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 #ifdef CONFIG_DYNAMIC_FTRACE
  99 /* asm/ftrace.h must be defined for archs supporting dynamic ftrace */
 100 #include <asm/ftrace.h>
 101
 102 enum {
 103         FTRACE_FL_FREE          = (1 << 0),
 104         FTRACE_FL_FAILED        = (1 << 1),
 105         FTRACE_FL_FILTER        = (1 << 2),
 106         FTRACE_FL_ENABLED       = (1 << 3),
 107         FTRACE_FL_NOTRACE       = (1 << 4),
 108         FTRACE_FL_CONVERTED     = (1 << 5),
 109         FTRACE_FL_FROZEN        = (1 << 6),
 110 };
 111
 112 struct dyn_ftrace {
 113         struct list_head        list;
 114         unsigned long           ip; /* address of mcount call-site */
 115         unsigned long           flags;
 116         struct dyn_arch_ftrace  arch;
 117 };
 118
 119 int ftrace_force_update(void);
 120 void ftrace_set_filter(unsigned char *buf, int len, int reset);
 121
 122 /* defined in arch */
 123 extern int ftrace_ip_converted(unsigned long ip);
 124 extern int ftrace_dyn_arch_init(void *data);
 125 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 126 extern void ftrace_caller(void);
 127 extern void ftrace_call(void);
 128 extern void mcount_call(void);
 129 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 130 extern void ftrace_graph_caller(void);
 131 extern int ftrace_enable_ftrace_graph_caller(void);
 132 extern int ftrace_disable_ftrace_graph_caller(void);
 133 #else
 134 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 135 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 136 #endif
 137
 138 /**
 139  * ftrace_make_nop - convert code into top
 140  * @mod: module structure if called by module load initialization
 141  * @rec: the mcount call site record
 142  * @addr: the address that the call site should be calling
 143  *
 144  * This is a very sensitive operation and great care needs
 145  * to be taken by the arch.  The operation should carefully
 146  * read the location, check to see if what is read is indeed
 147  * what we expect it to be, and then on success of the compare,
 148  * it should write to the location.
 149  *
 150  * The code segment at @rec->ip should be a caller to @addr
 151  *
 152  * Return must be:
 153  *  0 on success
 154  *  -EFAULT on error reading the location
 155  *  -EINVAL on a failed compare of the contents
 156  *  -EPERM  on error writing to the location
 157  * Any other value will be considered a failure.
 158  */
 159 extern int ftrace_make_nop(struct module *mod,
 160                            struct dyn_ftrace *rec, unsigned long addr);
 161
 162 /**
 163  * ftrace_make_call - convert a nop call site into a call to addr
 164  * @rec: the mcount call site record
 165  * @addr: the address that the call site should call
 166  *
 167  * This is a very sensitive operation and great care needs
 168  * to be taken by the arch.  The operation should carefully
 169  * read the location, check to see if what is read is indeed
 170  * what we expect it to be, and then on success of the compare,
 171  * it should write to the location.
 172  *
 173  * The code segment at @rec->ip should be a nop
 174  *
 175  * Return must be:
 176  *  0 on success
 177  *  -EFAULT on error reading the location
 178  *  -EINVAL on a failed compare of the contents
 179  *  -EPERM  on error writing to the location
 180  * Any other value will be considered a failure.
 181  */
 182 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 183
 184
 185 /* May be defined in arch */
 186 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 187
 188 extern int skip_trace(unsigned long ip);
 189
 190 extern void ftrace_release(void *start, unsigned long size);
 191
 192 extern void ftrace_disable_daemon(void);
 193 extern void ftrace_enable_daemon(void);
 194 #else
 195 # define skip_trace(ip)                         ({ 0; })
 196 # define ftrace_force_update()                  ({ 0; })
 197 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
 198 # define ftrace_disable_daemon()                do { } while (0)
 199 # define ftrace_enable_daemon()                 do { } while (0)
 200 static inline void ftrace_release(void *start, unsigned long size) { }
 201 #endif /* CONFIG_DYNAMIC_FTRACE */
 202
 203 /* totally disable ftrace - can not re-enable after this */
 204 void ftrace_kill(void);
 205
 206 static inline void tracer_disable(void)
 207 {
 208 #ifdef CONFIG_FUNCTION_TRACER
 209         ftrace_enabled = 0;
 210 #endif
 211 }
 212
 213 /*
 214  * Ftrace disable/restore without lock. Some synchronization mechanism
 215  * must be used to prevent ftrace_enabled to be changed between
 216  * disable/restore.
