LXR linux/kernel/trace/trace

   1/*
   2 * Common header file for probe-based Dynamic events.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program; if not, write to the Free Software
  15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16 *
  17 * This code was copied from kernel/trace/trace_kprobe.h written by
  18 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
  19 *
  20 * Updates to make this generic:
  21 * Copyright (C) IBM Corporation, 2010-2011
  22 * Author:     Srikar Dronamraju
  23 */
  24
  25#include <linux/seq_file.h>
  26#include <linux/slab.h>
  27#include <linux/smp.h>
  28#include <linux/debugfs.h>
  29#include <linux/types.h>
  30#include <linux/string.h>
  31#include <linux/ctype.h>
  32#include <linux/ptrace.h>
  33#include <linux/perf_event.h>
  34#include <linux/kprobes.h>
  35#include <linux/stringify.h>
  36#include <linux/limits.h>
  37#include <linux/uaccess.h>
  38#include <asm/bitsperlong.h>
  39
  40#include "trace.h"
  41#include "trace_output.h"
  42
  43#define MAX_TRACE_ARGS          128
  44#define MAX_ARGSTR_LEN          63
  45#define MAX_EVENT_NAME_LEN      64
  46#define MAX_STRING_SIZE         PATH_MAX
  47
  48/* Reserved field names */
  49#define FIELD_STRING_IP         "__probe_ip"
  50#define FIELD_STRING_RETIP      "__probe_ret_ip"
  51#define FIELD_STRING_FUNC       "__probe_func"
  52
  53#undef DEFINE_FIELD
  54#define DEFINE_FIELD(type, item, name, is_signed)                       \
  55        do {                                                            \
  56                ret = trace_define_field(event_call, #type, name,       \
  57                                         offsetof(typeof(field), item), \
  58                                         sizeof(field.item), is_signed, \
  59                                         FILTER_OTHER);                 \
  60                if (ret)                                                \
  61                        return ret;                                     \
  62        } while (0)
  63
  64
  65/* Flags for trace_probe */
  66#define TP_FLAG_TRACE           1
  67#define TP_FLAG_PROFILE         2
  68#define TP_FLAG_REGISTERED      4
  69
  70
  71/* data_rloc: data relative location, compatible with u32 */
  72#define make_data_rloc(len, roffs)      \
  73        (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
  74#define get_rloc_len(dl)                ((u32)(dl) >> 16)
  75#define get_rloc_offs(dl)               ((u32)(dl) & 0xffff)
  76
  77/*
  78 * Convert data_rloc to data_loc:
  79 *  data_rloc stores the offset from data_rloc itself, but data_loc
  80 *  stores the offset from event entry.
  81 */
  82#define convert_rloc_to_loc(dl, offs)   ((u32)(dl) + (offs))
  83
  84static inline void *get_rloc_data(u32 *dl)
  85{
  86        return (u8 *)dl + get_rloc_offs(*dl);
  87}
  88
  89/* For data_loc conversion */
  90static inline void *get_loc_data(u32 *dl, void *ent)
  91{
  92        return (u8 *)ent + get_rloc_offs(*dl);
  93}
  94
  95/* Data fetch function type */
  96typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
  97/* Printing function type */
  98typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
  99
 100/* Fetch types */
 101enum {
 102        FETCH_MTD_reg = 0,
 103        FETCH_MTD_stack,
 104        FETCH_MTD_retval,
 105        FETCH_MTD_memory,
 106        FETCH_MTD_symbol,
 107        FETCH_MTD_deref,
 108        FETCH_MTD_bitfield,
 109        FETCH_MTD_file_offset,
 110        FETCH_MTD_END,
 111};
 112
 113/* Fetch type information table */
 114struct fetch_type {
 115        const char              *name;          /* Name of type */
 116        size_t                  size;           /* Byte size of type */
 117        int                     is_signed;      /* Signed flag */
 118        print_type_func_t       print;          /* Print functions */
 119        const char              *fmt;           /* Fromat string */
 120        const char              *fmttype;       /* Name in format file */
 121        /* Fetch functions */
 122        fetch_func_t            fetch[FETCH_MTD_END];
 123};
 124
 125struct fetch_param {
 126        fetch_func_t            fn;
 127        void                    *data;
 128};
 129
 130/* For defining macros, define string/string_size types */
 131typedef u32 string;
 132typedef u32 string_size;
 133
 134#define PRINT_TYPE_FUNC_NAME(type)      print_type_##type
 135#define PRINT_TYPE_FMT_NAME(type)       print_type_format_##type
 136
 137/* Printing  in basic type function template */
 138#define DECLARE_BASIC_PRINT_TYPE_FUNC(type)                             \
 139__kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s,           \
 140                                         const char *name,              \
 141                                         void *data, void *ent);        \
 142extern const char PRINT_TYPE_FMT_NAME(type)[]
 143
 144DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
 145DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
 146DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
 147DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
 148DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
 149DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
 150DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
 151DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
 152DECLARE_BASIC_PRINT_TYPE_FUNC(string);
 153
 154#define FETCH_FUNC_NAME(method, type)   fetch_##method##_##type
 155
 156/* Declare macro for basic types */
 157#define DECLARE_FETCH_FUNC(method, type)                                \
 158extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs,         \
 159                                          void *data, void *dest)
 160
 161#define DECLARE_BASIC_FETCH_FUNCS(method)       \
 162DECLARE_FETCH_FUNC(method, u8);                 \
 163DECLARE_FETCH_FUNC(method, u16);                \
 164DECLARE_FETCH_FUNC(method, u32);                \
 165DECLARE_FETCH_FUNC(method, u64)
 166
 167DECLARE_BASIC_FETCH_FUNCS(reg);
 168#define fetch_reg_string                        NULL
 169#define fetch_reg_string_size                   NULL
 170
 171DECLARE_BASIC_FETCH_FUNCS(retval);
 172#define fetch_retval_string                     NULL
 173#define fetch_retval_string_size                NULL
 174
 175DECLARE_BASIC_FETCH_FUNCS(symbol);
 176DECLARE_FETCH_FUNC(symbol, string);
 177DECLARE_FETCH_FUNC(symbol, string_size);
 178
 179DECLARE_BASIC_FETCH_FUNCS(deref);
 180DECLARE_FETCH_FUNC(deref, string);
 181DECLARE_FETCH_FUNC(deref, string_size);
 182
 183DECLARE_BASIC_FETCH_FUNCS(bitfield);
 184#define fetch_bitfield_string                   NULL
 185#define fetch_bitfield_string_size              NULL
 186
 187/*
 188 * Define macro for basic types - we don't need to define s* types, because
 189 * we have to care only about bitwidth at recording time.
