include/linux/ftrace.h

   1 /*
   2  * Ftrace header.  For implementation details beyond the random comments
   3  * scattered below, see: Documentation/trace/ftrace-design.txt
   4  */
   5
   6 #ifndef _LINUX_FTRACE_H
   7 #define _LINUX_FTRACE_H
   8
   9 #include <linux/trace_clock.h>
  10 #include <linux/kallsyms.h>
  11 #include <linux/linkage.h>
  12 #include <linux/bitops.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/ktime.h>
  15 #include <linux/sched.h>
  16 #include <linux/types.h>
  17 #include <linux/init.h>
  18 #include <linux/fs.h>
  19
  20 #include <asm/ftrace.h>
  21
  22 /*
  23  * If the arch supports passing the variable contents of
  24  * function_trace_op as the third parameter back from the
  25  * mcount call, then the arch should define this as 1.
  26  */
  27 #ifndef ARCH_SUPPORTS_FTRACE_OPS
  28 #define ARCH_SUPPORTS_FTRACE_OPS 0
  29 #endif
  30
  31 /*
  32  * If the arch's mcount caller does not support all of ftrace's
  33  * features, then it must call an indirect function that
  34  * does. Or at least does enough to prevent any unwelcomed side effects.
  35  */
  36 #if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \
  37         !ARCH_SUPPORTS_FTRACE_OPS
  38 # define FTRACE_FORCE_LIST_FUNC 1
  39 #else
  40 # define FTRACE_FORCE_LIST_FUNC 0
  41 #endif
  42
  43
  44 struct module;
  45 struct ftrace_hash;
  46
  47 #ifdef CONFIG_FUNCTION_TRACER
  48
  49 extern int ftrace_enabled;
  50 extern int
  51 ftrace_enable_sysctl(struct ctl_table *table, int write,
  52                      void __user *buffer, size_t *lenp,
  53                      loff_t *ppos);
  54
  55 struct ftrace_ops;
  56
  57 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
  58                               struct ftrace_ops *op, struct pt_regs *regs);
  59
  60 /*
  61  * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
  62  * set in the flags member.
  63  *
  64  * ENABLED - set/unset when ftrace_ops is registered/unregistered
  65  * GLOBAL  - set manualy by ftrace_ops user to denote the ftrace_ops
  66  *           is part of the global tracers sharing the same filter
  67  *           via set_ftrace_* debugfs files.
  68  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
  69  *           allocated ftrace_ops which need special care
  70  * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
  71  *           could be controled by following calls:
  72  *             ftrace_function_local_enable
  73  *             ftrace_function_local_disable
  74  * SAVE_REGS - The ftrace_ops wants regs saved at each function called
  75  *            and passed to the callback. If this flag is set, but the
  76  *            architecture does not support passing regs
  77  *            (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
  78  *            ftrace_ops will fail to register, unless the next flag
  79  *            is set.
  80  * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
  81  *            handler can handle an arch that does not save regs
  82  *            (the handler tests if regs == NULL), then it can set
  83  *            this flag instead. It will not fail registering the ftrace_ops
  84  *            but, the regs field will be NULL if the arch does not support
  85  *            passing regs to the handler.
  86  *            Note, if this flag is set, the SAVE_REGS flag will automatically
  87  *            get set upon registering the ftrace_ops, if the arch supports it.
  88  * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
  89  *            that the call back has its own recursion protection. If it does
  90  *            not set this, then the ftrace infrastructure will add recursion
  91  *            protection for the caller.
  92  * STUB   - The ftrace_ops is just a place holder.
  93  * INITIALIZED - The ftrace_ops has already been initialized (first use time
  94  *            register_ftrace_function() is called, it will initialized the ops)
  95  * DELETED - The ops are being deleted, do not let them be registered again.
