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                      struct file *filp, 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                    struct file *file, 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         unsigned long           ip; /* address of mcount call-site */
 149         unsigned long           flags;
 150         struct dyn_arch_ftrace  arch;
 151 };
 152
 153 int ftrace_force_update(void);
 154 void ftrace_set_filter(unsigned char *buf, int len, int reset);
 155
 156 int register_ftrace_command(struct ftrace_func_command *cmd);
 157 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 158
 159 /* defined in arch */
 160 extern int ftrace_ip_converted(unsigned long ip);
 161 extern int ftrace_dyn_arch_init(void *data);
 162 extern int ftrace_update_ftrace_func(ftrace_func_t func);
 163 extern void ftrace_caller(void);
 164 extern void ftrace_call(void);
 165 extern void mcount_call(void);
 166
 167 #ifndef FTRACE_ADDR
 168 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
 169 #endif
 170 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 171 extern void ftrace_graph_caller(void);
 172 extern int ftrace_enable_ftrace_graph_caller(void);
 173 extern int ftrace_disable_ftrace_graph_caller(void);
 174 #else
 175 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
 176 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
 177 #endif
 178
 179 /**
 180  * ftrace_make_nop - convert code into nop
 181  * @mod: module structure if called by module load initialization
 182  * @rec: the mcount call site record
 183  * @addr: the address that the call site should be calling
 184  *
 185  * This is a very sensitive operation and great care needs
 186  * to be taken by the arch.  The operation should carefully
 187  * read the location, check to see if what is read is indeed
 188  * what we expect it to be, and then on success of the compare,
 189  * it should write to the location.
 190  *
 191  * The code segment at @rec->ip should be a caller to @addr
 192  *
 193  * Return must be:
 194  *  0 on success
 195  *  -EFAULT on error reading the location
 196  *  -EINVAL on a failed compare of the contents
 197  *  -EPERM  on error writing to the location
 198  * Any other value will be considered a failure.
 199  */
 200 extern int ftrace_make_nop(struct module *mod,
 201                            struct dyn_ftrace *rec, unsigned long addr);
 202
 203 /**
 204  * ftrace_make_call - convert a nop call site into a call to addr
 205  * @rec: the mcount call site record
 206  * @addr: the address that the call site should call
 207  *
 208  * This is a very sensitive operation and great care needs
 209  * to be taken by the arch.  The operation should carefully
 210  * read the location, check to see if what is read is indeed
 211  * what we expect it to be, and then on success of the compare,
 212  * it should write to the location.
 213  *
 214  * The code segment at @rec->ip should be a nop
 215  *
 216  * Return must be:
 217  *  0 on success
 218  *  -EFAULT on error reading the location
 219  *  -EINVAL on a failed compare of the contents
 220  *  -EPERM  on error writing to the location
 221  * Any other value will be considered a failure.
 222  */
 223 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
 224
 225 /* May be defined in arch */
 226 extern int ftrace_arch_read_dyn_info(char *buf, int size);
 227
 228 extern int skip_trace(unsigned long ip);
 229
 230 extern void ftrace_release(void *start, unsigned long size);
 231
 232 extern void ftrace_disable_daemon(void);
 233 extern void ftrace_enable_daemon(void);
 234 #else
 235 # define skip_trace(ip)                         ({ 0; })
 236 # define ftrace_force_update()                  ({ 0; })
 237 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
 238 # define ftrace_disable_daemon()                do { } while (0)
 239 # define ftrace_enable_daemon()                 do { } while (0)
 240 static inline void ftrace_release(void *start, unsigned long size) { }
 241 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
 242 {
 243         return -EINVAL;
 244 }
 245 static inline int unregister_ftrace_command(char *cmd_name)
 246 {
 247         return -EINVAL;
 248 }
 249 #endif /* CONFIG_DYNAMIC_FTRACE */
 250
 251 /* totally disable ftrace - can not re-enable after this */
 252 void ftrace_kill(void);
 253
 254 static inline void tracer_disable(void)
 255 {
 256 #ifdef CONFIG_FUNCTION_TRACER
 257         ftrace_enabled = 0;
 258 #endif
 259 }
 260
 261 /*
 262  * Ftrace disable/restore without lock. Some synchronization mechanism
 263  * must be used to prevent ftrace_enabled to be changed between
 264  * disable/restore.
