[deliverable/linux.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
 */

#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(type, fmt)				\
int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name,	\
				void *data, void *ent)			\
{									\
	return trace_seq_printf(s, " %s=" fmt, name, *(type *)data);	\
}									\
const char PRINT_TYPE_FMT_NAME(type)[] = fmt;				\
NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type));

DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "0x%x")
DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "0x%Lx")
DEFINE_BASIC_PRINT_TYPE_FUNC(s8,  "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")

/* 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)
		return trace_seq_printf(s, " %s=(fault)", name);
	else
		return trace_seq_printf(s, " %s=\"%s\"", name,
					(const char *)get_loc_data(data, ent));
}
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);
}

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, unsigned long *offset)
{
	char *tmp;
	int ret;

	if (!offset)
		return -EINVAL;

	tmp = strchr(symbol, '+');
	if (tmp) {
		/* skip sign because kstrtoul doesn't accept '+' */
		ret = kstrtoul(tmp + 1, 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
		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;

	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
	BUG_ON(ftbl == NULL);

	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);
			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;

	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
	BUG_ON(ftbl == NULL);

	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++;
	}
	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);

	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);
}

int traceprobe_command(const char *buf, int (*createfn)(int, char **))
{
	char **argv;
	int argc, ret;

	argc = 0;
	ret = 0;
	argv = argv_split(GFP_KERNEL, buf, &argc);
	if (!argv)
		return -ENOMEM;

	if (argc)
		ret = createfn(argc, argv);

	argv_free(argv);

	return ret;
}

#define WRITE_BUFSIZE  4096

ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
				size_t count, loff_t *ppos,
				int (*createfn)(int, char **))
{
	char *kbuf, *tmp;
	int ret = 0;
	size_t done = 0;
	size_t size;

	kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
	if (!kbuf)
		return -ENOMEM;

	while (done < count) {
		size = count - done;

		if (size >= WRITE_BUFSIZE)
			size = WRITE_BUFSIZE - 1;

		if (copy_from_user(kbuf, buffer + done, size)) {
			ret = -EFAULT;
			goto out;
		}
		kbuf[size] = '\0';
		tmp = strchr(kbuf, '\n');

		if (tmp) {
			*tmp = '\0';
			size = tmp - kbuf + 1;
		} else if (done + size < count) {
			pr_warning("Line length is too long: "
				   "Should be less than %d.", WRITE_BUFSIZE);
			ret = -EINVAL;
			goto out;
		}
		done += size;
		/* Remove comments */
		tmp = strchr(kbuf, '#');

		if (tmp)
			*tmp = '\0';

		ret = traceprobe_command(kbuf, createfn);
		if (ret)
			goto out;
	}
	ret = done;

out:
	kfree(kbuf);

