linux.git/mm/Kconfig, branch v6.5 Linux kernel source tree Merge tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab 2023-06-29T23:34:12+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-06-29T23:34:12+00:00 632f54b4d60bfe0701f43d0bc387928de6e3dcfb 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() 
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()
Merge branch 'expand-stack' 2023-06-29T03:35:21+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-06-29T03:35:21+00:00 9471f1f2f50282b9e8f59198ec6bb738b4ccc009 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 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
mm: introduce new 'lock_mm_and_find_vma()' page fault helper 2023-06-24T21:12:54+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-06-15T22:17:36+00:00 c2508ec5a58db67093f4fb8bf89a9a7c53a109e9 .. and make x86 use it. This basically extracts the existing x86 "find and expand faulting vma" code, but extends it to also take the mmap lock for writing in case we actually do need to expand the vma. We've historically short-circuited that case, and have some rather ugly special logic to serialize the stack segment expansion (since we only hold the mmap lock for reading) that doesn't match the normal VM locking. That slight violation of locking worked well, right up until it didn't: the maple tree code really does want proper locking even for simple extension of an existing vma. So extract the code for "look up the vma of the fault" from x86, fix it up to do the necessary write locking, and make it available as a helper function for other architectures that can use the common helper. Note: I say "common helper", but it really only handles the normal stack-grows-down case. Which is all architectures except for PA-RISC and IA64. So some rare architectures can't use the helper, but if they care they'll just need to open-code this logic. It's also worth pointing out that this code really would like to have an optimistic "mmap_upgrade_trylock()" to make it quicker to go from a read-lock (for the common case) to taking the write lock (for having to extend the vma) in the normal single-threaded situation where there is no other locking activity. But that _is_ all the very uncommon special case, so while it would be nice to have such an operation, it probably doesn't matter in reality. I did put in the skeleton code for such a possible future expansion, even if it only acts as pseudo-documentation for what we're doing. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
.. and make x86 use it.

This basically extracts the existing x86 "find and expand faulting vma"
code, but extends it to also take the mmap lock for writing in case we
actually do need to expand the vma.

We've historically short-circuited that case, and have some rather ugly
special logic to serialize the stack segment expansion (since we only
hold the mmap lock for reading) that doesn't match the normal VM
locking.

That slight violation of locking worked well, right up until it didn't:
the maple tree code really does want proper locking even for simple
extension of an existing vma.

So extract the code for "look up the vma of the fault" from x86, fix it
up to do the necessary write locking, and make it available as a helper
function for other architectures that can use the common helper.

Note: I say "common helper", but it really only handles the normal
stack-grows-down case.  Which is all architectures except for PA-RISC
and IA64.  So some rare architectures can't use the helper, but if they
care they'll just need to open-code this logic.

It's also worth pointing out that this code really would like to have an
optimistic "mmap_upgrade_trylock()" to make it quicker to go from a
read-lock (for the common case) to taking the write lock (for having to
extend the vma) in the normal single-threaded situation where there is
no other locking activity.

But that _is_ all the very uncommon special case, so while it would be
nice to have such an operation, it probably doesn't matter in reality.
I did put in the skeleton code for such a possible future expansion,
even if it only acts as pseudo-documentation for what we're doing.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: zswap: support exclusive loads 2023-06-19T23:19:05+00:00 Yosry Ahmed yosryahmed@google.com 2023-06-07T19:51:43+00:00 b9c91c43412f2e07a5287dfe7027acdd8fb0b1ef Commit 71024cb4a0bf ("frontswap: remove frontswap_tmem_exclusive_gets") removed support for exclusive loads from frontswap as it was not used. Bring back exclusive loads support to frontswap by adding an "exclusive" output parameter to frontswap_ops->load. On the zswap side, add a module parameter to enable/disable exclusive loads, and a config option to control the boot default value. Refactor zswap entry invalidation in zswap_frontswap_invalidate_page() into zswap_invalidate_entry() to reuse it in zswap_frontswap_load() if exclusive loads are enabled. With exclusive loads, we avoid having two copies of the same page in memory (compressed & uncompressed) after faulting it in from zswap. On the other hand, if the page is to be reclaimed again without being dirtied, it will be re-compressed. Compression is not usually slow, and a page that was just faulted in is less likely to be reclaimed again soon. Link: https://lkml.kernel.org/r/20230607195143.1473802-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Suggested-by: Yu Zhao <yuzhao@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Commit 71024cb4a0bf ("frontswap: remove frontswap_tmem_exclusive_gets")
removed support for exclusive loads from frontswap as it was not used. 
Bring back exclusive loads support to frontswap by adding an "exclusive"
output parameter to frontswap_ops->load.