 217  */
 218 static inline int __ftrace_enabled_save(void)
 219 {
 220 #ifdef CONFIG_FUNCTION_TRACER
 221         int saved_ftrace_enabled = ftrace_enabled;
 222         ftrace_enabled = 0;
 223         return saved_ftrace_enabled;
 224 #else
 225         return 0;
 226 #endif
 227 }
 228
 229 static inline void __ftrace_enabled_restore(int enabled)
 230 {
 231 #ifdef CONFIG_FUNCTION_TRACER
 232         ftrace_enabled = enabled;
 233 #endif
 234 }
 235
 236 #ifdef CONFIG_FRAME_POINTER
 237 /* TODO: need to fix this for ARM */
 238 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 239 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 240 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 241 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 242 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 243 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 244 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 245 #else
 246 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 247 # define CALLER_ADDR1 0UL
 248 # define CALLER_ADDR2 0UL
 249 # define CALLER_ADDR3 0UL
 250 # define CALLER_ADDR4 0UL
 251 # define CALLER_ADDR5 0UL
 252 # define CALLER_ADDR6 0UL
 253 #endif
 254
 255 #ifdef CONFIG_IRQSOFF_TRACER
 256   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 257   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 258 #else
 259 # define time_hardirqs_on(a0, a1)               do { } while (0)
 260 # define time_hardirqs_off(a0, a1)              do { } while (0)
 261 #endif
 262
 263 #ifdef CONFIG_PREEMPT_TRACER
 264   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 265   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 266 #else
 267 # define trace_preempt_on(a0, a1)               do { } while (0)
 268 # define trace_preempt_off(a0, a1)              do { } while (0)
 269 #endif
 270
 271 #ifdef CONFIG_TRACING
 272 extern int ftrace_dump_on_oops;
 273
 274 extern void tracing_start(void);
 275 extern void tracing_stop(void);
 276 extern void ftrace_off_permanent(void);
 277
 278 extern void
 279 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
 280
 281 /**
 282  * ftrace_printk - printf formatting in the ftrace buffer
 283  * @fmt: the printf format for printing
 284  *
 285  * Note: __ftrace_printk is an internal function for ftrace_printk and
 286  *       the @ip is passed in via the ftrace_printk macro.
 287  *
 288  * This function allows a kernel developer to debug fast path sections
 289  * that printk is not appropriate for. By scattering in various
 290  * printk like tracing in the code, a developer can quickly see
 291  * where problems are occurring.
 292  *
 293  * This is intended as a debugging tool for the developer only.
 294  * Please refrain from leaving ftrace_printks scattered around in
 295  * your code.
 296  */
 297 # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
 298 extern int
 299 __ftrace_printk(unsigned long ip, const char *fmt, ...)
 300         __attribute__ ((format (printf, 2, 3)));
 301 extern void ftrace_dump(void);
 302 #else
 303 static inline void
 304 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 305 static inline int
 306 ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
 307
 308 static inline void tracing_start(void) { }
 309 static inline void tracing_stop(void) { }
 310 static inline void ftrace_off_permanent(void) { }
 311 static inline int
 312 ftrace_printk(const char *fmt, ...)
 313 {
 314         return 0;
 315 }
 316 static inline void ftrace_dump(void) { }
 317 #endif
 318
 319 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 320 extern void ftrace_init(void);
 321 extern void ftrace_init_module(struct module *mod,
 322                                unsigned long *start, unsigned long *end);
 323 #else
 324 static inline void ftrace_init(void) { }
 325 static inline void
 326 ftrace_init_module(struct module *mod,
 327                    unsigned long *start, unsigned long *end) { }
 328 #endif
 329
 330 enum {
 331         POWER_NONE = 0,
 332         POWER_CSTATE = 1,
 333         POWER_PSTATE = 2,
 334 };
 335
 336 struct power_trace {
 337 #ifdef CONFIG_POWER_TRACER
 338         ktime_t                 stamp;
 339         ktime_t                 end;
 340         int                     type;
 341         int                     state;
 342 #endif
 343 };
 344
 345 #ifdef CONFIG_POWER_TRACER
 346 extern void trace_power_start(struct power_trace *it, unsigned int type,
 347                                         unsigned int state);
 348 extern void trace_power_mark(struct power_trace *it, unsigned int type,
 349                                         unsigned int state);
 350 extern void trace_power_end(struct power_trace *it);
 351 #else
 352 static inline void trace_power_start(struct power_trace *it, unsigned int type,
 353                                         unsigned int state) { }
 354 static inline void trace_power_mark(struct power_trace *it, unsigned int type,
 355                                         unsigned int state) { }
 356 static inline void trace_power_end(struct power_trace *it) { }
 357 #endif
 358
 359
 360 /*
 361  * Structure that defines an entry function trace.
