include/linux/ftrace.h

   1 /*
   2  * Ftrace header.  For implementation details beyond the random comments
   3  * scattered below, see: Documentation/trace/ftrace-design.txt
   4  */
   5
   6 #ifndef _LINUX_FTRACE_H
   7 #define _LINUX_FTRACE_H
   8
   9 #include <linux/trace_clock.h>
  10 #include <linux/kallsyms.h>
  11 #include <linux/linkage.h>
  12 #include <linux/bitops.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/ktime.h>
  15 #include <linux/sched.h>
  16 #include <linux/types.h>
  17 #include <linux/init.h>
  18 #include <linux/fs.h>
  19
  20 #include <asm/ftrace.h>
  21
  22 /*
  23  * If the arch supports passing the variable contents of
  24  * function_trace_op as the third parameter back from the
  25  * mcount call, then the arch should define this as 1.
  26  */
  27 #ifndef ARCH_SUPPORTS_FTRACE_OPS
  28 #define ARCH_SUPPORTS_FTRACE_OPS 0
  29 #endif
  30
  31 /*
  32  * If the arch's mcount caller does not support all of ftrace's
  33  * features, then it must call an indirect function that
  34  * does. Or at least does enough to prevent any unwelcomed side effects.
  35  */
  36 #if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \
  37         !ARCH_SUPPORTS_FTRACE_OPS
  38 # define FTRACE_FORCE_LIST_FUNC 1
  39 #else
  40 # define FTRACE_FORCE_LIST_FUNC 0
  41 #endif
  42
  43
  44 struct module;
  45 struct ftrace_hash;
  46
  47 #ifdef CONFIG_FUNCTION_TRACER
  48
  49 extern int ftrace_enabled;
  50 extern int
  51 ftrace_enable_sysctl(struct ctl_table *table, int write,
  52                      void __user *buffer, size_t *lenp,
  53                      loff_t *ppos);
  54
  55 struct ftrace_ops;
  56
  57 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
  58                               struct ftrace_ops *op, struct pt_regs *regs);
  59
  60 /*
  61  * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
  62  * set in the flags member.
  63  *
  64  * ENABLED - set/unset when ftrace_ops is registered/unregistered
  65  * GLOBAL  - set manualy by ftrace_ops user to denote the ftrace_ops
  66  *           is part of the global tracers sharing the same filter
  67  *           via set_ftrace_* debugfs files.
  68  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
  69  *           allocated ftrace_ops which need special care
  70  * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
  71  *           could be controled by following calls:
  72  *             ftrace_function_local_enable
  73  *             ftrace_function_local_disable
  74  * SAVE_REGS - The ftrace_ops wants regs saved at each function called
  75  *            and passed to the callback. If this flag is set, but the
  76  *            architecture does not support passing regs
  77  *            (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
  78  *            ftrace_ops will fail to register, unless the next flag
  79  *            is set.
  80  * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
  81  *            handler can handle an arch that does not save regs
  82  *            (the handler tests if regs == NULL), then it can set
  83  *            this flag instead. It will not fail registering the ftrace_ops
  84  *            but, the regs field will be NULL if the arch does not support
  85  *            passing regs to the handler.
  86  *            Note, if this flag is set, the SAVE_REGS flag will automatically
  87  *            get set upon registering the ftrace_ops, if the arch supports it.
  88  * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
  89  *            that the call back has its own recursion protection. If it does
  90  *            not set this, then the ftrace infrastructure will add recursion
  91  *            protection for the caller.
  92  * STUB   - The ftrace_ops is just a place holder.
