kernel_optimize_test/include/linux/debugobjects.h
Stephen Boyd aedcade6f4 debugobjects: Allow debug_obj_descr to be const
The debugobject core could be slightly harder to corrupt if the
debug_obj_descr would be a pointer to const memory.

Depending on the architecture, const data structures are placed into
read-only memory and thus are harder to corrupt or hijack.

This descriptor is used to fix up stuff like timers and workqueues when
core kernel data structures are busted, so moving the descriptors to
read-only memory will make debugobjects more resilient to something going
wrong and then corrupting the function pointers inside struct
debug_obj_descr.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200815004027.2046113-2-swboyd@chromium.org
2020-09-24 21:56:24 +02:00

115 lines
4.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_DEBUGOBJECTS_H
#define _LINUX_DEBUGOBJECTS_H
#include <linux/list.h>
#include <linux/spinlock.h>
enum debug_obj_state {
ODEBUG_STATE_NONE,
ODEBUG_STATE_INIT,
ODEBUG_STATE_INACTIVE,
ODEBUG_STATE_ACTIVE,
ODEBUG_STATE_DESTROYED,
ODEBUG_STATE_NOTAVAILABLE,
ODEBUG_STATE_MAX,
};
struct debug_obj_descr;
/**
* struct debug_obj - representaion of an tracked object
* @node: hlist node to link the object into the tracker list
* @state: tracked object state
* @astate: current active state
* @object: pointer to the real object
* @descr: pointer to an object type specific debug description structure
*/
struct debug_obj {
struct hlist_node node;
enum debug_obj_state state;
unsigned int astate;
void *object;
const struct debug_obj_descr *descr;
};
/**
* struct debug_obj_descr - object type specific debug description structure
*
* @name: name of the object typee
* @debug_hint: function returning address, which have associated
* kernel symbol, to allow identify the object
* @is_static_object: return true if the obj is static, otherwise return false
* @fixup_init: fixup function, which is called when the init check
* fails. All fixup functions must return true if fixup
* was successful, otherwise return false
* @fixup_activate: fixup function, which is called when the activate check
* fails
* @fixup_destroy: fixup function, which is called when the destroy check
* fails
* @fixup_free: fixup function, which is called when the free check
* fails
* @fixup_assert_init: fixup function, which is called when the assert_init
* check fails
*/
struct debug_obj_descr {
const char *name;
void *(*debug_hint)(void *addr);
bool (*is_static_object)(void *addr);
bool (*fixup_init)(void *addr, enum debug_obj_state state);
bool (*fixup_activate)(void *addr, enum debug_obj_state state);
bool (*fixup_destroy)(void *addr, enum debug_obj_state state);
bool (*fixup_free)(void *addr, enum debug_obj_state state);
bool (*fixup_assert_init)(void *addr, enum debug_obj_state state);
};
#ifdef CONFIG_DEBUG_OBJECTS
extern void debug_object_init (void *addr, const struct debug_obj_descr *descr);
extern void
debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr);
extern int debug_object_activate (void *addr, const struct debug_obj_descr *descr);
extern void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr);
extern void debug_object_destroy (void *addr, const struct debug_obj_descr *descr);
extern void debug_object_free (void *addr, const struct debug_obj_descr *descr);
extern void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr);
/*
* Active state:
* - Set at 0 upon initialization.
* - Must return to 0 before deactivation.
*/
extern void
debug_object_active_state(void *addr, const struct debug_obj_descr *descr,
unsigned int expect, unsigned int next);
extern void debug_objects_early_init(void);
extern void debug_objects_mem_init(void);
#else
static inline void
debug_object_init (void *addr, const struct debug_obj_descr *descr) { }
static inline void
debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr) { }
static inline int
debug_object_activate (void *addr, const struct debug_obj_descr *descr) { return 0; }
static inline void
debug_object_deactivate(void *addr, const struct debug_obj_descr *descr) { }
static inline void
debug_object_destroy (void *addr, const struct debug_obj_descr *descr) { }
static inline void
debug_object_free (void *addr, const struct debug_obj_descr *descr) { }
static inline void
debug_object_assert_init(void *addr, const struct debug_obj_descr *descr) { }
static inline void debug_objects_early_init(void) { }
static inline void debug_objects_mem_init(void) { }
#endif
#ifdef CONFIG_DEBUG_OBJECTS_FREE
extern void debug_check_no_obj_freed(const void *address, unsigned long size);
#else
static inline void
debug_check_no_obj_freed(const void *address, unsigned long size) { }
#endif
#endif