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#define TP_FLAG_UPROBE          8
  70
  71
  72/* data_rloc: data relative location, compatible with u32 */
  73#define make_data_rloc(len, roffs)      \
  74        (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
  75#define get_rloc_len(dl)                ((u32)(dl) >> 16)
  76#define get_rloc_offs(dl)               ((u32)(dl) & 0xffff)
  77
  78/*
  79 * Convert data_rloc to data_loc:
  80 *  data_rloc stores the offset from data_rloc itself, but data_loc
  81 *  stores the offset from event entry.
  82 */
  83#define convert_rloc_to_loc(dl, offs)   ((u32)(dl) + (offs))
  84
  85/* Data fetch function type */
  86typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
  87/* Printing function type */
  88typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
  89
  90/* Fetch types */
  91enum {
  92        FETCH_MTD_reg = 0,
  93        FETCH_MTD_stack,
  94        FETCH_MTD_retval,
  95        FETCH_MTD_memory,
  96        FETCH_MTD_symbol,
  97        FETCH_MTD_deref,
  98        FETCH_MTD_bitfield,
  99        FETCH_MTD_END,
 100};
 101
 102/* Fetch type information table */
 103struct fetch_type {
 104        const char              *name;          /* Name of type */
 105        size_t                  size;           /* Byte size of type */
 106        int                     is_signed;      /* Signed flag */
 107        print_type_func_t       print;          /* Print functions */
 108        const char              *fmt;           /* Fromat string */
 109        const char              *fmttype;       /* Name in format file */
 110        /* Fetch functions */
 111        fetch_func_t            fetch[FETCH_MTD_END];
 112};
 113
 114struct fetch_param {
 115        fetch_func_t            fn;
 116        void                    *data;
 117};
 118
 119struct probe_arg {
 120        struct fetch_param      fetch;
 121        struct fetch_param      fetch_size;
 122        unsigned int            offset; /* Offset from argument entry */
 123        const char              *name;  /* Name of this argument */
 124        const char              *comm;  /* Command of this argument */
 125        const struct fetch_type *type;  /* Type of this argument */
 126};
 127
 128static inline __kprobes void call_fetch(struct fetch_param *fprm,
 129                                 struct pt_regs *regs, void *dest)
 130{
 131        return fprm->fn(regs, fprm->data, dest);
 132}
 133
 134/* Check the name is good for event/group/fields */
 135static inline int is_good_name(const char *name)
 136{
 137        if (!isalpha(*name) && *name != '_')
 138                return 0;
 139        while (*++name != '\0') {
 140                if (!isalpha(*name) && !isdigit(*name) && *name != '_')
 141                        return 0;
 142        }
 143        return 1;
 144}
 145
 146extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
 147                   struct probe_arg *parg, bool is_return, bool is_kprobe);
 148
 149extern int traceprobe_conflict_field_name(const char *name,
 150                               struct probe_arg *args, int narg);
 151
 152extern void traceprobe_update_arg(struct probe_arg *arg);
 153extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 154
 155extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
 156
 157extern ssize_t traceprobe_probes_write(struct file *file,
 158                const char __user *buffer, size_t count, loff_t *ppos,
 159                int (*createfn)(int, char**));
 160
 161extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));
 162