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Diffstat (limited to 'include/linux/kprobes.h')
| -rw-r--r-- | include/linux/kprobes.h | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h new file mode 100644 index 00000000..dd7c12e8 --- /dev/null +++ b/include/linux/kprobes.h @@ -0,0 +1,439 @@ +#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 void arch_optimize_kprobes(struct list_head *oplist); +extern void arch_unoptimize_kprobes(struct list_head *oplist, + struct list_head *done_list); +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 (__this_cpu_read(current_kprobe)); +} + +static inline void reset_current_kprobe(void) +{ + __this_cpu_write(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 */ |