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 !ARCH_SUPPORTS_FTRACE_OPS
  37 # define FTRACE_FORCE_LIST_FUNC 1
  38 #else
  39 # define FTRACE_FORCE_LIST_FUNC 0
  40 #endif
  41
  42
  43 struct module;
  44 struct ftrace_hash;
  45
  46 #ifdef CONFIG_FUNCTION_TRACER
  47
  48 extern int ftrace_enabled;
  49 extern int
  50 ftrace_enable_sysctl(struct ctl_table *table, int write,
  51                      void __user *buffer, size_t *lenp,
  52                      loff_t *ppos);
  53
  54 struct ftrace_ops;
  55
  56 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
  57                               struct ftrace_ops *op, struct pt_regs *regs);
  58
  59 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
  60
  61 /*
  62  * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
  63  * set in the flags member.
  64  *
  65  * ENABLED - set/unset when ftrace_ops is registered/unregistered
  66  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
  67  *           allocated ftrace_ops which need special care
  68  * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
  69  *           could be controled by following calls:
  70  *             ftrace_function_local_enable
  71  *             ftrace_function_local_disable
  72  * SAVE_REGS - The ftrace_ops wants regs saved at each function called
  73  *            and passed to the callback. If this flag is set, but the
  74  *            architecture does not support passing regs
  75  *            (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
  76  *            ftrace_ops will fail to register, unless the next flag
  77  *            is set.
  78  * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
  79  *            handler can handle an arch that does not save regs
  80  *            (the handler tests if regs == NULL), then it can set
  81  *            this flag instead. It will not fail registering the ftrace_ops
  82  *            but, the regs field will be NULL if the arch does not support
  83  *            passing regs to the handler.
  84  *            Note, if this flag is set, the SAVE_REGS flag will automatically
  85  *            get set upon registering the ftrace_ops, if the arch supports it.
  86  * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
  87  *            that the call back has its own recursion protection. If it does
  88  *            not set this, then the ftrace infrastructure will add recursion
  89  *            protection for the caller.
  90  * STUB   - The ftrace_ops is just a place holder.
  91  * INITIALIZED - The ftrace_ops has already been initialized (first use time
  92  *            register_ftrace_function() is called, it will initialized the ops)
  93  * DELETED - The ops are being deleted, do not let them be registered again.
  94  * ADDING  - The ops is in the process of being added.
  95  * REMOVING - The ops is in the process of being removed.
  96  * MODIFYING - The ops is in the process of changing its filter functions.
  97  */
  98 enum {
  99         FTRACE_OPS_FL_ENABLED                   = 1 << 0,
 100         FTRACE_OPS_FL_DYNAMIC                   = 1 << 1,
 101         FTRACE_OPS_FL_CONTROL                   = 1 << 2,
 102         FTRACE_OPS_FL_SAVE_REGS                 = 1 << 3,
 103         FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED    = 1 << 4,
 104         FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 5,
 105         FTRACE_OPS_FL_STUB                      = 1 << 6,
 106         FTRACE_OPS_FL_INITIALIZED               = 1 << 7,
 107         FTRACE_OPS_FL_DELETED                   = 1 << 8,
 108         FTRACE_OPS_FL_ADDING                    = 1 << 9,
 109         FTRACE_OPS_FL_REMOVING                  = 1 << 10,
 110         FTRACE_OPS_FL_MODIFYING                 = 1 << 11,
 111 };
 112
 113 #ifdef CONFIG_DYNAMIC_FTRACE
 114 /* The hash used to know what functions callbacks trace */
 115 struct ftrace_ops_hash {
 116         struct ftrace_hash              *notrace_hash;
 117         struct ftrace_hash              *filter_hash;
 118         struct mutex                    regex_lock;
 119 };
 120 #endif
 121
 122 /*
 123  * Note, ftrace_ops can be referenced outside of RCU protection.
 124  * (Although, for perf, the control ops prevent that). If ftrace_ops is
 125  * allocated and not part of kernel core data, the unregistering of it will
 126  * perform a scheduling on all CPUs to make sure that there are no more users.
