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  * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
  98  *            The arch specific code sets this flag when it allocated a
  99  *            trampoline. This lets the arch know that it can update the
 100  *            trampoline in case the callback function changes.
 101  *            The ftrace_ops trampoline can be set by the ftrace users, and
 102  *            in such cases the arch must not modify it. Only the arch ftrace
 103  *            core code should set this flag.
 104  */
 105 enum {
 106         FTRACE_OPS_FL_ENABLED                   = 1 << 0,
 107         FTRACE_OPS_FL_DYNAMIC                   = 1 << 1,
 108         FTRACE_OPS_FL_CONTROL                   = 1 << 2,
 109         FTRACE_OPS_FL_SAVE_REGS                 = 1 << 3,
 110         FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED    = 1 << 4,
 111         FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 5,
 112         FTRACE_OPS_FL_STUB                      = 1 << 6,
 113         FTRACE_OPS_FL_INITIALIZED               = 1 << 7,
 114         FTRACE_OPS_FL_DELETED                   = 1 << 8,
 115         FTRACE_OPS_FL_ADDING                    = 1 << 9,
 116         FTRACE_OPS_FL_REMOVING                  = 1 << 10,
 117         FTRACE_OPS_FL_MODIFYING                 = 1 << 11,
 118         FTRACE_OPS_FL_ALLOC_TRAMP               = 1 << 12,
 119 };
 120
 121 #ifdef CONFIG_DYNAMIC_FTRACE
 122 /* The hash used to know what functions callbacks trace */
 123 struct ftrace_ops_hash {
 124         struct ftrace_hash              *notrace_hash;
 125         struct ftrace_hash              *filter_hash;
 126         struct mutex                    regex_lock;
 127 };
 128 #endif
 129
 130 /*
 131  * Note, ftrace_ops can be referenced outside of RCU protection.
 132  * (Although, for perf, the control ops prevent that). If ftrace_ops is
 133  * allocated and not part of kernel core data, the unregistering of it will
 134  * perform a scheduling on all CPUs to make sure that there are no more users.
 135  * Depending on the load of the system that may take a bit of time.
 136  *
 137  * Any private data added must also take care not to be freed and if private
 138  * data is added to a ftrace_ops that is in core code, the user of the
 139  * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
 140  */
 141 struct ftrace_ops {
 142         ftrace_func_t                   func;
 143         struct ftrace_ops               *next;
 144         unsigned long                   flags;
 145         void                            *private;
 146         int __percpu                    *disabled;
 147 #ifdef CONFIG_DYNAMIC_FTRACE
 148         int                             nr_trampolines;
 149         struct ftrace_ops_hash          local_hash;
 150         struct ftrace_ops_hash          *func_hash;
 151         struct ftrace_ops_hash          old_hash;
 152         unsigned long                   trampoline;
 153         unsigned long                   trampoline_size;
 154 #endif
 155 };
 156
 157 /*
 158  * Type of the current tracing.
 159  */
 160 enum ftrace_tracing_type_t {
 161         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
 162         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
 163 };
 164
 165 /* Current tracing type, default is FTRACE_TYPE_ENTER */
 166 extern enum ftrace_tracing_type_t ftrace_tracing_type;
 167
 168 /*
 169  * The ftrace_ops must be a static and should also
 170  * be read_mostly.  These functions do modify read_mostly variables
 171  * so use them sparely. Never free an ftrace_op or modify the
 172  * next pointer after it has been registered. Even after unregistering
 173  * it, the next pointer may still be used internally.
 174  */
 175 int register_ftrace_function(struct ftrace_ops *ops);
 176 int unregister_ftrace_function(struct ftrace_ops *ops);
 177 void clear_ftrace_function(void);
 178
 179 /**
 180  * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
 181  *
 182  * This function enables tracing on current cpu by decreasing
 183  * the per cpu control variable.
 184  * It must be called with preemption disabled and only on ftrace_ops
 185  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 186  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 187  */
 188 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
 189 {
 190         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 191                 return;
 192
 193         (*this_cpu_ptr(ops->disabled))--;
 194 }
 195
 196 /**
 197  * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
 198  *
 199  * This function enables tracing on current cpu by decreasing
 200  * the per cpu control variable.
