| #ifndef _LINUX_KERNEL_TRACE_H |
| #define _LINUX_KERNEL_TRACE_H |
| |
| #include <linux/fs.h> |
| #include <asm/atomic.h> |
| #include <linux/sched.h> |
| #include <linux/clocksource.h> |
| #include <linux/ring_buffer.h> |
| #include <linux/mmiotrace.h> |
| #include <linux/ftrace.h> |
| #include <trace/boot.h> |
| #include <trace/kmemtrace.h> |
| #include <trace/power.h> |
| |
| enum trace_type { |
| __TRACE_FIRST_TYPE = 0, |
| |
| TRACE_FN, |
| TRACE_CTX, |
| TRACE_WAKE, |
| TRACE_STACK, |
| TRACE_PRINT, |
| TRACE_SPECIAL, |
| TRACE_MMIO_RW, |
| TRACE_MMIO_MAP, |
| TRACE_BRANCH, |
| TRACE_BOOT_CALL, |
| TRACE_BOOT_RET, |
| TRACE_GRAPH_RET, |
| TRACE_GRAPH_ENT, |
| TRACE_USER_STACK, |
| TRACE_HW_BRANCHES, |
| TRACE_KMEM_ALLOC, |
| TRACE_KMEM_FREE, |
| TRACE_POWER, |
| TRACE_BLK, |
| |
| __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 flags; |
| unsigned char preempt_count; |
| int pid; |
| int tgid; |
| }; |
| |
| /* |
| * Function trace entry - function address and parent function addres: |
| */ |
| struct ftrace_entry { |
| struct trace_entry ent; |
| unsigned long ip; |
| unsigned long parent_ip; |
| }; |
| |
| /* Function call entry */ |
| struct ftrace_graph_ent_entry { |
| struct trace_entry ent; |
| struct ftrace_graph_ent graph_ent; |
| }; |
| |
| /* Function return entry */ |
| struct ftrace_graph_ret_entry { |
| struct trace_entry ent; |
| struct ftrace_graph_ret ret; |
| }; |
| 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]; |
| }; |
| |
| struct userstack_entry { |
| struct trace_entry ent; |
| unsigned long caller[FTRACE_STACK_ENTRIES]; |
| }; |
| |
| /* |
| * trace_printk entry: |
| */ |
| struct print_entry { |
| struct trace_entry ent; |
| unsigned long ip; |
| int depth; |
| const char *fmt; |
| u32 buf[]; |
| }; |
| #ifdef CONFIG_TRACE_BPRINTK |
| extern int trace_bprintk_enable; |
| #endif |
| |
| #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_call { |
| struct trace_entry ent; |
| struct boot_trace_call boot_call; |
| }; |
| |
| struct trace_boot_ret { |
| struct trace_entry ent; |
| struct boot_trace_ret boot_ret; |
| }; |
| |
| #define TRACE_FUNC_SIZE 30 |
| #define TRACE_FILE_SIZE 20 |
| struct trace_branch { |
| struct trace_entry ent; |
| unsigned line; |
| char func[TRACE_FUNC_SIZE+1]; |
| char file[TRACE_FILE_SIZE+1]; |
| char correct; |
| }; |
| |
| struct hw_branch_entry { |
| struct trace_entry ent; |
| u64 from; |
| u64 to; |
| }; |
| |
| struct trace_power { |
| struct trace_entry ent; |
| struct power_trace state_data; |
| }; |
| |
| struct kmemtrace_alloc_entry { |
| struct trace_entry ent; |
| enum kmemtrace_type_id type_id; |
| unsigned long call_site; |
| const void *ptr; |
| size_t bytes_req; |
| size_t bytes_alloc; |
| gfp_t gfp_flags; |
| int node; |
| }; |
| |
| struct kmemtrace_free_entry { |
| struct trace_entry ent; |
| enum kmemtrace_type_id type_id; |
| unsigned long call_site; |
| const void *ptr; |
| }; |
| |
| /* |
| * 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 |
| */ |
| 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, |
| }; |
| |
| #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; |
| void *buffer_page; /* ring buffer spare */ |
| |
| /* 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; |
| 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 stack_entry, TRACE_STACK); \ |
| IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_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_call, TRACE_BOOT_CALL);\ |
| IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\ |
| IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \ |
| IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \ |
| TRACE_GRAPH_ENT); \ |
| IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ |
| TRACE_GRAPH_RET); \ |
| IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ |
| IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \ |
| IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \ |
| TRACE_KMEM_ALLOC); \ |
| IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ |
| TRACE_KMEM_FREE); \ |
| __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 */ |
| TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */ |
| }; |
| |
| |
| /* |
| * An option specific to a tracer. This is a boolean value. |
| * The bit is the bit index that sets its value on the |
| * flags value in struct tracer_flags. |
| */ |
| struct tracer_opt { |
| const char *name; /* Will appear on the trace_options file */ |
| u32 bit; /* Mask assigned in val field in tracer_flags */ |
| }; |
| |
