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

// SPDX-License-Identifier: GPL-2.0
/*
 * Common code for probe-based Dynamic events.
 *
 * 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"

static 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, void *data, void *ent)\
{									\
	trace_seq_printf(s, fmt, *(type *)data);			\
	return !trace_seq_has_overflowed(s);				\
}									\
const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;

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")

int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
{
	trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
	return !trace_seq_has_overflowed(s);
}
const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";

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

	if (!len)
		trace_seq_puts(s, "(fault)");
	else
		trace_seq_printf(s, "\"%s\"",
				 (const char *)get_loc_data(data, ent));
	return !trace_seq_has_overflowed(s);
}

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

/* Fetch type information table */
static const struct fetch_type probe_fetch_types[] = {
	/* Special types */
	__ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1,
			    "__data_loc char[]"),
	/* Basic types */
	ASSIGN_FETCH_TYPE(u8,  u8,  0),
	ASSIGN_FETCH_TYPE(u16, u16, 0),
	ASSIGN_FETCH_TYPE(u32, u32, 0),
	ASSIGN_FETCH_TYPE(u64, u64, 0),
	ASSIGN_FETCH_TYPE(s8,  u8,  1),
	ASSIGN_FETCH_TYPE(s16, u16, 1),
	ASSIGN_FETCH_TYPE(s32, u32, 1),
	ASSIGN_FETCH_TYPE(s64, u64, 1),
	ASSIGN_FETCH_TYPE_ALIAS(x8,  u8,  u8,  0),
	ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
	ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
	ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
	ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),

	ASSIGN_FETCH_TYPE_END
};

static const struct fetch_type *find_fetch_type(const char *type)
{
	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");
		case 16:
			return find_fetch_type("u16");
		case 32:
			return find_fetch_type("u32");
		case 64:
			return find_fetch_type("u64");
		default:
			goto fail;
		}
	}

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

fail:
	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;
}

/* @buf must has MAX_EVENT_NAME_LEN size */
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
				char *buf)
{
	const char *slash, *event = *pevent;

	slash = strchr(event, '/');
	if (slash) {
		if (slash == event) {
			pr_info("Group name is not specified\n");
			return -EINVAL;
		}
		if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
			pr_info("Group name is too long\n");
			return -E2BIG;
		}
		strlcpy(buf, event, slash - event + 1);
		*pgroup = buf;
		*pevent = slash + 1;
	}
	if (strlen(event) == 0) {
		pr_info("Event name is not specified\n");
		return -EINVAL;
	}
	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_insn *code, unsigned int flags)
{
	unsigned long param;
	int ret = 0;
	int len;

	if (strcmp(arg, "retval") == 0) {
		if (flags & TPARG_FL_RETURN)
			code->op = FETCH_OP_RETVAL;
		else
			ret = -EINVAL;
	} else if ((len = str_has_prefix(arg, "stack"))) {
		if (arg[len] == '\0') {
			code->op = FETCH_OP_STACKP;
		} else if (isdigit(arg[len])) {
			ret = kstrtoul(arg + len, 10, &param);
			if (ret || ((flags & TPARG_FL_KERNEL) &&
				    param > PARAM_MAX_STACK))
				ret = -EINVAL;
			else {
				code->op = FETCH_OP_STACK;
				code->param = (unsigned int)param;
			}
		} else
			ret = -EINVAL;
	} else if (strcmp(arg, "comm") == 0) {
		code->op = FETCH_OP_COMM;
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
	} else if (((flags & TPARG_FL_MASK) ==
		    (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
		   (len = str_has_prefix(arg, "arg"))) {
		if (!isdigit(arg[len]))
			return -EINVAL;
		ret = kstrtoul(arg + len, 10, &param);
		if (ret || !param || param > PARAM_MAX_STACK)
			return -EINVAL;
		code->op = FETCH_OP_ARG;
		code->param = (unsigned int)param - 1;
#endif
	} else
		ret = -EINVAL;

	return ret;
}

/* Recursive argument parser */
static int
parse_probe_arg(char *arg, const struct fetch_type *type,
		struct fetch_insn **pcode, struct fetch_insn *end,
		unsigned int flags)
{
	struct fetch_insn *code = *pcode;
	unsigned long param;
	long offset = 0;
	char *tmp;
	int ret = 0;

	switch (arg[0]) {
	case '$':
		ret = parse_probe_vars(arg + 1, type, code, flags);
		break;

	case '%':	/* named register */
		ret = regs_query_register_offset(arg + 1);
		if (ret >= 0) {
			code->op = FETCH_OP_REG;
			code->param = (unsigned int)ret;
			ret = 0;
		}
		break;

	case '@':	/* memory, file-offset or symbol */
		if (isdigit(arg[1])) {
			ret = kstrtoul(arg + 1, 0, &param);
			if (ret)
				break;
			/* load address */
			code->op = FETCH_OP_IMM;
			code->immediate = param;
		} else if (arg[1] == '+') {
			/* kprobes don't support file offsets */
			if (flags & TPARG_FL_KERNEL)
				return -EINVAL;

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

			code->op = FETCH_OP_FOFFS;
			code->immediate = (unsigned long)offset;  // imm64?
		} else {
			/* uprobes don't support symbols */
			if (!(flags & TPARG_FL_KERNEL))
				return -EINVAL;

