Commit Graph

1233 Commits

Author SHA1 Message Date
Vlastimil Babka
3f1dd33f99 mm, slab: suppress warnings in test_leak_destroy kunit test
The test_leak_destroy kunit test intends to test the detection of stray
objects in kmem_cache_destroy(), which normally produces a warning. The
other slab kunit tests suppress the warnings in the kunit test context,
so suppress warnings and related printk output in this test as well.
Automated test running environments then don't need to learn to filter
the warnings.

Also rename the test's kmem_cache, the name was wrongly copy-pasted from
test_kfree_rcu.

Fixes: 4e1c44b3db ("kunit, slub: add test_kfree_rcu() and test_leak_destroy()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202408251723.42f3d902-oliver.sang@intel.com
Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Closes: https://lore.kernel.org/all/CAB=+i9RHHbfSkmUuLshXGY_ifEZg9vCZi3fqr99+kmmnpDus7Q@mail.gmail.com/
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/all/6fcb1252-7990-4f0d-8027-5e83f0fb9409@roeck-us.net/
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-10-02 16:28:46 +02:00
Linus Torvalds
bdf56c7580 slab updates for 6.12
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Merge tag 'slab-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:
 "This time it's mostly refactoring and improving APIs for slab users in
  the kernel, along with some debugging improvements.

   - kmem_cache_create() refactoring (Christian Brauner)

     Over the years have been growing new parameters to
     kmem_cache_create() where most of them are needed only for a small
     number of caches - most recently the rcu_freeptr_offset parameter.

     To avoid adding new parameters to kmem_cache_create() and adjusting
     all its callers, or creating new wrappers such as
     kmem_cache_create_rcu(), we can now pass extra parameters using the
     new struct kmem_cache_args. Not explicitly initialized fields
     default to values interpreted as unused.

     kmem_cache_create() is for now a wrapper that works both with the
     new form: kmem_cache_create(name, object_size, args, flags) and the
     legacy form: kmem_cache_create(name, object_size, align, flags,
     ctor)

   - kmem_cache_destroy() waits for kfree_rcu()'s in flight (Vlastimil
     Babka, Uladislau Rezki)

     Since SLOB removal, kfree() is allowed for freeing objects
     allocated by kmem_cache_create(). By extension kfree_rcu() as
     allowed as well, which can allow converting simple call_rcu()
     callbacks that only do kmem_cache_free(), as there was never a
     kmem_cache_free_rcu() variant. However, for caches that can be
     destroyed e.g. on module removal, the cache owners knew to issue
     rcu_barrier() first to wait for the pending call_rcu()'s, and this
     is not sufficient for pending kfree_rcu()'s due to its internal
     batching optimizations. Ulad has provided a new
     kvfree_rcu_barrier() and to make the usage less error-prone,
     kmem_cache_destroy() calls it. Additionally, destroying
     SLAB_TYPESAFE_BY_RCU caches now again issues rcu_barrier()
     synchronously instead of using an async work, because the past
     motivation for async work no longer applies. Users of custom
     call_rcu() callbacks should however keep calling rcu_barrier()
     before cache destruction.

   - Debugging use-after-free in SLAB_TYPESAFE_BY_RCU caches (Jann Horn)

     Currently, KASAN cannot catch UAFs in such caches as it is legal to
     access them within a grace period, and we only track the grace
     period when trying to free the underlying slab page. The new
     CONFIG_SLUB_RCU_DEBUG option changes the freeing of individual
     object to be RCU-delayed, after which KASAN can poison them.

   - Delayed memcg charging (Shakeel Butt)

     In some cases, the memcg is uknown at allocation time, such as
     receiving network packets in softirq context. With
     kmem_cache_charge() these may be now charged later when the user
     and its memcg is known.

   - Misc fixes and improvements (Pedro Falcato, Axel Rasmussen,
     Christoph Lameter, Yan Zhen, Peng Fan, Xavier)"

* tag 'slab-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (34 commits)
  mm, slab: restore kerneldoc for kmem_cache_create()
  io_uring: port to struct kmem_cache_args
  slab: make __kmem_cache_create() static inline
  slab: make kmem_cache_create_usercopy() static inline
  slab: remove kmem_cache_create_rcu()
  file: port to struct kmem_cache_args
  slab: create kmem_cache_create() compatibility layer
  slab: port KMEM_CACHE_USERCOPY() to struct kmem_cache_args
  slab: port KMEM_CACHE() to struct kmem_cache_args
  slab: remove rcu_freeptr_offset from struct kmem_cache
  slab: pass struct kmem_cache_args to do_kmem_cache_create()
  slab: pull kmem_cache_open() into do_kmem_cache_create()
  slab: pass struct kmem_cache_args to create_cache()
  slab: port kmem_cache_create_usercopy() to struct kmem_cache_args
  slab: port kmem_cache_create_rcu() to struct kmem_cache_args
  slab: port kmem_cache_create() to struct kmem_cache_args
  slab: add struct kmem_cache_args
  slab: s/__kmem_cache_create/do_kmem_cache_create/g
  memcg: add charging of already allocated slab objects
  mm/slab: Optimize the code logic in find_mergeable()
  ...
2024-09-18 08:53:53 +02:00
Linus Torvalds
3352633ce6 vfs-6.12.file
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Merge tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs file updates from Christian Brauner:
 "This is the work to cleanup and shrink struct file significantly.

  Right now, (focusing on x86) struct file is 232 bytes. After this
  series struct file will be 184 bytes aka 3 cacheline and a spare 8
  bytes for future extensions at the end of the struct.

  With struct file being as ubiquitous as it is this should make a
  difference for file heavy workloads and allow further optimizations in
  the future.

   - struct fown_struct was embedded into struct file letting it take up
     32 bytes in total when really it shouldn't even be embedded in
     struct file in the first place. Instead, actual users of struct
     fown_struct now allocate the struct on demand. This frees up 24
     bytes.

   - Move struct file_ra_state into the union containg the cleanup hooks
     and move f_iocb_flags out of the union. This closes a 4 byte hole
     we created earlier and brings struct file to 192 bytes. Which means
     struct file is 3 cachelines and we managed to shrink it by 40
     bytes.

   - Reorder struct file so that nothing crosses a cacheline.

     I suspect that in the future we will end up reordering some members
     to mitigate false sharing issues or just because someone does
     actually provide really good perf data.

   - Shrinking struct file to 192 bytes is only part of the work.

     Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache
     is created with SLAB_TYPESAFE_BY_RCU the free pointer must be
     located outside of the object because the cache doesn't know what
     part of the memory can safely be overwritten as it may be needed to
     prevent object recycling.

     That has the consequence that SLAB_TYPESAFE_BY_RCU may end up
     adding a new cacheline.

     So this also contains work to add a new kmem_cache_create_rcu()
     function that allows the caller to specify an offset where the
     freelist pointer is supposed to be placed. Thus avoiding the
     implicit addition of a fourth cacheline.

   - And finally this removes the f_version member in struct file.

     The f_version member isn't particularly well-defined. It is mainly
     used as a cookie to detect concurrent seeks when iterating
     directories. But it is also abused by some subsystems for
     completely unrelated things.

     It is mostly a directory and filesystem specific thing that doesn't
     really need to live in struct file and with its wonky semantics it
     really lacks a specific function.

     For pipes, f_version is (ab)used to defer poll notifications until
     a write has happened. And struct pipe_inode_info is used by
     multiple struct files in their ->private_data so there's no chance
     of pushing that down into file->private_data without introducing
     another pointer indirection.

