#ifndef _LINUX_KERNEL_TRACE_H #define _LINUX_KERNEL_TRACE_H #include #include #include #include #include #include #include enum trace_type { __TRACE_FIRST_TYPE = 0, TRACE_FN, TRACE_CTX, TRACE_WAKE, TRACE_CONT, TRACE_STACK, TRACE_PRINT, TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, TRACE_BOOT, __TRACE_LAST_TYPE }; /* * The trace entry - the most basic unit of tracing. This is what * is printed in the end as a single line in the trace output, such as: * * bash-15816 [01] 235.197585: idle_cpu <- irq_enter */ struct trace_entry { unsigned char type; unsigned char cpu; unsigned char flags; unsigned char preempt_count; int pid; }; /* * Function trace entry - function address and parent function addres: */ struct ftrace_entry { struct trace_entry ent; unsigned long ip; unsigned long parent_ip; }; extern struct tracer boot_tracer; /* * Context switch trace entry - which task (and prio) we switched from/to: */ struct ctx_switch_entry { struct trace_entry ent; unsigned int prev_pid; unsigned char prev_prio; unsigned char prev_state; unsigned int next_pid; unsigned char next_prio; unsigned char next_state; unsigned int next_cpu; }; /* * Special (free-form) trace entry: */ struct special_entry { struct trace_entry ent; unsigned long arg1; unsigned long arg2; unsigned long arg3; }; /* * Stack-trace entry: */ #define FTRACE_STACK_ENTRIES 8 struct stack_entry { struct trace_entry ent; unsigned long caller[FTRACE_STACK_ENTRIES]; }; /* * ftrace_printk entry: */ struct print_entry { struct trace_entry ent; unsigned long ip; char buf[]; }; #define TRACE_OLD_SIZE 88 struct trace_field_cont { unsigned char type; /* Temporary till we get rid of this completely */ char buf[TRACE_OLD_SIZE - 1]; }; struct trace_mmiotrace_rw { struct trace_entry ent; struct mmiotrace_rw rw; }; struct trace_mmiotrace_map { struct trace_entry ent; struct mmiotrace_map map; }; struct trace_boot { struct trace_entry ent; struct boot_trace initcall; }; /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: * IRQS_OFF - interrupts were disabled * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags * NEED_RESCED - reschedule is requested * HARDIRQ - inside an interrupt handler * SOFTIRQ - inside a softirq handler * CONT - multiple entries hold the trace item */ enum trace_flag_type { TRACE_FLAG_IRQS_OFF = 0x01, TRACE_FLAG_IRQS_NOSUPPORT = 0x02, TRACE_FLAG_NEED_RESCHED = 0x04, TRACE_FLAG_HARDIRQ = 0x08, TRACE_FLAG_SOFTIRQ = 0x10, TRACE_FLAG_CONT = 0x20, }; #define TRACE_BUF_SIZE 1024 /* * The CPU trace array - it consists of thousands of trace entries * plus some other descriptor data: (for example which task started * the trace, etc.) */ struct trace_array_cpu { atomic_t disabled; /* these fields get copied into max-trace: */ unsigned long trace_idx; unsigned long overrun; unsigned long saved_latency; unsigned long critical_start; unsigned long critical_end; unsigned long critical_sequence; unsigned long nice; unsigned long policy; unsigned long rt_priority; cycle_t preempt_timestamp; pid_t pid; uid_t uid; char comm[TASK_COMM_LEN]; }; struct trace_iterator; /* * The trace array - an array of per-CPU trace arrays. This is the * highest level data structure that individual tracers deal with. * They have on/off state as well: */ struct trace_array { struct ring_buffer *buffer; unsigned long entries; long ctrl; int cpu; cycle_t time_start; struct task_struct *waiter; struct trace_array_cpu *data[NR_CPUS]; }; #define FTRACE_CMP_TYPE(var, type) \ __builtin_types_compatible_p(typeof(var), type *) #undef IF_ASSIGN #define IF_ASSIGN(var, entry, etype, id) \ if (FTRACE_CMP_TYPE(var, etype)) { \ var = (typeof(var))(entry); \ WARN_ON(id && (entry)->type != id); \ break; \ } /* Will cause compile errors if type is not found. */ extern void __ftrace_bad_type(void); /* * The trace_assign_type is a verifier that the entry type is * the same as the type being assigned. To add new types simply * add a line with the following format: * * IF_ASSIGN(var, ent, type, id); * * Where "type" is the trace type that includes the trace_entry * as the "ent" item. And "id" is the trace identifier that is * used in the trace_type enum. * * If the type can have more than one id, then use zero. */ #define trace_assign_type(var, ent) \ do { \ IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \ IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \ IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \ IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ IF_ASSIGN(var, ent, struct special_entry, 0); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ TRACE_MMIO_RW); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ TRACE_MMIO_MAP); \ IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \ __ftrace_bad_type(); \ } while (0) /* Return values for print_line callback */ enum print_line_t { TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */ TRACE_TYPE_HANDLED = 1, TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */ }; /* * A specific tracer, represented by methods that operate on a trace array: */ struct tracer { const char *name; void (*init)(struct trace_array *tr); void (*reset)(struct trace_array *tr); void (*start)(struct trace_array *tr); void (*stop)(struct trace_array *tr); void (*open)(struct trace_iterator *iter); void (*pipe_open)(struct trace_iterator *iter); void (*close)(struct trace_iterator *iter); ssize_t (*read)(struct trace_iterator *iter, struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos); void (*ctrl_update)(struct trace_array *tr); #ifdef CONFIG_FTRACE_STARTUP_TEST int (*selftest)(struct tracer *trace, struct trace_array *tr); #endif enum print_line_t (*print_line)(struct trace_iterator *iter); struct tracer *next; int print_max; }; struct trace_seq { unsigned char buffer[PAGE_SIZE]; unsigned int len; unsigned int readpos; }; /* * Trace iterator - used by printout routines who present trace * results to users and which routines might sleep, etc: */ struct trace_iterator { struct trace_array *tr; struct tracer *trace; void *private; struct ring_buffer_iter *buffer_iter[NR_CPUS]; /* The below is zeroed out in pipe_read */ struct trace_seq seq; struct trace_entry *ent; int cpu; u64 ts; unsigned long iter_flags; loff_t pos; long idx; }; int tracing_is_enabled(void); void trace_wake_up(void); void tracing_reset(struct trace_array *tr, int cpu); int tracing_open_generic(struct inode *inode, struct file *filp); struct dentry *tracing_init_dentry(void); void init_tracer_sysprof_debugfs(struct dentry *d_tracer); struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data); void tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, int pc); void ftrace(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc); void tracing_sched_switch_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *prev, struct task_struct *next, unsigned long flags, int pc); void tracing_record_cmdline(struct task_struct *tsk); void tracing_sched_wakeup_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *wakee, struct task_struct *cur, unsigned long flags, int pc); void trace_special(struct trace_array *tr, struct trace_array_cpu *data, unsigned long arg1, unsigned long arg2, unsigned long arg3, int pc); void trace_function(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, unsigned long flags, int pc); void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); void tracing_cmdline_assign_trace(struct trace_array *tr); int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); extern unsigned long nsecs_to_usecs(unsigned long nsecs); extern unsigned long tracing_max_latency; extern unsigned long tracing_thresh; void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu); void update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu); extern cycle_t ftrace_now(int cpu); #ifdef CONFIG_FUNCTION_TRACER void tracing_start_function_trace(void); void tracing_stop_function_trace(void); #else # define tracing_start_function_trace() do { } while (0) # define tracing_stop_function_trace() do { } while (0) #endif #ifdef CONFIG_CONTEXT_SWITCH_TRACER typedef void (*tracer_switch_func_t)(void *private, void *__rq, struct task_struct *prev, struct task_struct *next); struct tracer_switch_ops { tracer_switch_func_t func; void *private; struct tracer_switch_ops *next; }; #endif /* CONFIG_CONTEXT_SWITCH_TRACER */ #ifdef CONFIG_DYNAMIC_FTRACE extern unsigned long ftrace_update_tot_cnt; #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func extern int DYN_FTRACE_TEST_NAME(void); #endif #ifdef CONFIG_FTRACE_STARTUP_TEST extern int trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr); #endif /* CONFIG_FTRACE_STARTUP_TEST */ extern void *head_page(struct trace_array_cpu *data); extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); extern void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter); extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt); extern long ns2usecs(cycle_t nsec); extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args); extern unsigned long trace_flags; /* * trace_iterator_flags is an enumeration that defines bit * positions into trace_flags that controls the output. * * NOTE: These bits must match the trace_options array in * trace.c. */ enum trace_iterator_flags { TRACE_ITER_PRINT_PARENT = 0x01, TRACE_ITER_SYM_OFFSET = 0x02, TRACE_ITER_SYM_ADDR = 0x04, TRACE_ITER_VERBOSE = 0x08, TRACE_ITER_RAW = 0x10, TRACE_ITER_HEX = 0x20, TRACE_ITER_BIN = 0x40, TRACE_ITER_BLOCK = 0x80, TRACE_ITER_STACKTRACE = 0x100, TRACE_ITER_SCHED_TREE = 0x200, TRACE_ITER_PRINTK = 0x400, TRACE_ITER_PREEMPTONLY = 0x800, }; extern struct tracer nop_trace; /** * ftrace_preempt_disable - disable preemption scheduler safe * * When tracing can happen inside the scheduler, there exists * cases that the tracing might happen before the need_resched * flag is checked. If this happens and the tracer calls * preempt_enable (after a disable), a schedule might take place * causing an infinite recursion. * * To prevent this, we read the need_recshed flag before * disabling preemption. When we want to enable preemption we * check the flag, if it is set, then we call preempt_enable_no_resched. * Otherwise, we call preempt_enable. * * The rational for doing the above is that if need resched is set * and we have yet to reschedule, we are either in an atomic location * (where we do not need to check for scheduling) or we are inside * the scheduler and do not want to resched. */ static inline int ftrace_preempt_disable(void) { int resched; resched = need_resched(); preempt_disable_notrace(); return resched; } /** * ftrace_preempt_enable - enable preemption scheduler safe * @resched: the return value from ftrace_preempt_disable * * This is a scheduler safe way to enable preemption and not miss * any preemption checks. The disabled saved the state of preemption. * If resched is set, then we were either inside an atomic or * are inside the scheduler (we would have already scheduled * otherwise). In this case, we do not want to call normal * preempt_enable, but preempt_enable_no_resched instead. */ static inline void ftrace_preempt_enable(int resched) { if (resched) preempt_enable_no_resched_notrace(); else preempt_enable_notrace(); } #endif /* _LINUX_KERNEL_TRACE_H */