  93  * INITIALIZED - The ftrace_ops has already been initialized (first use time
  94  *            register_ftrace_function() is called, it will initialized the ops)
  95  */
  96 enum {
  97         FTRACE_OPS_FL_ENABLED                   = 1 << 0,
  98         FTRACE_OPS_FL_GLOBAL                    = 1 << 1,
  99         FTRACE_OPS_FL_DYNAMIC                   = 1 << 2,
 100         FTRACE_OPS_FL_CONTROL                   = 1 << 3,
 101         FTRACE_OPS_FL_SAVE_REGS                 = 1 << 4,
 102         FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED    = 1 << 5,
 103         FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 6,
 104         FTRACE_OPS_FL_STUB                      = 1 << 7,
 105         FTRACE_OPS_FL_INITIALIZED               = 1 << 8,
 106 };
 107
 108 struct ftrace_ops {
 109         ftrace_func_t                   func;
 110         struct ftrace_ops               *next;
 111         unsigned long                   flags;
 112         int __percpu                    *disabled;
 113 #ifdef CONFIG_DYNAMIC_FTRACE
 114         struct ftrace_hash              *notrace_hash;
 115         struct ftrace_hash              *filter_hash;
 116         struct mutex                    regex_lock;
 117 #endif
 118 };
 119
 120 extern int function_trace_stop;
 121
 122 /*
 123  * Type of the current tracing.
 124  */
 125 enum ftrace_tracing_type_t {
 126         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
 127         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
 128 };
 129
 130 /* Current tracing type, default is FTRACE_TYPE_ENTER */
 131 extern enum ftrace_tracing_type_t ftrace_tracing_type;
 132
 133 /**
 134  * ftrace_stop - stop function tracer.
 135  *
 136  * A quick way to stop the function tracer. Note this an on off switch,
 137  * it is not something that is recursive like preempt_disable.
 138  * This does not disable the calling of mcount, it only stops the
 139  * calling of functions from mcount.
 140  */
 141 static inline void ftrace_stop(void)
 142 {
 143         function_trace_stop = 1;
 144 }
 145
 146 /**
 147  * ftrace_start - start the function tracer.
 148  *
 149  * This function is the inverse of ftrace_stop. This does not enable
 150  * the function tracing if the function tracer is disabled. This only
 151  * sets the function tracer flag to continue calling the functions
 152  * from mcount.
 153  */
 154 static inline void ftrace_start(void)
 155 {
 156         function_trace_stop = 0;
 157 }
 158
 159 /*
 160  * The ftrace_ops must be a static and should also
 161  * be read_mostly.  These functions do modify read_mostly variables
 162  * so use them sparely. Never free an ftrace_op or modify the
 163  * next pointer after it has been registered. Even after unregistering
 164  * it, the next pointer may still be used internally.
 165  */
 166 int register_ftrace_function(struct ftrace_ops *ops);
 167 int unregister_ftrace_function(struct ftrace_ops *ops);
 168 void clear_ftrace_function(void);
 169
 170 /**
 171  * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
 172  *
 173  * This function enables tracing on current cpu by decreasing
 174  * the per cpu control variable.
 175  * It must be called with preemption disabled and only on ftrace_ops
 176  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 177  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 178  */
 179 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
 180 {
 181         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 182                 return;
 183
 184         (*this_cpu_ptr(ops->disabled))--;
 185 }
 186
 187 /**
 188  * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
 189  *
 190  * This function enables tracing on current cpu by decreasing
 191  * the per cpu control variable.
 192  * It must be called with preemption disabled and only on ftrace_ops
 193  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 194  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 195  */
 196 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
 197 {
 198         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 199                 return;
 200
 201         (*this_cpu_ptr(ops->disabled))++;
 202 }
 203
 204 /**
 205  * ftrace_function_local_disabled - returns ftrace_ops disabled value
 206  *                                  on current cpu
 207  *
 208  * This function returns value of ftrace_ops::disabled on current cpu.
 209  * It must be called with preemption disabled and only on ftrace_ops
 210  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 211  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 212  */
 213 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
 214 {
 215         WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
 216         return *this_cpu_ptr(ops->disabled);
 217 }
 218
 219 extern void ftrace_stub(unsigned long a0, unsigned long a1,
 220                         struct ftrace_ops *op, struct pt_regs *regs);
 221
 222 #else /* !CONFIG_FUNCTION_TRACER */
 223 /*
 224  * (un)register_ftrace_function must be a macro since the ops parameter
 225  * must not be evaluated.