     But pipes don't rely on f_pos_lock so this adds a union into struct
     file encompassing f_pos_lock and a pipe specific f_pipe member that
     pipes can use. This union of course can be extended to other file
     types and is similar to what we do in struct inode already"

* tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
  fs: remove f_version
  pipe: use f_pipe
  fs: add f_pipe
  ubifs: store cookie in private data
  ufs: store cookie in private data
  udf: store cookie in private data
  proc: store cookie in private data
  ocfs2: store cookie in private data
  input: remove f_version abuse
  ext4: store cookie in private data
  ext2: store cookie in private data
  affs: store cookie in private data
  fs: add generic_llseek_cookie()
  fs: use must_set_pos()
  fs: add must_set_pos()
  fs: add vfs_setpos_cookie()
  s390: remove unused f_version
  ceph: remove unused f_version
  adi: remove unused f_version
  mm: Removed @freeptr_offset to prevent doc warning
  ...
2024-09-16 09:14:02 +02:00
Vlastimil Babka
ecc4d6af97 Merge branch 'slab/for-6.12/kmem_cache_args' into slab/for-next
Merge kmem_cache_create() refactoring by Christian Brauner.

Note this includes a merge of the vfs.file tree that contains the
prerequisity kmem_cache_create_rcu() work.
2024-09-13 11:13:03 +02:00
Vlastimil Babka
a715e94dbd Merge branch 'slab/for-6.12/rcu_barriers' into slab/for-next
Merge most of SLUB feature work for 6.12:

- Barrier for pending kfree_rcu() in kmem_cache_destroy() and associated
  refactoring of the destroy path (Vlastimil Babka)
- CONFIG_SLUB_RCU_DEBUG to allow KASAN catching UAF bugs in
  SLAB_TYPESAFE_BY_RCU caches (Jann Horn)
- kmem_cache_charge() for delayed kmemcg charging (Shakeel Butt)
2024-09-13 11:08:27 +02:00
Christian Brauner
dacf472bcd slab: remove rcu_freeptr_offset from struct kmem_cache
Pass down struct kmem_cache_args to calculate_sizes() so we can use
args->{use}_freeptr_offset directly. This allows us to remove
->rcu_freeptr_offset from struct kmem_cache.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
3dbe2bad57 slab: pass struct kmem_cache_args to do_kmem_cache_create()
and initialize most things in do_kmem_cache_create(). In a follow-up
patch we'll remove rcu_freeptr_offset from struct kmem_cache.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
fc0eac57d0 slab: pull kmem_cache_open() into do_kmem_cache_create()
do_kmem_cache_create() is the only caller and we're going to pass down
struct kmem_cache_args in a follow-up patch.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
53d3d21086 slab: s/__kmem_cache_create/do_kmem_cache_create/g
Free up reusing the double-underscore variant for follow-up patches.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:57 +02:00
Shakeel Butt
9028cdeb38 memcg: add charging of already allocated slab objects
At the moment, the slab objects are charged to the memcg at the
allocation time. However there are cases where slab objects are
allocated at the time where the right target memcg to charge it to is
not known. One such case is the network sockets for the incoming
connection which are allocated in the softirq context.

Couple hundred thousand connections are very normal on large loaded
server and almost all of those sockets underlying those connections get
allocated in the softirq context and thus not charged to any memcg.
However later at the accept() time we know the right target memcg to
charge. Let's add new API to charge already allocated objects, so we can
have better accounting of the memory usage.

To measure the performance impact of this change, tcp_crr is used from
the neper [1] performance suite. Basically it is a network ping pong
test with new connection for each ping pong.

The server and the client are run inside 3 level of cgroup hierarchy
using the following commands:

Server:
 $ tcp_crr -6

Client:
 $ tcp_crr -6 -c -H ${server_ip}

If the client and server run on different machines with 50 GBPS NIC,
there is no visible impact of the change.

For the same machine experiment with v6.11-rc5 as base.

          base (throughput)     with-patch
tcp_crr   14545 (+- 80)         14463 (+- 56)

It seems like the performance impact is within the noise.

Link: https://github.com/google/neper [1]
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com> # net
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:33:41 +02:00
Peng Fan
59090e479a mm, slub: avoid zeroing kmalloc redzone
Since commit 946fa0dbf2 ("mm/slub: extend redzone check to extra
allocated kmalloc space than requested"), setting orig_size treats
the wasted space (object_size - orig_size) as a redzone. However with
init_on_free=1 we clear the full object->size, including the redzone.

Additionally we clear the object metadata, including the stored orig_size,
making it zero, which makes check_object() treat the whole object as a
redzone.

These issues lead to the following BUG report with "slub_debug=FUZ
init_on_free=1":

[    0.000000] =============================================================================
[    0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten
[    0.000000] -----------------------------------------------------------------------------
[    0.000000]
[    0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc
[    0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc
[    0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff)
[    0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8
[    0.000000]
[    0.000000] Redzone  ffff000010032850: cc cc cc cc cc cc cc cc                          ........
[    0.000000] Object   ffff000010032858: cc cc cc cc cc cc cc cc                          ........
[    0.000000] Redzone  ffff000010032860: cc cc cc cc cc cc cc cc                          ........
[    0.000000] Padding  ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00              ............
[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144
[    0.000000] Hardware name: NXP i.MX95 19X19 board (DT)
[    0.000000] Call trace:
[    0.000000]  dump_backtrace+0x90/0xe8
[    0.000000]  show_stack+0x18/0x24
[    0.000000]  dump_stack_lvl+0x74/0x8c
[    0.000000]  dump_stack+0x18/0x24
[    0.000000]  print_trailer+0x150/0x218
[    0.000000]  check_object+0xe4/0x454
[    0.000000]  free_to_partial_list+0x2f8/0x5ec

To address the issue, use orig_size to clear the used area. And restore
the value of orig_size after clear the remaining area.

When CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns
s->object_size. So when using memset to init the area, the size can simply
be orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not
enabled. And orig_size can never be bigger than object_size.

Fixes: 946fa0dbf2 ("mm/slub: extend redzone check to extra allocated kmalloc space than requested")
Cc: <stable@vger.kernel.org>
Reviewed-by: Feng Tang <feng.tang@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-03 07:33:27 +02:00
Hao Ge
ab7ca09520 mm/slub: add check for s->flags in the alloc_tagging_slab_free_hook
When enable CONFIG_MEMCG & CONFIG_KFENCE & CONFIG_KMEMLEAK, the following
warning always occurs,This is because the following call stack occurred:
mem_pool_alloc
    kmem_cache_alloc_noprof
        slab_alloc_node
            kfence_alloc

Once the kfence allocation is successful,slab->obj_exts will not be empty,
because it has already been assigned a value in kfence_init_pool.

Since in the prepare_slab_obj_exts_hook function,we perform a check for
s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE),the alloc_tag_add function
will not be called as a result.Therefore,ref->ct remains NULL.

However,when we call mem_pool_free,since obj_ext is not empty, it
eventually leads to the alloc_tag_sub scenario being invoked.  This is
where the warning occurs.

So we should add corresponding checks in the alloc_tagging_slab_free_hook.
For __GFP_NO_OBJ_EXT case,I didn't see the specific case where it's using
kfence,so I won't add the corresponding check in
alloc_tagging_slab_free_hook for now.