On the zswap side, add a module parameter to enable/disable exclusive
loads, and a config option to control the boot default value.  Refactor
zswap entry invalidation in zswap_frontswap_invalidate_page() into
zswap_invalidate_entry() to reuse it in zswap_frontswap_load() if
exclusive loads are enabled.

With exclusive loads, we avoid having two copies of the same page in
memory (compressed & uncompressed) after faulting it in from zswap.  On
the other hand, if the page is to be reclaimed again without being
dirtied, it will be re-compressed.  Compression is not usually slow, and a
page that was just faulted in is less likely to be reclaimed again soon.

Link: https://lkml.kernel.org/r/20230607195143.1473802-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Suggested-by: Yu Zhao <yuzhao@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Merge branches 'slab/for-6.5/prandom', 'slab/for-6.5/slab_no_merge' and 'slab/for-6.5/slab-deprecate' into slab/for-next 2023-06-16T09:05:59+00:00 Vlastimil Babka vbabka@suse.cz 2023-06-16T09:05:59+00:00 7bc162d5cc4de5c33c5570dba2719a01506a9fd0 Merge the feature branches scheduled for 6.5: - replace the usage of weak PRNGs, by David Keisar Schmidt - introduce the SLAB_NO_MERGE kmem_cache flag, by Jesper Dangaard Brouer - deprecate CONFIG_SLAB, with a planned removal, by myself 
Merge the feature branches scheduled for 6.5:

- replace the usage of weak PRNGs, by David Keisar Schmidt

- introduce the SLAB_NO_MERGE kmem_cache flag, by Jesper Dangaard Brouer

- deprecate CONFIG_SLAB, with a planned removal, by myself
mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED 2023-05-26T17:01:47+00:00 Vlastimil Babka vbabka@suse.cz 2023-05-23T07:06:34+00:00 eb07c4f39c3e858a7d0cc4bb15b8a304f83f0497 As discussed at LSF/MM [1] [2] and with no objections raised there, deprecate the SLAB allocator. Rename the user-visible option so that users with CONFIG_SLAB=y get a new prompt with explanation during make oldconfig, while make olddefconfig will just switch to SLUB. In all defconfigs with CONFIG_SLAB=y remove the line so those also switch to SLUB. Regressions due to the switch should be reported to linux-mm and slab maintainers. [1] https://lore.kernel.org/all/4b9fc9c6-b48c-198f-5f80-811a44737e5f@suse.cz/ [2] https://lwn.net/Articles/932201/ Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Acked-by: Helge Deller <deller@gmx.de> # parisc 
As discussed at LSF/MM [1] [2] and with no objections raised there,
deprecate the SLAB allocator. Rename the user-visible option so that
users with CONFIG_SLAB=y get a new prompt with explanation during make
oldconfig, while make olddefconfig will just switch to SLUB.

In all defconfigs with CONFIG_SLAB=y remove the line so those also
switch to SLUB. Regressions due to the switch should be reported to
linux-mm and slab maintainers.