 190 */
 191#define DEFINE_BASIC_FETCH_FUNCS(method) \
 192DEFINE_FETCH_##method(u8)               \
 193DEFINE_FETCH_##method(u16)              \
 194DEFINE_FETCH_##method(u32)              \
 195DEFINE_FETCH_##method(u64)
 196
 197/* Default (unsigned long) fetch type */
 198#define __DEFAULT_FETCH_TYPE(t) u##t
 199#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
 200#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
 201#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
 202
 203#define ASSIGN_FETCH_FUNC(method, type) \
 204        [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
 205
 206#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
 207        {.name = _name,                         \
 208         .size = _size,                                 \
 209         .is_signed = sign,                             \
 210         .print = PRINT_TYPE_FUNC_NAME(ptype),          \
 211         .fmt = PRINT_TYPE_FMT_NAME(ptype),             \
 212         .fmttype = _fmttype,                           \
 213         .fetch = {                                     \
 214ASSIGN_FETCH_FUNC(reg, ftype),                          \
 215ASSIGN_FETCH_FUNC(stack, ftype),                        \
 216ASSIGN_FETCH_FUNC(retval, ftype),                       \
 217ASSIGN_FETCH_FUNC(memory, ftype),                       \
 218ASSIGN_FETCH_FUNC(symbol, ftype),                       \
 219ASSIGN_FETCH_FUNC(deref, ftype),                        \
 220ASSIGN_FETCH_FUNC(bitfield, ftype),                     \
 221ASSIGN_FETCH_FUNC(file_offset, ftype),                  \
 222          }                                             \
 223        }
 224
 225#define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                   \
 226        __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
 227
 228#define ASSIGN_FETCH_TYPE_END {}
 229
 230#define FETCH_TYPE_STRING       0
 231#define FETCH_TYPE_STRSIZE      1
 232
 233/*
 234 * Fetch type information table.
 235 * It's declared as a weak symbol due to conditional compilation.
 236 */
 237extern __weak const struct fetch_type kprobes_fetch_type_table[];
 238extern __weak const struct fetch_type uprobes_fetch_type_table[];
 239
 240#ifdef CONFIG_KPROBE_EVENT
 241struct symbol_cache;
 242unsigned long update_symbol_cache(struct symbol_cache *sc);
 243void free_symbol_cache(struct symbol_cache *sc);
 244struct symbol_cache *alloc_symbol_cache(const char *sym, long offset);
 245#else
 246struct symbol_cache {
 247};
 248static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc)
 249{
 250        return 0;
 251}
 252
 253static inline void __used free_symbol_cache(struct symbol_cache *sc)
 254{
 255}
 256
 257static inline struct symbol_cache * __used
 258alloc_symbol_cache(const char *sym, long offset)
 259{
 260        return NULL;
 261}
 262#endif /* CONFIG_KPROBE_EVENT */
 263
 264struct probe_arg {
 265        struct fetch_param      fetch;
 266        struct fetch_param      fetch_size;
 267        unsigned int            offset; /* Offset from argument entry */
 268        const char              *name;  /* Name of this argument */
 269        const char              *comm;  /* Command of this argument */
 270        const struct fetch_type *type;  /* Type of this argument */
 271};
 272
 273static inline __kprobes void call_fetch(struct fetch_param *fprm,
 274                                 struct pt_regs *regs, void *dest)
 275{
 276        return fprm->fn(regs, fprm->data, dest);
 277}
 278
 279/* Check the name is good for event/group/fields */
 280static inline int is_good_name(const char *name)
 281{
 282        if (!isalpha(*name) && *name != '_')
 283                return 0;
 284        while (*++name != '\0') {
 285                if (!isalpha(*name) && !isdigit(*name) && *name != '_')
 286                        return 0;
 287        }
 288        return 1;
 289}
 290
 291extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
 292                   struct probe_arg *parg, bool is_return, bool is_kprobe);
 293
 294extern int traceprobe_conflict_field_name(const char *name,
 295                               struct probe_arg *args, int narg);
 296
 297extern void traceprobe_update_arg(struct probe_arg *arg);
 298extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 299
 300extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
 301
 302extern ssize_t traceprobe_probes_write(struct file *file,
 303                const char __user *buffer, size_t count, loff_t *ppos,
 304                int (*createfn)(int, char**));
 305
 306extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));
 307