include/linux/ftrace.h

   1 /*
   2  * Ftrace header.  For implementation details beyond the random comments
   3  * scattered below, see: Documentation/trace/ftrace-design.txt
   4  */
   5
   6 #ifndef _LINUX_FTRACE_H
   7 #define _LINUX_FTRACE_H
   8
   9 #include <linux/trace_clock.h>
  10 #include <linux/kallsyms.h>
  11 #include <linux/linkage.h>
  12 #include <linux/bitops.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/ktime.h>
  15 #include <linux/sched.h>
  16 #include <linux/types.h>
  17 #include <linux/init.h>
  18 #include <linux/fs.h>
  19
  20 #include <asm/ftrace.h>
  21
  22 /*
  23  * If the arch supports passing the variable contents of
  24  * function_trace_op as the third parameter back from the
  25  * mcount call, then the arch should define this as 1.
  26  */
  27 #ifndef ARCH_SUPPORTS_FTRACE_OPS
  28 #define ARCH_SUPPORTS_FTRACE_OPS 0
  29 #endif
  30
  31 /*
  32  * If the arch's mcount caller does not support all of ftrace's
  33  * features, then it must call an indirect function that
  34  * does. Or at least does enough to prevent any unwelcomed side effects.
  35  */
  36 #if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \
  37         !ARCH_SUPPORTS_FTRACE_OPS
  38 # define FTRACE_FORCE_LIST_FUNC 1
  39 #else
  40 # define FTRACE_FORCE_LIST_FUNC 0
  41 #endif
  42
  43
  44 struct module;
  45 struct ftrace_hash;
  46
  47 #ifdef CONFIG_FUNCTION_TRACER
  48
  49 extern int ftrace_enabled;
  50 extern int
  51 ftrace_enable_sysctl(struct ctl_table *table, int write,
  52                      void __user *buffer, size_t *lenp,
  53                      loff_t *ppos);
  54
  55 struct ftrace_ops;
  56
  57 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
  58                               struct ftrace_ops *op, struct pt_regs *regs);
  59
  60 /*
  61  * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
  62  * set in the flags member.
  63  *
  64  * ENABLED - set/unset when ftrace_ops is registered/unregistered
  65  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
  66  *           allocated ftrace_ops which need special care
  67  * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
  68  *           could be controled by following calls:
  69  *             ftrace_function_local_enable
  70  *             ftrace_function_local_disable
  71  * SAVE_REGS - The ftrace_ops wants regs saved at each function called
  72  *            and passed to the callback. If this flag is set, but the
  73  *            architecture does not support passing regs
  74  *            (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
  75  *            ftrace_ops will fail to register, unless the next flag
  76  *            is set.
  77  * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
  78  *            handler can handle an arch that does not save regs
  79  *            (the handler tests if regs == NULL), then it can set
  80  *            this flag instead. It will not fail registering the ftrace_ops
  81  *            but, the regs field will be NULL if the arch does not support
  82  *            passing regs to the handler.
  83  *            Note, if this flag is set, the SAVE_REGS flag will automatically
  84  *            get set upon registering the ftrace_ops, if the arch supports it.
  85  * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
  86  *            that the call back has its own recursion protection. If it does
  87  *            not set this, then the ftrace infrastructure will add recursion
  88  *            protection for the caller.
  89  * STUB   - The ftrace_ops is just a place holder.
  90  * INITIALIZED - The ftrace_ops has already been initialized (first use time
  91  *            register_ftrace_function() is called, it will initialized the ops)
  92  * DELETED - The ops are being deleted, do not let them be registered again.
  93  */
  94 enum {
  95         FTRACE_OPS_FL_ENABLED                   = 1 << 0,
  96         FTRACE_OPS_FL_DYNAMIC                   = 1 << 1,
  97         FTRACE_OPS_FL_CONTROL                   = 1 << 2,
  98         FTRACE_OPS_FL_SAVE_REGS                 = 1 << 3,
  99         FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED    = 1 << 4,
 100         FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 5,
 101         FTRACE_OPS_FL_STUB                      = 1 << 6,
 102         FTRACE_OPS_FL_INITIALIZED               = 1 << 7,
 103         FTRACE_OPS_FL_DELETED                   = 1 << 8,
 104 };
 105
 106 /*
 107  * Note, ftrace_ops can be referenced outside of RCU protection.
