[linux-2.6-block.git] / kernel / trace / trace_probe.c

/*
 * Common code 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.c written by
 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
 *
 * Updates to make this generic:
 * Copyright (C) IBM Corporation, 2010-2011
 * Author:     Srikar Dronamraju
 */
#define pr_fmt(fmt)	"trace_probe: " fmt

#include "trace_probe.h"

const char *reserved_field_names[] = {
	"common_type",
	"common_flags",
	"common_preempt_count",
	"common_pid",
	"common_tgid",
	FIELD_STRING_IP,
	FIELD_STRING_RETIP,
	FIELD_STRING_FUNC,
};

/* Printing  in basic type function template */
#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt)			\
int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name,	\
				void *data, void *ent)			\
{									\
	trace_seq_printf(s, " %s=" fmt, name, *(type *)data);		\
	return !trace_seq_has_overflowed(s);				\
}									\
const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;				\
NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname));

DEFINE_BASIC_PRINT_TYPE_FUNC(u8,  u8,  "%u")
DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
DEFINE_BASIC_PRINT_TYPE_FUNC(s8,  s8,  "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
DEFINE_BASIC_PRINT_TYPE_FUNC(x8,  u8,  "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")

/* Print type function for string type */
int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name,
				 void *data, void *ent)
{
	int len = *(u32 *)data >> 16;

	if (!len)
		trace_seq_printf(s, " %s=(fault)", name);
	else
		trace_seq_printf(s, " %s=\"%s\"", name,
				 (const char *)get_loc_data(data, ent));
	return !trace_seq_has_overflowed(s);
}
NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));

const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";

#define CHECK_FETCH_FUNCS(method, fn)			\
	(((FETCH_FUNC_NAME(method, u8) == fn) ||	\
	  (FETCH_FUNC_NAME(method, u16) == fn) ||	\
	  (FETCH_FUNC_NAME(method, u32) == fn) ||	\
	  (FETCH_FUNC_NAME(method, u64) == fn) ||	\
	  (FETCH_FUNC_NAME(method, string) == fn) ||	\
	  (FETCH_FUNC_NAME(method, string_size) == fn)) \
	 && (fn != NULL))

/* Data fetch function templates */
#define DEFINE_FETCH_reg(type)						\
void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest)	\
{									\
	*(type *)dest = (type)regs_get_register(regs,			\
				(unsigned int)((unsigned long)offset));	\
}									\
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
DEFINE_BASIC_FETCH_FUNCS(reg)
/* No string on the register */
#define fetch_reg_string	NULL
#define fetch_reg_string_size	NULL

#define DEFINE_FETCH_retval(type)					\
void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,		\
				   void *dummy, void *dest)		\
{									\
	*(type *)dest = (type)regs_return_value(regs);			\
}									\
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
DEFINE_BASIC_FETCH_FUNCS(retval)
/* No string on the retval */
#define fetch_retval_string		NULL
#define fetch_retval_string_size	NULL

/* Dereference memory access function */
struct deref_fetch_param {
	struct fetch_param	orig;
	long			offset;
	fetch_func_t		fetch;
	fetch_func_t		fetch_size;
};

#define DEFINE_FETCH_deref(type)					\
void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,			\
				  void *data, void *dest)		\
{									\
	struct deref_fetch_param *dprm = data;				\
	unsigned long addr;						\
	call_fetch(&dprm->orig, regs, &addr);				\
	if (addr) {							\
		addr += dprm->offset;					\
		dprm->fetch(regs, (void *)addr, dest);			\
	} else								\
		*(type *)dest = 0;					\
}									\
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
DEFINE_BASIC_FETCH_FUNCS(deref)
DEFINE_FETCH_deref(string)

void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
					 void *data, void *dest)
{
	struct deref_fetch_param *dprm = data;
	unsigned long addr;

	call_fetch(&dprm->orig, regs, &addr);
	if (addr && dprm->fetch_size) {
		addr += dprm->offset;
		dprm->fetch_size(regs, (void *)addr, dest);
	} else
		*(string_size *)dest = 0;
}
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));

static void update_deref_fetch_param(struct deref_fetch_param *data)
{
	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
		update_deref_fetch_param(data->orig.data);
	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
		update_symbol_cache(data->orig.data);
}
NOKPROBE_SYMBOL(update_deref_fetch_param);

static void free_deref_fetch_param(struct deref_fetch_param *data)
{
	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
		free_deref_fetch_param(data->orig.data);
	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
		free_symbol_cache(data->orig.data);
	kfree(data);
}
NOKPROBE_SYMBOL(free_deref_fetch_param);

/* Bitfield fetch function */
struct bitfield_fetch_param {
	struct fetch_param	orig;
	unsigned char		hi_shift;
	unsigned char		low_shift;
};