 127  * Depending on the load of the system that may take a bit of time.
 128  *
 129  * Any private data added must also take care not to be freed and if private
 130  * data is added to a ftrace_ops that is in core code, the user of the
 131  * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
 132  */
 133 struct ftrace_ops {
 134         ftrace_func_t                   func;
 135         struct ftrace_ops               *next;
 136         unsigned long                   flags;
 137         void                            *private;
 138         int __percpu                    *disabled;
 139 #ifdef CONFIG_DYNAMIC_FTRACE
 140         int                             nr_trampolines;
 141         struct ftrace_ops_hash          local_hash;
 142         struct ftrace_ops_hash          *func_hash;
 143         struct ftrace_ops_hash          old_hash;
 144         unsigned long                   trampoline;
 145 #endif
 146 };
 147
 148 /*
 149  * Type of the current tracing.
 150  */
 151 enum ftrace_tracing_type_t {
 152         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
 153         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
 154 };
 155
 156 /* Current tracing type, default is FTRACE_TYPE_ENTER */
 157 extern enum ftrace_tracing_type_t ftrace_tracing_type;
 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 #endif /* CONFIG_FUNCTION_TRACER */
 236
 237 #ifdef CONFIG_STACK_TRACER
 238 extern int stack_tracer_enabled;
 239 int
 240 stack_trace_sysctl(struct ctl_table *table, int write,
 241                    void __user *buffer, size_t *lenp,
 242                    loff_t *ppos);
 243 #endif
 244
 245 struct ftrace_func_command {
 246         struct list_head        list;
 247         char                    *name;
 248         int                     (*func)(struct ftrace_hash *hash,
 249                                         char *func, char *cmd,
 250                                         char *params, int enable);
 251 };
 252
 253 #ifdef CONFIG_DYNAMIC_FTRACE
 254
 255 int ftrace_arch_code_modify_prepare(void);
 256 int ftrace_arch_code_modify_post_process(void);
 257
 258 void ftrace_bug(int err, unsigned long ip);
 259
 260 struct seq_file;
 261
 262 struct ftrace_probe_ops {
 263         void                    (*func)(unsigned long ip,
 264                                         unsigned long parent_ip,
 265                                         void **data);
 266         int                     (*init)(struct ftrace_probe_ops *ops,
 267                                         unsigned long ip, void **data);
 268         void                    (*free)(struct ftrace_probe_ops *ops,
 269                                         unsigned long ip, void **data);
 270         int                     (*print)(struct seq_file *m,
 271                                          unsigned long ip,
 272                                          struct ftrace_probe_ops *ops,
 273                                          void *data);
 274 };
 275
 276 extern int
 277 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 278                               void *data);
 279 extern void
 280 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 281                                 void *data);
 282 extern void
 283 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 284 extern void unregister_ftrace_function_probe_all(char *glob);
 285
 286 extern int ftrace_text_reserved(const void *start, const void *end);
 287
 288 extern int ftrace_nr_registered_ops(void);
 289
 290 /*
 291  * The dyn_ftrace record's flags field is split into two parts.
 292  * the first part which is '0-FTRACE_REF_MAX' is a counter of
 293  * the number of callbacks that have registered the function that
 294  * the dyn_ftrace descriptor represents.
 295  *
 296  * The second part is a mask:
 297  *  ENABLED - the function is being traced
 298  *  REGS    - the record wants the function to save regs
 299  *  REGS_EN - the function is set up to save regs.
 300  *
 301  * When a new ftrace_ops is registered and wants a function to save
 302  * pt_regs, the rec->flag REGS is set. When the function has been
 303  * set up to save regs, the REG_EN flag is set. Once a function
 304  * starts saving regs it will do so until all ftrace_ops are removed
 305  * from tracing that function.