 108  * (Although, for perf, the control ops prevent that). If ftrace_ops is
 109  * allocated and not part of kernel core data, the unregistering of it will
 110  * perform a scheduling on all CPUs to make sure that there are no more users.
 111  * Depending on the load of the system that may take a bit of time.
 112  *
 113  * Any private data added must also take care not to be freed and if private
 114  * data is added to a ftrace_ops that is in core code, the user of the
 115  * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
 116  */
 117 struct ftrace_ops {
 118         ftrace_func_t                   func;
 119         struct ftrace_ops               *next;
 120         unsigned long                   flags;
 121         void                            *private;
 122         int __percpu                    *disabled;
 123 #ifdef CONFIG_DYNAMIC_FTRACE
 124         int                             trampolines;
 125         struct ftrace_hash              *notrace_hash;
 126         struct ftrace_hash              *filter_hash;
 127         struct ftrace_hash              *tramp_hash;
 128         struct mutex                    regex_lock;
 129         unsigned long                   trampoline;
 130 #endif
 131 };
 132
 133 extern int function_trace_stop;
 134
 135 /*
 136  * Type of the current tracing.
 137  */
 138 enum ftrace_tracing_type_t {
 139         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
 140         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
 141 };
 142
 143 /* Current tracing type, default is FTRACE_TYPE_ENTER */
 144 extern enum ftrace_tracing_type_t ftrace_tracing_type;
 145
 146 /*
 147  * The ftrace_ops must be a static and should also
 148  * be read_mostly.  These functions do modify read_mostly variables
 149  * so use them sparely. Never free an ftrace_op or modify the
 150  * next pointer after it has been registered. Even after unregistering
 151  * it, the next pointer may still be used internally.
 152  */
 153 int register_ftrace_function(struct ftrace_ops *ops);
 154 int unregister_ftrace_function(struct ftrace_ops *ops);
 155 void clear_ftrace_function(void);
 156
 157 /**
 158  * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
 159  *
 160  * This function enables tracing on current cpu by decreasing
 161  * the per cpu control variable.
 162  * It must be called with preemption disabled and only on ftrace_ops
 163  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 164  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 165  */
 166 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
 167 {
 168         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 169                 return;
 170
 171         (*this_cpu_ptr(ops->disabled))--;
 172 }
 173
 174 /**
 175  * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
 176  *
 177  * This function enables tracing on current cpu by decreasing
 178  * the per cpu control variable.
 179  * It must be called with preemption disabled and only on ftrace_ops
 180  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 181  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 182  */
 183 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
 184 {
 185         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 186                 return;
 187
 188         (*this_cpu_ptr(ops->disabled))++;
 189 }
 190
 191 /**
 192  * ftrace_function_local_disabled - returns ftrace_ops disabled value
 193  *                                  on current cpu
 194  *
 195  * This function returns value of ftrace_ops::disabled on current cpu.
 196  * It must be called with preemption disabled and only on ftrace_ops
 197  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 198  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 199  */
 200 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
 201 {
 202         WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
 203         return *this_cpu_ptr(ops->disabled);
 204 }
 205
 206 extern void ftrace_stub(unsigned long a0, unsigned long a1,
 207                         struct ftrace_ops *op, struct pt_regs *regs);
 208
 209 #else /* !CONFIG_FUNCTION_TRACER */
 210 /*
 211  * (un)register_ftrace_function must be a macro since the ops parameter
 212  * must not be evaluated.