	return ret;
}

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	*/
	24
	25	#include "trace_probe.h"
	26
	27	const char *reserved_field_names[] = {
	28	"common_type",
	29	"common_flags",
	30	"common_preempt_count",
	31	"common_pid",
	32	"common_tgid",
	33	FIELD_STRING_IP,
	34	FIELD_STRING_RETIP,
	35	FIELD_STRING_FUNC,
	36	};
	37
8ab83f56	38	/* Printing in basic type function template */
50eb2672	39	#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt) \
3da0f180 MH	40	int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq s, const char name, \
3da0f180 MH	41	void data, void ent) \
8ab83f56	42	{ \
50eb2672	43	return trace_seq_printf(s, " %s=" fmt, name, (type )data); \
8ab83f56	44	} \
3da0f180 MH	45	const char PRINT_TYPE_FMT_NAME(type)[] = fmt; \
3da0f180 MH	46	NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type));
8ab83f56	47
50eb2672 NK	48	DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x")
	49	DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x")
	50	DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "0x%x")
	51	DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "0x%Lx")
	52	DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d")
	53	DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
	54	DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
	55	DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
8ab83f56	56
8ab83f56	57	/* Print type function for string type */
3da0f180 MH	58	int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq s, const char name,
3da0f180 MH	59	void data, void ent)
8ab83f56 SD	60	{
	61	int len = (u32 )data >> 16;
	62
	63	if (!len)
	64	return trace_seq_printf(s, " %s=(fault)", name);
	65	else
	66	return trace_seq_printf(s, " %s=\"%s\"", name,
	67	(const char *)get_loc_data(data, ent));
	68	}
3da0f180	69	NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
8ab83f56	70
b26c74e1	71	const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
8ab83f56	72
8ab83f56 SD	73	#define CHECK_FETCH_FUNCS(method, fn) \
	74	(((FETCH_FUNC_NAME(method, u8) == fn) \|\| \
	75	(FETCH_FUNC_NAME(method, u16) == fn) \|\| \
	76	(FETCH_FUNC_NAME(method, u32) == fn) \|\| \
	77	(FETCH_FUNC_NAME(method, u64) == fn) \|\| \
	78	(FETCH_FUNC_NAME(method, string) == fn) \|\| \
	79	(FETCH_FUNC_NAME(method, string_size) == fn)) \
	80	&& (fn != NULL))
	81
	82	/* Data fetch function templates */
	83	#define DEFINE_FETCH_reg(type) \
3da0f180	84	void FETCH_FUNC_NAME(reg, type)(struct pt_regs regs, void offset, void *dest) \
8ab83f56 SD	85	{ \
	86	(type )dest = (type)regs_get_register(regs, \
	87	(unsigned int)((unsigned long)offset)); \
3da0f180 MH	88	} \
3da0f180 MH	89	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
8ab83f56 SD	90	DEFINE_BASIC_FETCH_FUNCS(reg)
	91	/* No string on the register */
	92	#define fetch_reg_string NULL
	93	#define fetch_reg_string_size NULL
	94
8ab83f56	95	#define DEFINE_FETCH_retval(type) \
3da0f180 MH	96	void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
3da0f180 MH	97	void dummy, void dest) \
8ab83f56 SD	98	{ \
8ab83f56 SD	99	(type )dest = (type)regs_return_value(regs); \
3da0f180 MH	100	} \
3da0f180 MH	101	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
8ab83f56 SD	102	DEFINE_BASIC_FETCH_FUNCS(retval)
	103	/* No string on the retval */
	104	#define fetch_retval_string NULL
	105	#define fetch_retval_string_size NULL
	106
8ab83f56 SD	107	/* Dereference memory access function */
	108	struct deref_fetch_param {
	109	struct fetch_param orig;