 226  */
 227 #define register_ftrace_function(ops) ({ 0; })
 228 #define unregister_ftrace_function(ops) ({ 0; })
 229 static inline int ftrace_nr_registered_ops(void)
 230 {
 231         return 0;
 232 }
 233 static inline void clear_ftrace_function(void) { }
 234 static inline void ftrace_kill(void) { }
 235 static inline void ftrace_stop(void) { }
 236 static inline void ftrace_start(void) { }
 237 #endif /* CONFIG_FUNCTION_TRACER */
 238
 239 #ifdef CONFIG_STACK_TRACER
 240 extern int stack_tracer_enabled;
 241 int
 242 stack_trace_sysctl(struct ctl_table *table, int write,
 243                    void __user *buffer, size_t *lenp,
 244                    loff_t *ppos);
 245 #endif
 246
 247 struct ftrace_func_command {
 248         struct list_head        list;
 249         char                    *name;
 250         int                     (*func)(struct ftrace_hash *hash,
 251                                         char *func, char *cmd,
 252                                         char *params, int enable);
 253 };
 254
 255 #ifdef CONFIG_DYNAMIC_FTRACE
 256
 257 int ftrace_arch_code_modify_prepare(void);
 258 int ftrace_arch_code_modify_post_process(void);
 259
 260 void ftrace_bug(int err, unsigned long ip);
 261
 262 struct seq_file;
 263
 264 struct ftrace_probe_ops {
 265         void                    (*func)(unsigned long ip,
 266                                         unsigned long parent_ip,
 267                                         void **data);
 268         int                     (*init)(struct ftrace_probe_ops *ops,
 269                                         unsigned long ip, void **data);
 270         void                    (*free)(struct ftrace_probe_ops *ops,
 271                                         unsigned long ip, void **data);
 272         int                     (*print)(struct seq_file *m,
 273                                          unsigned long ip,
 274                                          struct ftrace_probe_ops *ops,
 275                                          void *data);
 276 };
 277
 278 extern int
 279 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 280                               void *data);
 281 extern void
 282 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 283                                 void *data);
 284 extern void
 285 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 286 extern void unregister_ftrace_function_probe_all(char *glob);
 287
 288 extern int ftrace_text_reserved(void *start, void *end);
 289
 290 extern int ftrace_nr_registered_ops(void);
 291
 292 /*
 293  * The dyn_ftrace record's flags field is split into two parts.
 294  * the first part which is '0-FTRACE_REF_MAX' is a counter of
 295  * the number of callbacks that have registered the function that
 296  * the dyn_ftrace descriptor represents.
 297  *
 298  * The second part is a mask:
 299  *  ENABLED - the function is being traced
 300  *  REGS    - the record wants the function to save regs
 301  *  REGS_EN - the function is set up to save regs.
 302  *
 303  * When a new ftrace_ops is registered and wants a function to save
 304  * pt_regs, the rec->flag REGS is set. When the function has been
 305  * set up to save regs, the REG_EN flag is set. Once a function
 306  * starts saving regs it will do so until all ftrace_ops are removed
 307  * from tracing that function.
 308  */
 309 enum {
 310         FTRACE_FL_ENABLED       = (1UL << 29),
 311         FTRACE_FL_REGS          = (1UL << 30),
 312         FTRACE_FL_REGS_EN       = (1UL << 31)
 313 };
 314
 315 #define FTRACE_FL_MASK          (0x7UL << 29)
 316 #define FTRACE_REF_MAX          ((1UL << 29) - 1)
 317
 318 struct dyn_ftrace {
 319         union {
 320                 unsigned long           ip; /* address of mcount call-site */
 321                 struct dyn_ftrace       *freelist;
 322         };
 323         unsigned long           flags;
 324         struct dyn_arch_ftrace          arch;
 325 };
 326
 327 int ftrace_force_update(void);
 328 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 329                          int remove, int reset);
 330 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 331                        int len, int reset);
 332 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 333                         int len, int reset);
 334 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 335 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 336 void ftrace_free_filter(struct ftrace_ops *ops);
 337
 338 int register_ftrace_command(struct ftrace_func_command *cmd);
 339 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 340
 341 enum {
 342         FTRACE_UPDATE_CALLS             = (1 << 0),
 343         FTRACE_DISABLE_CALLS            = (1 << 1),
 344         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
 345         FTRACE_START_FUNC_RET           = (1 << 3),
 346         FTRACE_STOP_FUNC_RET            = (1 << 4),
 347 };
 348
 349 /*
 350  * The FTRACE_UPDATE_* enum is used to pass information back
 351  * from the ftrace_update_record() and ftrace_test_record()
 352  * functions. These are called by the code update routines
 353  * to find out what is to be done for a given function.
