a5d8e467f8
Implement a basic state machine checker in the debugobjects. This state machine checker detects races and inconsistencies within the "active" life of a debugobject. The checker only keeps track of the current state; all the state machine logic is kept at the object instance level. The checker works by adding a supplementary "unsigned int astate" field to the debug_obj structure. It keeps track of the current "active state" of the object. The only constraints that are imposed on the states by the debugobjects system is that: - activation of an object sets the current active state to 0, - deactivation of an object expects the current active state to be 0. For the rest of the states, the state mapping is determined by the specific object instance. Therefore, the logic keeping track of the state machine is within the specialized instance, without any need to know about it at the debugobject level. The current object active state is changed by calling: debug_object_active_state(addr, descr, expect, next) where "expect" is the expected state and "next" is the next state to move to if the expected state is found. A warning is generated if the expected is not found. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David S. Miller <davem@davemloft.net> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: akpm@linux-foundation.org CC: mingo@elte.hu CC: laijs@cn.fujitsu.com CC: dipankar@in.ibm.com CC: josh@joshtriplett.org CC: dvhltc@us.ibm.com CC: niv@us.ibm.com CC: peterz@infradead.org CC: rostedt@goodmis.org CC: Valdis.Kletnieks@vt.edu CC: dhowells@redhat.com CC: eric.dumazet@gmail.com CC: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
101 lines
3.2 KiB
C
101 lines
3.2 KiB
C
#ifndef _LINUX_DEBUGOBJECTS_H
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#define _LINUX_DEBUGOBJECTS_H
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#include <linux/list.h>
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#include <linux/spinlock.h>
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enum debug_obj_state {
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ODEBUG_STATE_NONE,
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ODEBUG_STATE_INIT,
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ODEBUG_STATE_INACTIVE,
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ODEBUG_STATE_ACTIVE,
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ODEBUG_STATE_DESTROYED,
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ODEBUG_STATE_NOTAVAILABLE,
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ODEBUG_STATE_MAX,
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};
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struct debug_obj_descr;
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/**
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* struct debug_obj - representaion of an tracked object
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* @node: hlist node to link the object into the tracker list
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* @state: tracked object state
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* @astate: current active state
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* @object: pointer to the real object
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* @descr: pointer to an object type specific debug description structure
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*/
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struct debug_obj {
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struct hlist_node node;
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enum debug_obj_state state;
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unsigned int astate;
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void *object;
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struct debug_obj_descr *descr;
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};
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/**
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* struct debug_obj_descr - object type specific debug description structure
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* @name: name of the object typee
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* @fixup_init: fixup function, which is called when the init check
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* fails
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* @fixup_activate: fixup function, which is called when the activate check
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* fails
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* @fixup_destroy: fixup function, which is called when the destroy check
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* fails
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* @fixup_free: fixup function, which is called when the free check
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* fails
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*/
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struct debug_obj_descr {
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const char *name;
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int (*fixup_init) (void *addr, enum debug_obj_state state);
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int (*fixup_activate) (void *addr, enum debug_obj_state state);
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int (*fixup_destroy) (void *addr, enum debug_obj_state state);
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int (*fixup_free) (void *addr, enum debug_obj_state state);
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};
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#ifdef CONFIG_DEBUG_OBJECTS
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extern void debug_object_init (void *addr, struct debug_obj_descr *descr);
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extern void
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debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr);
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extern void debug_object_activate (void *addr, struct debug_obj_descr *descr);
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extern void debug_object_deactivate(void *addr, struct debug_obj_descr *descr);
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extern void debug_object_destroy (void *addr, struct debug_obj_descr *descr);
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extern void debug_object_free (void *addr, struct debug_obj_descr *descr);
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/*
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* Active state:
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* - Set at 0 upon initialization.
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* - Must return to 0 before deactivation.
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*/
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extern void
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debug_object_active_state(void *addr, struct debug_obj_descr *descr,
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unsigned int expect, unsigned int next);
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extern void debug_objects_early_init(void);
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extern void debug_objects_mem_init(void);
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#else
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static inline void
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debug_object_init (void *addr, struct debug_obj_descr *descr) { }
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static inline void
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debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) { }
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static inline void
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debug_object_activate (void *addr, struct debug_obj_descr *descr) { }
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static inline void
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debug_object_deactivate(void *addr, struct debug_obj_descr *descr) { }
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static inline void
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debug_object_destroy (void *addr, struct debug_obj_descr *descr) { }
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static inline void
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debug_object_free (void *addr, struct debug_obj_descr *descr) { }
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static inline void debug_objects_early_init(void) { }
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static inline void debug_objects_mem_init(void) { }
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#endif
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#ifdef CONFIG_DEBUG_OBJECTS_FREE
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extern void debug_check_no_obj_freed(const void *address, unsigned long size);
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#else
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static inline void
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debug_check_no_obj_freed(const void *address, unsigned long size) { }
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#endif
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#endif
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