[1] https://lore.kernel.org/all/4b9fc9c6-b48c-198f-5f80-811a44737e5f@suse.cz/
[2] https://lwn.net/Articles/932201/

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: Helge Deller <deller@gmx.de> # parisc
mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR 2023-05-24T13:38:17+00:00 Vlastimil Babka vbabka@suse.cz 2023-05-23T07:26:35+00:00 d2e527f0d8d1124b1fab93e2e7b2c6a114c0e5a2 With SLOB removed, both remaining allocators support hardened usercopy, so remove the config and associated #ifdef. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> 
With SLOB removed, both remaining allocators support hardened usercopy,
so remove the config and associated #ifdef.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2023-04-28T02:42:02+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-04-28T02:42:02+00:00 7fa8a8ee9400fe8ec188426e40e481717bc5e924 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 ... 
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
  ...
Merge tag 'slab-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab 2023-04-25T20:00:41+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-04-25T20:00:41+00:00 736b378b29d89c8c3567fa4b2e948be5568aebb8 Pull slab updates from Vlastimil Babka: "The main change is naturally the SLOB removal. Since its deprecation in 6.2 I've seen no complaints so hopefully SLUB_(TINY) works well for everyone and we can proceed. Besides the code cleanup, the main immediate benefit will be allowing kfree() family of function to work on kmem_cache_alloc() objects, which was incompatible with SLOB. This includes kfree_rcu() which had no kmem_cache_free_rcu() counterpart yet and now it shouldn't be necessary anymore. Besides that, there are several small code and comment improvements from Thomas, Thorsten and Vernon" * tag 'slab-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slab: document kfree() as allowed for kmem_cache_alloc() objects mm/slob: remove slob.c mm/slab: remove CONFIG_SLOB code from slab common code mm, pagemap: remove SLOB and SLQB from comments and documentation mm, page_flags: remove PG_slob_free mm/slob: remove CONFIG_SLOB mm/slub: fix help comment of SLUB_DEBUG mm: slub: make kobj_type structure constant slab: Adjust comment after refactoring of gfp.h 
Pull slab updates from Vlastimil Babka:
 "The main change is naturally the SLOB removal. Since its deprecation
  in 6.2 I've seen no complaints so hopefully SLUB_(TINY) works well for
  everyone and we can proceed.

  Besides the code cleanup, the main immediate benefit will be allowing
  kfree() family of function to work on kmem_cache_alloc() objects,
  which was incompatible with SLOB. This includes kfree_rcu() which had
  no kmem_cache_free_rcu() counterpart yet and now it shouldn't be
  necessary anymore.

  Besides that, there are several small code and comment improvements
  from Thomas, Thorsten and Vernon"

* tag 'slab-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab: document kfree() as allowed for kmem_cache_alloc() objects
  mm/slob: remove slob.c
  mm/slab: remove CONFIG_SLOB code from slab common code
  mm, pagemap: remove SLOB and SLQB from comments and documentation
  mm, page_flags: remove PG_slob_free
  mm/slob: remove CONFIG_SLOB
  mm/slub: fix help comment of SLUB_DEBUG
  mm: slub: make kobj_type structure constant
  slab: Adjust comment after refactoring of gfp.h
mm/hugetlb_vmemmap: rename ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP 2023-04-18T23:30:09+00:00 Aneesh Kumar K.V aneesh.kumar@linux.ibm.com 2023-04-12T05:00:25+00:00 0b376f1e0ff555435597fa16823ae0f30b2883e3 Now we use ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP config option to indicate devdax and hugetlb vmemmap optimization support. Hence rename that to a generic ARCH_WANT_OPTIMIZE_VMEMMAP Link: https://lkml.kernel.org/r/20230412050025.84346-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Tarun Sahu <tsahu@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Now we use ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP config option to
indicate devdax and hugetlb vmemmap optimization support.  Hence rename
that to a generic ARCH_WANT_OPTIMIZE_VMEMMAP

Link: https://lkml.kernel.org/r/20230412050025.84346-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Tarun Sahu <tsahu@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>