Commit a2225d931f75 ("autofs: remove left-over autofs4 stubs")
promised the removal of the fs/autofs/Kconfig fragment for AUTOFS4_FS
within a couple of releases, but five years later this still has not
happened yet, and AUTOFS4_FS is still enabled in 63 defconfigs.

Get rid of it mechanically:

   git grep -l CONFIG_AUTOFS4_FS -- '*defconfig' |
       xargs sed -i 's/AUTOFS4_FS/AUTOFS_FS/'

Also just remove the AUTOFS4_FS config option stub.  Anybody who hasn't
regenerated their config file in the last five years will need to just
get the new name right when they do.

Signed-off-by: Sven Joachim <svenjoac@gmx.de>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 9b0da3f22307af693be80f5d3a89dc4c7f360a85.

The sigio.c is clearly user space code which is handled by
arch/um/scripts/Makefile.rules (see USER_OBJS rule).

The above mentioned commit simply broke this agreement,
we may not use Linux kernel internal headers in them without
thorough thinking.

Hence, revert the wrong commit.

Link: https://lkml.kernel.org/r/20230724143131.30090-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307212304.cH79zJp1-lkp@intel.com/
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Herve Codina <herve.codina@bootlin.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Richard Weinberger <richard@nod.at>
Cc: Yang Guang <yang.guang5@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The current name doesn't reflect what it does very well.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lkml.kernel.org/r/20230622144321.427441595%40infradead.org

Pull Kbuild updates from Masahiro Yamada:

 - Remove the deprecated rule to build *.dtbo from *.dts

 - Refactor section mismatch detection in modpost

 - Fix bogus ARM section mismatch detections

 - Fix error of 'make gtags' with O= option

 - Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error
   with the latest LLVM version

 - Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed

 - Ignore more compiler-generated symbols for kallsyms

 - Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles

 - Enable more kernel-doc warnings with W=2

 - Refactor <linux/export.h> by generating KSYMTAB data by modpost

 - Deprecate <asm/export.h> and <asm-generic/export.h>

 - Remove the EXPORT_DATA_SYMBOL macro

 - Move the check for static EXPORT_SYMBOL back to modpost, which makes
   the build faster

 - Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm

 - Warn missing MODULE_DESCRIPTION when building modules with W=1

 - Make 'make clean' robust against too long argument error

 - Exclude more objects from GCOV to fix CFI failures with GCOV

 - Allow 'make modules_install' to install modules.builtin and
   modules.builtin.modinfo even when CONFIG_MODULES is disabled

 - Include modules.builtin and modules.builtin.modinfo in the
   linux-image Debian package even when CONFIG_MODULES is disabled

 - Revive "Entering directory" logging for the latest Make version

* tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits)
  modpost: define more R_ARM_* for old distributions
  kbuild: revive "Entering directory" for Make >= 4.4.1
  kbuild: set correct abs_srctree and abs_objtree for package builds
  scripts/mksysmap: Ignore prefixed KCFI symbols
  kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb
  kbuild: builddeb: always make modules_install, to install modules.builtin*
  modpost: continue even with unknown relocation type
  modpost: factor out Elf_Sym pointer calculation to section_rel()
  modpost: factor out inst location calculation to section_rel()
  kbuild: Disable GCOV for *.mod.o
  kbuild: Fix CFI failures with GCOV
  kbuild: make clean rule robust against too long argument error
  script: modpost: emit a warning when the description is missing
  kbuild: make modules_install copy modules.builtin(.modinfo)
  linux/export.h: rename 'sec' argument to 'license'
  modpost: show offset from symbol for section mismatch warnings
  modpost: merge two similar section mismatch warnings
  kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion
  modpost: use null string instead of NULL pointer for default namespace
  modpost: squash sym_update_namespace() into sym_add_exported()
  ...

Pull slab updates from Vlastimil Babka:

 - SLAB deprecation:

   Following the discussion at LSF/MM 2023 [1] and no objections, the
   SLAB allocator is deprecated by renaming the config option (to make
   its users notice) to CONFIG_SLAB_DEPRECATED with updated help text.
   SLUB should be used instead. Existing defconfigs with CONFIG_SLAB are
   also updated.

 - SLAB_NO_MERGE kmem_cache flag (Jesper Dangaard Brouer):

   There are (very limited) cases where kmem_cache merging is
   undesirable, and existing ways to prevent it are hacky. Introduce a
   new flag to do that cleanly and convert the existing hacky users.
   Btrfs plans to use this for debug kernel builds (that use case is
   always fine), networking for performance reasons (that should be very
   rare).