 213  */
 214 #define register_ftrace_function(ops) ({ 0; })
 215 #define unregister_ftrace_function(ops) ({ 0; })
 216 static inline int ftrace_nr_registered_ops(void)
 217 {
 218         return 0;
 219 }
 220 static inline void clear_ftrace_function(void) { }
 221 static inline void ftrace_kill(void) { }
 222 #endif /* CONFIG_FUNCTION_TRACER */
 223
 224 #ifdef CONFIG_STACK_TRACER
 225 extern int stack_tracer_enabled;
 226 int
 227 stack_trace_sysctl(struct ctl_table *table, int write,
 228                    void __user *buffer, size_t *lenp,
 229                    loff_t *ppos);
 230 #endif
 231
 232 struct ftrace_func_command {
 233         struct list_head        list;
 234         char                    *name;
 235         int                     (*func)(struct ftrace_hash *hash,
 236                                         char *func, char *cmd,
 237                                         char *params, int enable);
 238 };
 239
 240 #ifdef CONFIG_DYNAMIC_FTRACE
 241
 242 int ftrace_arch_code_modify_prepare(void);
 243 int ftrace_arch_code_modify_post_process(void);
 244
 245 void ftrace_bug(int err, unsigned long ip);
 246
 247 struct seq_file;
 248
 249 struct ftrace_probe_ops {
 250         void                    (*func)(unsigned long ip,
 251                                         unsigned long parent_ip,
 252                                         void **data);
 253         int                     (*init)(struct ftrace_probe_ops *ops,
 254                                         unsigned long ip, void **data);
 255         void                    (*free)(struct ftrace_probe_ops *ops,
 256                                         unsigned long ip, void **data);
 257         int                     (*print)(struct seq_file *m,
 258                                          unsigned long ip,
 259                                          struct ftrace_probe_ops *ops,
 260                                          void *data);
 261 };
 262
 263 extern int
 264 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 265                               void *data);
 266 extern void
 267 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 268                                 void *data);
 269 extern void
 270 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 271 extern void unregister_ftrace_function_probe_all(char *glob);
 272
 273 extern int ftrace_text_reserved(const void *start, const void *end);
 274
 275 extern int ftrace_nr_registered_ops(void);
 276
 277 /*
 278  * The dyn_ftrace record's flags field is split into two parts.
 279  * the first part which is '0-FTRACE_REF_MAX' is a counter of
 280  * the number of callbacks that have registered the function that
 281  * the dyn_ftrace descriptor represents.
 282  *
 283  * The second part is a mask:
 284  *  ENABLED - the function is being traced
 285  *  REGS    - the record wants the function to save regs
 286  *  REGS_EN - the function is set up to save regs.
 287  *
 288  * When a new ftrace_ops is registered and wants a function to save
 289  * pt_regs, the rec->flag REGS is set. When the function has been
 290  * set up to save regs, the REG_EN flag is set. Once a function
 291  * starts saving regs it will do so until all ftrace_ops are removed
 292  * from tracing that function.
 293  */
 294 enum {
 295         FTRACE_FL_ENABLED       = (1UL << 31),
 296         FTRACE_FL_REGS          = (1UL << 30),
 297         FTRACE_FL_REGS_EN       = (1UL << 29),
 298         FTRACE_FL_TRAMP         = (1UL << 28),
 299         FTRACE_FL_TRAMP_EN      = (1UL << 27),
 300 };
 301
 302 #define FTRACE_REF_MAX_SHIFT    27
 303 #define FTRACE_FL_BITS          5
 304 #define FTRACE_FL_MASKED_BITS   ((1UL << FTRACE_FL_BITS) - 1)
 305 #define FTRACE_FL_MASK          (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
 306 #define FTRACE_REF_MAX          ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
 307
 308 #define ftrace_rec_count(rec)   ((rec)->flags & ~FTRACE_FL_MASK)
 309
 310 struct dyn_ftrace {
 311         unsigned long           ip; /* address of mcount call-site */
 312         unsigned long           flags;
 313         struct dyn_arch_ftrace  arch;
 314 };
 315
 316 int ftrace_force_update(void);
 317 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 318                          int remove, int reset);
 319 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 320                        int len, int reset);
 321 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 322                         int len, int reset);
 323 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 324 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 325 void ftrace_free_filter(struct ftrace_ops *ops);
 326
 327 int register_ftrace_command(struct ftrace_func_command *cmd);
 328 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 329
 330 enum {
 331         FTRACE_UPDATE_CALLS             = (1 << 0),
 332         FTRACE_DISABLE_CALLS            = (1 << 1),
 333         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
 334         FTRACE_START_FUNC_RET           = (1 << 3),
 335         FTRACE_STOP_FUNC_RET            = (1 << 4),
 336 };
 337
 338 /*
 339  * The FTRACE_UPDATE_* enum is used to pass information back
 340  * from the ftrace_update_record() and ftrace_test_record()
 341  * functions. These are called by the code update routines
 342  * to find out what is to be done for a given function.
 343  *
 344  *  IGNORE           - The function is already what we want it to be
 345  *  MAKE_CALL        - Start tracing the function
 346  *  MODIFY_CALL      - Stop saving regs for the function
 347  *  MAKE_NOP         - Stop tracing the function
 348  */
 349 enum {
 350         FTRACE_UPDATE_IGNORE,
 351         FTRACE_UPDATE_MAKE_CALL,
 352         FTRACE_UPDATE_MODIFY_CALL,
 353         FTRACE_UPDATE_MAKE_NOP,
 354 };
 355
 356 enum {
 357         FTRACE_ITER_FILTER      = (1 << 0),
 358         FTRACE_ITER_NOTRACE     = (1 << 1),
 359         FTRACE_ITER_PRINTALL    = (1 << 2),
 360         FTRACE_ITER_DO_HASH     = (1 << 3),
 361         FTRACE_ITER_HASH        = (1 << 4),
 362         FTRACE_ITER_ENABLED     = (1 << 5),
 363 };
 364
 365 void arch_ftrace_update_code(int command);
 366
 367 struct ftrace_rec_iter;
 368
 369 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
 370 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
 371 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
 372
 373 #define for_ftrace_rec_iter(iter)               \
 374         for (iter = ftrace_rec_iter_start();    \
 375              iter;                              \
 376              iter = ftrace_rec_iter_next(iter))
 377
 378
 379 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
 380 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
 381 void ftrace_run_stop_machine(int command);
 382 unsigned long ftrace_location(unsigned long ip);
 383 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
 384 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
 385
 386 extern ftrace_func_t ftrace_trace_function;
 387
 388 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
 389                   struct inode *inode, struct file *file);
 390 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 391                             size_t cnt, loff_t *ppos);
 392 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 393                              size_t cnt, loff_t *ppos);
 394 int ftrace_regex_release(struct inode *inode, struct file *file);
 395
 396 void __init
 397 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
 398
 399 /* defined in arch */
 400 extern int ftrace_ip_converted(unsigned long ip);
 401 extern int ftrace_dyn_arch_init(void);
 402 extern void ftrace_replace_code(int enable);
 403 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 404 extern void ftrace_caller(void);
 405 extern void ftrace_regs_caller(void);
 406 extern void ftrace_call(void);
 407 extern void ftrace_regs_call(void);
 408 extern void mcount_call(void);
 409
 410 void ftrace_modify_all_code(int command);
 411
 412 #ifndef FTRACE_ADDR
 413 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 414 #endif
 415
 416 #ifndef FTRACE_GRAPH_ADDR
 417 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
 418 #endif
 419
 420 #ifndef FTRACE_REGS_ADDR
 421 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 422 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
 423 #else
 424 # define FTRACE_REGS_ADDR FTRACE_ADDR
 425 #endif
 426 #endif
 427
 428 /*
 429  * If an arch would like functions that are only traced
 430  * by the function graph tracer to jump directly to its own
 431  * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
 432  * to be that address to jump to.
 433  */
 434 #ifndef FTRACE_GRAPH_TRAMP_ADDR
 435 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
 436 #endif
 437
 438 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 439 extern void ftrace_graph_caller(void);
 440 extern int ftrace_enable_ftrace_graph_caller(void);
 441 extern int ftrace_disable_ftrace_graph_caller(void);
 442 #else
 443 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 444 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 445 #endif
 446
 447 /**
 448  * ftrace_make_nop - convert code into nop
 449  * @mod: module structure if called by module load initialization
 450  * @rec: the mcount call site record
 451  * @addr: the address that the call site should be calling
 452  *
 453  * This is a very sensitive operation and great care needs
 454  * to be taken by the arch.  The operation should carefully
 455  * read the location, check to see if what is read is indeed
 456  * what we expect it to be, and then on success of the compare,
 457  * it should write to the location.
 458  *
 459  * The code segment at @rec->ip should be a caller to @addr
 460  *
 461  * Return must be:
 462  *  0 on success
 463  *  -EFAULT on error reading the location
 464  *  -EINVAL on a failed compare of the contents
 465  *  -EPERM  on error writing to the location
 466  * Any other value will be considered a failure.
 467  */
 468 extern int ftrace_make_nop(struct module *mod,
 469                            struct dyn_ftrace *rec, unsigned long addr);
 470
 471 /**
 472  * ftrace_make_call - convert a nop call site into a call to addr
 473  * @rec: the mcount call site record
 474  * @addr: the address that the call site should call
 475  *
 476  * This is a very sensitive operation and great care needs
 477  * to be taken by the arch.  The operation should carefully
 478  * read the location, check to see if what is read is indeed
 479  * what we expect it to be, and then on success of the compare,
 480  * it should write to the location.
 481  *
 482  * The code segment at @rec->ip should be a nop
 483  *
 484  * Return must be:
 485  *  0 on success
 486  *  -EFAULT on error reading the location
 487  *  -EINVAL on a failed compare of the contents
 488  *  -EPERM  on error writing to the location
 489  * Any other value will be considered a failure.
 490  */
 491 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 492
 493 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 494 /**
 495  * ftrace_modify_call - convert from one addr to another (no nop)
 496  * @rec: the mcount call site record
 497  * @old_addr: the address expected to be currently called to
 498  * @addr: the address to change to
 499  *
 500  * This is a very sensitive operation and great care needs
 501  * to be taken by the arch.  The operation should carefully
 502  * read the location, check to see if what is read is indeed
 503  * what we expect it to be, and then on success of the compare,
 504  * it should write to the location.
 505  *
 506  * The code segment at @rec->ip should be a caller to @old_addr
 507  *
 508  * Return must be:
 509  *  0 on success
 510  *  -EFAULT on error reading the location
 511  *  -EINVAL on a failed compare of the contents
 512  *  -EPERM  on error writing to the location
 513  * Any other value will be considered a failure.
 514  */
 515 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 516                               unsigned long addr);
 517 #else
 518 /* Should never be called */
 519 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 520                                      unsigned long addr)
 521 {
 522         return -EINVAL;
 523 }
 524 #endif
 525
 526 /* May be defined in arch */
 527 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 528
 529 extern int skip_trace(unsigned long ip);
 530 extern void ftrace_module_init(struct module *mod);
 531
 532 extern void ftrace_disable_daemon(void);
 533 extern void ftrace_enable_daemon(void);
 534 #else /* CONFIG_DYNAMIC_FTRACE */
 535 static inline int skip_trace(unsigned long ip) { return 0; }
 536 static inline int ftrace_force_update(void) { return 0; }
 537 static inline void ftrace_disable_daemon(void) { }
 538 static inline void ftrace_enable_daemon(void) { }
 539 static inline void ftrace_release_mod(struct module *mod) {}
 540 static inline void ftrace_module_init(struct module *mod) {}
 541 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
 542 {
 543         return -EINVAL;
 544 }
 545 static inline __init int unregister_ftrace_command(char *cmd_name)
 546 {
 547         return -EINVAL;
 548 }
 549 static inline int ftrace_text_reserved(const void *start, const void *end)
 550 {
 551         return 0;
 552 }
 553 static inline unsigned long ftrace_location(unsigned long ip)
 554 {
 555         return 0;
 556 }
 557
 558 /*
 559  * Again users of functions that have ftrace_ops may not
 560  * have them defined when ftrace is not enabled, but these
 561  * functions may still be called. Use a macro instead of inline.
