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