[    3.734349] ------------[ cut here ]------------
[    3.734807] alloc_tag was not set
[    3.735129] WARNING: CPU: 4 PID: 40 at ./include/linux/alloc_tag.h:130 kmem_cache_free+0x444/0x574
[    3.735866] Modules linked in: autofs4
[    3.736211] CPU: 4 UID: 0 PID: 40 Comm: ksoftirqd/4 Tainted: G        W          6.11.0-rc3-dirty #1
[    3.736969] Tainted: [W]=WARN
[    3.737258] Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
[    3.737875] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    3.738501] pc : kmem_cache_free+0x444/0x574
[    3.738951] lr : kmem_cache_free+0x444/0x574
[    3.739361] sp : ffff80008357bb60
[    3.739693] x29: ffff80008357bb70 x28: 0000000000000000 x27: 0000000000000000
[    3.740338] x26: ffff80008207f000 x25: ffff000b2eb2fd60 x24: ffff0000c0005700
[    3.740982] x23: ffff8000804229e4 x22: ffff800082080000 x21: ffff800081756000
[    3.741630] x20: fffffd7ff8253360 x19: 00000000000000a8 x18: ffffffffffffffff
[    3.742274] x17: ffff800ab327f000 x16: ffff800083398000 x15: ffff800081756df0
[    3.742919] x14: 0000000000000000 x13: 205d344320202020 x12: 5b5d373038343337
[    3.743560] x11: ffff80008357b650 x10: 000000000000005d x9 : 00000000ffffffd0
[    3.744231] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008237bad0 x6 : c0000000ffff7fff
[    3.744907] x5 : ffff80008237ba78 x4 : ffff8000820bbad0 x3 : 0000000000000001
[    3.745580] x2 : 68d66547c09f7800 x1 : 68d66547c09f7800 x0 : 0000000000000000
[    3.746255] Call trace:
[    3.746530]  kmem_cache_free+0x444/0x574
[    3.746931]  mem_pool_free+0x44/0xf4
[    3.747306]  free_object_rcu+0xc8/0xdc
[    3.747693]  rcu_do_batch+0x234/0x8a4
[    3.748075]  rcu_core+0x230/0x3e4
[    3.748424]  rcu_core_si+0x14/0x1c
[    3.748780]  handle_softirqs+0x134/0x378
[    3.749189]  run_ksoftirqd+0x70/0x9c
[    3.749560]  smpboot_thread_fn+0x148/0x22c
[    3.749978]  kthread+0x10c/0x118
[    3.750323]  ret_from_fork+0x10/0x20
[    3.750696] ---[ end trace 0000000000000000 ]---

Link: https://lkml.kernel.org/r/20240816013336.17505-1-hao.ge@linux.dev
Fixes: 4b87369646 ("mm/slab: add allocation accounting into slab allocation and free paths")
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 17:59:01 -07:00
Christian Brauner
d345bd2e98 mm: add kmem_cache_create_rcu()
When a kmem cache is created with SLAB_TYPESAFE_BY_RCU the free pointer
must be located outside of the object because we don't know what part of
the memory can safely be overwritten as it may be needed to prevent
object recycling.

That has the consequence that SLAB_TYPESAFE_BY_RCU may end up adding a
new cacheline. This is the case for e.g., struct file. After having it
shrunk down by 40 bytes and having it fit in three cachelines we still
have SLAB_TYPESAFE_BY_RCU adding a fourth cacheline because it needs to
accommodate the free pointer.

Add a new kmem_cache_create_rcu() function that allows the caller to
specify an offset where the free pointer is supposed to be placed.

Link: https://lore.kernel.org/r/20240828-work-kmem_cache-rcu-v3-2-5460bc1f09f6@kernel.org
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-29 15:20:32 +02:00
Jann Horn
b8c8ba73c6 slub: Introduce CONFIG_SLUB_RCU_DEBUG
Currently, KASAN is unable to catch use-after-free in SLAB_TYPESAFE_BY_RCU
slabs because use-after-free is allowed within the RCU grace period by
design.

Add a SLUB debugging feature which RCU-delays every individual
kmem_cache_free() before either actually freeing the object or handing it
off to KASAN, and change KASAN to poison freed objects as normal when this
option is enabled.

For now I've configured Kconfig.debug to default-enable this feature in the
KASAN GENERIC and SW_TAGS modes; I'm not enabling it by default in HW_TAGS
mode because I'm not sure if it might have unwanted performance degradation
effects there.

Note that this is mostly useful with KASAN in the quarantine-based GENERIC
mode; SLAB_TYPESAFE_BY_RCU slabs are basically always also slabs with a
->ctor, and KASAN's assign_tag() currently has to assign fixed tags for
those, reducing the effectiveness of SW_TAGS/HW_TAGS mode.
(A possible future extension of this work would be to also let SLUB call
the ->ctor() on every allocation instead of only when the slab page is
allocated; then tag-based modes would be able to assign new tags on every
reallocation.)

Tested-by: syzbot+263726e59eab6b442723@syzkaller.appspotmail.com
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz> #slab
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:51 +02:00
Jann Horn
b3c3424575 kasan: catch invalid free before SLUB reinitializes the object
Currently, when KASAN is combined with init-on-free behavior, the
initialization happens before KASAN's "invalid free" checks.

More importantly, a subsequent commit will want to RCU-delay the actual
SLUB freeing of an object, and we'd like KASAN to still validate
synchronously that freeing the object is permitted. (Otherwise this
change will make the existing testcase kmem_cache_invalid_free fail.)

So add a new KASAN hook that allows KASAN to pre-validate a
kmem_cache_free() operation before SLUB actually starts modifying the
object or its metadata.

Inside KASAN, this:

 - moves checks from poison_slab_object() into check_slab_allocation()
 - moves kasan_arch_is_ready() up into callers of poison_slab_object()
 - removes "ip" argument of poison_slab_object() and __kasan_slab_free()
   (since those functions no longer do any reporting)

Acked-by: Vlastimil Babka <vbabka@suse.cz> #slub
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:51 +02:00
Christoph Lameter
1941b31482 Reenable NUMA policy support in the slab allocator
Revert commit 8014c46ad9 ("slub: use alloc_pages_node() in alloc_slab_page()").

The patch disabled the numa policy support in the slab allocator. It
did not consider that alloc_pages() uses memory policies but
alloc_pages_node() does not.

As a result of this patch slab memory allocations are no longer spread via
interleave policy across all available NUMA nodes on bootup. Instead
all slab memory is allocated close to the boot processor. This leads to
an imbalance of memory accesses on NUMA systems.

Also applications using MPOL_INTERLEAVE as a memory policy will no longer
spread slab allocations over all nodes in the interleave set but allocate
memory locally. This may also result in unbalanced allocations
on a single numa node.

SLUB does not apply memory policies to individual object allocations.
However, it relies on the page allocators support of memory policies
through alloc_pages() to do the NUMA memory allocations on a per
folio or page level. SLUB also applies memory policies when retrieving
partial allocated slab pages from the partial list.

Fixes: 8014c46ad9 ("slub: use alloc_pages_node() in alloc_slab_page()")
Signed-off-by: Christoph Lameter <cl@gentwo.org>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-26 21:42:57 +02:00
Axel Rasmussen
bf6b9e9ba0 mm, slub: print CPU id (and its node) on slab OOM
Depending on how remote_node_defrag_ratio is configured, allocations can
end up in this path as a result of the local node being OOM, despite the
allocation overall being unconstrained (node == -1).

When we print a warning, printing the current CPU makes that situation
more clear (i.e., you can immediately see which node's OOM status
matters for the allocation at hand).

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-26 21:19:54 +02:00
Rik van Riel
a371d558e6 mm, slub: do not call do_slab_free for kfence object
In 782f8906f8 the freeing of kfence objects was moved from deep
inside do_slab_free to the wrapper functions outside. This is a nice
change, but unfortunately it missed one spot in __kmem_cache_free_bulk.