  96  */
  97 enum {
  98         FTRACE_OPS_FL_ENABLED                   = 1 << 0,
  99         FTRACE_OPS_FL_GLOBAL                    = 1 << 1,
 100         FTRACE_OPS_FL_DYNAMIC                   = 1 << 2,
 101         FTRACE_OPS_FL_CONTROL                   = 1 << 3,
 102         FTRACE_OPS_FL_SAVE_REGS                 = 1 << 4,
 103         FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED    = 1 << 5,
 104         FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 6,
 105         FTRACE_OPS_FL_STUB                      = 1 << 7,
 106         FTRACE_OPS_FL_INITIALIZED               = 1 << 8,
 107         FTRACE_OPS_FL_DELETED                   = 1 << 9,
 108 };
 109
 110 /*
 111  * Note, ftrace_ops can be referenced outside of RCU protection.
 112  * (Although, for perf, the control ops prevent that). If ftrace_ops is
 113  * allocated and not part of kernel core data, the unregistering of it will
 114  * perform a scheduling on all CPUs to make sure that there are no more users.
 115  * Depending on the load of the system that may take a bit of time.
 116  *
 117  * Any private data added must also take care not to be freed and if private
 118  * data is added to a ftrace_ops that is in core code, the user of the
 119  * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
 120  */
 121 struct ftrace_ops {
 122         ftrace_func_t                   func;
 123         struct ftrace_ops               *next;
 124         unsigned long                   flags;
 125         int __percpu                    *disabled;
 126         void                            *private;
 127 #ifdef CONFIG_DYNAMIC_FTRACE
 128         struct ftrace_hash              *notrace_hash;
 129         struct ftrace_hash              *filter_hash;
 130         struct mutex                    regex_lock;
 131 #endif
 132 };
 133
 134 extern int function_trace_stop;
 135
 136 /*
 137  * Type of the current tracing.
 138  */
 139 enum ftrace_tracing_type_t {
 140         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
 141         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
 142 };
 143
 144 /* Current tracing type, default is FTRACE_TYPE_ENTER */
 145 extern enum ftrace_tracing_type_t ftrace_tracing_type;
 146
 147 /**
 148  * ftrace_stop - stop function tracer.
 149  *
 150  * A quick way to stop the function tracer. Note this an on off switch,
 151  * it is not something that is recursive like preempt_disable.
 152  * This does not disable the calling of mcount, it only stops the
 153  * calling of functions from mcount.
 154  */
 155 static inline void ftrace_stop(void)
 156 {
 157         function_trace_stop = 1;
 158 }
 159
 160 /**
 161  * ftrace_start - start the function tracer.
 162  *
 163  * This function is the inverse of ftrace_stop. This does not enable
 164  * the function tracing if the function tracer is disabled. This only
 165  * sets the function tracer flag to continue calling the functions
 166  * from mcount.
 167  */
 168 static inline void ftrace_start(void)
 169 {
 170         function_trace_stop = 0;
 171 }
 172
 173 /*
 174  * The ftrace_ops must be a static and should also
 175  * be read_mostly.  These functions do modify read_mostly variables
 176  * so use them sparely. Never free an ftrace_op or modify the
 177  * next pointer after it has been registered. Even after unregistering
 178  * it, the next pointer may still be used internally.
 179  */
 180 int register_ftrace_function(struct ftrace_ops *ops);
 181 int unregister_ftrace_function(struct ftrace_ops *ops);
 182 void clear_ftrace_function(void);
 183
 184 /**
 185  * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
 186  *
 187  * This function enables tracing on current cpu by decreasing
 188  * the per cpu control variable.
 189  * It must be called with preemption disabled and only on ftrace_ops
 190  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 191  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 192  */
 193 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
 194 {
 195         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 196                 return;
 197
 198         (*this_cpu_ptr(ops->disabled))--;
 199 }
 200
 201 /**
 202  * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
 203  *
 204  * This function enables tracing on current cpu by decreasing
 205  * the per cpu control variable.
 206  * It must be called with preemption disabled and only on ftrace_ops
 207  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 208  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 209  */
 210 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
 211 {
 212         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
 213                 return;
 214
 215         (*this_cpu_ptr(ops->disabled))++;
 216 }
 217
 218 /**
 219  * ftrace_function_local_disabled - returns ftrace_ops disabled value
 220  *                                  on current cpu
 221  *
 222  * This function returns value of ftrace_ops::disabled on current cpu.
