diff options
| -rw-r--r-- | include/linux/stackdepot.h | 47 | ||||
| -rw-r--r-- | lib/stackdepot.c | 43 |
2 files changed, 47 insertions, 43 deletions
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index adcbb8f23600..c4b5ad57c066 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -30,6 +30,53 @@ typedef u32 depot_stack_handle_t; */ #define STACK_DEPOT_EXTRA_BITS 5 +#define DEPOT_HANDLE_BITS (sizeof(depot_stack_handle_t) * 8) + +#define DEPOT_POOL_ORDER 2 /* Pool size order, 4 pages */ +#define DEPOT_POOL_SIZE (1LL << (PAGE_SHIFT + DEPOT_POOL_ORDER)) +#define DEPOT_STACK_ALIGN 4 +#define DEPOT_OFFSET_BITS (DEPOT_POOL_ORDER + PAGE_SHIFT - DEPOT_STACK_ALIGN) +#define DEPOT_POOL_INDEX_BITS (DEPOT_HANDLE_BITS - DEPOT_OFFSET_BITS - \ + STACK_DEPOT_EXTRA_BITS) + +#ifdef CONFIG_STACKDEPOT +/* Compact structure that stores a reference to a stack. */ +union handle_parts { + depot_stack_handle_t handle; + struct { + /* pool_index is offset by 1 */ + u32 pool_index : DEPOT_POOL_INDEX_BITS; + u32 offset : DEPOT_OFFSET_BITS; + u32 extra : STACK_DEPOT_EXTRA_BITS; + }; +}; + +struct stack_record { + struct list_head hash_list; /* Links in the hash table */ + u32 hash; /* Hash in hash table */ + u32 size; /* Number of stored frames */ + union handle_parts handle; /* Constant after initialization */ + refcount_t count; + union { + unsigned long entries[CONFIG_STACKDEPOT_MAX_FRAMES]; /* Frames */ + struct { + /* + * An important invariant of the implementation is to + * only place a stack record onto the freelist iff its + * refcount is zero. Because stack records with a zero + * refcount are never considered as valid, it is safe to + * union @entries and freelist management state below. + * Conversely, as soon as an entry is off the freelist + * and its refcount becomes non-zero, the below must not + * be accessed until being placed back on the freelist. + */ + struct list_head free_list; /* Links in the freelist */ + unsigned long rcu_state; /* RCU cookie */ + }; + }; +}; +#endif + typedef u32 depot_flags_t; /* diff --git a/lib/stackdepot.c b/lib/stackdepot.c index c043a4186bc5..514b8d40ff57 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -36,55 +36,12 @@ #include <linux/memblock.h> #include <linux/kasan-enabled.h> -#define DEPOT_HANDLE_BITS (sizeof(depot_stack_handle_t) * 8) - -#define DEPOT_POOL_ORDER 2 /* Pool size order, 4 pages */ -#define DEPOT_POOL_SIZE (1LL << (PAGE_SHIFT + DEPOT_POOL_ORDER)) -#define DEPOT_STACK_ALIGN 4 -#define DEPOT_OFFSET_BITS (DEPOT_POOL_ORDER + PAGE_SHIFT - DEPOT_STACK_ALIGN) -#define DEPOT_POOL_INDEX_BITS (DEPOT_HANDLE_BITS - DEPOT_OFFSET_BITS - \ - STACK_DEPOT_EXTRA_BITS) #define DEPOT_POOLS_CAP 8192 /* The pool_index is offset by 1 so the first record does not have a 0 handle. */ #define DEPOT_MAX_POOLS \ (((1LL << (DEPOT_POOL_INDEX_BITS)) - 1 < DEPOT_POOLS_CAP) ? \ (1LL << (DEPOT_POOL_INDEX_BITS)) - 1 : DEPOT_POOLS_CAP) -/* Compact structure that stores a reference to a stack. */ -union handle_parts { - depot_stack_handle_t handle; - struct { - u32 pool_index : DEPOT_POOL_INDEX_BITS; /* pool_index is offset by 1 */ - u32 offset : DEPOT_OFFSET_BITS; - u32 extra : STACK_DEPOT_EXTRA_BITS; - }; -}; - -struct stack_record { - struct list_head hash_list; /* Links in the hash table */ - u32 hash; /* Hash in hash table */ - u32 size; /* Number of stored frames */ - union handle_parts handle; /* Constant after initialization */ - refcount_t count; - union { - unsigned long entries[CONFIG_STACKDEPOT_MAX_FRAMES]; /* Frames */ - struct { - /* - * An important invariant of the implementation is to - * only place a stack record onto the freelist iff its - * refcount is zero. Because stack records with a zero - * refcount are never considered as valid, it is safe to - * union @entries and freelist management state below. - * Conversely, as soon as an entry is off the freelist - * and its refcount becomes non-zero, the below must not - * be accessed until being placed back on the freelist. - */ - struct list_head free_list; /* Links in the freelist */ - unsigned long rcu_state; /* RCU cookie */ - }; - }; -}; - static bool stack_depot_disabled; static bool __stack_depot_early_init_requested __initdata = IS_ENABLED(CONFIG_STACKDEPOT_ALWAYS_INIT); static bool __stack_depot_early_init_passed __initdata; |