 354  *
 355  *  IGNORE           - The function is already what we want it to be
 356  *  MAKE_CALL        - Start tracing the function
 357  *  MODIFY_CALL      - Stop saving regs for the function
 358  *  MODIFY_CALL_REGS - Start saving regs for the function
 359  *  MAKE_NOP         - Stop tracing the function
 360  */
 361 enum {
 362         FTRACE_UPDATE_IGNORE,
 363         FTRACE_UPDATE_MAKE_CALL,
 364         FTRACE_UPDATE_MODIFY_CALL,
 365         FTRACE_UPDATE_MODIFY_CALL_REGS,
 366         FTRACE_UPDATE_MAKE_NOP,
 367 };
 368
 369 enum {
 370         FTRACE_ITER_FILTER      = (1 << 0),
 371         FTRACE_ITER_NOTRACE     = (1 << 1),
 372         FTRACE_ITER_PRINTALL    = (1 << 2),
 373         FTRACE_ITER_DO_HASH     = (1 << 3),
 374         FTRACE_ITER_HASH        = (1 << 4),
 375         FTRACE_ITER_ENABLED     = (1 << 5),
 376 };
 377
 378 void arch_ftrace_update_code(int command);
 379
 380 struct ftrace_rec_iter;
 381
 382 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
 383 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
 384 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
 385
 386 #define for_ftrace_rec_iter(iter)               \
 387         for (iter = ftrace_rec_iter_start();    \
 388              iter;                              \
 389              iter = ftrace_rec_iter_next(iter))
 390
 391
 392 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
 393 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
 394 void ftrace_run_stop_machine(int command);
 395 unsigned long ftrace_location(unsigned long ip);
 396
 397 extern ftrace_func_t ftrace_trace_function;
 398
 399 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
 400                   struct inode *inode, struct file *file);
 401 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 402                             size_t cnt, loff_t *ppos);
 403 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 404                              size_t cnt, loff_t *ppos);
 405 int ftrace_regex_release(struct inode *inode, struct file *file);
 406
 407 void __init
 408 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
 409
 410 /* defined in arch */
 411 extern int ftrace_ip_converted(unsigned long ip);
 412 extern int ftrace_dyn_arch_init(void *data);
 413 extern void ftrace_replace_code(int enable);
 414 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 415 extern void ftrace_caller(void);
 416 extern void ftrace_regs_caller(void);
 417 extern void ftrace_call(void);
 418 extern void ftrace_regs_call(void);
 419 extern void mcount_call(void);
 420
 421 void ftrace_modify_all_code(int command);
 422
 423 #ifndef FTRACE_ADDR
 424 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 425 #endif
 426
 427 #ifndef FTRACE_REGS_ADDR
 428 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 429 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
 430 #else
 431 # define FTRACE_REGS_ADDR FTRACE_ADDR
 432 #endif
 433 #endif
 434
 435 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 436 extern void ftrace_graph_caller(void);
 437 extern int ftrace_enable_ftrace_graph_caller(void);
 438 extern int ftrace_disable_ftrace_graph_caller(void);
 439 #else
 440 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 441 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 442 #endif
 443
 444 /**
 445  * ftrace_make_nop - convert code into nop
 446  * @mod: module structure if called by module load initialization
 447  * @rec: the mcount call site record
 448  * @addr: the address that the call site should be calling
 449  *
 450  * This is a very sensitive operation and great care needs
 451  * to be taken by the arch.  The operation should carefully
 452  * read the location, check to see if what is read is indeed
 453  * what we expect it to be, and then on success of the compare,
 454  * it should write to the location.