 - Replace the usage of weak PRNGs (David Keisar Schmidt):

   In addition to using stronger RNGs for the security related features,
   the code is a bit cleaner.

 - Misc code cleanups (SeongJae Parki, Xiongwei Song, Zhen Lei, and
   zhaoxinchao)

Link: https://lwn.net/Articles/932201/ [1]

* tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab_common: use SLAB_NO_MERGE instead of negative refcount
  mm/slab: break up RCU readers on SLAB_TYPESAFE_BY_RCU example code
  mm/slab: add a missing semicolon on SLAB_TYPESAFE_BY_RCU example code
  mm/slab_common: reduce an if statement in create_cache()
  mm/slab: introduce kmem_cache flag SLAB_NO_MERGE
  mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED
  mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR
  mm/slab_common: Replace invocation of weak PRNG
  mm/slab: Replace invocation of weak PRNG
  slub: Don't read nr_slabs and total_objects directly
  slub: Remove slabs_node() function
  slub: Remove CONFIG_SMP defined check
  slub: Put objects_show() into CONFIG_SLUB_DEBUG enabled block
  slub: Correct the error code when slab_kset is NULL
  mm/slab: correct return values in comment for _kmem_cache_create()

This modifies our user mode stack expansion code to always take the
mmap_lock for writing before modifying the VM layout.

It's actually something we always technically should have done, but
because we didn't strictly need it, we were being lazy ("opportunistic"
sounds so much better, doesn't it?) about things, and had this hack in
place where we would extend the stack vma in-place without doing the
proper locking.

And it worked fine.  We just needed to change vm_start (or, in the case
of grow-up stacks, vm_end) and together with some special ad-hoc locking
using the anon_vma lock and the mm->page_table_lock, it all was fairly
straightforward.

That is, it was all fine until Ruihan Li pointed out that now that the
vma layout uses the maple tree code, we *really* don't just change
vm_start and vm_end any more, and the locking really is broken.  Oops.

It's not actually all _that_ horrible to fix this once and for all, and
do proper locking, but it's a bit painful.  We have basically three
different cases of stack expansion, and they all work just a bit
differently:

 - the common and obvious case is the page fault handling. It's actually
   fairly simple and straightforward, except for the fact that we have
   something like 24 different versions of it, and you end up in a maze
   of twisty little passages, all alike.

 - the simplest case is the execve() code that creates a new stack.
   There are no real locking concerns because it's all in a private new
   VM that hasn't been exposed to anybody, but lockdep still can end up
   unhappy if you get it wrong.

 - and finally, we have GUP and page pinning, which shouldn't really be
   expanding the stack in the first place, but in addition to execve()
   we also use it for ptrace(). And debuggers do want to possibly access
   memory under the stack pointer and thus need to be able to expand the
   stack as a special case.

None of these cases are exactly complicated, but the page fault case in
particular is just repeated slightly differently many many times.  And
ia64 in particular has a fairly complicated situation where you can have
both a regular grow-down stack _and_ a special grow-up stack for the
register backing store.

So to make this slightly more manageable, the bulk of this series is to
first create a helper function for the most common page fault case, and
convert all the straightforward architectures to it.

Thus the new 'lock_mm_and_find_vma()' helper function, which ends up
being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa.  So we not only convert more
than half the architectures, we now have more shared code and avoid some
of those twisty little passages.

And largely due to this common helper function, the full diffstat of
this series ends up deleting more lines than it adds.

That still leaves eight architectures (ia64, m68k, microblaze, openrisc,
parisc, s390, sparc64 and um) that end up doing 'expand_stack()'
manually because they are doing something slightly different from the
normal pattern.  Along with the couple of special cases in execve() and
GUP.

So there's a couple of patches that first create 'locked' helper
versions of the stack expansion functions, so that there's a obvious
path forward in the conversion.  The execve() case is then actually
pretty simple, and is a nice cleanup from our old "grow-up stackls are
special, because at execve time even they grow down".

The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because
it's just more straightforward to write out the stack expansion there
manually, instead od having get_user_pages_remote() do it for us in some
situations but not others and have to worry about locking rules for GUP.

And the final step is then to just convert the remaining odd cases to a
new world order where 'expand_stack()' is called with the mmap_lock held
for reading, but where it might drop it and upgrade it to a write, only
to return with it held for reading (in the success case) or with it
completely dropped (in the failure case).

