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 /*
  60  * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
  61  * set in the flags member.
  62  *
  63  * ENABLED - set/unset when ftrace_ops is registered/unregistered
  64  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
  65  *           allocated ftrace_ops which need special care
  66  * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
  67  *           could be controled by following calls:
  68  *             ftrace_function_local_enable
  69  *             ftrace_function_local_disable
  70  * SAVE_REGS - The ftrace_ops wants regs saved at each function called
  71  *            and passed to the callback. If this flag is set, but the
  72  *            architecture does not support passing regs
  73  *            (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
  74  *            ftrace_ops will fail to register, unless the next flag
  75  *            is set.
  76  * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
  77  *            handler can handle an arch that does not save regs
  78  *            (the handler tests if regs == NULL), then it can set
  79  *            this flag instead. It will not fail registering the ftrace_ops
  80  *            but, the regs field will be NULL if the arch does not support
  81  *            passing regs to the handler.
  82  *            Note, if this flag is set, the SAVE_REGS flag will automatically
  83  *            get set upon registering the ftrace_ops, if the arch supports it.
  84  * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
  85  *            that the call back has its own recursion protection. If it does
  86  *            not set this, then the ftrace infrastructure will add recursion
  87  *            protection for the caller.
  88  * STUB   - The ftrace_ops is just a place holder.
  89  * INITIALIZED - The ftrace_ops has already been initialized (first use time
  90  *            register_ftrace_function() is called, it will initialized the ops)
  91  * DELETED - The ops are being deleted, do not let them be registered again.
  92  */
  93 enum {
  94         FTRACE_OPS_FL_ENABLED                   = 1 << 0,
  95         FTRACE_OPS_FL_DYNAMIC                   = 1 << 1,
  96         FTRACE_OPS_FL_CONTROL                   = 1 << 2,
  97         FTRACE_OPS_FL_SAVE_REGS                 = 1 << 3,
  98         FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED    = 1 << 4,
  99         FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 5,
 100         FTRACE_OPS_FL_STUB                      = 1 << 6,
 101         FTRACE_OPS_FL_INITIALIZED               = 1 << 7,
 102         FTRACE_OPS_FL_DELETED                   = 1 << 8,
 103 };
 104
 105 /*
 106  * Note, ftrace_ops can be referenced outside of RCU protection.
 107  * (Although, for perf, the control ops prevent that). If ftrace_ops is
 108  * allocated and not part of kernel core data, the unregistering of it will
 109  * perform a scheduling on all CPUs to make sure that there are no more users.
 110  * Depending on the load of the system that may take a bit of time.
 111  *
 112  * Any private data added must also take care not to be freed and if private
 113  * data is added to a ftrace_ops that is in core code, the user of the
 114  * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
 115  */
 116 struct ftrace_ops {
 117         ftrace_func_t                   func;
 118         struct ftrace_ops               *next;
 119         unsigned long                   flags;
 120         void                            *private;
 121         int __percpu                    *disabled;
 122 #ifdef CONFIG_DYNAMIC_FTRACE
 123         int                             nr_trampolines;
 124         struct ftrace_hash              *notrace_hash;
 125         struct ftrace_hash              *filter_hash;
 126         struct ftrace_hash              *tramp_hash;
 127         struct mutex                    regex_lock;
 128         unsigned long                   trampoline;
 129 #endif
 130 };
 131
 132 /*
 133  * Type of the current tracing.
 134  */
 135 enum ftrace_tracing_type_t {
 136         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
 137         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
 138 };
 139
 140 /* Current tracing type, default is FTRACE_TYPE_ENTER */
 141 extern enum ftrace_tracing_type_t ftrace_tracing_type;
 142
 143 /*
 144  * The ftrace_ops must be a static and should also
 145  * be read_mostly.  These functions do modify read_mostly variables
 146  * so use them sparely. Never free an ftrace_op or modify the
 147  * next pointer after it has been registered. Even after unregistering
 148  * it, the next pointer may still be used internally.
 149  */
 150 int register_ftrace_function(struct ftrace_ops *ops);
 151 int unregister_ftrace_function(struct ftrace_ops *ops);
 152 void clear_ftrace_function(void);
 153
 154 /**
 155  * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
 156  *
 157  * This function enables tracing on current cpu by decreasing
 158  * the per cpu control variable.
 159  * It must be called with preemption disabled and only on ftrace_ops
 160  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 161  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 162  */
 163 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
 164 {
 165         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 166                 return;
 167
 168         (*this_cpu_ptr(ops->disabled))--;
 169 }
 170
 171 /**
 172  * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
 173  *
 174  * This function enables tracing on current cpu by decreasing
 175  * the per cpu control variable.
 176  * It must be called with preemption disabled and only on ftrace_ops
 177  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 178  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 179  */
 180 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
 181 {
 182         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 183                 return;
 184
 185         (*this_cpu_ptr(ops->disabled))++;
 186 }
 187
 188 /**
 189  * ftrace_function_local_disabled - returns ftrace_ops disabled value
 190  *                                  on current cpu
 191  *
 192  * This function returns value of ftrace_ops::disabled on current cpu.
 193  * It must be called with preemption disabled and only on ftrace_ops
 194  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 195  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 196  */
 197 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
 198 {
 199         WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
 200         return *this_cpu_ptr(ops->disabled);
 201 }
 202
 203 extern void ftrace_stub(unsigned long a0, unsigned long a1,
 204                         struct ftrace_ops *op, struct pt_regs *regs);
 205
 206 #else /* !CONFIG_FUNCTION_TRACER */
 207 /*
 208  * (un)register_ftrace_function must be a macro since the ops parameter
 209  * must not be evaluated.
 210  */
 211 #define register_ftrace_function(ops) ({ 0; })
 212 #define unregister_ftrace_function(ops) ({ 0; })
 213 static inline int ftrace_nr_registered_ops(void)
 214 {
 215         return 0;
 216 }
 217 static inline void clear_ftrace_function(void) { }
 218 static inline void ftrace_kill(void) { }
 219 #endif /* CONFIG_FUNCTION_TRACER */
 220
 221 #ifdef CONFIG_STACK_TRACER
 222 extern int stack_tracer_enabled;
 223 int
 224 stack_trace_sysctl(struct ctl_table *table, int write,
 225                    void __user *buffer, size_t *lenp,
 226                    loff_t *ppos);
 227 #endif
 228
 229 struct ftrace_func_command {
 230         struct list_head        list;
 231         char                    *name;
 232         int                     (*func)(struct ftrace_hash *hash,
 233                                         char *func, char *cmd,
 234                                         char *params, int enable);
 235 };
 236
 237 #ifdef CONFIG_DYNAMIC_FTRACE
 238
 239 int ftrace_arch_code_modify_prepare(void);
 240 int ftrace_arch_code_modify_post_process(void);
 241
 242 void ftrace_bug(int err, unsigned long ip);
 243
 244 struct seq_file;
 245
 246 struct ftrace_probe_ops {
 247         void                    (*func)(unsigned long ip,
 248                                         unsigned long parent_ip,
 249                                         void **data);
 250         int                     (*init)(struct ftrace_probe_ops *ops,
 251                                         unsigned long ip, void **data);
 252         void                    (*free)(struct ftrace_probe_ops *ops,
 253                                         unsigned long ip, void **data);
 254         int                     (*print)(struct seq_file *m,
 255                                          unsigned long ip,
 256                                          struct ftrace_probe_ops *ops,
 257                                          void *data);
 258 };
 259
 260 extern int
 261 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 262                               void *data);
 263 extern void
 264 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 265                                 void *data);
 266 extern void
 267 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 268 extern void unregister_ftrace_function_probe_all(char *glob);
 269
 270 extern int ftrace_text_reserved(const void *start, const void *end);
 271
 272 extern int ftrace_nr_registered_ops(void);
 273
 274 /*
 275  * The dyn_ftrace record's flags field is split into two parts.
 276  * the first part which is '0-FTRACE_REF_MAX' is a counter of
 277  * the number of callbacks that have registered the function that
 278  * the dyn_ftrace descriptor represents.
 279  *
 280  * The second part is a mask:
 281  *  ENABLED - the function is being traced
 282  *  REGS    - the record wants the function to save regs
 283  *  REGS_EN - the function is set up to save regs.
 284  *
 285  * When a new ftrace_ops is registered and wants a function to save
 286  * pt_regs, the rec->flag REGS is set. When the function has been
 287  * set up to save regs, the REG_EN flag is set. Once a function
 288  * starts saving regs it will do so until all ftrace_ops are removed
 289  * from tracing that function.
 290  */
 291 enum {
 292         FTRACE_FL_ENABLED       = (1UL << 31),
 293         FTRACE_FL_REGS          = (1UL << 30),
 294         FTRACE_FL_REGS_EN       = (1UL << 29),
 295         FTRACE_FL_TRAMP         = (1UL << 28),
 296         FTRACE_FL_TRAMP_EN      = (1UL << 27),
 297 };
 298
 299 #define FTRACE_REF_MAX_SHIFT    27
 300 #define FTRACE_FL_BITS          5
 301 #define FTRACE_FL_MASKED_BITS   ((1UL << FTRACE_FL_BITS) - 1)
 302 #define FTRACE_FL_MASK          (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
 303 #define FTRACE_REF_MAX          ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
 304
 305 #define ftrace_rec_count(rec)   ((rec)->flags & ~FTRACE_FL_MASK)
 306
 307 struct dyn_ftrace {
 308         unsigned long           ip; /* address of mcount call-site */
 309         unsigned long           flags;
 310         struct dyn_arch_ftrace  arch;
 311 };
 312
 313 int ftrace_force_update(void);
 314 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 315                          int remove, int reset);
 316 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 317                        int len, int reset);
 318 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 319                         int len, int reset);
 320 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 321 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 322 void ftrace_free_filter(struct ftrace_ops *ops);
 323
 324 int register_ftrace_command(struct ftrace_func_command *cmd);
 325 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 326
 327 enum {
 328         FTRACE_UPDATE_CALLS             = (1 << 0),
 329         FTRACE_DISABLE_CALLS            = (1 << 1),
 330         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
 331         FTRACE_START_FUNC_RET           = (1 << 3),
 332         FTRACE_STOP_FUNC_RET            = (1 << 4),
 333 };
 334
 335 /*
 336  * The FTRACE_UPDATE_* enum is used to pass information back
 337  * from the ftrace_update_record() and ftrace_test_record()
 338  * functions. These are called by the code update routines
 339  * to find out what is to be done for a given function.
 340  *
 341  *  IGNORE           - The function is already what we want it to be
 342  *  MAKE_CALL        - Start tracing the function
 343  *  MODIFY_CALL      - Stop saving regs for the function
 344  *  MAKE_NOP         - Stop tracing the function
 345  */
 346 enum {
 347         FTRACE_UPDATE_IGNORE,
 348         FTRACE_UPDATE_MAKE_CALL,
 349         FTRACE_UPDATE_MODIFY_CALL,
 350         FTRACE_UPDATE_MAKE_NOP,
 351 };
 352
 353 enum {
 354         FTRACE_ITER_FILTER      = (1 << 0),
 355         FTRACE_ITER_NOTRACE     = (1 << 1),
 356         FTRACE_ITER_PRINTALL    = (1 << 2),
 357         FTRACE_ITER_DO_HASH     = (1 << 3),
 358         FTRACE_ITER_HASH        = (1 << 4),
 359         FTRACE_ITER_ENABLED     = (1 << 5),
 360 };
 361
 362 void arch_ftrace_update_code(int command);
 363
 364 struct ftrace_rec_iter;
 365
 366 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
 367 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
 368 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
 369
 370 #define for_ftrace_rec_iter(iter)               \
 371         for (iter = ftrace_rec_iter_start();    \
 372              iter;                              \
 373              iter = ftrace_rec_iter_next(iter))
 374
 375
 376 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
 377 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
 378 void ftrace_run_stop_machine(int command);
 379 unsigned long ftrace_location(unsigned long ip);
 380 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
 381 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
 382
 383 extern ftrace_func_t ftrace_trace_function;
 384
 385 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
 386                   struct inode *inode, struct file *file);
 387 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 388                             size_t cnt, loff_t *ppos);
 389 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 390                              size_t cnt, loff_t *ppos);
 391 int ftrace_regex_release(struct inode *inode, struct file *file);
 392
 393 void __init
 394 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
 395
 396 /* defined in arch */
 397 extern int ftrace_ip_converted(unsigned long ip);
 398 extern int ftrace_dyn_arch_init(void);
 399 extern void ftrace_replace_code(int enable);
 400 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 401 extern void ftrace_caller(void);
 402 extern void ftrace_regs_caller(void);
 403 extern void ftrace_call(void);
 404 extern void ftrace_regs_call(void);
 405 extern void mcount_call(void);
 406
 407 void ftrace_modify_all_code(int command);
 408
 409 #ifndef FTRACE_ADDR
 410 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 411 #endif
 412
 413 #ifndef FTRACE_GRAPH_ADDR
 414 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
 415 #endif
 416
 417 #ifndef FTRACE_REGS_ADDR
 418 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 419 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
 420 #else
 421 # define FTRACE_REGS_ADDR FTRACE_ADDR
 422 #endif
 423 #endif
 424
 425 /*
 426  * If an arch would like functions that are only traced
 427  * by the function graph tracer to jump directly to its own
 428  * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
 429  * to be that address to jump to.
