include/linux/ftrace.h

   1 #ifndef _LINUX_FTRACE_H
   2 #define _LINUX_FTRACE_H
   3
   4 #include <linux/linkage.h>
   5 #include <linux/fs.h>
   6 #include <linux/ktime.h>
   7 #include <linux/init.h>
   8 #include <linux/types.h>
   9 #include <linux/module.h>
  10 #include <linux/kallsyms.h>
  11 #include <linux/bitops.h>
  12 #include <linux/sched.h>
  13
  14 #ifdef CONFIG_FUNCTION_TRACER
  15
  16 extern int ftrace_enabled;
  17 extern int
  18 ftrace_enable_sysctl(struct ctl_table *table, int write,
  19                      struct file *filp, void __user *buffer, size_t *lenp,
  20                      loff_t *ppos);
  21
  22 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
  23
  24 struct ftrace_ops {
  25         ftrace_func_t     func;
  26         struct ftrace_ops *next;
  27 };
  28
  29 extern int function_trace_stop;
  30
  31 /*
  32  * Type of the current tracing.
  33  */
  34 enum ftrace_tracing_type_t {
  35         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
  36         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
  37 };
  38
  39 /* Current tracing type, default is FTRACE_TYPE_ENTER */
  40 extern enum ftrace_tracing_type_t ftrace_tracing_type;
  41
  42 /**
  43  * ftrace_stop - stop function tracer.
  44  *
  45  * A quick way to stop the function tracer. Note this an on off switch,
  46  * it is not something that is recursive like preempt_disable.
  47  * This does not disable the calling of mcount, it only stops the
  48  * calling of functions from mcount.
  49  */
  50 static inline void ftrace_stop(void)
  51 {
  52         function_trace_stop = 1;
  53 }
  54
  55 /**
  56  * ftrace_start - start the function tracer.
  57  *
  58  * This function is the inverse of ftrace_stop. This does not enable
  59  * the function tracing if the function tracer is disabled. This only
  60  * sets the function tracer flag to continue calling the functions
  61  * from mcount.
  62  */
  63 static inline void ftrace_start(void)
  64 {
  65         function_trace_stop = 0;
  66 }
  67
  68 /*
  69  * The ftrace_ops must be a static and should also
  70  * be read_mostly.  These functions do modify read_mostly variables
  71  * so use them sparely. Never free an ftrace_op or modify the
  72  * next pointer after it has been registered. Even after unregistering
  73  * it, the next pointer may still be used internally.
  74  */
  75 int register_ftrace_function(struct ftrace_ops *ops);
  76 int unregister_ftrace_function(struct ftrace_ops *ops);
  77 void clear_ftrace_function(void);
  78
  79 extern void ftrace_stub(unsigned long a0, unsigned long a1);
  80
  81 #else /* !CONFIG_FUNCTION_TRACER */
  82 # define register_ftrace_function(ops) do { } while (0)
  83 # define unregister_ftrace_function(ops) do { } while (0)
  84 # define clear_ftrace_function(ops) do { } while (0)
  85 static inline void ftrace_kill(void) { }
  86 static inline void ftrace_stop(void) { }
  87 static inline void ftrace_start(void) { }
  88 #endif /* CONFIG_FUNCTION_TRACER */
  89
  90 #ifdef CONFIG_STACK_TRACER
  91 extern int stack_tracer_enabled;
  92 int
  93 stack_trace_sysctl(struct ctl_table *table, int write,
  94                    struct file *file, void __user *buffer, size_t *lenp,
  95                    loff_t *ppos);
  96 #endif
  97
  98 struct ftrace_func_command {
  99         struct list_head        list;
 100         char                    *name;
 101         int                     (*func)(char *func, char *cmd,
 102                                         char *params, int enable);
 103 };
 104
 105 #ifdef CONFIG_DYNAMIC_FTRACE
 106 /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
 107 #include <asm/ftrace.h>
 108
 109 int ftrace_arch_code_modify_prepare(void);
 110 int ftrace_arch_code_modify_post_process(void);
 111
 112 struct seq_file;
 113
 114 struct ftrace_probe_ops {
 115         void                    (*func)(unsigned long ip,
 116                                         unsigned long parent_ip,
 117                                         void **data);
 118         int                     (*callback)(unsigned long ip, void **data);
 119         void                    (*free)(void **data);
 120         int                     (*print)(struct seq_file *m,
 121                                          unsigned long ip,
 122                                          struct ftrace_probe_ops *ops,
 123                                          void *data);
 124 };
 125
 126 extern int
 127 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 128                               void *data);
 129 extern void
 130 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 131                                 void *data);
 132 extern void
 133 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 134 extern void unregister_ftrace_function_probe_all(char *glob);
 135
 136 enum {
