[mirror_ubuntu-zesty-kernel.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)			\
{									\
	trace_seq_printf(s, " %s=" fmt, name, *(type *)data);		\
	return !trace_seq_has_overflowed(s);				\
}									\
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)
		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);
}

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	{ \
d2b0191a SRRH	43	trace_seq_printf(s, " %s=" fmt, name, (type )data); \
d2b0191a SRRH	44	return !trace_seq_has_overflowed(s); \
8ab83f56	45	} \
3da0f180 MH	46	const char PRINT_TYPE_FMT_NAME(type)[] = fmt; \
3da0f180 MH	47	NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type));
8ab83f56	48
50eb2672 NK	49	DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x")
	50	DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x")
	51	DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "0x%x")
	52	DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "0x%Lx")
	53	DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d")
	54	DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
	55	DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
	56	DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
8ab83f56	57
8ab83f56	58	/* Print type function for string type */
3da0f180 MH	59	int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq s, const char name,
3da0f180 MH	60	void data, void ent)
8ab83f56 SD	61	{
	62	int len = (u32 )data >> 16;
	63
	64	if (!len)
d2b0191a	65	trace_seq_printf(s, " %s=(fault)", name);
8ab83f56	66	else
d2b0191a SRRH	67	trace_seq_printf(s, " %s=\"%s\"", name,
	68	(const char *)get_loc_data(data, ent));
	69	return !trace_seq_has_overflowed(s);
8ab83f56	70	}
3da0f180	71	NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
8ab83f56	72
b26c74e1	73	const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
8ab83f56	74
8ab83f56 SD	75	#define CHECK_FETCH_FUNCS(method, fn) \
	76	(((FETCH_FUNC_NAME(method, u8) == fn) \|\| \
	77	(FETCH_FUNC_NAME(method, u16) == fn) \|\| \
	78	(FETCH_FUNC_NAME(method, u32) == fn) \|\| \
	79	(FETCH_FUNC_NAME(method, u64) == fn) \|\| \
	80	(FETCH_FUNC_NAME(method, string) == fn) \|\| \
	81	(FETCH_FUNC_NAME(method, string_size) == fn)) \
	82	&& (fn != NULL))
	83
	84	/* Data fetch function templates */
	85	#define DEFINE_FETCH_reg(type) \
3da0f180	86	void FETCH_FUNC_NAME(reg, type)(struct pt_regs regs, void offset, void *dest) \
8ab83f56 SD	87	{ \
	88	(type )dest = (type)regs_get_register(regs, \
	89	(unsigned int)((unsigned long)offset)); \
3da0f180 MH	90	} \
3da0f180 MH	91	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
8ab83f56 SD	92	DEFINE_BASIC_FETCH_FUNCS(reg)
	93	/* No string on the register */
	94	#define fetch_reg_string NULL
	95	#define fetch_reg_string_size NULL
	96
8ab83f56	97	#define DEFINE_FETCH_retval(type) \
3da0f180 MH	98	void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
3da0f180 MH	99	void dummy, void dest) \
8ab83f56 SD	100	{ \
8ab83f56 SD	101	(type )dest = (type)regs_return_value(regs); \
3da0f180 MH	102	} \
3da0f180 MH	103	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
8ab83f56 SD	104	DEFINE_BASIC_FETCH_FUNCS(retval)
	105	/* No string on the retval */
	106	#define fetch_retval_string NULL
	107	#define fetch_retval_string_size NULL
	108
8ab83f56 SD	109	/* Dereference memory access function */
	110	struct deref_fetch_param {
	111	struct fetch_param orig;
	112	long offset;
3925f4a5 HL	113	fetch_func_t fetch;