			/* Preserve symbol for updating */
			code->op = FETCH_NOP_SYMBOL;
			code->data = kstrdup(arg + 1, GFP_KERNEL);
			if (!code->data)
				return -ENOMEM;
			if (++code == end)
				return -E2BIG;

			code->op = FETCH_OP_IMM;
			code->immediate = 0;
		}
		/* These are fetching from memory */
		if (++code == end)
			return -E2BIG;
		*pcode = code;
		code->op = FETCH_OP_DEREF;
		code->offset = offset;
		break;

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

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

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

		if (tmp) {
			const struct fetch_type *t2 = find_fetch_type(NULL);

			*tmp = '\0';
			ret = parse_probe_arg(arg, t2, &code, end, flags);
			if (ret)
				break;
			if (code->op == FETCH_OP_COMM)
				return -EINVAL;
			if (++code == end)
				return -E2BIG;
			*pcode = code;

			code->op = FETCH_OP_DEREF;
			code->offset = offset;
		}
		break;
	}
	if (!ret && code->op == FETCH_OP_NOP) {
		/* Parsed, but do not find fetch method */
		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_insn **pcode)
{
	struct fetch_insn *code = *pcode;
	unsigned long bw, bo;
	char *tail;

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

	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;
	code++;
	if (code->op != FETCH_OP_NOP)
		return -E2BIG;
	*pcode = code;

	code->op = FETCH_OP_MOD_BF;
	code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
	code->rshift = BYTES_TO_BITS(t->size) - bw;
	code->basesize = t->size;

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

/* String length checking wrapper */
static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
		struct probe_arg *parg, unsigned int flags)
{
	struct fetch_insn *code, *scode, *tmp = NULL;
	char *t, *t2;
	int ret, len;

	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(arg, ':');
	if (t) {
		*t = '\0';
		t2 = strchr(++t, '[');
		if (t2) {
			*t2 = '\0';
			parg->count = simple_strtoul(t2 + 1, &t2, 0);
			if (strcmp(t2, "]") || parg->count == 0)
				return -EINVAL;
			if (parg->count > MAX_ARRAY_LEN)
				return -E2BIG;
		}
	}
	/*
	 * The default type of $comm should be "string", and it can't be
	 * dereferenced.
	 */
	if (!t && strcmp(arg, "$comm") == 0)
		parg->type = find_fetch_type("string");
	else
		parg->type = find_fetch_type(t);
	if (!parg->type) {
		pr_info("Unsupported type: %s\n", t);
		return -EINVAL;
	}
	parg->offset = *size;
	*size += parg->type->size * (parg->count ?: 1);

	if (parg->count) {
		len = strlen(parg->type->fmttype) + 6;
		parg->fmt = kmalloc(len, GFP_KERNEL);
		if (!parg->fmt)
			return -ENOMEM;
		snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
			 parg->count);
	}

	code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL);
	if (!code)
		return -ENOMEM;
	code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;

	ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
			      flags);
	if (ret)
		goto fail;

	/* Store operation */
	if (!strcmp(parg->type->name, "string")) {
		if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM &&
		    code->op != FETCH_OP_COMM) {
			pr_info("string only accepts memory or address.\n");
			ret = -EINVAL;
			goto fail;
		}
		if (code->op != FETCH_OP_DEREF || parg->count) {
			/*
			 * IMM and COMM is pointing actual address, those must
			 * be kept, and if parg->count != 0, this is an array
			 * of string pointers instead of string address itself.
			 */
			code++;
			if (code->op != FETCH_OP_NOP) {
				ret = -E2BIG;
				goto fail;
			}
		}
		code->op = FETCH_OP_ST_STRING;	/* In DEREF case, replace it */
		code->size = parg->type->size;
		parg->dynamic = true;
	} else if (code->op == FETCH_OP_DEREF) {
		code->op = FETCH_OP_ST_MEM;
		code->size = parg->type->size;
	} else {
		code++;
		if (code->op != FETCH_OP_NOP) {
			ret = -E2BIG;
			goto fail;
		}
		code->op = FETCH_OP_ST_RAW;
		code->size = parg->type->size;
	}
	scode = code;
	/* Modify operation */
	if (t != NULL) {
		ret = __parse_bitfield_probe_arg(t, parg->type, &code);
		if (ret)
			goto fail;
	}
	/* Loop(Array) operation */
	if (parg->count) {
		if (scode->op != FETCH_OP_ST_MEM &&
		    scode->op != FETCH_OP_ST_STRING) {
			pr_info("array only accepts memory or address\n");
			ret = -EINVAL;
			goto fail;
		}
		code++;
		if (code->op != FETCH_OP_NOP) {
			ret = -E2BIG;
			goto fail;
		}
		code->op = FETCH_OP_LP_ARRAY;
		code->param = parg->count;
	}
	code++;
	code->op = FETCH_OP_END;