 137         FTRACE_FL_FREE          = (1 << 0),
 138         FTRACE_FL_FAILED        = (1 << 1),
 139         FTRACE_FL_FILTER        = (1 << 2),
 140         FTRACE_FL_ENABLED       = (1 << 3),
 141         FTRACE_FL_NOTRACE       = (1 << 4),
 142         FTRACE_FL_CONVERTED     = (1 << 5),
 143         FTRACE_FL_FROZEN        = (1 << 6),
 144 };
 145
 146 struct dyn_ftrace {
 147         struct list_head        list;
 148         unsigned long           ip; /* address of mcount call-site */
 149         unsigned long           flags;
 150         struct dyn_arch_ftrace  arch;
 151 };
 152
 153 int ftrace_force_update(void);
 154 void ftrace_set_filter(unsigned char *buf, int len, int reset);
 155
 156 int register_ftrace_command(struct ftrace_func_command *cmd);
 157 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 158
 159 /* defined in arch */
 160 extern int ftrace_ip_converted(unsigned long ip);
 161 extern int ftrace_dyn_arch_init(void *data);
 162 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 163 extern void ftrace_caller(void);
 164 extern void ftrace_call(void);
 165 extern void mcount_call(void);
 166
 167 #ifndef FTRACE_ADDR
 168 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 169 #endif
 170 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 171 extern void ftrace_graph_caller(void);
 172 extern int ftrace_enable_ftrace_graph_caller(void);
 173 extern int ftrace_disable_ftrace_graph_caller(void);
 174 #else
 175 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 176 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 177 #endif
 178
 179 /**
 180  * ftrace_make_nop - convert code into nop
 181  * @mod: module structure if called by module load initialization
 182  * @rec: the mcount call site record
 183  * @addr: the address that the call site should be calling
 184  *
 185  * This is a very sensitive operation and great care needs
 186  * to be taken by the arch.  The operation should carefully
 187  * read the location, check to see if what is read is indeed
 188  * what we expect it to be, and then on success of the compare,
 189  * it should write to the location.
 190  *
 191  * The code segment at @rec->ip should be a caller to @addr
 192  *
 193  * Return must be:
 194  *  0 on success
 195  *  -EFAULT on error reading the location
 196  *  -EINVAL on a failed compare of the contents
 197  *  -EPERM  on error writing to the location
 198  * Any other value will be considered a failure.
 199  */
 200 extern int ftrace_make_nop(struct module *mod,
 201                            struct dyn_ftrace *rec, unsigned long addr);
 202
 203 /**
 204  * ftrace_make_call - convert a nop call site into a call to addr
 205  * @rec: the mcount call site record
 206  * @addr: the address that the call site should call
 207  *
 208  * This is a very sensitive operation and great care needs
 209  * to be taken by the arch.  The operation should carefully
 210  * read the location, check to see if what is read is indeed
 211  * what we expect it to be, and then on success of the compare,
 212  * it should write to the location.
 213  *
 214  * The code segment at @rec->ip should be a nop
 215  *
 216  * Return must be:
 217  *  0 on success
 218  *  -EFAULT on error reading the location
 219  *  -EINVAL on a failed compare of the contents
 220  *  -EPERM  on error writing to the location
 221  * Any other value will be considered a failure.
 222  */
 223 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 224
 225
 226 /* May be defined in arch */
 227 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 228
 229 extern int skip_trace(unsigned long ip);
 230
 231 extern void ftrace_release(void *start, unsigned long size);
 232
 233 extern void ftrace_disable_daemon(void);
 234 extern void ftrace_enable_daemon(void);
 235 #else
 236 # define skip_trace(ip)                         ({ 0; })
 237 # define ftrace_force_update()                  ({ 0; })
 238 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
 239 # define ftrace_disable_daemon()                do { } while (0)
 240 # define ftrace_enable_daemon()                 do { } while (0)
 241 static inline void ftrace_release(void *start, unsigned long size) { }
 242 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
 243 {
 244         return -EINVAL;
 245 }
 246 static inline int unregister_ftrace_command(char *cmd_name)
 247 {
 248         return -EINVAL;
 249 }
 250 #endif /* CONFIG_DYNAMIC_FTRACE */
 251
 252 /* totally disable ftrace - can not re-enable after this */
 253 void ftrace_kill(void);
 254
 255 static inline void tracer_disable(void)
 256 {
 257 #ifdef CONFIG_FUNCTION_TRACER
 258         ftrace_enabled = 0;
 259 #endif
 260 }
 261
 262 /*
 263  * Ftrace disable/restore without lock. Some synchronization mechanism
 264  * must be used to prevent ftrace_enabled to be changed between
 265  * disable/restore.
