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authorLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 09:13:06 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 09:13:06 -0800
commit893660b0e1c8d127960ae921f55983b435664e15 (patch)
tree1cc9a3f9364af669964aa12d81c617e31bdb82e2 /lib
parent98d0052d0d9dcd5323833482712b5799ed0bbb0b (diff)
parentdc19745ad0e46c1a069540973e376cff0130443c (diff)
Merge tag 'slab-for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka: - SLOB deprecation and SLUB_TINY The SLOB allocator adds maintenance burden and stands in the way of API improvements [1]. Deprecate it by renaming the config option (to make users notice) to CONFIG_SLOB_DEPRECATED with updated help text. SLUB should be used instead as SLAB will be the next on the removal list. Based on reports from a riscv k210 board with 8MB RAM, add a CONFIG_SLUB_TINY option to minimize SLUB's memory usage at the expense of scalability. This has resolved the k210 regression [2] so in case there are no others (that wouldn't be resolvable by further tweaks to SLUB_TINY) plan is to remove SLOB in a few cycles. Existing defconfigs with CONFIG_SLOB are converted to CONFIG_SLUB_TINY. - kmalloc() slub_debug redzone improvements A series from Feng Tang that builds on the tracking or requested size for kmalloc() allocations (for caches with debugging enabled) added in 6.1, to make redzone checks consider the requested size and not the rounded up one, in order to catch more subtle buffer overruns. Includes new slub_kunit test. - struct slab fields reordering to accomodate larger rcu_head RCU folks would like to grow rcu_head with debugging options, which breaks current struct slab layout's assumptions, so reorganize it to make this possible. - Miscellaneous improvements/fixes: - __alloc_size checking compiler workaround (Kees Cook) - Optimize and cleanup SLUB's sysfs init (Rasmus Villemoes) - Make SLAB compatible with PROVE_RAW_LOCK_NESTING (Jiri Kosina) - Correct SLUB's percpu allocation estimates (Baoquan He) - Re-enableS LUB's run-time failslab sysfs control (Alexander Atanasov) - Make tools/vm/slabinfo more user friendly when not run as root (Rong Tao) - Dead code removal in SLUB (Hyeonggon Yoo) * tag 'slab-for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (31 commits) mm, slob: rename CONFIG_SLOB to CONFIG_SLOB_DEPRECATED mm, slub: don't aggressively inline with CONFIG_SLUB_TINY mm, slub: remove percpu slabs with CONFIG_SLUB_TINY mm, slub: split out allocations from pre/post hooks mm/slub, kunit: Add a test case for kmalloc redzone check mm/slub, kunit: add SLAB_SKIP_KFENCE flag for cache creation mm, slub: refactor free debug processing mm, slab: ignore SLAB_RECLAIM_ACCOUNT with CONFIG_SLUB_TINY mm, slub: don't create kmalloc-rcl caches with CONFIG_SLUB_TINY mm, slub: lower the default slub_max_order with CONFIG_SLUB_TINY mm, slub: retain no free slabs on partial list with CONFIG_SLUB_TINY mm, slub: disable SYSFS support with CONFIG_SLUB_TINY mm, slub: add CONFIG_SLUB_TINY mm, slab: ignore hardened usercopy parameters when disabled slab: Remove special-casing of const 0 size allocations slab: Clean up SLOB vs kmalloc() definition mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head mm/migrate: make isolate_movable_page() skip slab pages mm/slab: move and adjust kernel-doc for kmem_cache_alloc mm/slub, percpu: correct the calculation of early percpu allocation size ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.kasan2
-rw-r--r--lib/slub_kunit.c57
2 files changed, 48 insertions, 11 deletions
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index ca09b1cf8ee9..836f70393e22 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -37,7 +37,7 @@ menuconfig KASAN
(HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS)) && \
CC_HAS_WORKING_NOSANITIZE_ADDRESS) || \
HAVE_ARCH_KASAN_HW_TAGS
- depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB)
+ depends on (SLUB && SYSFS && !SLUB_TINY) || (SLAB && !DEBUG_SLAB)
select STACKDEPOT_ALWAYS_INIT
help
Enables KASAN (Kernel Address Sanitizer) - a dynamic memory safety
diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
index 7a0564d7cb7a..bdf358d520b4 100644
--- a/lib/slub_kunit.c
+++ b/lib/slub_kunit.c
@@ -9,10 +9,25 @@
static struct kunit_resource resource;
static int slab_errors;
+/*
+ * Wrapper function for kmem_cache_create(), which reduces 2 parameters:
+ * 'align' and 'ctor', and sets SLAB_SKIP_KFENCE flag to avoid getting an
+ * object from kfence pool, where the operation could be caught by both
+ * our test and kfence sanity check.
