sys/sys/ktr.h

   1 /*
   2  * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 /*
  35  * Generic Kernel trace buffer support.
  36  *
  37  */
  38
  39 #ifndef _SYS_KTR_H_
  40 #define _SYS_KTR_H_
  41
  42 #include <sys/types.h>
  43 #include <sys/sysctl.h>
  44 #include <sys/cpputil.h>
  45
  46 #ifdef _KERNEL
  47 #include "opt_ktr.h"
  48 #endif
  49
  50 /*
  51  * Conveniently auto-enable KTRs when particular KTRs are specified
  52  * in kernel options.  This way we can get logging during boot.
  53  * However, if KTR_ALL is optioned, just disable everything by default.
  54  * The user can enable individual masks via sysctl.
  55  */
  56 #if defined(KTR_ALL)
  57 #define KTR_AUTO_ENABLE         0
  58 #else
  59 #define KTR_ALL                 0
  60 #define KTR_AUTO_ENABLE         -1
  61 #endif
  62
  63 #define KTR_BUFSIZE             192
  64 #define KTR_VERSION             4
  65
  66 #define KTR_VERSION_WITH_FREQ   3
  67 #define KTR_VERSION_KTR_CPU     4
  68
  69 #ifndef LOCORE
  70
  71 struct ktr_info {
  72         const char *kf_name;    /* human-interpreted subsystem name */
  73         int32_t *kf_master_enable; /* the master enable variable */
  74         const char * const kf_format;   /* data format */
  75         int kf_data_size;       /* relevance of the data buffer */
  76 };
  77
  78 struct ktr_entry {
  79         u_int64_t ktr_timestamp;
  80         struct ktr_info *ktr_info;
  81         const   char *ktr_file;
  82         void    *ktr_caller1;
  83         void    *ktr_caller2;
  84         int32_t ktr_line;
  85         int32_t ktr_unused;
  86         int32_t ktr_data[KTR_BUFSIZE / sizeof(int32_t)];
  87 };
  88
  89 struct ktr_cpu_core {
  90         struct ktr_entry *ktr_buf;
  91         int              ktr_idx;
  92 };
  93
  94 struct ktr_cpu {
  95         struct ktr_cpu_core core;
  96 } __cachealign;
  97
  98 #ifdef _KERNEL
  99
 100 struct ktr_entry * ktr_begin_write_entry(struct ktr_info *,
 101                                          const char *, int);
 102 int ktr_finish_write_entry(struct ktr_info *, struct ktr_entry *);
 103 void    cpu_ktr_caller(struct ktr_entry *ktr);
 104
 105 #endif
 106
 107 /*
 108  * Take advantage of constant integer optimizations by the compiler
 109  * to optimize-out disabled code at compile-time.  If KTR_ENABLE_<name>
 110  * is 0, the compiler avoids generating all related code when KTR is enabled.
 111  */
 112
 113 #ifdef KTR
 114
 115 SYSCTL_DECL(_debug_ktr);
 116
 117 #define KTR_INFO_MASTER(master)                                             \
 118             SYSCTL_NODE(_debug_ktr, OID_AUTO, master, CTLFLAG_RW, 0, "");   \
 119             int ktr_ ## master ## _enable = KTR_AUTO_ENABLE;                \
 120             SYSCTL_INT(_debug_ktr, OID_AUTO, master ## _enable, CTLFLAG_RW, \
 121                 &ktr_ ## master ## _enable, 0,                              \
 122                 "Bit mask to control " __XSTRING(master) "'s event logging")
 123
 124 #define KTR_INFO_MASTER_EXTERN(master)                                  \
 125             SYSCTL_DECL(_debug_ktr_ ## master);                         \
 126             extern int ktr_ ## master ## _enable                        \
 127
 128 /*
 129  * This creates a read-only sysctl so the user knows what the mask
 130  * definitions are and a number of static const int's which are used
 131  * by the compiler to optimize the trace logging at compile-time and
 132  * run-time.
 133  * You're supposed to specify any arguments to the format as you would in
 134  * a function prototype.
 135  * We automagically create a struct for the arguments and a throwaway
 136  * function that will be called with the format and the actual arguments
 137  * at the KTR_LOG site. This makes sure that the compiler will typecheck
 138  * the arguments against the format string. On gcc, this requires -Wformat
 139  * (which is included in -Wall) and -O1 at least. Note that using
 140  * ktr_info.kf_format will not work, hence we need to define another
 141  * throwaway const wariable for the format.
