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         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_release(void *start, unsigned long size);
 237
 238 extern void ftrace_disable_daemon(void);
 239 extern void ftrace_enable_daemon(void);
 240 #else
 241 # define skip_trace(ip)                         ({ 0; })
 242 # define ftrace_force_update()                  ({ 0; })
 243 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
 244 # define ftrace_disable_daemon()                do { } while (0)
 245 # define ftrace_enable_daemon()                 do { } while (0)
 246 static inline void ftrace_release(void *start, unsigned long size) { }
 247 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
 248 {
 249         return -EINVAL;
 250 }
 251 static inline int unregister_ftrace_command(char *cmd_name)
 252 {
 253         return -EINVAL;
 254 }
 255 #endif /* CONFIG_DYNAMIC_FTRACE */
 256
 257 /* totally disable ftrace - can not re-enable after this */
 258 void ftrace_kill(void);
 259
 260 static inline void tracer_disable(void)
 261 {
 262 #ifdef CONFIG_FUNCTION_TRACER
 263         ftrace_enabled = 0;
 264 #endif
 265 }
 266
 267 /*
 268  * Ftrace disable/restore without lock. Some synchronization mechanism
 269  * must be used to prevent ftrace_enabled to be changed between
 270  * disable/restore.
 271  */
 272 static inline int __ftrace_enabled_save(void)
 273 {
 274 #ifdef CONFIG_FUNCTION_TRACER
 275         int saved_ftrace_enabled = ftrace_enabled;
 276         ftrace_enabled = 0;
 277         return saved_ftrace_enabled;
 278 #else
 279         return 0;
 280 #endif
 281 }
 282
 283 static inline void __ftrace_enabled_restore(int enabled)
 284 {
 285 #ifdef CONFIG_FUNCTION_TRACER
 286         ftrace_enabled = enabled;
 287 #endif
 288 }
 289
 290 #ifndef HAVE_ARCH_CALLER_ADDR
 291 # ifdef CONFIG_FRAME_POINTER
 292 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 293 #  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 294 #  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 295 #  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 296 #  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 297 #  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 298 #  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 299 # else
 300 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 301 #  define CALLER_ADDR1 0UL
 302 #  define CALLER_ADDR2 0UL
 303 #  define CALLER_ADDR3 0UL
 304 #  define CALLER_ADDR4 0UL
 305 #  define CALLER_ADDR5 0UL
 306 #  define CALLER_ADDR6 0UL
 307 # endif
 308 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
 309
 310 #ifdef CONFIG_IRQSOFF_TRACER
 311   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 312   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 313 #else
 314 # define time_hardirqs_on(a0, a1)               do { } while (0)
 315 # define time_hardirqs_off(a0, a1)              do { } while (0)
 316 #endif
 317
 318 #ifdef CONFIG_PREEMPT_TRACER
 319   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 320   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 321 #else
 322 # define trace_preempt_on(a0, a1)               do { } while (0)
 323 # define trace_preempt_off(a0, a1)              do { } while (0)
 324 #endif
 325
 326 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 327 extern void ftrace_init(void);
 328 extern void ftrace_init_module(struct module *mod,
 329                                unsigned long *start, unsigned long *end);
 330 #else
 331 static inline void ftrace_init(void) { }
 332 static inline void
 333 ftrace_init_module(struct module *mod,
 334                    unsigned long *start, unsigned long *end) { }
 335 #endif
 336
 337 /*
 338  * Structure that defines an entry function trace.
 339  */
 340 struct ftrace_graph_ent {
 341         unsigned long func; /* Current function */
 342         int depth;
 343 };
 344
 345 /*
 346  * Structure that defines a return function trace.
 347  */
 348 struct ftrace_graph_ret {
 349         unsigned long func; /* Current function */
 350         unsigned long long calltime;
 351         unsigned long long rettime;
 352         /* Number of functions that overran the depth limit for current task */
 353         unsigned long overrun;
 354         int depth;
 355 };
 356
 357 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 358
 359 /*
 360  * Stack of return addresses for functions
 361  * of a thread.
 362  * Used in struct thread_info
 363  */
 364 struct ftrace_ret_stack {
 365         unsigned long ret;
 366         unsigned long func;
 367         unsigned long long calltime;
 368 };
 369
 370 /*
 371  * Primary handler of a function return.
 372  * It relays on ftrace_return_to_handler.
 373  * Defined in entry_32/64.S
 374  */
 375 extern void return_to_handler(void);
 376
 377 extern int
 378 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth);
 379 extern void
 380 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret);
 381
 382 /*
 383  * Sometimes we don't want to trace a function with the function
 384  * graph tracer but we want them to keep traced by the usual function
 385  * tracer if the function graph tracer is not configured.