3925f4a5 HL	114	fetch_func_t fetch_size;
8ab83f56 SD	115	};
	116
	117	#define DEFINE_FETCH_deref(type) \
3da0f180 MH	118	void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
3da0f180 MH	119	void data, void dest) \
8ab83f56 SD	120	{ \
	121	struct deref_fetch_param *dprm = data; \
	122	unsigned long addr; \
	123	call_fetch(&dprm->orig, regs, &addr); \
	124	if (addr) { \
	125	addr += dprm->offset; \
3925f4a5	126	dprm->fetch(regs, (void *)addr, dest); \
8ab83f56 SD	127	} else \
8ab83f56 SD	128	(type )dest = 0; \
3da0f180 MH	129	} \
3da0f180 MH	130	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
8ab83f56 SD	131	DEFINE_BASIC_FETCH_FUNCS(deref)
8ab83f56 SD	132	DEFINE_FETCH_deref(string)
3925f4a5	133
3da0f180 MH	134	void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
3da0f180 MH	135	void data, void dest)
3925f4a5 HL	136	{
	137	struct deref_fetch_param *dprm = data;
	138	unsigned long addr;
	139
	140	call_fetch(&dprm->orig, regs, &addr);
	141	if (addr && dprm->fetch_size) {
	142	addr += dprm->offset;
	143	dprm->fetch_size(regs, (void *)addr, dest);
	144	} else
	145	(string_size )dest = 0;
	146	}
3da0f180	147	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));
8ab83f56	148
3da0f180	149	static void update_deref_fetch_param(struct deref_fetch_param *data)
8ab83f56 SD	150	{
	151	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	152	update_deref_fetch_param(data->orig.data);
	153	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	154	update_symbol_cache(data->orig.data);
	155	}
3da0f180	156	NOKPROBE_SYMBOL(update_deref_fetch_param);
8ab83f56	157
3da0f180	158	static void free_deref_fetch_param(struct deref_fetch_param *data)
8ab83f56 SD	159	{
	160	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	161	free_deref_fetch_param(data->orig.data);
	162	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	163	free_symbol_cache(data->orig.data);
	164	kfree(data);
	165	}
3da0f180	166	NOKPROBE_SYMBOL(free_deref_fetch_param);
8ab83f56 SD	167
	168	/* Bitfield fetch function */
	169	struct bitfield_fetch_param {
	170	struct fetch_param orig;
	171	unsigned char hi_shift;
	172	unsigned char low_shift;
	173	};
	174
	175	#define DEFINE_FETCH_bitfield(type) \
3da0f180 MH	176	void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
3da0f180 MH	177	void data, void dest) \
8ab83f56 SD	178	{ \
	179	struct bitfield_fetch_param *bprm = data; \
	180	type buf = 0; \
	181	call_fetch(&bprm->orig, regs, &buf); \
	182	if (buf) { \
	183	buf <<= bprm->hi_shift; \
	184	buf >>= bprm->low_shift; \
	185	} \
	186	(type )dest = buf; \
3da0f180 MH	187	} \
3da0f180 MH	188	NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
8ab83f56 SD	189	DEFINE_BASIC_FETCH_FUNCS(bitfield)
	190	#define fetch_bitfield_string NULL
	191	#define fetch_bitfield_string_size NULL
	192
fbc1963d	193	static void
8ab83f56 SD	194	update_bitfield_fetch_param(struct bitfield_fetch_param *data)
	195	{
	196	/*
	197	* Don't check the bitfield itself, because this must be the
	198	* last fetch function.
	199	*/
	200	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	201	update_deref_fetch_param(data->orig.data);
	202	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	203	update_symbol_cache(data->orig.data);
	204	}
	205
fbc1963d	206	static void
8ab83f56 SD	207	free_bitfield_fetch_param(struct bitfield_fetch_param *data)
	208	{
	209	/*
	210	* Don't check the bitfield itself, because this must be the
	211	* last fetch function.
