linux/include/linux/kprobes.h
<<
>>
Prefs
   1#ifndef _LINUX_KPROBES_H
   2#define _LINUX_KPROBES_H
   3/*
   4 *  Kernel Probes (KProbes)
   5 *  include/linux/kprobes.h
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20 *
  21 * Copyright (C) IBM Corporation, 2002, 2004
  22 *
  23 * 2002-Oct     Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
  24 *              Probes initial implementation ( includes suggestions from
  25 *              Rusty Russell).
  26 * 2004-July    Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
  27 *              interface to access function arguments.
  28 * 2005-May     Hien Nguyen <hien@us.ibm.com> and Jim Keniston
  29 *              <jkenisto@us.ibm.com>  and Prasanna S Panchamukhi
  30 *              <prasanna@in.ibm.com> added function-return probes.
  31 */
  32#include <linux/linkage.h>
  33#include <linux/list.h>
  34#include <linux/notifier.h>
  35#include <linux/smp.h>
  36#include <linux/bug.h>
  37#include <linux/percpu.h>
  38#include <linux/spinlock.h>
  39#include <linux/rcupdate.h>
  40#include <linux/mutex.h>
  41#include <linux/ftrace.h>
  42
  43#ifdef CONFIG_KPROBES
  44#include <asm/kprobes.h>
  45
  46/* kprobe_status settings */
  47#define KPROBE_HIT_ACTIVE       0x00000001
  48#define KPROBE_HIT_SS           0x00000002
  49#define KPROBE_REENTER          0x00000004
  50#define KPROBE_HIT_SSDONE       0x00000008
  51
  52/* Attach to insert probes on any functions which should be ignored*/
  53#define __kprobes       __attribute__((__section__(".kprobes.text")))
  54
  55#else /* CONFIG_KPROBES */
  56typedef int kprobe_opcode_t;
  57struct arch_specific_insn {
  58        int dummy;
  59};
  60#define __kprobes
  61
  62#endif /* CONFIG_KPROBES */
  63
  64struct kprobe;
  65struct pt_regs;
  66struct kretprobe;
  67struct kretprobe_instance;
  68typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
  69typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
  70typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
  71                                       unsigned long flags);
  72typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
  73                                       int trapnr);
  74typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
  75                                    struct pt_regs *);
  76
  77struct kprobe {
  78        struct hlist_node hlist;
  79
  80        /* list of kprobes for multi-handler support */
  81        struct list_head list;
  82
  83        /*count the number of times this probe was temporarily disarmed */
  84        unsigned long nmissed;
  85
  86        /* location of the probe point */
  87        kprobe_opcode_t *addr;
  88
  89        /* Allow user to indicate symbol name of the probe point */
  90        const char *symbol_name;
  91
  92        /* Offset into the symbol */
  93        unsigned int offset;
  94
  95        /* Called before addr is executed. */
  96        kprobe_pre_handler_t pre_handler;
  97
  98        /* Called after addr is executed, unless... */
  99        kprobe_post_handler_t post_handler;
 100
 101        /*
 102         * ... called if executing addr causes a fault (eg. page fault).
 103         * Return 1 if it handled fault, otherwise kernel will see it.
 104         */
 105        kprobe_fault_handler_t fault_handler;
 106
 107        /*
 108         * ... called if breakpoint trap occurs in probe handler.
 109         * Return 1 if it handled break, otherwise kernel will see it.
 110         */
 111        kprobe_break_handler_t break_handler;
 112
 113        /* Saved opcode (which has been replaced with breakpoint) */
 114        kprobe_opcode_t opcode;
 115
 116        /* copy of the original instruction */
 117        struct arch_specific_insn ainsn;
 118
 119        /*
 120         * Indicates various status flags.
 121         * Protected by kprobe_mutex after this kprobe is registered.
 122         */
 123        u32 flags;
 124};
 125
 126/* Kprobe status flags */
 127#define KPROBE_FLAG_GONE        1 /* breakpoint has already gone */
 128#define KPROBE_FLAG_DISABLED    2 /* probe is temporarily disabled */
 129#define KPROBE_FLAG_OPTIMIZED   4 /*
 130                                   * probe is really optimized.
 131                                   * NOTE:
 132                                   * this flag is only for optimized_kprobe.
 133                                   */
 134#define KPROBE_FLAG_FTRACE      8 /* probe is using ftrace */
 135
 136/* Has this kprobe gone ? */
 137static inline int kprobe_gone(struct kprobe *p)
 138{
 139        return p->flags & KPROBE_FLAG_GONE;
 140}
 141
 142/* Is this kprobe disabled ? */
 143static inline int kprobe_disabled(struct kprobe *p)
 144{
 145        return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
 146}
 147
 148/* Is this kprobe really running optimized path ? */
 149static inline int kprobe_optimized(struct kprobe *p)
 150{
 151        return p->flags & KPROBE_FLAG_OPTIMIZED;
 152}
 153
 154/* Is this kprobe uses ftrace ? */
 155static inline int kprobe_ftrace(struct kprobe *p)
 156{
 157        return p->flags & KPROBE_FLAG_FTRACE;
 158}
 159
 160/*
 161 * Special probe type that uses setjmp-longjmp type tricks to resume
 162 * execution at a specified entry with a matching prototype corresponding
 163 * to the probed function - a trick to enable arguments to become
 164 * accessible seamlessly by probe handling logic.
