diff options
| -rw-r--r-- | Documentation/dev-tools/kasan.rst | 3 | ||||
| -rw-r--r-- | mm/page_owner.c | 28 |
2 files changed, 10 insertions, 21 deletions
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst index b72d07d70239..525296121d89 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -41,6 +41,9 @@ smaller binary while the latter is 1.1 - 2 times faster. Both KASAN modes work with both SLUB and SLAB memory allocators. For better bug detection and nicer reporting, enable CONFIG_STACKTRACE. +To augment reports with last allocation and freeing stack of the physical page, +it is recommended to enable also CONFIG_PAGE_OWNER and boot with page_owner=on. + To disable instrumentation for specific files or directories, add a line similar to the following to the respective kernel Makefile: diff --git a/mm/page_owner.c b/mm/page_owner.c index d3cf5d336ccf..de1916ac3e24 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -24,12 +24,10 @@ struct page_owner { short last_migrate_reason; gfp_t gfp_mask; depot_stack_handle_t handle; -#ifdef CONFIG_DEBUG_PAGEALLOC depot_stack_handle_t free_handle; -#endif }; -static bool page_owner_disabled = true; +static bool page_owner_enabled = false; DEFINE_STATIC_KEY_FALSE(page_owner_inited); static depot_stack_handle_t dummy_handle; @@ -44,7 +42,7 @@ static int __init early_page_owner_param(char *buf) return -EINVAL; if (strcmp(buf, "on") == 0) - page_owner_disabled = false; + page_owner_enabled = true; return 0; } @@ -52,10 +50,7 @@ early_param("page_owner", early_page_owner_param); static bool need_page_owner(void) { - if (page_owner_disabled) - return false; - - return true; + return page_owner_enabled; } static __always_inline depot_stack_handle_t create_dummy_stack(void) @@ -84,7 +79,7 @@ static noinline void register_early_stack(void) static void init_page_owner(void) { - if (page_owner_disabled) + if (!page_owner_enabled) return; register_dummy_stack(); @@ -148,25 +143,18 @@ void __reset_page_owner(struct page *page, unsigned int order) { int i; struct page_ext *page_ext; -#ifdef CONFIG_DEBUG_PAGEALLOC depot_stack_handle_t handle = 0; struct page_owner *page_owner; - if (debug_pagealloc_enabled()) - handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); -#endif + handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); page_ext = lookup_page_ext(page); if (unlikely(!page_ext)) return; for (i = 0; i < (1 << order); i++) { __clear_bit(PAGE_EXT_OWNER_ACTIVE, &page_ext->flags); -#ifdef CONFIG_DEBUG_PAGEALLOC - if (debug_pagealloc_enabled()) { - page_owner = get_page_owner(page_ext); - page_owner->free_handle = handle; - } -#endif + page_owner = get_page_owner(page_ext); + page_owner->free_handle = handle; page_ext = page_ext_next(page_ext); } } @@ -450,7 +438,6 @@ void __dump_page_owner(struct page *page) stack_trace_print(entries, nr_entries, 0); } -#ifdef CONFIG_DEBUG_PAGEALLOC handle = READ_ONCE(page_owner->free_handle); if (!handle) { pr_alert("page_owner free stack trace missing\n"); @@ -459,7 +446,6 @@ void __dump_page_owner(struct page *page) pr_alert("page last free stack trace:\n"); stack_trace_print(entries, nr_entries, 0); } -#endif if (page_owner->last_migrate_reason != -1) pr_alert("page has been migrated, last migrate reason: %s\n", |