#define DEFINE_FETCH_bitfield(type)					\
void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,		\
				     void *data, void *dest)		\
{									\
	struct bitfield_fetch_param *bprm = data;			\
	type buf = 0;							\
	call_fetch(&bprm->orig, regs, &buf);				\
	if (buf) {							\
		buf <<= bprm->hi_shift;					\
		buf >>= bprm->low_shift;				\
	}								\
	*(type *)dest = buf;						\
}									\
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
DEFINE_BASIC_FETCH_FUNCS(bitfield)
#define fetch_bitfield_string		NULL
#define fetch_bitfield_string_size	NULL

static void
update_bitfield_fetch_param(struct bitfield_fetch_param *data)
{
	/*
	 * Don't check the bitfield itself, because this must be the
	 * last fetch function.
	 */
	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
		update_deref_fetch_param(data->orig.data);
	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
		update_symbol_cache(data->orig.data);
}

static void
free_bitfield_fetch_param(struct bitfield_fetch_param *data)
{
	/*
	 * Don't check the bitfield itself, because this must be the
	 * last fetch function.
	 */
	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
		free_deref_fetch_param(data->orig.data);
	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
		free_symbol_cache(data->orig.data);

	kfree(data);
}

void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs,
					  void *data, void *dest)
{
	int maxlen = get_rloc_len(*(u32 *)dest);
	u8 *dst = get_rloc_data(dest);
	long ret;

	if (!maxlen)
		return;

	ret = strlcpy(dst, current->comm, maxlen);
	*(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
}
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string));

void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs,
					       void *data, void *dest)
{
	*(u32 *)dest = strlen(current->comm) + 1;
}
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size));

static const struct fetch_type *find_fetch_type(const char *type,
						const struct fetch_type *ftbl)
{
	int i;

	if (!type)
		type = DEFAULT_FETCH_TYPE_STR;

	/* Special case: bitfield */
	if (*type == 'b') {
		unsigned long bs;

		type = strchr(type, '/');
		if (!type)
			goto fail;

		type++;
		if (kstrtoul(type, 0, &bs))
			goto fail;

		switch (bs) {
		case 8:
			return find_fetch_type("u8", ftbl);
		case 16:
			return find_fetch_type("u16", ftbl);
		case 32:
			return find_fetch_type("u32", ftbl);
		case 64:
			return find_fetch_type("u64", ftbl);
		default:
			goto fail;
		}
	}

	for (i = 0; ftbl[i].name; i++) {
		if (strcmp(type, ftbl[i].name) == 0)
			return &ftbl[i];
	}

fail:
	return NULL;
}

/* Special function : only accept unsigned long */
static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest)
{
	*(unsigned long *)dest = kernel_stack_pointer(regs);
}
NOKPROBE_SYMBOL(fetch_kernel_stack_address);

static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest)
{
	*(unsigned long *)dest = user_stack_pointer(regs);
}
NOKPROBE_SYMBOL(fetch_user_stack_address);

static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
					    fetch_func_t orig_fn,
					    const struct fetch_type *ftbl)
{
	int i;

	if (type != &ftbl[FETCH_TYPE_STRING])
		return NULL;	/* Only string type needs size function */

	for (i = 0; i < FETCH_MTD_END; i++)
		if (type->fetch[i] == orig_fn)
			return ftbl[FETCH_TYPE_STRSIZE].fetch[i];

	WARN_ON(1);	/* This should not happen */

	return NULL;
}

/* Split symbol and offset. */
int traceprobe_split_symbol_offset(char *symbol, long *offset)
{
	char *tmp;
	int ret;

	if (!offset)
		return -EINVAL;

	tmp = strpbrk(symbol, "+-");
	if (tmp) {
		ret = kstrtol(tmp, 0, offset);
		if (ret)
			return ret;
		*tmp = '\0';
	} else
		*offset = 0;

	return 0;
}

#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))

static int parse_probe_vars(char *arg, const struct fetch_type *t,
			    struct fetch_param *f, bool is_return,
			    bool is_kprobe)
{
	int ret = 0;
	unsigned long param;

	if (strcmp(arg, "retval") == 0) {
		if (is_return)
			f->fn = t->fetch[FETCH_MTD_retval];
		else
			ret = -EINVAL;
	} else if (strncmp(arg, "stack", 5) == 0) {
		if (arg[5] == '\0') {
			if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
				return -EINVAL;

			if (is_kprobe)
				f->fn = fetch_kernel_stack_address;
			else
				f->fn = fetch_user_stack_address;
		} else if (isdigit(arg[5])) {
			ret = kstrtoul(arg + 5, 10, &param);
			if (ret || (is_kprobe && param > PARAM_MAX_STACK))
				ret = -EINVAL;
			else {
				f->fn = t->fetch[FETCH_MTD_stack];
				f->data = (void *)param;
			}
		} else
			ret = -EINVAL;
	} else if (strcmp(arg, "comm") == 0) {
		if (strcmp(t->name, "string") != 0 &&
		    strcmp(t->name, "string_size") != 0)
			return -EINVAL;
		f->fn = t->fetch[FETCH_MTD_comm];
	} else
		ret = -EINVAL;

	return ret;
}

/* Recursive argument parser */
static int parse_probe_arg(char *arg, const struct fetch_type *t,
		     struct fetch_param *f, bool is_return, bool is_kprobe,
		     const struct fetch_type *ftbl)
{
	unsigned long param;
	long offset;
	char *tmp;
	int ret = 0;

	switch (arg[0]) {
	case '$':
		ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
		break;

	case '%':	/* named register */
		ret = regs_query_register_offset(arg + 1);
		if (ret >= 0) {
			f->fn = t->fetch[FETCH_MTD_reg];
			f->data = (void *)(unsigned long)ret;
			ret = 0;
		}
		break;

	case '@':	/* memory, file-offset or symbol */
		if (isdigit(arg[1])) {
			ret = kstrtoul(arg + 1, 0, &param);
			if (ret)
				break;

			f->fn = t->fetch[FETCH_MTD_memory];
			f->data = (void *)param;
		} else if (arg[1] == '+') {
			/* kprobes don't support file offsets */
			if (is_kprobe)
				return -EINVAL;

			ret = kstrtol(arg + 2, 0, &offset);
			if (ret)
				break;

			f->fn = t->fetch[FETCH_MTD_file_offset];
			f->data = (void *)offset;
		} else {
			/* uprobes don't support symbols */
			if (!is_kprobe)
				return -EINVAL;

			ret = traceprobe_split_symbol_offset(arg + 1, &offset);
			if (ret)
				break;

			f->data = alloc_symbol_cache(arg + 1, offset);
			if (f->data)
				f->fn = t->fetch[FETCH_MTD_symbol];
		}
		break;

	case '+':	/* deref memory */
		arg++;	/* Skip '+', because kstrtol() rejects it. */
	case '-':
		tmp = strchr(arg, '(');
		if (!tmp)
			break;

		*tmp = '\0';
		ret = kstrtol(arg, 0, &offset);

		if (ret)
			break;

		arg = tmp + 1;
		tmp = strrchr(arg, ')');

		if (tmp) {
			struct deref_fetch_param	*dprm;
			const struct fetch_type		*t2;

			t2 = find_fetch_type(NULL, ftbl);
			*tmp = '\0';
			dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);

			if (!dprm)
				return -ENOMEM;

			dprm->offset = offset;
			dprm->fetch = t->fetch[FETCH_MTD_memory];
			dprm->fetch_size = get_fetch_size_function(t,
							dprm->fetch, ftbl);
			ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
							is_kprobe, ftbl);
			if (ret)
				kfree(dprm);
			else {
				f->fn = t->fetch[FETCH_MTD_deref];
				f->data = (void *)dprm;
			}
		}
		break;
	}
	if (!ret && !f->fn) {	/* Parsed, but do not find fetch method */
		pr_info("%s type has no corresponding fetch method.\n", t->name);
		ret = -EINVAL;
	}

	return ret;
}

#define BYTES_TO_BITS(nb)	((BITS_PER_LONG * (nb)) / sizeof(long))

/* Bitfield type needs to be parsed into a fetch function */
static int __parse_bitfield_probe_arg(const char *bf,
				      const struct fetch_type *t,
				      struct fetch_param *f)
{
	struct bitfield_fetch_param *bprm;
	unsigned long bw, bo;
	char *tail;

	if (*bf != 'b')
		return 0;

	bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
	if (!bprm)
		return -ENOMEM;

	bprm->orig = *f;
	f->fn = t->fetch[FETCH_MTD_bitfield];
	f->data = (void *)bprm;
	bw = simple_strtoul(bf + 1, &tail, 0);	/* Use simple one */

	if (bw == 0 || *tail != '@')
		return -EINVAL;

	bf = tail + 1;
	bo = simple_strtoul(bf, &tail, 0);

	if (tail == bf || *tail != '/')
		return -EINVAL;

	bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
	bprm->low_shift = bprm->hi_shift + bo;

	return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
}

/* String length checking wrapper */
int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
		struct probe_arg *parg, bool is_return, bool is_kprobe,
		const struct fetch_type *ftbl)
{
	const char *t;
	int ret;

	if (strlen(arg) > MAX_ARGSTR_LEN) {
		pr_info("Argument is too long.: %s\n",  arg);
		return -ENOSPC;
	}
	parg->comm = kstrdup(arg, GFP_KERNEL);
	if (!parg->comm) {
		pr_info("Failed to allocate memory for command '%s'.\n", arg);
		return -ENOMEM;
	}
	t = strchr(parg->comm, ':');
	if (t) {
		arg[t - parg->comm] = '\0';
		t++;
	}
	/*
	 * The default type of $comm should be "string", and it can't be
	 * dereferenced.
	 */
	if (!t && strcmp(arg, "$comm") == 0)
		t = "string";
	parg->type = find_fetch_type(t, ftbl);
	if (!parg->type) {
		pr_info("Unsupported type: %s\n", t);
		return -EINVAL;
	}
	parg->offset = *size;
	*size += parg->type->size;
	ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,
			      is_kprobe, ftbl);

	if (ret >= 0 && t != NULL)
		ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);

	if (ret >= 0) {
		parg->fetch_size.fn = get_fetch_size_function(parg->type,
							      parg->fetch.fn,
							      ftbl);
		parg->fetch_size.data = parg->fetch.data;
	}

	return ret;
}

/* Return 1 if name is reserved or already used by another argument */
int traceprobe_conflict_field_name(const char *name,
			       struct probe_arg *args, int narg)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
		if (strcmp(reserved_field_names[i], name) == 0)
			return 1;

	for (i = 0; i < narg; i++)
		if (strcmp(args[i].name, name) == 0)
			return 1;

	return 0;
}

void traceprobe_update_arg(struct probe_arg *arg)
{
	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
		update_bitfield_fetch_param(arg->fetch.data);
	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
		update_deref_fetch_param(arg->fetch.data);
	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
		update_symbol_cache(arg->fetch.data);
}

void traceprobe_free_probe_arg(struct probe_arg *arg)
{
	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
		free_bitfield_fetch_param(arg->fetch.data);
	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
		free_deref_fetch_param(arg->fetch.data);
	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
		free_symbol_cache(arg->fetch.data);

	kfree(arg->name);
	kfree(arg->comm);
}

static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
			   bool is_return)
{
	int i;
	int pos = 0;

	const char *fmt, *arg;

	if (!is_return) {
		fmt = "(%lx)";
		arg = "REC->" FIELD_STRING_IP;
	} else {
		fmt = "(%lx <- %lx)";
		arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
	}