 201  * It must be called with preemption disabled and only on ftrace_ops
 202  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 203  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 204  */
 205 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
 206 {
 207         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 208                 return;
 209
 210         (*this_cpu_ptr(ops->disabled))++;
 211 }
 212
 213 /**
 214  * ftrace_function_local_disabled - returns ftrace_ops disabled value
 215  *                                  on current cpu
 216  *
 217  * This function returns value of ftrace_ops::disabled on current cpu.
 218  * It must be called with preemption disabled and only on ftrace_ops
 219  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 220  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 221  */
 222 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
 223 {
 224         WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
 225         return *this_cpu_ptr(ops->disabled);
 226 }
 227
 228 extern void ftrace_stub(unsigned long a0, unsigned long a1,
 229                         struct ftrace_ops *op, struct pt_regs *regs);
 230
 231 #else /* !CONFIG_FUNCTION_TRACER */
 232 /*
 233  * (un)register_ftrace_function must be a macro since the ops parameter
 234  * must not be evaluated.
 235  */
 236 #define register_ftrace_function(ops) ({ 0; })
 237 #define unregister_ftrace_function(ops) ({ 0; })
 238 static inline int ftrace_nr_registered_ops(void)
 239 {
 240         return 0;
 241 }
 242 static inline void clear_ftrace_function(void) { }
 243 static inline void ftrace_kill(void) { }
 244 #endif /* CONFIG_FUNCTION_TRACER */
 245
 246 #ifdef CONFIG_STACK_TRACER
 247 extern int stack_tracer_enabled;
 248 int
 249 stack_trace_sysctl(struct ctl_table *table, int write,
 250                    void __user *buffer, size_t *lenp,
 251                    loff_t *ppos);
 252 #endif
 253
 254 struct ftrace_func_command {
 255         struct list_head        list;
 256         char                    *name;
 257         int                     (*func)(struct ftrace_hash *hash,
 258                                         char *func, char *cmd,
 259                                         char *params, int enable);
 260 };
 261
 262 #ifdef CONFIG_DYNAMIC_FTRACE
 263
 264 int ftrace_arch_code_modify_prepare(void);
 265 int ftrace_arch_code_modify_post_process(void);
 266
 267 struct dyn_ftrace;
 268
 269 void ftrace_bug(int err, struct dyn_ftrace *rec);
 270
 271 struct seq_file;
 272
 273 struct ftrace_probe_ops {
 274         void                    (*func)(unsigned long ip,
 275                                         unsigned long parent_ip,
 276                                         void **data);
 277         int                     (*init)(struct ftrace_probe_ops *ops,
 278                                         unsigned long ip, void **data);
 279         void                    (*free)(struct ftrace_probe_ops *ops,
 280                                         unsigned long ip, void **data);
 281         int                     (*print)(struct seq_file *m,
 282                                          unsigned long ip,
 283                                          struct ftrace_probe_ops *ops,
 284                                          void *data);
 285 };
 286
 287 extern int
 288 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 289                               void *data);
 290 extern void
 291 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 292                                 void *data);
 293 extern void
 294 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 295 extern void unregister_ftrace_function_probe_all(char *glob);
 296
 297 extern int ftrace_text_reserved(const void *start, const void *end);
 298
 299 extern int ftrace_nr_registered_ops(void);
 300
 301 bool is_ftrace_trampoline(unsigned long addr);
 302
 303 /*
 304  * The dyn_ftrace record's flags field is split into two parts.
 305  * the first part which is '0-FTRACE_REF_MAX' is a counter of
 306  * the number of callbacks that have registered the function that
 307  * the dyn_ftrace descriptor represents.
 308  *
 309  * The second part is a mask:
 310  *  ENABLED - the function is being traced
 311  *  REGS    - the record wants the function to save regs
 312  *  REGS_EN - the function is set up to save regs.
 313  *
 314  * When a new ftrace_ops is registered and wants a function to save
 315  * pt_regs, the rec->flag REGS is set. When the function has been
 316  * set up to save regs, the REG_EN flag is set. Once a function
 317  * starts saving regs it will do so until all ftrace_ops are removed
 318  * from tracing that function.
