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**));