	212	*/
	213	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
	214	free_deref_fetch_param(data->orig.data);
	215	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
	216	free_symbol_cache(data->orig.data);
	217
	218	kfree(data);
	219	}
	220
34fee3a1 NK	221	static const struct fetch_type find_fetch_type(const char type,
34fee3a1 NK	222	const struct fetch_type *ftbl)
8ab83f56 SD	223	{
	224	int i;
	225
	226	if (!type)
	227	type = DEFAULT_FETCH_TYPE_STR;
	228
	229	/* Special case: bitfield */
	230	if (*type == 'b') {
	231	unsigned long bs;
	232
	233	type = strchr(type, '/');
	234	if (!type)
	235	goto fail;
	236
	237	type++;
bcd83ea6	238	if (kstrtoul(type, 0, &bs))
8ab83f56 SD	239	goto fail;
	240
	241	switch (bs) {
	242	case 8:
34fee3a1	243	return find_fetch_type("u8", ftbl);
8ab83f56	244	case 16:
34fee3a1	245	return find_fetch_type("u16", ftbl);
8ab83f56	246	case 32:
34fee3a1	247	return find_fetch_type("u32", ftbl);
8ab83f56	248	case 64:
34fee3a1	249	return find_fetch_type("u64", ftbl);
8ab83f56 SD	250	default:
	251	goto fail;
	252	}
	253	}
	254
34fee3a1 NK	255	for (i = 0; ftbl[i].name; i++) {
	256	if (strcmp(type, ftbl[i].name) == 0)
	257	return &ftbl[i];
	258	}
8ab83f56 SD	259
	260	fail:
	261	return NULL;
	262	}
	263
	264	/* Special function : only accept unsigned long */
3da0f180	265	static void fetch_kernel_stack_address(struct pt_regs regs, void dummy, void *dest)
8ab83f56 SD	266	{
	267	(unsigned long )dest = kernel_stack_pointer(regs);
	268	}
3da0f180	269	NOKPROBE_SYMBOL(fetch_kernel_stack_address);
8ab83f56	270
3da0f180	271	static void fetch_user_stack_address(struct pt_regs regs, void dummy, void *dest)
b079d374 NK	272	{
	273	(unsigned long )dest = user_stack_pointer(regs);
	274	}
3da0f180	275	NOKPROBE_SYMBOL(fetch_user_stack_address);
b079d374	276
8ab83f56	277	static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
34fee3a1 NK	278	fetch_func_t orig_fn,
34fee3a1 NK	279	const struct fetch_type *ftbl)
8ab83f56 SD	280	{
	281	int i;
	282
34fee3a1	283	if (type != &ftbl[FETCH_TYPE_STRING])
8ab83f56 SD	284	return NULL; /* Only string type needs size function */
	285
	286	for (i = 0; i < FETCH_MTD_END; i++)
	287	if (type->fetch[i] == orig_fn)
34fee3a1	288	return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
8ab83f56 SD	289
	290	WARN_ON(1); /* This should not happen */
	291
	292	return NULL;
	293	}
	294
	295	/* Split symbol and offset. */
	296	int traceprobe_split_symbol_offset(char symbol, unsigned long offset)
	297	{
	298	char *tmp;
	299	int ret;
	300
	301	if (!offset)
	302	return -EINVAL;
	303
	304	tmp = strchr(symbol, '+');
	305	if (tmp) {
bcd83ea6 DW	306	/* skip sign because kstrtoul doesn't accept '+' */
bcd83ea6 DW	307	ret = kstrtoul(tmp + 1, 0, offset);
8ab83f56 SD	308	if (ret)
	309	return ret;
	310
	311	*tmp = '\0';
	312	} else
	313	*offset = 0;
	314
	315	return 0;
	316	}
	317
	318	#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
	319
	320	static int parse_probe_vars(char arg, const struct fetch_type t,
b079d374 NK	321	struct fetch_param *f, bool is_return,
b079d374 NK	322	bool is_kprobe)
8ab83f56 SD	323	{
	324	int ret = 0;
	325	unsigned long param;
	326
	327	if (strcmp(arg, "retval") == 0) {
	328	if (is_return)
	329	f->fn = t->fetch[FETCH_MTD_retval];
	330	else
	331	ret = -EINVAL;
	332	} else if (strncmp(arg, "stack", 5) == 0) {
	333	if (arg[5] == '\0') {
b079d374 NK	334	if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
	335	return -EINVAL;
	336
