kernel/linux.git/include/linux/slab.h, branch v5.10.258

mm/slab: make __free(kfree) accept error pointers

2025-10-29T13:01:17+00:00

commit cd7eb8f83fcf258f71e293f7fc52a70be8ed0128 upstream. Currently, if an automatically freed allocation is an error pointer that will lead to a crash. An example of this is in wm831x_gpio_dbg_show(). 171 char *label __free(kfree) = gpiochip_dup_line_label(chip, i); 172 if (IS_ERR(label)) { 173 dev_err(wm831x->dev, "Failed to duplicate label\n"); 174 continue; 175 } The auto clean up function should check for error pointers as well, otherwise we're going to keep hitting issues like this. Fixes: 54da6a092431 ("locking: Introduce __cleanup() based infrastructure") Cc: Signed-off-by: Dan Carpenter Acked-by: David Rientjes Signed-off-by: Vlastimil Babka Signed-off-by: Greg Kroah-Hartman

locking: Introduce __cleanup() based infrastructure

2025-10-29T13:01:15+00:00

[ Upstream commit 54da6a0924311c7cf5015533991e44fb8eb12773 ] Use __attribute__((__cleanup__(func))) to build: - simple auto-release pointers using __free() - 'classes' with constructor and destructor semantics for scope-based resource management. - lock guards based on the above classes. Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230612093537.614161713%40infradead.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

mm: remove kzfree() compatibility definition

2020-10-25T18:39:02+00:00

Commit 453431a54934 ("mm, treewide: rename kzfree() to kfree_sensitive()") renamed kzfree() to kfree_sensitive(), but it left a compatibility definition of kzfree() to avoid being too disruptive. Since then a few more instances of kzfree() have slipped in. Just get rid of them and remove the compatibility definition once and for all. Signed-off-by: Eric Biggers Signed-off-by: Linus Torvalds

include/linux/slab.h: fix a typo error in comment

2020-10-14T01:38:27+00:00

fix a typo error in slab.h "allocagtor" -> "allocator" Signed-off-by: tangjianqiang Signed-off-by: Andrew Morton Acked-by: Souptick Joarder Link: https://lkml.kernel.org/r/1600230053-24303-1-git-send-email-tangjianqiang@xiaomi.com Signed-off-by: Linus Torvalds

mm: memcg/slab: use a single set of kmem_caches for all allocations

2020-08-07T18:33:25+00:00

Instead of having two sets of kmem_caches: one for system-wide and non-accounted allocations and the second one shared by all accounted allocations, we can use just one. The idea is simple: space for obj_cgroup metadata can be allocated on demand and filled only for accounted allocations. It allows to remove a bunch of code which is required to handle kmem_cache clones for accounted allocations. There is no more need to create them, accumulate statistics, propagate attributes, etc. It's a quite significant simplification. Also, because the total number of slab_caches is reduced almost twice (not all kmem_caches have a memcg clone), some additional memory savings are expected. On my devvm it additionally saves about 3.5% of slab memory. [guro@fb.com: fix build on MIPS] Link: http://lkml.kernel.org/r/20200717214810.3733082-1-guro@fb.com Suggested-by: Johannes Weiner Signed-off-by: Roman Gushchin Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Reviewed-by: Shakeel Butt Cc: Christoph Lameter Cc: Michal Hocko Cc: Tejun Heo Cc: Naresh Kamboju Link: http://lkml.kernel.org/r/20200623174037.3951353-18-guro@fb.com Signed-off-by: Linus Torvalds

mm: memcg/slab: use a single set of kmem_caches for all accounted allocations

2020-08-07T18:33:25+00:00

This is fairly big but mostly red patch, which makes all accounted slab allocations use a single set of kmem_caches instead of creating a separate set for each memory cgroup. Because the number of non-root kmem_caches is now capped by the number of root kmem_caches, there is no need to shrink or destroy them prematurely. They can be perfectly destroyed together with their root counterparts. This allows to dramatically simplify the management of non-root kmem_caches and delete a ton of code. This patch performs the following changes: 1) introduces memcg_params.memcg_cache pointer to represent the kmem_cache which will be used for all non-root allocations 2) reuses the existing memcg kmem_cache creation mechanism to create memcg kmem_cache on the first allocation attempt 3) memcg kmem_caches are named -memcg, e.g. dentry-memcg 4) simplifies memcg_kmem_get_cache() to just return memcg kmem_cache or schedule it's creation and return the root cache 5) removes almost all non-root kmem_cache management code (separate refcounter, reparenting, shrinking, etc) 6) makes slab debugfs to display root_mem_cgroup css id and never show :dead and :deact flags in the memcg_slabinfo attribute. Following patches in the series will simplify the kmem_cache creation. Signed-off-by: Roman Gushchin Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Reviewed-by: Shakeel Butt Cc: Christoph Lameter Cc: Johannes Weiner Cc: Michal Hocko Cc: Tejun Heo Link: http://lkml.kernel.org/r/20200623174037.3951353-13-guro@fb.com Signed-off-by: Linus Torvalds

mm, treewide: rename kzfree() to kfree_sensitive()

2020-08-07T18:33:22+00:00

As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches Signed-off-by: Waiman Long Signed-off-by: Andrew Morton Acked-by: David Howells Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Jarkko Sakkinen Cc: James Morris Cc: "Serge E. Hallyn" Cc: Joe Perches Cc: Matthew Wilcox Cc: David Rientjes Cc: Dan Carpenter Cc: "Jason A . Donenfeld" Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds

docs: mm: slab.h: fix a broken cross-reference

2020-04-10T22:36:20+00:00

There is a typo at the cross-reference link, causing this warning: include/linux/slab.h:11: WARNING: undefined label: memory-allocation (if the link has no caption the label must precede a section header) Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Andrew Morton Cc: Jonathan Corbet Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Link: http://lkml.kernel.org/r/0aeac24235d356ebd935d11e147dcc6edbb6465c.1586359676.git.mchehab+huawei@kernel.org Signed-off-by: Linus Torvalds

mm: remove __krealloc

2020-02-04T03:05:24+00:00

Since 5.5-rc1 the last user of this function is gone, so remove the functionality. See commit 2ad9d7747c10 ("netfilter: conntrack: free extension area immediately") for details. Link: http://lkml.kernel.org/r/20191212223442.22141-1-fw@strlen.de Signed-off-by: Florian Westphal Acked-by: Andrew Morton Acked-by: David Rientjes Reviewed-by: David Hildenbrand Cc: Christoph Lameter Cc: Pekka Enberg Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, slab: remove unused kmalloc_size()

2019-12-01T14:29:17+00:00

The size of kmalloc can be obtained from kmalloc_info[], so remove kmalloc_size() that will not be used anymore. Link: http://lkml.kernel.org/r/1569241648-26908-3-git-send-email-lpf.vector@gmail.com Signed-off-by: Pengfei Li Acked-by: Vlastimil Babka Acked-by: Roman Gushchin Acked-by: David Rientjes Cc: Christoph Lameter Cc: Joonsoo Kim Cc: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds