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**)); 162