

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_inclusive(L,
  H
- + E
- - E
  )

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_inclusive(L,
  H
- - E
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_inclusive(L,
  H
- - E
  + F
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_inclusive(L,
  H
- + E
  + F
- - E
  )

And then subsequently cleaned up by hand, with several automatic cases
rejected if it didn't make sense contextually.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-11-18 02:18:02 +01:00
Jason A. Donenfeld
8032bf1233 treewide: use get_random_u32_below() instead of deprecated function
This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
  (E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-11-18 02:15:15 +01:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0HaPgAKCRDdBJ7gKXxA
 joPjAQDZ5LlRCMWZ1oxLP2NOTp6nm63q9PWcGnmY50FjD/dNlwEAnx7OejCLWGWf
 bbTuk6U2+TKgJa4X7+pbbejeoqnt5QU=
 =xfWx
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Linus Torvalds
8adc0486f3 Random number generator updates for Linux 6.1-rc1.
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEq5lC5tSkz8NBJiCnSfxwEqXeA64FAmM++NMACgkQSfxwEqXe
 A65f3w//eRwdaZV5eX3m9eb3CsNnnut2dDKNG+HrImd+z+96CbpBCsyZN2p5uDMw
 pPownat8Ejv6P6E0ztOAyCsFDnS0Tf2YjdVOZ9txif5zIwqoM8TYbmHlmm7JhACc
 hDoblbICTf/bmSURWQOCdkayPhqIyV61pF5hwXXQuCAMoanHzDWbH1yxMmBMCQYJ
 P6fA0r2BYniC90o/C0HvToeIw7tTGxBm2Lki/S9cWOFCzPBwQytBbE7AD4rBP8+Y
 ryHdcpKaXLF9C1zSlYfyLBbBGR3Oe+DBLl081q3LkTjnnoPbLEtJE1B644K5FiOJ
 ySkeHZoMeGB2fisoEJAaEf1GjA1I6f1fcmTlY57XbR/iU3gfQE6+06CwVJBUoqtx
 Q71FMU+AMoc1ZfDVQB8NC+RdifV1qRhzVPrawhCPPfx8ngR8yKekh9RYwp0xpGPL
 RoAqswoOwOW20BalNxRipLji1URcZGH1d3QgkjdIwxvodyPsiGg74LJ9xBYWccfv
 jBS6vNEGgWYUtMA/20W0HowSizA89Rl9REBd7M8q+eLOhJ/AsUgzuJ9noODBe6OV
 PO4NDWXwaud64gDHtPhomah/14zej53yomlC/qJ9cJN4uPo6J3u9phqcaOWHjgPX
 AKYRGWxCgnwpf7g6v4S/35kU+OEs9fS+oDKUzUY8s7lhNM4qCK0=
 =KGwF
 -----END PGP SIGNATURE-----

Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull random number generator updates from Jason Donenfeld:

 - Huawei reported that when they updated their kernel from 4.4 to
   something much newer, some userspace code they had broke, the culprit
   being the accidental removal of O_NONBLOCK from /dev/random way back
   in 5.6. It's been gone for over 2 years now and this is the first
   we've heard of it, but userspace breakage is userspace breakage, so
   O_NONBLOCK is now back.

 - Use randomness from hardware RNGs much more often during early boot,
   at the same interval that crng reseeds are done, from Dominik.

 - A semantic change in hardware RNG throttling, so that the hwrng
   framework can properly feed random.c with randomness from hardware
   RNGs that aren't specifically marked as creditable.

   A related patch coming to you via Herbert's hwrng tree depends on
   this one, not to compile, but just to function properly, so you may
   want to merge this PULL before that one.

 - A fix to clamp credited bits from the interrupts pool to the size of
   the pool sample. This is mainly just a theoretical fix, as it'd be
   pretty hard to exceed it in practice.

 - Oracle reported that InfiniBand TCP latency regressed by around
   10-15% after a change a few cycles ago made at the request of the RT
   folks, in which we hoisted a somewhat rare operation (1 in 1024
   times) out of the hard IRQ handler and into a workqueue, a pretty
   common and boring pattern.

   It turns out, though, that scheduling a worker from there has
   overhead of its own, whereas scheduling a timer on that same CPU for
   the next jiffy amortizes better and doesn't incur the same overhead.

   I also eliminated a cache miss by moving the work_struct (and
   subsequently, the timer_list) to below a critical cache line, so that
   the more critical members that are accessed on every hard IRQ aren't
   split between two cache lines.