 319  */
 320 enum {
 321         FTRACE_FL_ENABLED       = (1UL << 31),
 322         FTRACE_FL_REGS          = (1UL << 30),
 323         FTRACE_FL_REGS_EN       = (1UL << 29),
 324         FTRACE_FL_TRAMP         = (1UL << 28),
 325         FTRACE_FL_TRAMP_EN      = (1UL << 27),
 326 };
 327
 328 #define FTRACE_REF_MAX_SHIFT    27
 329 #define FTRACE_FL_BITS          5
 330 #define FTRACE_FL_MASKED_BITS   ((1UL << FTRACE_FL_BITS) - 1)
 331 #define FTRACE_FL_MASK          (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
 332 #define FTRACE_REF_MAX          ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
 333
 334 #define ftrace_rec_count(rec)   ((rec)->flags & ~FTRACE_FL_MASK)
 335
 336 struct dyn_ftrace {
 337         unsigned long           ip; /* address of mcount call-site */
 338         unsigned long           flags;
 339         struct dyn_arch_ftrace  arch;
 340 };
 341
 342 int ftrace_force_update(void);
 343 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 344                          int remove, int reset);
 345 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 346                        int len, int reset);
 347 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 348                         int len, int reset);
 349 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 350 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 351 void ftrace_free_filter(struct ftrace_ops *ops);
 352
 353 int register_ftrace_command(struct ftrace_func_command *cmd);
 354 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 355
 356 enum {
 357         FTRACE_UPDATE_CALLS             = (1 << 0),
 358         FTRACE_DISABLE_CALLS            = (1 << 1),
 359         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
 360         FTRACE_START_FUNC_RET           = (1 << 3),
 361         FTRACE_STOP_FUNC_RET            = (1 << 4),
 362 };
 363
 364 /*
 365  * The FTRACE_UPDATE_* enum is used to pass information back
 366  * from the ftrace_update_record() and ftrace_test_record()
 367  * functions. These are called by the code update routines
 368  * to find out what is to be done for a given function.
 369  *
 370  *  IGNORE           - The function is already what we want it to be
 371  *  MAKE_CALL        - Start tracing the function
 372  *  MODIFY_CALL      - Stop saving regs for the function
 373  *  MAKE_NOP         - Stop tracing the function
 374  */
 375 enum {
 376         FTRACE_UPDATE_IGNORE,
 377         FTRACE_UPDATE_MAKE_CALL,
 378         FTRACE_UPDATE_MODIFY_CALL,
 379         FTRACE_UPDATE_MAKE_NOP,
 380 };
 381
 382 enum {
 383         FTRACE_ITER_FILTER      = (1 << 0),
 384         FTRACE_ITER_NOTRACE     = (1 << 1),
 385         FTRACE_ITER_PRINTALL    = (1 << 2),
 386         FTRACE_ITER_DO_HASH     = (1 << 3),
 387         FTRACE_ITER_HASH        = (1 << 4),
 388         FTRACE_ITER_ENABLED     = (1 << 5),
 389 };
 390
 391 void arch_ftrace_update_code(int command);
 392
 393 struct ftrace_rec_iter;
 394
 395 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
 396 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
 397 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
 398
 399 #define for_ftrace_rec_iter(iter)               \
 400         for (iter = ftrace_rec_iter_start();    \
 401              iter;                              \
 402              iter = ftrace_rec_iter_next(iter))
 403
 404
 405 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
 406 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
 407 void ftrace_run_stop_machine(int command);
 408 unsigned long ftrace_location(unsigned long ip);
 409 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
 410 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
 411
 412 extern ftrace_func_t ftrace_trace_function;
 413
 414 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
 415                   struct inode *inode, struct file *file);
 416 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 417                             size_t cnt, loff_t *ppos);
 418 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 419                              size_t cnt, loff_t *ppos);
 420 int ftrace_regex_release(struct inode *inode, struct file *file);
 421
 422 void __init
 423 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
 424
 425 /* defined in arch */
 426 extern int ftrace_ip_converted(unsigned long ip);
 427 extern int ftrace_dyn_arch_init(void);
 428 extern void ftrace_replace_code(int enable);
 429 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 430 extern void ftrace_caller(void);
 431 extern void ftrace_regs_caller(void);
 432 extern void ftrace_call(void);
 433 extern void ftrace_regs_call(void);
 434 extern void mcount_call(void);
 435
 436 void ftrace_modify_all_code(int command);
 437
 438 #ifndef FTRACE_ADDR
 439 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 440 #endif
 441
 442 #ifndef FTRACE_GRAPH_ADDR
 443 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
 444 #endif
 445
 446 #ifndef FTRACE_REGS_ADDR
 447 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 448 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
 449 #else
 450 # define FTRACE_REGS_ADDR FTRACE_ADDR
 451 #endif
 452 #endif
 453
 454 /*
 455  * If an arch would like functions that are only traced
 456  * by the function graph tracer to jump directly to its own
 457  * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
 458  * to be that address to jump to.
