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/kallsyms.h>
  10
  11 #ifdef CONFIG_FUNCTION_TRACER
  12
  13 extern int ftrace_enabled;
  14 extern int
  15 ftrace_enable_sysctl(struct ctl_table *table, int write,
  16                      struct file *filp, void __user *buffer, size_t *lenp,
  17                      loff_t *ppos);
  18
  19 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
  20
  21 struct ftrace_ops {
  22         ftrace_func_t     func;
  23         struct ftrace_ops *next;
  24 };
  25
  26 /*
  27  * The ftrace_ops must be a static and should also
  28  * be read_mostly.  These functions do modify read_mostly variables
  29  * so use them sparely. Never free an ftrace_op or modify the
  30  * next pointer after it has been registered. Even after unregistering
  31  * it, the next pointer may still be used internally.
  32  */
  33 int register_ftrace_function(struct ftrace_ops *ops);
  34 int unregister_ftrace_function(struct ftrace_ops *ops);
  35 void clear_ftrace_function(void);
  36
  37 extern void ftrace_stub(unsigned long a0, unsigned long a1);
  38
  39 #else /* !CONFIG_FUNCTION_TRACER */
  40 # define register_ftrace_function(ops) do { } while (0)
  41 # define unregister_ftrace_function(ops) do { } while (0)
  42 # define clear_ftrace_function(ops) do { } while (0)
  43 static inline void ftrace_kill_atomic(void) { }
  44 #endif /* CONFIG_FUNCTION_TRACER */
  45
  46 #ifdef CONFIG_DYNAMIC_FTRACE
  47 # define FTRACE_HASHBITS        10
  48 # define FTRACE_HASHSIZE        (1<<FTRACE_HASHBITS)
  49
  50 enum {
  51         FTRACE_FL_FREE          = (1 << 0),
  52         FTRACE_FL_FAILED        = (1 << 1),
  53         FTRACE_FL_FILTER        = (1 << 2),
  54         FTRACE_FL_ENABLED       = (1 << 3),
  55         FTRACE_FL_NOTRACE       = (1 << 4),
  56         FTRACE_FL_CONVERTED     = (1 << 5),
  57         FTRACE_FL_FROZEN        = (1 << 6),
  58 };
  59
  60 struct dyn_ftrace {
  61         struct hlist_node node;
  62         unsigned long     ip; /* address of mcount call-site */
  63         unsigned long     flags;
  64 };
  65
  66 int ftrace_force_update(void);
  67 void ftrace_set_filter(unsigned char *buf, int len, int reset);
  68
  69 /* defined in arch */
  70 extern int ftrace_ip_converted(unsigned long ip);
  71 extern unsigned char *ftrace_nop_replace(void);
  72 extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr);
  73 extern int ftrace_dyn_arch_init(void *data);
  74 extern int ftrace_mcount_set(unsigned long *data);
  75 extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
  76                               unsigned char *new_code);
  77 extern int ftrace_update_ftrace_func(ftrace_func_t func);
  78 extern void ftrace_caller(void);
  79 extern void ftrace_call(void);
  80 extern void mcount_call(void);
  81
  82 extern int skip_trace(unsigned long ip);
  83
  84 extern void ftrace_release(void *start, unsigned long size);
  85
  86 extern void ftrace_disable_daemon(void);
  87 extern void ftrace_enable_daemon(void);
  88
  89 #else
  90 # define skip_trace(ip)                         ({ 0; })
  91 # define ftrace_force_update()                  ({ 0; })
  92 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
  93 # define ftrace_disable_daemon()                do { } while (0)
  94 # define ftrace_enable_daemon()                 do { } while (0)
  95 static inline void ftrace_release(void *start, unsigned long size) { }
  96 #endif /* CONFIG_DYNAMIC_FTRACE */
  97
  98 /* totally disable ftrace - can not re-enable after this */
  99 void ftrace_kill(void);
 100 void ftrace_kill_atomic(void);
 101
 102 static inline void tracer_disable(void)
 103 {
 104 #ifdef CONFIG_FUNCTION_TRACER
 105         ftrace_enabled = 0;
 106 #endif
 107 }
 108
 109 /*
 110  * Ftrace disable/restore without lock. Some synchronization mechanism
 111  * must be used to prevent ftrace_enabled to be changed between
 112  * disable/restore.