 306  */
 307 enum {
 308         FTRACE_FL_ENABLED       = (1UL << 31),
 309         FTRACE_FL_REGS          = (1UL << 30),
 310         FTRACE_FL_REGS_EN       = (1UL << 29),
 311         FTRACE_FL_TRAMP         = (1UL << 28),
 312         FTRACE_FL_TRAMP_EN      = (1UL << 27),
 313 };
 314
 315 #define FTRACE_REF_MAX_SHIFT    27
 316 #define FTRACE_FL_BITS          5
 317 #define FTRACE_FL_MASKED_BITS   ((1UL << FTRACE_FL_BITS) - 1)
 318 #define FTRACE_FL_MASK          (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
 319 #define FTRACE_REF_MAX          ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
 320
 321 #define ftrace_rec_count(rec)   ((rec)->flags & ~FTRACE_FL_MASK)
 322
 323 struct dyn_ftrace {
 324         unsigned long           ip; /* address of mcount call-site */
 325         unsigned long           flags;
 326         struct dyn_arch_ftrace  arch;
 327 };
 328
 329 int ftrace_force_update(void);
 330 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 331                          int remove, int reset);
 332 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 333                        int len, int reset);
 334 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 335                         int len, int reset);
 336 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 337 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 338 void ftrace_free_filter(struct ftrace_ops *ops);
 339
 340 int register_ftrace_command(struct ftrace_func_command *cmd);
 341 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 342
 343 enum {
 344         FTRACE_UPDATE_CALLS             = (1 << 0),
 345         FTRACE_DISABLE_CALLS            = (1 << 1),
 346         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
 347         FTRACE_START_FUNC_RET           = (1 << 3),
 348         FTRACE_STOP_FUNC_RET            = (1 << 4),
 349 };
 350
 351 /*
 352  * The FTRACE_UPDATE_* enum is used to pass information back
 353  * from the ftrace_update_record() and ftrace_test_record()
 354  * functions. These are called by the code update routines
 355  * to find out what is to be done for a given function.
 356  *
 357  *  IGNORE           - The function is already what we want it to be
 358  *  MAKE_CALL        - Start tracing the function
 359  *  MODIFY_CALL      - Stop saving regs for the function
 360  *  MAKE_NOP         - Stop tracing the function
 361  */
 362 enum {
 363         FTRACE_UPDATE_IGNORE,
 364         FTRACE_UPDATE_MAKE_CALL,
 365         FTRACE_UPDATE_MODIFY_CALL,
 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 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
 397 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
 398
 399 extern ftrace_func_t ftrace_trace_function;
 400
 401 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
 402                   struct inode *inode, struct file *file);
 403 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 404                             size_t cnt, loff_t *ppos);
 405 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 406                              size_t cnt, loff_t *ppos);
 407 int ftrace_regex_release(struct inode *inode, struct file *file);
 408
 409 void __init
 410 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
 411
 412 /* defined in arch */
 413 extern int ftrace_ip_converted(unsigned long ip);
 414 extern int ftrace_dyn_arch_init(void);
 415 extern void ftrace_replace_code(int enable);
 416 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 417 extern void ftrace_caller(void);
 418 extern void ftrace_regs_caller(void);
 419 extern void ftrace_call(void);
 420 extern void ftrace_regs_call(void);
 421 extern void mcount_call(void);
 422
 423 void ftrace_modify_all_code(int command);
 424
 425 #ifndef FTRACE_ADDR
 426 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 427 #endif
 428
 429 #ifndef FTRACE_GRAPH_ADDR
 430 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
 431 #endif
 432
 433 #ifndef FTRACE_REGS_ADDR
 434 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 435 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
 436 #else
 437 # define FTRACE_REGS_ADDR FTRACE_ADDR
 438 #endif
 439 #endif
 440
 441 /*
 442  * If an arch would like functions that are only traced
 443  * by the function graph tracer to jump directly to its own
 444  * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
 445  * to be that address to jump to.
