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 # define register_ftrace_function(ops) do { } while (0)
  86 # define unregister_ftrace_function(ops) do { } while (0)
  87 # define clear_ftrace_function(ops) do { } while (0)
  88 static inline void ftrace_kill(void) { }
  89 static inline void ftrace_stop(void) { }
  90 static inline void ftrace_start(void) { }
  91 #endif /* CONFIG_FUNCTION_TRACER */
  92
  93 #ifdef CONFIG_STACK_TRACER
  94 extern int stack_tracer_enabled;
  95 int
  96 stack_trace_sysctl(struct ctl_table *table, int write,
  97                    void __user *buffer, size_t *lenp,
  98                    loff_t *ppos);
  99 #endif
 100
 101 struct ftrace_func_command {
 102         struct list_head        list;
 103         char                    *name;
 104         int                     (*func)(char *func, char *cmd,
 105                                         char *params, int enable);
 106 };
 107
 108 #ifdef CONFIG_DYNAMIC_FTRACE
 109
 110 int ftrace_arch_code_modify_prepare(void);
 111 int ftrace_arch_code_modify_post_process(void);
 112
 113 struct seq_file;
 114
 115 struct ftrace_probe_ops {
 116         void                    (*func)(unsigned long ip,
 117                                         unsigned long parent_ip,
 118                                         void **data);
 119         int                     (*callback)(unsigned long ip, void **data);
 120         void                    (*free)(void **data);
 121         int                     (*print)(struct seq_file *m,
 122                                          unsigned long ip,
 123                                          struct ftrace_probe_ops *ops,
 124                                          void *data);
 125 };
 126
 127 extern int
 128 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 129                               void *data);
 130 extern void
 131 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 132                                 void *data);
 133 extern void
 134 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
 135 extern void unregister_ftrace_function_probe_all(char *glob);
 136
 137 extern int ftrace_text_reserved(void *start, void *end);
 138
 139 enum {
 140         FTRACE_FL_FREE          = (1 << 0),
 141         FTRACE_FL_FAILED        = (1 << 1),
 142         FTRACE_FL_FILTER        = (1 << 2),
 143         FTRACE_FL_ENABLED       = (1 << 3),
 144         FTRACE_FL_NOTRACE       = (1 << 4),
 145         FTRACE_FL_CONVERTED     = (1 << 5),
 146 };
 147
 148 struct dyn_ftrace {
 149         union {
 150                 unsigned long           ip; /* address of mcount call-site */
 151                 struct dyn_ftrace       *freelist;
 152         };
 153         union {
 154                 unsigned long           flags;
 155                 struct dyn_ftrace       *newlist;
 156         };
 157         struct dyn_arch_ftrace          arch;
 158 };
 159
 160 int ftrace_force_update(void);
 161 void ftrace_set_filter(unsigned char *buf, int len, int reset);
 162
 163 int register_ftrace_command(struct ftrace_func_command *cmd);
 164 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 165
 166 /* defined in arch */
 167 extern int ftrace_ip_converted(unsigned long ip);
 168 extern int ftrace_dyn_arch_init(void *data);
 169 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 170 extern void ftrace_caller(void);
 171 extern void ftrace_call(void);
 172 extern void mcount_call(void);
 173
 174 #ifndef FTRACE_ADDR
 175 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 176 #endif
 177 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 178 extern void ftrace_graph_caller(void);
 179 extern int ftrace_enable_ftrace_graph_caller(void);
 180 extern int ftrace_disable_ftrace_graph_caller(void);
 181 #else
 182 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 183 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 184 #endif
 185
 186 /**
 187  * ftrace_make_nop - convert code into nop
 188  * @mod: module structure if called by module load initialization
 189  * @rec: the mcount call site record
 190  * @addr: the address that the call site should be calling
 191  *
 192  * This is a very sensitive operation and great care needs
 193  * to be taken by the arch.  The operation should carefully
 194  * read the location, check to see if what is read is indeed
 195  * what we expect it to be, and then on success of the compare,
 196  * it should write to the location.
 197  *
 198  * The code segment at @rec->ip should be a caller to @addr
 199  *
 200  * Return must be:
 201  *  0 on success
 202  *  -EFAULT on error reading the location
 203  *  -EINVAL on a failed compare of the contents
 204  *  -EPERM  on error writing to the location
 205  * Any other value will be considered a failure.