	110	long offset;
3925f4a5 HL	111	fetch_func_t fetch;
3925f4a5 HL	112	fetch_func_t fetch_size;
8ab83f56 SD	113	};
	114
	115	#define DEFINE_FETCH_deref(type) \
3da0f180 MH	116	void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
3da0f180 MH	117	void data, void dest) \
8ab83f56 SD	118	{ \
	119	struct deref_fetch_param *dprm = data; \
	120	unsigned long addr; \
	121	call_fetch(&dprm->orig, regs, &addr); \
	122	if (addr) { \
	123	addr += dprm->offset; \
3925f4a5	124	dprm->fetch(regs, (void *)addr, dest); \
8ab83f56 SD	125	} else \
8ab83f56 SD	126	(type )dest = 0; \
3da0f180 MH	127	} \
3da0f180 MH	128	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
8ab83f56 SD	129	DEFINE_BASIC_FETCH_FUNCS(deref)
8ab83f56 SD	130	DEFINE_FETCH_deref(string)
3925f4a5	131
3da0f180 MH	132	void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
3da0f180 MH	133	void data, void dest)
3925f4a5 HL	134	{
	135	struct deref_fetch_param *dprm = data;
	136	unsigned long addr;
	137
	138	call_fetch(&dprm->orig, regs, &addr);
	139	if (addr && dprm->fetch_size) {
	140	addr += dprm->offset;
	141	dprm->fetch_size(regs, (void *)addr, dest);
	142	} else
	143	(string_size )dest = 0;
	144	}
3da0f180	145	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));
8ab83f56	146
3da0f180	147	static void update_deref_fetch_param(struct deref_fetch_param *data)
8ab83f56 SD	148	{
	149	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	150	update_deref_fetch_param(data->orig.data);
	151	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	152	update_symbol_cache(data->orig.data);
	153	}
3da0f180	154	NOKPROBE_SYMBOL(update_deref_fetch_param);
8ab83f56	155
3da0f180	156	static void free_deref_fetch_param(struct deref_fetch_param *data)
8ab83f56 SD	157	{
	158	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	159	free_deref_fetch_param(data->orig.data);
	160	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	161	free_symbol_cache(data->orig.data);
	162	kfree(data);
	163	}
3da0f180	164	NOKPROBE_SYMBOL(free_deref_fetch_param);
8ab83f56 SD	165
	166	/* Bitfield fetch function */
	167	struct bitfield_fetch_param {
	168	struct fetch_param orig;
	169	unsigned char hi_shift;
	170	unsigned char low_shift;
	171	};
	172
	173	#define DEFINE_FETCH_bitfield(type) \
3da0f180 MH	174	void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
3da0f180 MH	175	void data, void dest) \
8ab83f56 SD	176	{ \
	177	struct bitfield_fetch_param *bprm = data; \
	178	type buf = 0; \
	179	call_fetch(&bprm->orig, regs, &buf); \
	180	if (buf) { \
	181	buf <<= bprm->hi_shift; \
	182	buf >>= bprm->low_shift; \
	183	} \
	184	(type )dest = buf; \
3da0f180 MH	185	} \
3da0f180 MH	186	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
8ab83f56 SD	187	DEFINE_BASIC_FETCH_FUNCS(bitfield)
	188	#define fetch_bitfield_string NULL
	189	#define fetch_bitfield_string_size NULL
	190
fbc1963d	191	static void
8ab83f56 SD	192	update_bitfield_fetch_param(struct bitfield_fetch_param *data)
	193	{
	194	/*
	195	* Don't check the bitfield itself, because this must be the
	196	* last fetch function.
	197	*/
	198	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	199	update_deref_fetch_param(data->orig.data);
	200	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	201	update_symbol_cache(data->orig.data);
	202	}
	203
fbc1963d	204	static void
8ab83f56 SD	205	free_bitfield_fetch_param(struct bitfield_fetch_param *data)
	206	{
	207	/*
	208	* Don't check the bitfield itself, because this must be the
