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