diff options
Diffstat (limited to 'include/linux/slab.h')
| -rw-r--r-- | include/linux/slab.h | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index 848c7c82ad5a..8228d1276a2f 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -19,6 +19,7 @@ #include <linux/workqueue.h> #include <linux/percpu-refcount.h> #include <linux/cleanup.h> +#include <linux/hash.h> /* @@ -345,6 +346,12 @@ static inline unsigned int arch_slab_minalign(void) #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \ (KMALLOC_MIN_SIZE) : 16) +#ifdef CONFIG_RANDOM_KMALLOC_CACHES +#define RANDOM_KMALLOC_CACHES_NR 15 // # of cache copies +#else +#define RANDOM_KMALLOC_CACHES_NR 0 +#endif + /* * Whenever changing this, take care of that kmalloc_type() and * create_kmalloc_caches() still work as intended. @@ -361,6 +368,8 @@ enum kmalloc_cache_type { #ifndef CONFIG_MEMCG_KMEM KMALLOC_CGROUP = KMALLOC_NORMAL, #endif + KMALLOC_RANDOM_START = KMALLOC_NORMAL, + KMALLOC_RANDOM_END = KMALLOC_RANDOM_START + RANDOM_KMALLOC_CACHES_NR, #ifdef CONFIG_SLUB_TINY KMALLOC_RECLAIM = KMALLOC_NORMAL, #else @@ -386,14 +395,22 @@ kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1]; (IS_ENABLED(CONFIG_ZONE_DMA) ? __GFP_DMA : 0) | \ (IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0)) -static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) +extern unsigned long random_kmalloc_seed; + +static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags, unsigned long caller) { /* * The most common case is KMALLOC_NORMAL, so test for it * with a single branch for all the relevant flags. */ if (likely((flags & KMALLOC_NOT_NORMAL_BITS) == 0)) +#ifdef CONFIG_RANDOM_KMALLOC_CACHES + /* RANDOM_KMALLOC_CACHES_NR (=15) copies + the KMALLOC_NORMAL */ + return KMALLOC_RANDOM_START + hash_64(caller ^ random_kmalloc_seed, + ilog2(RANDOM_KMALLOC_CACHES_NR + 1)); +#else return KMALLOC_NORMAL; +#endif /* * At least one of the flags has to be set. Their priorities in @@ -580,7 +597,7 @@ static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags) index = kmalloc_index(size); return kmalloc_trace( - kmalloc_caches[kmalloc_type(flags)][index], + kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index], flags, size); } return __kmalloc(size, flags); @@ -596,7 +613,7 @@ static __always_inline __alloc_size(1) void *kmalloc_node(size_t size, gfp_t fla index = kmalloc_index(size); return kmalloc_node_trace( - kmalloc_caches[kmalloc_type(flags)][index], + kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index], flags, node, size); } return __kmalloc_node(size, flags, node); |