 223  * It must be called with preemption disabled and only on ftrace_ops
 224  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
 225  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
 226  */
 227 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
 228 {
 229         WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
 230         return *this_cpu_ptr(ops->disabled);
 231 }
 232
 233 extern void ftrace_stub(unsigned long a0, unsigned long a1,
 234                         struct ftrace_ops *op, struct pt_regs *regs);
 235
 236 #else /* !CONFIG_FUNCTION_TRACER */
 237 /*
 238  * (un)register_ftrace_function must be a macro since the ops parameter
 239  * must not be evaluated.
 240  */
 241 #define register_ftrace_function(ops) ({ 0; })
 242 #define unregister_ftrace_function(ops) ({ 0; })
 243 static inline int ftrace_nr_registered_ops(void)
 244 {
 245         return 0;
 246 }
 247 static inline void clear_ftrace_function(void) { }
 248 static inline void ftrace_kill(void) { }
 249 static inline void ftrace_stop(void) { }
 250 static inline void ftrace_start(void) { }
 251 #endif /* CONFIG_FUNCTION_TRACER */
 252
 253 #ifdef CONFIG_STACK_TRACER
 254 extern int stack_tracer_enabled;
 255 int
 256 stack_trace_sysctl(struct ctl_table *table, int write,
 257                    void __user *buffer, size_t *lenp,
 258                    loff_t *ppos);
 259 #endif
 260
 261 struct ftrace_func_command {
 262         struct list_head        list;
 263         char                    *name;
 264         int                     (*func)(struct ftrace_hash *hash,
 265                                         char *func, char *cmd,
 266                                         char *params, int enable);
 267 };
 268
 269 #ifdef CONFIG_DYNAMIC_FTRACE
 270
 271 int ftrace_arch_code_modify_prepare(void);
 272 int ftrace_arch_code_modify_post_process(void);
 273
 274 void ftrace_bug(int err, unsigned long ip);
 275
 276 struct seq_file;
 277
 278 struct ftrace_probe_ops {
 279         void                    (*func)(unsigned long ip,
 280                                         unsigned long parent_ip,
 281                                         void **data);
 282         int                     (*init)(struct ftrace_probe_ops *ops,
 283                                         unsigned long ip, void **data);
 284         void                    (*free)(struct ftrace_probe_ops *ops,
 285                                         unsigned long ip, void **data);
 286         int                     (*print)(struct seq_file *m,
 287                                          unsigned long ip,
 288                                          struct ftrace_probe_ops *ops,
 289                                          void *data);
 290 };
 291
 292 extern int
 293 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 294                               void *data);
 295 extern void
 296 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 297                                 void *data);
 298 extern void
 299 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 300 extern void unregister_ftrace_function_probe_all(char *glob);
 301
 302 extern int ftrace_text_reserved(const void *start, const void *end);
 303
 304 extern int ftrace_nr_registered_ops(void);
 305
 306 /*
 307  * The dyn_ftrace record's flags field is split into two parts.
 308  * the first part which is '0-FTRACE_REF_MAX' is a counter of
 309  * the number of callbacks that have registered the function that
 310  * the dyn_ftrace descriptor represents.
 311  *
 312  * The second part is a mask:
 313  *  ENABLED - the function is being traced
 314  *  REGS    - the record wants the function to save regs
 315  *  REGS_EN - the function is set up to save regs.
 316  *
 317  * When a new ftrace_ops is registered and wants a function to save
 318  * pt_regs, the rec->flag REGS is set. When the function has been
 319  * set up to save regs, the REG_EN flag is set. Once a function
 320  * starts saving regs it will do so until all ftrace_ops are removed
 321  * from tracing that function.