 446  */
 447 #ifndef FTRACE_GRAPH_TRAMP_ADDR
 448 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
 449 #endif
 450
 451 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 452 extern void ftrace_graph_caller(void);
 453 extern int ftrace_enable_ftrace_graph_caller(void);
 454 extern int ftrace_disable_ftrace_graph_caller(void);
 455 #else
 456 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 457 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 458 #endif
 459
 460 /**
 461  * ftrace_make_nop - convert code into nop
 462  * @mod: module structure if called by module load initialization
 463  * @rec: the mcount call site record
 464  * @addr: the address that the call site should be calling
 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 caller to @addr
 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_nop(struct module *mod,
 482                            struct dyn_ftrace *rec, unsigned long addr);
 483
 484 /**
 485  * ftrace_make_call - convert a nop call site into a call to addr
 486  * @rec: the mcount call site record
 487  * @addr: the address that the call site should call
 488  *
 489  * This is a very sensitive operation and great care needs
 490  * to be taken by the arch.  The operation should carefully
 491  * read the location, check to see if what is read is indeed
 492  * what we expect it to be, and then on success of the compare,
 493  * it should write to the location.
 494  *
 495  * The code segment at @rec->ip should be a nop
 496  *
 497  * Return must be:
 498  *  0 on success
 499  *  -EFAULT on error reading the location
 500  *  -EINVAL on a failed compare of the contents
 501  *  -EPERM  on error writing to the location
 502  * Any other value will be considered a failure.
 503  */
 504 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 505
 506 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 507 /**
 508  * ftrace_modify_call - convert from one addr to another (no nop)
 509  * @rec: the mcount call site record
 510  * @old_addr: the address expected to be currently called to
 511  * @addr: the address to change to
 512  *
 513  * This is a very sensitive operation and great care needs
 514  * to be taken by the arch.  The operation should carefully
 515  * read the location, check to see if what is read is indeed
 516  * what we expect it to be, and then on success of the compare,
 517  * it should write to the location.
 518  *
 519  * The code segment at @rec->ip should be a caller to @old_addr
 520  *
 521  * Return must be:
 522  *  0 on success
 523  *  -EFAULT on error reading the location
 524  *  -EINVAL on a failed compare of the contents
 525  *  -EPERM  on error writing to the location
 526  * Any other value will be considered a failure.
 527  */
 528 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 529                               unsigned long addr);
 530 #else
 531 /* Should never be called */
 532 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 533                                      unsigned long addr)
 534 {
 535         return -EINVAL;
 536 }
 537 #endif
 538
 539 /* May be defined in arch */
 540 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 541
 542 extern int skip_trace(unsigned long ip);
 543 extern void ftrace_module_init(struct module *mod);
 544
 545 extern void ftrace_disable_daemon(void);
 546 extern void ftrace_enable_daemon(void);
 547 #else /* CONFIG_DYNAMIC_FTRACE */
 548 static inline int skip_trace(unsigned long ip) { return 0; }
 549 static inline int ftrace_force_update(void) { return 0; }
 550 static inline void ftrace_disable_daemon(void) { }
 551 static inline void ftrace_enable_daemon(void) { }
 552 static inline void ftrace_release_mod(struct module *mod) {}
 553 static inline void ftrace_module_init(struct module *mod) {}
 554 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
 555 {
 556         return -EINVAL;
 557 }
 558 static inline __init int unregister_ftrace_command(char *cmd_name)
 559 {
 560         return -EINVAL;
 561 }
 562 static inline int ftrace_text_reserved(const void *start, const void *end)
 563 {
 564         return 0;
 565 }
 566 static inline unsigned long ftrace_location(unsigned long ip)
 567 {
 568         return 0;
 569 }
 570
 571 /*
 572  * Again users of functions that have ftrace_ops may not
 573  * have them defined when ftrace is not enabled, but these
 574  * functions may still be called. Use a macro instead of inline.
