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