 362  */
 363 struct ftrace_graph_ent {
 364         unsigned long func; /* Current function */
 365         int depth;
 366 };
 367
 368 /*
 369  * Structure that defines a return function trace.
 370  */
 371 struct ftrace_graph_ret {
 372         unsigned long func; /* Current function */
 373         unsigned long long calltime;
 374         unsigned long long rettime;
 375         /* Number of functions that overran the depth limit for current task */
 376         unsigned long overrun;
 377         int depth;
 378 };
 379
 380 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 381
 382 /*
 383  * Stack of return addresses for functions
 384  * of a thread.
 385  * Used in struct thread_info
 386  */
 387 struct ftrace_ret_stack {
 388         unsigned long ret;
 389         unsigned long func;
 390         unsigned long long calltime;
 391 };
 392
 393 /*
 394  * Primary handler of a function return.
 395  * It relays on ftrace_return_to_handler.
 396  * Defined in entry_32/64.S
 397  */
 398 extern void return_to_handler(void);
 399
 400 extern int
 401 ftrace_push_return_trace(unsigned long ret, unsigned long long time,
 402                          unsigned long func, int *depth);
 403 extern void
 404 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret);
 405
 406 /*
 407  * Sometimes we don't want to trace a function with the function
 408  * graph tracer but we want them to keep traced by the usual function
 409  * tracer if the function graph tracer is not configured.
 410  */
 411 #define __notrace_funcgraph             notrace
 412
 413 /*
 414  * We want to which function is an entrypoint of a hardirq.
 415  * That will help us to put a signal on output.
 416  */
 417 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 418
 419 /* Limits of hardirq entrypoints */
 420 extern char __irqentry_text_start[];
 421 extern char __irqentry_text_end[];
 422
 423 #define FTRACE_RETFUNC_DEPTH 50
 424 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 425 /* Type of the callback handlers for tracing function graph*/
 426 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 427 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 428
 429 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 430                                 trace_func_graph_ent_t entryfunc);
 431
 432 extern void ftrace_graph_stop(void);
 433
 434 /* The current handlers in use */
 435 extern trace_func_graph_ret_t ftrace_graph_return;
 436 extern trace_func_graph_ent_t ftrace_graph_entry;
 437
 438 extern void unregister_ftrace_graph(void);
 439
 440 extern void ftrace_graph_init_task(struct task_struct *t);
 441 extern void ftrace_graph_exit_task(struct task_struct *t);
 442
 443 static inline int task_curr_ret_stack(struct task_struct *t)
 444 {
 445         return t->curr_ret_stack;
 446 }
 447
 448 static inline void pause_graph_tracing(void)
 449 {
 450         atomic_inc(&current->tracing_graph_pause);
 451 }
 452
 453 static inline void unpause_graph_tracing(void)
 454 {
 455         atomic_dec(&current->tracing_graph_pause);
 456 }
 457 #else
 458
 459 #define __notrace_funcgraph
 460 #define __irq_entry
 461
 462 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 463 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 464
 465 static inline int task_curr_ret_stack(struct task_struct *tsk)
 466 {
 467         return -1;
 468 }
 469
 470 static inline void pause_graph_tracing(void) { }
 471 static inline void unpause_graph_tracing(void) { }
 472 #endif
 473
 474 #ifdef CONFIG_TRACING
 475 #include <linux/sched.h>
 476
 477 /* flags for current->trace */
 478 enum {
 479         TSK_TRACE_FL_TRACE_BIT  = 0,
 480         TSK_TRACE_FL_GRAPH_BIT  = 1,
 481 };
 482 enum {
 483         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 484         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 485 };
 486
 487 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 488 {
 489         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 490 }
 491
 492 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 493 {
 494         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 495 }
 496
 497 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 498 {
 499         return tsk->trace & TSK_TRACE_FL_TRACE;
 500 }
 501
 502 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 503 {
 504         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 505 }
 506
 507 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 508 {
 509         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 510 }
 511
 512 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 513 {
 514         return tsk->trace & TSK_TRACE_FL_GRAPH;
 515 }
 516
 517 #endif /* CONFIG_TRACING */
 518
 519 #endif /* _LINUX_FTRACE_H */