1 /* $OpenBSD: bt_parser.h,v 1.10 2020/09/14 18:45:19 jasper Exp $ */ 2 3 /* 4 * Copyright (c) 2019-2020 Martin Pieuchot <mpi@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #ifndef BT_PARSER_H 20 #define BT_PARSER_H 21 22 #ifndef nitems 23 #define nitems(_a) (sizeof((_a)) / sizeof((_a)[0])) 24 #endif 25 26 /* 27 * Probes represent entry points where events can be recorded. 28 * 29 * Those specified in a given bt(5) script are enabled at runtime. They 30 * are represented as: 31 * 32 * "provider:function:name" 33 * or 34 * "provider:time_unit:rate" 35 */ 36 struct bt_probe { 37 const char *bp_prov; /* provider */ 38 const char *bp_func; /* function or time unit */ 39 const char *bp_name; 40 uint32_t bp_rate; 41 #define bp_unit bp_func 42 }; 43 44 /* 45 * Filters correspond to predicates performed in kernel. 46 * 47 * When a probe fires the check is performed, if it isn't true no event 48 * is recorded. 49 */ 50 struct bt_filter { 51 enum bt_operand { 52 B_OP_NONE = 1, 53 B_OP_EQ, 54 B_OP_NE, 55 } bf_op; 56 enum bt_filtervar { 57 B_FV_NONE = 1, 58 B_FV_PID, 59 B_FV_TID 60 } bf_var; 61 uint32_t bf_val; 62 }; 63 64 TAILQ_HEAD(bt_ruleq, bt_rule); 65 66 /* 67 * A rule is the language representation of which 'action' to attach to 68 * which 'probe' under which conditions ('filter'). In other words it 69 * represents the following: 70 * 71 * probe / filter / { action } 72 */ 73 struct bt_rule { 74 TAILQ_ENTRY(bt_rule) br_next; /* linkage in global list */ 75 struct bt_probe *br_probe; 76 struct bt_filter *br_filter; 77 SLIST_HEAD(, bt_stmt) br_action; 78 79 enum bt_rtype { 80 B_RT_BEGIN = 1, 81 B_RT_END, 82 B_RT_PROBE, 83 } br_type; /* BEGIN, END or 'probe' */ 84 85 uint32_t br_pbn; /* ID assigned by the kernel */ 86 void *br_cookie; 87 }; 88 89 /* 90 * Global variable representation. 91 * 92 * Variables are untyped and also include maps and histograms. 93 */ 94 struct bt_var { 95 SLIST_ENTRY(bt_var) bv_next; /* linkage in global list */ 96 const char *bv_name; /* name of the variable */ 97 struct bt_arg *bv_value; /* corresponding value */ 98 }; 99 100 /* 101 * Respresentation of an argument. 102 * 103 * A so called "argument" can be any symbol representing a value or 104 * a combination of those through an operation. 105 */ 106 struct bt_arg { 107 SLIST_ENTRY(bt_arg) ba_next; 108 void *ba_value; 109 struct bt_arg *ba_key; /* key for maps/histograms */ 110 enum bt_argtype { 111 B_AT_STR = 1, /* C-style string */ 112 B_AT_LONG, /* Number (integer) */ 113 B_AT_VAR, /* global variable (@var) */ 114 B_AT_MAP, /* global map (@map[]) */ 115 B_AT_HIST, /* histogram */ 116 117 B_AT_BI_PID, 118 B_AT_BI_TID, 119 B_AT_BI_COMM, 120 B_AT_BI_CPU, 121 B_AT_BI_NSECS, 122 B_AT_BI_KSTACK, 123 B_AT_BI_USTACK, 124 B_AT_BI_ARG0, 125 B_AT_BI_ARG1, 126 B_AT_BI_ARG2, 127 B_AT_BI_ARG3, 128 B_AT_BI_ARG4, 129 B_AT_BI_ARG5, 130 B_AT_BI_ARG6, 131 B_AT_BI_ARG7, 132 B_AT_BI_ARG8, 133 B_AT_BI_ARG9, 134 B_AT_BI_ARGS, 135 B_AT_BI_RETVAL, 136 137 B_AT_MF_COUNT, /* @map[key] = count() */ 138 B_AT_MF_MAX, /* @map[key] = max(nsecs) */ 139 B_AT_MF_MIN, /* @map[key] = min(pid) */ 140 B_AT_MF_SUM, /* @map[key] = sum(@elapsed) */ 141 142 B_AT_OP_ADD, 143 B_AT_OP_MINUS, 144 B_AT_OP_MULT, 145 B_AT_OP_DIVIDE, 146 B_AT_OP_AND, 147 B_AT_OP_OR, 148 } ba_type; 149 }; 150 151 #define BA_INITIALIZER(v, t) { { NULL }, (void *)(v), NULL, (t) } 152 153 /* 154 * Each action associated with a given probe is made of at least one 155 * statement. 156 * 157 * Statements are interpreted linearly in userland to format data 158 * recorded in the form of events. 159 */ 160 struct bt_stmt { 161 SLIST_ENTRY(bt_stmt) bs_next; 162 struct bt_var *bs_var; /* for STOREs */ 163 SLIST_HEAD(, bt_arg) bs_args; 164 enum bt_action { 165 B_AC_BUCKETIZE, /* @h = hist(42) */ 166 B_AC_CLEAR, /* clear(@map) */ 167 B_AC_DELETE, /* delete(@map[key]) */ 168 B_AC_EXIT, /* exit() */ 169 B_AC_INSERT, /* @map[key] = 42 */ 170 B_AC_PRINT, /* print(@map, 10) */ 171 B_AC_PRINTF, /* printf("hello!\n") */ 172 B_AC_STORE, /* @a = 3 */ 173 B_AC_TIME, /* time("%H:%M:%S ") */ 174 B_AC_ZERO, /* zero(@map) */ 175 } bs_act; 176 }; 177 178 struct bt_ruleq g_rules; /* Successfully parsed rules. */ 179 int g_nprobes; /* # of probes to attach */ 180 181 int btparse(const char *, size_t, const char *, int); 182 183 #define ba_new(v, t) ba_new0((void *)(v), (t)) 184 struct bt_arg *ba_new0(void *, enum bt_argtype); 185 186 const char *bv_name(struct bt_var *); 187 188 void bm_insert(struct bt_var *, struct bt_arg *, 189 struct bt_arg *); 190 191 #endif /* BT_PARSER_H */ 192