 206  */
 207 extern int ftrace_make_nop(struct module *mod,
 208                            struct dyn_ftrace *rec, unsigned long addr);
 209
 210 /**
 211  * ftrace_make_call - convert a nop call site into a call to addr
 212  * @rec: the mcount call site record
 213  * @addr: the address that the call site should call
 214  *
 215  * This is a very sensitive operation and great care needs
 216  * to be taken by the arch.  The operation should carefully
 217  * read the location, check to see if what is read is indeed
 218  * what we expect it to be, and then on success of the compare,
 219  * it should write to the location.
 220  *
 221  * The code segment at @rec->ip should be a nop
 222  *
 223  * Return must be:
 224  *  0 on success
 225  *  -EFAULT on error reading the location
 226  *  -EINVAL on a failed compare of the contents
 227  *  -EPERM  on error writing to the location
 228  * Any other value will be considered a failure.
 229  */
 230 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 231
 232 /* May be defined in arch */
 233 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 234
 235 extern int skip_trace(unsigned long ip);
 236
 237 extern void ftrace_disable_daemon(void);
 238 extern void ftrace_enable_daemon(void);
 239 #else
 240 # define skip_trace(ip)                         ({ 0; })
 241 # define ftrace_force_update()                  ({ 0; })
 242 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
 243 # define ftrace_disable_daemon()                do { } while (0)
 244 # define ftrace_enable_daemon()                 do { } while (0)
 245 static inline void ftrace_release_mod(struct module *mod) {}
 246 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
 247 {
 248         return -EINVAL;
 249 }
 250 static inline int unregister_ftrace_command(char *cmd_name)
 251 {
 252         return -EINVAL;
 253 }
 254 static inline int ftrace_text_reserved(void *start, void *end)
 255 {
 256         return 0;
 257 }
 258 #endif /* CONFIG_DYNAMIC_FTRACE */
 259
 260 /* totally disable ftrace - can not re-enable after this */
 261 void ftrace_kill(void);
 262
 263 static inline void tracer_disable(void)
 264 {
 265 #ifdef CONFIG_FUNCTION_TRACER
 266         ftrace_enabled = 0;
 267 #endif
 268 }
 269
 270 /*
 271  * Ftrace disable/restore without lock. Some synchronization mechanism
 272  * must be used to prevent ftrace_enabled to be changed between
 273  * disable/restore.
 274  */
 275 static inline int __ftrace_enabled_save(void)
 276 {
 277 #ifdef CONFIG_FUNCTION_TRACER
 278         int saved_ftrace_enabled = ftrace_enabled;
 279         ftrace_enabled = 0;
 280         return saved_ftrace_enabled;
 281 #else
 282         return 0;
 283 #endif
 284 }
 285
 286 static inline void __ftrace_enabled_restore(int enabled)
 287 {
 288 #ifdef CONFIG_FUNCTION_TRACER
 289         ftrace_enabled = enabled;
 290 #endif
 291 }
 292
 293 #ifndef HAVE_ARCH_CALLER_ADDR
 294 # ifdef CONFIG_FRAME_POINTER
 295 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 296 #  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 297 #  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 298 #  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 299 #  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 300 #  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 301 #  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 302 # else
 303 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 304 #  define CALLER_ADDR1 0UL
 305 #  define CALLER_ADDR2 0UL
 306 #  define CALLER_ADDR3 0UL
 307 #  define CALLER_ADDR4 0UL
 308 #  define CALLER_ADDR5 0UL
 309 #  define CALLER_ADDR6 0UL
 310 # endif
 311 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
 312
 313 #ifdef CONFIG_IRQSOFF_TRACER
 314   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 315   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 316 #else
 317 # define time_hardirqs_on(a0, a1)               do { } while (0)
 318 # define time_hardirqs_off(a0, a1)              do { } while (0)
 319 #endif
 320
 321 #ifdef CONFIG_PREEMPT_TRACER
 322   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 323   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 324 #else
 325 # define trace_preempt_on(a0, a1)               do { } while (0)
 326 # define trace_preempt_off(a0, a1)              do { } while (0)
 327 #endif
 328
 329 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 330 extern void ftrace_init(void);
 331 #else
 332 static inline void ftrace_init(void) { }
 333 #endif
 334
 335 /*
 336  * Structure that defines an entry function trace.
 337  */
 338 struct ftrace_graph_ent {
 339         unsigned long func; /* Current function */
 340         int depth;
 341 };
 342
 343 /*
 344  * Structure that defines a return function trace.
 345  */
 346 struct ftrace_graph_ret {
 347         unsigned long func; /* Current function */
 348         unsigned long long calltime;
 349         unsigned long long rettime;
 350         /* Number of functions that overran the depth limit for current task */
 351         unsigned long overrun;
 352         int depth;
 353 };
 354
 355 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 356
 357 /* for init task */
 358 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
 359
 360 /*
 361  * Stack of return addresses for functions
 362  * of a thread.
