#ifndef _LINUX_KPROBES_H #define _LINUX_KPROBES_H /* * Kernel Probes (KProbes) * include/linux/kprobes.h * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Copyright (C) IBM Corporation, 2002, 2004 * * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel * Probes initial implementation ( includes suggestions from * 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/linkage.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> #include <linux/mutex.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"))) #else /* CONFIG_KPROBES */ typedef int kprobe_opcode_t; struct arch_specific_insn { int dummy; }; #define __kprobes #endif /* CONFIG_KPROBES */ 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; /*count the number of times this probe was temporarily disarmed */ unsigned long nmissed; /* location of the probe point */ kprobe_opcode_t *addr; /* Allow user to indicate symbol name of the probe point */ const char *symbol_name; /* Offset into the symbol */ unsigned int offset; /* Called before addr is executed. */ kprobe_pre_handler_t pre_handler; /* Called after addr is executed, unless... */ kprobe_post_handler_t post_handler; /* * ... called if executing addr causes a fault (eg. page fault). * Return 1 if it handled fault, otherwise kernel will see it. */ kprobe_fault_handler_t fault_handler; /* * ... called if breakpoint trap occurs in probe handler. * Return 1 if it handled break, otherwise kernel will see it. */ kprobe_break_handler_t break_handler; /* Saved opcode (which has been replaced with breakpoint) */ kprobe_opcode_t opcode; /* copy of the original instruction */ struct arch_specific_insn ainsn; /* * Indicates various status flags. * Protected by kprobe_mutex after this kprobe is registered. */ u32 flags; }; /* Kprobe status flags */ #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */ #define KPROBE_FLAG_OPTIMIZED 4 /* * probe is really optimized. * NOTE: * this flag is only for optimized_kprobe. */ /* Has this kprobe gone ? */ static inline int kprobe_gone(struct kprobe *p) { return p->flags & KPROBE_FLAG_GONE; } /* Is this kprobe disabled ? */ static inline int kprobe_disabled(struct kprobe *p) { return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE); } /* Is this kprobe really running optimized path ? */ static inline int kprobe_optimized(struct kprobe *p) { return p->flags & KPROBE_FLAG_OPTIMIZED; } /* * Special probe type that uses setjmp-longjmp type tricks to resume * execution at a specified entry with a matching prototype corresponding * to the probed function - a trick to enable arguments to become * accessible seamlessly by probe handling logic. * Note: * Because of the way compilers allocate stack space for local variables * etc upfront, regardless of sub-scopes within a function, this mirroring * principle currently works only for probes placed on function entry points. */ struct jprobe { struct kprobe kp; void *entry; /* probe handling code to jump to */ }; /* For backward compatibility with old code using JPROBE_ENTRY() */ #define JPROBE_ENTRY(handler) (handler) /* * 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; kretprobe_handler_t entry_handler; int maxactive; int nmissed; size_t data_size; struct hlist_head free_instances; spinlock_t lock; }; struct kretprobe_instance { struct hlist_node hlist; struct kretprobe *rp; kprobe_opcode_t *ret_addr; struct task_struct *task; char data[0]; }; struct kretprobe_blackpoint { const char *name; void *addr; }; struct kprobe_blackpoint { const char *name; unsigned long start_addr; unsigned long range; }; #ifdef CONFIG_KPROBES DECLARE_PER_CPU(struct kprobe *, current_kprobe); DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); /* * For #ifdef avoidance: */ static inline int kprobes_built_in(void) { return 1; } #ifdef CONFIG_KRETPROBES extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs); extern int arch_trampoline_kprobe(struct kprobe *p); #else /* CONFIG_KRETPROBES */ static inline void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs) { } static inline int arch_trampoline_kprobe(struct kprobe *p) { return 0; } #endif /* CONFIG_KRETPROBES */ extern struct kretprobe_blackpoint kretprobe_blacklist[]; static inline void kretprobe_assert(struct kretprobe_instance *ri, unsigned long orig_ret_address, unsigned long trampoline_address) { if (!orig_ret_address || (orig_ret_address == trampoline_address)) { printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", ri->rp, ri->rp->kp.addr); BUG(); } } #ifdef