include/linux/ftrace.h

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