 459  */
 460 #ifndef FTRACE_GRAPH_TRAMP_ADDR
 461 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
 462 #endif
 463
 464 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 465 extern void ftrace_graph_caller(void);
 466 extern int ftrace_enable_ftrace_graph_caller(void);
 467 extern int ftrace_disable_ftrace_graph_caller(void);
 468 #else
 469 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 470 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 471 #endif
 472
 473 /**
 474  * ftrace_make_nop - convert code into nop
 475  * @mod: module structure if called by module load initialization
 476  * @rec: the mcount call site record
 477  * @addr: the address that the call site should be calling
 478  *
 479  * This is a very sensitive operation and great care needs
 480  * to be taken by the arch.  The operation should carefully
 481  * read the location, check to see if what is read is indeed
 482  * what we expect it to be, and then on success of the compare,
 483  * it should write to the location.
 484  *
 485  * The code segment at @rec->ip should be a caller to @addr
 486  *
 487  * Return must be:
 488  *  0 on success
 489  *  -EFAULT on error reading the location
 490  *  -EINVAL on a failed compare of the contents
 491  *  -EPERM  on error writing to the location
 492  * Any other value will be considered a failure.
 493  */
 494 extern int ftrace_make_nop(struct module *mod,
 495                            struct dyn_ftrace *rec, unsigned long addr);
 496
 497 /**
 498  * ftrace_make_call - convert a nop call site into a call to addr
 499  * @rec: the mcount call site record
 500  * @addr: the address that the call site should call
 501  *
 502  * This is a very sensitive operation and great care needs
 503  * to be taken by the arch.  The operation should carefully
 504  * read the location, check to see if what is read is indeed
 505  * what we expect it to be, and then on success of the compare,
 506  * it should write to the location.
 507  *
 508  * The code segment at @rec->ip should be a nop
 509  *
 510  * Return must be:
 511  *  0 on success
 512  *  -EFAULT on error reading the location
 513  *  -EINVAL on a failed compare of the contents
 514  *  -EPERM  on error writing to the location
 515  * Any other value will be considered a failure.
 516  */
 517 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 518
 519 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 520 /**
 521  * ftrace_modify_call - convert from one addr to another (no nop)
 522  * @rec: the mcount call site record
 523  * @old_addr: the address expected to be currently called to
 524  * @addr: the address to change to
 525  *
 526  * This is a very sensitive operation and great care needs
 527  * to be taken by the arch.  The operation should carefully
 528  * read the location, check to see if what is read is indeed
 529  * what we expect it to be, and then on success of the compare,
 530  * it should write to the location.
 531  *
 532  * The code segment at @rec->ip should be a caller to @old_addr
 533  *
 534  * Return must be:
 535  *  0 on success
 536  *  -EFAULT on error reading the location
 537  *  -EINVAL on a failed compare of the contents
 538  *  -EPERM  on error writing to the location
 539  * Any other value will be considered a failure.
 540  */
 541 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 542                               unsigned long addr);
 543 #else
 544 /* Should never be called */
 545 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 546                                      unsigned long addr)
 547 {
 548         return -EINVAL;
 549 }
 550 #endif
 551
 552 /* May be defined in arch */
 553 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 554
 555 extern int skip_trace(unsigned long ip);
 556 extern void ftrace_module_init(struct module *mod);
 557
 558 extern void ftrace_disable_daemon(void);
 559 extern void ftrace_enable_daemon(void);
 560 #else /* CONFIG_DYNAMIC_FTRACE */
 561 static inline int skip_trace(unsigned long ip) { return 0; }
 562 static inline int ftrace_force_update(void) { return 0; }
 563 static inline void ftrace_disable_daemon(void) { }
 564 static inline void ftrace_enable_daemon(void) { }
 565 static inline void ftrace_release_mod(struct module *mod) {}
 566 static inline void ftrace_module_init(struct module *mod) {}
 567 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
 568 {
 569         return -EINVAL;
 570 }
 571 static inline __init int unregister_ftrace_command(char *cmd_name)
 572 {
 573         return -EINVAL;
 574 }
 575 static inline int ftrace_text_reserved(const void *start, const void *end)
 576 {
 577         return 0;
 578 }
 579 static inline unsigned long ftrace_location(unsigned long ip)
 580 {
 581         return 0;
 582 }
 583
 584 /*
 585  * Again users of functions that have ftrace_ops may not
 586  * have them defined when ftrace is not enabled, but these
 587  * functions may still be called. Use a macro instead of inline.