+ */
+static struct kmem_cache *test_kmem_cache_create(const char *name,
+ unsigned int size, slab_flags_t flags)
+{
+ struct kmem_cache *s = kmem_cache_create(name, size, 0,
+ (flags | SLAB_NO_USER_FLAGS), NULL);
+ s->flags |= SLAB_SKIP_KFENCE;
+ return s;
+}
+
static void test_clobber_zone(struct kunit *test)
{
- struct kmem_cache *s = kmem_cache_create("TestSlub_RZ_alloc", 64, 0,
- SLAB_RED_ZONE|SLAB_NO_USER_FLAGS, NULL);
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_alloc", 64,
+ SLAB_RED_ZONE);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kasan_disable_current();
@@ -29,8 +44,8 @@ static void test_clobber_zone(struct kunit *test)
#ifndef CONFIG_KASAN
static void test_next_pointer(struct kunit *test)
{
- struct kmem_cache *s = kmem_cache_create("TestSlub_next_ptr_free", 64, 0,
- SLAB_POISON|SLAB_NO_USER_FLAGS, NULL);
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_next_ptr_free",
+ 64, SLAB_POISON);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
unsigned long tmp;
unsigned long *ptr_addr;
@@ -74,8 +89,8 @@ static void test_next_pointer(struct kunit *test)
static void test_first_word(struct kunit *test)
{
- struct kmem_cache *s = kmem_cache_create("TestSlub_1th_word_free", 64, 0,
- SLAB_POISON|SLAB_NO_USER_FLAGS, NULL);
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_1th_word_free",
+ 64, SLAB_POISON);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kmem_cache_free(s, p);
@@ -89,8 +104,8 @@ static void test_first_word(struct kunit *test)
static void test_clobber_50th_byte(struct kunit *test)
{
- struct kmem_cache *s = kmem_cache_create("TestSlub_50th_word_free", 64, 0,
- SLAB_POISON|SLAB_NO_USER_FLAGS, NULL);
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_50th_word_free",
+ 64, SLAB_POISON);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kmem_cache_free(s, p);
@@ -105,8 +120,8 @@ static void test_clobber_50th_byte(struct kunit *test)
static void test_clobber_redzone_free(struct kunit *test)
{
- struct kmem_cache *s = kmem_cache_create("TestSlub_RZ_free", 64, 0,
- SLAB_RED_ZONE|SLAB_NO_USER_FLAGS, NULL);
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_free", 64,
+ SLAB_RED_ZONE);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kasan_disable_current();
@@ -120,6 +135,27 @@ static void test_clobber_redzone_free(struct kunit *test)
kmem_cache_destroy(s);
}
+static void test_kmalloc_redzone_access(struct kunit *test)
+{
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
+ SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
+ u8 *p = kmalloc_trace(s, GFP_KERNEL, 18);
+
+ kasan_disable_current();
+
+ /* Suppress the -Warray-bounds warning */
+ OPTIMIZER_HIDE_VAR(p);
+ p[18] = 0xab;
+ p[19] = 0xab;
+
+ validate_slab_cache(s);
+ KUNIT_EXPECT_EQ(test, 2, slab_errors);
+
+ kasan_enable_current();
+ kmem_cache_free(s, p);
+ kmem_cache_destroy(s);
+}
+
static int test_init(struct kunit *test)
{
slab_errors = 0;
@@ -139,6 +175,7 @@ static struct kunit_case test_cases[] = {
#endif
KUNIT_CASE(test_clobber_redzone_free),
+ KUNIT_CASE(test_kmalloc_redzone_access),
{}
};