	209	* last fetch function.
	210	*/
	211	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	212	free_deref_fetch_param(data->orig.data);
	213	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	214	free_symbol_cache(data->orig.data);
	215
	216	kfree(data);
	217	}
	218
34fee3a1 NK	219	static const struct fetch_type find_fetch_type(const char type,
34fee3a1 NK	220	const struct fetch_type *ftbl)
8ab83f56 SD	221	{
	222	int i;
	223
	224	if (!type)
	225	type = DEFAULT_FETCH_TYPE_STR;
	226
	227	/* Special case: bitfield */
	228	if (*type == 'b') {
	229	unsigned long bs;
	230
	231	type = strchr(type, '/');
	232	if (!type)
	233	goto fail;
	234
	235	type++;
bcd83ea6	236	if (kstrtoul(type, 0, &bs))
8ab83f56 SD	237	goto fail;
	238
	239	switch (bs) {
	240	case 8:
34fee3a1	241	return find_fetch_type("u8", ftbl);
8ab83f56	242	case 16:
34fee3a1	243	return find_fetch_type("u16", ftbl);
8ab83f56	244	case 32:
34fee3a1	245	return find_fetch_type("u32", ftbl);
8ab83f56	246	case 64:
34fee3a1	247	return find_fetch_type("u64", ftbl);
8ab83f56 SD	248	default:
	249	goto fail;
	250	}
	251	}
	252
34fee3a1 NK	253	for (i = 0; ftbl[i].name; i++) {
	254	if (strcmp(type, ftbl[i].name) == 0)
	255	return &ftbl[i];
	256	}
8ab83f56 SD	257
	258	fail:
	259	return NULL;
	260	}
	261
	262	/* Special function : only accept unsigned long */
3da0f180	263	static void fetch_kernel_stack_address(struct pt_regs regs, void dummy, void *dest)
8ab83f56 SD	264	{
	265	(unsigned long )dest = kernel_stack_pointer(regs);
	266	}
3da0f180	267	NOKPROBE_SYMBOL(fetch_kernel_stack_address);
8ab83f56	268
3da0f180	269	static void fetch_user_stack_address(struct pt_regs regs, void dummy, void *dest)
b079d374 NK	270	{
	271	(unsigned long )dest = user_stack_pointer(regs);
	272	}
3da0f180	273	NOKPROBE_SYMBOL(fetch_user_stack_address);
b079d374	274
8ab83f56	275	static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
34fee3a1 NK	276	fetch_func_t orig_fn,
34fee3a1 NK	277	const struct fetch_type *ftbl)
8ab83f56 SD	278	{
	279	int i;
	280
34fee3a1	281	if (type != &ftbl[FETCH_TYPE_STRING])
8ab83f56 SD	282	return NULL; /* Only string type needs size function */
	283
	284	for (i = 0; i < FETCH_MTD_END; i++)
	285	if (type->fetch[i] == orig_fn)
34fee3a1	286	return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
8ab83f56 SD	287
	288	WARN_ON(1); /* This should not happen */
	289
	290	return NULL;
	291	}
	292
	293	/* Split symbol and offset. */
	294	int traceprobe_split_symbol_offset(char symbol, unsigned long offset)
	295	{
	296	char *tmp;
	297	int ret;
	298
	299	if (!offset)
	300	return -EINVAL;
	301
	302	tmp = strchr(symbol, '+');
	303	if (tmp) {
bcd83ea6 DW	304	/* skip sign because kstrtoul doesn't accept '+' */
bcd83ea6 DW	305	ret = kstrtoul(tmp + 1, 0, offset);
8ab83f56 SD	306	if (ret)
	307	return ret;
	308
	309	*tmp = '\0';
	310	} else
	311	*offset = 0;
	312
	313	return 0;
	314	}
	315
	316	#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
	317
	318	static int parse_probe_vars(char arg, const struct fetch_type t,
b079d374 NK	319	struct fetch_param *f, bool is_return,
b079d374 NK	320	bool is_kprobe)
8ab83f56 SD	321	{
	322	int ret = 0;
	323	unsigned long param;
	324
	325	if (strcmp(arg, "retval") == 0) {
	326	if (is_return)
	327	f->fn = t->fetch[FETCH_MTD_retval];
	328	else
	329	ret = -EINVAL;
	330	} else if (strncmp(arg, "stack", 5) == 0) {
	331	if (arg[5] == '\0') {
b079d374 NK	332	if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