 - The boot-time initialization of the RNG has been split into two
   approximate phases: what we can accomplish before timekeeping is
   possible and what we can accomplish after.

   This winds up being useful so that we can use RDRAND to seed the RNG
   before CONFIG_SLAB_FREELIST_RANDOM=y systems initialize slabs, in
   addition to other early uses of randomness. The effect is that
   systems with RDRAND (or a bootloader seed) will never see any
   warnings at all when setting CONFIG_WARN_ALL_UNSEEDED_RANDOM=y. And
   kfence benefits from getting a better seed of its own.

 - Small systems without much entropy sometimes wind up putting some
   truncated serial number read from flash into hostname, so contribute
   utsname changes to the RNG, without crediting.

 - Add smaller batches to serve requests for smaller integers, and make
   use of them when people ask for random numbers bounded by a given
   compile-time constant. This has positive effects all over the tree,
   most notably in networking and kfence.

 - The original jitter algorithm intended (I believe) to schedule the
   timer for the next jiffy, not the next-next jiffy, yet it used
   mod_timer(jiffies + 1), which will fire on the next-next jiffy,
   instead of what I believe was intended, mod_timer(jiffies), which
   will fire on the next jiffy. So fix that.

 - Fix a comment typo, from William.

* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  random: clear new batches when bringing new CPUs online
  random: fix typos in get_random_bytes() comment
  random: schedule jitter credit for next jiffy, not in two jiffies
  prandom: make use of smaller types in prandom_u32_max
  random: add 8-bit and 16-bit batches
  utsname: contribute changes to RNG
  random: use init_utsname() instead of utsname()
  kfence: use better stack hash seed
  random: split initialization into early step and later step
  random: use expired timer rather than wq for mixing fast pool
  random: avoid reading two cache lines on irq randomness
  random: clamp credited irq bits to maximum mixed
  random: throttle hwrng writes if no entropy is credited
  random: use hwgenerator randomness more frequently at early boot
  random: restore O_NONBLOCK support
2022-10-10 10:41:21 -07:00
Liu Shixin
6b1964e685 mm: kfence: convert to DEFINE_SEQ_ATTRIBUTE
Use DEFINE_SEQ_ATTRIBUTE helper macro to simplify the code.

Link: https://lkml.kernel.org/r/20220909083140.3592919-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:07 -07:00
Jason A. Donenfeld
08475dab7c kfence: use better stack hash seed
As of the prior commit, the RNG will have incorporated both a cycle
counter value and RDRAND, in addition to various other environmental
noise. Therefore, using get_random_u32() will supply a stronger seed
than simply using random_get_entropy(). N.B.: random_get_entropy()
should be considered an internal API of random.c and not generally
consumed.

Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-09-29 21:37:27 +02:00
Imran Khan
b84e04f1ba kfence: add sysfs interface to disable kfence for selected slabs.
By default kfence allocation can happen for any slab object, whose size is
up to PAGE_SIZE, as long as that allocation is the first allocation after
expiration of kfence sample interval.  But in certain debugging scenarios
we may be interested in debugging corruptions involving some specific slub
objects like dentry or ext4_* etc.  In such cases limiting kfence for
allocations involving only specific slub objects will increase the
probablity of catching the issue since kfence pool will not be consumed by
other slab objects.

This patch introduces a sysfs interface
'/sys/kernel/slab/<name>/skip_kfence' to disable kfence for specific
slabs.  Having the interface work in this way does not impact
current/default behavior of kfence and allows us to use kfence for
specific slabs (when needed) as well.  The decision to skip/use kfence is
taken depending on whether kmem_cache.flags has (newly introduced)
SLAB_SKIP_KFENCE flag set or not.

Link: https://lkml.kernel.org/r/20220814195353.2540848-1-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:52 -07:00
Hyeonggon Yoo
b140513524 mm/sl[au]b: generalize kmalloc subsystem
Now everything in kmalloc subsystem can be generalized.
Let's do it!

Generalize __do_kmalloc_node(), __kmalloc_node_track_caller(),
kfree(), __ksize(), __kmalloc(), __kmalloc_node() and move them
to slab_common.c.

In the meantime, rename kmalloc_large_node_notrace()
to __kmalloc_large_node() and make it static as it's now only called in
slab_common.c.

