11da177e4SLinus Torvalds #ifndef _LINUX_KPROBES_H 21da177e4SLinus Torvalds #define _LINUX_KPROBES_H 31da177e4SLinus Torvalds /* 41da177e4SLinus Torvalds * Kernel Probes (KProbes) 51da177e4SLinus Torvalds * include/linux/kprobes.h 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify 81da177e4SLinus Torvalds * it under the terms of the GNU General Public License as published by 91da177e4SLinus Torvalds * the Free Software Foundation; either version 2 of the License, or 101da177e4SLinus Torvalds * (at your option) any later version. 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds * This program is distributed in the hope that it will be useful, 131da177e4SLinus Torvalds * but WITHOUT ANY WARRANTY; without even the implied warranty of 141da177e4SLinus Torvalds * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 151da177e4SLinus Torvalds * GNU General Public License for more details. 161da177e4SLinus Torvalds * 171da177e4SLinus Torvalds * You should have received a copy of the GNU General Public License 181da177e4SLinus Torvalds * along with this program; if not, write to the Free Software 191da177e4SLinus Torvalds * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 201da177e4SLinus Torvalds * 211da177e4SLinus Torvalds * Copyright (C) IBM Corporation, 2002, 2004 221da177e4SLinus Torvalds * 231da177e4SLinus Torvalds * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel 241da177e4SLinus Torvalds * Probes initial implementation ( includes suggestions from 251da177e4SLinus Torvalds * Rusty Russell). 261da177e4SLinus Torvalds * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes 271da177e4SLinus Torvalds * interface to access function arguments. 28b94cce92SHien Nguyen * 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston 29b94cce92SHien Nguyen * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi 30b94cce92SHien Nguyen * <prasanna@in.ibm.com> added function-return probes. 311da177e4SLinus Torvalds */ 321da177e4SLinus Torvalds #include <linux/config.h> 331da177e4SLinus Torvalds #include <linux/list.h> 341da177e4SLinus Torvalds #include <linux/notifier.h> 351da177e4SLinus Torvalds #include <linux/smp.h> 36b94cce92SHien Nguyen 371da177e4SLinus Torvalds #include <asm/kprobes.h> 381da177e4SLinus Torvalds 39ea32c65cSPrasanna S Panchamukhi /* kprobe_status settings */ 40ea32c65cSPrasanna S Panchamukhi #define KPROBE_HIT_ACTIVE 0x00000001 41ea32c65cSPrasanna S Panchamukhi #define KPROBE_HIT_SS 0x00000002 42ea32c65cSPrasanna S Panchamukhi #define KPROBE_REENTER 0x00000004 43ea32c65cSPrasanna S Panchamukhi #define KPROBE_HIT_SSDONE 0x00000008 44ea32c65cSPrasanna S Panchamukhi 45*d0aaff97SPrasanna S Panchamukhi /* Attach to insert probes on any functions which should be ignored*/ 46*d0aaff97SPrasanna S Panchamukhi #define __kprobes __attribute__((__section__(".kprobes.text"))) 47*d0aaff97SPrasanna S Panchamukhi 481da177e4SLinus Torvalds struct kprobe; 491da177e4SLinus Torvalds struct pt_regs; 50b94cce92SHien Nguyen struct kretprobe; 51b94cce92SHien Nguyen struct kretprobe_instance; 521da177e4SLinus Torvalds typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); 531da177e4SLinus Torvalds typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); 541da177e4SLinus Torvalds typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, 551da177e4SLinus Torvalds unsigned long flags); 561da177e4SLinus Torvalds typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, 571da177e4SLinus Torvalds int trapnr); 58b94cce92SHien Nguyen typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, 59b94cce92SHien Nguyen struct pt_regs *); 60b94cce92SHien Nguyen 611da177e4SLinus Torvalds struct kprobe { 621da177e4SLinus Torvalds struct hlist_node hlist; 631da177e4SLinus Torvalds 6464f562c6SAnanth N Mavinakayanahalli /* list of kprobes for multi-handler support */ 6564f562c6SAnanth N Mavinakayanahalli struct list_head list; 6664f562c6SAnanth N Mavinakayanahalli 67ea32c65cSPrasanna S Panchamukhi /*count the number of times this probe was temporarily disarmed */ 68ea32c65cSPrasanna S Panchamukhi unsigned long nmissed; 69ea32c65cSPrasanna S Panchamukhi 701da177e4SLinus Torvalds /* location of the probe point */ 711da177e4SLinus Torvalds kprobe_opcode_t *addr; 721da177e4SLinus Torvalds 731da177e4SLinus Torvalds /* Called before addr is executed. */ 741da177e4SLinus Torvalds kprobe_pre_handler_t pre_handler; 751da177e4SLinus Torvalds 761da177e4SLinus Torvalds /* Called after addr is executed, unless... */ 771da177e4SLinus Torvalds kprobe_post_handler_t post_handler; 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds /* ... called if executing addr causes a fault (eg. page fault). 