 266  */
 267 static inline int __ftrace_enabled_save(void)
 268 {
 269 #ifdef CONFIG_FUNCTION_TRACER
 270         int saved_ftrace_enabled = ftrace_enabled;
 271         ftrace_enabled = 0;
 272         return saved_ftrace_enabled;
 273 #else
 274         return 0;
 275 #endif
 276 }
 277
 278 static inline void __ftrace_enabled_restore(int enabled)
 279 {
 280 #ifdef CONFIG_FUNCTION_TRACER
 281         ftrace_enabled = enabled;
 282 #endif
 283 }
 284
 285 #ifdef CONFIG_FRAME_POINTER
 286 /* TODO: need to fix this for ARM */
 287 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 288 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 289 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 290 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 291 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 292 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 293 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 294 #else
 295 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 296 # define CALLER_ADDR1 0UL
 297 # define CALLER_ADDR2 0UL
 298 # define CALLER_ADDR3 0UL
 299 # define CALLER_ADDR4 0UL
 300 # define CALLER_ADDR5 0UL
 301 # define CALLER_ADDR6 0UL
 302 #endif
 303
 304 #ifdef CONFIG_IRQSOFF_TRACER
 305   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 306   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 307 #else
 308 # define time_hardirqs_on(a0, a1)               do { } while (0)
 309 # define time_hardirqs_off(a0, a1)              do { } while (0)
 310 #endif
 311
 312 #ifdef CONFIG_PREEMPT_TRACER
 313   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 314   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 315 #else
 316 # define trace_preempt_on(a0, a1)               do { } while (0)
 317 # define trace_preempt_off(a0, a1)              do { } while (0)
 318 #endif
 319
 320 #ifdef CONFIG_TRACING
 321 extern int ftrace_dump_on_oops;
 322
 323 extern void tracing_start(void);
 324 extern void tracing_stop(void);
 325 extern void ftrace_off_permanent(void);
 326
 327 extern void
 328 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
 329
 330 /**
 331  * ftrace_printk - printf formatting in the ftrace buffer
 332  * @fmt: the printf format for printing
 333  *
 334  * Note: __ftrace_printk is an internal function for ftrace_printk and
 335  *       the @ip is passed in via the ftrace_printk macro.
 336  *
 337  * This function allows a kernel developer to debug fast path sections
 338  * that printk is not appropriate for. By scattering in various
 339  * printk like tracing in the code, a developer can quickly see
 340  * where problems are occurring.
 341  *
 342  * This is intended as a debugging tool for the developer only.
 343  * Please refrain from leaving ftrace_printks scattered around in
 344  * your code.
 345  */
 346 # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
 347 extern int
 348 __ftrace_printk(unsigned long ip, const char *fmt, ...)
 349         __attribute__ ((format (printf, 2, 3)));
 350 # define ftrace_vprintk(fmt, ap) __ftrace_printk(_THIS_IP_, fmt, ap)
 351 extern int
 352 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
 353 extern void ftrace_dump(void);
 354 #else
 355 static inline void
 356 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 357 static inline int
 358 ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
 359
 360 static inline void tracing_start(void) { }
 361 static inline void tracing_stop(void) { }
 362 static inline void ftrace_off_permanent(void) { }
 363 static inline int
 364 ftrace_printk(const char *fmt, ...)
 365 {
 366         return 0;
 367 }
 368 static inline int
 369 ftrace_vprintk(const char *fmt, va_list ap)
 370 {
 371         return 0;
 372 }
 373 static inline void ftrace_dump(void) { }
 374 #endif
 375
 376 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 377 extern void ftrace_init(void);
 378 extern void ftrace_init_module(struct module *mod,
 379                                unsigned long *start, unsigned long *end);
 380 #else
 381 static inline void ftrace_init(void) { }
 382 static inline void
 383 ftrace_init_module(struct module *mod,
 384                    unsigned long *start, unsigned long *end) { }
 385 #endif
 386
 387 /*
 388  * Structure that defines an entry function trace.
 389  */
 390 struct ftrace_graph_ent {
 391         unsigned long func; /* Current function */
 392         int depth;
 393 };
 394
 395 /*
 396  * Structure that defines a return function trace.
