[linux-2.6-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"

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;
}

#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)
{
	int ret = 0;
	unsigned long param;

	if (strcmp(arg, "retval") == 0) {
		if (flags & TPARG_FL_RETURN)
			code->op = FETCH_OP_RETVAL;
		else
			ret = -EINVAL;
	} else if (strncmp(arg, "stack", 5) == 0) {
		if (arg[5] == '\0') {
			code->op = FETCH_OP_STACKP;
		} else if (isdigit(arg[5])) {
			ret = kstrtoul(arg + 5, 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)) &&
		   strncmp(arg, "arg", 3) == 0) {
		if (!isdigit(arg[3]))
			return -EINVAL;
		ret = kstrtoul(arg + 3, 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. */
	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 */
int traceprobe_parse_probe_arg(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 */
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_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
	16	const char *reserved_field_names[] = {
	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
	157	#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
	158
	159	static int parse_probe_vars(char arg, const struct fetch_type t,
a1303af5	160	struct fetch_insn *code, unsigned int flags)
8ab83f56 SD	161	{
	162	int ret = 0;
	163	unsigned long param;
	164
	165	if (strcmp(arg, "retval") == 0) {
a1303af5	166	if (flags & TPARG_FL_RETURN)
53305928	167	code->op = FETCH_OP_RETVAL;
8ab83f56 SD	168	else
	169	ret = -EINVAL;
	170	} else if (strncmp(arg, "stack", 5) == 0) {
	171	if (arg[5] == '\0') {
53305928	172	code->op = FETCH_OP_STACKP;
8ab83f56	173	} else if (isdigit(arg[5])) {
bcd83ea6	174	ret = kstrtoul(arg + 5, 10, &param);
a1303af5 MH	175	if (ret \|\| ((flags & TPARG_FL_KERNEL) &&
a1303af5 MH	176	param > PARAM_MAX_STACK))
8ab83f56 SD	177	ret = -EINVAL;
8ab83f56 SD	178	else {
53305928 MH	179	code->op = FETCH_OP_STACK;
53305928 MH	180	code->param = (unsigned int)param;
8ab83f56 SD	181	}
	182	} else
	183	ret = -EINVAL;
35abb67d	184	} else if (strcmp(arg, "comm") == 0) {
53305928	185	code->op = FETCH_OP_COMM;
a1303af5 MH	186	#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
	187	} else if (((flags & TPARG_FL_MASK) ==
	188	(TPARG_FL_KERNEL \| TPARG_FL_FENTRY)) &&
	189	strncmp(arg, "arg", 3) == 0) {
	190	if (!isdigit(arg[3]))
	191	return -EINVAL;
	192	ret = kstrtoul(arg + 3, 10, &param);
	193	if (ret \|\| !param \|\| param > PARAM_MAX_STACK)
	194	return -EINVAL;
	195	code->op = FETCH_OP_ARG;
	196	code->param = (unsigned int)param - 1;
	197	#endif
8ab83f56 SD	198	} else
	199	ret = -EINVAL;
	200
	201	return ret;
	202	}
	203
	204	/* Recursive argument parser */
53305928 MH	205	static int
	206	parse_probe_arg(char arg, const struct fetch_type type,
	207	struct fetch_insn *pcode, struct fetch_insn end,
a1303af5	208	unsigned int flags)
8ab83f56	209	{
53305928	210	struct fetch_insn code = pcode;
8ab83f56	211	unsigned long param;
bf173ca9	212	long offset = 0;
8ab83f56	213	char *tmp;
34fee3a1	214	int ret = 0;
8ab83f56	215
8ab83f56 SD	216	switch (arg[0]) {
8ab83f56 SD	217	case '$':
a1303af5	218	ret = parse_probe_vars(arg + 1, type, code, flags);
8ab83f56 SD	219	break;
	220
	221	case '%': /* named register */
	222	ret = regs_query_register_offset(arg + 1);
	223	if (ret >= 0) {
53305928 MH	224	code->op = FETCH_OP_REG;
53305928 MH	225	code->param = (unsigned int)ret;
8ab83f56 SD	226	ret = 0;
	227	}
	228	break;
	229
b7e0bf34	230	case '@': /* memory, file-offset or symbol */
8ab83f56	231	if (isdigit(arg[1])) {
bcd83ea6	232	ret = kstrtoul(arg + 1, 0, &param);
8ab83f56 SD	233	if (ret)
8ab83f56 SD	234	break;
53305928 MH	235	/* load address */
	236	code->op = FETCH_OP_IMM;
	237	code->immediate = param;
b7e0bf34 NK	238	} else if (arg[1] == '+') {
b7e0bf34 NK	239	/* kprobes don't support file offsets */
a1303af5	240	if (flags & TPARG_FL_KERNEL)
b7e0bf34 NK	241	return -EINVAL;
	242
	243	ret = kstrtol(arg + 2, 0, &offset);
	244	if (ret)
	245	break;