[ feng.tang@intel.com: adjust kfence skip list to include
  __kmem_cache_free so that kfence kunit tests do not fail ]

Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-09-01 10:38:06 +02:00
Linus Torvalds
6614a3c316 - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
 
 - Some kmemleak fixes from Patrick Wang and Waiman Long
 
 - DAMON updates from SeongJae Park
 
 - memcg debug/visibility work from Roman Gushchin
 
 - vmalloc speedup from Uladzislau Rezki
 
 - more folio conversion work from Matthew Wilcox
 
 - enhancements for coherent device memory mapping from Alex Sierra
 
 - addition of shared pages tracking and CoW support for fsdax, from
   Shiyang Ruan
 
 - hugetlb optimizations from Mike Kravetz
 
 - Mel Gorman has contributed some pagealloc changes to improve latency
   and realtime behaviour.
 
 - mprotect soft-dirty checking has been improved by Peter Xu
 
 - Many other singleton patches all over the place
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCYuravgAKCRDdBJ7gKXxA
 jpqSAQDrXSdII+ht9kSHlaCVYjqRFQz/rRvURQrWQV74f6aeiAD+NHHeDPwZn11/
 SPktqEUrF1pxnGQxqLh1kUFUhsVZQgE=
 =w/UH
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
2022-08-05 16:32:45 -07:00
Yee Lee
07313a2b29 mm: kfence: apply kmemleak_ignore_phys on early allocated pool
This patch solves two issues.

(1) The pool allocated by memblock needs to unregister from
kmemleak scanning. Apply kmemleak_ignore_phys to replace the
original kmemleak_free as its address now is stored in the phys tree.

(2) The pool late allocated by page-alloc doesn't need to unregister.
Move out the freeing operation from its call path.

Link: https://lkml.kernel.org/r/20220628113714.7792-2-yee.lee@mediatek.com
Fixes: 0c24e06119 ("mm: kmemleak: add rbtree and store physical address for objects allocated with PA")
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18 15:07:51 -07:00
Linus Walleij
9e7ee421ac mm: kfence: pass a pointer to virt_to_page()
Functions that work on a pointer to virtual memory such as virt_to_pfn()
and users of that function such as virt_to_page() are supposed to pass a
pointer to virtual memory, ideally a (void *) or other pointer.  However
since many architectures implement virt_to_pfn() as a macro, this function
becomes polymorphic and accepts both a (unsigned long) and a (void *).

If we instead implement a proper virt_to_pfn(void *addr) function the
following happens (occurred on arch/arm):

mm/kfence/core.c:558:30: warning: passing argument 1
  of 'virt_to_pfn' makes pointer from integer without a
  cast [-Wint-conversion]

In one case we can refer to __kfence_pool directly (and that is a proper
(char *) pointer) and in the other call site we use an explicit cast.

Link: https://lkml.kernel.org/r/20220630084124.691207-4-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:36 -07:00
Jason A. Donenfeld
327b18b7aa mm/kfence: select random number before taking raw lock
The RNG uses vanilla spinlocks, not raw spinlocks, so kfence should pick
its random numbers before taking its raw spinlocks.  This also has the
nice effect of doing less work inside the lock.  It should fix a splat
that Geert saw with CONFIG_PROVE_RAW_LOCK_NESTING:

     dump_backtrace.part.0+0x98/0xc0
     show_stack+0x14/0x28
     dump_stack_lvl+0xac/0xec
     dump_stack+0x14/0x2c
     __lock_acquire+0x388/0x10a0
     lock_acquire+0x190/0x2c0
     _raw_spin_lock_irqsave+0x6c/0x94
     crng_make_state+0x148/0x1e4
     _get_random_bytes.part.0+0x4c/0xe8
     get_random_u32+0x4c/0x140
     __kfence_alloc+0x460/0x5c4
     kmem_cache_alloc_trace+0x194/0x1dc
     __kthread_create_on_node+0x5c/0x1a8
     kthread_create_on_node+0x58/0x7c
     printk_start_kthread.part.0+0x34/0xa8
     printk_activate_kthreads+0x4c/0x54
     do_one_initcall+0xec/0x278
     kernel_init_freeable+0x11c/0x214
     kernel_init+0x24/0x124
     ret_from_fork+0x10/0x20

Link: https://lkml.kernel.org/r/20220609123319.17576-1-Jason@zx2c4.com
Fixes: d4150779e6 ("random32: use real rng for non-deterministic randomness")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16 19:11:31 -07:00
Linus Torvalds
98931dd95f Yang Shi has improved the behaviour of khugepaged collapsing of readonly
file-backed transparent hugepages.
 
