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 int ftrace_arch_code_modify_prepare(void);
 103 int ftrace_arch_code_modify_post_process(void);
 104
 105 enum {
 106         FTRACE_FL_FREE          = (1 << 0),
 107         FTRACE_FL_FAILED        = (1 << 1),
 108         FTRACE_FL_FILTER        = (1 << 2),
 109         FTRACE_FL_ENABLED       = (1 << 3),
 110         FTRACE_FL_NOTRACE       = (1 << 4),
 111         FTRACE_FL_CONVERTED     = (1 << 5),
 112         FTRACE_FL_FROZEN        = (1 << 6),
 113 };
 114
 115 struct dyn_ftrace {
 116         struct list_head        list;
 117         unsigned long           ip; /* address of mcount call-site */
 118         unsigned long           flags;
 119         struct dyn_arch_ftrace  arch;
 120 };
 121
 122 int ftrace_force_update(void);
 123 void ftrace_set_filter(unsigned char *buf, int len, int reset);
 124
 125 /* defined in arch */
 126 extern int ftrace_ip_converted(unsigned long ip);
 127 extern int ftrace_dyn_arch_init(void *data);
 128 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 129 extern void ftrace_caller(void);
 130 extern void ftrace_call(void);
 131 extern void mcount_call(void);
 132 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 133 extern void ftrace_graph_caller(void);
 134 extern int ftrace_enable_ftrace_graph_caller(void);
 135 extern int ftrace_disable_ftrace_graph_caller(void);
 136 #else
 137 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 138 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 139 #endif
 140
 141 /**
 142  * ftrace_make_nop - convert code into top
 143  * @mod: module structure if called by module load initialization
 144  * @rec: the mcount call site record
 145  * @addr: the address that the call site should be calling
 146  *
 147  * This is a very sensitive operation and great care needs
 148  * to be taken by the arch.  The operation should carefully
 149  * read the location, check to see if what is read is indeed
 150  * what we expect it to be, and then on success of the compare,
 151  * it should write to the location.
 152  *
 153  * The code segment at @rec->ip should be a caller to @addr
 154  *
 155  * Return must be:
 156  *  0 on success
 157  *  -EFAULT on error reading the location
 158  *  -EINVAL on a failed compare of the contents
 159  *  -EPERM  on error writing to the location
 160  * Any other value will be considered a failure.
 161  */
 162 extern int ftrace_make_nop(struct module *mod,
 163                            struct dyn_ftrace *rec, unsigned long addr);
 164
 165 /**
 166  * ftrace_make_call - convert a nop call site into a call to addr
 167  * @rec: the mcount call site record
 168  * @addr: the address that the call site should call
 169  *
 170  * This is a very sensitive operation and great care needs
 171  * to be taken by the arch.  The operation should carefully
 172  * read the location, check to see if what is read is indeed
 173  * what we expect it to be, and then on success of the compare,
 174  * it should write to the location.
 175  *
 176  * The code segment at @rec->ip should be a nop
 177  *
 178  * Return must be:
 179  *  0 on success
 180  *  -EFAULT on error reading the location
 181  *  -EINVAL on a failed compare of the contents
 182  *  -EPERM  on error writing to the location
 183  * Any other value will be considered a failure.
 184  */
 185 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 186
 187
 188 /* May be defined in arch */
 189 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 190
 191 extern int skip_trace(unsigned long ip);
 192
 193 extern void ftrace_release(void *start, unsigned long size);
 194
 195 extern void ftrace_disable_daemon(void);
 196 extern void ftrace_enable_daemon(void);
 197 #else
 198 # define skip_trace(ip)                         ({ 0; })
 199 # define ftrace_force_update()                  ({ 0; })
 200 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
 201 # define ftrace_disable_daemon()                do { } while (0)
 202 # define ftrace_enable_daemon()                 do { } while (0)
 203 static inline void ftrace_release(void *start, unsigned long size) { }
 204 #endif /* CONFIG_DYNAMIC_FTRACE */
 205
 206 /* totally disable ftrace - can not re-enable after this */
 207 void ftrace_kill(void);
 208
 209 static inline void tracer_disable(void)
 210 {
 211 #ifdef CONFIG_FUNCTION_TRACER
 212         ftrace_enabled = 0;
 213 #endif
 214 }
 215
 216 /*
 217  * Ftrace disable/restore without lock. Some synchronization mechanism
 218  * must be used to prevent ftrace_enabled to be changed between
 219  * disable/restore.