 455  *
 456  * The code segment at @rec->ip should be a caller to @addr
 457  *
 458  * Return must be:
 459  *  0 on success
 460  *  -EFAULT on error reading the location
 461  *  -EINVAL on a failed compare of the contents
 462  *  -EPERM  on error writing to the location
 463  * Any other value will be considered a failure.
 464  */
 465 extern int ftrace_make_nop(struct module *mod,
 466                            struct dyn_ftrace *rec, unsigned long addr);
 467
 468 /**
 469  * ftrace_make_call - convert a nop call site into a call to addr
 470  * @rec: the mcount call site record
 471  * @addr: the address that the call site should call
 472  *
 473  * This is a very sensitive operation and great care needs
 474  * to be taken by the arch.  The operation should carefully
 475  * read the location, check to see if what is read is indeed
 476  * what we expect it to be, and then on success of the compare,
 477  * it should write to the location.
 478  *
 479  * The code segment at @rec->ip should be a nop
 480  *
 481  * Return must be:
 482  *  0 on success
 483  *  -EFAULT on error reading the location
 484  *  -EINVAL on a failed compare of the contents
 485  *  -EPERM  on error writing to the location
 486  * Any other value will be considered a failure.
 487  */
 488 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 489
 490 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 491 /**
 492  * ftrace_modify_call - convert from one addr to another (no nop)
 493  * @rec: the mcount call site record
 494  * @old_addr: the address expected to be currently called to
 495  * @addr: the address to change to
 496  *
 497  * This is a very sensitive operation and great care needs
 498  * to be taken by the arch.  The operation should carefully
 499  * read the location, check to see if what is read is indeed
 500  * what we expect it to be, and then on success of the compare,
 501  * it should write to the location.
 502  *
 503  * The code segment at @rec->ip should be a caller to @old_addr
 504  *
 505  * Return must be:
 506  *  0 on success
 507  *  -EFAULT on error reading the location
 508  *  -EINVAL on a failed compare of the contents
 509  *  -EPERM  on error writing to the location
 510  * Any other value will be considered a failure.
 511  */
 512 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 513                               unsigned long addr);
 514 #else
 515 /* Should never be called */
 516 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 517                                      unsigned long addr)
 518 {
 519         return -EINVAL;
 520 }
 521 #endif
 522
 523 /* May be defined in arch */
 524 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 525
 526 extern int skip_trace(unsigned long ip);
 527 extern void ftrace_module_init(struct module *mod);
 528
 529 extern void ftrace_disable_daemon(void);
 530 extern void ftrace_enable_daemon(void);
 531 #else /* CONFIG_DYNAMIC_FTRACE */
 532 static inline int skip_trace(unsigned long ip) { return 0; }
 533 static inline int ftrace_force_update(void) { return 0; }
 534 static inline void ftrace_disable_daemon(void) { }
 535 static inline void ftrace_enable_daemon(void) { }
 536 static inline void ftrace_release_mod(struct module *mod) {}
 537 static inline void ftrace_module_init(struct module *mod) {}
 538 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
 539 {
 540         return -EINVAL;
 541 }
 542 static inline int unregister_ftrace_command(char *cmd_name)
 543 {
 544         return -EINVAL;
 545 }
 546 static inline int ftrace_text_reserved(void *start, void *end)
 547 {
 548         return 0;
 549 }
 550 static inline unsigned long ftrace_location(unsigned long ip)
 551 {
 552         return 0;
 553 }
 554
 555 /*
 556  * Again users of functions that have ftrace_ops may not
 557  * have them defined when ftrace is not enabled, but these
 558  * functions may still be called. Use a macro instead of inline.