 430  */
 431 #ifndef FTRACE_GRAPH_TRAMP_ADDR
 432 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
 433 #endif
 434
 435 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 436 extern void ftrace_graph_caller(void);
 437 extern int ftrace_enable_ftrace_graph_caller(void);
 438 extern int ftrace_disable_ftrace_graph_caller(void);
 439 #else
 440 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 441 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 442 #endif
 443
 444 /**
 445  * ftrace_make_nop - convert code into nop
 446  * @mod: module structure if called by module load initialization
 447  * @rec: the mcount call site record
 448  * @addr: the address that the call site should be calling
 449  *
 450  * This is a very sensitive operation and great care needs
 451  * to be taken by the arch.  The operation should carefully
 452  * read the location, check to see if what is read is indeed
 453  * what we expect it to be, and then on success of the compare,
 454  * it should write to the location.
 455  *
 456  * The code segment at @rec->ip should be a caller to @addr
 457  *
 458  * Return must be:
 459  *  0 on success
 460  *  -EFAULT on error reading the location
 461  *  -EINVAL on a failed compare of the contents
 462  *  -EPERM  on error writing to the location
 463  * Any other value will be considered a failure.
 464  */
 465 extern int ftrace_make_nop(struct module *mod,
 466                            struct dyn_ftrace *rec, unsigned long addr);
 467
 468 /**
 469  * ftrace_make_call - convert a nop call site into a call to addr
 470  * @rec: the mcount call site record
 471  * @addr: the address that the call site should call
 472  *
 473  * This is a very sensitive operation and great care needs
 474  * to be taken by the arch.  The operation should carefully
 475  * read the location, check to see if what is read is indeed
 476  * what we expect it to be, and then on success of the compare,
 477  * it should write to the location.
 478  *
 479  * The code segment at @rec->ip should be a nop
 480  *
 481  * Return must be:
 482  *  0 on success
 483  *  -EFAULT on error reading the location
 484  *  -EINVAL on a failed compare of the contents
 485  *  -EPERM  on error writing to the location
 486  * Any other value will be considered a failure.
 487  */
 488 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 489
 490 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 491 /**
 492  * ftrace_modify_call - convert from one addr to another (no nop)
 493  * @rec: the mcount call site record
 494  * @old_addr: the address expected to be currently called to
 495  * @addr: the address to change to
 496  *
 497  * This is a very sensitive operation and great care needs
 498  * to be taken by the arch.  The operation should carefully
 499  * read the location, check to see if what is read is indeed
 500  * what we expect it to be, and then on success of the compare,
 501  * it should write to the location.
 502  *
 503  * The code segment at @rec->ip should be a caller to @old_addr
 504  *
 505  * Return must be:
 506  *  0 on success
 507  *  -EFAULT on error reading the location
 508  *  -EINVAL on a failed compare of the contents
 509  *  -EPERM  on error writing to the location
 510  * Any other value will be considered a failure.
 511  */
 512 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 513                               unsigned long addr);
 514 #else
 515 /* Should never be called */
 516 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 517                                      unsigned long addr)
 518 {
 519         return -EINVAL;
 520 }
 521 #endif
 522
 523 /* May be defined in arch */
 524 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 525
 526 extern int skip_trace(unsigned long ip);
 527 extern void ftrace_module_init(struct module *mod);
 528
 529 extern void ftrace_disable_daemon(void);
 530 extern void ftrace_enable_daemon(void);
 531 #else /* CONFIG_DYNAMIC_FTRACE */
 532 static inline int skip_trace(unsigned long ip) { return 0; }
 533 static inline int ftrace_force_update(void) { return 0; }
 534 static inline void ftrace_disable_daemon(void) { }
 535 static inline void ftrace_enable_daemon(void) { }
 536 static inline void ftrace_release_mod(struct module *mod) {}
 537 static inline void ftrace_module_init(struct module *mod) {}
 538 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
 539 {
 540         return -EINVAL;
 541 }
 542 static inline __init int unregister_ftrace_command(char *cmd_name)
 543 {
 544         return -EINVAL;
 545 }
 546 static inline int ftrace_text_reserved(const void *start, const void *end)
 547 {
 548         return 0;
 549 }
 550 static inline unsigned long ftrace_location(unsigned long ip)
 551 {
 552         return 0;
 553 }
 554
 555 /*
 556  * Again users of functions that have ftrace_ops may not
 557  * have them defined when ftrace is not enabled, but these
 558  * functions may still be called. Use a macro instead of inline.