	333	return -EINVAL;
	334
	335	if (is_kprobe)
	336	f->fn = fetch_kernel_stack_address;
8ab83f56	337	else
b079d374	338	f->fn = fetch_user_stack_address;
8ab83f56	339	} else if (isdigit(arg[5])) {
bcd83ea6	340	ret = kstrtoul(arg + 5, 10, &param);
b079d374	341	if (ret \|\| (is_kprobe && param > PARAM_MAX_STACK))
8ab83f56 SD	342	ret = -EINVAL;
	343	else {
	344	f->fn = t->fetch[FETCH_MTD_stack];
	345	f->data = (void *)param;
	346	}
	347	} else
	348	ret = -EINVAL;
	349	} else
	350	ret = -EINVAL;
	351
	352	return ret;
	353	}
	354
	355	/* Recursive argument parser */
	356	static int parse_probe_arg(char arg, const struct fetch_type t,
f3f096cf	357	struct fetch_param *f, bool is_return, bool is_kprobe)
8ab83f56	358	{
34fee3a1	359	const struct fetch_type *ftbl;
8ab83f56 SD	360	unsigned long param;
	361	long offset;
	362	char *tmp;
34fee3a1	363	int ret = 0;
8ab83f56	364
34fee3a1 NK	365	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
34fee3a1 NK	366	BUG_ON(ftbl == NULL);
f3f096cf	367
8ab83f56 SD	368	switch (arg[0]) {
8ab83f56 SD	369	case '$':
b079d374	370	ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
8ab83f56 SD	371	break;
	372
	373	case '%': /* named register */
	374	ret = regs_query_register_offset(arg + 1);
	375	if (ret >= 0) {
	376	f->fn = t->fetch[FETCH_MTD_reg];
	377	f->data = (void *)(unsigned long)ret;
	378	ret = 0;
	379	}
	380	break;
	381
b7e0bf34	382	case '@': /* memory, file-offset or symbol */
8ab83f56	383	if (isdigit(arg[1])) {
bcd83ea6	384	ret = kstrtoul(arg + 1, 0, &param);
8ab83f56 SD	385	if (ret)
	386	break;
	387
	388	f->fn = t->fetch[FETCH_MTD_memory];
	389	f->data = (void *)param;
b7e0bf34 NK	390	} else if (arg[1] == '+') {
	391	/* kprobes don't support file offsets */
	392	if (is_kprobe)
	393	return -EINVAL;
	394
	395	ret = kstrtol(arg + 2, 0, &offset);
	396	if (ret)
	397	break;
	398
	399	f->fn = t->fetch[FETCH_MTD_file_offset];
	400	f->data = (void *)offset;
8ab83f56	401	} else {
b079d374 NK	402	/* uprobes don't support symbols */
	403	if (!is_kprobe)
	404	return -EINVAL;
	405
8ab83f56 SD	406	ret = traceprobe_split_symbol_offset(arg + 1, &offset);
	407	if (ret)
	408	break;
	409
	410	f->data = alloc_symbol_cache(arg + 1, offset);
	411	if (f->data)
	412	f->fn = t->fetch[FETCH_MTD_symbol];
	413	}
	414	break;
	415
	416	case '+': /* deref memory */
bcd83ea6	417	arg++; /* Skip '+', because kstrtol() rejects it. */
8ab83f56 SD	418	case '-':
	419	tmp = strchr(arg, '(');
	420	if (!tmp)
	421	break;
	422
	423	*tmp = '\0';
bcd83ea6	424	ret = kstrtol(arg, 0, &offset);
8ab83f56 SD	425
	426	if (ret)
	427	break;
	428
	429	arg = tmp + 1;
	430	tmp = strrchr(arg, ')');
	431
	432	if (tmp) {
	433	struct deref_fetch_param *dprm;
	434	const struct fetch_type *t2;
	435
34fee3a1	436	t2 = find_fetch_type(NULL, ftbl);
8ab83f56 SD	437	*tmp = '\0';
	438	dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
	439
	440	if (!dprm)
	441	return -ENOMEM;
	442
	443	dprm->offset = offset;
3925f4a5 HL	444	dprm->fetch = t->fetch[FETCH_MTD_memory];
	445	dprm->fetch_size = get_fetch_size_function(t,
	446	dprm->fetch, ftbl);
f3f096cf SD	447	ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
f3f096cf SD	448	is_kprobe);
8ab83f56 SD	449	if (ret)
	450	kfree(dprm);
	451	else {
	452	f->fn = t->fetch[FETCH_MTD_deref];
	453	f->data = (void *)dprm;
	454	}
	455	}
	456	break;
	457	}
	458	if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
	459	pr_info("%s type has no corresponding fetch method.\n", t->name);
	460	ret = -EINVAL;