 397  */
 398 struct ftrace_graph_ret {
 399         unsigned long func; /* Current function */
 400         unsigned long long calltime;
 401         unsigned long long rettime;
 402         /* Number of functions that overran the depth limit for current task */
 403         unsigned long overrun;
 404         int depth;
 405 };
 406
 407 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 408
 409 /*
 410  * Stack of return addresses for functions
 411  * of a thread.
 412  * Used in struct thread_info
 413  */
 414 struct ftrace_ret_stack {
 415         unsigned long ret;
 416         unsigned long func;
 417         unsigned long long calltime;
 418 };
 419
 420 /*
 421  * Primary handler of a function return.
 422  * It relays on ftrace_return_to_handler.
 423  * Defined in entry_32/64.S
 424  */
 425 extern void return_to_handler(void);
 426
 427 extern int
 428 ftrace_push_return_trace(unsigned long ret, unsigned long long time,
 429                          unsigned long func, int *depth);
 430 extern void
 431 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret);
 432
 433 /*
 434  * Sometimes we don't want to trace a function with the function
 435  * graph tracer but we want them to keep traced by the usual function
 436  * tracer if the function graph tracer is not configured.
 437  */
 438 #define __notrace_funcgraph             notrace
 439
 440 /*
 441  * We want to which function is an entrypoint of a hardirq.
 442  * That will help us to put a signal on output.
 443  */
 444 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 445
 446 /* Limits of hardirq entrypoints */
 447 extern char __irqentry_text_start[];
 448 extern char __irqentry_text_end[];
 449
 450 #define FTRACE_RETFUNC_DEPTH 50
 451 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 452 /* Type of the callback handlers for tracing function graph*/
 453 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 454 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 455
 456 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 457                                 trace_func_graph_ent_t entryfunc);
 458
 459 extern void ftrace_graph_stop(void);
 460
 461 /* The current handlers in use */
 462 extern trace_func_graph_ret_t ftrace_graph_return;
 463 extern trace_func_graph_ent_t ftrace_graph_entry;
 464
 465 extern void unregister_ftrace_graph(void);
 466
 467 extern void ftrace_graph_init_task(struct task_struct *t);
 468 extern void ftrace_graph_exit_task(struct task_struct *t);
 469
 470 static inline int task_curr_ret_stack(struct task_struct *t)
 471 {
 472         return t->curr_ret_stack;
 473 }
 474
 475 static inline void pause_graph_tracing(void)
 476 {
 477         atomic_inc(&current->tracing_graph_pause);
 478 }
 479
 480 static inline void unpause_graph_tracing(void)
 481 {
 482         atomic_dec(&current->tracing_graph_pause);
 483 }
 484 #else
 485
 486 #define __notrace_funcgraph
 487 #define __irq_entry
 488
 489 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 490 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 491
 492 static inline int task_curr_ret_stack(struct task_struct *tsk)
 493 {
 494         return -1;
 495 }
 496
 497 static inline void pause_graph_tracing(void) { }
 498 static inline void unpause_graph_tracing(void) { }
 499 #endif
 500
 501 #ifdef CONFIG_TRACING
 502 #include <linux/sched.h>
 503
 504 /* flags for current->trace */
 505 enum {
 506         TSK_TRACE_FL_TRACE_BIT  = 0,
 507         TSK_TRACE_FL_GRAPH_BIT  = 1,
 508 };
 509 enum {
 510         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 511         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 512 };
 513
 514 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 515 {
 516         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 517 }
 518
 519 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 520 {
 521         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 522 }
 523
 524 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 525 {
 526         return tsk->trace & TSK_TRACE_FL_TRACE;
 527 }
 528
 529 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 530 {
 531         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 532 }
 533
 534 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 535 {
 536         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 537 }
 538
 539 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 540 {
 541         return tsk->trace & TSK_TRACE_FL_GRAPH;
 542 }
 543
 544 #endif /* CONFIG_TRACING */
 545
 546
 547 #ifdef CONFIG_HW_BRANCH_TRACER
 548
 549 void trace_hw_branch(u64 from, u64 to);
 550 void trace_hw_branch_oops(void);
 551
 552 #else /* CONFIG_HW_BRANCH_TRACER */
 553
 554 static inline void trace_hw_branch(u64 from, u64 to) {}
 555 static inline void trace_hw_branch_oops(void) {}
 556
 557 #endif /* CONFIG_HW_BRANCH_TRACER */
 558
 559 #endif /* _LINUX_FTRACE_H */