 559  */
 560 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
 561 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
 562 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
 563 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
 564 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
 565 #define ftrace_free_filter(ops) do { } while (0)
 566
 567 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 568                             size_t cnt, loff_t *ppos) { return -ENODEV; }
 569 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 570                              size_t cnt, loff_t *ppos) { return -ENODEV; }
 571 static inline int
 572 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
 573 #endif /* CONFIG_DYNAMIC_FTRACE */
 574
 575 /* totally disable ftrace - can not re-enable after this */
 576 void ftrace_kill(void);
 577
 578 static inline void tracer_disable(void)
 579 {
 580 #ifdef CONFIG_FUNCTION_TRACER
 581         ftrace_enabled = 0;
 582 #endif
 583 }
 584
 585 /*
 586  * Ftrace disable/restore without lock. Some synchronization mechanism
 587  * must be used to prevent ftrace_enabled to be changed between
 588  * disable/restore.
 589  */
 590 static inline int __ftrace_enabled_save(void)
 591 {
 592 #ifdef CONFIG_FUNCTION_TRACER
 593         int saved_ftrace_enabled = ftrace_enabled;
 594         ftrace_enabled = 0;
 595         return saved_ftrace_enabled;
 596 #else
 597         return 0;
 598 #endif
 599 }
 600
 601 static inline void __ftrace_enabled_restore(int enabled)
 602 {
 603 #ifdef CONFIG_FUNCTION_TRACER
 604         ftrace_enabled = enabled;
 605 #endif
 606 }
 607
 608 /* All archs should have this, but we define it for consistency */
 609 #ifndef ftrace_return_address0
 610 # define ftrace_return_address0 __builtin_return_address(0)
 611 #endif
 612
 613 /* Archs may use other ways for ADDR1 and beyond */
 614 #ifndef ftrace_return_address
 615 # ifdef CONFIG_FRAME_POINTER
 616 #  define ftrace_return_address(n) __builtin_return_address(n)
 617 # else
 618 #  define ftrace_return_address(n) 0UL
 619 # endif
 620 #endif
 621
 622 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
 623 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
 624 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
 625 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
 626 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
 627 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
 628 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
 629
 630 #ifdef CONFIG_IRQSOFF_TRACER
 631   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 632   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 633 #else
 634   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
 635   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
 636 #endif
 637
 638 #ifdef CONFIG_PREEMPT_TRACER
 639   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 640   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 641 #else
 642 /*
 643  * Use defines instead of static inlines because some arches will make code out
 644  * of the CALLER_ADDR, when we really want these to be a real nop.
 645  */
 646 # define trace_preempt_on(a0, a1) do { } while (0)
 647 # define trace_preempt_off(a0, a1) do { } while (0)
 648 #endif
 649
 650 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 651 extern void ftrace_init(void);
 652 #else
 653 static inline void ftrace_init(void) { }
 654 #endif
 655
 656 /*
 657  * Structure that defines an entry function trace.
 658  */
 659 struct ftrace_graph_ent {
 660         unsigned long func; /* Current function */
 661         int depth;
 662 };
 663
 664 /*
 665  * Structure that defines a return function trace.
 666  */
 667 struct ftrace_graph_ret {
 668         unsigned long func; /* Current function */
 669         unsigned long long calltime;
 670         unsigned long long rettime;
 671         /* Number of functions that overran the depth limit for current task */
 672         unsigned long overrun;
 673         int depth;
 674 };
 675
 676 /* Type of the callback handlers for tracing function graph*/
 677 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 678 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 679
 680 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 681
 682 /* for init task */
 683 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
 684
 685 /*
 686  * Stack of return addresses for functions
 687  * of a thread.
 688  * Used in struct thread_info
 689  */
 690 struct ftrace_ret_stack {
 691         unsigned long ret;
 692         unsigned long func;
 693         unsigned long long calltime;
 694         unsigned long long subtime;
 695         unsigned long fp;
 696 };
 697
 698 /*
 699  * Primary handler of a function return.