	246
53305928 MH	247	code->op = FETCH_OP_FOFFS;
53305928 MH	248	code->immediate = (unsigned long)offset; // imm64?
8ab83f56	249	} else {
b079d374	250	/* uprobes don't support symbols */
a1303af5	251	if (!(flags & TPARG_FL_KERNEL))
b079d374 NK	252	return -EINVAL;
b079d374 NK	253
a6682814 MH	254	/* Preserve symbol for updating */
	255	code->op = FETCH_NOP_SYMBOL;
	256	code->data = kstrdup(arg + 1, GFP_KERNEL);
	257	if (!code->data)
	258	return -ENOMEM;
	259	if (++code == end)
	260	return -E2BIG;
8ab83f56	261
53305928	262	code->op = FETCH_OP_IMM;
a6682814	263	code->immediate = 0;
8ab83f56	264	}
53305928 MH	265	/* These are fetching from memory */
	266	if (++code == end)
	267	return -E2BIG;
	268	*pcode = code;
	269	code->op = FETCH_OP_DEREF;
	270	code->offset = offset;
8ab83f56 SD	271	break;
	272
	273	case '+': /* deref memory */
bcd83ea6	274	arg++; /* Skip '+', because kstrtol() rejects it. */
8ab83f56 SD	275	case '-':
	276	tmp = strchr(arg, '(');
	277	if (!tmp)
53305928	278	return -EINVAL;
8ab83f56 SD	279
8ab83f56 SD	280	*tmp = '\0';
bcd83ea6	281	ret = kstrtol(arg, 0, &offset);
8ab83f56 SD	282	if (ret)
	283	break;
	284
	285	arg = tmp + 1;
	286	tmp = strrchr(arg, ')');
	287
	288	if (tmp) {
f451bc89	289	const struct fetch_type *t2 = find_fetch_type(NULL);
8ab83f56	290
8ab83f56	291	*tmp = '\0';
a1303af5	292	ret = parse_probe_arg(arg, t2, &code, end, flags);
8ab83f56	293	if (ret)
53305928 MH	294	break;
	295	if (code->op == FETCH_OP_COMM)
	296	return -EINVAL;
	297	if (++code == end)
	298	return -E2BIG;
	299	*pcode = code;
	300
	301	code->op = FETCH_OP_DEREF;
	302	code->offset = offset;
8ab83f56 SD	303	}
	304	break;
	305	}
53305928 MH	306	if (!ret && code->op == FETCH_OP_NOP) {
53305928 MH	307	/* Parsed, but do not find fetch method */
8ab83f56 SD	308	ret = -EINVAL;
8ab83f56 SD	309	}
8ab83f56 SD	310	return ret;
	311	}
	312
	313	#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
	314
	315	/* Bitfield type needs to be parsed into a fetch function */
	316	static int __parse_bitfield_probe_arg(const char *bf,
	317	const struct fetch_type *t,
53305928	318	struct fetch_insn **pcode)
8ab83f56	319	{
53305928	320	struct fetch_insn code = pcode;
8ab83f56 SD	321	unsigned long bw, bo;
	322	char *tail;
	323
	324	if (*bf != 'b')
	325	return 0;
	326
8ab83f56 SD	327	bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
	328
	329	if (bw == 0 \|\| *tail != '@')
	330	return -EINVAL;
	331
	332	bf = tail + 1;
	333	bo = simple_strtoul(bf, &tail, 0);
	334
	335	if (tail == bf \|\| *tail != '/')
	336	return -EINVAL;
53305928 MH	337	code++;
	338	if (code->op != FETCH_OP_NOP)
	339	return -E2BIG;
	340	*pcode = code;
8ab83f56	341
53305928 MH	342	code->op = FETCH_OP_MOD_BF;
	343	code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
	344	code->rshift = BYTES_TO_BITS(t->size) - bw;
	345	code->basesize = t->size;
8ab83f56 SD	346
	347	return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
	348	}
	349
	350	/* String length checking wrapper */
	351	int traceprobe_parse_probe_arg(char arg, ssize_t size,
