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