 575  */
 576 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
 577 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
 578 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
 579 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
 580 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
 581 #define ftrace_free_filter(ops) do { } while (0)
 582
 583 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 584                             size_t cnt, loff_t *ppos) { return -ENODEV; }
 585 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 586                              size_t cnt, loff_t *ppos) { return -ENODEV; }
 587 static inline int
 588 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
 589 #endif /* CONFIG_DYNAMIC_FTRACE */
 590
 591 /* totally disable ftrace - can not re-enable after this */
 592 void ftrace_kill(void);
 593
 594 static inline void tracer_disable(void)
 595 {
 596 #ifdef CONFIG_FUNCTION_TRACER
 597         ftrace_enabled = 0;
 598 #endif
 599 }
 600
 601 /*
 602  * Ftrace disable/restore without lock. Some synchronization mechanism
 603  * must be used to prevent ftrace_enabled to be changed between
 604  * disable/restore.
 605  */
 606 static inline int __ftrace_enabled_save(void)
 607 {
 608 #ifdef CONFIG_FUNCTION_TRACER
 609         int saved_ftrace_enabled = ftrace_enabled;
 610         ftrace_enabled = 0;
 611         return saved_ftrace_enabled;
 612 #else
 613         return 0;
 614 #endif
 615 }
 616
 617 static inline void __ftrace_enabled_restore(int enabled)
 618 {
 619 #ifdef CONFIG_FUNCTION_TRACER
 620         ftrace_enabled = enabled;
 621 #endif
 622 }
 623
 624 /* All archs should have this, but we define it for consistency */
 625 #ifndef ftrace_return_address0
 626 # define ftrace_return_address0 __builtin_return_address(0)
 627 #endif
 628
 629 /* Archs may use other ways for ADDR1 and beyond */
 630 #ifndef ftrace_return_address
 631 # ifdef CONFIG_FRAME_POINTER
 632 #  define ftrace_return_address(n) __builtin_return_address(n)
 633 # else
 634 #  define ftrace_return_address(n) 0UL
 635 # endif
 636 #endif
 637
 638 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
 639 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
 640 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
 641 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
 642 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
 643 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
 644 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
 645
 646 #ifdef CONFIG_IRQSOFF_TRACER
 647   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 648   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 649 #else
 650   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
 651   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
 652 #endif
 653
 654 #ifdef CONFIG_PREEMPT_TRACER
 655   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 656   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 657 #else
 658 /*
 659  * Use defines instead of static inlines because some arches will make code out
 660  * of the CALLER_ADDR, when we really want these to be a real nop.
 661  */
 662 # define trace_preempt_on(a0, a1) do { } while (0)
 663 # define trace_preempt_off(a0, a1) do { } while (0)
 664 #endif
 665
 666 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 667 extern void ftrace_init(void);
 668 #else
 669 static inline void ftrace_init(void) { }
 670 #endif
 671
 672 /*
 673  * Structure that defines an entry function trace.
 674  */
 675 struct ftrace_graph_ent {
 676         unsigned long func; /* Current function */
 677         int depth;
 678 };
 679
 680 /*
 681  * Structure that defines a return function trace.
 682  */
 683 struct ftrace_graph_ret {
 684         unsigned long func; /* Current function */
 685         unsigned long long calltime;
 686         unsigned long long rettime;
 687         /* Number of functions that overran the depth limit for current task */
 688         unsigned long overrun;
 689         int depth;
 690 };
 691
 692 /* Type of the callback handlers for tracing function graph*/
 693 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 694 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 695
 696 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 697
 698 /* for init task */
 699 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
 700
 701 /*
 702  * Stack of return addresses for functions
 703  * of a thread.
 704  * Used in struct thread_info
 705  */
 706 struct ftrace_ret_stack {
 707         unsigned long ret;
 708         unsigned long func;
 709         unsigned long long calltime;
 710         unsigned long long subtime;
 711         unsigned long fp;
 712 };
 713
 714 /*
 715  * Primary handler of a function return.
 716  * It relays on ftrace_return_to_handler.
 717  * Defined in entry_32/64.S
 718  */
 719 extern void return_to_handler(void);
 720
 721 extern int
 722 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 723                          unsigned long frame_pointer);
 724
 725 /*
 726  * Sometimes we don't want to trace a function with the function
 727  * graph tracer but we want them to keep traced by the usual function
 728  * tracer if the function graph tracer is not configured.