 265  */
 266 static inline int __ftrace_enabled_save(void)
 267 {
 268 #ifdef CONFIG_FUNCTION_TRACER
 269         int saved_ftrace_enabled = ftrace_enabled;
 270         ftrace_enabled = 0;
 271         return saved_ftrace_enabled;
 272 #else
 273         return 0;
 274 #endif
 275 }
 276
 277 static inline void __ftrace_enabled_restore(int enabled)
 278 {
 279 #ifdef CONFIG_FUNCTION_TRACER
 280         ftrace_enabled = enabled;
 281 #endif
 282 }
 283
 284 #ifndef HAVE_ARCH_CALLER_ADDR
 285 # ifdef CONFIG_FRAME_POINTER
 286 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 287 #  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 288 #  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 289 #  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 290 #  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 291 #  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 292 #  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 293 # else
 294 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 295 #  define CALLER_ADDR1 0UL
 296 #  define CALLER_ADDR2 0UL
 297 #  define CALLER_ADDR3 0UL
 298 #  define CALLER_ADDR4 0UL
 299 #  define CALLER_ADDR5 0UL
 300 #  define CALLER_ADDR6 0UL
 301 # endif
 302 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
 303
 304 #ifdef CONFIG_IRQSOFF_TRACER
 305   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 306   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 307 #else
 308 # define time_hardirqs_on(a0, a1)               do { } while (0)
 309 # define time_hardirqs_off(a0, a1)              do { } while (0)
 310 #endif
 311
 312 #ifdef CONFIG_PREEMPT_TRACER
 313   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 314   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 315 #else
 316 # define trace_preempt_on(a0, a1)               do { } while (0)
 317 # define trace_preempt_off(a0, a1)              do { } while (0)
 318 #endif
 319
 320 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 321 extern void ftrace_init(void);
 322 extern void ftrace_init_module(struct module *mod,
 323                                unsigned long *start, unsigned long *end);
 324 #else
 325 static inline void ftrace_init(void) { }
 326 static inline void
 327 ftrace_init_module(struct module *mod,
 328                    unsigned long *start, unsigned long *end) { }
 329 #endif
 330
 331 /*
 332  * Structure that defines an entry function trace.
 333  */
 334 struct ftrace_graph_ent {
 335         unsigned long func; /* Current function */
 336         int depth;
 337 };
 338
 339 /*
 340  * Structure that defines a return function trace.
 341  */
 342 struct ftrace_graph_ret {
 343         unsigned long func; /* Current function */
 344         unsigned long long calltime;
 345         unsigned long long rettime;
 346         /* Number of functions that overran the depth limit for current task */
 347         unsigned long overrun;
 348         int depth;
 349 };
 350
 351 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 352
 353 /*
 354  * Stack of return addresses for functions
 355  * of a thread.
 356  * Used in struct thread_info
 357  */
 358 struct ftrace_ret_stack {
 359         unsigned long ret;
 360         unsigned long func;
 361         unsigned long long calltime;
 362 };
 363
 364 /*
 365  * Primary handler of a function return.
 366  * It relays on ftrace_return_to_handler.
 367  * Defined in entry_32/64.S
 368  */
 369 extern void return_to_handler(void);
 370
 371 extern int
 372 ftrace_push_return_trace(unsigned long ret, unsigned long long time,
 373                          unsigned long func, int *depth);
 374 extern void
 375 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret);
 376
 377 /*
 378  * Sometimes we don't want to trace a function with the function
 379  * graph tracer but we want them to keep traced by the usual function
 380  * tracer if the function graph tracer is not configured.
 381  */
 382 #define __notrace_funcgraph             notrace
 383
 384 /*
 385  * We want to which function is an entrypoint of a hardirq.
 386  * That will help us to put a signal on output.