	/* Shrink down the code buffer */
	parg->code = kzalloc(sizeof(*code) * (code - tmp + 1), GFP_KERNEL);
	if (!parg->code)
		ret = -ENOMEM;
	else
		memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));

fail:
	if (ret) {
		for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
			if (code->op == FETCH_NOP_SYMBOL)
				kfree(code->data);
	}
	kfree(tmp);

	return ret;
}

/* Return 1 if name is reserved or already used by another argument */
static 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;
}

int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
				unsigned int flags)
{
	struct probe_arg *parg = &tp->args[i];
	char *body;
	int ret;

	/* Increment count for freeing args in error case */
	tp->nr_args++;

	body = strchr(arg, '=');
	if (body) {
		parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
		body++;
	} else {
		/* If argument name is omitted, set "argN" */
		parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
		body = arg;
	}
	if (!parg->name)
		return -ENOMEM;

	if (!is_good_name(parg->name)) {
		pr_info("Invalid argument[%d] name: %s\n",
			i, parg->name);
		return -EINVAL;
	}

	if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
		pr_info("Argument[%d]: '%s' conflicts with another field.\n",
			i, parg->name);
		return -EINVAL;
	}

	/* Parse fetch argument */
	ret = traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags);
	if (ret)
		pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
	return ret;
}

void traceprobe_free_probe_arg(struct probe_arg *arg)
{
	struct fetch_insn *code = arg->code;

	while (code && code->op != FETCH_OP_END) {
		if (code->op == FETCH_NOP_SYMBOL)
			kfree(code->data);
		code++;
	}
	kfree(arg->code);
	kfree(arg->name);
	kfree(arg->comm);
	kfree(arg->fmt);
}

int traceprobe_update_arg(struct probe_arg *arg)
{
	struct fetch_insn *code = arg->code;
	long offset;
	char *tmp;
	char c;
	int ret = 0;

	while (code && code->op != FETCH_OP_END) {
		if (code->op == FETCH_NOP_SYMBOL) {
			if (code[1].op != FETCH_OP_IMM)
				return -EINVAL;

			tmp = strpbrk(code->data, "+-");
			if (tmp)
				c = *tmp;
			ret = traceprobe_split_symbol_offset(code->data,
							     &offset);
			if (ret)
				return ret;

			code[1].immediate =
				(unsigned long)kallsyms_lookup_name(code->data);
			if (tmp)
				*tmp = c;
			if (!code[1].immediate)
				return -ENOENT;
			code[1].immediate += offset;
		}
		code++;
	}
	return 0;
}

/* When len=0, we just calculate the needed length */
#define LEN_OR_ZERO (len ? len - pos : 0)
static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
			   bool is_return)
{
	struct probe_arg *parg;
	int i, j;
	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;
	}

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

	for (i = 0; i < tp->nr_args; i++) {
		parg = tp->args + i;
		pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
		if (parg->count) {
			pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
					parg->type->fmt);
			for (j = 1; j < parg->count; j++)
				pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
						parg->type->fmt);
			pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
		} else
			pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
					parg->type->fmt);
	}

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

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

	/* return the length of print_fmt */
	return pos;
}
#undef LEN_OR_ZERO

int traceprobe_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;
}

int traceprobe_define_arg_fields(struct trace_event_call *event_call,
				 size_t offset, struct trace_probe *tp)
{
	int ret, i;

	/* Set argument names as fields */
	for (i = 0; i < tp->nr_args; i++) {
		struct probe_arg *parg = &tp->args[i];
		const char *fmt = parg->type->fmttype;
		int size = parg->type->size;

