Nested file systems, that is those which invoke call_mmap() within their
own f_op->mmap() handlers, may encounter underlying file systems which
provide the f_op->mmap_prepare() hook introduced by commit c84bf6dd2b83
("mm: introduce new .mmap_prepare() file callback").

We have a chicken-and-egg scenario here - until all file systems are
converted to using .mmap_prepare(), we cannot convert these nested
handlers, as we can't call f_op->mmap from an .mmap_prepare() hook.

So we have to do it the other way round - invoke the .mmap_prepare() hook
from an .mmap() one.

in order to do so, we need to convert VMA state into a struct vm_area_desc
descriptor, invoking the underlying file system's f_op->mmap_prepare()
callback passing a pointer to this, and then setting VMA state accordingly
and safely.

This patch achieves this via the compat_vma_mmap_prepare() function, which
we invoke from call_mmap() if f_op->mmap_prepare() is specified in the
passed in file pointer.

We place the fundamental logic into mm/vma.h where VMA manipulation
belongs.  We also update the VMA userland tests to accommodate the
changes.

The compat_vma_mmap_prepare() function and its associated machinery is
temporary, and will be removed once the conversion of file systems is
complete.

We carefully place this code so it can be used with CONFIG_MMU and also
with cutting edge nommu silicon.

[akpm@linux-foundation.org: export compat_vma_mmap_prepare tp fix build]
[lorenzo.stoakes@oracle.com: remove unused declarations]
  Link: https://lkml.kernel.org/r/ac3ae324-4c65-432a-8c6d-2af988b18ac8@lucifer.local
Link: https://lkml.kernel.org/r/20250609165749.344976-1-lorenzo.stoakes@oracle.com
Fixes: c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback").
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Closes: https://lore.kernel.org/linux-mm/CAG48ez04yOEVx1ekzOChARDDBZzAKwet8PEoPM4Ln3_rk91AzQ@mail.gmail.com/
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull sysctl updates from Joel Granados:

 - Move vm_table members out of kernel/sysctl.c

   All vm_table array members have moved to their respective subsystems
   leading to the removal of vm_table from kernel/sysctl.c. This
   increases modularity by placing the ctl_tables closer to where they
   are actually used and at the same time reducing the chances of merge
   conflicts in kernel/sysctl.c.

 - ctl_table range fixes

   Replace the proc_handler function that checks variable ranges in
   coredump_sysctls and vdso_table with the one that actually uses the
   extra{1,2} pointers as min/max values. This tightens the range of the
   values that users can pass into the kernel effectively preventing
   {under,over}flows.

 - Misc fixes

   Correct grammar errors and typos in test messages. Update sysctl
   files in MAINTAINERS. Constified and removed array size in
   declaration for alignment_tbl

* tag 'sysctl-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: (22 commits)
  selftests/sysctl: fix wording of help messages
  selftests: fix spelling/grammar errors in sysctl/sysctl.sh
  MAINTAINERS: Update sysctl file list in MAINTAINERS
  sysctl: Fix underflow value setting risk in vm_table
  coredump: Fixes core_pipe_limit sysctl proc_handler
  sysctl: remove unneeded include
  sysctl: remove the vm_table
  sh: vdso: move the sysctl to arch/sh/kernel/vsyscall/vsyscall.c
  x86: vdso: move the sysctl to arch/x86/entry/vdso/vdso32-setup.c
  fs: dcache: move the sysctl to fs/dcache.c
  sunrpc: simplify rpcauth_cache_shrink_count()
  fs: drop_caches: move sysctl to fs/drop_caches.c
  fs: fs-writeback: move sysctl to fs/fs-writeback.c
  mm: nommu: move sysctl to mm/nommu.c
  security: min_addr: move sysctl to security/min_addr.c
  mm: mmap: move sysctl to mm/mmap.c
  mm: util: move sysctls to mm/util.c
  mm: vmscan: move vmscan sysctls to mm/vmscan.c
  mm: swap: move sysctl to mm/swap.c
  mm: filemap: move sysctl to mm/filemap.c
  ...

Pull slab updates from Vlastimil Babka:

 - Move the TINY_RCU kvfree_rcu() implementation from RCU to SLAB
   subsystem and cleanup its integration (Vlastimil Babka)

   Following the move of the TREE_RCU batching kvfree_rcu()
   implementation in 6.14, move also the simpler TINY_RCU variant.
   Refactor the #ifdef guards so that the simple implementation is also
   used with SLUB_TINY.

