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