		if (parg->fmt)
			fmt = parg->fmt;
		if (parg->count)
			size *= parg->count;
		ret = trace_define_field(event_call, fmt, parg->name,
					 offset + parg->offset, size,
					 parg->type->is_signed,
					 FILTER_OTHER);
		if (ret)
			return ret;
	}
	return 0;
}
Commit	Line	Data
bcea3f96	1	// SPDX-License-Identifier: GPL-2.0
8ab83f56 SD	2	/*
	3	* Common code for probe-based Dynamic events.
	4	*
8ab83f56 SD	5	* This code was copied from kernel/trace/trace_kprobe.c written by
	6	* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
	7	*
	8	* Updates to make this generic:
	9	* Copyright (C) IBM Corporation, 2010-2011
	10	* Author: Srikar Dronamraju
	11	*/
72576341	12	#define pr_fmt(fmt) "trace_probe: " fmt
8ab83f56 SD	13
	14	#include "trace_probe.h"
	15
08416252	16	static const char *reserved_field_names[] = {
8ab83f56 SD	17	"common_type",
	18	"common_flags",
	19	"common_preempt_count",
	20	"common_pid",
	21	"common_tgid",
	22	FIELD_STRING_IP,
	23	FIELD_STRING_RETIP,
	24	FIELD_STRING_FUNC,
	25	};
	26
8ab83f56	27	/* Printing in basic type function template */
17ce3dc7	28	#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
56de7630	29	int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq s, void data, void *ent)\
8ab83f56	30	{ \
56de7630	31	trace_seq_printf(s, fmt, (type )data); \
d2b0191a	32	return !trace_seq_has_overflowed(s); \
8ab83f56	33	} \
7bfbc63e	34	const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
8ab83f56	35
bdca79c2 MH	36	DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
	37	DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
	38	DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
	39	DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
17ce3dc7 MH	40	DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
	41	DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
	42	DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
	43	DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
	44	DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
	45	DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
	46	DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
	47	DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
8ab83f56	48
60c2e0ce MH	49	int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq s, void data, void *ent)
	50	{
	51	trace_seq_printf(s, "%pS", (void )(unsigned long *)data);
	52	return !trace_seq_has_overflowed(s);
	53	}
	54	const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
	55
8ab83f56	56	/* Print type function for string type */
56de7630	57	int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq s, void data, void *ent)
8ab83f56 SD	58	{
	59	int len = (u32 )data >> 16;
	60
	61	if (!len)
56de7630	62	trace_seq_puts(s, "(fault)");
8ab83f56	63	else
56de7630	64	trace_seq_printf(s, "\"%s\"",
d2b0191a SRRH	65	(const char *)get_loc_data(data, ent));
d2b0191a SRRH	66	return !trace_seq_has_overflowed(s);
8ab83f56 SD	67	}
8ab83f56 SD	68
b26c74e1	69	const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
8ab83f56	70
f451bc89 MH	71	/* Fetch type information table */
	72	static const struct fetch_type probe_fetch_types[] = {
	73	/* Special types */
	74	__ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1,
	75	"__data_loc char[]"),
	76	/* Basic types */
	77	ASSIGN_FETCH_TYPE(u8, u8, 0),
	78	ASSIGN_FETCH_TYPE(u16, u16, 0),
	79	ASSIGN_FETCH_TYPE(u32, u32, 0),
	80	ASSIGN_FETCH_TYPE(u64, u64, 0),
	81	ASSIGN_FETCH_TYPE(s8, u8, 1),
	82	ASSIGN_FETCH_TYPE(s16, u16, 1),
	83	ASSIGN_FETCH_TYPE(s32, u32, 1),
	84	ASSIGN_FETCH_TYPE(s64, u64, 1),
	85	ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
	86	ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
	87	ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
	88	ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
60c2e0ce	89	ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
f451bc89 MH	90
	91	ASSIGN_FETCH_TYPE_END
	92	};
	93
	94	static const struct fetch_type find_fetch_type(const char type)
8ab83f56 SD	95	{
	96	int i;
	97
	98	if (!type)
	99	type = DEFAULT_FETCH_TYPE_STR;
	100
	101	/* Special case: bitfield */
	102	if (*type == 'b') {
	103	unsigned long bs;
	104
	105	type = strchr(type, '/');
	106	if (!type)
	107	goto fail;
	108
	109	type++;
bcd83ea6	110	if (kstrtoul(type, 0, &bs))
8ab83f56 SD	111	goto fail;
	112
	113	switch (bs) {
	114	case 8:
f451bc89	115	return find_fetch_type("u8");
8ab83f56	116	case 16:
f451bc89	117	return find_fetch_type("u16");
8ab83f56	118	case 32:
f451bc89	119	return find_fetch_type("u32");
8ab83f56	120	case 64:
f451bc89	121	return find_fetch_type("u64");
8ab83f56 SD	122	default:
	123	goto fail;
	124	}
	125	}
	126
f451bc89 MH	127	for (i = 0; probe_fetch_types[i].name; i++) {
	128	if (strcmp(type, probe_fetch_types[i].name) == 0)
	129	return &probe_fetch_types[i];
34fee3a1	130	}
8ab83f56 SD	131
	132	fail:
	133	return NULL;
	134	}
	135
8ab83f56	136	/* Split symbol and offset. */
c5d343b6	137	int traceprobe_split_symbol_offset(char symbol, long offset)
8ab83f56 SD	138	{
	139	char *tmp;
	140	int ret;
	141
	142	if (!offset)
	143	return -EINVAL;
	144
c5d343b6	145	tmp = strpbrk(symbol, "+-");
8ab83f56	146	if (tmp) {
c5d343b6	147	ret = kstrtol(tmp, 0, offset);
8ab83f56 SD	148	if (ret)
8ab83f56 SD	149	return ret;
8ab83f56 SD	150	*tmp = '\0';
	151	} else
	152	*offset = 0;
	153
	154	return 0;
	155	}
	156
6212dd29 MH	157	/* @buf must has MAX_EVENT_NAME_LEN size */
	158	int traceprobe_parse_event_name(const char pevent, const char pgroup,
	159	char *buf)
	160	{
	161	const char slash, event = *pevent;
	162
	163	slash = strchr(event, '/');
	164	if (slash) {
	165	if (slash == event) {
	166	pr_info("Group name is not specified\n");
	167	return -EINVAL;
	168	}
	169	if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
	170	pr_info("Group name is too long\n");
	171	return -E2BIG;
	172	}
	173	strlcpy(buf, event, slash - event + 1);
	174	*pgroup = buf;
	175	*pevent = slash + 1;
	176	}
	177	if (strlen(event) == 0) {
	178	pr_info("Event name is not specified\n");
	179	return -EINVAL;
	180	}
	181	return 0;
	182	}
	183
8ab83f56 SD	184	#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
	185
	186	static int parse_probe_vars(char arg, const struct fetch_type t,
a1303af5	187	struct fetch_insn *code, unsigned int flags)
8ab83f56	188	{
8ab83f56	189	unsigned long param;
3d739c1f SRV	190	int ret = 0;
3d739c1f SRV	191	int len;
8ab83f56 SD	192
8ab83f56 SD	193	if (strcmp(arg, "retval") == 0) {
a1303af5	194	if (flags & TPARG_FL_RETURN)
53305928	195	code->op = FETCH_OP_RETVAL;
8ab83f56 SD	196	else
8ab83f56 SD	197	ret = -EINVAL;
3d739c1f SRV	198	} else if ((len = str_has_prefix(arg, "stack"))) {
3d739c1f SRV	199	if (arg[len] == '\0') {
53305928	200	code->op = FETCH_OP_STACKP;
3d739c1f SRV	201	} else if (isdigit(arg[len])) {
3d739c1f SRV	202	ret = kstrtoul(arg + len, 10, &param);
a1303af5 MH	203	if (ret \|\| ((flags & TPARG_FL_KERNEL) &&
a1303af5 MH	204	param > PARAM_MAX_STACK))
8ab83f56 SD	205	ret = -EINVAL;
8ab83f56 SD	206	else {
53305928 MH	207	code->op = FETCH_OP_STACK;
53305928 MH	208	code->param = (unsigned int)param;
8ab83f56 SD	209	}
	210	} else
	211	ret = -EINVAL;
35abb67d	212	} else if (strcmp(arg, "comm") == 0) {
53305928	213	code->op = FETCH_OP_COMM;
a1303af5 MH	214	#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
	215	} else if (((flags & TPARG_FL_MASK) ==
	216	(TPARG_FL_KERNEL \| TPARG_FL_FENTRY)) &&
3d739c1f SRV	217	(len = str_has_prefix(arg, "arg"))) {
3d739c1f SRV	218	if (!isdigit(arg[len]))
a1303af5	219	return -EINVAL;
3d739c1f	220	ret = kstrtoul(arg + len, 10, &param);
a1303af5 MH	221	if (ret \|\| !param \|\| param > PARAM_MAX_STACK)
	222	return -EINVAL;
	223	code->op = FETCH_OP_ARG;
	224	code->param = (unsigned int)param - 1;
	225	#endif
8ab83f56 SD	226	} else
	227	ret = -EINVAL;
	228
	229	return ret;
	230	}
	231
	232	/* Recursive argument parser */
53305928 MH	233	static int
	234	parse_probe_arg(char arg, const struct fetch_type type,
	235	struct fetch_insn *pcode, struct fetch_insn end,
a1303af5	236	unsigned int flags)
8ab83f56	237	{
53305928	238	struct fetch_insn code = pcode;
8ab83f56	239	unsigned long param;
bf173ca9	240	long offset = 0;
8ab83f56	241	char *tmp;
34fee3a1	242	int ret = 0;
8ab83f56	243
8ab83f56 SD	244	switch (arg[0]) {
8ab83f56 SD	245	case '$':
a1303af5	246	ret = parse_probe_vars(arg + 1, type, code, flags);
8ab83f56 SD	247	break;
	248
	249	case '%': /* named register */
	250	ret = regs_query_register_offset(arg + 1);
	251	if (ret >= 0) {
53305928 MH	252	code->op = FETCH_OP_REG;
53305928 MH	253	code->param = (unsigned int)ret;
8ab83f56 SD	254	ret = 0;
	255	}
	256	break;
	257
b7e0bf34	258	case '@': /* memory, file-offset or symbol */
8ab83f56	259	if (isdigit(arg[1])) {
bcd83ea6	260	ret = kstrtoul(arg + 1, 0, &param);
8ab83f56 SD	261	if (ret)
8ab83f56 SD	262	break;
53305928 MH	263	/* load address */
	264	code->op = FETCH_OP_IMM;
	265	code->immediate = param;
b7e0bf34 NK	266	} else if (arg[1] == '+') {