	337	if (is_kprobe)
	338	f->fn = fetch_kernel_stack_address;
8ab83f56	339	else
b079d374	340	f->fn = fetch_user_stack_address;
8ab83f56	341	} else if (isdigit(arg[5])) {
bcd83ea6	342	ret = kstrtoul(arg + 5, 10, &param);
b079d374	343	if (ret \|\| (is_kprobe && param > PARAM_MAX_STACK))
8ab83f56 SD	344	ret = -EINVAL;
	345	else {
	346	f->fn = t->fetch[FETCH_MTD_stack];
	347	f->data = (void *)param;
	348	}
	349	} else
	350	ret = -EINVAL;
	351	} else
	352	ret = -EINVAL;
	353
	354	return ret;
	355	}
	356
	357	/* Recursive argument parser */
	358	static int parse_probe_arg(char arg, const struct fetch_type t,
f3f096cf	359	struct fetch_param *f, bool is_return, bool is_kprobe)
8ab83f56	360	{
34fee3a1	361	const struct fetch_type *ftbl;
8ab83f56 SD	362	unsigned long param;
	363	long offset;
	364	char *tmp;
34fee3a1	365	int ret = 0;
8ab83f56	366
34fee3a1 NK	367	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
34fee3a1 NK	368	BUG_ON(ftbl == NULL);
f3f096cf	369
8ab83f56 SD	370	switch (arg[0]) {
8ab83f56 SD	371	case '$':
b079d374	372	ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
8ab83f56 SD	373	break;
	374
	375	case '%': /* named register */
	376	ret = regs_query_register_offset(arg + 1);
	377	if (ret >= 0) {
	378	f->fn = t->fetch[FETCH_MTD_reg];
	379	f->data = (void *)(unsigned long)ret;
	380	ret = 0;
	381	}
	382	break;
	383
b7e0bf34	384	case '@': /* memory, file-offset or symbol */
8ab83f56	385	if (isdigit(arg[1])) {
bcd83ea6	386	ret = kstrtoul(arg + 1, 0, &param);
8ab83f56 SD	387	if (ret)
	388	break;
	389
	390	f->fn = t->fetch[FETCH_MTD_memory];
	391	f->data = (void *)param;
b7e0bf34 NK	392	} else if (arg[1] == '+') {
	393	/* kprobes don't support file offsets */
	394	if (is_kprobe)
	395	return -EINVAL;
	396
	397	ret = kstrtol(arg + 2, 0, &offset);
	398	if (ret)
	399	break;
	400
	401	f->fn = t->fetch[FETCH_MTD_file_offset];
	402	f->data = (void *)offset;
8ab83f56	403	} else {
b079d374 NK	404	/* uprobes don't support symbols */
	405	if (!is_kprobe)
	406	return -EINVAL;
	407
8ab83f56 SD	408	ret = traceprobe_split_symbol_offset(arg + 1, &offset);
	409	if (ret)
	410	break;
	411
	412	f->data = alloc_symbol_cache(arg + 1, offset);
	413	if (f->data)
	414	f->fn = t->fetch[FETCH_MTD_symbol];
	415	}
	416	break;
	417
	418	case '+': /* deref memory */
bcd83ea6	419	arg++; /* Skip '+', because kstrtol() rejects it. */
8ab83f56 SD	420	case '-':
	421	tmp = strchr(arg, '(');
	422	if (!tmp)
	423	break;
	424
	425	*tmp = '\0';
bcd83ea6	426	ret = kstrtol(arg, 0, &offset);
8ab83f56 SD	427
	428	if (ret)
	429	break;
	430
	431	arg = tmp + 1;
	432	tmp = strrchr(arg, ')');
	433
	434	if (tmp) {
	435	struct deref_fetch_param *dprm;
	436	const struct fetch_type *t2;
	437
34fee3a1	438	t2 = find_fetch_type(NULL, ftbl);
8ab83f56 SD	439	*tmp = '\0';
	440	dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
	441
	442	if (!dprm)
	443	return -ENOMEM;
	444
	445	dprm->offset = offset;
3925f4a5 HL	446	dprm->fetch = t->fetch[FETCH_MTD_memory];
	447	dprm->fetch_size = get_fetch_size_function(t,
	448	dprm->fetch, ftbl);
f3f096cf SD	449	ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
f3f096cf SD	450	is_kprobe);
8ab83f56 SD	451	if (ret)
	452	kfree(dprm);
	453	else {
	454	f->fn = t->fetch[FETCH_MTD_deref];
	455	f->data = (void *)dprm;
	456	}
	457	}
	458	break;
	459	}
	460	if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
	461	pr_info("%s type has no corresponding fetch method.\n", t->name);
	462	ret = -EINVAL;
	463	}
	464