	/* When len=0, we just calculate the needed length */
#define LEN_OR_ZERO (len ? len - pos : 0)

	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);

	for (i = 0; i < tp->nr_args; i++) {
		pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
				tp->args[i].name, tp->args[i].type->fmt);
	}

	pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);

	for (i = 0; i < tp->nr_args; i++) {
		if (strcmp(tp->args[i].type->name, "string") == 0)
			pos += snprintf(buf + pos, LEN_OR_ZERO,
					", __get_str(%s)",
					tp->args[i].name);
		else
			pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
					tp->args[i].name);
	}

#undef LEN_OR_ZERO

	/* return the length of print_fmt */
	return pos;
}

int set_print_fmt(struct trace_probe *tp, bool is_return)
{
	int len;
	char *print_fmt;

	/* First: called with 0 length to calculate the needed length */
	len = __set_print_fmt(tp, NULL, 0, is_return);
	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	if (!print_fmt)
		return -ENOMEM;

	/* Second: actually write the @print_fmt */
	__set_print_fmt(tp, print_fmt, len + 1, is_return);
	tp->call.print_fmt = print_fmt;

	return 0;
}
Commit	Line	Data
8ab83f56 SD	1	/*
	2	* Common code 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.c 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	*/
72576341	24	#define pr_fmt(fmt) "trace_probe: " fmt
8ab83f56 SD	25
	26	#include "trace_probe.h"
	27
	28	const char *reserved_field_names[] = {
	29	"common_type",
	30	"common_flags",
	31	"common_preempt_count",
	32	"common_pid",
	33	"common_tgid",
	34	FIELD_STRING_IP,
	35	FIELD_STRING_RETIP,
	36	FIELD_STRING_FUNC,
	37	};
	38
8ab83f56	39	/* Printing in basic type function template */
17ce3dc7 MH	40	#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
17ce3dc7 MH	41	int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq s, const char name, \
3da0f180	42	void data, void ent) \
8ab83f56	43	{ \
d2b0191a SRRH	44	trace_seq_printf(s, " %s=" fmt, name, (type )data); \
d2b0191a SRRH	45	return !trace_seq_has_overflowed(s); \
8ab83f56	46	} \
17ce3dc7 MH	47	const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \
17ce3dc7 MH	48	NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname));
8ab83f56	49
bdca79c2 MH	50	DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
	51	DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
	52	DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
	53	DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
17ce3dc7 MH	54	DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
	55	DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
	56	DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
	57	DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
	58	DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
	59	DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
	60	DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
	61	DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
8ab83f56	62
8ab83f56	63	/* Print type function for string type */
3da0f180 MH	64	int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq s, const char name,
3da0f180 MH	65	void data, void ent)
8ab83f56 SD	66	{
	67	int len = (u32 )data >> 16;
	68
	69	if (!len)
d2b0191a	70	trace_seq_printf(s, " %s=(fault)", name);
8ab83f56	71	else
d2b0191a SRRH	72	trace_seq_printf(s, " %s=\"%s\"", name,
	73	(const char *)get_loc_data(data, ent));
	74	return !trace_seq_has_overflowed(s);
8ab83f56	75	}
3da0f180	76	NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
8ab83f56	77
b26c74e1	78	const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
8ab83f56	79
8ab83f56 SD	80	#define CHECK_FETCH_FUNCS(method, fn) \
	81	(((FETCH_FUNC_NAME(method, u8) == fn) \|\| \
	82	(FETCH_FUNC_NAME(method, u16) == fn) \|\| \
	83	(FETCH_FUNC_NAME(method, u32) == fn) \|\| \
	84	(FETCH_FUNC_NAME(method, u64) == fn) \|\| \
	85	(FETCH_FUNC_NAME(method, string) == fn) \|\| \
	86	(FETCH_FUNC_NAME(method, string_size) == fn)) \
	87	&& (fn != NULL))
	88
	89	/* Data fetch function templates */
	90	#define DEFINE_FETCH_reg(type) \
3da0f180	91	void FETCH_FUNC_NAME(reg, type)(struct pt_regs regs, void offset, void *dest) \
8ab83f56 SD	92	{ \
	93	(type )dest = (type)regs_get_register(regs, \
	94	(unsigned int)((unsigned long)offset)); \
3da0f180 MH	95	} \
3da0f180 MH	96	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