b7e0bf34 NK	267	/* kprobes don't support file offsets */
a1303af5	268	if (flags & TPARG_FL_KERNEL)
b7e0bf34 NK	269	return -EINVAL;
	270
	271	ret = kstrtol(arg + 2, 0, &offset);
	272	if (ret)
	273	break;
	274
53305928 MH	275	code->op = FETCH_OP_FOFFS;
53305928 MH	276	code->immediate = (unsigned long)offset; // imm64?
8ab83f56	277	} else {
b079d374	278	/* uprobes don't support symbols */
a1303af5	279	if (!(flags & TPARG_FL_KERNEL))
b079d374 NK	280	return -EINVAL;
b079d374 NK	281
a6682814 MH	282	/* Preserve symbol for updating */
	283	code->op = FETCH_NOP_SYMBOL;
	284	code->data = kstrdup(arg + 1, GFP_KERNEL);
	285	if (!code->data)
	286	return -ENOMEM;
	287	if (++code == end)
	288	return -E2BIG;
8ab83f56	289
53305928	290	code->op = FETCH_OP_IMM;
a6682814	291	code->immediate = 0;
8ab83f56	292	}
53305928 MH	293	/* These are fetching from memory */
	294	if (++code == end)
	295	return -E2BIG;
	296	*pcode = code;
	297	code->op = FETCH_OP_DEREF;
	298	code->offset = offset;
8ab83f56 SD	299	break;
	300
	301	case '+': /* deref memory */
bcd83ea6	302	arg++; /* Skip '+', because kstrtol() rejects it. */
91457c01	303	/* fall through */
8ab83f56 SD	304	case '-':
	305	tmp = strchr(arg, '(');
	306	if (!tmp)
53305928	307	return -EINVAL;
8ab83f56 SD	308
8ab83f56 SD	309	*tmp = '\0';
bcd83ea6	310	ret = kstrtol(arg, 0, &offset);
8ab83f56 SD	311	if (ret)
	312	break;
	313
	314	arg = tmp + 1;
	315	tmp = strrchr(arg, ')');
	316
	317	if (tmp) {
f451bc89	318	const struct fetch_type *t2 = find_fetch_type(NULL);
8ab83f56	319
8ab83f56	320	*tmp = '\0';
a1303af5	321	ret = parse_probe_arg(arg, t2, &code, end, flags);
8ab83f56	322	if (ret)
53305928 MH	323	break;
	324	if (code->op == FETCH_OP_COMM)
	325	return -EINVAL;
	326	if (++code == end)
	327	return -E2BIG;
	328	*pcode = code;
	329
	330	code->op = FETCH_OP_DEREF;
	331	code->offset = offset;
8ab83f56 SD	332	}
	333	break;
	334	}
53305928 MH	335	if (!ret && code->op == FETCH_OP_NOP) {
53305928 MH	336	/* Parsed, but do not find fetch method */
8ab83f56 SD	337	ret = -EINVAL;
8ab83f56 SD	338	}
8ab83f56 SD	339	return ret;
	340	}
	341
	342	#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
	343
	344	/* Bitfield type needs to be parsed into a fetch function */
	345	static int __parse_bitfield_probe_arg(const char *bf,
	346	const struct fetch_type *t,
53305928	347	struct fetch_insn **pcode)
8ab83f56	348	{
53305928	349	struct fetch_insn code = pcode;
8ab83f56 SD	350	unsigned long bw, bo;
	351	char *tail;
	352
	353	if (*bf != 'b')
	354	return 0;
	355
8ab83f56 SD	356	bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
	357
	358	if (bw == 0 \|\| *tail != '@')
	359	return -EINVAL;
	360
	361	bf = tail + 1;
	362	bo = simple_strtoul(bf, &tail, 0);
	363
	364	if (tail == bf \|\| *tail != '/')
	365	return -EINVAL;
53305928 MH	366	code++;
	367	if (code->op != FETCH_OP_NOP)
	368	return -E2BIG;
	369	*pcode = code;
8ab83f56	370
53305928 MH	371	code->op = FETCH_OP_MOD_BF;
	372	code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
	373	code->rshift = BYTES_TO_BITS(t->size) - bw;
	374	code->basesize = t->size;
8ab83f56 SD	375
	376	return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
	377	}
	378
	379	/* String length checking wrapper */
d00bbea9	380	static int traceprobe_parse_probe_arg_body(char arg, ssize_t size,
a1303af5	381	struct probe_arg *parg, unsigned int flags)
8ab83f56	382	{
40b53b77 MH	383	struct fetch_insn code, scode, *tmp = NULL;
	384	char t, t2;
	385	int ret, len;
8ab83f56 SD	386
	387	if (strlen(arg) > MAX_ARGSTR_LEN) {
	388	pr_info("Argument is too long.: %s\n", arg);
	389	return -ENOSPC;
	390	}
	391	parg->comm = kstrdup(arg, GFP_KERNEL);
	392	if (!parg->comm) {
	393	pr_info("Failed to allocate memory for command '%s'.\n", arg);
	394	return -ENOMEM;
	395	}
40b53b77	396	t = strchr(arg, ':');
8ab83f56	397	if (t) {
40b53b77 MH	398	*t = '\0';
	399	t2 = strchr(++t, '[');
	400	if (t2) {
	401	*t2 = '\0';
	402	parg->count = simple_strtoul(t2 + 1, &t2, 0);
	403	if (strcmp(t2, "]") \|\| parg->count == 0)
	404	return -EINVAL;
	405	if (parg->count > MAX_ARRAY_LEN)
	406	return -E2BIG;
	407	}
8ab83f56	408	}
35abb67d OS	409	/*
	410	* The default type of $comm should be "string", and it can't be
	411	* dereferenced.
	412	*/
	413	if (!t && strcmp(arg, "$comm") == 0)
40b53b77 MH	414	parg->type = find_fetch_type("string");
	415	else
	416	parg->type = find_fetch_type(t);
8ab83f56 SD	417	if (!parg->type) {
	418	pr_info("Unsupported type: %s\n", t);
	419	return -EINVAL;
	420	}