 Johannes Weiner has arranged for zswap memory use to be tracked and
 managed on a per-cgroup basis.
 
 Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime
 enablement of the recent huge page vmemmap optimization feature.
 
 Baolin Wang contributes a series to fix some issues around hugetlb
 pagetable invalidation.
 
 Zhenwei Pi has fixed some interactions between hwpoisoned pages and
 virtualization.
 
 Tong Tiangen has enabled the use of the presently x86-only
 page_table_check debugging feature on arm64 and riscv.
 
 David Vernet has done some fixup work on the memcg selftests.
 
 Peter Xu has taught userfaultfd to handle write protection faults against
 shmem- and hugetlbfs-backed files.
 
 More DAMON development from SeongJae Park - adding online tuning of the
 feature and support for monitoring of fixed virtual address ranges.  Also
 easier discovery of which monitoring operations are available.
 
 Nadav Amit has done some optimization of TLB flushing during mprotect().
 
 Neil Brown continues to labor away at improving our swap-over-NFS support.
 
 David Hildenbrand has some fixes to anon page COWing versus
 get_user_pages().
 
 Peng Liu fixed some errors in the core hugetlb code.
 
 Joao Martins has reduced the amount of memory consumed by device-dax's
 compound devmaps.
 
 Some cleanups of the arch-specific pagemap code from Anshuman Khandual.
 
 Muchun Song has found and fixed some errors in the TLB flushing of
 transparent hugepages.
 
 Roman Gushchin has done more work on the memcg selftests.
 
 And, of course, many smaller fixes and cleanups.  Notably, the customary
 million cleanup serieses from Miaohe Lin.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCYo52xQAKCRDdBJ7gKXxA
 jtJFAQD238KoeI9z5SkPMaeBRYSRQmNll85mxs25KapcEgWgGQD9FAb7DJkqsIVk
 PzE+d9hEfirUGdL6cujatwJ6ejYR8Q8=
 =nFe6
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Almost all of MM here. A few things are still getting finished off,
  reviewed, etc.

   - Yang Shi has improved the behaviour of khugepaged collapsing of
     readonly file-backed transparent hugepages.

   - Johannes Weiner has arranged for zswap memory use to be tracked and
     managed on a per-cgroup basis.

   - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
     runtime enablement of the recent huge page vmemmap optimization
     feature.

   - Baolin Wang contributes a series to fix some issues around hugetlb
     pagetable invalidation.

   - Zhenwei Pi has fixed some interactions between hwpoisoned pages and
     virtualization.

   - Tong Tiangen has enabled the use of the presently x86-only
     page_table_check debugging feature on arm64 and riscv.

   - David Vernet has done some fixup work on the memcg selftests.

   - Peter Xu has taught userfaultfd to handle write protection faults
     against shmem- and hugetlbfs-backed files.

   - More DAMON development from SeongJae Park - adding online tuning of
     the feature and support for monitoring of fixed virtual address
     ranges. Also easier discovery of which monitoring operations are
     available.

   - Nadav Amit has done some optimization of TLB flushing during
     mprotect().

   - Neil Brown continues to labor away at improving our swap-over-NFS
     support.

   - David Hildenbrand has some fixes to anon page COWing versus
     get_user_pages().

   - Peng Liu fixed some errors in the core hugetlb code.

   - Joao Martins has reduced the amount of memory consumed by
     device-dax's compound devmaps.

   - Some cleanups of the arch-specific pagemap code from Anshuman
     Khandual.

   - Muchun Song has found and fixed some errors in the TLB flushing of
     transparent hugepages.

   - Roman Gushchin has done more work on the memcg selftests.

