diff options
Diffstat (limited to 'include/linux/stackdepot.h')
| -rw-r--r-- | include/linux/stackdepot.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index 3efa97d482cb..9ca7798d7a31 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -11,7 +11,53 @@ #ifndef _LINUX_STACKDEPOT_H #define _LINUX_STACKDEPOT_H +#include <linux/gfp.h> + typedef u32 depot_stack_handle_t; +/* + * Number of bits in the handle that stack depot doesn't use. Users may store + * information in them. + */ +#define STACK_DEPOT_EXTRA_BITS 5 + +depot_stack_handle_t __stack_depot_save(unsigned long *entries, + unsigned int nr_entries, + unsigned int extra_bits, + gfp_t gfp_flags, bool can_alloc); + +/* + * 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); + +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 depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t gfp_flags); @@ -19,4 +65,11 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries); +unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle); + +int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size, + int spaces); + +void stack_depot_print(depot_stack_handle_t stack); + #endif |