8ab83f56 SD	97	DEFINE_BASIC_FETCH_FUNCS(reg)
	98	/* No string on the register */
	99	#define fetch_reg_string NULL
	100	#define fetch_reg_string_size NULL
	101
8ab83f56	102	#define DEFINE_FETCH_retval(type) \
3da0f180 MH	103	void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
3da0f180 MH	104	void dummy, void dest) \
8ab83f56 SD	105	{ \
8ab83f56 SD	106	(type )dest = (type)regs_return_value(regs); \
3da0f180 MH	107	} \
3da0f180 MH	108	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
8ab83f56 SD	109	DEFINE_BASIC_FETCH_FUNCS(retval)
	110	/* No string on the retval */
	111	#define fetch_retval_string NULL
	112	#define fetch_retval_string_size NULL
	113
8ab83f56 SD	114	/* Dereference memory access function */
	115	struct deref_fetch_param {
	116	struct fetch_param orig;
	117	long offset;
3925f4a5 HL	118	fetch_func_t fetch;
3925f4a5 HL	119	fetch_func_t fetch_size;
8ab83f56 SD	120	};
	121
	122	#define DEFINE_FETCH_deref(type) \
3da0f180 MH	123	void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
3da0f180 MH	124	void data, void dest) \
8ab83f56 SD	125	{ \
	126	struct deref_fetch_param *dprm = data; \
	127	unsigned long addr; \
	128	call_fetch(&dprm->orig, regs, &addr); \
	129	if (addr) { \
	130	addr += dprm->offset; \
3925f4a5	131	dprm->fetch(regs, (void *)addr, dest); \
8ab83f56 SD	132	} else \
8ab83f56 SD	133	(type )dest = 0; \
3da0f180 MH	134	} \
3da0f180 MH	135	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
8ab83f56 SD	136	DEFINE_BASIC_FETCH_FUNCS(deref)
8ab83f56 SD	137	DEFINE_FETCH_deref(string)
3925f4a5	138
3da0f180 MH	139	void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
3da0f180 MH	140	void data, void dest)
3925f4a5 HL	141	{
	142	struct deref_fetch_param *dprm = data;
	143	unsigned long addr;
	144
	145	call_fetch(&dprm->orig, regs, &addr);
	146	if (addr && dprm->fetch_size) {
	147	addr += dprm->offset;
	148	dprm->fetch_size(regs, (void *)addr, dest);
	149	} else
	150	(string_size )dest = 0;
	151	}
3da0f180	152	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));
8ab83f56	153
3da0f180	154	static void update_deref_fetch_param(struct deref_fetch_param *data)
8ab83f56 SD	155	{
	156	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	157	update_deref_fetch_param(data->orig.data);
	158	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	159	update_symbol_cache(data->orig.data);
	160	}
3da0f180	161	NOKPROBE_SYMBOL(update_deref_fetch_param);
8ab83f56	162
3da0f180	163	static void free_deref_fetch_param(struct deref_fetch_param *data)
8ab83f56 SD	164	{
	165	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	166	free_deref_fetch_param(data->orig.data);
	167	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	168	free_symbol_cache(data->orig.data);
	169	kfree(data);
	170	}
3da0f180	171	NOKPROBE_SYMBOL(free_deref_fetch_param);
8ab83f56 SD	172
	173	/* Bitfield fetch function */
	174	struct bitfield_fetch_param {
	175	struct fetch_param orig;
	176	unsigned char hi_shift;
	177	unsigned char low_shift;
	178	};
	179
	180	#define DEFINE_FETCH_bitfield(type) \
3da0f180 MH	181	void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
3da0f180 MH	182	void data, void dest) \
8ab83f56 SD	183	{ \
	184	struct bitfield_fetch_param *bprm = data; \
	185	type buf = 0; \
	186	call_fetch(&bprm->orig, regs, &buf); \
	187	if (buf) { \
	188	buf <<= bprm->hi_shift; \
	189	buf >>= bprm->low_shift; \
	190	} \
	191	(type )dest = buf; \
3da0f180 MH	192	} \
3da0f180 MH	193	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
8ab83f56 SD	194	DEFINE_BASIC_FETCH_FUNCS(bitfield)
	195	#define fetch_bitfield_string NULL
	196	#define fetch_bitfield_string_size NULL
	197
fbc1963d	198	static void
8ab83f56 SD	199	update_bitfield_fetch_param(struct bitfield_fetch_param *data)
	200	{
	201	/*
	202	* Don't check the bitfield itself, because this must be the
	203	* last fetch function.
	204	*/
	205	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	206	update_deref_fetch_param(data->orig.data);
	207	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	208	update_symbol_cache(data->orig.data);
	209	}
	210
fbc1963d	211	static void
8ab83f56 SD	212	free_bitfield_fetch_param(struct bitfield_fetch_param *data)
	213	{
	214	/*
	215	* Don't check the bitfield itself, because this must be the
	216	* last fetch function.
	217	*/
	218	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	219	free_deref_fetch_param(data->orig.data);