This results in a crash like this:

BUG skbuff_head_cache (Tainted: G S  B       E     ): Padding overwritten. 0xffff88907fea0f00-0xffff88907fea0fff @offset=3840

slab_err (mm/slub.c:1129)
free_to_partial_list (mm/slub.c:? mm/slub.c:4036)
slab_pad_check (mm/slub.c:864 mm/slub.c:1290)
check_slab (mm/slub.c:?)
free_to_partial_list (mm/slub.c:3171 mm/slub.c:4036)
kmem_cache_alloc_bulk (mm/slub.c:? mm/slub.c:4495 mm/slub.c:4586 mm/slub.c:4635)
napi_build_skb (net/core/skbuff.c:348 net/core/skbuff.c:527 net/core/skbuff.c:549)

All the other callers to do_slab_free appear to be ok.

Add a kfence_free check in __kmem_cache_free_bulk to avoid the crash.

Reported-by: Chris Mason <clm@meta.com>
Fixes: 782f8906f8 ("mm/slub: free KFENCE objects in slab_free_hook()")
Cc: stable@kernel.org
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-07-30 11:50:00 +02:00
Linus Torvalds
fbc90c042c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN
walkers") is known to cause a performance regression
   (https://lore.kernel.org/all/3acefad9-96e5-4681-8014-827d6be71c7a@linux.ibm.com/T/#mfa809800a7862fb5bdf834c6f71a3a5113eb83ff).
   Yu has a fix which I'll send along later via the hotfixes branch.
 
 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.
 
 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that.  This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches.  My bad.
 
 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"
 
 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability of
   cgroup writeback"
 
 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache index".
 
 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of the
   zeropage in MAP_SHARED mappings.  I don't see any runtime effects here -
   more a cleanup/understandability/maintainablity thing.
 
 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of
   higher addresses, for aarch64.  The (poorly named) series is
   "Restructure va_high_addr_switch".
 
 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".
 
 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the
   series "Enhance soft hwpoison handling and injection".
 
 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything.  Some landed in this pull.
 
 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has
   simplified migration's use of hardware-offload memory copying.
 
 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".
 
 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code.  This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.
 
 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.
 
 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP.  By default this
   is a no-op - users must opt in vis sysfs controls.  Dramatic
   improvements in pagefault latency are realized.
 
 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".
 
 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".
 
 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".
 
 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".
 
 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances.  A 10x speedup is seen in a microbenchmark.
 
   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.
 
 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".
 
 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.
 
 - Is anyone reading this stuff?  If so, email me!
 
 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.
 
 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".
 
 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.
 
 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".
 
 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE".  It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.
 
 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.
 
 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large folio
   userspace copying.
 
 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers.  From SeongJae Park.
 
 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.
 
 - David Hildenbrand sends along more cleanups, this time against the
   migration code.  The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".
 
 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code.  He addresses this in the series "mm: Fix various
   readahead quirks".
 
 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's self
   testing code.
 
 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code.  The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this.  The series is marked cc:stable.
 
 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.
 
 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion.  The series (which also makes the memcg-v1 code
   Kconfigurable) are
 
   "mm: memcg: separate legacy cgroup v1 code and put under config
   option" and
   "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1"
 
 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.
 
 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of excessive
   correctable memory errors.  In order to permit userspace to monitor and
   handle this situation.
 
 - Kefeng Wang's series "mm: migrate: support poison recover from migrate
   folio" teaches the kernel to appropriately handle migration from
   poisoned source folios rather than simply panicing.
 
 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.
 
 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory utilization.
 
 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare
   refcount increments.  So these paes can first be moved aside if they
   reside in the movable zone or a CMA block.
 
 - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps
   for much faster reading of vma information.  The series is "query VMAs
   from /proc/<pid>/maps".
 
 - In the series "mm: introduce per-order mTHP split counters" Lance Yang
   improves the kernel's presentation of developer information related to
   multisize THP splitting.
 
 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)".  This permits
   userspace to use all available huge page sizes.
 
 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and not
   very useful feature from slab fault injection.
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Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Vlastimil Babka
a7526fe8b9 mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
Patch series "revert unconditional slab and page allocator fault injection
calls".

These two patches largely revert commits that added function call overhead
into slab and page allocation hotpaths and that cannot be currently
disabled even though related CONFIG_ options do exist.

A much more involved solution that can keep the callsites always existing
but hidden behind a static key if unused, is possible [1] and can be
pursued by anyone who believes it's necessary.  Meanwhile the fact the
should_failslab() error injection is already not functional on kernels
built with current gcc without anyone noticing [2], and lukewarm response
to [1] suggests the need is not there.  I believe it will be more fair to
have the state after this series as a baseline for possible further
optimisation, instead of the unconditional overhead.

For example a possible compromise for anyone who's fine with an empty
function call overhead but not the full CONFIG_FAILSLAB /
CONFIG_FAIL_PAGE_ALLOC overhead is to reuse patch 1 from [1] but insert a
static key check only inside should_failslab() and
should_fail_alloc_page() before performing the more expensive checks.

[1] https://lore.kernel.org/all/20240620-fault-injection-statickeys-v2-0-e23947d3d84b@suse.cz/#t
[2] https://github.com/bpftrace/bpftrace/issues/3258


This patch (of 2):

This mostly reverts commit 4f6923fbb3 ("mm: make should_failslab always
available for fault injection").  The commit made should_failslab() a
noinline function that's always called from the slab allocation hotpath,
even if it's empty because CONFIG_SHOULD_FAILSLAB is not enabled, and
there is no option to disable that call.  This is visible in profiles and
the function call overhead can be noticeable especially with cpu
mitigations.

Meanwhile the bpftrace program example in the commit silently does not
work without CONFIG_SHOULD_FAILSLAB anyway with a recent gcc, because the
empty function gets a .constprop clone that is actually being called
(uselessly) from the slab hotpath, while the error injection is hooked to
the original function that's not being called at all [1].

Thus put the whole should_failslab() function back behind
CONFIG_SHOULD_FAILSLAB.  It's not a complete revert of 4f6923fbb3 - the
int return type that returns -ENOMEM on failure is preserved, as well
ALLOW_ERROR_INJECTION annotation.  The BTF_ID() record that was meanwhile
added is also guarded by CONFIG_SHOULD_FAILSLAB.

[1] https://github.com/bpftrace/bpftrace/issues/3258

Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-0-9e2651945d68@suse.cz
Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-1-9e2651945d68@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17 21:05:18 -07:00
Vlastimil Babka
436381eaf2 Merge branch 'slab/for-6.11/buckets' into slab/for-next
Merge all the slab patches previously collected on top of v6.10-rc1,
over cleanups/fixes that had to be based on rc6.
2024-07-15 10:44:16 +02:00
Suren Baghdasaryan
7b1fdf2ba4 mm, slab: move prepare_slab_obj_exts_hook under CONFIG_MEM_ALLOC_PROFILING
The only place prepare_slab_obj_exts_hook() is currently being used is
from alloc_tagging_slab_alloc_hook() when CONFIG_MEM_ALLOC_PROFILING=y.
Move its definition under CONFIG_MEM_ALLOC_PROFILING to prevent unused
function warning for CONFIG_SLAB_OBJ_EXT=n case.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407050845.zNONqauD-lkp@intel.com/
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Xiongwei Song <xiongwei.song@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-07-11 19:14:03 +02:00
Johannes Weiner
3a3b7fec39 mm: remove CONFIG_MEMCG_KMEM
CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab
tracking is enabled.  It has been default-enabled and equivalent to
CONFIG_MEMCG for almost a decade.  We've only grown more kernel memory
accounting sites since, and there is no imaginable cgroup usecase going
forward that wants to track user pages but not the multitude of
user-drivable kernel allocations.

Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10 12:14:54 -07:00
Suren Baghdasaryan
302a3ea38a mm, slab: move allocation tagging code in the alloc path into a hook
Move allocation tagging specific code in the allocation path into
alloc_tagging_slab_alloc_hook, similar to how freeing path uses
alloc_tagging_slab_free_hook. No functional changes, just code
cleanup.

Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-07-04 16:14:38 +02:00
Ilya Leoshkevich
adea987618 mm: slub: disable KMSAN when checking the padding bytes
Even though the KMSAN warnings generated by memchr_inv() are suppressed by
metadata_access_enable(), its return value may still be poisoned.

The reason is that the last iteration of memchr_inv() returns `*start !=
value ?  start : NULL`, where *start is poisoned.  Because of this,
somewhat counterintuitively, the shadow value computed by
visitSelectInst() is equal to `(uintptr_t)start`.

One possibility to fix this, since the intention behind guarding
memchr_inv() behind metadata_access_enable() is to touch poisoned metadata
without triggering KMSAN, is to unpoison its return value.  However, this
approach is too fragile.  So simply disable the KMSAN checks in the
respective functions.

Link: https://lkml.kernel.org/r/20240621113706.315500-19-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:23 -07:00
Ilya Leoshkevich
0e9a8550f3 mm: slub: let KMSAN access metadata
Building the kernel with CONFIG_SLUB_DEBUG and CONFIG_KMSAN causes KMSAN
to complain about touching redzones in kfree().

Fix by extending the existing KASAN-related metadata_access_enable() and
metadata_access_disable() functions to KMSAN.

Link: https://lkml.kernel.org/r/20240621113706.315500-18-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:23 -07:00
Ilya Leoshkevich
f416817197 kmsan: support SLAB_POISON
Avoid false KMSAN negatives with SLUB_DEBUG by allowing kmsan_slab_free()
to poison the freed memory, and by preventing init_object() from
unpoisoning new allocations by using __memset().

There are two alternatives to this approach.  First, init_object() can be
marked with __no_sanitize_memory.  This annotation should be used with
great care, because it drops all instrumentation from the function, and
any shadow writes will be lost.  Even though this is not a concern with
the current init_object() implementation, this may change in the future.

Second, kmsan_poison_memory() calls may be added after memset() calls. 
The downside is that init_object() is called from free_debug_processing(),
in which case poisoning will erase the distinction between simply
uninitialized memory and UAF.

Link: https://lkml.kernel.org/r/20240621113706.315500-14-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:22 -07:00
Kees Cook
67f2df3b82 mm/slab: Plumb kmem_buckets into __do_kmalloc_node()
Introduce CONFIG_SLAB_BUCKETS which provides the infrastructure to
support separated kmalloc buckets (in the following kmem_buckets_create()
patches and future codetag-based separation). Since this will provide
a mitigation for a very common case of exploits, it is recommended to
enable this feature for general purpose distros. By default, the new
Kconfig will be enabled if CONFIG_SLAB_FREELIST_HARDENED is enabled (and
it is added to the hardening.config Kconfig fragment).

To be able to choose which buckets to allocate from, make the buckets
available to the internal kmalloc interfaces by adding them as the
second argument, rather than depending on the buckets being chosen from
the fixed set of global buckets. Where the bucket is not available,
pass NULL, which means "use the default system kmalloc bucket set"
(the prior existing behavior), as implemented in kmalloc_slab().

To avoid adding the extra argument when !CONFIG_SLAB_BUCKETS, only the
top-level macros and static inlines use the buckets argument (where
they are stripped out and compiled out respectively). The actual extern
functions can then be built without the argument, and the internals
fall back to the global kmalloc buckets unconditionally.

Co-developed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-07-03 12:24:19 +02:00
Suren Baghdasaryan
b4601d096a mm/slab: fix 'variable obj_exts set but not used' warning
slab_post_alloc_hook() uses prepare_slab_obj_exts_hook() to obtain
slabobj_ext object.  Currently the only user of slabobj_ext object in this
path is memory allocation profiling, therefore when it's not enabled this
object is not needed.  This also generates a warning when compiling with
CONFIG_MEM_ALLOC_PROFILING=n.  Move the code under this configuration to
fix the warning.  If more slabobj_ext users appear in the future, the code
will have to be changed back to call prepare_slab_obj_exts_hook().

Link: https://lkml.kernel.org/r/20240614225951.3845577-1-surenb@google.com
Fixes: 4b87369646 ("mm/slab: add allocation accounting into slab allocation and free paths")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406150444.F6neSaiy-lkp@intel.com/
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24 20:52:09 -07:00
Chengming Zhou
4a24bbabc8 slab: delete useless RED_INACTIVE and RED_ACTIVE
These seem useless since we use the SLUB_RED_INACTIVE and SLUB_RED_ACTIVE,
so just delete them, no functional change.

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Christoph Lameter (Ampere) <cl@linux.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-06-24 21:41:41 +02:00
Chengming Zhou
adef2aeaa2 slab: don't put freepointer outside of object if only orig_size
The commit 946fa0dbf2 ("mm/slub: extend redzone check to extra
allocated kmalloc space than requested") will extend right redzone
when allocating for orig_size < object_size. So we can't overlay the
freepointer in the object space in this case.

But the code looks like it forgot to check SLAB_RED_ZONE, since there
won't be extended right redzone if only orig_size enabled.

As we are here, make this complex conditional expressions a little
prettier and add some comments about extending right redzone when
slub_debug_orig_size() enabled.

Reviewed-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-06-07 11:03:24 +02:00
Chengming Zhou
47d911b02c slab: make check_object() more consistent
Now check_object() calls check_bytes_and_report() multiple times to
check every section of the object it cares about, like left and right
redzones, object poison, paddings poison and freepointer. It will
abort the checking process and return 0 once it finds an error.

There are two inconsistencies in check_object(), which are alignment
padding checking and object padding checking. We only print the error
messages but don't return 0 to tell callers that something is wrong
and needs to be handled. Please see alloc_debug_processing() and
free_debug_processing() for details.

We want to do all checks without skipping, so use a local variable
"ret" to save each check result and change check_bytes_and_report() to
only report specific error findings. Then at end of check_object(),
print the trailer once if any found an error.

Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-06-07 11:03:24 +02:00
Thadeu Lima de Souza Cascardo
3f0c44c8c2 codetag: avoid race at alloc_slab_obj_exts
When CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled, the following warning
may be noticed:

