linux.git/include/linux/compiler_types.h, branch v6.1

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

2022-10-11T00:53:04+00:00

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
...

Merge tag 'slab-for-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

2022-10-10T17:21:22+00:00

Pull slab fixes from Vlastimil Babka:

 - The "common kmalloc v4" series [1] by Hyeonggon Yoo.

   While the plan after LPC is to try again if it's possible to get rid
   of SLOB and SLAB (and if any critical aspect of those is not possible
   to achieve with SLUB today, modify it accordingly), it will take a
   while even in case there are no objections.

   Meanwhile this is a nice cleanup and some parts (e.g. to the
   tracepoints) will be useful even if we end up with a single slab
   implementation in the future:

      - Improves the mm/slab_common.c wrappers to allow deleting
        duplicated code between SLAB and SLUB.

      - Large kmalloc() allocations in SLAB are passed to page allocator
        like in SLUB, reducing number of kmalloc caches.

      - Removes the {kmem_cache_alloc,kmalloc}_node variants of
        tracepoints, node id parameter added to non-_node variants.

 - Addition of kmalloc_size_roundup()

   The first two patches from a series by Kees Cook [2] that introduce
   kmalloc_size_roundup(). This will allow merging of per-subsystem
   patches using the new function and ultimately stop (ab)using ksize()
   in a way that causes ongoing trouble for debugging functionality and
   static checkers.

 - Wasted kmalloc() memory tracking in debugfs alloc_traces

   A patch from Feng Tang that enhances the existing debugfs
   alloc_traces file for kmalloc caches with information about how much
   space is wasted by allocations that needs less space than the
   particular kmalloc cache provides.

 - My series [3] to fix validation races for caches with enabled
   debugging:

      - By decoupling the debug cache operation more from non-debug
        fastpaths, extra locking simplifications were possible and thus
        done afterwards.

      - Additional cleanup of PREEMPT_RT specific code on top, by Thomas
        Gleixner.

      - A late fix for slab page leaks caused by the series, by Feng
        Tang.

 - Smaller fixes and cleanups:

      - Unneeded variable removals, by ye xingchen

      - A cleanup removing a BUG_ON() in create_unique_id(), by Chao Yu

Link: https://lore.kernel.org/all/20220817101826.236819-1-42.hyeyoo@gmail.com/ [1]
Link: https://lore.kernel.org/all/20220923202822.2667581-1-keescook@chromium.org/ [2]
Link: https://lore.kernel.org/all/20220823170400.26546-1-vbabka@suse.cz/ [3]

* tag 'slab-for-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (30 commits)
  mm/slub: fix a slab missed to be freed problem
  slab: Introduce kmalloc_size_roundup()
  slab: Remove __malloc attribute from realloc functions
  mm/slub: clean up create_unique_id()
  mm/slub: enable debugging memory wasting of kmalloc
  slub: Make PREEMPT_RT support less convoluted
  mm/slub: simplify __cmpxchg_double_slab() and slab_[un]lock()
  mm/slub: convert object_map_lock to non-raw spinlock
  mm/slub: remove slab_lock() usage for debug operations
  mm/slub: restrict sysfs validation to debug caches and make it safe
  mm/sl[au]b: check if large object is valid in __ksize()
  mm/slab_common: move declaration of __ksize() to mm/slab.h
  mm/slab_common: drop kmem_alloc & avoid dereferencing fields when not using
  mm/slab_common: unify NUMA and UMA version of tracepoints
  mm/sl[au]b: cleanup kmem_cache_alloc[_node]_trace()
  mm/sl[au]b: generalize kmalloc subsystem
  mm/slub: move free_debug_processing() further
  mm/sl[au]b: introduce common alloc/free functions without tracepoint
  mm/slab: kmalloc: pass requests larger than order-1 page to page allocator
  mm/slab_common: cleanup kmalloc_large()
  ...

Merge tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2022-10-04T00:11:07+00:00

Pull kcfi updates from Kees Cook:
 "This replaces the prior support for Clang's standard Control Flow
  Integrity (CFI) instrumentation, which has required a lot of special
  conditions (e.g. LTO) and work-arounds.

  The new implementation ("Kernel CFI") is specific to C, directly
  designed for the Linux kernel, and takes advantage of architectural
  features like x86's IBT. This series retains arm64 support and adds
  x86 support.

  GCC support is expected in the future[1], and additional "generic"
  architectural support is expected soon[2].