 588  */
 589 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
 590 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
 591 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
 592 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
 593 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
 594 #define ftrace_free_filter(ops) do { } while (0)
 595
 596 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 597                             size_t cnt, loff_t *ppos) { return -ENODEV; }
 598 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 599                              size_t cnt, loff_t *ppos) { return -ENODEV; }
 600 static inline int
 601 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
 602
 603 static inline bool is_ftrace_trampoline(unsigned long addr)
 604 {
 605         return false;
 606 }
 607 #endif /* CONFIG_DYNAMIC_FTRACE */
 608
 609 /* totally disable ftrace - can not re-enable after this */
 610 void ftrace_kill(void);
 611
 612 static inline void tracer_disable(void)
 613 {
 614 #ifdef CONFIG_FUNCTION_TRACER
 615         ftrace_enabled = 0;
 616 #endif
 617 }
 618
 619 /*
 620  * Ftrace disable/restore without lock. Some synchronization mechanism
 621  * must be used to prevent ftrace_enabled to be changed between
 622  * disable/restore.
 623  */
 624 static inline int __ftrace_enabled_save(void)
 625 {
 626 #ifdef CONFIG_FUNCTION_TRACER
 627         int saved_ftrace_enabled = ftrace_enabled;
 628         ftrace_enabled = 0;
 629         return saved_ftrace_enabled;
 630 #else
 631         return 0;
 632 #endif
 633 }
 634
 635 static inline void __ftrace_enabled_restore(int enabled)
 636 {
 637 #ifdef CONFIG_FUNCTION_TRACER
 638         ftrace_enabled = enabled;
 639 #endif
 640 }
 641
 642 /* All archs should have this, but we define it for consistency */
 643 #ifndef ftrace_return_address0
 644 # define ftrace_return_address0 __builtin_return_address(0)
 645 #endif
 646
 647 /* Archs may use other ways for ADDR1 and beyond */
 648 #ifndef ftrace_return_address
 649 # ifdef CONFIG_FRAME_POINTER
 650 #  define ftrace_return_address(n) __builtin_return_address(n)
 651 # else
 652 #  define ftrace_return_address(n) 0UL
 653 # endif
 654 #endif
 655
 656 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
 657 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
 658 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
 659 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
 660 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
 661 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
 662 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
 663
 664 #ifdef CONFIG_IRQSOFF_TRACER
 665   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 666   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 667 #else
 668   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
 669   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
 670 #endif
 671
 672 #ifdef CONFIG_PREEMPT_TRACER
 673   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 674   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 675 #else
 676 /*
 677  * Use defines instead of static inlines because some arches will make code out
 678  * of the CALLER_ADDR, when we really want these to be a real nop.
 679  */
 680 # define trace_preempt_on(a0, a1) do { } while (0)
 681 # define trace_preempt_off(a0, a1) do { } while (0)
 682 #endif
 683
 684 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 685 extern void ftrace_init(void);
 686 #else
 687 static inline void ftrace_init(void) { }
 688 #endif
 689
 690 /*
 691  * Structure that defines an entry function trace.
 692  */
 693 struct ftrace_graph_ent {
 694         unsigned long func; /* Current function */
 695         int depth;
 696 };
 697
 698 /*
 699  * Structure that defines a return function trace.
 700  */
 701 struct ftrace_graph_ret {
 702         unsigned long func; /* Current function */
 703         unsigned long long calltime;
 704         unsigned long long rettime;
 705         /* Number of functions that overran the depth limit for current task */
 706         unsigned long overrun;
 707         int depth;
 708 };
 709
 710 /* Type of the callback handlers for tracing function graph*/
 711 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 712 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 713
 714 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 715
 716 /* for init task */
 717 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
 718
 719 /*
 720  * Stack of return addresses for functions
 721  * of a thread.
 722  * Used in struct thread_info
 723  */
 724 struct ftrace_ret_stack {
 725         unsigned long ret;
 726         unsigned long func;
 727         unsigned long long calltime;
 728         unsigned long long subtime;
 729         unsigned long fp;
 730 };
 731
 732 /*
 733  * Primary handler of a function return.