 559  */
 560 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
 561 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
 562 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
 563 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
 564 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
 565 #define ftrace_free_filter(ops) do { } while (0)
 566
 567 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 568                             size_t cnt, loff_t *ppos) { return -ENODEV; }
 569 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 570                              size_t cnt, loff_t *ppos) { return -ENODEV; }
 571 static inline loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int whence)
 572 {
 573         return -ENODEV;
 574 }
 575 static inline int
 576 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
 577 #endif /* CONFIG_DYNAMIC_FTRACE */
 578
 579 loff_t ftrace_filter_lseek(struct file *file, loff_t offset, int whence);
 580
 581 /* totally disable ftrace - can not re-enable after this */
 582 void ftrace_kill(void);
 583
 584 static inline void tracer_disable(void)
 585 {
 586 #ifdef CONFIG_FUNCTION_TRACER
 587         ftrace_enabled = 0;
 588 #endif
 589 }
 590
 591 /*
 592  * Ftrace disable/restore without lock. Some synchronization mechanism
 593  * must be used to prevent ftrace_enabled to be changed between
 594  * disable/restore.
 595  */
 596 static inline int __ftrace_enabled_save(void)
 597 {
 598 #ifdef CONFIG_FUNCTION_TRACER
 599         int saved_ftrace_enabled = ftrace_enabled;
 600         ftrace_enabled = 0;
 601         return saved_ftrace_enabled;
 602 #else
 603         return 0;
 604 #endif
 605 }
 606
 607 static inline void __ftrace_enabled_restore(int enabled)
 608 {
 609 #ifdef CONFIG_FUNCTION_TRACER
 610         ftrace_enabled = enabled;
 611 #endif
 612 }
 613
 614 #ifndef HAVE_ARCH_CALLER_ADDR
 615 # ifdef CONFIG_FRAME_POINTER
 616 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 617 #  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 618 #  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 619 #  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 620 #  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 621 #  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 622 #  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 623 # else
 624 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 625 #  define CALLER_ADDR1 0UL
 626 #  define CALLER_ADDR2 0UL
 627 #  define CALLER_ADDR3 0UL
 628 #  define CALLER_ADDR4 0UL
 629 #  define CALLER_ADDR5 0UL
 630 #  define CALLER_ADDR6 0UL
 631 # endif
 632 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
 633
 634 #ifdef CONFIG_IRQSOFF_TRACER
 635   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 636   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 637 #else
 638   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
 639   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
 640 #endif
 641
 642 #ifdef CONFIG_PREEMPT_TRACER
 643   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 644   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 645 #else
 646 /*
 647  * Use defines instead of static inlines because some arches will make code out
 648  * of the CALLER_ADDR, when we really want these to be a real nop.
 649  */
 650 # define trace_preempt_on(a0, a1) do { } while (0)
 651 # define trace_preempt_off(a0, a1) do { } while (0)
 652 #endif
 653
 654 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 655 extern void ftrace_init(void);
 656 #else
 657 static inline void ftrace_init(void) { }
 658 #endif
 659
 660 /*
 661  * Structure that defines an entry function trace.
 662  */
 663 struct ftrace_graph_ent {
 664         unsigned long func; /* Current function */
 665         int depth;
 666 };
 667
 668 /*
 669  * Structure that defines a return function trace.
 670  */
 671 struct ftrace_graph_ret {
 672         unsigned long func; /* Current function */
 673         unsigned long long calltime;
 674         unsigned long long rettime;
 675         /* Number of functions that overran the depth limit for current task */
 676         unsigned long overrun;
 677         int depth;
 678 };
 679
 680 /* Type of the callback handlers for tracing function graph*/
 681 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 682 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 683
 684 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 685
 686 /* for init task */
 687 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
 688
 689 /*
 690  * Stack of return addresses for functions
 691  * of a thread.
 692  * Used in struct thread_info
 693  */
 694 struct ftrace_ret_stack {
 695         unsigned long ret;
 696         unsigned long func;
 697         unsigned long long calltime;
 698         unsigned long long subtime;
 699         unsigned long fp;
 700 };
 701
 702 /*
 703  * Primary handler of a function return.