In the process, we remove all the stack expansion from GUP (where
dropping the lock wouldn't be ok without special rules anyway), and add
it in manually to __access_remote_vm() for ptrace().

Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases.
Everything else here felt pretty straightforward, but the ia64 rules for
stack expansion are really quite odd and very different from everything
else.  Also thanks to Vegard Nossum who caught me getting one of those
odd conditions entirely the wrong way around.

Anyway, I think I want to actually move all the stack expansion code to
a whole new file of its own, rather than have it split up between
mm/mmap.c and mm/memory.c, but since this will have to be backported to
the initial maple tree vma introduction anyway, I tried to keep the
patches _fairly_ minimal.

Also, while I don't think it's valid to expand the stack from GUP, the
final patch in here is a "warn if some crazy GUP user wants to try to
expand the stack" patch.  That one will be reverted before the final
release, but it's left to catch any odd cases during the merge window
and release candidates.

Reported-by: Ruihan Li <lrh2000@pku.edu.cn>

* branch 'expand-stack':
  gup: add warning if some caller would seem to want stack expansion
  mm: always expand the stack with the mmap write lock held
  execve: expand new process stack manually ahead of time
  mm: make find_extend_vma() fail if write lock not held
  powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
  mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
  arm/mm: Convert to using lock_mm_and_find_vma()
  riscv/mm: Convert to using lock_mm_and_find_vma()
  mips/mm: Convert to using lock_mm_and_find_vma()
  powerpc/mm: Convert to using lock_mm_and_find_vma()
  arm64/mm: Convert to using lock_mm_and_find_vma()
  mm: make the page fault mmap locking killable
  mm: introduce new 'lock_mm_and_find_vma()' page fault helper

Pull hardening updates from Kees Cook:
 "There are three areas of note:

  A bunch of strlcpy()->strscpy() conversions ended up living in my tree
  since they were either Acked by maintainers for me to carry, or got
  ignored for multiple weeks (and were trivial changes).

  The compiler option '-fstrict-flex-arrays=3' has been enabled
  globally, and has been in -next for the entire devel cycle. This
  changes compiler diagnostics (though mainly just -Warray-bounds which
  is disabled) and potential UBSAN_BOUNDS and FORTIFY _warning_
  coverage. In other words, there are no new restrictions, just
  potentially new warnings. Any new FORTIFY warnings we've seen have
  been fixed (usually in their respective subsystem trees). For more
  details, see commit df8fc4e934c12b.

  The under-development compiler attribute __counted_by has been added
  so that we can start annotating flexible array members with their
  associated structure member that tracks the count of flexible array
  elements at run-time. It is possible (likely?) that the exact syntax
  of the attribute will change before it is finalized, but GCC and Clang
  are working together to sort it out. Any changes can be made to the
  macro while we continue to add annotations.

  As an example of that last case, I have a treewide commit waiting with
  such annotations found via Coccinelle:

    https://git.kernel.org/linus/adc5b3cb48a049563dc673f348eab7b6beba8a9b

  Also see commit dd06e72e68bcb4 for more details.

  Summary:

   - Fix KMSAN vs FORTIFY in strlcpy/strlcat (Alexander Potapenko)

   - Convert strreplace() to return string start (Andy Shevchenko)

   - Flexible array conversions (Arnd Bergmann, Wyes Karny, Kees Cook)

   - Add missing function prototypes seen with W=1 (Arnd Bergmann)

   - Fix strscpy() kerndoc typo (Arne Welzel)

   - Replace strlcpy() with strscpy() across many subsystems which were
     either Acked by respective maintainers or were trivial changes that
     went ignored for multiple weeks (Azeem Shaikh)

   - Remove unneeded cc-option test for UBSAN_TRAP (Nick Desaulniers)

   - Add KUnit tests for strcat()-family

   - Enable KUnit tests of FORTIFY wrappers under UML

   - Add more complete FORTIFY protections for strlcat()

   - Add missed disabling of FORTIFY for all arch purgatories.