  Summary:

   - treewide: Remove old CFI support details

   - arm64: Replace Clang CFI support with Clang KCFI support

   - x86: Introduce Clang KCFI support"

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107048 [1]
Link: https://github.com/samitolvanen/llvm-project/commits/kcfi_generic [2]

* tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits)
  x86: Add support for CONFIG_CFI_CLANG
  x86/purgatory: Disable CFI
  x86: Add types to indirectly called assembly functions
  x86/tools/relocs: Ignore __kcfi_typeid_ relocations
  kallsyms: Drop CONFIG_CFI_CLANG workarounds
  objtool: Disable CFI warnings
  objtool: Preserve special st_shndx indexes in elf_update_symbol
  treewide: Drop __cficanonical
  treewide: Drop WARN_ON_FUNCTION_MISMATCH
  treewide: Drop function_nocfi
  init: Drop __nocfi from __init
  arm64: Drop unneeded __nocfi attributes
  arm64: Add CFI error handling
  arm64: Add types to indirect called assembly functions
  psci: Fix the function type for psci_initcall_t
  lkdtm: Emit an indirect call for CFI tests
  cfi: Add type helper macros
  cfi: Switch to -fsanitize=kcfi
  cfi: Drop __CFI_ADDRESSABLE
  cfi: Remove CONFIG_CFI_CLANG_SHADOW
  ...

kmsan: mark noinstr as __no_sanitize_memory

2022-10-03T21:03:19+00:00

noinstr functions should never be instrumented, so make KMSAN skip them by
applying the __no_sanitize_memory attribute.

Link: https://lkml.kernel.org/r/20220915150417.722975-9-glider@google.com
Signed-off-by: Alexander Potapenko 
Reviewed-by: Marco Elver 
Cc: Alexander Viro 
Cc: Alexei Starovoitov 
Cc: Andrey Konovalov 
Cc: Andrey Konovalov 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Christoph Hellwig 
Cc: Christoph Lameter 
Cc: David Rientjes 
Cc: Dmitry Vyukov 
Cc: Eric Biggers 
Cc: Eric Biggers 
Cc: Eric Dumazet 
Cc: Greg Kroah-Hartman 
Cc: Herbert Xu 
Cc: Ilya Leoshkevich 
Cc: Ingo Molnar 
Cc: Jens Axboe 
Cc: Joonsoo Kim 
Cc: Kees Cook 
Cc: Mark Rutland 
Cc: Matthew Wilcox 
Cc: Michael S. Tsirkin 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: Petr Mladek 
Cc: Stephen Rothwell 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: Vasily Gorbik 
Cc: Vegard Nossum 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

slab: Remove __malloc attribute from realloc functions

2022-09-29T09:05:57+00:00

The __malloc attribute should not be applied to "realloc" functions, as
the returned pointer may alias the storage of the prior pointer. Instead
of splitting __malloc from __alloc_size, which would be a huge amount of
churn, just create __realloc_size for the few cases where it is needed.

Thanks to Geert Uytterhoeven  for reporting build
failures with gcc-8 in earlier version which tried to remove the #ifdef.
While the "alloc_size" attribute is available on all GCC versions, I
forgot that it gets disabled explicitly by the kernel in GCC < 9.1 due
to misbehaviors. Add a note to the compiler_attributes.h entry for it.

Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Cc: Andrew Morton 
Cc: Vlastimil Babka 
Cc: Roman Gushchin 
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Marco Elver 
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook 
Signed-off-by: Vlastimil Babka

Kbuild: add Rust support

2022-09-28T07:02:20+00:00

Having most of the new files in place, we now enable Rust support
in the build system, including `Kconfig` entries related to Rust,
the Rust configuration printer and a few other bits.

Reviewed-by: Kees Cook 
Reviewed-by: Nick Desaulniers 
Tested-by: Nick Desaulniers 
Reviewed-by: Greg Kroah-Hartman 
Co-developed-by: Alex Gaynor 
Signed-off-by: Alex Gaynor 
Co-developed-by: Finn Behrens 
Signed-off-by: Finn Behrens 
Co-developed-by: Adam Bratschi-Kaye 
Signed-off-by: Adam Bratschi-Kaye 
Co-developed-by: Wedson Almeida Filho 
Signed-off-by: Wedson Almeida Filho 
Co-developed-by: Michael Ellerman 
Signed-off-by: Michael Ellerman 
Co-developed-by: Sven Van Asbroeck 
Signed-off-by: Sven Van Asbroeck 
Co-developed-by: Gary Guo 
Signed-off-by: Gary Guo 
Co-developed-by: Boris-Chengbiao Zhou 
Signed-off-by: Boris-Chengbiao Zhou 
Co-developed-by: Boqun Feng 
Signed-off-by: Boqun Feng 
Co-developed-by: Douglas Su 
Signed-off-by: Douglas Su 
Co-developed-by: Dariusz Sosnowski 
Signed-off-by: Dariusz Sosnowski 
Co-developed-by: Antonio Terceiro 
Signed-off-by: Antonio Terceiro 
Co-developed-by: Daniel Xu 
Signed-off-by: Daniel Xu 
Co-developed-by: Björn Roy Baron 
Signed-off-by: Björn Roy Baron 
Co-developed-by: Martin Rodriguez Reboredo 
Signed-off-by: Martin Rodriguez Reboredo 
Signed-off-by: Miguel Ojeda

treewide: Drop __cficanonical

2022-09-26T17:13:15+00:00

CONFIG_CFI_CLANG doesn't use a jump table anymore and therefore,
won't change function references to point elsewhere. Remove the
__cficanonical attribute and all uses of it.

Note that the Clang definition of the attribute was removed earlier,
just clean up the no-op definition and users.