	220	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	221	free_symbol_cache(data->orig.data);
	222
	223	kfree(data);
	224	}
	225
35abb67d OS	226	void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs,
	227	void data, void dest)
	228	{
	229	int maxlen = get_rloc_len((u32 )dest);
	230	u8 *dst = get_rloc_data(dest);
	231	long ret;
	232
	233	if (!maxlen)
	234	return;
	235
	236	ret = strlcpy(dst, current->comm, maxlen);
	237	(u32 )dest = make_data_rloc(ret, get_rloc_offs((u32 )dest));
	238	}
	239	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string));
	240
	241	void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs,
	242	void data, void dest)
	243	{
	244	(u32 )dest = strlen(current->comm) + 1;
	245	}
	246	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size));
	247
34fee3a1 NK	248	static const struct fetch_type find_fetch_type(const char type,
34fee3a1 NK	249	const struct fetch_type *ftbl)
8ab83f56 SD	250	{
	251	int i;
	252
	253	if (!type)
	254	type = DEFAULT_FETCH_TYPE_STR;
	255
	256	/* Special case: bitfield */
	257	if (*type == 'b') {
	258	unsigned long bs;
	259
	260	type = strchr(type, '/');
	261	if (!type)
	262	goto fail;
	263
	264	type++;
bcd83ea6	265	if (kstrtoul(type, 0, &bs))
8ab83f56 SD	266	goto fail;
	267
	268	switch (bs) {
	269	case 8:
34fee3a1	270	return find_fetch_type("u8", ftbl);
8ab83f56	271	case 16:
34fee3a1	272	return find_fetch_type("u16", ftbl);
8ab83f56	273	case 32:
34fee3a1	274	return find_fetch_type("u32", ftbl);
8ab83f56	275	case 64:
34fee3a1	276	return find_fetch_type("u64", ftbl);
8ab83f56 SD	277	default:
	278	goto fail;
	279	}
	280	}
	281
34fee3a1 NK	282	for (i = 0; ftbl[i].name; i++) {
	283	if (strcmp(type, ftbl[i].name) == 0)
	284	return &ftbl[i];
	285	}
8ab83f56 SD	286
	287	fail:
	288	return NULL;
	289	}
	290
	291	/* Special function : only accept unsigned long */
3da0f180	292	static void fetch_kernel_stack_address(struct pt_regs regs, void dummy, void *dest)
8ab83f56 SD	293	{
	294	(unsigned long )dest = kernel_stack_pointer(regs);
	295	}
3da0f180	296	NOKPROBE_SYMBOL(fetch_kernel_stack_address);
8ab83f56	297
3da0f180	298	static void fetch_user_stack_address(struct pt_regs regs, void dummy, void *dest)
b079d374 NK	299	{
	300	(unsigned long )dest = user_stack_pointer(regs);
	301	}
3da0f180	302	NOKPROBE_SYMBOL(fetch_user_stack_address);
b079d374	303
8ab83f56	304	static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
34fee3a1 NK	305	fetch_func_t orig_fn,
34fee3a1 NK	306	const struct fetch_type *ftbl)
8ab83f56 SD	307	{
	308	int i;
	309
34fee3a1	310	if (type != &ftbl[FETCH_TYPE_STRING])
8ab83f56 SD	311	return NULL; /* Only string type needs size function */
	312
	313	for (i = 0; i < FETCH_MTD_END; i++)
	314	if (type->fetch[i] == orig_fn)
34fee3a1	315	return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
8ab83f56 SD	316
	317	WARN_ON(1); /* This should not happen */
	318
	319	return NULL;
	320	}
	321
	322	/* Split symbol and offset. */
c5d343b6	323	int traceprobe_split_symbol_offset(char symbol, long offset)
8ab83f56 SD	324	{
	325	char *tmp;
	326	int ret;
	327
	328	if (!offset)
	329	return -EINVAL;
	330
c5d343b6	331	tmp = strpbrk(symbol, "+-");
8ab83f56	332	if (tmp) {
c5d343b6	333	ret = kstrtol(tmp, 0, offset);
8ab83f56 SD	334	if (ret)
8ab83f56 SD	335	return ret;
8ab83f56 SD	336	*tmp = '\0';
	337	} else
	338	*offset = 0;
	339
	340	return 0;
	341	}
	342
	343	#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
	344
	345	static int parse_probe_vars(char arg, const struct fetch_type t,
b079d374 NK	346	struct fetch_param *f, bool is_return,
b079d374 NK	347	bool is_kprobe)
8ab83f56 SD	348	{
	349	int ret = 0;
	350	unsigned long param;
	351
	352	if (strcmp(arg, "retval") == 0) {
	353	if (is_return)
	354	f->fn = t->fetch[FETCH_MTD_retval];
	355	else
	356	ret = -EINVAL;
	357	} else if (strncmp(arg, "stack", 5) == 0) {
	358	if (arg[5] == '\0') {
b079d374 NK	359	if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
	360	return -EINVAL;
	361
	362	if (is_kprobe)
	363	f->fn = fetch_kernel_stack_address;
8ab83f56	364	else
b079d374	365	f->fn = fetch_user_stack_address;
8ab83f56	366	} else if (isdigit(arg[5])) {
bcd83ea6	367	ret = kstrtoul(arg + 5, 10, &param);
b079d374	368	if (ret \|\| (is_kprobe && param > PARAM_MAX_STACK))
8ab83f56 SD	369	ret = -EINVAL;
	370	else {
	371	f->fn = t->fetch[FETCH_MTD_stack];
