[deliverable/linux.git] / kernel / trace / trace_probe.h

/*
 * Common header file for probe-based Dynamic events.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * This code was copied from kernel/trace/trace_kprobe.h written by
 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
 *
 * Updates to make this generic:
 * Copyright (C) IBM Corporation, 2010-2011
 * Author:     Srikar Dronamraju
 */

#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/debugfs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/ptrace.h>
#include <linux/perf_event.h>
#include <linux/kprobes.h>
#include <linux/stringify.h>
#include <linux/limits.h>
#include <linux/uaccess.h>
#include <asm/bitsperlong.h>

#include "trace.h"
#include "trace_output.h"

#define MAX_TRACE_ARGS		128
#define MAX_ARGSTR_LEN		63
#define MAX_EVENT_NAME_LEN	64
#define MAX_STRING_SIZE		PATH_MAX

/* Reserved field names */
#define FIELD_STRING_IP		"__probe_ip"
#define FIELD_STRING_RETIP	"__probe_ret_ip"
#define FIELD_STRING_FUNC	"__probe_func"

#undef DEFINE_FIELD
#define DEFINE_FIELD(type, item, name, is_signed)			\
	do {								\
		ret = trace_define_field(event_call, #type, name,	\
					 offsetof(typeof(field), item),	\
					 sizeof(field.item), is_signed, \
					 FILTER_OTHER);			\
		if (ret)						\
			return ret;					\
	} while (0)


/* Flags for trace_probe */
#define TP_FLAG_TRACE		1
#define TP_FLAG_PROFILE		2
#define TP_FLAG_REGISTERED	4


/* data_rloc: data relative location, compatible with u32 */
#define make_data_rloc(len, roffs)	\
	(((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
#define get_rloc_len(dl)		((u32)(dl) >> 16)
#define get_rloc_offs(dl)		((u32)(dl) & 0xffff)

/*
 * Convert data_rloc to data_loc:
 *  data_rloc stores the offset from data_rloc itself, but data_loc
 *  stores the offset from event entry.
 */
#define convert_rloc_to_loc(dl, offs)	((u32)(dl) + (offs))

/* Data fetch function type */
typedef	void (*fetch_func_t)(struct pt_regs *, void *, void *);
/* Printing function type */
typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);

/* Fetch types */
enum {
	FETCH_MTD_reg = 0,
	FETCH_MTD_stack,
	FETCH_MTD_retval,
	FETCH_MTD_memory,
	FETCH_MTD_symbol,
	FETCH_MTD_deref,
	FETCH_MTD_bitfield,
	FETCH_MTD_END,
};

/* Fetch type information table */
struct fetch_type {
	const char		*name;		/* Name of type */
	size_t			size;		/* Byte size of type */
	int			is_signed;	/* Signed flag */
	print_type_func_t	print;		/* Print functions */
	const char		*fmt;		/* Fromat string */
	const char		*fmttype;	/* Name in format file */
	/* Fetch functions */
	fetch_func_t		fetch[FETCH_MTD_END];
};

struct fetch_param {
	fetch_func_t		fn;
	void 			*data;
};

struct probe_arg {
	struct fetch_param	fetch;
	struct fetch_param	fetch_size;
	unsigned int		offset;	/* Offset from argument entry */
	const char		*name;	/* Name of this argument */
	const char		*comm;	/* Command of this argument */
	const struct fetch_type	*type;	/* Type of this argument */
};

struct trace_probe {
	unsigned int			flags;	/* For TP_FLAG_* */
	struct ftrace_event_class	class;
	struct ftrace_event_call	call;
	struct list_head 		files;
	ssize_t				size;	/* trace entry size */
	unsigned int			nr_args;
	struct probe_arg		args[];
};

static inline bool trace_probe_is_enabled(struct trace_probe *tp)
{
	return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
}

static inline bool trace_probe_is_registered(struct trace_probe *tp)
{
	return !!(tp->flags & TP_FLAG_REGISTERED);
}

static inline __kprobes void call_fetch(struct fetch_param *fprm,
				 struct pt_regs *regs, void *dest)
{
	return fprm->fn(regs, fprm->data, dest);
}