   - Enable -fstrict-flex-arrays=3 globally

   - Tightening UBSAN_BOUNDS when using GCC

   - Improve checkpatch to check for strcpy, strncpy, and fake flex
     arrays

   - Improve use of const variables in FORTIFY

   - Add requested struct_size_t() helper for types not pointers

   - Add __counted_by macro for annotating flexible array size members"

* tag 'hardening-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (54 commits)
  netfilter: ipset: Replace strlcpy with strscpy
  uml: Replace strlcpy with strscpy
  um: Use HOST_DIR for mrproper
  kallsyms: Replace all non-returning strlcpy with strscpy
  sh: Replace all non-returning strlcpy with strscpy
  of/flattree: Replace all non-returning strlcpy with strscpy
  sparc64: Replace all non-returning strlcpy with strscpy
  Hexagon: Replace all non-returning strlcpy with strscpy
  kobject: Use return value of strreplace()
  lib/string_helpers: Change returned value of the strreplace()
  jbd2: Avoid printing outside the boundary of the buffer
  checkpatch: Check for 0-length and 1-element arrays
  riscv/purgatory: Do not use fortified string functions
  s390/purgatory: Do not use fortified string functions
  x86/purgatory: Do not use fortified string functions
  acpi: Replace struct acpi_table_slit 1-element array with flex-array
  clocksource: Replace all non-returning strlcpy with strscpy
  string: use __builtin_memcpy() in strlcpy/strlcat
  staging: most: Replace all non-returning strlcpy with strscpy
  drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy
  ...

Pull landlock updates from Mickaël Salaün:
 "Add support for Landlock to UML.

  To do this, this fixes the way hostfs manages inodes according to the
  underlying filesystem [1]. They are now properly handled as for other
  filesystems, which enables Landlock support (and probably other
  features).

  This also extends Landlock's tests with 6 pseudo filesystems,
  including hostfs"

[1] https://lore.kernel.org/all/20230612191430.339153-1-mic@digikod.net/

* tag 'landlock-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
  selftests/landlock: Add hostfs tests
  selftests/landlock: Add tests for pseudo filesystems
  selftests/landlock: Make mounts configurable
  selftests/landlock: Add supports_filesystem() helper
  selftests/landlock: Don't create useless file layouts
  hostfs: Fix ephemeral inodes

This finishes the job of always holding the mmap write lock when
extending the user stack vma, and removes the 'write_locked' argument
from the vm helper functions again.

For some cases, we just avoid expanding the stack at all: drivers and
page pinning really shouldn't be extending any stacks.  Let's see if any
strange users really wanted that.

It's worth noting that architectures that weren't converted to the new
lock_mm_and_find_vma() helper function are left using the legacy
"expand_stack()" function, but it has been changed to drop the mmap_lock
and take it for writing while expanding the vma.  This makes it fairly
straightforward to convert the remaining architectures.

As a result of dropping and re-taking the lock, the calling conventions
for this function have also changed, since the old vma may no longer be
valid.  So it will now return the new vma if successful, and NULL - and
the lock dropped - if the area could not be extended.

Tested-by: Vegard Nossum <vegard.nossum@oracle.com>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # ia64
Tested-by: Frank Scheiner <frank.scheiner@web.de> # ia64
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 boot updates from Thomas Gleixner:
 "Initialize FPU late.

  Right now FPU is initialized very early during boot. There is no real
  requirement to do so. The only requirement is to have it done before
  alternatives are patched.

  That's done in check_bugs() which does way more than what the function
  name suggests.

  So first rename check_bugs() to arch_cpu_finalize_init() which makes
  it clear what this is about.

  Move the invocation of arch_cpu_finalize_init() earlier in
  start_kernel() as it has to be done before fork_init() which needs to
  know the FPU register buffer size.

  With those prerequisites the FPU initialization can be moved into
  arch_cpu_finalize_init(), which removes it from the early and fragile
  part of the x86 bringup"

* tag 'x86-boot-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mem_encrypt: Unbreak the AMD_MEM_ENCRYPT=n build
  x86/fpu: Move FPU initialization into arch_cpu_finalize_init()
  x86/fpu: Mark init functions __init
  x86/fpu: Remove cpuinfo argument from init functions
  x86/init: Initialize signal frame size late
  init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()
  init: Invoke arch_cpu_finalize_init() earlier
  init: Remove check_bugs() leftovers
  um/cpu: Switch to arch_cpu_finalize_init()
  sparc/cpu: Switch to arch_cpu_finalize_init()
  sh/cpu: Switch to arch_cpu_finalize_init()
  mips/cpu: Switch to arch_cpu_finalize_init()
  m68k/cpu: Switch to arch_cpu_finalize_init()
  loongarch/cpu: Switch to arch_cpu_finalize_init()
  ia64/cpu: Switch to arch_cpu_finalize_init()
  ARM: cpu: Switch to arch_cpu_finalize_init()
  x86/cpu: Switch to arch_cpu_finalize_init()
  init: Provide arch_cpu_finalize_init()