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-rw-r--r--include/linux/stackdepot.h26
-rw-r--r--lib/stackdepot.c67
-rw-r--r--mm/page_owner.c9
3 files changed, 73 insertions, 29 deletions
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index 17f992fe6355..bc2797955de9 100644
--- a/include/linux/stackdepot.h
+++ b/include/linux/stackdepot.h
@@ -20,18 +20,36 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries,
gfp_t gfp_flags, bool can_alloc);
/*
- * Every user of stack depot has to call this during its own init when it's
- * decided that it will be calling stack_depot_save() later.
+ * Every user of stack depot has to call stack_depot_init() during its own init
+ * when it's decided that it will be calling stack_depot_save() later. This is
+ * recommended for e.g. modules initialized later in the boot process, when
+ * slab_is_available() is true.
*
* The alternative is to select STACKDEPOT_ALWAYS_INIT to have stack depot
* enabled as part of mm_init(), for subsystems where it's known at compile time
* that stack depot will be used.
+ *
+ * Another alternative is to call stack_depot_want_early_init(), when the
+ * decision to use stack depot is taken e.g. when evaluating kernel boot
+ * parameters, which precedes the enablement point in mm_init().
+ *
+ * stack_depot_init() and stack_depot_want_early_init() can be called regardless
+ * of CONFIG_STACKDEPOT and are no-op when disabled. The actual save/fetch/print
+ * functions should only be called from code that makes sure CONFIG_STACKDEPOT
+ * is enabled.
*/
+#ifdef CONFIG_STACKDEPOT
int stack_depot_init(void);
-#ifdef CONFIG_STACKDEPOT_ALWAYS_INIT
-static inline int stack_depot_early_init(void) { return stack_depot_init(); }
+void __init stack_depot_want_early_init(void);
+
+/* This is supposed to be called only from mm_init() */
+int __init stack_depot_early_init(void);
#else
+static inline int stack_depot_init(void) { return 0; }
+
+static inline void stack_depot_want_early_init(void) { }
+
static inline int stack_depot_early_init(void) { return 0; }
#endif
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index bf5ba9af0500..5ca0d086ef4a 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -66,6 +66,9 @@ struct stack_record {
unsigned long entries[]; /* Variable-sized array of entries. */
};
+static bool __stack_depot_want_early_init __initdata = IS_ENABLED(CONFIG_STACKDEPOT_ALWAYS_INIT);
+static bool __stack_depot_early_init_passed __initdata;
+
static void *stack_slabs[STACK_ALLOC_MAX_SLABS];
static int depot_index;
@@ -162,38 +165,58 @@ static int __init is_stack_depot_disabled(char *str)
}
early_param("stack_depot_disable", is_stack_depot_disabled);
-/*
- * __ref because of memblock_alloc(), which will not be actually called after
- * the __init code is gone, because at that point slab_is_available() is true
- */
-__ref int stack_depot_init(void)
+void __init stack_depot_want_early_init(void)
+{
+ /* Too late to request early init now */
+ WARN_ON(__stack_depot_early_init_passed);
+
+ __stack_depot_want_early_init = true;
+}
+
+int __init stack_depot_early_init(void)
+{
+ size_t size;
+
+ /* This is supposed to be called only once, from mm_init() */
+ if (WARN_ON(__stack_depot_early_init_passed))
+ return 0;
+
+ __stack_depot_early_init_passed = true;
+
+ if (!__stack_depot_want_early_init || stack_depot_disable)
+ return 0;
+
+ size = (STACK_HASH_SIZE * sizeof(struct stack_record *));
+ pr_info("Stack Depot early init allocating hash table with memblock_alloc, %zu bytes\n",
+ size);
+ stack_table = memblock_alloc(size, SMP_CACHE_BYTES);
+
+ if (!stack_table) {
+ pr_err("Stack Depot hash table allocation failed, disabling\n");
+ stack_depot_disable = true;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int stack_depot_init(void)
{
static DEFINE_MUTEX(stack_depot_init_mutex);
+ int ret = 0;
mutex_lock(&stack_depot_init_mutex);
if (!stack_depot_disable && !stack_table) {
- size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *));
- int i;
-
- if (slab_is_available()) {
- pr_info("Stack Depot allocating hash table with kvmalloc\n");
- stack_table = kvmalloc(size, GFP_KERNEL);
- } else {
- pr_info("Stack Depot allocating hash table with memblock_alloc\n");
- stack_table = memblock_alloc(size, SMP_CACHE_BYTES);
- }
- if (stack_table) {
- for (i = 0; i < STACK_HASH_SIZE; i++)
- stack_table[i] = NULL;
- } else {
+ pr_info("Stack Depot allocating hash table with kvcalloc\n");
+ stack_table = kvcalloc(STACK_HASH_SIZE, sizeof(struct stack_record *), GFP_KERNEL);
+ if (!stack_table) {
pr_err("Stack Depot hash table allocation failed, disabling\n");
stack_depot_disable = true;
- mutex_unlock(&stack_depot_init_mutex);
- return -ENOMEM;
+ ret = -ENOMEM;
}
}
mutex_unlock(&stack_depot_init_mutex);
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(stack_depot_init);
diff --git a/mm/page_owner.c b/mm/page_owner.c
index fb3a05fdebdb..2743062e92c2 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -45,7 +45,12 @@ static void init_early_allocated_pages(void);
static int __init early_page_owner_param(char *buf)
{
- return kstrtobool(buf, &page_owner_enabled);
+ int ret = kstrtobool(buf, &page_owner_enabled);
+
+ if (page_owner_enabled)
+ stack_depot_want_early_init();
+
+ return ret;
}
early_param("page_owner", early_page_owner_param);
@@ -83,8 +88,6 @@ static __init void init_page_owner(void)
if (!page_owner_enabled)
return;
- stack_depot_init();
-
register_dummy_stack();
register_failure_stack();
register_early_stack();