Signed-off-by: Sami Tolvanen 
Reviewed-by: Kees Cook 
Tested-by: Kees Cook 
Tested-by: Nathan Chancellor 
Acked-by: Peter Zijlstra (Intel) 
Tested-by: Peter Zijlstra (Intel) 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20220908215504.3686827-16-samitolvanen@google.com

sparse: introduce conditional lock acquire function attribute

2022-07-03T18:32:22+00:00

The kernel tends to try to avoid conditional locking semantics because
it makes it harder to think about and statically check locking rules,
but we do have a few fundamental locking primitives that take locks
conditionally - most obviously the 'trylock' functions.

That has always been a problem for 'sparse' checking for locking
imbalance, and we've had a special '__cond_lock()' macro that we've used
to let sparse know how the locking works:

    # define __cond_lock(x,c)        ((c) ? ({ __acquire(x); 1; }) : 0)

so that you can then use this to tell sparse that (for example) the
spinlock trylock macro ends up acquiring the lock when it succeeds, but
not when it fails:

    #define raw_spin_trylock(lock)  __cond_lock(lock, _raw_spin_trylock(lock))

and then sparse can follow along the locking rules when you have code like

        if (!spin_trylock(&dentry->d_lock))
                return LRU_SKIP;
	.. sparse sees that the lock is held here..
        spin_unlock(&dentry->d_lock);

and sparse ends up happy about the lock contexts.

However, this '__cond_lock()' use does result in very ugly header files,
and requires you to basically wrap the real function with that macro
that uses '__cond_lock'.  Which has made PeterZ NAK things that try to
fix sparse warnings over the years [1].

To solve this, there is now a very experimental patch to sparse that
basically does the exact same thing as '__cond_lock()' did, but using a
function attribute instead.  That seems to make PeterZ happy [2].

Note that this does not replace existing use of '__cond_lock()', but
only exposes the new proposed attribute and uses it for the previously
unannotated 'refcount_dec_and_lock()' family of functions.

For existing sparse installations, this will make no difference (a
negative output context was ignored), but if you have the experimental
sparse patch it will make sparse now understand code that uses those
functions, the same way '__cond_lock()' makes sparse understand the very
similar 'atomic_dec_and_lock()' uses that have the old '__cond_lock()'
annotations.

Note that in some cases this will silence existing context imbalance
warnings.  But in other cases it may end up exposing new sparse warnings
for code that sparse just didn't see the locking for at all before.

This is a trial, in other words.  I'd expect that if it ends up being
successful, and new sparse releases end up having this new attribute,
we'll migrate the old-style '__cond_lock()' users to use the new-style
'__cond_acquires' function attribute.

The actual experimental sparse patch was posted in [3].

Link: https://lore.kernel.org/all/20130930134434.GC12926@twins.programming.kicks-ass.net/ [1]
Link: https://lore.kernel.org/all/Yr60tWxN4P568x3W@worktop.programming.kicks-ass.net/ [2]
Link: https://lore.kernel.org/all/CAHk-=wjZfO9hGqJ2_hGQG3U_XzSh9_XaXze=HgPdvJbgrvASfA@mail.gmail.com/ [3]
Acked-by: Peter Zijlstra 
Cc: Alexander Aring 
Cc: Luc Van Oostenryck 
Signed-off-by: Linus Torvalds

randstruct: Reorganize Kconfigs and attribute macros

2022-05-08T08:33:06+00:00

In preparation for Clang supporting randstruct, reorganize the Kconfigs,
move the attribute macros, and generalize the feature to be named
CONFIG_RANDSTRUCT for on/off, CONFIG_RANDSTRUCT_FULL for the full
randomization mode, and CONFIG_RANDSTRUCT_PERFORMANCE for the cache-line
sized mode.

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20220503205503.3054173-4-keescook@chromium.org

Merge branch 'akpm' (patches from Andrew)

2022-03-24T21:14:07+00:00

Merge more updates from Andrew Morton:
 "Various misc subsystems, before getting into the post-linux-next
  material.

  41 patches.

  Subsystems affected by this patch series: procfs, misc, core-kernel,
  lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump,
  taskstats, panic, kcov, resource, and ubsan"

* emailed patches from Andrew Morton : (41 commits)
  Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"
  kernel/resource: fix kfree() of bootmem memory again
  kcov: properly handle subsequent mmap calls
  kcov: split ioctl handling into locked and unlocked parts
  panic: move panic_print before kmsg dumpers
  panic: add option to dump all CPUs backtraces in panic_print
  docs: sysctl/kernel: add missing bit to panic_print
  taskstats: remove unneeded dead assignment
  kasan: no need to unset panic_on_warn in end_report()
  ubsan: no need to unset panic_on_warn in ubsan_epilogue()
  panic: unset panic_on_warn inside panic()
  docs: kdump: add scp example to write out the dump file
  docs: kdump: update description about sysfs file system support
  arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible
  cgroup: use irqsave in cgroup_rstat_flush_locked().
  fat: use pointer to simple type in put_user()
  minix: fix bug when opening a file with O_DIRECT
  ...