 322  */
 323 enum {
 324         FTRACE_FL_ENABLED       = (1UL << 29),
 325         FTRACE_FL_REGS          = (1UL << 30),
 326         FTRACE_FL_REGS_EN       = (1UL << 31)
 327 };
 328
 329 #define FTRACE_FL_MASK          (0x7UL << 29)
 330 #define FTRACE_REF_MAX          ((1UL << 29) - 1)
 331
 332 struct dyn_ftrace {
 333         unsigned long           ip; /* address of mcount call-site */
 334         unsigned long           flags;
 335         struct dyn_arch_ftrace  arch;
 336 };
 337
 338 int ftrace_force_update(void);
 339 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 340                          int remove, int reset);
 341 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
 342                        int len, int reset);
 343 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
 344                         int len, int reset);
 345 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
 346 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 347 void ftrace_free_filter(struct ftrace_ops *ops);
 348
 349 int register_ftrace_command(struct ftrace_func_command *cmd);
 350 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 351
 352 enum {
 353         FTRACE_UPDATE_CALLS             = (1 << 0),
 354         FTRACE_DISABLE_CALLS            = (1 << 1),
 355         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
 356         FTRACE_START_FUNC_RET           = (1 << 3),
 357         FTRACE_STOP_FUNC_RET            = (1 << 4),
 358 };
 359
 360 /*
 361  * The FTRACE_UPDATE_* enum is used to pass information back
 362  * from the ftrace_update_record() and ftrace_test_record()
 363  * functions. These are called by the code update routines
 364  * to find out what is to be done for a given function.
 365  *
 366  *  IGNORE           - The function is already what we want it to be
 367  *  MAKE_CALL        - Start tracing the function
 368  *  MODIFY_CALL      - Stop saving regs for the function
 369  *  MODIFY_CALL_REGS - Start saving regs for the function
 370  *  MAKE_NOP         - Stop tracing the function
 371  */
 372 enum {
 373         FTRACE_UPDATE_IGNORE,
 374         FTRACE_UPDATE_MAKE_CALL,
 375         FTRACE_UPDATE_MODIFY_CALL,
 376         FTRACE_UPDATE_MODIFY_CALL_REGS,
 377         FTRACE_UPDATE_MAKE_NOP,
 378 };
 379
 380 enum {
 381         FTRACE_ITER_FILTER      = (1 << 0),
 382         FTRACE_ITER_NOTRACE     = (1 << 1),
 383         FTRACE_ITER_PRINTALL    = (1 << 2),
 384         FTRACE_ITER_DO_HASH     = (1 << 3),
 385         FTRACE_ITER_HASH        = (1 << 4),
 386         FTRACE_ITER_ENABLED     = (1 << 5),
 387 };
 388
 389 void arch_ftrace_update_code(int command);
 390
 391 struct ftrace_rec_iter;
 392
 393 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
 394 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
 395 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
 396
 397 #define for_ftrace_rec_iter(iter)               \
 398         for (iter = ftrace_rec_iter_start();    \
 399              iter;                              \
 400              iter = ftrace_rec_iter_next(iter))
 401
 402
 403 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
 404 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
 405 void ftrace_run_stop_machine(int command);
 406 unsigned long ftrace_location(unsigned long ip);
 407
 408 extern ftrace_func_t ftrace_trace_function;
 409
 410 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
 411                   struct inode *inode, struct file *file);
 412 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 413                             size_t cnt, loff_t *ppos);
 414 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 415                              size_t cnt, loff_t *ppos);
 416 int ftrace_regex_release(struct inode *inode, struct file *file);
 417
 418 void __init
 419 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
 420
 421 /* defined in arch */
 422 extern int ftrace_ip_converted(unsigned long ip);
 423 extern int ftrace_dyn_arch_init(void);
 424 extern void ftrace_replace_code(int enable);
 425 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 426 extern void ftrace_caller(void);
 427 extern void ftrace_regs_caller(void);
 428 extern void ftrace_call(void);
 429 extern void ftrace_regs_call(void);
 430 extern void mcount_call(void);
 431
 432 void ftrace_modify_all_code(int command);
 433
 434 #ifndef FTRACE_ADDR
 435 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 436 #endif
 437
 438 #ifndef FTRACE_REGS_ADDR
 439 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 440 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
 441 #else
 442 # define FTRACE_REGS_ADDR FTRACE_ADDR
 443 #endif
 444 #endif
 445
 446 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 447 extern void ftrace_graph_caller(void);
 448 extern int ftrace_enable_ftrace_graph_caller(void);
 449 extern int ftrace_disable_ftrace_graph_caller(void);
 450 #else
 451 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 452 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 453 #endif
 454
 455 /**
 456  * ftrace_make_nop - convert code into nop
 457  * @mod: module structure if called by module load initialization
 458  * @rec: the mcount call site record
 459  * @addr: the address that the call site should be calling
 460  *
 461  * This is a very sensitive operation and great care needs
 462  * to be taken by the arch.  The operation should carefully
 463  * read the location, check to see if what is read is indeed
 464  * what we expect it to be, and then on success of the compare,
 465  * it should write to the location.