/* Check the name is good for event/group/fields */
static inline int is_good_name(const char *name)
{
	if (!isalpha(*name) && *name != '_')
		return 0;
	while (*++name != '\0') {
		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
			return 0;
	}
	return 1;
}

extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
		   struct probe_arg *parg, bool is_return, bool is_kprobe);

extern int traceprobe_conflict_field_name(const char *name,
			       struct probe_arg *args, int narg);

extern void traceprobe_update_arg(struct probe_arg *arg);
extern void traceprobe_free_probe_arg(struct probe_arg *arg);

extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);

extern ssize_t traceprobe_probes_write(struct file *file,
		const char __user *buffer, size_t count, loff_t *ppos,
		int (*createfn)(int, char**));

extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));

/* Sum up total data length for dynamic arraies (strings) */
static inline __kprobes int
__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
{
	int i, ret = 0;
	u32 len;

	for (i = 0; i < tp->nr_args; i++)
		if (unlikely(tp->args[i].fetch_size.fn)) {
			call_fetch(&tp->args[i].fetch_size, regs, &len);
			ret += len;
		}

	return ret;
}

/* Store the value of each argument */
static inline __kprobes void
store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
		 u8 *data, int maxlen)
{
	int i;
	u32 end = tp->size;
	u32 *dl;	/* Data (relative) location */

