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