  ... and, of course, many smaller fixes and cleanups. Notably, the
  customary million cleanup serieses from Miaohe Lin"

* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
  mm: kfence: use PAGE_ALIGNED helper
  selftests: vm: add the "settings" file with timeout variable
  selftests: vm: add "test_hmm.sh" to TEST_FILES
  selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
  selftests: vm: add migration to the .gitignore
  selftests/vm/pkeys: fix typo in comment
  ksm: fix typo in comment
  selftests: vm: add process_mrelease tests
  Revert "mm/vmscan: never demote for memcg reclaim"
  mm/kfence: print disabling or re-enabling message
  include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
  include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
  mm: fix a potential infinite loop in start_isolate_page_range()
  MAINTAINERS: add Muchun as co-maintainer for HugeTLB
  zram: fix Kconfig dependency warning
  mm/shmem: fix shmem folio swapoff hang
  cgroup: fix an error handling path in alloc_pagecache_max_30M()
  mm: damon: use HPAGE_PMD_SIZE
  tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
  nodemask.h: fix compilation error with GCC12
  ...
2022-05-26 12:32:41 -07:00
Linus Torvalds
64e34b50d7 linux-kselftest-kunit-5.19-rc1
This KUnit update for Linux 5.19-rc1 consists of several fixes, cleanups,
 and enhancements to tests and framework:
 
 - introduces _NULL and _NOT_NULL macros to pointer error checks
 
 - reworks kunit_resource allocation policy to fix memory leaks when
   caller doesn't specify free() function to be used when allocating
   memory using kunit_add_resource() and kunit_alloc_resource() funcs.
 
 - adds ability to specify suite-level init and exit functions
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEPZKym/RZuOCGeA/kCwJExA0NQxwFAmKLw4QACgkQCwJExA0N
 Qxz9wRAA3PonJESDAFF2sXTDzQurEXdWoJHqNvO0JCObku8SDODEI7nozXOD0MBC
 ASAXiX3HuNI0yESF27xECqu3xbe8KsYOtCN8vco/sYUroVGmzgAt/atsvrSUv2Oh
 sEQbjrTMwkMUjL5ECvjR2dArd6bQew7PPBkl3HqOpyysL3b/EAMEAY0DmDXrrrwB
 +oNvXGVAR1Tczg4ahcSSwDdZl1C41kREj5f8S/4+kohMdIjCUPWOAYnaWHpVdAOJ
 C+LWkPSJ5IpgjU2urDX2kNfg32UxIJpFI009ovytBmwCbd+GEs24u7gtgtksPM2s
 YypoPEqC40gxkbY99omojtADiDdZlKqlIipCTWYe/CpzgBD+WQ4PVqMGM4ZprP9w
 Hrc6ulVmd8hZ4F9QQ3oN6W9L6pBCgdXtPPCsQtGoUTbw7r79BP67PjJ6Ko+usn3s
 Jy0FR5LvzYBjykoJzKSIaJ8ONaX34DB6w5rB+q5mBGwPKPHWo3eAZVZDPEMVo3Z7
 D9TW5UliGBt2y5YJZbPbSnhdJPMPHSK5ef9hIy0wYjVJFafirdgrQhgbWbVxalRT
 eZz1edcs1sdU7GAzfMA/v+NqAAA3bFIUVr2b+GTc+4zzWhq+cwI2SNikgyhETv/f
 xKq8Xek8EkOIdaa2lu9chTPT4sG7A6991EkRqfc7rL1IptkPiS8=
 =DzVQ
 -----END PGP SIGNATURE-----

Merge tag 'linux-kselftest-kunit-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:
 "Several fixes, cleanups, and enhancements to tests and framework:

   - introduce _NULL and _NOT_NULL macros to pointer error checks

   - rework kunit_resource allocation policy to fix memory leaks when
     caller doesn't specify free() function to be used when allocating
     memory using kunit_add_resource() and kunit_alloc_resource() funcs.

   - add ability to specify suite-level init and exit functions"

* tag 'linux-kselftest-kunit-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (41 commits)
  kunit: tool: Use qemu-system-i386 for i386 runs
  kunit: fix executor OOM error handling logic on non-UML
  kunit: tool: update riscv QEMU config with new serial dependency
  kcsan: test: use new suite_{init,exit} support
  kunit: tool: Add list of all valid test configs on UML
  kunit: take `kunit_assert` as `const`
  kunit: tool: misc cleanups
  kunit: tool: minor cosmetic cleanups in kunit_parser.py
  kunit: tool: make parser stop overwriting status of suites w/ no_tests
  kunit: tool: remove dead parse_crash_in_log() logic
  kunit: tool: print clearer error message when there's no TAP output
  kunit: tool: stop using a shell to run kernel under QEMU
  kunit: tool: update test counts summary line format
  kunit: bail out of test filtering logic quicker if OOM
  lib/Kconfig.debug: change KUnit tests to default to KUNIT_ALL_TESTS
  kunit: Rework kunit_resource allocation policy
  kunit: fix debugfs code to use enum kunit_status, not bool
  kfence: test: use new suite_{init/exit} support, add .kunitconfig
  kunit: add ability to specify suite-level init and exit functions
  kunit: rename print_subtest_{start,end} for clarity (s/subtest/suite)
  ...
2022-05-25 11:32:53 -07:00
Kefeng Wang
f403f22f8c mm: kfence: use PAGE_ALIGNED helper
Use PAGE_ALIGNED macro instead of IS_ALIGNED and passing PAGE_SIZE.