 466  *
 467  * The code segment at @rec->ip should be a caller to @addr
 468  *
 469  * Return must be:
 470  *  0 on success
 471  *  -EFAULT on error reading the location
 472  *  -EINVAL on a failed compare of the contents
 473  *  -EPERM  on error writing to the location
 474  * Any other value will be considered a failure.
 475  */
 476 extern int ftrace_make_nop(struct module *mod,
 477                            struct dyn_ftrace *rec, unsigned long addr);
 478
 479 /**
 480  * ftrace_make_call - convert a nop call site into a call to addr
 481  * @rec: the mcount call site record
 482  * @addr: the address that the call site should call
 483  *
 484  * This is a very sensitive operation and great care needs
 485  * to be taken by the arch.  The operation should carefully
 486  * read the location, check to see if what is read is indeed
 487  * what we expect it to be, and then on success of the compare,
 488  * it should write to the location.
 489  *
 490  * The code segment at @rec->ip should be a nop
 491  *
 492  * Return must be:
 493  *  0 on success
 494  *  -EFAULT on error reading the location
 495  *  -EINVAL on a failed compare of the contents
 496  *  -EPERM  on error writing to the location
 497  * Any other value will be considered a failure.
 498  */
 499 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 500
 501 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 502 /**
 503  * ftrace_modify_call - convert from one addr to another (no nop)
 504  * @rec: the mcount call site record
 505  * @old_addr: the address expected to be currently called to
 506  * @addr: the address to change to
 507  *
 508  * This is a very sensitive operation and great care needs
 509  * to be taken by the arch.  The operation should carefully
 510  * read the location, check to see if what is read is indeed
 511  * what we expect it to be, and then on success of the compare,
 512  * it should write to the location.
 513  *
 514  * The code segment at @rec->ip should be a caller to @old_addr
 515  *
 516  * Return must be:
 517  *  0 on success
 518  *  -EFAULT on error reading the location
 519  *  -EINVAL on a failed compare of the contents
 520  *  -EPERM  on error writing to the location
 521  * Any other value will be considered a failure.
 522  */
 523 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 524                               unsigned long addr);
 525 #else
 526 /* Should never be called */
 527 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 528                                      unsigned long addr)
 529 {
 530         return -EINVAL;
 531 }
 532 #endif
 533
 534 /* May be defined in arch */
 535 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 536
 537 extern int skip_trace(unsigned long ip);
 538 extern void ftrace_module_init(struct module *mod);
 539
 540 extern void ftrace_disable_daemon(void);
 541 extern void ftrace_enable_daemon(void);
 542 #else /* CONFIG_DYNAMIC_FTRACE */
 543 static inline int skip_trace(unsigned long ip) { return 0; }
 544 static inline int ftrace_force_update(void) { return 0; }
 545 static inline void ftrace_disable_daemon(void) { }
 546 static inline void ftrace_enable_daemon(void) { }
 547 static inline void ftrace_release_mod(struct module *mod) {}
 548 static inline void ftrace_module_init(struct module *mod) {}
 549 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
 550 {
 551         return -EINVAL;
 552 }
 553 static inline __init int unregister_ftrace_command(char *cmd_name)
 554 {
 555         return -EINVAL;
 556 }
 557 static inline int ftrace_text_reserved(const void *start, const void *end)
 558 {
 559         return 0;
 560 }
 561 static inline unsigned long ftrace_location(unsigned long ip)
 562 {
 563         return 0;
 564 }
 565
 566 /*
 567  * Again users of functions that have ftrace_ops may not
 568  * have them defined when ftrace is not enabled, but these
 569  * functions may still be called. Use a macro instead of inline.