	for (i = 0; i < tp->nr_args; i++) {
		if (unlikely(tp->args[i].fetch_size.fn)) {
			/*
			 * First, we set the relative location and
			 * maximum data length to *dl
			 */
			dl = (u32 *)(data + tp->args[i].offset);
			*dl = make_data_rloc(maxlen, end - tp->args[i].offset);
			/* Then try to fetch string or dynamic array data */
			call_fetch(&tp->args[i].fetch, regs, dl);
			/* Reduce maximum length */
			end += get_rloc_len(*dl);
			maxlen -= get_rloc_len(*dl);
			/* Trick here, convert data_rloc to data_loc */
			*dl = convert_rloc_to_loc(*dl,
				 ent_size + tp->args[i].offset);
		} else
			/* Just fetching data normally */
			call_fetch(&tp->args[i].fetch, regs,
				   data + tp->args[i].offset);
	}
}
Commit	Line	Data
8ab83f56 SD	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
84	/* Data fetch function type */
85	typedef void (fetch_func_t)(struct pt_regs , void , void );
86	/* Printing function type */
87	typedef int (print_type_func_t)(struct trace_seq , const char , void , void *);
88
89	/* Fetch types */
90	enum {
91	FETCH_MTD_reg = 0,
92	FETCH_MTD_stack,
93	FETCH_MTD_retval,
94	FETCH_MTD_memory,
95	FETCH_MTD_symbol,
96	FETCH_MTD_deref,
97	FETCH_MTD_bitfield,
98	FETCH_MTD_END,
99	};
100
101	/* Fetch type information table */
102	struct fetch_type {
103	const char name; / Name of type */
104	size_t size; /* Byte size of type */
105	int is_signed; /* Signed flag */
106	print_type_func_t print; /* Print functions */
107	const char fmt; / Fromat string */
108	const char fmttype; / Name in format file */
109	/* Fetch functions */
110	fetch_func_t fetch[FETCH_MTD_END];
111	};
112
113	struct fetch_param {
114	fetch_func_t fn;
115	void *data;
116	};
117
118	struct probe_arg {
119	struct fetch_param fetch;
120	struct fetch_param fetch_size;
121	unsigned int offset; /* Offset from argument entry */
122	const char name; / Name of this argument */
123	const char comm; / Command of this argument */
124	const struct fetch_type type; / Type of this argument */
125	};
126
c31ffb3f NK	127	struct trace_probe {
	128	unsigned int flags; /* For TP_FLAG_* */
	129	struct ftrace_event_class class;
	130	struct ftrace_event_call call;
	131	struct list_head files;
	132	ssize_t size; /* trace entry size */
	133	unsigned int nr_args;
	134	struct probe_arg args[];
	135	};
	136
	137	static inline bool trace_probe_is_enabled(struct trace_probe *tp)
	138	{
	139	return !!(tp->flags & (TP_FLAG_TRACE \| TP_FLAG_PROFILE));
	140	}
	141
	142	static inline bool trace_probe_is_registered(struct trace_probe *tp)
	143	{
	144	return !!(tp->flags & TP_FLAG_REGISTERED);
	145	}
	146
8ab83f56 SD	147	static inline __kprobes void call_fetch(struct fetch_param *fprm,
	148	struct pt_regs regs, void dest)
	149	{
	150	return fprm->fn(regs, fprm->data, dest);
	151	}
	152
	153	/* Check the name is good for event/group/fields */
	154	static inline int is_good_name(const char *name)
	155	{
	156	if (!isalpha(name) && name != '_')
	157	return 0;
	158	while (*++name != '\0') {
	159	if (!isalpha(name) && !isdigit(name) && *name != '_')
	160	return 0;
	161	}
	162	return 1;
	163	}
	164
	165	extern int traceprobe_parse_probe_arg(char arg, ssize_t size,
f3f096cf	166	struct probe_arg *parg, bool is_return, bool is_kprobe);
8ab83f56 SD	167
	168	extern int traceprobe_conflict_field_name(const char *name,
	169	struct probe_arg *args, int narg);
	170
	171	extern void traceprobe_update_arg(struct probe_arg *arg);
	172	extern void traceprobe_free_probe_arg(struct probe_arg *arg);
	173
	174	extern int traceprobe_split_symbol_offset(char symbol, unsigned long offset);
	175
	176	extern ssize_t traceprobe_probes_write(struct file *file,
	177	const char __user buffer, size_t count, loff_t ppos,
	178	int (createfn)(int, char*));
	179
	180	extern int traceprobe_command(const char buf, int (createfn)(int, char**));
2dc10183 NK	181
	182	/* Sum up total data length for dynamic arraies (strings) */
	183	static inline __kprobes int
	184	__get_data_size(struct trace_probe tp, struct pt_regs regs)
	185	{
	186	int i, ret = 0;
	187	u32 len;
	188
	189	for (i = 0; i < tp->nr_args; i++)
	190	if (unlikely(tp->args[i].fetch_size.fn)) {
	191	call_fetch(&tp->args[i].fetch_size, regs, &len);
	192	ret += len;
	193	}
	194
	195	return ret;
	196	}
	197
	198	/* Store the value of each argument */
	199	static inline __kprobes void
	200	store_trace_args(int ent_size, struct trace_probe tp, struct pt_regs regs,
	201	u8 *data, int maxlen)
	202	{
	203	int i;
	204	u32 end = tp->size;
	205	u32 dl; / Data (relative) location */
	206
	207	for (i = 0; i < tp->nr_args; i++) {
	208	if (unlikely(tp->args[i].fetch_size.fn)) {
	209	/*
	210	* First, we set the relative location and
	211	* maximum data length to *dl
	212	*/
	213	dl = (u32 *)(data + tp->args[i].offset);
	214	*dl = make_data_rloc(maxlen, end - tp->args[i].offset);
	215	/* Then try to fetch string or dynamic array data */
	216	call_fetch(&tp->args[i].fetch, regs, dl);
	217	/* Reduce maximum length */
	218	end += get_rloc_len(*dl);
	219	maxlen -= get_rloc_len(*dl);
	220	/* Trick here, convert data_rloc to data_loc */
	221	dl = convert_rloc_to_loc(dl,
	222	ent_size + tp->args[i].offset);
	223	} else
	224	/* Just fetching data normally */
	225	call_fetch(&tp->args[i].fetch, regs,
	226	data + tp->args[i].offset);
	227	}
	228	}