	421	parg->offset = *size;
40b53b77 MH	422	size += parg->type->size (parg->count ?: 1);
	423
	424	if (parg->count) {
	425	len = strlen(parg->type->fmttype) + 6;
	426	parg->fmt = kmalloc(len, GFP_KERNEL);
	427	if (!parg->fmt)
	428	return -ENOMEM;
	429	snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
	430	parg->count);
	431	}
8ab83f56	432
53305928 MH	433	code = tmp = kzalloc(sizeof(code) FETCH_INSN_MAX, GFP_KERNEL);
	434	if (!code)
	435	return -ENOMEM;
	436	code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
	437
	438	ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
a1303af5	439	flags);
53305928 MH	440	if (ret)
	441	goto fail;
	442
	443	/* Store operation */
	444	if (!strcmp(parg->type->name, "string")) {
	445	if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM &&
	446	code->op != FETCH_OP_COMM) {
	447	pr_info("string only accepts memory or address.\n");
	448	ret = -EINVAL;
	449	goto fail;
	450	}
40b53b77 MH	451	if (code->op != FETCH_OP_DEREF \|\| parg->count) {
	452	/*
	453	* IMM and COMM is pointing actual address, those must
	454	* be kept, and if parg->count != 0, this is an array
	455	* of string pointers instead of string address itself.
	456	*/
53305928	457	code++;
40b53b77 MH	458	if (code->op != FETCH_OP_NOP) {
	459	ret = -E2BIG;
	460	goto fail;
	461	}
	462	}
53305928	463	code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */
40b53b77	464	code->size = parg->type->size;
53305928 MH	465	parg->dynamic = true;
	466	} else if (code->op == FETCH_OP_DEREF) {
	467	code->op = FETCH_OP_ST_MEM;
	468	code->size = parg->type->size;
	469	} else {
	470	code++;
	471	if (code->op != FETCH_OP_NOP) {
	472	ret = -E2BIG;
	473	goto fail;
	474	}
	475	code->op = FETCH_OP_ST_RAW;
	476	code->size = parg->type->size;
	477	}
40b53b77	478	scode = code;
53305928 MH	479	/* Modify operation */
	480	if (t != NULL) {
	481	ret = __parse_bitfield_probe_arg(t, parg->type, &code);
	482	if (ret)
	483	goto fail;
8ab83f56	484	}
40b53b77 MH	485	/* Loop(Array) operation */
	486	if (parg->count) {
	487	if (scode->op != FETCH_OP_ST_MEM &&
	488	scode->op != FETCH_OP_ST_STRING) {
	489	pr_info("array only accepts memory or address\n");
	490	ret = -EINVAL;
	491	goto fail;
	492	}
	493	code++;
	494	if (code->op != FETCH_OP_NOP) {
	495	ret = -E2BIG;
	496	goto fail;
	497	}
	498	code->op = FETCH_OP_LP_ARRAY;
	499	code->param = parg->count;
	500	}
53305928 MH	501	code++;
	502	code->op = FETCH_OP_END;
	503
	504	/* Shrink down the code buffer */
	505	parg->code = kzalloc(sizeof(code) (code - tmp + 1), GFP_KERNEL);
	506	if (!parg->code)
	507	ret = -ENOMEM;
	508	else
	509	memcpy(parg->code, tmp, sizeof(code) (code - tmp + 1));
	510
	511	fail:
a6682814 MH	512	if (ret) {
	513	for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
	514	if (code->op == FETCH_NOP_SYMBOL)
	515	kfree(code->data);
	516	}
53305928	517	kfree(tmp);
8ab83f56 SD	518
	519	return ret;
	520	}
	521
	522	/* Return 1 if name is reserved or already used by another argument */
d00bbea9 MH	523	static int traceprobe_conflict_field_name(const char *name,
d00bbea9 MH	524	struct probe_arg *args, int narg)
8ab83f56 SD	525	{
	526	int i;
	527
	528	for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
	529	if (strcmp(reserved_field_names[i], name) == 0)
	530	return 1;
	531
	532	for (i = 0; i < narg; i++)
	533	if (strcmp(args[i].name, name) == 0)
	534	return 1;
	535
	536	return 0;
	537	}
	538
d00bbea9 MH	539	int traceprobe_parse_probe_arg(struct trace_probe tp, int i, char arg,
	540	unsigned int flags)
	541	{
	542	struct probe_arg *parg = &tp->args[i];
	543	char *body;
	544	int ret;
	545
	546	/* Increment count for freeing args in error case */
	547	tp->nr_args++;
	548
	549	body = strchr(arg, '=');
	550	if (body) {
	551	parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
	552	body++;
	553	} else {
	554	/* If argument name is omitted, set "argN" */
	555	parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
	556	body = arg;
	557	}
	558	if (!parg->name)
	559	return -ENOMEM;
	560
	561	if (!is_good_name(parg->name)) {
	562	pr_info("Invalid argument[%d] name: %s\n",
	563	i, parg->name);
	564	return -EINVAL;
	565	}
	566
	567	if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
	568	pr_info("Argument[%d]: '%s' conflicts with another field.\n",
	569	i, parg->name);
	570	return -EINVAL;
	571	}
	572
	573	/* Parse fetch argument */
	574	ret = traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags);
	575	if (ret)
	576	pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