| /* |
| * The set of specific options for a tracer. Your tracer |
| * have to set the initial value of the flags val. |
| */ |
| struct tracer_flags { |
| u32 val; |
| struct tracer_opt *opts; |
| }; |
| |
| /* Makes more easy to define a tracer opt */ |
| #define TRACER_OPT(s, b) .name = #s, .bit = b |
| |
| |
| /** |
| * struct tracer - a specific tracer and its callbacks to interact with debugfs |
| * @name: the name chosen to select it on the available_tracers file |
| * @init: called when one switches to this tracer (echo name > current_tracer) |
| * @reset: called when one switches to another tracer |
| * @start: called when tracing is unpaused (echo 1 > tracing_enabled) |
| * @stop: called when tracing is paused (echo 0 > tracing_enabled) |
| * @open: called when the trace file is opened |
| * @pipe_open: called when the trace_pipe file is opened |
| * @wait_pipe: override how the user waits for traces on trace_pipe |
| * @close: called when the trace file is released |
| * @read: override the default read callback on trace_pipe |
| * @splice_read: override the default splice_read callback on trace_pipe |
| * @selftest: selftest to run on boot (see trace_selftest.c) |
| * @print_headers: override the first lines that describe your columns |
| * @print_line: callback that prints a trace |
| * @set_flag: signals one of your private flags changed (trace_options file) |
| * @flags: your private flags |
| */ |
| struct tracer { |
| const char *name; |
| int (*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 (*wait_pipe)(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); |
| ssize_t (*splice_read)(struct trace_iterator *iter, |
| struct file *filp, |
| loff_t *ppos, |
| struct pipe_inode_info *pipe, |
| size_t len, |
| unsigned int flags); |
| #ifdef CONFIG_FTRACE_STARTUP_TEST |
| int (*selftest)(struct tracer *trace, |
| struct trace_array *tr); |
| #endif |
| void (*print_header)(struct seq_file *m); |
| enum print_line_t (*print_line)(struct trace_iterator *iter); |
| /* If you handled the flag setting, return 0 */ |
| int (*set_flag)(u32 old_flags, u32 bit, int set); |
| struct tracer *next; |
| int print_max; |
| struct tracer_flags *flags; |
| struct tracer_stat *stats; |
| }; |
| |
| struct trace_seq { |
| unsigned char buffer[PAGE_SIZE]; |
| unsigned int len; |
| unsigned int readpos; |
| }; |
| |
| static inline void |
| trace_seq_init(struct trace_seq *s) |
| { |
| s->len = 0; |
| s->readpos = 0; |
| } |
| |
| |
| #define TRACE_PIPE_ALL_CPU -1 |
| |
| /* |
| * 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; |
| int cpu_file; |
| struct mutex mutex; |
| 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; |
| |
| cpumask_var_t started; |
| }; |
| |
| int tracer_init(struct tracer *t, struct trace_array *tr); |
| int tracing_is_enabled(void); |
| void trace_wake_up(void); |
| void tracing_reset(struct trace_array *tr, int cpu); |
| void tracing_reset_online_cpus(struct trace_array *tr); |
| 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 ring_buffer_event; |
| |
| struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr, |
| unsigned char type, |
| unsigned long len, |
| unsigned long flags, |
| int pc); |
| void trace_buffer_unlock_commit(struct trace_array *tr, |
| struct ring_buffer_event *event, |
| unsigned long flags, int pc); |
| |
| struct ring_buffer_event * |
| trace_current_buffer_lock_reserve(unsigned char type, unsigned long len, |
| unsigned long flags, int pc); |
| void trace_current_buffer_unlock_commit(struct ring_buffer_event *event, |
| unsigned long flags, int pc); |
| |
| struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, |
| struct trace_array_cpu *data); |
| |
| struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
| int *ent_cpu, u64 *ent_ts); |
| |
| void tracing_generic_entry_update(struct trace_entry *entry, |
| unsigned long flags, |
| int pc); |
| |
| void default_wait_pipe(struct trace_iterator *iter); |
| void poll_wait_pipe(struct trace_iterator *iter); |
| |
| 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 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 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, |
| unsigned long ip, |
| unsigned long parent_ip, |
| unsigned long flags, int pc); |
| |
| void trace_graph_return(struct ftrace_graph_ret *trace); |
| int trace_graph_entry(struct ftrace_graph_ent *trace); |
| |
| void tracing_start_cmdline_record(void); |
| void tracing_stop_cmdline_record(void); |
| void tracing_sched_switch_assign_trace(struct trace_array *tr); |