Link: https://lkml.kernel.org/r/20220520021833.121405-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-25 10:47:49 -07:00
Jackie Liu
83d7d04f9d mm/kfence: print disabling or re-enabling message
By printing information, we can friendly prompt the status change
information of kfence by dmesg and record by syslog.

Also, set kfence_enabled to false only when needed.

Link: https://lkml.kernel.org/r/20220518073105.3160335-1-liu.yun@linux.dev
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Co-developed-by: Marco Elver <elver@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-25 10:47:48 -07:00
huangshaobo
3c81b3bb0a kfence: enable check kfence canary on panic via boot param
Out-of-bounds accesses that aren't caught by a guard page will result in
corruption of canary memory.  In pathological cases, where an object has
certain alignment requirements, an out-of-bounds access might never be
caught by the guard page.  Such corruptions, however, are only detected on
kfree() normally.  If the bug causes the kernel to panic before kfree(),
KFENCE has no opportunity to report the issue.  Such corruptions may also
indicate failing memory or other faults.

To provide some more information in such cases, add the option to check
canary bytes on panic.  This might help narrow the search for the panic
cause; but, due to only having the allocation stack trace, such reports
are difficult to use to diagnose an issue alone.  In most cases, such
reports are inactionable, and is therefore an opt-in feature (disabled by
default).

[akpm@linux-foundation.org: add __read_mostly, per Marco]
Link: https://lkml.kernel.org/r/20220425022456.44300-1-huangshaobo6@huawei.com
Signed-off-by: huangshaobo <huangshaobo6@huawei.com>
Suggested-by: chenzefeng <chenzefeng2@huawei.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Cc: Wangbing <wangbing6@huawei.com>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13 07:20:06 -07:00
Hyeonggon Yoo
2839b0999c mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool
When kfence fails to initialize kfence pool, it frees the pool.  But it
does not reset memcg_data and PG_slab flag.

Below is a BUG because of this. Let's fix it by resetting memcg_data
and PG_slab flag before free.

[    0.089149] BUG: Bad page state in process swapper/0  pfn:3d8e06
[    0.089149] page:ffffea46cf638180 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3d8e06
[    0.089150] memcg:ffffffff94a475d1
[    0.089150] flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff)
[    0.089151] raw: 0017ffffc0000200 ffffea46cf638188 ffffea46cf638188 0000000000000000
[    0.089152] raw: 0000000000000000 0000000000000000 00000000ffffffff ffffffff94a475d1
[    0.089152] page dumped because: page still charged to cgroup
[    0.089153] Modules linked in:
[    0.089153] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G    B   W         5.18.0-rc1+ #965
[    0.089154] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[    0.089154] Call Trace:
[    0.089155]  <TASK>
[    0.089155]  dump_stack_lvl+0x49/0x5f
[    0.089157]  dump_stack+0x10/0x12
[    0.089158]  bad_page.cold+0x63/0x94
[    0.089159]  check_free_page_bad+0x66/0x70
[    0.089160]  __free_pages_ok+0x423/0x530
[    0.089161]  __free_pages_core+0x8e/0xa0
[    0.089162]  memblock_free_pages+0x10/0x12
[    0.089164]  memblock_free_late+0x8f/0xb9
[    0.089165]  kfence_init+0x68/0x92
[    0.089166]  start_kernel+0x789/0x992
[    0.089167]  x86_64_start_reservations+0x24/0x26
[    0.089168]  x86_64_start_kernel+0xa9/0xaf
[    0.089170]  secondary_startup_64_no_verify+0xd5/0xdb
[    0.089171]  </TASK>

Link: https://lkml.kernel.org/r/YnPG3pQrqfcgOlVa@hyeyoo
Fixes: 0ce20dd840 ("mm: add Kernel Electric-Fence infrastructure")
Fixes: 8f0b364973 ("mm: kfence: fix objcgs vector allocation")
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 17:34:29 -07:00
Daniel Latypov
3b91f82658 kfence: test: use new suite_{init/exit} support, add .kunitconfig
Currently, the kfence test suite could not run via "normal" means since
KUnit didn't support per-suite setup/teardown. So it manually called
internal kunit functions to run itself.
This has some downsides, like missing TAP headers => can't use kunit.py
to run or even parse the test results (w/o tweaks).