 220  */
 221 static inline int __ftrace_enabled_save(void)
 222 {
 223 #ifdef CONFIG_FUNCTION_TRACER
 224         int saved_ftrace_enabled = ftrace_enabled;
 225         ftrace_enabled = 0;
 226         return saved_ftrace_enabled;
 227 #else
 228         return 0;
 229 #endif
 230 }
 231
 232 static inline void __ftrace_enabled_restore(int enabled)
 233 {
 234 #ifdef CONFIG_FUNCTION_TRACER
 235         ftrace_enabled = enabled;
 236 #endif
 237 }
 238
 239 #ifdef CONFIG_FRAME_POINTER
 240 /* TODO: need to fix this for ARM */
 241 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 242 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 243 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 244 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 245 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 246 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 247 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 248 #else
 249 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 250 # define CALLER_ADDR1 0UL
 251 # define CALLER_ADDR2 0UL
 252 # define CALLER_ADDR3 0UL
 253 # define CALLER_ADDR4 0UL
 254 # define CALLER_ADDR5 0UL
 255 # define CALLER_ADDR6 0UL
 256 #endif
 257
 258 #ifdef CONFIG_IRQSOFF_TRACER
 259   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 260   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 261 #else
 262 # define time_hardirqs_on(a0, a1)               do { } while (0)
 263 # define time_hardirqs_off(a0, a1)              do { } while (0)
 264 #endif
 265
 266 #ifdef CONFIG_PREEMPT_TRACER
 267   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 268   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 269 #else
 270 # define trace_preempt_on(a0, a1)               do { } while (0)
 271 # define trace_preempt_off(a0, a1)              do { } while (0)
 272 #endif
 273
 274 #ifdef CONFIG_TRACING
 275 extern int ftrace_dump_on_oops;
 276
 277 extern void tracing_start(void);
 278 extern void tracing_stop(void);
 279 extern void ftrace_off_permanent(void);
 280
 281 extern void
 282 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
 283
 284 /**
 285  * ftrace_printk - printf formatting in the ftrace buffer
 286  * @fmt: the printf format for printing
 287  *
 288  * Note: __ftrace_printk is an internal function for ftrace_printk and
 289  *       the @ip is passed in via the ftrace_printk macro.
 290  *
 291  * This function allows a kernel developer to debug fast path sections
 292  * that printk is not appropriate for. By scattering in various
 293  * printk like tracing in the code, a developer can quickly see
 294  * where problems are occurring.
 295  *
 296  * This is intended as a debugging tool for the developer only.
 297  * Please refrain from leaving ftrace_printks scattered around in
 298  * your code.
 299  */
 300 # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
 301 extern int
 302 __ftrace_printk(unsigned long ip, const char *fmt, ...)
 303         __attribute__ ((format (printf, 2, 3)));
 304 extern void ftrace_dump(void);
 305 #else
 306 static inline void
 307 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 308 static inline int
 309 ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
 310
 311 static inline void tracing_start(void) { }
 312 static inline void tracing_stop(void) { }
 313 static inline void ftrace_off_permanent(void) { }
 314 static inline int
 315 ftrace_printk(const char *fmt, ...)