 562  */
 563 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
 564 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
 565 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
 566 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
 567 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
 568 #define ftrace_free_filter(ops) do { } while (0)
 569
 570 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 571                             size_t cnt, loff_t *ppos) { return -ENODEV; }
 572 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 573                              size_t cnt, loff_t *ppos) { return -ENODEV; }
 574 static inline int
 575 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
 576 #endif /* CONFIG_DYNAMIC_FTRACE */
 577
 578 /* totally disable ftrace - can not re-enable after this */
 579 void ftrace_kill(void);
 580
 581 static inline void tracer_disable(void)
 582 {
 583 #ifdef CONFIG_FUNCTION_TRACER
 584         ftrace_enabled = 0;
 585 #endif
 586 }
 587
 588 /*
 589  * Ftrace disable/restore without lock. Some synchronization mechanism
 590  * must be used to prevent ftrace_enabled to be changed between
 591  * disable/restore.
 592  */
 593 static inline int __ftrace_enabled_save(void)
 594 {
 595 #ifdef CONFIG_FUNCTION_TRACER
 596         int saved_ftrace_enabled = ftrace_enabled;
 597         ftrace_enabled = 0;
 598         return saved_ftrace_enabled;
 599 #else
 600         return 0;
 601 #endif
 602 }
 603
 604 static inline void __ftrace_enabled_restore(int enabled)
 605 {
 606 #ifdef CONFIG_FUNCTION_TRACER
 607         ftrace_enabled = enabled;
 608 #endif
 609 }
 610
 611 /* All archs should have this, but we define it for consistency */
 612 #ifndef ftrace_return_address0
 613 # define ftrace_return_address0 __builtin_return_address(0)
 614 #endif
 615
 616 /* Archs may use other ways for ADDR1 and beyond */
 617 #ifndef ftrace_return_address
 618 # ifdef CONFIG_FRAME_POINTER
 619 #  define ftrace_return_address(n) __builtin_return_address(n)
 620 # else
 621 #  define ftrace_return_address(n) 0UL
 622 # endif
 623 #endif
 624
 625 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
 626 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
 627 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
 628 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
 629 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
 630 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
 631 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
 632
 633 #ifdef CONFIG_IRQSOFF_TRACER
 634   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 635   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 636 #else
 637   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
 638   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
 639 #endif
 640
 641 #ifdef CONFIG_PREEMPT_TRACER
 642   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 643   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 644 #else
 645 /*
 646  * Use defines instead of static inlines because some arches will make code out
 647  * of the CALLER_ADDR, when we really want these to be a real nop.
 648  */
 649 # define trace_preempt_on(a0, a1) do { } while (0)
 650 # define trace_preempt_off(a0, a1) do { } while (0)
 651 #endif
 652
 653 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 654 extern void ftrace_init(void);
 655 #else
 656 static inline void ftrace_init(void) { }
 657 #endif
 658
 659 /*
 660  * Structure that defines an entry function trace.
 661  */
 662 struct ftrace_graph_ent {
 663         unsigned long func; /* Current function */
 664         int depth;
 665 };
 666
 667 /*
 668  * Structure that defines a return function trace.
 669  */
 670 struct ftrace_graph_ret {
 671         unsigned long func; /* Current function */
 672         unsigned long long calltime;
 673         unsigned long long rettime;
 674         /* Number of functions that overran the depth limit for current task */
 675         unsigned long overrun;
 676         int depth;
 677 };
 678
 679 /* Type of the callback handlers for tracing function graph*/
 680 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 681 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 682
 683 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 684
 685 /* for init task */
 686 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
 687
 688 /*
 689  * Stack of return addresses for functions
 690  * of a thread.
 691  * Used in struct thread_info
 692  */
 693 struct ftrace_ret_stack {
 694         unsigned long ret;
 695         unsigned long func;
 696         unsigned long long calltime;
 697         unsigned long long subtime;
 698         unsigned long fp;
 699 };
 700
 701 /*
 702  * Primary handler of a function return.
 703  * It relays on ftrace_return_to_handler.
