1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Common header file for probe-based Dynamic events. 4 * 5 * This code was copied from kernel/trace/trace_kprobe.h written by 6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> 7 * 8 * Updates to make this generic: 9 * Copyright (C) IBM Corporation, 2010-2011 10 * Author: Srikar Dronamraju 11 */ 12 13 #include <linux/seq_file.h> 14 #include <linux/slab.h> 15 #include <linux/smp.h> 16 #include <linux/tracefs.h> 17 #include <linux/types.h> 18 #include <linux/string.h> 19 #include <linux/ctype.h> 20 #include <linux/ptrace.h> 21 #include <linux/perf_event.h> 22 #include <linux/kprobes.h> 23 #include <linux/stringify.h> 24 #include <linux/limits.h> 25 #include <linux/uaccess.h> 26 #include <linux/bitops.h> 27 #include <asm/bitsperlong.h> 28 29 #include "trace.h" 30 #include "trace_output.h" 31 32 #define MAX_TRACE_ARGS 128 33 #define MAX_ARGSTR_LEN 63 34 #define MAX_ARRAY_LEN 64 35 #define MAX_STRING_SIZE PATH_MAX 36 37 /* Reserved field names */ 38 #define FIELD_STRING_IP "__probe_ip" 39 #define FIELD_STRING_RETIP "__probe_ret_ip" 40 #define FIELD_STRING_FUNC "__probe_func" 41 42 #undef DEFINE_FIELD 43 #define DEFINE_FIELD(type, item, name, is_signed) \ 44 do { \ 45 ret = trace_define_field(event_call, #type, name, \ 46 offsetof(typeof(field), item), \ 47 sizeof(field.item), is_signed, \ 48 FILTER_OTHER); \ 49 if (ret) \ 50 return ret; \ 51 } while (0) 52 53 54 /* Flags for trace_probe */ 55 #define TP_FLAG_TRACE 1 56 #define TP_FLAG_PROFILE 2 57 #define TP_FLAG_REGISTERED 4 58 59 /* data_loc: data location, compatible with u32 */ 60 #define make_data_loc(len, offs) \ 61 (((u32)(len) << 16) | ((u32)(offs) & 0xffff)) 62 #define get_loc_len(dl) ((u32)(dl) >> 16) 63 #define get_loc_offs(dl) ((u32)(dl) & 0xffff) 64 65 static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) 66 { 67 return (u8 *)ent + get_loc_offs(*dl); 68 } 69 70 static nokprobe_inline u32 update_data_loc(u32 loc, int consumed) 71 { 72 u32 maxlen = get_loc_len(loc); 73 u32 offset = get_loc_offs(loc); 74 75 return make_data_loc(maxlen - consumed, offset + consumed); 76 } 77 78 /* Printing function type */ 79 typedef int (*print_type_func_t)(struct trace_seq *, void *, void *); 80 81 enum fetch_op { 82 FETCH_OP_NOP = 0, 83 // Stage 1 (load) ops 84 FETCH_OP_REG, /* Register : .param = offset */ 85 FETCH_OP_STACK, /* Stack : .param = index */ 86 FETCH_OP_STACKP, /* Stack pointer */ 87 FETCH_OP_RETVAL, /* Return value */ 88 FETCH_OP_IMM, /* Immediate : .immediate */ 89 FETCH_OP_COMM, /* Current comm */ 90 FETCH_OP_ARG, /* Function argument : .param */ 91 FETCH_OP_FOFFS, /* File offset: .immediate */ 92 // Stage 2 (dereference) op 93 FETCH_OP_DEREF, /* Dereference: .offset */ 94 // Stage 3 (store) ops 95 FETCH_OP_ST_RAW, /* Raw: .size */ 96 FETCH_OP_ST_MEM, /* Mem: .offset, .size */ 97 FETCH_OP_ST_STRING, /* String: .offset, .size */ 98 // Stage 4 (modify) op 99 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ 100 // Stage 5 (loop) op 101 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */ 102 FETCH_OP_END, 103 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */ 104 }; 105 106 struct fetch_insn { 107 enum fetch_op op; 108 union { 109 unsigned int param; 110 struct { 111 unsigned int size; 112 int offset; 113 }; 114 struct { 115 unsigned char basesize; 116 unsigned char lshift; 117 unsigned char rshift; 118 }; 119 unsigned long immediate; 120 void *data; 121 }; 122 }; 123 124 /* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ 125 #define FETCH_INSN_MAX 16 126 127 /* Fetch type information table */ 128 struct fetch_type { 129 const char *name; /* Name of type */ 130 size_t size; /* Byte size of type */ 131 int is_signed; /* Signed flag */ 132 print_type_func_t print; /* Print functions */ 133 const char *fmt; /* Fromat string */ 134 const char *fmttype; /* Name in format file */ 135 }; 136 137 /* For defining macros, define string/string_size types */ 138 typedef u32 string; 139 typedef u32 string_size; 140 141 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 142 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 143 144 /* Printing in basic type function template */ 145 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ 146 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\ 147 extern const char PRINT_TYPE_FMT_NAME(type)[] 148 149 DECLARE_BASIC_PRINT_TYPE_FUNC(u8); 150 DECLARE_BASIC_PRINT_TYPE_FUNC(u16); 151 DECLARE_BASIC_PRINT_TYPE_FUNC(u32); 152 DECLARE_BASIC_PRINT_TYPE_FUNC(u64); 153 DECLARE_BASIC_PRINT_TYPE_FUNC(s8); 154 DECLARE_BASIC_PRINT_TYPE_FUNC(s16); 155 DECLARE_BASIC_PRINT_TYPE_FUNC(s32); 156 DECLARE_BASIC_PRINT_TYPE_FUNC(s64); 157 DECLARE_BASIC_PRINT_TYPE_FUNC(x8); 