	465	return ret;
	466	}
	467
	468	#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
	469
	470	/* Bitfield type needs to be parsed into a fetch function */
	471	static int __parse_bitfield_probe_arg(const char *bf,
	472	const struct fetch_type *t,
	473	struct fetch_param *f)
	474	{
	475	struct bitfield_fetch_param *bprm;
	476	unsigned long bw, bo;
	477	char *tail;
	478
	479	if (*bf != 'b')
	480	return 0;
	481
	482	bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
	483	if (!bprm)
	484	return -ENOMEM;
	485
	486	bprm->orig = *f;
	487	f->fn = t->fetch[FETCH_MTD_bitfield];
	488	f->data = (void *)bprm;
	489	bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
	490
	491	if (bw == 0 \|\| *tail != '@')
	492	return -EINVAL;
	493
	494	bf = tail + 1;
	495	bo = simple_strtoul(bf, &tail, 0);
	496
	497	if (tail == bf \|\| *tail != '/')
	498	return -EINVAL;
	499
	500	bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
	501	bprm->low_shift = bprm->hi_shift + bo;
	502
	503	return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
	504	}
	505
	506	/* String length checking wrapper */
	507	int traceprobe_parse_probe_arg(char arg, ssize_t size,
f3f096cf	508	struct probe_arg *parg, bool is_return, bool is_kprobe)
8ab83f56	509	{
34fee3a1	510	const struct fetch_type *ftbl;
8ab83f56 SD	511	const char *t;
	512	int ret;
	513
34fee3a1 NK	514	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
	515	BUG_ON(ftbl == NULL);
	516
8ab83f56 SD	517	if (strlen(arg) > MAX_ARGSTR_LEN) {
	518	pr_info("Argument is too long.: %s\n", arg);
	519	return -ENOSPC;
	520	}
	521	parg->comm = kstrdup(arg, GFP_KERNEL);
	522	if (!parg->comm) {
	523	pr_info("Failed to allocate memory for command '%s'.\n", arg);
	524	return -ENOMEM;
	525	}
	526	t = strchr(parg->comm, ':');
	527	if (t) {
	528	arg[t - parg->comm] = '\0';
	529	t++;
	530	}
34fee3a1	531	parg->type = find_fetch_type(t, ftbl);
8ab83f56 SD	532	if (!parg->type) {
	533	pr_info("Unsupported type: %s\n", t);
	534	return -EINVAL;
	535	}
	536	parg->offset = *size;
	537	*size += parg->type->size;
f3f096cf	538	ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe);
8ab83f56 SD	539
	540	if (ret >= 0 && t != NULL)
	541	ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
	542
	543	if (ret >= 0) {
	544	parg->fetch_size.fn = get_fetch_size_function(parg->type,
34fee3a1 NK	545	parg->fetch.fn,
34fee3a1 NK	546	ftbl);
8ab83f56 SD	547	parg->fetch_size.data = parg->fetch.data;
	548	}
	549
	550	return ret;
	551	}
	552
	553	/* Return 1 if name is reserved or already used by another argument */
	554	int traceprobe_conflict_field_name(const char *name,
	555	struct probe_arg *args, int narg)
	556	{
	557	int i;
	558
	559	for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
	560	if (strcmp(reserved_field_names[i], name) == 0)
	561	return 1;
	562
	563	for (i = 0; i < narg; i++)
	564	if (strcmp(args[i].name, name) == 0)
	565	return 1;
	566
	567	return 0;
	568	}
	569
	570	void traceprobe_update_arg(struct probe_arg *arg)
	571	{
	572	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
	573	update_bitfield_fetch_param(arg->fetch.data);
	574	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
	575	update_deref_fetch_param(arg->fetch.data);
	576	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
	577	update_symbol_cache(arg->fetch.data);
	578	}
	579
	580	void traceprobe_free_probe_arg(struct probe_arg *arg)
	581	{
	582	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