 142  */
 143 #define KTR_INFO(compile, master, name, maskbit, format, ...)           \
 144         static const int ktr_ ## master ## _ ## name ## _mask =         \
 145                 1 << (maskbit);                                         \
 146         static const int ktr_ ## master ## _ ##name ## _enable =        \
 147                 compile;                                                \
 148         static int ktr_ ## master ## _ ## name ## _mask_ro =            \
 149                 1 << (maskbit);                                         \
 150         SYSCTL_INT(_debug_ktr_ ## master, OID_AUTO, name ## _mask,      \
 151                    CTLFLAG_RD, &ktr_ ## master ## _ ## name ## _mask_ro, \
 152                    0, "Value of the " __XSTRING(name) " event in " __XSTRING(master) "'s mask"); \
 153         __GENSTRUCT(ktr_info_ ## master ## _ ## name ## _args, __VA_ARGS__) \
 154                 __packed;                                               \
 155         CTASSERT(sizeof(struct ktr_info_ ## master ## _ ## name ## _args) <= KTR_BUFSIZE); \
 156         static inline void                                              \
 157         __ktr_info_ ## master ## _ ## name ## _fmtcheck(const char *fmt, \
 158                                                         ...) __printf0like(1, 2); \
 159         static inline void                                              \
 160         __ktr_info_ ## master ## _ ## name ## _fmtcheck(const char *fmt __unused, \
 161                                                         ...)            \
 162         {}                                                              \
 163         static const char * const __ktr_ ## master ## _ ## name ## _fmt = format; \
 164         static struct ktr_info ktr_info_ ## master ## _ ## name = {     \
 165                 .kf_name = #master "_" #name,                           \
 166                 .kf_master_enable = &ktr_ ## master ## _enable,         \
 167                 .kf_format = format,                                    \
 168                 .kf_data_size = sizeof(struct ktr_info_ ## master ## _ ## name ## _args), \
 169         }
 170
 171
 172
 173
 174 /*
 175  * Call ktr_begin_write_entry() that sets up the entry for us; use
 176  * a struct copy to give as max flexibility as possible to the compiler.
 177  * In higher optimization levels, it will copy the arguments directly from
 178  * registers to the destination buffer. Call our dummy function that will
 179  * typecheck the arguments against the format string.
 180  */
 181 #define KTR_LOG(name, ...)                                              \
 182         do {                                                            \
 183                 __ktr_info_ ## name ## _fmtcheck (__ktr_ ## name ## _fmt, ##__VA_ARGS__);       \
 184                 if (ktr_ ## name ## _enable &&                          \
 185                     (ktr_ ## name ## _mask & *ktr_info_ ## name .kf_master_enable)) { \
 186                         struct ktr_entry *entry;                        \
 187                         entry = ktr_begin_write_entry(&ktr_info_ ## name, __FILE__, __LINE__); \
 188                         if (!entry)                                     \
 189                                 break;                                  \
 190                         *(struct ktr_info_  ## name ## _args *)&entry->ktr_data[0] = \
 191                                 (struct ktr_info_  ## name ## _args){ __VA_ARGS__}; \
 192                         if (ktr_finish_write_entry(&ktr_info_ ## name, entry)) { \
 193                                 kprintf(ktr_info_ ## name .kf_format, ##__VA_ARGS__); \
 194                                 kprintf("\n");                          \
 195                         }                                               \
 196                 }                                                       \
 197         }  while(0)
 198
 199 #define KTR_COND_LOG(name, cond, ...)                                   \
 200         do {                                                            \
 201                 __ktr_info_ ## name ## _fmtcheck (__ktr_ ## name ## _fmt, ##__VA_ARGS__);       \
 202                 if ((cond) &&                                           \
 203                     ktr_ ## name ## _enable &&                          \
 204                     (ktr_ ## name ## _mask & *ktr_info_ ## name .kf_master_enable)) { \
 205                         struct ktr_entry *entry;                        \
 206                         entry = ktr_begin_write_entry(&ktr_info_ ## name, __FILE__, __LINE__); \
 207                         if (!entry)                                     \
 208                                 break;                                  \
 209                         *(struct ktr_info_  ## name ## _args *)&entry->ktr_data[0] = \
 210                                 (struct ktr_info_  ## name ## _args){ __VA_ARGS__}; \
 211                         if (ktr_finish_write_entry(&ktr_info_ ## name, entry)) { \
 212                                 kprintf(ktr_info_ ## name .kf_format, ##__VA_ARGS__); \
 213                                 kprintf("\n");                          \
 214                         }                                               \
 215                 }                                                       \
 216         }  while(0)
 217
 218 #else
 219
 220 #define KTR_INFO_MASTER(master)                                         \
 221             static const int ktr_ ## master ## _enable = 0
 222
 223 #define KTR_INFO_MASTER_EXTERN(master)                                  \
 224             static const int ktr_ ## master ## _enable
 225
 226 #define KTR_INFO(compile, master, name, maskbit, format, ...)           \
 227             static const int ktr_ ## master ## _ ## name ## _mask =     \
 228                     (1 << maskbit)
 229
 230 #define KTR_LOG(info, args...)
 231
 232 #define KTR_COND_LOG(info, args...)
 233
 234 #endif
 235
 236 #endif /* !LOCORE */
 237 #endif /* !_SYS_KTR_H_ */