Pull m68knommu updates from Greg Ungerer:
 "A few changes, most of them related to fixing warnings when compiling
  with "W=1". These follow up Geert's recent changes for M68K for this
  too. These ones complete the fixes for the nommu and ColdFire specific
  code.

  Also a couple of other fixes to improve ROM default addressing and
  compiling for the Cleopatra boards.

  Summary:

   - improve default Kconfig ROM section settings

   - fix compilation for some Cleopatra boards

   - fixes and cleanups for warnings compiling with 'W=1'"

* tag 'm68knommu-for-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: 68000: fix warning in timer code
  m68k: 68000: fix warnings in 68000 interrupt handling
  m68k: coldfire: remove unused variable in MMU code
  m68k: coldfire: fix warnings in uboot argument processing
  m68k: coldfire: make mcf_maskimr() static
  m68k: coldfire: ensure gpio prototypes visible
  m68k: coldfire: add and use "vectors.h"
  m68knommu: fix compilation for ColdFire/Cleopatra boards
  m68knommu: improve config ROM setting defaults

When building with W=1:

  CC      arch/m68k/mm/mcfmmu.o
arch/m68k/mm/mcfmmu.c: In function ‘paging_init’:
arch/m68k/mm/mcfmmu.c:41:30: warning: variable ‘bootmem_end’ set but not used [-Wunused-but-set-variable]
  unsigned long next_pgtable, bootmem_end;
                              ^~~~~~~~~~~

Remove variable bootmem_end and its unused setting.

Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

When building with W=1:

    arch/m68k/sun3/idprom.c:86:6: warning: no previous prototype for ‘sun3_get_model’ [-Wmissing-prototypes]
       86 | void sun3_get_model(char *model)
	  |      ^~~~~~~~~~~~~~
    arch/m68k/sun3/config.c:53:24: warning: no previous prototype for ‘sun3_init’ [-Wmissing-prototypes]
       53 | asmlinkage void __init sun3_init(void)
	  |                        ^~~~~~~~~
    arch/m68k/sun3/mmu_emu.c:117:6: warning: no previous prototype for ‘print_pte_vaddr’ [-Wmissing-prototypes]
      117 | void print_pte_vaddr (unsigned long vaddr)
	  |      ^~~~~~~~~~~~~~~
    arch/m68k/sun3/mmu_emu.c:126:13: warning: no previous prototype for ‘mmu_emu_init’ [-Wmissing-prototypes]
      126 | void __init mmu_emu_init(unsigned long bootmem_end)
	  |             ^~~~~~~~~~~~
    arch/m68k/sun3/mmu_emu.c:353:5: warning: no previous prototype for ‘mmu_emu_handle_fault’ [-Wmissing-prototypes]
      353 | int mmu_emu_handle_fault (unsigned long vaddr, int read_flag, int kernel_fault)
	  |     ^~~~~~~~~~~~~~~~~~~~
    arch/m68k/sun3/leds.c:6:6: warning: no previous prototype for ‘sun3_leds’ [-Wmissing-prototypes]
	6 | void sun3_leds(unsigned char byte)
	  |      ^~~~~~~~~
    arch/m68k/sun3/intersil.c:27:5: warning: no previous prototype for ‘sun3_hwclk’ [-Wmissing-prototypes]
       27 | int sun3_hwclk(int set, struct rtc_time *t)
	  |     ^~~~~~~~~~
    arch/m68k/sun3x/config.c:30:6: warning: no previous prototype for ‘sun3_leds’ [-Wmissing-prototypes]
       30 | void sun3_leds(unsigned char byte)
	  |      ^~~~~~~~~

Fix this by introducing a new header file "sun3.h" for holding the
prototypes of functions implemented in arch/m68k/sun3/ and
arch/m68k/sun3x/.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/87856ef9ef8955f459fb691faca921c0a688bc80.1694613528.git.geert@linux-m68k.org

When building with W=1:

    arch/m68k/mm/fault.c:22:5: warning: no previous prototype for ‘send_fault_sig’ [-Wmissing-prototypes]
       22 | int send_fault_sig(struct pt_regs *regs)
	  |     ^~~~~~~~~~~~~~
    arch/m68k/mm/fault.c:68:5: warning: no previous prototype for ‘do_page_fault’ [-Wmissing-prototypes]
       68 | int do_page_fault(struct pt_regs *regs, unsigned long address,
	  |     ^~~~~~~~~~~~~

Fix this by introducing a new header file "fault.h" for holding the
prototypes of functions implemented in arch/m68k/mm/fault.c.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/ef004b8cfe4aac892aa0fb7714c2ed81a02a9b89.1694613528.git.geert@linux-m68k.org

When building with W=1:

    arch/m68k/mm/hwtest.c:29:5: warning: no previous prototype for ‘hwreg_present’ [-Wmissing-prototypes]
       29 | int hwreg_present(volatile void *regp)
	  |     ^~~~~~~~~~~~~
    arch/m68k/mm/hwtest.c:62:5: warning: no previous prototype for ‘hwreg_write’ [-Wmissing-prototypes]
       62 | int hwreg_write(volatile void *regp, unsigned short val)
	  |     ^~~~~~~~~~~

Fix this by including <asm/hwtest.h>.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/fbd87d8e8d1e8cbe7d56941a8a1d7d82b53010d0.1694613528.git.geert@linux-m68k.org

Add PFN_PTE_SHIFT, update_mmu_cache_range(), flush_icache_pages() and
flush_dcache_folio().

Link: https://lkml.kernel.org/r/20230802151406.3735276-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions.  Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Link: https://lkml.kernel.org/r/20230807230513.102486-23-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull asm-generic updates from Arnd Bergmann:
 "These are cleanups for architecture specific header files:

   - the comments in include/linux/syscalls.h have gone out of sync and
     are really pointless, so these get removed

   - The asm/bitsperlong.h header no longer needs to be architecture
     specific on modern compilers, so use a generic version for newer
     architectures that use new enough userspace compilers

   - A cleanup for virt_to_pfn/virt_to_bus to have proper type checking,
     forcing the use of pointers"

* tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  syscalls: Remove file path comments from headers
  tools arch: Remove uapi bitsperlong.h of hexagon and microblaze
  asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch
  m68k/mm: Make pfn accessors static inlines
  arm64: memory: Make virt_to_pfn() a static inline
  ARM: mm: Make virt_to_pfn() a static inline
  asm-generic/page.h: Make pfn accessors static inlines
  xen/netback: Pass (void *) to virt_to_page()
  netfs: Pass a pointer to virt_to_page()
  cifs: Pass a pointer to virt_to_page() in cifsglob
  cifs: Pass a pointer to virt_to_page()
  riscv: mm: init: Pass a pointer to virt_to_page()
  ARC: init: Pass a pointer to virt_to_pfn() in init
  m68k: Pass a pointer to virt_to_pfn() virt_to_page()
  fs/proc/kcore.c: Pass a pointer to virt_addr_valid()

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

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>