diff --git a/include/linux/slab.h b/include/linux/slab.h index 0fefdf528e0d2e08287fe349dec0aeeed3e5a78b..352e3f082acce01706d23bf66a46760cb1267c6f 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -119,6 +119,12 @@ */ #define SLAB_NO_USER_FLAGS ((slab_flags_t __force)0x10000000U) +#ifdef CONFIG_KFENCE +#define SLAB_SKIP_KFENCE ((slab_flags_t __force)0x20000000U) +#else +#define SLAB_SKIP_KFENCE 0 +#endif + /* The following flags affect the page allocator grouping pages by mobility */ /* Objects are reclaimable */ #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index c252081b11dfe57f5d608f385785787c06b72347..8c08ae2101d7a254f162bd7e95c217afba10d2c4 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -1003,6 +1003,13 @@ void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) return NULL; } + /* + * Skip allocations for this slab, if KFENCE has been disabled for + * this slab. + */ + if (s->flags & SLAB_SKIP_KFENCE) + return NULL; + if (atomic_inc_return(&kfence_allocation_gate) > 1) return NULL; #ifdef CONFIG_KFENCE_STATIC_KEYS diff --git a/mm/slub.c b/mm/slub.c index 862dbd9af4f521fe820a9b5bdb69e7a726ba3d5d..6953c3367bc2003f2f06a31e4c5bd0c0055e058e 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5745,6 +5745,29 @@ STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node); STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain); #endif /* CONFIG_SLUB_STATS */ +#ifdef CONFIG_KFENCE +static ssize_t skip_kfence_show(struct kmem_cache *s, char *buf) +{ + return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_SKIP_KFENCE)); +} + +static ssize_t skip_kfence_store(struct kmem_cache *s, + const char *buf, size_t length) +{ + int ret = length; + + if (buf[0] == '0') + s->flags &= ~SLAB_SKIP_KFENCE; + else if (buf[0] == '1') + s->flags |= SLAB_SKIP_KFENCE; + else + ret = -EINVAL; + + return ret; +} +SLAB_ATTR(skip_kfence); +#endif + static struct attribute *slab_attrs[] = { &slab_size_attr.attr, &object_size_attr.attr, @@ -5812,6 +5835,9 @@ static struct attribute *slab_attrs[] = { &failslab_attr.attr, #endif &usersize_attr.attr, +#ifdef CONFIG_KFENCE + &skip_kfence_attr.attr, +#endif NULL };