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(void) { }
  44 #endif /* CONFIG_FUNCTION_TRACER */
  45
  46 #ifdef CONFIG_DYNAMIC_FTRACE
  47
  48 enum {
  49         FTRACE_FL_FREE          = (1 << 0),
  50         FTRACE_FL_FAILED        = (1 << 1),
  51         FTRACE_FL_FILTER        = (1 << 2),
  52         FTRACE_FL_ENABLED       = (1 << 3),
  53         FTRACE_FL_NOTRACE       = (1 << 4),
  54         FTRACE_FL_CONVERTED     = (1 << 5),
  55         FTRACE_FL_FROZEN        = (1 << 6),
  56 };
  57
  58 struct dyn_ftrace {
  59         struct list_head        list;
  60         unsigned long           ip; /* address of mcount call-site */
  61         unsigned long           flags;
  62 };
  63
  64 int ftrace_force_update(void);
  65 void ftrace_set_filter(unsigned char *buf, int len, int reset);
  66
  67 /* defined in arch */
  68 extern int ftrace_ip_converted(unsigned long ip);
  69 extern unsigned char *ftrace_nop_replace(void);
  70 extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr);
  71 extern int ftrace_dyn_arch_init(void *data);
  72 extern int ftrace_update_ftrace_func(ftrace_func_t func);
  73 extern void ftrace_caller(void);
  74 extern void ftrace_call(void);
  75 extern void mcount_call(void);
  76
  77 /**
  78  * ftrace_modify_code - modify code segment
  79  * @ip: the address of the code segment
  80  * @old_code: the contents of what is expected to be there
  81  * @new_code: the code to patch in
  82  *
  83  * This is a very sensitive operation and great care needs
  84  * to be taken by the arch.  The operation should carefully
  85  * read the location, check to see if what is read is indeed
  86  * what we expect it to be, and then on success of the compare,
  87  * it should write to the location.
  88  *
  89  * Return must be:
  90  *  0 on success
  91  *  -EFAULT on error reading the location
  92  *  -EINVAL on a failed compare of the contents
  93  *  -EPERM  on error writing to the location
  94  * Any other value will be considered a failure.
  95  */
  96 extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
  97                               unsigned char *new_code);
  98
  99 extern int skip_trace(unsigned long ip);
 100
 101 extern void ftrace_release(void *start, unsigned long size);
 102
 103 extern void ftrace_disable_daemon(void);
 104 extern void ftrace_enable_daemon(void);
 105
 106 #else
 107 # define skip_trace(ip)                         ({ 0; })
 108 # define ftrace_force_update()                  ({ 0; })
 109 # define ftrace_set_filter(buf, len, reset)     do { } while (0)
 110 # define ftrace_disable_daemon()                do { } while (0)
 111 # define ftrace_enable_daemon()                 do { } while (0)
 112 static inline void ftrace_release(void *start, unsigned long size) { }
 113 #endif /* CONFIG_DYNAMIC_FTRACE */
 114
 115 /* totally disable ftrace - can not re-enable after this */
 116 void ftrace_kill(void);
 117
 118 static inline void tracer_disable(void)
 119 {
 120 #ifdef CONFIG_FUNCTION_TRACER
 121         ftrace_enabled = 0;
 122 #endif
 123 }
 124
 125 /*
 126  * Ftrace disable/restore without lock. Some synchronization mechanism
 127  * must be used to prevent ftrace_enabled to be changed between
 128  * disable/restore.
 129  */
 130 static inline int __ftrace_enabled_save(void)
 131 {
 132 #ifdef CONFIG_FUNCTION_TRACER
 133         int saved_ftrace_enabled = ftrace_enabled;
 134         ftrace_enabled = 0;
 135         return saved_ftrace_enabled;
 136 #else
 137         return 0;
 138 #endif
 139 }
 140
 141 static inline void __ftrace_enabled_restore(int enabled)
 142 {
 143 #ifdef CONFIG_FUNCTION_TRACER
 144         ftrace_enabled = enabled;
 145 #endif
 146 }
 147
 148 #ifdef CONFIG_FRAME_POINTER
 149 /* TODO: need to fix this for ARM */
 150 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 151 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
 152 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
 153 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
 154 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
 155 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
 156 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
 157 #else
 158 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
 159 # define CALLER_ADDR1 0UL
 160 # define CALLER_ADDR2 0UL
 161 # define CALLER_ADDR3 0UL
 162 # define CALLER_ADDR4 0UL
 163 # define CALLER_ADDR5 0UL
 164 # define CALLER_ADDR6 0UL
 165 #endif
 166
 167 #ifdef CONFIG_IRQSOFF_TRACER
 168   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
 169   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
 170 #else
 171 # define time_hardirqs_on(a0, a1)               do { } while (0)
 172 # define time_hardirqs_off(a0, a1)              do { } while (0)
 173 #endif
 174
 175 #ifdef CONFIG_PREEMPT_TRACER
 176   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
 177   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
 178 #else
 179 # define trace_preempt_on(a0, a1)               do { } while (0)
 180 # define trace_preempt_off(a0, a1)              do { } while (0)
 181 #endif
 182
 183 #ifdef CONFIG_TRACING
 184 extern void
 185 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
 186
 187 /**
 188  * ftrace_printk - printf formatting in the ftrace buffer
 189  * @fmt: the printf format for printing
 190  *
 191  * Note: __ftrace_printk is an internal function for ftrace_printk and
 192  *       the @ip is passed in via the ftrace_printk macro.
 193  *
 194  * This function allows a kernel developer to debug fast path sections
 195  * that printk is not appropriate for. By scattering in various
 196  * printk like tracing in the code, a developer can quickly see
 197  * where problems are occurring.
 198  *
 199  * This is intended as a debugging tool for the developer only.
 200  * Please refrain from leaving ftrace_printks scattered around in
 201  * your code.
 202  */
 203 # define ftrace_printk(fmt...) __ftrace_printk(_THIS_IP_, fmt)
 204 extern int
 205 __ftrace_printk(unsigned long ip, const char *fmt, ...)
 206         __attribute__ ((format (printf, 2, 3)));
 207 extern void ftrace_dump(void);
 208 #else
 209 static inline void
 210 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 211 static inline int
 212 ftrace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 0)));
 213
 214 static inline int
 215 ftrace_printk(const char *fmt, ...)
 216 {
 217         return 0;
 218 }
 219 static inline void ftrace_dump(void) { }
 220 #endif
 221
 222 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 223 extern void ftrace_init(void);
 224 extern void ftrace_init_module(unsigned long *start, unsigned long *end);
 225 #else
 226 static inline void ftrace_init(void) { }
 227 static inline void
 228 ftrace_init_module(unsigned long *start, unsigned long *end) { }
 229 #endif
 230
 231
 232 struct boot_trace {
 233         pid_t                   caller;
 234         char                    func[KSYM_NAME_LEN];
 235         int                     result;
 236         unsigned long long      duration;               /* usecs */
 237         ktime_t                 calltime;
 238         ktime_t                 rettime;
 239 };
 240
 241 #ifdef CONFIG_BOOT_TRACER
 242 extern void trace_boot(struct boot_trace *it, initcall_t fn);
 243 extern void start_boot_trace(void);
 244 extern void stop_boot_trace(void);
 245 #else
 246 static inline void trace_boot(struct boot_trace *it, initcall_t fn) { }
 247 static inline void start_boot_trace(void) { }
 248 static inline void stop_boot_trace(void) { }
 249 #endif
 250
 251
 252
 253 #endif /* _LINUX_FTRACE_H */