 700  * It relays on ftrace_return_to_handler.
 701  * Defined in entry_32/64.S
 702  */
 703 extern void return_to_handler(void);
 704
 705 extern int
 706 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 707                          unsigned long frame_pointer);
 708
 709 /*
 710  * Sometimes we don't want to trace a function with the function
 711  * graph tracer but we want them to keep traced by the usual function
 712  * tracer if the function graph tracer is not configured.
 713  */
 714 #define __notrace_funcgraph             notrace
 715
 716 /*
 717  * We want to which function is an entrypoint of a hardirq.
 718  * That will help us to put a signal on output.
 719  */
 720 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 721
 722 /* Limits of hardirq entrypoints */
 723 extern char __irqentry_text_start[];
 724 extern char __irqentry_text_end[];
 725
 726 #define FTRACE_NOTRACE_DEPTH 65536
 727 #define FTRACE_RETFUNC_DEPTH 50
 728 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 729 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 730                                 trace_func_graph_ent_t entryfunc);
 731
 732 extern bool ftrace_graph_is_dead(void);
 733 extern void ftrace_graph_stop(void);
 734
 735 /* The current handlers in use */
 736 extern trace_func_graph_ret_t ftrace_graph_return;
 737 extern trace_func_graph_ent_t ftrace_graph_entry;
 738
 739 extern void unregister_ftrace_graph(void);
 740
 741 extern void ftrace_graph_init_task(struct task_struct *t);
 742 extern void ftrace_graph_exit_task(struct task_struct *t);
 743 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
 744
 745 static inline int task_curr_ret_stack(struct task_struct *t)
 746 {
 747         return t->curr_ret_stack;
 748 }
 749
 750 static inline void pause_graph_tracing(void)
 751 {
 752         atomic_inc(&current->tracing_graph_pause);
 753 }
 754
 755 static inline void unpause_graph_tracing(void)
 756 {
 757         atomic_dec(&current->tracing_graph_pause);
 758 }
 759 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 760
 761 #define __notrace_funcgraph
 762 #define __irq_entry
 763 #define INIT_FTRACE_GRAPH
 764
 765 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 766 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 767 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
 768
 769 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 770                           trace_func_graph_ent_t entryfunc)
 771 {
 772         return -1;
 773 }
 774 static inline void unregister_ftrace_graph(void) { }
 775
 776 static inline int task_curr_ret_stack(struct task_struct *tsk)
 777 {
 778         return -1;
 779 }
 780
 781 static inline void pause_graph_tracing(void) { }
 782 static inline void unpause_graph_tracing(void) { }
 783 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 784
 785 #ifdef CONFIG_TRACING
 786
 787 /* flags for current->trace */
 788 enum {
 789         TSK_TRACE_FL_TRACE_BIT  = 0,
 790         TSK_TRACE_FL_GRAPH_BIT  = 1,
 791 };
 792 enum {
 793         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 794         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 795 };
 796
 797 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 798 {
 799         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 800 }
 801
 802 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 803 {
 804         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 805 }
 806
 807 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 808 {
 809         return tsk->trace & TSK_TRACE_FL_TRACE;
 810 }
 811
 812 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 813 {
 814         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 815 }
 816
 817 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 818 {
 819         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 820 }
 821
 822 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 823 {
 824         return tsk->trace & TSK_TRACE_FL_GRAPH;
 825 }
 826
 827 enum ftrace_dump_mode;
 828
 829 extern enum ftrace_dump_mode ftrace_dump_on_oops;
 830
 831 extern void disable_trace_on_warning(void);
 832 extern int __disable_trace_on_warning;
 833
 834 #ifdef CONFIG_PREEMPT
 835 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
 836 #endif
 837
 838 #else /* CONFIG_TRACING */
 839 static inline void  disable_trace_on_warning(void) { }
 840 #endif /* CONFIG_TRACING */
 841
 842 #ifndef INIT_TRACE_RECURSION
 843 #define INIT_TRACE_RECURSION
 844 #endif
 845
 846 #ifdef CONFIG_FTRACE_SYSCALLS
 847
 848 unsigned long arch_syscall_addr(int nr);
 849
 850 #endif /* CONFIG_FTRACE_SYSCALLS */
 851
 852 #endif /* _LINUX_FTRACE_H */