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