	372	f->data = (void *)param;
	373	}
	374	} else
	375	ret = -EINVAL;
35abb67d OS	376	} else if (strcmp(arg, "comm") == 0) {
	377	if (strcmp(t->name, "string") != 0 &&
	378	strcmp(t->name, "string_size") != 0)
	379	return -EINVAL;
	380	f->fn = t->fetch[FETCH_MTD_comm];
8ab83f56 SD	381	} else
	382	ret = -EINVAL;
	383
	384	return ret;
	385	}
	386
	387	/* Recursive argument parser */
	388	static int parse_probe_arg(char arg, const struct fetch_type t,
d9a16d3a SR	389	struct fetch_param *f, bool is_return, bool is_kprobe,
d9a16d3a SR	390	const struct fetch_type *ftbl)
8ab83f56 SD	391	{
	392	unsigned long param;
	393	long offset;
	394	char *tmp;
34fee3a1	395	int ret = 0;
8ab83f56	396
8ab83f56 SD	397	switch (arg[0]) {
8ab83f56 SD	398	case '$':
b079d374	399	ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
8ab83f56 SD	400	break;
	401
	402	case '%': /* named register */
	403	ret = regs_query_register_offset(arg + 1);
	404	if (ret >= 0) {
	405	f->fn = t->fetch[FETCH_MTD_reg];
	406	f->data = (void *)(unsigned long)ret;
	407	ret = 0;
	408	}
	409	break;
	410
b7e0bf34	411	case '@': /* memory, file-offset or symbol */
8ab83f56	412	if (isdigit(arg[1])) {
bcd83ea6	413	ret = kstrtoul(arg + 1, 0, &param);
8ab83f56 SD	414	if (ret)
	415	break;
	416
	417	f->fn = t->fetch[FETCH_MTD_memory];
	418	f->data = (void *)param;
b7e0bf34 NK	419	} else if (arg[1] == '+') {
	420	/* kprobes don't support file offsets */
	421	if (is_kprobe)
	422	return -EINVAL;
	423
	424	ret = kstrtol(arg + 2, 0, &offset);
	425	if (ret)
	426	break;
	427
	428	f->fn = t->fetch[FETCH_MTD_file_offset];
	429	f->data = (void *)offset;
8ab83f56	430	} else {
b079d374 NK	431	/* uprobes don't support symbols */
	432	if (!is_kprobe)
	433	return -EINVAL;
	434
8ab83f56 SD	435	ret = traceprobe_split_symbol_offset(arg + 1, &offset);
	436	if (ret)
	437	break;
	438
	439	f->data = alloc_symbol_cache(arg + 1, offset);
	440	if (f->data)
	441	f->fn = t->fetch[FETCH_MTD_symbol];
	442	}
	443	break;
	444
	445	case '+': /* deref memory */
bcd83ea6	446	arg++; /* Skip '+', because kstrtol() rejects it. */
8ab83f56 SD	447	case '-':
	448	tmp = strchr(arg, '(');
	449	if (!tmp)
	450	break;
	451
	452	*tmp = '\0';
bcd83ea6	453	ret = kstrtol(arg, 0, &offset);
8ab83f56 SD	454
	455	if (ret)
	456	break;
	457
	458	arg = tmp + 1;
	459	tmp = strrchr(arg, ')');
	460
	461	if (tmp) {
	462	struct deref_fetch_param *dprm;
	463	const struct fetch_type *t2;
	464
34fee3a1	465	t2 = find_fetch_type(NULL, ftbl);
8ab83f56 SD	466	*tmp = '\0';
	467	dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
	468
	469	if (!dprm)
	470	return -ENOMEM;
	471
	472	dprm->offset = offset;
3925f4a5 HL	473	dprm->fetch = t->fetch[FETCH_MTD_memory];
	474	dprm->fetch_size = get_fetch_size_function(t,
	475	dprm->fetch, ftbl);
f3f096cf	476	ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
d9a16d3a	477	is_kprobe, ftbl);
8ab83f56 SD	478	if (ret)
	479	kfree(dprm);
	480	else {
	481	f->fn = t->fetch[FETCH_MTD_deref];
	482	f->data = (void *)dprm;
	483	}
	484	}
	485	break;
	486	}
	487	if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
	488	pr_info("%s type has no corresponding fetch method.\n", t->name);
	489	ret = -EINVAL;
	490	}
	491
	492	return ret;
	493	}
	494
	495	#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
	496
	497	/* Bitfield type needs to be parsed into a fetch function */
	498	static int __parse_bitfield_probe_arg(const char *bf,
	499	const struct fetch_type *t,
	500	struct fetch_param *f)
	501	{
	502	struct bitfield_fetch_param *bprm;
	503	unsigned long bw, bo;
	504	char *tail;
	505
	506	if (*bf != 'b')
	507	return 0;
	508
	509	bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
	510	if (!bprm)
	511	return -ENOMEM;
	512
	513	bprm->orig = *f;
	514	f->fn = t->fetch[FETCH_MTD_bitfield];
	515	f->data = (void *)bprm;
	516	bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
	517
	518	if (bw == 0 \|\| *tail != '@')
	519	return -EINVAL;
	520
	521	bf = tail + 1;
	522	bo = simple_strtoul(bf, &tail, 0);
	523
	524	if (tail == bf \|\| *tail != '/')
	525	return -EINVAL;
	526
	527	bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
	528	bprm->low_shift = bprm->hi_shift + bo;
	529
	530	return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
	531	}
	532
	533	/* String length checking wrapper */
	534	int traceprobe_parse_probe_arg(char arg, ssize_t size,