 386  */
 387 #define __notrace_funcgraph             notrace
 388
 389 /*
 390  * We want to which function is an entrypoint of a hardirq.
 391  * That will help us to put a signal on output.
 392  */
 393 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
 394
 395 /* Limits of hardirq entrypoints */
 396 extern char __irqentry_text_start[];
 397 extern char __irqentry_text_end[];
 398
 399 #define FTRACE_RETFUNC_DEPTH 50
 400 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 401 /* Type of the callback handlers for tracing function graph*/
 402 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
 403 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 404
 405 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 406                                 trace_func_graph_ent_t entryfunc);
 407
 408 extern void ftrace_graph_stop(void);
 409
 410 /* The current handlers in use */
 411 extern trace_func_graph_ret_t ftrace_graph_return;
 412 extern trace_func_graph_ent_t ftrace_graph_entry;
 413
 414 extern void unregister_ftrace_graph(void);
 415
 416 extern void ftrace_graph_init_task(struct task_struct *t);
 417 extern void ftrace_graph_exit_task(struct task_struct *t);
 418
 419 static inline int task_curr_ret_stack(struct task_struct *t)
 420 {
 421         return t->curr_ret_stack;
 422 }
 423
 424 static inline void pause_graph_tracing(void)
 425 {
 426         atomic_inc(&current->tracing_graph_pause);
 427 }
 428
 429 static inline void unpause_graph_tracing(void)
 430 {
 431         atomic_dec(&current->tracing_graph_pause);
 432 }
 433 #else
 434
 435 #define __notrace_funcgraph
 436 #define __irq_entry
 437
 438 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 439 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 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
 449
 450 #ifdef CONFIG_TRACING
 451 #include <linux/sched.h>
 452
 453 /* flags for current->trace */
 454 enum {
 455         TSK_TRACE_FL_TRACE_BIT  = 0,
 456         TSK_TRACE_FL_GRAPH_BIT  = 1,
 457 };
 458 enum {
 459         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
 460         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
 461 };
 462
 463 static inline void set_tsk_trace_trace(struct task_struct *tsk)
 464 {
 465         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 466 }
 467
 468 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
 469 {
 470         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
 471 }
 472
 473 static inline int test_tsk_trace_trace(struct task_struct *tsk)
 474 {
 475         return tsk->trace & TSK_TRACE_FL_TRACE;
 476 }
 477
 478 static inline void set_tsk_trace_graph(struct task_struct *tsk)
 479 {
 480         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 481 }
 482
 483 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
 484 {
 485         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
 486 }
 487
 488 static inline int test_tsk_trace_graph(struct task_struct *tsk)
 489 {
 490         return tsk->trace & TSK_TRACE_FL_GRAPH;
 491 }
 492
 493 extern int ftrace_dump_on_oops;
 494
 495 #endif /* CONFIG_TRACING */
 496
 497
 498 #ifdef CONFIG_HW_BRANCH_TRACER
 499
 500 void trace_hw_branch(u64 from, u64 to);
 501 void trace_hw_branch_oops(void);
 502
 503 #else /* CONFIG_HW_BRANCH_TRACER */
 504
 505 static inline void trace_hw_branch(u64 from, u64 to) {}
 506 static inline void trace_hw_branch_oops(void) {}
 507
 508 #endif /* CONFIG_HW_BRANCH_TRACER */
 509
 510 /*
 511  * A syscall entry in the ftrace syscalls array.
 512  *
 513  * @name: name of the syscall
 514  * @nb_args: number of parameters it takes
 515  * @types: list of types as strings
 516  * @args: list of args as strings (args[i] matches types[i])
 517  */
 518 struct syscall_metadata {
 519         const char      *name;
 520         int             nb_args;
 521         const char      **types;
 522         const char      **args;
 523 };
 524
 525 #ifdef CONFIG_FTRACE_SYSCALLS
 526 extern void arch_init_ftrace_syscalls(void);
 527 extern struct syscall_metadata *syscall_nr_to_meta(int nr);
 528 extern void start_ftrace_syscalls(void);
 529 extern void stop_ftrace_syscalls(void);
 530 extern void ftrace_syscall_enter(struct pt_regs *regs);
 531 extern void ftrace_syscall_exit(struct pt_regs *regs);
 532 #else
 533 static inline void start_ftrace_syscalls(void) { }
 534 static inline void stop_ftrace_syscalls(void) { }
 535 static inline void ftrace_syscall_enter(struct pt_regs *regs) { }
 536 static inline void ftrace_syscall_exit(struct pt_regs *regs) { }
 537 #endif
 538
 539 #endif /* _LINUX_FTRACE_H */