 113  */
 114 static inline int __ftrace_enabled_save(void)
 115 {
 116 #ifdef CONFIG_FUNCTION_TRACER
 117         int saved_ftrace_enabled = ftrace_enabled;
 118         ftrace_enabled = 0;
 119         return saved_ftrace_enabled;
 120 #else
 121         return 0;
 122 #endif
 123 }
 124
 125 static inline void __ftrace_enabled_restore(int enabled)
 126 {
 127 #ifdef CONFIG_FUNCTION_TRACER
 128         ftrace_enabled = enabled;
 129 #endif
 130 }
 131
 132 #ifdef CONFIG_FRAME_POINTER
 133 /* TODO: need to fix this for ARM */
 134 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 135 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 136 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 137 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 138 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 139 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 140 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 141 #else
 142 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 143 # define CALLER_ADDR1 0UL
 144 # define CALLER_ADDR2 0UL
 145 # define CALLER_ADDR3 0UL
 146 # define CALLER_ADDR4 0UL
 147 # define CALLER_ADDR5 0UL
 148 # define CALLER_ADDR6 0UL
 149 #endif
 150
 151 #ifdef CONFIG_IRQSOFF_TRACER
 152   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 153   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 154 #else
 155 # define time_hardirqs_on(a0, a1)               do { } while (0)
 156 # define time_hardirqs_off(a0, a1)              do { } while (0)
 157 #endif
 158
 159 #ifdef CONFIG_PREEMPT_TRACER
 160   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 161   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 162 #else
 163 # define trace_preempt_on(a0, a1)               do { } while (0)
 164 # define trace_preempt_off(a0, a1)              do { } while (0)
 165 #endif
 166
 167 #ifdef CONFIG_TRACING
 168 extern void
 169 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
 170
 171 /**
 172  * ftrace_printk - printf formatting in the ftrace buffer
 173  * @fmt: the printf format for printing
 174  *
 175  * Note: __ftrace_printk is an internal function for ftrace_printk and
 176  *       the @ip is passed in via the ftrace_printk macro.
 177  *
 178  * This function allows a kernel developer to debug fast path sections
 179  * that printk is not appropriate for. By scattering in various
 180  * printk like tracing in the code, a developer can quickly see
 181  * where problems are occurring.
 182  *
 183  * This is intended as a debugging tool for the developer only.
 184  * Please refrain from leaving ftrace_printks scattered around in
 185  * your code.
 186  */
 187 # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
 188 extern int
 189 __ftrace_printk(unsigned long ip, const char *fmt, ...)
 190         __attribute__ ((format (printf, 2, 3)));
 191 extern void ftrace_dump(void);
 192 #else
 193 static inline void
 194 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 195 static inline int
 196 ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 0)));
 197
 198 static inline int
 199 ftrace_printk(const char *fmt, ...)
 200 {
 201         return 0;
 202 }
 203 static inline void ftrace_dump(void) { }
 204 #endif
 205
 206 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 207 extern void ftrace_init(void);
 208 extern void ftrace_init_module(unsigned long *start, unsigned long *end);
 209 #else
 210 static inline void ftrace_init(void) { }
 211 static inline void
 212 ftrace_init_module(unsigned long *start, unsigned long *end) { }
 213 #endif
 214
 215
 216 struct boot_trace {
 217         pid_t                   caller;
 218         char                    func[KSYM_NAME_LEN];
 219         int                     result;
 220         unsigned long long      duration;               /* usecs */
 221         ktime_t                 calltime;
 222         ktime_t                 rettime;
 223 };
 224
 225 #ifdef CONFIG_BOOT_TRACER
 226 extern void trace_boot(struct boot_trace *it, initcall_t fn);
 227 extern void start_boot_trace(void);
 228 extern void stop_boot_trace(void);
 229 #else
 230 static inline void trace_boot(struct boot_trace *it, initcall_t fn) { }
 231 static inline void start_boot_trace(void) { }
 232 static inline void stop_boot_trace(void) { }
 233 #endif
 234
 235
 236
 237 #endif /* _LINUX_FTRACE_H */