 165 * Note:
 166 * Because of the way compilers allocate stack space for local variables
 167 * etc upfront, regardless of sub-scopes within a function, this mirroring
 168 * principle currently works only for probes placed on function entry points.
 169 */
 170struct jprobe {
 171        struct kprobe kp;
 172        void *entry;    /* probe handling code to jump to */
 173};
 174
 175/* For backward compatibility with old code using JPROBE_ENTRY() */
 176#define JPROBE_ENTRY(handler)   (handler)
 177
 178/*
 179 * Function-return probe -
 180 * Note:
 181 * User needs to provide a handler function, and initialize maxactive.
 182 * maxactive - The maximum number of instances of the probed function that
 183 * can be active concurrently.
 184 * nmissed - tracks the number of times the probed function's return was
 185 * ignored, due to maxactive being too low.
 186 *
 187 */
 188struct kretprobe {
 189        struct kprobe kp;
 190        kretprobe_handler_t handler;
 191        kretprobe_handler_t entry_handler;
 192        int maxactive;
 193        int nmissed;
 194        size_t data_size;
 195        struct hlist_head free_instances;
 196        raw_spinlock_t lock;
 197};
 198
 199struct kretprobe_instance {
 200        struct hlist_node hlist;
 201        struct kretprobe *rp;
 202        kprobe_opcode_t *ret_addr;
 203        struct task_struct *task;
 204        char data[0];
 205};
 206
 207struct kretprobe_blackpoint {
 208        const char *name;
 209        void *addr;
 210};
 211
 212struct kprobe_blackpoint {
 213        const char *name;
 214        unsigned long start_addr;
 215        unsigned long range;
 216};
 217
 218#ifdef CONFIG_KPROBES
 219DECLARE_PER_CPU(struct kprobe *, current_kprobe);
 220DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 221
 222/*
 223 * For #ifdef avoidance:
 224 */
 225static inline int kprobes_built_in(void)
 226{
 227        return 1;
 228}
 229
 230#ifdef CONFIG_KRETPROBES
 231extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
 232                                   struct pt_regs *regs);
 233extern int arch_trampoline_kprobe(struct kprobe *p);
 234#else /* CONFIG_KRETPROBES */
 235static inline void arch_prepare_kretprobe(struct kretprobe *rp,
 236                                        struct pt_regs *regs)
 237{
 238}
 239static inline int arch_trampoline_kprobe(struct kprobe *p)
 240{
 241        return 0;
 242}
 243#endif /* CONFIG_KRETPROBES */
 244
 245extern struct kretprobe_blackpoint kretprobe_blacklist[];
 246
 247static inline void kretprobe_assert(struct kretprobe_instance *ri,
 248        unsigned long orig_ret_address, unsigned long trampoline_address)
 249{
 250        if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
 251                printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
 252                                ri->rp, ri->rp->kp.addr);
 253                BUG();
 254        }
 255}
 256
 257#ifdef CONFIG_KPROBES_SANITY_TEST
 258extern int init_test_probes(void);
 259#else
 260static inline int init_test_probes(void)
 261{
 262        return 0;
 263}
 264#endif /* CONFIG_KPROBES_SANITY_TEST */
 265
 266extern int arch_prepare_kprobe(struct kprobe *p);
 267extern void arch_arm_kprobe(struct kprobe *p);
 268extern void arch_disarm_kprobe(struct kprobe *p);
 269extern int arch_init_kprobes(void);
 270extern void show_registers(struct pt_regs *regs);
 271extern kprobe_opcode_t *get_insn_slot(void);
 272extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
 273extern void kprobes_inc_nmissed_count(struct kprobe *p);
 274
 275#ifdef CONFIG_OPTPROBES
 276/*
 277 * Internal structure for direct jump optimized probe
 278 */
 279struct optimized_kprobe {
 280        struct kprobe kp;
 281        struct list_head list;  /* list for optimizing queue */
 282        struct arch_optimized_insn optinsn;
 283};
 284
 285/* Architecture dependent functions for direct jump optimization */
 286extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
 287extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
 288extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op);
 289extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
 290extern void arch_optimize_kprobes(struct list_head *oplist);
 291extern void arch_unoptimize_kprobes(struct list_head *oplist,
 292                                    struct list_head *done_list);
 293extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
 294extern kprobe_opcode_t *get_optinsn_slot(void);
 295extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty);
 296extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
 297                                        unsigned long addr);
 298
 299extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
 300
 301#ifdef CONFIG_SYSCTL
 302extern int sysctl_kprobes_optimization;