	583	free_bitfield_fetch_param(arg->fetch.data);
	584	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
	585	free_deref_fetch_param(arg->fetch.data);
	586	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
	587	free_symbol_cache(arg->fetch.data);
	588
	589	kfree(arg->name);
	590	kfree(arg->comm);
	591	}
	592
	593	int traceprobe_command(const char buf, int (createfn)(int, char **))
	594	{
	595	char **argv;
	596	int argc, ret;
	597
	598	argc = 0;
	599	ret = 0;
	600	argv = argv_split(GFP_KERNEL, buf, &argc);
	601	if (!argv)
	602	return -ENOMEM;
	603
	604	if (argc)
	605	ret = createfn(argc, argv);
	606
	607	argv_free(argv);
	608
	609	return ret;
	610	}
611
612	#define WRITE_BUFSIZE 4096
613
614	ssize_t traceprobe_probes_write(struct file file, const char __user buffer,
615	size_t count, loff_t *ppos,
616	int (createfn)(int, char *))
617	{
618	char kbuf, tmp;
619	int ret = 0;
620	size_t done = 0;
621	size_t size;
622
623	kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
624	if (!kbuf)
625	return -ENOMEM;
626
627	while (done < count) {
628	size = count - done;
629
630	if (size >= WRITE_BUFSIZE)
631	size = WRITE_BUFSIZE - 1;
632
633	if (copy_from_user(kbuf, buffer + done, size)) {
634	ret = -EFAULT;
635	goto out;
636	}
637	kbuf[size] = '\0';
638	tmp = strchr(kbuf, '\n');
639
640	if (tmp) {
641	*tmp = '\0';
642	size = tmp - kbuf + 1;
643	} else if (done + size < count) {
644	pr_warning("Line length is too long: "
645	"Should be less than %d.", WRITE_BUFSIZE);
646	ret = -EINVAL;
647	goto out;
648	}
649	done += size;
650	/* Remove comments */
651	tmp = strchr(kbuf, '#');
652
653	if (tmp)
654	*tmp = '\0';
655
656	ret = traceprobe_command(kbuf, createfn);
657	if (ret)
658	goto out;
659	}
660	ret = done;
661
662	out:
663	kfree(kbuf);
664
665	return ret;
666	}
5bf652aa NK	667
	668	static int __set_print_fmt(struct trace_probe tp, char buf, int len,
	669	bool is_return)
	670	{
	671	int i;
	672	int pos = 0;
	673
	674	const char fmt, arg;
	675
	676	if (!is_return) {
	677	fmt = "(%lx)";
	678	arg = "REC->" FIELD_STRING_IP;
	679	} else {
	680	fmt = "(%lx <- %lx)";
	681	arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
	682	}
	683
	684	/* When len=0, we just calculate the needed length */
	685	#define LEN_OR_ZERO (len ? len - pos : 0)
	686
	687	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
	688
	689	for (i = 0; i < tp->nr_args; i++) {
	690	pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
	691	tp->args[i].name, tp->args[i].type->fmt);
	692	}
	693
	694	pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
	695
	696	for (i = 0; i < tp->nr_args; i++) {
	697	if (strcmp(tp->args[i].type->name, "string") == 0)
	698	pos += snprintf(buf + pos, LEN_OR_ZERO,
	699	", __get_str(%s)",
	700	tp->args[i].name);
	701	else
	702	pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
	703	tp->args[i].name);
	704	}
	705
	706	#undef LEN_OR_ZERO
	707
	708	/* return the length of print_fmt */
	709	return pos;
	710	}
	711
	712	int set_print_fmt(struct trace_probe *tp, bool is_return)
	713	{
	714	int len;
	715	char *print_fmt;
	716
	717	/* First: called with 0 length to calculate the needed length */
	718	len = __set_print_fmt(tp, NULL, 0, is_return);
	719	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	720	if (!print_fmt)
	721	return -ENOMEM;
	722
	723	/* Second: actually write the @print_fmt */
	724	__set_print_fmt(tp, print_fmt, len + 1, is_return);
	725	tp->call.print_fmt = print_fmt;
	726
	727	return 0;
	728	}