 704  * It relays on ftrace_return_to_handler.
 705  * Defined in entry_32/64.S
 706  */
 707 extern void return_to_handler(void);
 708
 709 extern int
 710 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 711                          unsigned long frame_pointer);
 712
 713 /*
 714  * Sometimes we don't want to trace a function with the function
 715  * graph tracer but we want them to keep traced by the usual function
 716  * tracer if the function graph tracer is not configured.
 717  */
 718 #define __notrace_funcgraph             notrace
 719
 720 /*
 721  * We want to which function is an entrypoint of a hardirq.
 722  * That will help us to put a signal on output.
 723  */
 724 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 725
 726 /* Limits of hardirq entrypoints */
 727 extern char __irqentry_text_start[];
 728 extern char __irqentry_text_end[];
 729
 730 #define FTRACE_RETFUNC_DEPTH 50
 731 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 732 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 733                                 trace_func_graph_ent_t entryfunc);
 734
 735 extern void ftrace_graph_stop(void);
 736
 737 /* The current handlers in use */
 738 extern trace_func_graph_ret_t ftrace_graph_return;
 739 extern trace_func_graph_ent_t ftrace_graph_entry;
 740
 741 extern void unregister_ftrace_graph(void);
 742
 743 extern void ftrace_graph_init_task(struct task_struct *t);
 744 extern void ftrace_graph_exit_task(struct task_struct *t);
 745 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
 746
 747 static inline int task_curr_ret_stack(struct task_struct *t)
 748 {
 749         return t->curr_ret_stack;
 750 }
 751
 752 static inline void pause_graph_tracing(void)
 753 {
 754         atomic_inc(&current->tracing_graph_pause);
 755 }
 756
 757 static inline void unpause_graph_tracing(void)
 758 {
 759         atomic_dec(&current->tracing_graph_pause);
 760 }
 761 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 762
 763 #define __notrace_funcgraph
 764 #define __irq_entry
 765 #define INIT_FTRACE_GRAPH
 766
 767 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 768 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 769 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
 770
 771 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 772                           trace_func_graph_ent_t entryfunc)
 773 {
 774         return -1;
 775 }
 776 static inline void unregister_ftrace_graph(void) { }
 777
 778 static inline int task_curr_ret_stack(struct task_struct *tsk)
 779 {
 780         return -1;
 781 }
 782
 783 static inline void pause_graph_tracing(void) { }
 784 static inline void unpause_graph_tracing(void) { }
 785 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 786
 787 #ifdef CONFIG_TRACING
 788
 789 /* flags for current->trace */
 790 enum {
 791         TSK_TRACE_FL_TRACE_BIT  = 0,
 792         TSK_TRACE_FL_GRAPH_BIT  = 1,
 793 };
 794 enum {
 795         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 796         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 797 };
 798
 799 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 800 {
 801         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 802 }
 803
 804 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 805 {
 806         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 807 }
 808
 809 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 810 {
 811         return tsk->trace & TSK_TRACE_FL_TRACE;
 812 }
 813
 814 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 815 {
 816         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 817 }
 818
 819 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 820 {
 821         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 822 }
 823
 824 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 825 {
 826         return tsk->trace & TSK_TRACE_FL_GRAPH;
 827 }
 828
 829 enum ftrace_dump_mode;
 830
 831 extern enum ftrace_dump_mode ftrace_dump_on_oops;
 832
 833 #ifdef CONFIG_PREEMPT
 834 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
 835 #endif
 836
 837 #endif /* CONFIG_TRACING */
 838
 839 #ifndef INIT_TRACE_RECURSION
 840 #define INIT_TRACE_RECURSION
 841 #endif
 842
 843 #ifdef CONFIG_FTRACE_SYSCALLS
 844
 845 unsigned long arch_syscall_addr(int nr);
 846
 847 #endif /* CONFIG_FTRACE_SYSCALLS */
 848
 849 #endif /* _LINUX_FTRACE_H */