 316 {
 317         return 0;
 318 }
 319 static inline void ftrace_dump(void) { }
 320 #endif
 321
 322 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 323 extern void ftrace_init(void);
 324 extern void ftrace_init_module(struct module *mod,
 325                                unsigned long *start, unsigned long *end);
 326 #else
 327 static inline void ftrace_init(void) { }
 328 static inline void
 329 ftrace_init_module(struct module *mod,
 330                    unsigned long *start, unsigned long *end) { }
 331 #endif
 332
 333 enum {
 334         POWER_NONE = 0,
 335         POWER_CSTATE = 1,
 336         POWER_PSTATE = 2,
 337 };
 338
 339 struct power_trace {
 340 #ifdef CONFIG_POWER_TRACER
 341         ktime_t                 stamp;
 342         ktime_t                 end;
 343         int                     type;
 344         int                     state;
 345 #endif
 346 };
 347
 348 #ifdef CONFIG_POWER_TRACER
 349 extern void trace_power_start(struct power_trace *it, unsigned int type,
 350                                         unsigned int state);
 351 extern void trace_power_mark(struct power_trace *it, unsigned int type,
 352                                         unsigned int state);
 353 extern void trace_power_end(struct power_trace *it);
 354 #else
 355 static inline void trace_power_start(struct power_trace *it, unsigned int type,
 356                                         unsigned int state) { }
 357 static inline void trace_power_mark(struct power_trace *it, unsigned int type,
 358                                         unsigned int state) { }
 359 static inline void trace_power_end(struct power_trace *it) { }
 360 #endif
 361
 362
 363 /*
 364  * Structure that defines an entry function trace.
 365  */
 366 struct ftrace_graph_ent {
 367         unsigned long func; /* Current function */
 368         int depth;
 369 };
 370
 371 /*
 372  * Structure that defines a return function trace.
 373  */
 374 struct ftrace_graph_ret {
 375         unsigned long func; /* Current function */
 376         unsigned long long calltime;
 377         unsigned long long rettime;
 378         /* Number of functions that overran the depth limit for current task */
 379         unsigned long overrun;
 380         int depth;
 381 };
 382
 383 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 384
 385 /*
 386  * Sometimes we don't want to trace a function with the function
 387  * graph tracer but we want them to keep traced by the usual function
 388  * tracer if the function graph tracer is not configured.
 389  */
 390 #define __notrace_funcgraph             notrace
 391
 392 /*
 393  * We want to which function is an entrypoint of a hardirq.
 394  * That will help us to put a signal on output.
 395  */
 396 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 397
 398 /* Limits of hardirq entrypoints */
 399 extern char __irqentry_text_start[];
 400 extern char __irqentry_text_end[];
 401
 402 #define FTRACE_RETFUNC_DEPTH 50
 403 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 404 /* Type of the callback handlers for tracing function graph*/
 405 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 406 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 407
 408 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 409                                 trace_func_graph_ent_t entryfunc);
 410
 411 extern void ftrace_graph_stop(void);
 412
 413 /* The current handlers in use */
 414 extern trace_func_graph_ret_t ftrace_graph_return;
 415 extern trace_func_graph_ent_t ftrace_graph_entry;
 416
 417 extern void unregister_ftrace_graph(void);
 418
 419 extern void ftrace_graph_init_task(struct task_struct *t);
 420 extern void ftrace_graph_exit_task(struct task_struct *t);
 421
 422 static inline int task_curr_ret_stack(struct task_struct *t)
 423 {
 424         return t->curr_ret_stack;
 425 }
 426
 427 static inline void pause_graph_tracing(void)
 428 {
 429         atomic_inc(&current->tracing_graph_pause);
 430 }
 431
 432 static inline void unpause_graph_tracing(void)
 433 {
 434         atomic_dec(&current->tracing_graph_pause);
 435 }
 436 #else
 437
 438 #define __notrace_funcgraph
 439 #define __irq_entry
 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
 452
 453 #ifdef CONFIG_TRACING
 454 #include <linux/sched.h>
 455
 456 /* flags for current->trace */
 457 enum {
 458         TSK_TRACE_FL_TRACE_BIT  = 0,
 459         TSK_TRACE_FL_GRAPH_BIT  = 1,
 460 };
 461 enum {
 462         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 463         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 464 };
 465
 466 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 467 {
 468         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 469 }
 470
 471 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 472 {
 473         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 474 }
 475
 476 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 477 {
 478         return tsk->trace & TSK_TRACE_FL_TRACE;
 479 }
 480
 481 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 482 {
 483         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 484 }
 485
 486 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 487 {
 488         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 489 }
 490
 491 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 492 {
 493         return tsk->trace & TSK_TRACE_FL_GRAPH;
 494 }
 495
 496 #endif /* CONFIG_TRACING */
 497
 498 #endif /* _LINUX_FTRACE_H */