	577	return ret;
	578	}
	579
8ab83f56 SD	580	void traceprobe_free_probe_arg(struct probe_arg *arg)
8ab83f56 SD	581	{
a6682814 MH	582	struct fetch_insn *code = arg->code;
	583
	584	while (code && code->op != FETCH_OP_END) {
	585	if (code->op == FETCH_NOP_SYMBOL)
	586	kfree(code->data);
	587	code++;
	588	}
53305928	589	kfree(arg->code);
8ab83f56 SD	590	kfree(arg->name);
8ab83f56 SD	591	kfree(arg->comm);
40b53b77	592	kfree(arg->fmt);
8ab83f56 SD	593	}
8ab83f56 SD	594
a6682814 MH	595	int traceprobe_update_arg(struct probe_arg *arg)
	596	{
	597	struct fetch_insn *code = arg->code;
	598	long offset;
	599	char *tmp;
	600	char c;
	601	int ret = 0;
	602
	603	while (code && code->op != FETCH_OP_END) {
	604	if (code->op == FETCH_NOP_SYMBOL) {
	605	if (code[1].op != FETCH_OP_IMM)
	606	return -EINVAL;
	607
ee474b81	608	tmp = strpbrk(code->data, "+-");
a6682814 MH	609	if (tmp)
	610	c = *tmp;
	611	ret = traceprobe_split_symbol_offset(code->data,
	612	&offset);
	613	if (ret)
	614	return ret;
	615
	616	code[1].immediate =
	617	(unsigned long)kallsyms_lookup_name(code->data);
	618	if (tmp)
	619	*tmp = c;
	620	if (!code[1].immediate)
	621	return -ENOENT;
	622	code[1].immediate += offset;
	623	}
	624	code++;
	625	}
	626	return 0;
	627	}
	628
40b53b77 MH	629	/* When len=0, we just calculate the needed length */
40b53b77 MH	630	#define LEN_OR_ZERO (len ? len - pos : 0)
5bf652aa NK	631	static int __set_print_fmt(struct trace_probe tp, char buf, int len,
	632	bool is_return)
	633	{
40b53b77 MH	634	struct probe_arg *parg;
40b53b77 MH	635	int i, j;
5bf652aa	636	int pos = 0;
5bf652aa NK	637	const char fmt, arg;
	638
	639	if (!is_return) {
	640	fmt = "(%lx)";
	641	arg = "REC->" FIELD_STRING_IP;
	642	} else {
	643	fmt = "(%lx <- %lx)";
	644	arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
	645	}
	646
5bf652aa NK	647	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
	648
	649	for (i = 0; i < tp->nr_args; i++) {
40b53b77 MH	650	parg = tp->args + i;
	651	pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
	652	if (parg->count) {
	653	pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
	654	parg->type->fmt);
	655	for (j = 1; j < parg->count; j++)
	656	pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
	657	parg->type->fmt);
	658	pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
	659	} else
	660	pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
	661	parg->type->fmt);
5bf652aa NK	662	}
	663
	664	pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
	665
	666	for (i = 0; i < tp->nr_args; i++) {
40b53b77 MH	667	parg = tp->args + i;
	668	if (parg->count) {
	669	if (strcmp(parg->type->name, "string") == 0)
	670	fmt = ", __get_str(%s[%d])";
	671	else
	672	fmt = ", REC->%s[%d]";
	673	for (j = 0; j < parg->count; j++)
	674	pos += snprintf(buf + pos, LEN_OR_ZERO,
	675	fmt, parg->name, j);
	676	} else {
	677	if (strcmp(parg->type->name, "string") == 0)
	678	fmt = ", __get_str(%s)";
	679	else
	680	fmt = ", REC->%s";
5bf652aa	681	pos += snprintf(buf + pos, LEN_OR_ZERO,
40b53b77 MH	682	fmt, parg->name);
40b53b77 MH	683	}
5bf652aa NK	684	}
5bf652aa NK	685
5bf652aa NK	686	/* return the length of print_fmt */
	687	return pos;
	688	}
40b53b77	689	#undef LEN_OR_ZERO
5bf652aa	690
0a46c854	691	int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
5bf652aa NK	692	{
	693	int len;
	694	char *print_fmt;
	695
	696	/* First: called with 0 length to calculate the needed length */
	697	len = __set_print_fmt(tp, NULL, 0, is_return);
	698	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	699	if (!print_fmt)
	700	return -ENOMEM;
	701
	702	/* Second: actually write the @print_fmt */
	703	__set_print_fmt(tp, print_fmt, len + 1, is_return);
	704	tp->call.print_fmt = print_fmt;
	705
	706	return 0;
	707	}
eeb07b06 MH	708
	709	int traceprobe_define_arg_fields(struct trace_event_call *event_call,
	710	size_t offset, struct trace_probe *tp)
	711	{
	712	int ret, i;
	713
	714	/* Set argument names as fields */
	715	for (i = 0; i < tp->nr_args; i++) {
	716	struct probe_arg *parg = &tp->args[i];
40b53b77 MH	717	const char *fmt = parg->type->fmttype;
	718	int size = parg->type->size;
	719
	720	if (parg->fmt)
	721	fmt = parg->fmt;
	722	if (parg->count)
	723	size *= parg->count;
	724	ret = trace_define_field(event_call, fmt, parg->name,
	725	offset + parg->offset, size,
eeb07b06 MH	726	parg->type->is_signed,
	727	FILTER_OTHER);
	728	if (ret)
	729	return ret;
	730	}
	731	return 0;
	732	}