| void tracing_stop_sched_switch_record(void); |
| void tracing_start_sched_switch_record(void); |
| 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); |
| |
| void __trace_stack(struct trace_array *tr, |
| unsigned long flags, |
| int skip, int pc); |
| |
| extern cycle_t ftrace_now(int cpu); |
| |
| #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 */ |
| |
| extern char *trace_find_cmdline(int pid); |
| |
| #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_function_graph(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); |
| extern int trace_selftest_startup_branch(struct tracer *trace, |
| struct trace_array *tr); |
| #endif /* CONFIG_FTRACE_STARTUP_TEST */ |
| |
| extern void *head_page(struct trace_array_cpu *data); |
| extern long ns2usecs(cycle_t nsec); |
| extern int |
| trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args); |
| |
| extern unsigned long trace_flags; |
| |
| /* Standard output formatting function used for function return traces */ |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| extern enum print_line_t print_graph_function(struct trace_iterator *iter); |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| /* TODO: make this variable */ |
| #define FTRACE_GRAPH_MAX_FUNCS 32 |
| extern int ftrace_graph_count; |
| extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS]; |
| |
| static inline int ftrace_graph_addr(unsigned long addr) |
| { |
| int i; |
| |
| if (!ftrace_graph_count || test_tsk_trace_graph(current)) |
| return 1; |
| |
| for (i = 0; i < ftrace_graph_count; i++) { |
| if (addr == ftrace_graph_funcs[i]) |
| return 1; |
| } |
| |
| return 0; |
| } |
| #else |
| static inline int ftrace_trace_addr(unsigned long addr) |
| { |
| return 1; |
| } |
| static inline int ftrace_graph_addr(unsigned long addr) |
| { |
| return 1; |
| } |
| #endif /* CONFIG_DYNAMIC_FTRACE */ |
| |
| #else /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| static inline enum print_line_t |
| print_graph_function(struct trace_iterator *iter) |
| { |
| return TRACE_TYPE_UNHANDLED; |
| } |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| |
| extern struct pid *ftrace_pid_trace; |
| |
| static inline int ftrace_trace_task(struct task_struct *task) |
| { |
| if (!ftrace_pid_trace) |
| return 1; |
| |
| return test_tsk_trace_trace(task); |
| } |
| |
| /* |
| * 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, |
| TRACE_ITER_BRANCH = 0x1000, |
| TRACE_ITER_ANNOTATE = 0x2000, |
| TRACE_ITER_USERSTACKTRACE = 0x4000, |
| TRACE_ITER_SYM_USEROBJ = 0x8000, |
| TRACE_ITER_PRINTK_MSGONLY = 0x10000, |
| TRACE_ITER_CONTEXT_INFO = 0x20000, /* Print pid/cpu/time */ |
| TRACE_ITER_LATENCY_FMT = 0x40000, |
| }; |
| |
| /* |
| * TRACE_ITER_SYM_MASK masks the options in trace_flags that |
| * control the output of kernel symbols. |
| */ |
| #define TRACE_ITER_SYM_MASK \ |
| (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) |
| |
| 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_resched 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 are 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(); |
| } |
| |
| #ifdef CONFIG_BRANCH_TRACER |
| extern int enable_branch_tracing(struct trace_array *tr); |
| extern void disable_branch_tracing(void); |
| static inline int trace_branch_enable(struct trace_array *tr) |
| { |
| if (trace_flags & TRACE_ITER_BRANCH) |
| return enable_branch_tracing(tr); |
| return 0; |
| } |
| static inline void trace_branch_disable(void) |
| { |
| /* due to races, always disable */ |
| disable_branch_tracing(); |
| } |
| #else |
| static inline int trace_branch_enable(struct trace_array *tr) |
| { |
| return 0; |
| } |
| static inline void trace_branch_disable(void) |
| { |
| } |
| #endif /* CONFIG_BRANCH_TRACER */ |
| |
| /* trace event type bit fields, not numeric */ |
| enum { |
| TRACE_EVENT_TYPE_PRINTF = 1, |
| TRACE_EVENT_TYPE_RAW = 2, |
| }; |
| |
| struct ftrace_event_call { |
| char *name; |
| char *system; |
| struct dentry *dir; |
| int enabled; |
| int (*regfunc)(void); |
| void (*unregfunc)(void); |
| int id; |
| struct dentry *raw_dir; |
| int raw_enabled; |
| int type; |
| int (*raw_init)(void); |
| int (*raw_reg)(void); |
| void (*raw_unreg)(void); |
| int (*show_format)(struct trace_seq *s); |
| }; |
| |
| void event_trace_printk(unsigned long ip, const char *fmt, ...); |
| extern struct ftrace_event_call __start_ftrace_events[]; |
| extern struct ftrace_event_call __stop_ftrace_events[]; |
| |
| #endif /* _LINUX_KERNEL_TRACE_H */ |