lib/stackdepot: move stack_record struct definition into the header

In order to move the heavy lifting into page_owner code, this one needs to
have access to the stack_record structure, which right now sits in
lib/stackdepot.c.  Move it to the stackdepot.h header so page_owner can
access stack_record's struct fields.

Link: https://lkml.kernel.org/r/20240215215907.20121-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index adcbb8f..c4b5ad5 100644 (file)
--- 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 c043a41..514b8d4 100644 (file)
--- 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;