 363  * Used in struct thread_info
 364  */
 365 struct ftrace_ret_stack {
 366         unsigned long ret;
 367         unsigned long func;
 368         unsigned long long calltime;
 369         unsigned long long subtime;
 370         unsigned long fp;
 371 };
 372
 373 /*
 374  * Primary handler of a function return.
 375  * It relays on ftrace_return_to_handler.
 376  * Defined in entry_32/64.S
 377  */
 378 extern void return_to_handler(void);
 379
 380 extern int
 381 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
 382                          unsigned long frame_pointer);
 383
 384 /*
 385  * Sometimes we don't want to trace a function with the function
 386  * graph tracer but we want them to keep traced by the usual function
 387  * tracer if the function graph tracer is not configured.
 388  */
 389 #define __notrace_funcgraph             notrace
 390
 391 /*
 392  * We want to which function is an entrypoint of a hardirq.
 393  * That will help us to put a signal on output.
 394  */
 395 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 396
 397 /* Limits of hardirq entrypoints */
 398 extern char __irqentry_text_start[];
 399 extern char __irqentry_text_end[];
 400
 401 #define FTRACE_RETFUNC_DEPTH 50
 402 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 403 /* Type of the callback handlers for tracing function graph*/
 404 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 405 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 406
 407 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 408                                 trace_func_graph_ent_t entryfunc);
 409
 410 extern void ftrace_graph_stop(void);
 411
 412 /* The current handlers in use */
 413 extern trace_func_graph_ret_t ftrace_graph_return;
 414 extern trace_func_graph_ent_t ftrace_graph_entry;
 415
 416 extern void unregister_ftrace_graph(void);
 417
 418 extern void ftrace_graph_init_task(struct task_struct *t);
 419 extern void ftrace_graph_exit_task(struct task_struct *t);
 420
 421 static inline int task_curr_ret_stack(struct task_struct *t)
 422 {
 423         return t->curr_ret_stack;
 424 }
 425
 426 static inline void pause_graph_tracing(void)
 427 {
 428         atomic_inc(&current->tracing_graph_pause);
 429 }
 430
 431 static inline void unpause_graph_tracing(void)
 432 {
 433         atomic_dec(&current->tracing_graph_pause);
 434 }
 435 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 436
 437 #define __notrace_funcgraph
 438 #define __irq_entry
 439 #define INIT_FTRACE_GRAPH
 440
 441 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 442 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 443
 444 static inline int task_curr_ret_stack(struct task_struct *tsk)
 445 {
 446         return -1;
 447 }
 448
 449 static inline void pause_graph_tracing(void) { }
 450 static inline void unpause_graph_tracing(void) { }
 451 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 452
 453 #ifdef CONFIG_TRACING
 454
 455 /* flags for current->trace */
 456 enum {
 457         TSK_TRACE_FL_TRACE_BIT  = 0,
 458         TSK_TRACE_FL_GRAPH_BIT  = 1,
 459 };
 460 enum {
 461         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 462         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 463 };
 464
 465 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 466 {
 467         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 468 }
 469
 470 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 471 {
 472         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 473 }
 474
 475 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 476 {
 477         return tsk->trace & TSK_TRACE_FL_TRACE;
 478 }
 479
 480 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 481 {
 482         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 483 }
 484
 485 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 486 {
 487         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 488 }
 489
 490 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 491 {
 492         return tsk->trace & TSK_TRACE_FL_GRAPH;
 493 }
 494
 495 extern int ftrace_dump_on_oops;
 496
 497 #ifdef CONFIG_PREEMPT
 498 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
 499 #endif
 500
 501 #endif /* CONFIG_TRACING */
 502
 503 #ifndef INIT_TRACE_RECURSION
 504 #define INIT_TRACE_RECURSION
 505 #endif
 506
 507 #ifdef CONFIG_HW_BRANCH_TRACER
 508
 509 void trace_hw_branch(u64 from, u64 to);
 510 void trace_hw_branch_oops(void);
 511
 512 #else /* CONFIG_HW_BRANCH_TRACER */
 513
 514 static inline void trace_hw_branch(u64 from, u64 to) {}
 515 static inline void trace_hw_branch_oops(void) {}
 516
 517 #endif /* CONFIG_HW_BRANCH_TRACER */
 518
 519 #ifdef CONFIG_FTRACE_SYSCALLS
 520
 521 unsigned long arch_syscall_addr(int nr);
 522
 523 #endif /* CONFIG_FTRACE_SYSCALLS */
 524
 525 #endif /* _LINUX_FTRACE_H */