Use the newly added support and convert it over, adding a .kunitconfig
so it's even easier to run from kunit.py.

People can now run the test via
$ ./tools/testing/kunit/kunit.py run --kunitconfig=mm/kfence --arch=x86_64
...
[11:02:32] Testing complete. Passed: 23, Failed: 0, Crashed: 0, Skipped: 2, Errors: 0
[11:02:32] Elapsed time: 43.562s total, 0.003s configuring, 9.268s building, 34.281s running

Cc: kasan-dev@googlegroups.com
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2022-05-02 12:35:57 -06:00
Marco Elver
2dfe63e61c mm, kfence: support kmem_dump_obj() for KFENCE objects
Calling kmem_obj_info() via kmem_dump_obj() on KFENCE objects has been
producing garbage data due to the object not actually being maintained
by SLAB or SLUB.

Fix this by implementing __kfence_obj_info() that copies relevant
information to struct kmem_obj_info when the object was allocated by
KFENCE; this is called by a common kmem_obj_info(), which also calls the
slab/slub/slob specific variant now called __kmem_obj_info().

For completeness, kmem_dump_obj() now displays if the object was
allocated by KFENCE.

Link: https://lore.kernel.org/all/20220323090520.GG16885@xsang-OptiPlex-9020/
Link: https://lkml.kernel.org/r/20220406131558.3558585-1-elver@google.com
Fixes: b89fb5ef0c ("mm, kfence: insert KFENCE hooks for SLUB")
Fixes: d3fb45f370 ("mm, kfence: insert KFENCE hooks for SLAB")
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>	[slab]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-15 14:49:55 -07:00
Muchun Song
8f0b364973 mm: kfence: fix objcgs vector allocation
If the kfence object is allocated to be used for objects vector, then
this slot of the pool eventually being occupied permanently since the
vector is never freed.  The solutions could be (1) freeing vector when
the kfence object is freed or (2) allocating all vectors statically.

Since the memory consumption of object vectors is low, it is better to
chose (2) to fix the issue and it is also can reduce overhead of vectors
allocating in the future.

Link: https://lkml.kernel.org/r/20220328132843.16624-1-songmuchun@bytedance.com
Fixes: d3fb45f370 ("mm, kfence: insert KFENCE hooks for SLAB")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-01 11:46:09 -07:00
Marco Elver
737b6a10ac kfence: allow use of a deferrable timer
Allow the use of a deferrable timer, which does not force CPU wake-ups
when the system is idle.  A consequence is that the sample interval
becomes very unpredictable, to the point that it is not guaranteed that
the KFENCE KUnit test still passes.

Nevertheless, on power-constrained systems this may be preferable, so
let's give the user the option should they accept the above trade-off.

Link: https://lkml.kernel.org/r/20220308141415.3168078-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:11 -07:00
Peng Liu
3cb1c9620e kfence: test: try to avoid test_gfpzero trigger rcu_stall
When CONFIG_KFENCE_NUM_OBJECTS is set to a big number, kfence
kunit-test-case test_gfpzero will eat up nearly all the CPU's resources
and rcu_stall is reported as the following log which is cut from a
physical server.

  rcu: INFO: rcu_sched self-detected stall on CPU
  rcu: 	68-....: (14422 ticks this GP) idle=6ce/1/0x4000000000000002
  softirq=592/592 fqs=7500 (t=15004 jiffies g=10677 q=20019)
  Task dump for CPU 68:
  task:kunit_try_catch state:R  running task
  stack:    0 pid: 9728 ppid:     2 flags:0x0000020a
  Call trace:
   dump_backtrace+0x0/0x1e4
   show_stack+0x20/0x2c
   sched_show_task+0x148/0x170
   ...
   rcu_sched_clock_irq+0x70/0x180
   update_process_times+0x68/0xb0
   tick_sched_handle+0x38/0x74
   ...
   gic_handle_irq+0x78/0x2c0
   el1_irq+0xb8/0x140
   kfree+0xd8/0x53c
   test_alloc+0x264/0x310 [kfence_test]
   test_gfpzero+0xf4/0x840 [kfence_test]
   kunit_try_run_case+0x48/0x20c
   kunit_generic_run_threadfn_adapter+0x28/0x34
   kthread+0x108/0x13c
   ret_from_fork+0x10/0x18

To avoid rcu_stall and unacceptable latency, a schedule point is
added to test_gfpzero.