 387  */
 388 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 389
 390 /* Limits of hardirq entrypoints */
 391 extern char __irqentry_text_start[];
 392 extern char __irqentry_text_end[];
 393
 394 #define FTRACE_RETFUNC_DEPTH 50
 395 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 396 /* Type of the callback handlers for tracing function graph*/
 397 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 398 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 399
 400 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 401                                 trace_func_graph_ent_t entryfunc);
 402
 403 extern void ftrace_graph_stop(void);
 404
 405 /* The current handlers in use */
 406 extern trace_func_graph_ret_t ftrace_graph_return;
 407 extern trace_func_graph_ent_t ftrace_graph_entry;
 408
 409 extern void unregister_ftrace_graph(void);
 410
 411 extern void ftrace_graph_init_task(struct task_struct *t);
 412 extern void ftrace_graph_exit_task(struct task_struct *t);
 413
 414 static inline int task_curr_ret_stack(struct task_struct *t)
 415 {
 416         return t->curr_ret_stack;
 417 }
 418
 419 static inline void pause_graph_tracing(void)
 420 {
 421         atomic_inc(&current->tracing_graph_pause);
 422 }
 423
 424 static inline void unpause_graph_tracing(void)
 425 {
 426         atomic_dec(&current->tracing_graph_pause);
 427 }
 428 #else
 429
 430 #define __notrace_funcgraph
 431 #define __irq_entry
 432
 433 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 434 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 435
 436 static inline int task_curr_ret_stack(struct task_struct *tsk)
 437 {
 438         return -1;
 439 }
 440
 441 static inline void pause_graph_tracing(void) { }
 442 static inline void unpause_graph_tracing(void) { }
 443 #endif
 444
 445 #ifdef CONFIG_TRACING
 446 #include <linux/sched.h>
 447
 448 /* flags for current->trace */
 449 enum {
 450         TSK_TRACE_FL_TRACE_BIT  = 0,
 451         TSK_TRACE_FL_GRAPH_BIT  = 1,
 452 };
 453 enum {
 454         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 455         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 456 };
 457
 458 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 459 {
 460         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 461 }
 462
 463 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 464 {
 465         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 466 }
 467
 468 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 469 {
 470         return tsk->trace & TSK_TRACE_FL_TRACE;
 471 }
 472
 473 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 474 {
 475         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 476 }
 477
 478 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 479 {
 480         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 481 }
 482
 483 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 484 {
 485         return tsk->trace & TSK_TRACE_FL_GRAPH;
 486 }
 487
 488 extern int ftrace_dump_on_oops;
 489
 490 #endif /* CONFIG_TRACING */
 491
 492
 493 #ifdef CONFIG_HW_BRANCH_TRACER
 494
 495 void trace_hw_branch(u64 from, u64 to);
 496 void trace_hw_branch_oops(void);
 497
 498 #else /* CONFIG_HW_BRANCH_TRACER */
 499
 500 static inline void trace_hw_branch(u64 from, u64 to) {}
 501 static inline void trace_hw_branch_oops(void) {}
 502
 503 #endif /* CONFIG_HW_BRANCH_TRACER */
 504
 505 /*
 506  * A syscall entry in the ftrace syscalls array.
 507  *
 508  * @name: name of the syscall
 509  * @nb_args: number of parameters it takes
 510  * @types: list of types as strings
 511  * @args: list of args as strings (args[i] matches types[i])
 512  */
 513 struct syscall_metadata {
 514         const char      *name;
 515         int             nb_args;
 516         const char      **types;
 517         const char      **args;
 518 };
 519
 520 #ifdef CONFIG_FTRACE_SYSCALLS
 521 extern void arch_init_ftrace_syscalls(void);
 522 extern struct syscall_metadata *syscall_nr_to_meta(int nr);
 523 extern void start_ftrace_syscalls(void);
 524 extern void stop_ftrace_syscalls(void);
 525 extern void ftrace_syscall_enter(struct pt_regs *regs);
 526 extern void ftrace_syscall_exit(struct pt_regs *regs);
 527 #else
 528 static inline void start_ftrace_syscalls(void) { }
 529 static inline void stop_ftrace_syscalls(void) { }
 530 static inline void ftrace_syscall_enter(struct pt_regs *regs) { }
 531 static inline void ftrace_syscall_exit(struct pt_regs *regs) { }
 532 #endif
 533
 534 #endif /* _LINUX_FTRACE_H */