158 DECLARE_BASIC_PRINT_TYPE_FUNC(x16); 159 DECLARE_BASIC_PRINT_TYPE_FUNC(x32); 160 DECLARE_BASIC_PRINT_TYPE_FUNC(x64); 161 162 DECLARE_BASIC_PRINT_TYPE_FUNC(string); 163 DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); 164 165 /* Default (unsigned long) fetch type */ 166 #define __DEFAULT_FETCH_TYPE(t) x##t 167 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 168 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 169 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 170 171 #define __ADDR_FETCH_TYPE(t) u##t 172 #define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t) 173 #define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG) 174 175 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 176 {.name = _name, \ 177 .size = _size, \ 178 .is_signed = sign, \ 179 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 180 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 181 .fmttype = _fmttype, \ 182 } 183 #define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 184 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype) 185 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 186 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype) 187 188 /* If ptype is an alias of atype, use this macro (show atype in format) */ 189 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ 190 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype) 191 192 #define ASSIGN_FETCH_TYPE_END {} 193 #define MAX_ARRAY_LEN 64 194 195 #ifdef CONFIG_KPROBE_EVENTS 196 bool trace_kprobe_on_func_entry(struct trace_event_call *call); 197 bool trace_kprobe_error_injectable(struct trace_event_call *call); 198 #else 199 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) 200 { 201 return false; 202 } 203 204 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) 205 { 206 return false; 207 } 208 #endif /* CONFIG_KPROBE_EVENTS */ 209 210 struct probe_arg { 211 struct fetch_insn *code; 212 bool dynamic;/* Dynamic array (string) is used */ 213 unsigned int offset; /* Offset from argument entry */ 214 unsigned int count; /* Array count */ 215 const char *name; /* Name of this argument */ 216 const char *comm; /* Command of this argument */ 217 char *fmt; /* Format string if needed */ 218 const struct fetch_type *type; /* Type of this argument */ 219 }; 220 221 struct trace_probe { 222 unsigned int flags; /* For TP_FLAG_* */ 223 struct trace_event_class class; 224 struct trace_event_call call; 225 struct list_head files; 226 ssize_t size; /* trace entry size */ 227 unsigned int nr_args; 228 struct probe_arg args[]; 229 }; 230 231 struct event_file_link { 232 struct trace_event_file *file; 233 struct list_head list; 234 }; 235 236 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 237 { 238 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); 239 } 240 241 static inline bool trace_probe_is_registered(struct trace_probe *tp) 242 { 243 return !!(tp->flags & TP_FLAG_REGISTERED); 244 } 245 246 /* Check the name is good for event/group/fields */ 247 static inline bool is_good_name(const char *name) 248 { 249 if (!isalpha(*name) && *name != '_') 250 return false; 251 while (*++name != '\0') { 252 if (!isalpha(*name) && !isdigit(*name) && *name != '_') 253 return false; 254 } 255 return true; 256 } 257 258 static inline struct event_file_link * 259 find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) 260 { 261 struct event_file_link *link; 262 263 list_for_each_entry(link, &tp->files, list) 264 if (link->file == file) 265 return link; 266 267 return NULL; 268 } 269 270 #define TPARG_FL_RETURN BIT(0) 271 #define TPARG_FL_KERNEL BIT(1) 272 #define TPARG_FL_FENTRY BIT(2) 273 #define TPARG_FL_MASK GENMASK(2, 0) 274 275 extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, 276 struct probe_arg *parg, unsigned int flags); 277 278 extern int traceprobe_conflict_field_name(const char *name, 279 struct probe_arg *args, int narg); 280 281 extern int traceprobe_update_arg(struct probe_arg *arg); 282 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 283 284 extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 285 286 extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return); 287 288 #ifdef CONFIG_PERF_EVENTS 289 extern struct trace_event_call * 290 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 291 bool is_return); 292 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); 293 294 extern struct trace_event_call * 295 create_local_trace_uprobe(char *name, unsigned long offs, 296 unsigned long ref_ctr_offset, bool is_return); 297 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); 298 #endif 299 extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, 300 size_t offset, struct trace_probe *tp); 301