Link: https://lkml.kernel.org/r/20220309083753.1561921-4-liupeng256@huawei.com
Signed-off-by: Peng Liu <liupeng256@huawei.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Wang Kefeng <wangkefeng.wang@huawei.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:11 -07:00
Peng Liu
adf5054570 kunit: fix UAF when run kfence test case test_gfpzero
Patch series "kunit: fix a UAF bug and do some optimization", v2.

This series is to fix UAF (use after free) when running kfence test case
test_gfpzero, which is time costly.  This UAF bug can be easily triggered
by setting CONFIG_KFENCE_NUM_OBJECTS = 65535.  Furthermore, some
optimization for kunit tests has been done.

This patch (of 3):

Kunit will create a new thread to run an actual test case, and the main
process will wait for the completion of the actual test thread until
overtime.  The variable "struct kunit test" has local property in function
kunit_try_catch_run, and will be used in the test case thread.  Task
kunit_try_catch_run will free "struct kunit test" when kunit runs
overtime, but the actual test case is still run and an UAF bug will be
triggered.

The above problem has been both observed in a physical machine and qemu
platform when running kfence kunit tests.  The problem can be triggered
when setting CONFIG_KFENCE_NUM_OBJECTS = 65535.  Under this setting, the
test case test_gfpzero will cost hours and kunit will run to overtime.
The follows show the panic log.

  BUG: unable to handle page fault for address: ffffffff82d882e9

  Call Trace:
   kunit_log_append+0x58/0xd0
   ...
   test_alloc.constprop.0.cold+0x6b/0x8a [kfence_test]
   test_gfpzero.cold+0x61/0x8ab [kfence_test]
   kunit_try_run_case+0x4c/0x70
   kunit_generic_run_threadfn_adapter+0x11/0x20
   kthread+0x166/0x190
   ret_from_fork+0x22/0x30
  Kernel panic - not syncing: Fatal exception
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  Ubuntu-1.8.2-1ubuntu1 04/01/2014

To solve this problem, the test case thread should be stopped when the
kunit frame runs overtime.  The stop signal will send in function
kunit_try_catch_run, and test_gfpzero will handle it.

Link: https://lkml.kernel.org/r/20220309083753.1561921-1-liupeng256@huawei.com
Link: https://lkml.kernel.org/r/20220309083753.1561921-2-liupeng256@huawei.com
Signed-off-by: Peng Liu <liupeng256@huawei.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Wang Kefeng <wangkefeng.wang@huawei.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:11 -07:00
Tianchen Ding
b33f778bba kfence: alloc kfence_pool after system startup
Allow enabling KFENCE after system startup by allocating its pool via the
page allocator. This provides the flexibility to enable KFENCE even if it
wasn't enabled at boot time.

Link: https://lkml.kernel.org/r/20220307074516.6920-3-dtcccc@linux.alibaba.com
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Peng Liu <liupeng256@huawei.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:11 -07:00
Tianchen Ding
698361bca2 kfence: allow re-enabling KFENCE after system startup
Patch series "provide the flexibility to enable KFENCE", v3.

If CONFIG_CONTIG_ALLOC is not supported, we fallback to try
alloc_pages_exact().  Allocating pages in this way has limits about
MAX_ORDER (default 11).  So we will not support allocating kfence pool
after system startup with a large KFENCE_NUM_OBJECTS.

When handling failures in kfence_init_pool_late(), we pair
free_pages_exact() to alloc_pages_exact() for compatibility consideration,
though it actually does the same as free_contig_range().

This patch (of 2):

If once KFENCE is disabled by:
echo 0 > /sys/module/kfence/parameters/sample_interval
KFENCE could never be re-enabled until next rebooting.

Allow re-enabling it by writing a positive num to sample_interval.

Link: https://lkml.kernel.org/r/20220307074516.6920-1-dtcccc@linux.alibaba.com
Link: https://lkml.kernel.org/r/20220307074516.6920-2-dtcccc@linux.alibaba.com
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:11 -07:00