   Remove the need for RCU to recognize fake callback function pointers
   (__is_kvfree_rcu_offset()) when handling call_rcu() by implementing a
   callback that calculates the object's address from the embedded
   rcu_head address without knowing its offset.

 - Improve kmalloc cache randomization in kvmalloc (GONG Ruiqi)

   Due to an extra layer of function call, all kvmalloc() allocations
   used the same set of random caches. Thanks to moving the kvmalloc()
   implementation to slub.c, this is improved and randomization now
   works for kvmalloc.

 - Various improvements to debugging, testing and other cleanups (Hyesoo
   Yu, Lilith Gkini, Uladzislau Rezki, Matthew Wilcox, Kevin Brodsky, Ye
   Bin)

* tag 'slab-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  slub: Handle freelist cycle in on_freelist()
  mm/slab: call kmalloc_noprof() unconditionally in kmalloc_array_noprof()
  slab: Mark large folios for debugging purposes
  kunit, slub: Add test_kfree_rcu_wq_destroy use case
  mm, slab: cleanup slab_bug() parameters
  mm: slub: call WARN() when detecting a slab corruption
  mm: slub: Print the broken data before restoring them
  slab: Achieve better kmalloc caches randomization in kvmalloc
  slab: Adjust placement of __kvmalloc_node_noprof
  mm/slab: simplify SLAB_* flag handling
  slab: don't batch kvfree_rcu() with SLUB_TINY
  rcu, slab: use a regular callback function for kvfree_rcu
  rcu: remove trace_rcu_kvfree_callback
  slab, rcu: move TINY_RCU variant of kvfree_rcu() to SLAB

Pre-content hooks in page faults introduces potential deadlock of HSM
handler in userspace with filesystem freezing.

The requirement with pre-content event is that for every accessed file
range an event covering at least this range will be generated at least
once before the file data is accesses.

In preparation to disabling pre-content event hooks on page faults,
add pre-content hooks at mmap() variants for the entire mmaped range,
so HSM can fill content when user requests to map a portion of the file.

Note that exec() variant also calls vm_mmap_pgoff() internally to map
code sections, so pre-content hooks are also generated in this case.

Link: https://lore.kernel.org/linux-fsdevel/7ehxrhbvehlrjwvrduoxsao5k3x4aw275patsb3krkwuq573yv@o2hskrfawbnc/
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250312073852.2123409-2-amir73il@gmail.com

Move __kvmalloc_node_noprof (as well as kvfree*, kvrealloc_noprof and
kmalloc_gfp_adjust for consistency) into mm/slub.c so that it can
directly invoke __do_kmalloc_node, which is needed for the next patch.

No functional changes intended.

Signed-off-by: GONG Ruiqi <gongruiqi1@huawei.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

This moves all util related sysctls to mm/util.c, as part of the
kernel/sysctl.c cleaning, also removes redundant external
variable declarations and function declarations.

Signed-off-by: Kaixiong Yu <yukaixiong@huawei.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>

It isn't always entirely clear to users the difference between do_mmap(),
mmap_region() and vm_mmap(), so add comments to clarify what's going on in
each.

This is compounded by the fact that we actually allow callers external to
mm to invoke both do_mmap() and mmap_region() (!), the latter of which is
really strictly speaking an internal memory mapping implementation detail.

Link: https://lkml.kernel.org/r/20241212113152.28849-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Since the string data to copy from userspace is likely less than PAGE_SIZE
bytes, replace GFP_KERNEL with GFP_USER like commit 6c2c97a24f09
("memdup_user(): switch to GFP_USER") does and add __GFP_NOWARN like
commit 6c8fcc096be9 ("mm: don't let userspace spam allocations warnings")
does.  Also, use dedicated slab buckets like commit d73778e4b867
("mm/util: Use dedicated slab buckets for memdup_user()") does.

Link: https://lkml.kernel.org/r/014cd694-cc27-4a07-a34a-2ae95d744515@I-love.SAKURA.ne.jp
Reported-by: syzbot+7e12e97b36154c54414b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7e12e97b36154c54414b
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...

This function doesn't modify any of its arguments, so if we make a few
other functions take const pointers, we can make page_address_in_vma()
take const pointers too.  All of its callers have the containing folio
already, so pass that in as an argument instead of recalculating it.  Also
add kernel-doc

Link: https://lkml.kernel.org/r/20241005200121.3231142-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>