[   48.299584] ------------[ cut here ]------------
[   48.300092] alloc_tag was not set
[   48.300528] WARNING: CPU: 2 PID: 1361 at include/linux/alloc_tag.h:130 alloc_tagging_slab_free_hook+0x84/0xc7
[   48.301305] Modules linked in:
[   48.301553] CPU: 2 PID: 1361 Comm: systemd-udevd Not tainted 6.10.0-rc1-00003-gac8755535862 #176
[   48.302196] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[   48.302752] RIP: 0010:alloc_tagging_slab_free_hook+0x84/0xc7
[   48.303169] Code: 8d 1c c4 48 85 db 74 4d 48 83 3b 00 75 1e 80 3d 65 02 86 04 00 75 15 48 c7 c7 11 48 1d 85 c6 05 55 02 86 04 01 e8 64 44 a5 ff <0f> 0b 48 8b 03 48 85 c0 74 21 48 83 f8 01 74 14 48 8b 50 20 48 f7
[   48.304411] RSP: 0018:ffff8880111b7d40 EFLAGS: 00010282
[   48.304916] RAX: 0000000000000000 RBX: ffff88800fcc9008 RCX: 0000000000000000
[   48.305455] RDX: 0000000080000000 RSI: ffff888014060000 RDI: ffffed1002236f97
[   48.305979] RBP: 0000000000001100 R08: fffffbfff0aa73a1 R09: 0000000000000000
[   48.306473] R10: ffffffff814515e5 R11: 0000000000000003 R12: ffff88800fcc9000
[   48.306943] R13: ffff88800b2e5cc0 R14: ffff8880111b7d90 R15: 0000000000000000
[   48.307529] FS:  00007faf5d1908c0(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
[   48.308223] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   48.308710] CR2: 000058fb220c9118 CR3: 00000000110cc000 CR4: 0000000000750ef0
[   48.309274] PKRU: 55555554
[   48.309804] Call Trace:
[   48.310029]  <TASK>
[   48.310290]  ? show_regs+0x84/0x8d
[   48.310722]  ? alloc_tagging_slab_free_hook+0x84/0xc7
[   48.311298]  ? __warn+0x13b/0x2ff
[   48.311580]  ? alloc_tagging_slab_free_hook+0x84/0xc7
[   48.311987]  ? report_bug+0x2ce/0x3ab
[   48.312292]  ? handle_bug+0x8c/0x107
[   48.312563]  ? exc_invalid_op+0x34/0x6f
[   48.312842]  ? asm_exc_invalid_op+0x1a/0x20
[   48.313173]  ? this_cpu_in_panic+0x1c/0x72
[   48.313503]  ? alloc_tagging_slab_free_hook+0x84/0xc7
[   48.313880]  ? putname+0x143/0x14e
[   48.314152]  kmem_cache_free+0xe9/0x214
[   48.314454]  putname+0x143/0x14e
[   48.314712]  do_unlinkat+0x413/0x45e
[   48.315001]  ? __pfx_do_unlinkat+0x10/0x10
[   48.315388]  ? __check_object_size+0x4d7/0x525
[   48.315744]  ? __sanitizer_cov_trace_pc+0x20/0x4a
[   48.316167]  ? __sanitizer_cov_trace_pc+0x20/0x4a
[   48.316757]  ? getname_flags+0x4ed/0x500
[   48.317261]  __x64_sys_unlink+0x42/0x4a
[   48.317741]  do_syscall_64+0xe2/0x149
[   48.318171]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   48.318602] RIP: 0033:0x7faf5d8850ab
[   48.318891] Code: fd ff ff e8 27 dd 01 00 0f 1f 80 00 00 00 00 f3 0f 1e fa b8 5f 00 00 00 0f 05 c3 0f 1f 40 00 f3 0f 1e fa b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 41 2d 0e 00 f7 d8
[   48.320649] RSP: 002b:00007ffc44982b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
[   48.321182] RAX: ffffffffffffffda RBX: 00005ba344a44680 RCX: 00007faf5d8850ab
[   48.321667] RDX: 0000000000000000 RSI: 00005ba344a44430 RDI: 00007ffc44982b40
[   48.322139] RBP: 00007ffc44982c00 R08: 0000000000000000 R09: 0000000000000007
[   48.322598] R10: 00005ba344a44430 R11: 0000000000000246 R12: 0000000000000000
[   48.323071] R13: 00007ffc44982b40 R14: 0000000000000000 R15: 0000000000000000
[   48.323596]  </TASK>

This is due to a race when two objects are allocated from the same slab,
which did not have an obj_exts allocated for.

In such a case, the two threads will notice the NULL obj_exts and after
one assigns slab->obj_exts, the second one will happily do the exchange if
it reads this new assigned value.

In order to avoid that, verify that the read obj_exts does not point to an
allocated obj_exts before doing the exchange.

Link: https://lkml.kernel.org/r/20240527183007.1595037-1-cascardo@igalia.com
Fixes: 09c46563ff ("codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocations")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 19:19:26 -07:00
Matthew Wilcox (Oracle)
4d2bcefa96 mm: Reduce the number of slab->folio casts
Mark a few more folio functions as taking a const folio pointer, which
allows us to remove a few places in slab which cast away the const.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-31 15:51:10 +02:00
Vlastimil Babka
a0a44d9175 mm, slab: don't wrap internal functions with alloc_hooks()
The functions __kmalloc_noprof(), kmalloc_large_noprof(),
kmalloc_trace_noprof() and their _node variants are all internal to the
implementations of kmalloc_noprof() and kmalloc_node_noprof() and are
only declared in the "public" slab.h and exported so that those
implementations can be static inline and distinguish the build-time
constant size variants. The only other users for some of the internal
functions are slub_kunit and fortify_kunit tests which make very
short-lived allocations.

Therefore we can stop wrapping them with the alloc_hooks() macro.
Instead add a __ prefix to all of them and a comment documenting these
as internal. Also rename __kmalloc_trace() to __kmalloc_cache() which is
more descriptive - it is a variant of __kmalloc() where the exact
kmalloc cache has been already determined.

The usage in fortify_kunit can be removed completely, as the internal
functions should be tested already through kmalloc() tests in the
test variant that passes non-constant allocation size.

Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-28 09:27:50 +02:00
Linus Torvalds
61307b7be4 The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.  Notable
 series include:
 
 - Lucas Stach has provided some page-mapping
   cleanup/consolidation/maintainability work in the series "mm/treewide:
   Remove pXd_huge() API".
 
 - In the series "Allow migrate on protnone reference with
   MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
   MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one
   test.
 
 - In their series "Memory allocation profiling" Kent Overstreet and
   Suren Baghdasaryan have contributed a means of determining (via
   /proc/allocinfo) whereabouts in the kernel memory is being allocated:
   number of calls and amount of memory.
 
 - Matthew Wilcox has provided the series "Various significant MM
   patches" which does a number of rather unrelated things, but in largely
   similar code sites.
 
 - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes
   Weiner has fixed the page allocator's handling of migratetype requests,
   with resulting improvements in compaction efficiency.
 
 - In the series "make the hugetlb migration strategy consistent" Baolin
   Wang has fixed a hugetlb migration issue, which should improve hugetlb
   allocation reliability.
 
 - Liu Shixin has hit an I/O meltdown caused by readahead in a
   memory-tight memcg.  Addressed in the series "Fix I/O high when memory
   almost met memcg limit".
 
 - In the series "mm/filemap: optimize folio adding and splitting" Kairui
   Song has optimized pagecache insertion, yielding ~10% performance
   improvement in one test.
 
 - Baoquan He has cleaned up and consolidated the early zone
   initialization code in the series "mm/mm_init.c: refactor
   free_area_init_core()".
 
 - Baoquan has also redone some MM initializatio code in the series
   "mm/init: minor clean up and improvement".
 
 - MM helper cleanups from Christoph Hellwig in his series "remove
   follow_pfn".
 
 - More cleanups from Matthew Wilcox in the series "Various page->flags
   cleanups".
 
 - Vlastimil Babka has contributed maintainability improvements in the
   series "memcg_kmem hooks refactoring".
 
 - More folio conversions and cleanups in Matthew Wilcox's series
 
 	"Convert huge_zero_page to huge_zero_folio"
 	"khugepaged folio conversions"
 	"Remove page_idle and page_young wrappers"
 	"Use folio APIs in procfs"
 	"Clean up __folio_put()"
 	"Some cleanups for memory-failure"
 	"Remove page_mapping()"
 	"More folio compat code removal"
 
 - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb
   functions to work on folis".
 
 - Code consolidation and cleanup work related to GUP's handling of
   hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
 
 - Rick Edgecombe has developed some fixes to stack guard gaps in the
   series "Cover a guard gap corner case".
 
 - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series
   "mm/ksm: fix ksm exec support for prctl".
 
 - Baolin Wang has implemented NUMA balancing for multi-size THPs.  This
   is a simple first-cut implementation for now.  The series is "support
   multi-size THP numa balancing".
 
 - Cleanups to vma handling helper functions from Matthew Wilcox in the
   series "Unify vma_address and vma_pgoff_address".
 
 - Some selftests maintenance work from Dev Jain in the series
   "selftests/mm: mremap_test: Optimizations and style fixes".
 
 - Improvements to the swapping of multi-size THPs from Ryan Roberts in
   the series "Swap-out mTHP without splitting".
 