801da177e4SLinus Torvalds * Return 1 if it handled fault, otherwise kernel will see it. */ 811da177e4SLinus Torvalds kprobe_fault_handler_t fault_handler; 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds /* ... called if breakpoint trap occurs in probe handler. 841da177e4SLinus Torvalds * Return 1 if it handled break, otherwise kernel will see it. */ 851da177e4SLinus Torvalds kprobe_break_handler_t break_handler; 861da177e4SLinus Torvalds 871da177e4SLinus Torvalds /* Saved opcode (which has been replaced with breakpoint) */ 881da177e4SLinus Torvalds kprobe_opcode_t opcode; 891da177e4SLinus Torvalds 901da177e4SLinus Torvalds /* copy of the original instruction */ 911da177e4SLinus Torvalds struct arch_specific_insn ainsn; 921da177e4SLinus Torvalds }; 931da177e4SLinus Torvalds 941da177e4SLinus Torvalds /* 951da177e4SLinus Torvalds * Special probe type that uses setjmp-longjmp type tricks to resume 961da177e4SLinus Torvalds * execution at a specified entry with a matching prototype corresponding 971da177e4SLinus Torvalds * to the probed function - a trick to enable arguments to become 981da177e4SLinus Torvalds * accessible seamlessly by probe handling logic. 991da177e4SLinus Torvalds * Note: 1001da177e4SLinus Torvalds * Because of the way compilers allocate stack space for local variables 1011da177e4SLinus Torvalds * etc upfront, regardless of sub-scopes within a function, this mirroring 1021da177e4SLinus Torvalds * principle currently works only for probes placed on function entry points. 1031da177e4SLinus Torvalds */ 1041da177e4SLinus Torvalds struct jprobe { 1051da177e4SLinus Torvalds struct kprobe kp; 1061da177e4SLinus Torvalds kprobe_opcode_t *entry; /* probe handling code to jump to */ 1071da177e4SLinus Torvalds }; 1081da177e4SLinus Torvalds 109b94cce92SHien Nguyen #ifdef ARCH_SUPPORTS_KRETPROBES 110b94cce92SHien Nguyen extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs); 111b94cce92SHien Nguyen #else /* ARCH_SUPPORTS_KRETPROBES */ 112b94cce92SHien Nguyen static inline void arch_prepare_kretprobe(struct kretprobe *rp, 113b94cce92SHien Nguyen struct pt_regs *regs) 114b94cce92SHien Nguyen { 115b94cce92SHien Nguyen } 116b94cce92SHien Nguyen #endif /* ARCH_SUPPORTS_KRETPROBES */ 117b94cce92SHien Nguyen /* 118b94cce92SHien Nguyen * Function-return probe - 119b94cce92SHien Nguyen * Note: 120b94cce92SHien Nguyen * User needs to provide a handler function, and initialize maxactive. 121b94cce92SHien Nguyen * maxactive - The maximum number of instances of the probed function that 122b94cce92SHien Nguyen * can be active concurrently. 123b94cce92SHien Nguyen * nmissed - tracks the number of times the probed function's return was 124b94cce92SHien Nguyen * ignored, due to maxactive being too low. 125b94cce92SHien Nguyen * 126b94cce92SHien Nguyen */ 127b94cce92SHien Nguyen struct kretprobe { 128b94cce92SHien Nguyen struct kprobe kp; 129b94cce92SHien Nguyen kretprobe_handler_t handler; 130b94cce92SHien Nguyen int maxactive; 131b94cce92SHien Nguyen int nmissed; 132b94cce92SHien Nguyen struct hlist_head free_instances; 133b94cce92SHien Nguyen struct hlist_head used_instances; 134b94cce92SHien Nguyen }; 135b94cce92SHien Nguyen 136b94cce92SHien Nguyen struct kretprobe_instance { 137b94cce92SHien Nguyen struct hlist_node uflist; /* either on free list or used list */ 138b94cce92SHien Nguyen struct hlist_node hlist; 139b94cce92SHien Nguyen struct kretprobe *rp; 140802eae7cSRusty Lynch kprobe_opcode_t *ret_addr; 141802eae7cSRusty Lynch struct task_struct *task; 142b94cce92SHien Nguyen }; 143b94cce92SHien Nguyen 1441da177e4SLinus Torvalds #ifdef CONFIG_KPROBES 1451da177e4SLinus Torvalds /* Locks kprobe: irq must be disabled */ 1461da177e4SLinus Torvalds void lock_kprobes(void); 1471da177e4SLinus Torvalds void unlock_kprobes(void); 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds /* kprobe running now on this CPU? */ 1501da177e4SLinus Torvalds static inline int kprobe_running(void) 1511da177e4SLinus Torvalds { 1521da177e4SLinus Torvalds extern unsigned int kprobe_cpu; 1531da177e4SLinus Torvalds return kprobe_cpu == smp_processor_id(); 1541da177e4SLinus Torvalds } 1551da177e4SLinus Torvalds 1561da177e4SLinus Torvalds extern int arch_prepare_kprobe(struct kprobe *p); 1571da177e4SLinus Torvalds extern void arch_copy_kprobe(struct kprobe *p); 1587e1048b1SRusty Lynch extern void arch_arm_kprobe(struct kprobe *p); 1597e1048b1SRusty Lynch extern void arch_disarm_kprobe(struct kprobe *p); 1601da177e4SLinus Torvalds extern void arch_remove_kprobe(struct kprobe *p); 1616772926bSRusty Lynch extern int arch_init_kprobes(void); 1621da177e4SLinus Torvalds extern void show_registers(struct pt_regs *regs); 1639ec4b1f3SAnanth N Mavinakayanahalli extern kprobe_opcode_t *get_insn_slot(void); 1649ec4b1f3SAnanth N Mavinakayanahalli extern void free_insn_slot(kprobe_opcode_t *slot); 1651da177e4SLinus Torvalds 1661da177e4SLinus Torvalds /* Get the kprobe at this addr (if any). Must have called lock_kprobes */ 1671da177e4SLinus Torvalds struct kprobe *get_kprobe(void *addr); 168b94cce92SHien Nguyen struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds int register_kprobe(struct kprobe *p); 1711da177e4SLinus Torvalds void unregister_kprobe(struct kprobe *p); 1721da177e4SLinus Torvalds int setjmp_pre_handler(struct kprobe *, struct pt_regs *); 1731da177e4SLinus Torvalds int longjmp_break_handler(struct kprobe *, struct pt_regs *); 1741da177e4SLinus Torvalds int register_jprobe(struct jprobe *p); 1751da177e4SLinus Torvalds void unregister_jprobe(struct jprobe *p); 1761da177e4SLinus Torvalds void jprobe_return(void); 1771da177e4SLinus Torvalds 178b94cce92SHien Nguyen int register_kretprobe(struct kretprobe *rp); 179b94cce92SHien Nguyen void unregister_kretprobe(struct kretprobe *rp); 180b94cce92SHien Nguyen 181b94cce92SHien Nguyen struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp); 182b94cce92SHien Nguyen void add_rp_inst(struct kretprobe_instance *ri); 183b94cce92SHien Nguyen void kprobe_flush_task(struct task_struct *tk); 184b94cce92SHien Nguyen void recycle_rp_inst(struct kretprobe_instance *ri); 185b94cce92SHien Nguyen #else /* CONFIG_KPROBES */ 1861da177e4SLinus Torvalds static inline int kprobe_running(void) 1871da177e4SLinus Torvalds { 1881da177e4SLinus Torvalds return 0; 1891da177e4SLinus Torvalds } 1901da177e4SLinus Torvalds static inline int register_kprobe(struct kprobe *p) 1911da177e4SLinus Torvalds { 1921da177e4SLinus Torvalds return -ENOSYS; 1931da177e4SLinus Torvalds } 1941da177e4SLinus Torvalds static inline void unregister_kprobe(struct kprobe *p) 1951da177e4SLinus Torvalds { 1961da177e4SLinus Torvalds } 1971da177e4SLinus Torvalds static inline int register_jprobe(struct jprobe *p) 1981da177e4SLinus Torvalds { 1991da177e4SLinus Torvalds return -ENOSYS; 2001da177e4SLinus Torvalds } 2011da177e4SLinus Torvalds static inline void unregister_jprobe(struct jprobe *p) 2021da177e4SLinus Torvalds { 2031da177e4SLinus Torvalds } 2041da177e4SLinus Torvalds static inline void jprobe_return(void) 2051da177e4SLinus Torvalds { 2061da177e4SLinus Torvalds } 207b94cce92SHien Nguyen static inline int register_kretprobe(struct kretprobe *rp) 208b94cce92SHien Nguyen { 209b94cce92SHien Nguyen return -ENOSYS; 210b94cce92SHien Nguyen } 211b94cce92SHien Nguyen static inline void unregister_kretprobe(struct kretprobe *rp) 212b94cce92SHien Nguyen { 213b94cce92SHien Nguyen } 214b94cce92SHien Nguyen static inline void kprobe_flush_task(struct task_struct *tk) 215b94cce92SHien Nguyen { 216b94cce92SHien Nguyen } 217b94cce92SHien Nguyen #endif /* CONFIG_KPROBES */ 2181da177e4SLinus Torvalds #endif /* _LINUX_KPROBES_H */ 219