d9a16d3a SR	535	struct probe_arg *parg, bool is_return, bool is_kprobe,
d9a16d3a SR	536	const struct fetch_type *ftbl)
8ab83f56 SD	537	{
	538	const char *t;
	539	int ret;
	540
	541	if (strlen(arg) > MAX_ARGSTR_LEN) {
	542	pr_info("Argument is too long.: %s\n", arg);
	543	return -ENOSPC;
	544	}
	545	parg->comm = kstrdup(arg, GFP_KERNEL);
	546	if (!parg->comm) {
	547	pr_info("Failed to allocate memory for command '%s'.\n", arg);
	548	return -ENOMEM;
	549	}
	550	t = strchr(parg->comm, ':');
	551	if (t) {
	552	arg[t - parg->comm] = '\0';
	553	t++;
	554	}
35abb67d OS	555	/*
	556	* The default type of $comm should be "string", and it can't be
	557	* dereferenced.
	558	*/
	559	if (!t && strcmp(arg, "$comm") == 0)
	560	t = "string";
34fee3a1	561	parg->type = find_fetch_type(t, ftbl);
8ab83f56 SD	562	if (!parg->type) {
	563	pr_info("Unsupported type: %s\n", t);
	564	return -EINVAL;
	565	}
	566	parg->offset = *size;
	567	*size += parg->type->size;
d9a16d3a SR	568	ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,
d9a16d3a SR	569	is_kprobe, ftbl);
8ab83f56 SD	570
	571	if (ret >= 0 && t != NULL)
	572	ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
	573
	574	if (ret >= 0) {
	575	parg->fetch_size.fn = get_fetch_size_function(parg->type,
34fee3a1 NK	576	parg->fetch.fn,
34fee3a1 NK	577	ftbl);
8ab83f56 SD	578	parg->fetch_size.data = parg->fetch.data;
	579	}
	580
	581	return ret;
	582	}
	583
	584	/* Return 1 if name is reserved or already used by another argument */
	585	int traceprobe_conflict_field_name(const char *name,
	586	struct probe_arg *args, int narg)
	587	{
	588	int i;
	589
	590	for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
	591	if (strcmp(reserved_field_names[i], name) == 0)
	592	return 1;
	593
	594	for (i = 0; i < narg; i++)
	595	if (strcmp(args[i].name, name) == 0)
	596	return 1;
	597
	598	return 0;
	599	}
	600
	601	void traceprobe_update_arg(struct probe_arg *arg)
	602	{
	603	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
	604	update_bitfield_fetch_param(arg->fetch.data);
	605	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
	606	update_deref_fetch_param(arg->fetch.data);
	607	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
	608	update_symbol_cache(arg->fetch.data);
	609	}
	610
	611	void traceprobe_free_probe_arg(struct probe_arg *arg)
	612	{
	613	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
	614	free_bitfield_fetch_param(arg->fetch.data);
	615	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
	616	free_deref_fetch_param(arg->fetch.data);
	617	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
	618	free_symbol_cache(arg->fetch.data);
	619
	620	kfree(arg->name);
	621	kfree(arg->comm);
	622	}
	623
5bf652aa NK	624	static int __set_print_fmt(struct trace_probe tp, char buf, int len,
	625	bool is_return)
	626	{
	627	int i;
	628	int pos = 0;
	629
	630	const char fmt, arg;
	631
	632	if (!is_return) {
	633	fmt = "(%lx)";
	634	arg = "REC->" FIELD_STRING_IP;
	635	} else {
	636	fmt = "(%lx <- %lx)";
	637	arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
	638	}
	639
	640	/* When len=0, we just calculate the needed length */
	641	#define LEN_OR_ZERO (len ? len - pos : 0)
	642
	643	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
	644
	645	for (i = 0; i < tp->nr_args; i++) {
	646	pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
	647	tp->args[i].name, tp->args[i].type->fmt);
	648	}
	649
	650	pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
	651
	652	for (i = 0; i < tp->nr_args; i++) {
	653	if (strcmp(tp->args[i].type->name, "string") == 0)
	654	pos += snprintf(buf + pos, LEN_OR_ZERO,
	655	", __get_str(%s)",
	656	tp->args[i].name);
	657	else
	658	pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
	659	tp->args[i].name);
	660	}
	661
	662	#undef LEN_OR_ZERO
	663
	664	/* return the length of print_fmt */
	665	return pos;
	666	}
	667
	668	int set_print_fmt(struct trace_probe *tp, bool is_return)
	669	{
	670	int len;
	671	char *print_fmt;
	672
	673	/* First: called with 0 length to calculate the needed length */
	674	len = __set_print_fmt(tp, NULL, 0, is_return);
	675	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	676	if (!print_fmt)
	677	return -ENOMEM;
	678
	679	/* Second: actually write the @print_fmt */
	680	__set_print_fmt(tp, print_fmt, len + 1, is_return);
	681	tp->call.print_fmt = print_fmt;
	682
	683	return 0;
	684	}