 704  * Defined in entry_32/64.S
 705  */
 706 extern void return_to_handler(void);
 707
 708 extern int
 709 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 710                          unsigned long frame_pointer);
 711
 712 /*
 713  * Sometimes we don't want to trace a function with the function
 714  * graph tracer but we want them to keep traced by the usual function
 715  * tracer if the function graph tracer is not configured.
 716  */
 717 #define __notrace_funcgraph             notrace
 718
 719 /*
 720  * We want to which function is an entrypoint of a hardirq.
 721  * That will help us to put a signal on output.
 722  */
 723 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 724
 725 /* Limits of hardirq entrypoints */
 726 extern char __irqentry_text_start[];
 727 extern char __irqentry_text_end[];
 728
 729 #define FTRACE_NOTRACE_DEPTH 65536
 730 #define FTRACE_RETFUNC_DEPTH 50
 731 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 732 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 733                                 trace_func_graph_ent_t entryfunc);
 734
 735 extern bool ftrace_graph_is_dead(void);
 736 extern void ftrace_graph_stop(void);
 737
 738 /* The current handlers in use */
 739 extern trace_func_graph_ret_t ftrace_graph_return;
 740 extern trace_func_graph_ent_t ftrace_graph_entry;
 741
 742 extern void unregister_ftrace_graph(void);
 743
 744 extern void ftrace_graph_init_task(struct task_struct *t);
 745 extern void ftrace_graph_exit_task(struct task_struct *t);
 746 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
 747
 748 static inline int task_curr_ret_stack(struct task_struct *t)
 749 {
 750         return t->curr_ret_stack;
 751 }
 752
 753 static inline void pause_graph_tracing(void)
 754 {
 755         atomic_inc(&current->tracing_graph_pause);
 756 }
 757
 758 static inline void unpause_graph_tracing(void)
 759 {
 760         atomic_dec(&current->tracing_graph_pause);
 761 }
 762 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 763
 764 #define __notrace_funcgraph
 765 #define __irq_entry
 766 #define INIT_FTRACE_GRAPH
 767
 768 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 769 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 770 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
 771
 772 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 773                           trace_func_graph_ent_t entryfunc)
 774 {
 775         return -1;
 776 }
 777 static inline void unregister_ftrace_graph(void) { }
 778
 779 static inline int task_curr_ret_stack(struct task_struct *tsk)
 780 {
 781         return -1;
 782 }
 783
 784 static inline void pause_graph_tracing(void) { }
 785 static inline void unpause_graph_tracing(void) { }
 786 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 787
 788 #ifdef CONFIG_TRACING
 789
 790 /* flags for current->trace */
 791 enum {
 792         TSK_TRACE_FL_TRACE_BIT  = 0,
 793         TSK_TRACE_FL_GRAPH_BIT  = 1,
 794 };
 795 enum {
 796         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 797         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 798 };
 799
 800 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 801 {
 802         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 803 }
 804
 805 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 806 {
 807         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 808 }
 809
 810 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 811 {
 812         return tsk->trace & TSK_TRACE_FL_TRACE;
 813 }
 814
 815 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 816 {
 817         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 818 }
 819
 820 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 821 {
 822         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 823 }
 824
 825 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 826 {
 827         return tsk->trace & TSK_TRACE_FL_GRAPH;
 828 }
 829
 830 enum ftrace_dump_mode;
 831
 832 extern enum ftrace_dump_mode ftrace_dump_on_oops;
 833
 834 extern void disable_trace_on_warning(void);
 835 extern int __disable_trace_on_warning;
 836
 837 #ifdef CONFIG_PREEMPT
 838 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
 839 #endif
 840
 841 #else /* CONFIG_TRACING */
 842 static inline void  disable_trace_on_warning(void) { }
 843 #endif /* CONFIG_TRACING */
 844
 845 #ifndef INIT_TRACE_RECURSION
 846 #define INIT_TRACE_RECURSION
 847 #endif
 848
 849 #ifdef CONFIG_FTRACE_SYSCALLS
 850
 851 unsigned long arch_syscall_addr(int nr);
 852
 853 #endif /* CONFIG_FTRACE_SYSCALLS */
 854
 855 #endif /* _LINUX_FTRACE_H */