 729  */
 730 #define __notrace_funcgraph             notrace
 731
 732 /*
 733  * We want to which function is an entrypoint of a hardirq.
 734  * That will help us to put a signal on output.
 735  */
 736 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 737
 738 /* Limits of hardirq entrypoints */
 739 extern char __irqentry_text_start[];
 740 extern char __irqentry_text_end[];
 741
 742 #define FTRACE_NOTRACE_DEPTH 65536
 743 #define FTRACE_RETFUNC_DEPTH 50
 744 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 745 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 746                                 trace_func_graph_ent_t entryfunc);
 747
 748 extern bool ftrace_graph_is_dead(void);
 749 extern void ftrace_graph_stop(void);
 750
 751 /* The current handlers in use */
 752 extern trace_func_graph_ret_t ftrace_graph_return;
 753 extern trace_func_graph_ent_t ftrace_graph_entry;
 754
 755 extern void unregister_ftrace_graph(void);
 756
 757 extern void ftrace_graph_init_task(struct task_struct *t);
 758 extern void ftrace_graph_exit_task(struct task_struct *t);
 759 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
 760
 761 static inline int task_curr_ret_stack(struct task_struct *t)
 762 {
 763         return t->curr_ret_stack;
 764 }
 765
 766 static inline void pause_graph_tracing(void)
 767 {
 768         atomic_inc(&current->tracing_graph_pause);
 769 }
 770
 771 static inline void unpause_graph_tracing(void)
 772 {
 773         atomic_dec(&current->tracing_graph_pause);
 774 }
 775 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 776
 777 #define __notrace_funcgraph
 778 #define __irq_entry
 779 #define INIT_FTRACE_GRAPH
 780
 781 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 782 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 783 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
 784
 785 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 786                           trace_func_graph_ent_t entryfunc)
 787 {
 788         return -1;
 789 }
 790 static inline void unregister_ftrace_graph(void) { }
 791
 792 static inline int task_curr_ret_stack(struct task_struct *tsk)
 793 {
 794         return -1;
 795 }
 796
 797 static inline void pause_graph_tracing(void) { }
 798 static inline void unpause_graph_tracing(void) { }
 799 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 800
 801 #ifdef CONFIG_TRACING
 802
 803 /* flags for current->trace */
 804 enum {
 805         TSK_TRACE_FL_TRACE_BIT  = 0,
 806         TSK_TRACE_FL_GRAPH_BIT  = 1,
 807 };
 808 enum {
 809         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 810         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 811 };
 812
 813 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 814 {
 815         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 816 }
 817
 818 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 819 {
 820         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 821 }
 822
 823 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 824 {
 825         return tsk->trace & TSK_TRACE_FL_TRACE;
 826 }
 827
 828 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 829 {
 830         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 831 }
 832
 833 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 834 {
 835         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 836 }
 837
 838 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 839 {
 840         return tsk->trace & TSK_TRACE_FL_GRAPH;
 841 }
 842
 843 enum ftrace_dump_mode;
 844
 845 extern enum ftrace_dump_mode ftrace_dump_on_oops;
 846
 847 extern void disable_trace_on_warning(void);
 848 extern int __disable_trace_on_warning;
 849
 850 #ifdef CONFIG_PREEMPT
 851 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
 852 #endif
 853
 854 #else /* CONFIG_TRACING */
 855 static inline void  disable_trace_on_warning(void) { }
 856 #endif /* CONFIG_TRACING */
 857
 858 #ifndef INIT_TRACE_RECURSION
 859 #define INIT_TRACE_RECURSION
 860 #endif
 861
 862 #ifdef CONFIG_FTRACE_SYSCALLS
 863
 864 unsigned long arch_syscall_addr(int nr);
 865
 866 #endif /* CONFIG_FTRACE_SYSCALLS */
 867
 868 #endif /* _LINUX_FTRACE_H */