kernel/trace/trace_probe.h

   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 */
  86 typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
  87 /* Printing function type */
  88 typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
  89
  90 /* Fetch types */
  91 enum {
  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 */
 103 struct 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
 114 struct fetch_param {
 115         fetch_func_t            fn;
 116         void                    *data;
 117 };
 118
 119 struct 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
 128 static 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 */
 135 static 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
 146 extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
 147                    struct probe_arg *parg, bool is_return, bool is_kprobe);
 148
 149 extern int traceprobe_conflict_field_name(const char *name,
 150                                struct probe_arg *args, int narg);
 151
 152 extern void traceprobe_update_arg(struct probe_arg *arg);
 153 extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 154
 155 extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
 156
 157 extern 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
 161 extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));