 - Kefeng Wang has significantly optimized the handling of arm64's
   permission page faults in the series
 
 	"arch/mm/fault: accelerate pagefault when badaccess"
 	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
 
 - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it
   GUP-fast".
 
 - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to
   use struct vm_fault".
 
 - selftests build fixes from John Hubbard in the series "Fix
   selftests/mm build without requiring "make headers"".
 
 - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
   series "Improved Memory Tier Creation for CPUless NUMA Nodes".  Fixes
   the initialization code so that migration between different memory types
   works as intended.
 
 - David Hildenbrand has improved follow_pte() and fixed an errant driver
   in the series "mm: follow_pte() improvements and acrn follow_pte()
   fixes".
 
 - David also did some cleanup work on large folio mapcounts in his
   series "mm: mapcount for large folios + page_mapcount() cleanups".
 
 - Folio conversions in KSM in Alex Shi's series "transfer page to folio
   in KSM".
 
 - Barry Song has added some sysfs stats for monitoring multi-size THP's
   in the series "mm: add per-order mTHP alloc and swpout counters".
 
 - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled
   and limit checking cleanups".
 
 - Matthew Wilcox has been looking at buffer_head code and found the
   documentation to be lacking.  The series is "Improve buffer head
   documentation".
 
 - Multi-size THPs get more work, this time from Lance Yang.  His series
   "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes
   the freeing of these things.
 
 - Kemeng Shi has added more userspace-visible writeback instrumentation
   in the series "Improve visibility of writeback".
 
 - Kemeng Shi then sent some maintenance work on top in the series "Fix
   and cleanups to page-writeback".
 
 - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the
   series "Improve anon_vma scalability for anon VMAs".  Intel's test bot
   reported an improbable 3x improvement in one test.
 
 - SeongJae Park adds some DAMON feature work in the series
 
 	"mm/damon: add a DAMOS filter type for page granularity access recheck"
 	"selftests/damon: add DAMOS quota goal test"
 
 - Also some maintenance work in the series
 
 	"mm/damon/paddr: simplify page level access re-check for pageout"
 	"mm/damon: misc fixes and improvements"
 
 - David Hildenbrand has disabled some known-to-fail selftests ni the
   series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL".
 
 - memcg metadata storage optimizations from Shakeel Butt in "memcg:
   reduce memory consumption by memcg stats".
 
 - DAX fixes and maintenance work from Vishal Verma in the series
   "dax/bus.c: Fixups for dax-bus locking".
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Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
2024-05-19 09:21:03 -07:00
Linus Torvalds
cd97950cbc slab updates for 6.10
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Merge tag 'slab-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:
 "This time it's mostly random cleanups and fixes, with two performance
  fixes that might have significant impact, but limited to systems
  experiencing particular bad corner case scenarios rather than general
  performance improvements.

  The memcg hook changes are going through the mm tree due to
  dependencies.

   - Prevent stalls when reading /proc/slabinfo (Jianfeng Wang)

     This fixes the long-standing problem that can happen with workloads
     that have alloc/free patterns resulting in many partially used
     slabs (in e.g. dentry cache). Reading /proc/slabinfo will traverse
     the long partial slab list under spinlock with disabled irqs and
     thus can stall other processes or even trigger the lockup
     detection. The traversal is only done to count free objects so that
     <active_objs> column can be reported along with <num_objs>.

     To avoid affecting fast paths with another shared counter
     (attempted in the past) or complex partial list traversal schemes
     that allow rescheduling, the chosen solution resorts to
     approximation - when the partial list is over 10000 slabs long, we
     will only traverse first 5000 slabs from head and tail each and use
     the average of those to estimate the whole list. Both head and tail
     are used as the slabs near head to tend to have more free objects
     than the slabs towards the tail.

     It is expected the approximation should not break existing
     /proc/slabinfo consumers. The <num_objs> field is still accurate
     and reflects the overall kmem_cache footprint. The <active_objs>
     was already imprecise due to cpu and percpu-partial slabs, so can't
     be relied upon to determine exact cache usage. The difference
     between <active_objs> and <num_objs> is mainly useful to determine
     the slab fragmentation, and that will be possible even with the
     approximation in place.

   - Prevent allocating many slabs when a NUMA node is full (Chen Jun)

     Currently, on NUMA systems with a node under significantly bigger
     pressure than other nodes, the fallback strategy may result in each
     kmalloc_node() that can't be safisfied from the preferred node, to
     allocate a new slab on a fallback node, and not reuse the slabs
     already on that node's partial list.

     This is now fixed and partial lists of fallback nodes are checked
     even for kmalloc_node() allocations. It's still preferred to
     allocate a new slab on the requested node before a fallback, but
     only with a GFP_NOWAIT attempt, which will fail quickly when the
     node is under a significant memory pressure.

   - More SLAB removal related cleanups (Xiu Jianfeng, Hyunmin Lee)

   - Fix slub_kunit self-test with hardened freelists (Guenter Roeck)

   - Mark racy accesses for KCSAN (linke li)

   - Misc cleanups (Xiongwei Song, Haifeng Xu, Sangyun Kim)"

* tag 'slab-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slub: remove the check for NULL kmalloc_caches
  mm/slub: create kmalloc 96 and 192 caches regardless cache size order
  mm/slub: mark racy access on slab->freelist
  slub: use count_partial_free_approx() in slab_out_of_memory()
  slub: introduce count_partial_free_approx()
  slub: Set __GFP_COMP in kmem_cache by default
  mm/slub: remove duplicate initialization for early_kmem_cache_node_alloc()
  mm/slub: correct comment in do_slab_free()
  mm/slub, kunit: Use inverted data to corrupt kmem cache
  mm/slub: simplify get_partial_node()
  mm/slub: add slub_get_cpu_partial() helper
  mm/slub: remove the check of !kmem_cache_has_cpu_partial()
  mm/slub: Reduce memory consumption in extreme scenarios
  mm/slub: mark racy accesses on slab->slabs
  mm/slub: remove dummy slabinfo functions
2024-05-13 10:28:34 -07:00
linke li
844776cb65 mm/slub: mark racy access on slab->freelist
In deactivate_slab(), slab->freelist can be changed concurrently. Mark
data race on slab->freelist as benign using READ_ONCE.

This patch is aimed at reducing the number of benign races reported by
KCSAN in order to focus future debugging effort on harmful races.

Signed-off-by: linke li <lilinke99@qq.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-02 14:19:21 +02:00
Nicolas Bouchinet
8f828aa488 mm/slub: avoid zeroing outside-object freepointer for single free
Commit 284f17ac13 ("mm/slub: handle bulk and single object freeing
separately") splits single and bulk object freeing in two functions
slab_free() and slab_free_bulk() which leads slab_free() to call
slab_free_hook() directly instead of slab_free_freelist_hook().

If `init_on_free` is set, slab_free_hook() zeroes the object.
Afterward, if `slub_debug=F` and `CONFIG_SLAB_FREELIST_HARDENED` are
set, the do_slab_free() slowpath executes freelist consistency
checks and try to decode a zeroed freepointer which leads to a
"Freepointer corrupt" detection in check_object().

During bulk free, slab_free_freelist_hook() isn't affected as it always
sets it objects freepointer using set_freepointer() to maintain its
reconstructed freelist after `init_on_free`.

For single free, object's freepointer thus needs to be avoided when
stored outside the object if `init_on_free` is set. The freepointer left
as is, check_object() may later detect an invalid pointer value due to
objects overflow.