 570  */
 571 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
 572 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
 573 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
 574 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
 575 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
 576 #define ftrace_free_filter(ops) do { } while (0)
 577
 578 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
 579                             size_t cnt, loff_t *ppos) { return -ENODEV; }
 580 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
 581                              size_t cnt, loff_t *ppos) { return -ENODEV; }
 582 static inline int
 583 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
 584 #endif /* CONFIG_DYNAMIC_FTRACE */
 585
 586 /* totally disable ftrace - can not re-enable after this */
 587 void ftrace_kill(void);
 588
 589 static inline void tracer_disable(void)
 590 {
 591 #ifdef CONFIG_FUNCTION_TRACER
 592         ftrace_enabled = 0;
 593 #endif
 594 }
 595
 596 /*
 597  * Ftrace disable/restore without lock. Some synchronization mechanism
 598  * must be used to prevent ftrace_enabled to be changed between
 599  * disable/restore.
 600  */
 601 static inline int __ftrace_enabled_save(void)
 602 {
 603 #ifdef CONFIG_FUNCTION_TRACER
 604         int saved_ftrace_enabled = ftrace_enabled;
 605         ftrace_enabled = 0;
 606         return saved_ftrace_enabled;
 607 #else
 608         return 0;
 609 #endif
 610 }
 611
 612 static inline void __ftrace_enabled_restore(int enabled)
 613 {
 614 #ifdef CONFIG_FUNCTION_TRACER
 615         ftrace_enabled = enabled;
 616 #endif
 617 }
 618
 619 #ifndef HAVE_ARCH_CALLER_ADDR
 620 # ifdef CONFIG_FRAME_POINTER
 621 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 622 #  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 623 #  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 624 #  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 625 #  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 626 #  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 627 #  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 628 # else
 629 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 630 #  define CALLER_ADDR1 0UL
 631 #  define CALLER_ADDR2 0UL
 632 #  define CALLER_ADDR3 0UL
 633 #  define CALLER_ADDR4 0UL
 634 #  define CALLER_ADDR5 0UL
 635 #  define CALLER_ADDR6 0UL
 636 # endif
 637 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
 638
 639 #ifdef CONFIG_IRQSOFF_TRACER
 640   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 641   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 642 #else
 643   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
 644   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
 645 #endif
 646
 647 #ifdef CONFIG_PREEMPT_TRACER
 648   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 649   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 650 #else
 651 /*
 652  * Use defines instead of static inlines because some arches will make code out
 653  * of the CALLER_ADDR, when we really want these to be a real nop.
 654  */
 655 # define trace_preempt_on(a0, a1) do { } while (0)
 656 # define trace_preempt_off(a0, a1) do { } while (0)
 657 #endif
 658
 659 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 660 extern void ftrace_init(void);
 661 #else
 662 static inline void ftrace_init(void) { }
 663 #endif
 664
 665 /*
 666  * Structure that defines an entry function trace.
 667  */
 668 struct ftrace_graph_ent {
 669         unsigned long func; /* Current function */
 670         int depth;
 671 };
 672
 673 /*
 674  * Structure that defines a return function trace.
 675  */
 676 struct ftrace_graph_ret {
 677         unsigned long func; /* Current function */
 678         unsigned long long calltime;
 679         unsigned long long rettime;
 680         /* Number of functions that overran the depth limit for current task */
 681         unsigned long overrun;
 682         int depth;
 683 };
 684
 685 /* Type of the callback handlers for tracing function graph*/
 686 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 687 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 688
 689 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 690
 691 /* for init task */
 692 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
 693
 694 /*
 695  * Stack of return addresses for functions
 696  * of a thread.
 697  * Used in struct thread_info
 698  */
 699 struct ftrace_ret_stack {
 700         unsigned long ret;
 701         unsigned long func;
 702         unsigned long long calltime;
 703         unsigned long long subtime;
 704         unsigned long fp;
 705 };
 706
 707 /*
 708  * Primary handler of a function return.
 709  * It relays on ftrace_return_to_handler.
