* Rusty Russell).
* 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
* interface to access function arguments.
+ * 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston
+ * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
+ * <prasanna@in.ibm.com> added function-return probes.
*/
#include <linux/config.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/smp.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+
+#ifdef CONFIG_KPROBES
#include <asm/kprobes.h>
+/* kprobe_status settings */
+#define KPROBE_HIT_ACTIVE 0x00000001
+#define KPROBE_HIT_SS 0x00000002
+#define KPROBE_REENTER 0x00000004
+#define KPROBE_HIT_SSDONE 0x00000008
+
+/* Attach to insert probes on any functions which should be ignored*/
+#define __kprobes __attribute__((__section__(".kprobes.text")))
+
struct kprobe;
struct pt_regs;
+struct kretprobe;
+struct kretprobe_instance;
typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
unsigned long flags);
typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
int trapnr);
+typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
+ struct pt_regs *);
+
struct kprobe {
struct hlist_node hlist;
/* list of kprobes for multi-handler support */
struct list_head list;
+ /* Indicates that the corresponding module has been ref counted */
+ unsigned int mod_refcounted;
+
+ /*count the number of times this probe was temporarily disarmed */
+ unsigned long nmissed;
+
/* location of the probe point */
kprobe_opcode_t *addr;
kprobe_opcode_t *entry; /* probe handling code to jump to */
};
-#ifdef CONFIG_KPROBES
-/* Locks kprobe: irq must be disabled */
-void lock_kprobes(void);
-void unlock_kprobes(void);
+DECLARE_PER_CPU(struct kprobe *, current_kprobe);
+DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
-/* kprobe running now on this CPU? */
-static inline int kprobe_running(void)
+#ifdef ARCH_SUPPORTS_KRETPROBES
+extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
+#else /* ARCH_SUPPORTS_KRETPROBES */
+static inline void arch_prepare_kretprobe(struct kretprobe *rp,
+ struct pt_regs *regs)
{
- extern unsigned int kprobe_cpu;
- return kprobe_cpu == smp_processor_id();
}
+#endif /* ARCH_SUPPORTS_KRETPROBES */
+/*
+ * Function-return probe -
+ * Note:
+ * User needs to provide a handler function, and initialize maxactive.
+ * maxactive - The maximum number of instances of the probed function that
+ * can be active concurrently.
+ * nmissed - tracks the number of times the probed function's return was
+ * ignored, due to maxactive being too low.
+ *
+ */
+struct kretprobe {
+ struct kprobe kp;
+ kretprobe_handler_t handler;
+ int maxactive;
+ int nmissed;
+ struct hlist_head free_instances;
+ struct hlist_head used_instances;
+};
+struct kretprobe_instance {
+ struct hlist_node uflist; /* either on free list or used list */
+ struct hlist_node hlist;
+ struct kretprobe *rp;
+ kprobe_opcode_t *ret_addr;
+ struct task_struct *task;
+};
+
+extern spinlock_t kretprobe_lock;
+extern struct semaphore kprobe_mutex;
extern int arch_prepare_kprobe(struct kprobe *p);
-extern void arch_copy_kprobe(struct kprobe *p);
-extern void arch_remove_kprobe(struct kprobe *p);
+extern void arch_arm_kprobe(struct kprobe *p);
+extern void arch_disarm_kprobe(struct kprobe *p);
+extern int arch_init_kprobes(void);
extern void show_registers(struct pt_regs *regs);
+extern kprobe_opcode_t *get_insn_slot(void);
+extern void free_insn_slot(kprobe_opcode_t *slot);
+extern void kprobes_inc_nmissed_count(struct kprobe *p);
-/* Get the kprobe at this addr (if any). Must have called lock_kprobes */
+/* Get the kprobe at this addr (if any) - called with preemption disabled */
struct kprobe *get_kprobe(void *addr);
+struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
+
+/* kprobe_running() will just return the current_kprobe on this CPU */
+static inline struct kprobe *kprobe_running(void)
+{
+ return (__get_cpu_var(current_kprobe));
+}
+
+static inline void reset_current_kprobe(void)
+{
+ __get_cpu_var(current_kprobe) = NULL;
+}
+
+static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
+{
+ return (&__get_cpu_var(kprobe_ctlblk));
+}
int register_kprobe(struct kprobe *p);
void unregister_kprobe(struct kprobe *p);
void unregister_jprobe(struct jprobe *p);
void jprobe_return(void);
-#else
-static inline int kprobe_running(void)
+int register_kretprobe(struct kretprobe *rp);
+void unregister_kretprobe(struct kretprobe *rp);
+
+struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
+void add_rp_inst(struct kretprobe_instance *ri);
+void kprobe_flush_task(struct task_struct *tk);
+void recycle_rp_inst(struct kretprobe_instance *ri);
+#else /* CONFIG_KPROBES */
+
+#define __kprobes /**/
+struct jprobe;
+struct kretprobe;
+
+static inline struct kprobe *kprobe_running(void)
{
- return 0;
+ return NULL;
}
static inline int register_kprobe(struct kprobe *p)
{
static inline void jprobe_return(void)
{
}
-#endif
+static inline int register_kretprobe(struct kretprobe *rp)
+{
+ return -ENOSYS;
+}
+static inline void unregister_kretprobe(struct kretprobe *rp)
+{
+}
+static inline void kprobe_flush_task(struct task_struct *tk)
+{
+}
+#endif /* CONFIG_KPROBES */
#endif /* _LINUX_KPROBES_H */