To reproduce, set `slub_debug=FU init_on_free=1 log_level=7` on the
command line of a kernel build with `CONFIG_SLAB_FREELIST_HARDENED=y`.

dmesg sample log:
[   10.708715] =============================================================================
[   10.710323] BUG kmalloc-rnd-05-32 (Tainted: G    B           T ): Freepointer corrupt
[   10.712695] -----------------------------------------------------------------------------
[   10.712695]
[   10.712695] Slab 0xffffd8bdc400d580 objects=32 used=4 fp=0xffff9d9a80356f80 flags=0x200000000000a00(workingset|slab|node=0|zone=2)
[   10.716698] Object 0xffff9d9a80356600 @offset=1536 fp=0x7ee4f480ce0ecd7c
[   10.716698]
[   10.716698] Bytes b4 ffff9d9a803565f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.720703] Object   ffff9d9a80356600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.720703] Object   ffff9d9a80356610: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.724696] Padding  ffff9d9a8035666c: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.724696] Padding  ffff9d9a8035667c: 00 00 00 00                                      ....
[   10.724696] FIX kmalloc-rnd-05-32: Object at 0xffff9d9a80356600 not freed

Fixes: 284f17ac13 ("mm/slub: handle bulk and single object freeing separately")
Cc: <stable@vger.kernel.org>
Co-developed-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@ssi.gouv.fr>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-01 17:28:56 +02:00
Vlastimil Babka
e6100a4590 mm, slab: move slab_memcg hooks to mm/memcontrol.c
The hooks make multiple calls to functions in mm/memcontrol.c, including
to th current_obj_cgroup() marked __always_inline.  It might be faster to
make a single call to the hook in mm/memcontrol.c instead.  The hooks also
don't use almost anything from mm/slub.c.  obj_full_size() can move with
the hooks and cache_vmstat_idx() to the internal mm/slab.h

Link: https://lkml.kernel.org/r/20240326-slab-memcg-v3-2-d85d2563287a@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:16 -07:00
Vlastimil Babka
9f9796b413 mm, slab: move memcg charging to post-alloc hook
Patch series "memcg_kmem hooks refactoring", v3.


This patch (of 2):

The MEMCG_KMEM integration with slab currently relies on two hooks during
allocation.  memcg_slab_pre_alloc_hook() determines the objcg and charges
it, and memcg_slab_post_alloc_hook() assigns the objcg pointer to the
allocated object(s).

As Linus pointed out, this is unnecessarily complex.  Failing to charge
due to memcg limits should be rare, so we can optimistically allocate the
object(s) and do the charging together with assigning the objcg pointer in
a single post_alloc hook.  In the rare case the charging fails, we can
free the object(s) back.

This simplifies the code (no need to pass around the objcg pointer) and
potentially allows to separate charging from allocation in cases where
it's common that the allocation would be immediately freed, and the memcg
handling overhead could be saved.

[vbabka@suse.cz: fix call to memcg_alloc_abort_single()]
  Link: https://lkml.kernel.org/r/4af50be2-4109-45e5-8a36-2136252a635e@suse.cz
[roman.gushchin@linux.dev: comment fixup]
  Link: https://lkml.kernel.org/r/Zg2LsNm6twOmG69l@P9FQF9L96D.corp.robot.car
Link: https://lkml.kernel.org/r/20240326-slab-memcg-v3-0-d85d2563287a@suse.cz
Link: https://lkml.kernel.org/r/20240326-slab-memcg-v3-1-d85d2563287a@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/all/CAHk-=whYOOdM7jWy5jdrAm8LxcgCMFyk2bt8fYYvZzM4U-zAQA@mail.gmail.com/
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:16 -07:00
Matthew Wilcox (Oracle)
5e0debe012 slub: remove use of page->flags
Use slub->__page_flags instead.  We can also remove the assertion that
it's not a tail page as struct slab never points to a tail page.

Link: https://lkml.kernel.org/r/20240326171045.410737-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:15 -07:00
Kees Cook
3b89ec4174 mm/slub: avoid recursive loop with kmemleak
The system will immediate fill up stack and crash when both
CONFIG_DEBUG_KMEMLEAK and CONFIG_MEM_ALLOC_PROFILING are enabled.  Avoid
allocation tagging of kmemleak caches, otherwise recursive allocation
tracking occurs.

Link: https://lkml.kernel.org/r/20240425205516.work.220-kees@kernel.org
Fixes: 279bb991b4d9 ("mm/slab: add allocation accounting into slab allocation and free paths")
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:59 -07:00
Suren Baghdasaryan
09c46563ff codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocations
If slabobj_ext vector allocation for a slab object fails and later on it
succeeds for another object in the same slab, the slabobj_ext for the
original object will be NULL and will be flagged in case when
CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled.

Mark failed slabobj_ext vector allocations using a new objext_flags flag
stored in the lower bits of slab->obj_exts.  When new allocation succeeds
it marks all tag references in the same slabobj_ext vector as empty to
avoid warnings implemented by CONFIG_MEM_ALLOC_PROFILING_DEBUG checks.

Link: https://lkml.kernel.org/r/20240321163705.3067592-36-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:58 -07:00
Suren Baghdasaryan
239d6c96d8 codetag: debug: skip objext checking when it's for objext itself
objext objects are created with __GFP_NO_OBJ_EXT flag and therefore have
no corresponding objext themselves (otherwise we would get an infinite
recursion). When freeing these objects their codetag will be empty and
when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled this will lead to false
warnings. Introduce CODETAG_EMPTY special codetag value to mark
allocations which intentionally lack codetag to avoid these warnings.
Set objext codetags to CODETAG_EMPTY before freeing to indicate that
the codetag is expected to be empty.

Link: https://lkml.kernel.org/r/20240321163705.3067592-34-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:57 -07:00
Suren Baghdasaryan
7bd230a266 mm/slab: enable slab allocation tagging for kmalloc and friends
Redefine kmalloc, krealloc, kzalloc, kcalloc, etc. to record allocations
and deallocations done by these functions.

[surenb@google.com: undo _noprof additions in the documentation]
  Link: https://lkml.kernel.org/r/20240326231453.1206227-7-surenb@google.com
[rdunlap@infradead.org: fix kcalloc() kernel-doc warnings]
  Link: https://lkml.kernel.org/r/20240327044649.9199-1-rdunlap@infradead.org
Link: https://lkml.kernel.org/r/20240321163705.3067592-26-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:55 -07:00
Suren Baghdasaryan
4b87369646 mm/slab: add allocation accounting into slab allocation and free paths
Account slab allocations using codetag reference embedded into slabobj_ext.

Link: https://lkml.kernel.org/r/20240321163705.3067592-24-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:55 -07:00
Suren Baghdasaryan
45012241ec mm/slab: introduce SLAB_NO_OBJ_EXT to avoid obj_ext creation
Slab extension objects can't be allocated before slab infrastructure is
initialized.  Some caches, like kmem_cache and kmem_cache_node, are
created before slab infrastructure is initialized.  Objects from these
caches can't have extension objects.  Introduce SLAB_NO_OBJ_EXT slab flag
to mark these caches and avoid creating extensions for objects allocated
from these slabs.

Link: https://lkml.kernel.org/r/20240321163705.3067592-9-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:51 -07:00
Suren Baghdasaryan
768c33be1b mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creation
Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations
when allocating slabobj_ext on a slab.

Link: https://lkml.kernel.org/r/20240321163705.3067592-8-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:51 -07:00
Suren Baghdasaryan
21c690a349 mm: introduce slabobj_ext to support slab object extensions
Currently slab pages can store only vectors of obj_cgroup pointers in
page->memcg_data.  Introduce slabobj_ext structure to allow more data to
be stored for each slab object.  Wrap obj_cgroup into slabobj_ext to
support current functionality while allowing to extend slabobj_ext in the
future.

Link: https://lkml.kernel.org/r/20240321163705.3067592-7-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:51 -07:00