 710  * Defined in entry_32/64.S
 711  */
 712 extern void return_to_handler(void);
 713
 714 extern int
 715 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 716                          unsigned long frame_pointer);
 717
 718 /*
 719  * Sometimes we don't want to trace a function with the function
 720  * graph tracer but we want them to keep traced by the usual function
 721  * tracer if the function graph tracer is not configured.
 722  */
 723 #define __notrace_funcgraph             notrace
 724
 725 /*
 726  * We want to which function is an entrypoint of a hardirq.
 727  * That will help us to put a signal on output.
 728  */
 729 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 730
 731 /* Limits of hardirq entrypoints */
 732 extern char __irqentry_text_start[];
 733 extern char __irqentry_text_end[];
 734
 735 #define FTRACE_NOTRACE_DEPTH 65536
 736 #define FTRACE_RETFUNC_DEPTH 50
 737 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 738 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 739                                 trace_func_graph_ent_t entryfunc);
 740
 741 extern void ftrace_graph_stop(void);
 742
 743 /* The current handlers in use */
 744 extern trace_func_graph_ret_t ftrace_graph_return;
 745 extern trace_func_graph_ent_t ftrace_graph_entry;
 746
 747 extern void unregister_ftrace_graph(void);
 748
 749 extern void ftrace_graph_init_task(struct task_struct *t);
 750 extern void ftrace_graph_exit_task(struct task_struct *t);
 751 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
 752
 753 static inline int task_curr_ret_stack(struct task_struct *t)
 754 {
 755         return t->curr_ret_stack;
 756 }
 757
 758 static inline void pause_graph_tracing(void)
 759 {
 760         atomic_inc(&current->tracing_graph_pause);
 761 }
 762
 763 static inline void unpause_graph_tracing(void)
 764 {
 765         atomic_dec(&current->tracing_graph_pause);
 766 }
 767 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 768
 769 #define __notrace_funcgraph
 770 #define __irq_entry
 771 #define INIT_FTRACE_GRAPH
 772
 773 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 774 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 775 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
 776
 777 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 778                           trace_func_graph_ent_t entryfunc)
 779 {
 780         return -1;
 781 }
 782 static inline void unregister_ftrace_graph(void) { }
 783
 784 static inline int task_curr_ret_stack(struct task_struct *tsk)
 785 {
 786         return -1;
 787 }
 788
 789 static inline void pause_graph_tracing(void) { }
 790 static inline void unpause_graph_tracing(void) { }
 791 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 792
 793 #ifdef CONFIG_TRACING
 794
 795 /* flags for current->trace */
 796 enum {
 797         TSK_TRACE_FL_TRACE_BIT  = 0,
 798         TSK_TRACE_FL_GRAPH_BIT  = 1,
 799 };
 800 enum {
 801         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 802         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 803 };
 804
 805 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 806 {
 807         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 808 }
 809
 810 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 811 {
 812         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 813 }
 814
 815 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 816 {
 817         return tsk->trace & TSK_TRACE_FL_TRACE;
 818 }
 819
 820 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 821 {
 822         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 823 }
 824
 825 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 826 {
 827         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 828 }
 829
 830 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 831 {
 832         return tsk->trace & TSK_TRACE_FL_GRAPH;
 833 }
 834
 835 enum ftrace_dump_mode;
 836
 837 extern enum ftrace_dump_mode ftrace_dump_on_oops;
 838
 839 extern void disable_trace_on_warning(void);
 840 extern int __disable_trace_on_warning;
 841
 842 #ifdef CONFIG_PREEMPT
 843 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
 844 #endif
 845
 846 #else /* CONFIG_TRACING */
 847 static inline void  disable_trace_on_warning(void) { }
 848 #endif /* CONFIG_TRACING */
 849
 850 #ifndef INIT_TRACE_RECURSION
 851 #define INIT_TRACE_RECURSION
 852 #endif
 853
 854 #ifdef CONFIG_FTRACE_SYSCALLS
 855
 856 unsigned long arch_syscall_addr(int nr);
 857
 858 #endif /* CONFIG_FTRACE_SYSCALLS */
 859
 860 #endif /* _LINUX_FTRACE_H */