	461	}
	462
	463	return ret;
	464	}
	465
	466	#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
	467
	468	/* Bitfield type needs to be parsed into a fetch function */
	469	static int __parse_bitfield_probe_arg(const char *bf,
	470	const struct fetch_type *t,
	471	struct fetch_param *f)
	472	{
	473	struct bitfield_fetch_param *bprm;
	474	unsigned long bw, bo;
	475	char *tail;
	476
	477	if (*bf != 'b')
	478	return 0;
	479
	480	bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
	481	if (!bprm)
	482	return -ENOMEM;
	483
	484	bprm->orig = *f;
	485	f->fn = t->fetch[FETCH_MTD_bitfield];
	486	f->data = (void *)bprm;
	487	bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
	488
	489	if (bw == 0 \|\| *tail != '@')
	490	return -EINVAL;
	491
	492	bf = tail + 1;
	493	bo = simple_strtoul(bf, &tail, 0);
	494
	495	if (tail == bf \|\| *tail != '/')
	496	return -EINVAL;
	497
	498	bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
	499	bprm->low_shift = bprm->hi_shift + bo;
	500
	501	return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
	502	}
	503
	504	/* String length checking wrapper */
	505	int traceprobe_parse_probe_arg(char arg, ssize_t size,
f3f096cf	506	struct probe_arg *parg, bool is_return, bool is_kprobe)
8ab83f56	507	{
34fee3a1	508	const struct fetch_type *ftbl;
8ab83f56 SD	509	const char *t;
	510	int ret;
	511
34fee3a1 NK	512	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
	513	BUG_ON(ftbl == NULL);
	514
8ab83f56 SD	515	if (strlen(arg) > MAX_ARGSTR_LEN) {
	516	pr_info("Argument is too long.: %s\n", arg);
	517	return -ENOSPC;
	518	}
	519	parg->comm = kstrdup(arg, GFP_KERNEL);
	520	if (!parg->comm) {
	521	pr_info("Failed to allocate memory for command '%s'.\n", arg);
	522	return -ENOMEM;
	523	}
	524	t = strchr(parg->comm, ':');
	525	if (t) {
	526	arg[t - parg->comm] = '\0';
	527	t++;
	528	}
34fee3a1	529	parg->type = find_fetch_type(t, ftbl);
8ab83f56 SD	530	if (!parg->type) {
	531	pr_info("Unsupported type: %s\n", t);
	532	return -EINVAL;
	533	}
	534	parg->offset = *size;
	535	*size += parg->type->size;
f3f096cf	536	ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe);
8ab83f56 SD	537
	538	if (ret >= 0 && t != NULL)
	539	ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
	540
	541	if (ret >= 0) {
	542	parg->fetch_size.fn = get_fetch_size_function(parg->type,
34fee3a1 NK	543	parg->fetch.fn,
34fee3a1 NK	544	ftbl);
8ab83f56 SD	545	parg->fetch_size.data = parg->fetch.data;
	546	}
	547
	548	return ret;
	549	}
	550
	551	/* Return 1 if name is reserved or already used by another argument */
	552	int traceprobe_conflict_field_name(const char *name,
	553	struct probe_arg *args, int narg)
	554	{
	555	int i;
	556
	557	for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
	558	if (strcmp(reserved_field_names[i], name) == 0)
	559	return 1;
	560
	561	for (i = 0; i < narg; i++)
	562	if (strcmp(args[i].name, name) == 0)
	563	return 1;
	564
	565	return 0;
	566	}
	567
	568	void traceprobe_update_arg(struct probe_arg *arg)
	569	{
	570	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
	571	update_bitfield_fetch_param(arg->fetch.data);
	572	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
	573	update_deref_fetch_param(arg->fetch.data);
	574	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
	575	update_symbol_cache(arg->fetch.data);
	576	}
	577
	578	void traceprobe_free_probe_arg(struct probe_arg *arg)
	579	{
	580	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