 734  * It relays on ftrace_return_to_handler.
 735  * Defined in entry_32/64.S
 736  */
 737 extern void return_to_handler(void);
 738
 739 extern int
 740 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 741                          unsigned long frame_pointer);
 742
 743 /*
 744  * Sometimes we don't want to trace a function with the function
 745  * graph tracer but we want them to keep traced by the usual function
 746  * tracer if the function graph tracer is not configured.
 747  */
 748 #define __notrace_funcgraph             notrace
 749
 750 /*
 751  * We want to which function is an entrypoint of a hardirq.
 752  * That will help us to put a signal on output.
 753  */
 754 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 755
 756 /* Limits of hardirq entrypoints */
 757 extern char __irqentry_text_start[];
 758 extern char __irqentry_text_end[];
 759
 760 #define FTRACE_NOTRACE_DEPTH 65536
 761 #define FTRACE_RETFUNC_DEPTH 50
 762 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 763 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 764                                 trace_func_graph_ent_t entryfunc);
 765
 766 extern bool ftrace_graph_is_dead(void);
 767 extern void ftrace_graph_stop(void);
 768
 769 /* The current handlers in use */
 770 extern trace_func_graph_ret_t ftrace_graph_return;
 771 extern trace_func_graph_ent_t ftrace_graph_entry;
 772
 773 extern void unregister_ftrace_graph(void);
 774
 775 extern void ftrace_graph_init_task(struct task_struct *t);
 776 extern void ftrace_graph_exit_task(struct task_struct *t);
 777 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
 778
 779 static inline int task_curr_ret_stack(struct task_struct *t)
 780 {
 781         return t->curr_ret_stack;
 782 }
 783
 784 static inline void pause_graph_tracing(void)
 785 {
 786         atomic_inc(&current->tracing_graph_pause);
 787 }
 788
 789 static inline void unpause_graph_tracing(void)
 790 {
 791         atomic_dec(&current->tracing_graph_pause);
 792 }
 793 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 794
 795 #define __notrace_funcgraph
 796 #define __irq_entry
 797 #define INIT_FTRACE_GRAPH
 798
 799 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 800 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 801 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
 802
 803 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 804                           trace_func_graph_ent_t entryfunc)
 805 {
 806         return -1;
 807 }
 808 static inline void unregister_ftrace_graph(void) { }
 809
 810 static inline int task_curr_ret_stack(struct task_struct *tsk)
 811 {
 812         return -1;
 813 }
 814
 815 static inline void pause_graph_tracing(void) { }
 816 static inline void unpause_graph_tracing(void) { }
 817 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 818
 819 #ifdef CONFIG_TRACING
 820
 821 /* flags for current->trace */
 822 enum {
 823         TSK_TRACE_FL_TRACE_BIT  = 0,
 824         TSK_TRACE_FL_GRAPH_BIT  = 1,
 825 };
 826 enum {
 827         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 828         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 829 };
 830
 831 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 832 {
 833         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 834 }
 835
 836 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 837 {
 838         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 839 }
 840
 841 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 842 {
 843         return tsk->trace & TSK_TRACE_FL_TRACE;
 844 }
 845
 846 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 847 {
 848         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 849 }
 850
 851 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 852 {
 853         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 854 }
 855
 856 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 857 {
 858         return tsk->trace & TSK_TRACE_FL_GRAPH;
 859 }
 860
 861 enum ftrace_dump_mode;
 862
 863 extern enum ftrace_dump_mode ftrace_dump_on_oops;
 864
 865 extern void disable_trace_on_warning(void);
 866 extern int __disable_trace_on_warning;
 867
 868 #ifdef CONFIG_PREEMPT
 869 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
 870 #endif
 871
 872 #else /* CONFIG_TRACING */
 873 static inline void  disable_trace_on_warning(void) { }
 874 #endif /* CONFIG_TRACING */
 875
 876 #ifndef INIT_TRACE_RECURSION
 877 #define INIT_TRACE_RECURSION
 878 #endif
 879
 880 #ifdef CONFIG_FTRACE_SYSCALLS
 881
 882 unsigned long arch_syscall_addr(int nr);
 883
 884 #endif /* CONFIG_FTRACE_SYSCALLS */
 885
 886 #endif /* _LINUX_FTRACE_H */