 303extern int proc_kprobes_optimization_handler(struct ctl_table *table,
 304                                             int write, void __user *buffer,
 305                                             size_t *length, loff_t *ppos);
 306#endif
 307
 308#endif /* CONFIG_OPTPROBES */
 309#ifdef CONFIG_KPROBES_ON_FTRACE
 310extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
 311                                  struct ftrace_ops *ops, struct pt_regs *regs);
 312extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
 313#endif
 314
 315
 316/* Get the kprobe at this addr (if any) - called with preemption disabled */
 317struct kprobe *get_kprobe(void *addr);
 318void kretprobe_hash_lock(struct task_struct *tsk,
 319                         struct hlist_head **head, unsigned long *flags);
 320void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
 321struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
 322
 323/* kprobe_running() will just return the current_kprobe on this CPU */
 324static inline struct kprobe *kprobe_running(void)
 325{
 326        return (__this_cpu_read(current_kprobe));
 327}
 328
 329static inline void reset_current_kprobe(void)
 330{
 331        __this_cpu_write(current_kprobe, NULL);
 332}
 333
 334static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
 335{
 336        return (&__get_cpu_var(kprobe_ctlblk));
 337}
 338
 339int register_kprobe(struct kprobe *p);
 340void unregister_kprobe(struct kprobe *p);
 341int register_kprobes(struct kprobe **kps, int num);
 342void unregister_kprobes(struct kprobe **kps, int num);
 343int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
 344int longjmp_break_handler(struct kprobe *, struct pt_regs *);
 345int register_jprobe(struct jprobe *p);
 346void unregister_jprobe(struct jprobe *p);
 347int register_jprobes(struct jprobe **jps, int num);
 348void unregister_jprobes(struct jprobe **jps, int num);
 349void jprobe_return(void);
 350unsigned long arch_deref_entry_point(void *);
 351
 352int register_kretprobe(struct kretprobe *rp);
 353void unregister_kretprobe(struct kretprobe *rp);
 354int register_kretprobes(struct kretprobe **rps, int num);
 355void unregister_kretprobes(struct kretprobe **rps, int num);
 356
 357void kprobe_flush_task(struct task_struct *tk);
 358void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
 359
 360int disable_kprobe(struct kprobe *kp);
 361int enable_kprobe(struct kprobe *kp);
 362
 363void dump_kprobe(struct kprobe *kp);
 364
 365#else /* !CONFIG_KPROBES: */
 366
 367static inline int kprobes_built_in(void)
 368{
 369        return 0;
 370}
 371static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
 372{
 373        return 0;
 374}
 375static inline struct kprobe *get_kprobe(void *addr)
 376{
 377        return NULL;
 378}
 379static inline struct kprobe *kprobe_running(void)
 380{
 381        return NULL;
 382}
 383static inline int register_kprobe(struct kprobe *p)
 384{
 385        return -ENOSYS;
 386}
 387static inline int register_kprobes(struct kprobe **kps, int num)
 388{
 389        return -ENOSYS;
 390}
 391static inline void unregister_kprobe(struct kprobe *p)
 392{
 393}
 394static inline void unregister_kprobes(struct kprobe **kps, int num)
 395{
 396}
 397static inline int register_jprobe(struct jprobe *p)
 398{
 399        return -ENOSYS;
 400}
 401static inline int register_jprobes(struct jprobe **jps, int num)
 402{
 403        return -ENOSYS;
 404}
 405static inline void unregister_jprobe(struct jprobe *p)
 406{
 407}
 408static inline void unregister_jprobes(struct jprobe **jps, int num)
 409{
 410}
 411static inline void jprobe_return(void)
 412{
 413}
 414static inline int register_kretprobe(struct kretprobe *rp)
 415{
 416        return -ENOSYS;
 417}
 418static inline int register_kretprobes(struct kretprobe **rps, int num)
 419{
 420        return -ENOSYS;
 421}
 422static inline void unregister_kretprobe(struct kretprobe *rp)
 423{
 424}
 425static inline void unregister_kretprobes(struct kretprobe **rps, int num)
 426{
 427}
 428static inline void kprobe_flush_task(struct task_struct *tk)
 429{
 430}
 431static inline int disable_kprobe(struct kprobe *kp)
 432{
 433        return -ENOSYS;
 434}
 435static inline int enable_kprobe(struct kprobe *kp)
 436{
 437        return -ENOSYS;
 438}
 439#endif /* CONFIG_KPROBES */
 440static inline int disable_kretprobe(struct kretprobe *rp)
 441{
 442        return disable_kprobe(&rp->kp);
 443}
 444static inline int enable_kretprobe(struct kretprobe *rp)
 445{
 446        return enable_kprobe(&rp->kp);
 447}
 448static inline int disable_jprobe(struct jprobe *jp)
 449{
 450        return disable_kprobe(&jp->kp);
 451}
 452static inline int enable_jprobe(struct jprobe *jp)
 453{
 454        return enable_kprobe(&jp->kp);
 455}
 456
 457#endif /* _LINUX_KPROBES_H */
 458
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.