	581	free_bitfield_fetch_param(arg->fetch.data);
	582	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
	583	free_deref_fetch_param(arg->fetch.data);
	584	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
	585	free_symbol_cache(arg->fetch.data);
	586
	587	kfree(arg->name);
	588	kfree(arg->comm);
	589	}
	590
	591	int traceprobe_command(const char buf, int (createfn)(int, char **))
	592	{
	593	char **argv;
	594	int argc, ret;
	595
	596	argc = 0;
	597	ret = 0;
	598	argv = argv_split(GFP_KERNEL, buf, &argc);
	599	if (!argv)
	600	return -ENOMEM;
	601
	602	if (argc)
	603	ret = createfn(argc, argv);
	604
	605	argv_free(argv);
	606
	607	return ret;
	608	}
609
610	#define WRITE_BUFSIZE 4096
611
612	ssize_t traceprobe_probes_write(struct file file, const char __user buffer,
613	size_t count, loff_t *ppos,
614	int (createfn)(int, char *))
615	{
616	char kbuf, tmp;
617	int ret = 0;
618	size_t done = 0;
619	size_t size;
620
621	kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
622	if (!kbuf)
623	return -ENOMEM;
624
625	while (done < count) {
626	size = count - done;
627
628	if (size >= WRITE_BUFSIZE)
629	size = WRITE_BUFSIZE - 1;
630
631	if (copy_from_user(kbuf, buffer + done, size)) {
632	ret = -EFAULT;
633	goto out;
634	}
635	kbuf[size] = '\0';
636	tmp = strchr(kbuf, '\n');
637
638	if (tmp) {
639	*tmp = '\0';
640	size = tmp - kbuf + 1;
641	} else if (done + size < count) {
642	pr_warning("Line length is too long: "
643	"Should be less than %d.", WRITE_BUFSIZE);
644	ret = -EINVAL;
645	goto out;
646	}
647	done += size;
648	/* Remove comments */
649	tmp = strchr(kbuf, '#');
650
651	if (tmp)
652	*tmp = '\0';
653
654	ret = traceprobe_command(kbuf, createfn);
655	if (ret)
656	goto out;
657	}
658	ret = done;
659
660	out:
661	kfree(kbuf);
662
663	return ret;
664	}
5bf652aa NK	665
	666	static int __set_print_fmt(struct trace_probe tp, char buf, int len,
	667	bool is_return)
	668	{
	669	int i;
	670	int pos = 0;
	671
	672	const char fmt, arg;
	673
	674	if (!is_return) {
	675	fmt = "(%lx)";
	676	arg = "REC->" FIELD_STRING_IP;
	677	} else {
	678	fmt = "(%lx <- %lx)";
	679	arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
	680	}
	681
	682	/* When len=0, we just calculate the needed length */
	683	#define LEN_OR_ZERO (len ? len - pos : 0)
	684
	685	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
	686
	687	for (i = 0; i < tp->nr_args; i++) {
	688	pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
	689	tp->args[i].name, tp->args[i].type->fmt);
	690	}
	691
	692	pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
	693
	694	for (i = 0; i < tp->nr_args; i++) {
	695	if (strcmp(tp->args[i].type->name, "string") == 0)
	696	pos += snprintf(buf + pos, LEN_OR_ZERO,
	697	", __get_str(%s)",
	698	tp->args[i].name);
	699	else
	700	pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
	701	tp->args[i].name);
	702	}
	703
	704	#undef LEN_OR_ZERO
	705
	706	/* return the length of print_fmt */
	707	return pos;
	708	}
	709
	710	int set_print_fmt(struct trace_probe *tp, bool is_return)
	711	{
	712	int len;
	713	char *print_fmt;
	714
	715	/* First: called with 0 length to calculate the needed length */
	716	len = __set_print_fmt(tp, NULL, 0, is_return);
	717	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	718	if (!print_fmt)
	719	return -ENOMEM;
	720
	721	/* Second: actually write the @print_fmt */
	722	__set_print_fmt(tp, print_fmt, len + 1, is_return);
	723	tp->call.print_fmt = print_fmt;
	724
	725	return 0;
	726	}