CONFIG_KPROBES_SANITY_TEST extern int init_test_probes(void); #else static inline int init_test_probes(void) { return 0; } #endif /* CONFIG_KPROBES_SANITY_TEST */ extern int arch_prepare_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, int dirty); extern void kprobes_inc_nmissed_count(struct kprobe *p); #ifdef CONFIG_OPTPROBES /* * Internal structure for direct jump optimized probe */ struct optimized_kprobe { struct kprobe kp; struct list_head list; /* list for optimizing queue */ struct arch_optimized_insn optinsn; }; /* Architecture dependent functions for direct jump optimization */ extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn); extern int arch_check_optimized_kprobe(struct optimized_kprobe *op); extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op); extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op); extern int arch_optimize_kprobe(struct optimized_kprobe *op); extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); extern kprobe_opcode_t *get_optinsn_slot(void); extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty); extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, unsigned long addr); extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); #ifdef CONFIG_SYSCTL extern int sysctl_kprobes_optimization; extern int proc_kprobes_optimization_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos); #endif #endif /* CONFIG_OPTPROBES */ /* Get the kprobe at this addr (if any) - called with preemption disabled */ struct kprobe *get_kprobe(void *addr); void kretprobe_hash_lock(struct task_struct *tsk, struct hlist_head **head, unsigned long *flags); void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); 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); int register_kprobes(struct kprobe **kps, int num); void unregister_kprobes(struct kprobe **kps, int num); int setjmp_pre_handler(struct kprobe *, struct pt_regs *); int longjmp_break_handler(struct kprobe *, struct pt_regs *); int register_jprobe(struct jprobe *p); void unregister_jprobe(struct jprobe *p); int register_jprobes(struct jprobe **jps, int num); void unregister_jprobes(struct jprobe **jps, int num); void jprobe_return(void); unsigned long arch_deref_entry_point(void *); int register_kretprobe(struct kretprobe *rp); void unregister_kretprobe(struct kretprobe *rp); int register_kretprobes(struct kretprobe **rps, int num); void unregister_kretprobes(struct kretprobe **rps, int num); void kprobe_flush_task(struct task_struct *tk); void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); int disable_kprobe(struct kprobe *kp); int enable_kprobe(struct kprobe *kp); void dump_kprobe(struct kprobe *kp); #else /* !CONFIG_KPROBES: */ static inline int kprobes_built_in(void) { return 0; } static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) { return 0; } static inline struct kprobe *get_kprobe(void *addr) { return NULL; } static inline struct kprobe *kprobe_running(void) { return NULL; } static inline int register_kprobe(struct kprobe *p) { return -ENOSYS; } static inline int register_kprobes(struct kprobe **kps, int num) { return -ENOSYS; } static inline void unregister_kprobe(struct kprobe *p) { } static inline void unregister_kprobes(struct kprobe **kps, int num) { } static inline int register_jprobe(struct jprobe *p) { return -ENOSYS; } static inline int register_jprobes(struct jprobe **jps, int num) { return -ENOSYS; } static inline void unregister_jprobe(struct jprobe *p) { } static inline void unregister_jprobes(struct jprobe **jps, int num) { } static inline void jprobe_return(void) { } static inline int register_kretprobe(struct kretprobe *rp) { return -ENOSYS; } static inline int register_kretprobes(struct kretprobe **rps, int num) { return -ENOSYS; } static inline void unregister_kretprobe(struct kretprobe *rp) { } static inline void unregister_kretprobes(struct kretprobe **rps, int num) { } static inline void kprobe_flush_task(struct task_struct *tk) { } static inline int disable_kprobe(struct kprobe *kp) { return -ENOSYS; } static inline int enable_kprobe(struct kprobe *kp) { return -ENOSYS; } #endif /* CONFIG_KPROBES */ static inline int disable_kretprobe(struct kretprobe *rp) { return disable_kprobe(&rp->kp); } static inline int enable_kretprobe(struct kretprobe *rp) { return enable_kprobe(&rp->kp); } static inline int disable_jprobe(struct jprobe *jp) { return disable_kprobe(&jp->kp); } static inline int enable_jprobe(struct jprobe *jp) { return enable_kprobe(&jp->kp); } #endif /* _LINUX_KPROBES_H */