a1303af5	352	struct probe_arg *parg, unsigned int flags)
8ab83f56	353	{
40b53b77 MH	354	struct fetch_insn code, scode, *tmp = NULL;
	355	char t, t2;
	356	int ret, len;
8ab83f56 SD	357
	358	if (strlen(arg) > MAX_ARGSTR_LEN) {
	359	pr_info("Argument is too long.: %s\n", arg);
	360	return -ENOSPC;
	361	}
	362	parg->comm = kstrdup(arg, GFP_KERNEL);
	363	if (!parg->comm) {
	364	pr_info("Failed to allocate memory for command '%s'.\n", arg);
	365	return -ENOMEM;
	366	}
40b53b77	367	t = strchr(arg, ':');
8ab83f56	368	if (t) {
40b53b77 MH	369	*t = '\0';
	370	t2 = strchr(++t, '[');
	371	if (t2) {
	372	*t2 = '\0';
	373	parg->count = simple_strtoul(t2 + 1, &t2, 0);
	374	if (strcmp(t2, "]") \|\| parg->count == 0)
	375	return -EINVAL;
	376	if (parg->count > MAX_ARRAY_LEN)
	377	return -E2BIG;
	378	}
8ab83f56	379	}
35abb67d OS	380	/*
	381	* The default type of $comm should be "string", and it can't be
	382	* dereferenced.
	383	*/
	384	if (!t && strcmp(arg, "$comm") == 0)
40b53b77 MH	385	parg->type = find_fetch_type("string");
	386	else
	387	parg->type = find_fetch_type(t);
8ab83f56 SD	388	if (!parg->type) {
	389	pr_info("Unsupported type: %s\n", t);
	390	return -EINVAL;
	391	}
	392	parg->offset = *size;
40b53b77 MH	393	size += parg->type->size (parg->count ?: 1);
	394
	395	if (parg->count) {
	396	len = strlen(parg->type->fmttype) + 6;
	397	parg->fmt = kmalloc(len, GFP_KERNEL);
	398	if (!parg->fmt)
	399	return -ENOMEM;
	400	snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
	401	parg->count);
	402	}
8ab83f56	403
53305928 MH	404	code = tmp = kzalloc(sizeof(code) FETCH_INSN_MAX, GFP_KERNEL);
	405	if (!code)
	406	return -ENOMEM;
	407	code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
	408
	409	ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
a1303af5	410	flags);
53305928 MH	411	if (ret)
	412	goto fail;
	413
	414	/* Store operation */
	415	if (!strcmp(parg->type->name, "string")) {
	416	if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM &&
	417	code->op != FETCH_OP_COMM) {
	418	pr_info("string only accepts memory or address.\n");
	419	ret = -EINVAL;
	420	goto fail;
	421	}
40b53b77 MH	422	if (code->op != FETCH_OP_DEREF \|\| parg->count) {
	423	/*
	424	* IMM and COMM is pointing actual address, those must
	425	* be kept, and if parg->count != 0, this is an array
	426	* of string pointers instead of string address itself.
	427	*/
53305928	428	code++;
40b53b77 MH	429	if (code->op != FETCH_OP_NOP) {
	430	ret = -E2BIG;
	431	goto fail;
	432	}
	433	}
53305928	434	code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */
40b53b77	435	code->size = parg->type->size;
53305928 MH	436	parg->dynamic = true;
	437	} else if (code->op == FETCH_OP_DEREF) {
	438	code->op = FETCH_OP_ST_MEM;
	439	code->size = parg->type->size;
	440	} else {
	441	code++;
	442	if (code->op != FETCH_OP_NOP) {
	443	ret = -E2BIG;
	444	goto fail;
	445	}
	446	code->op = FETCH_OP_ST_RAW;
	447	code->size = parg->type->size;
	448	}
40b53b77	449	scode = code;
53305928 MH	450	/* Modify operation */
	451	if (t != NULL) {
	452	ret = __parse_bitfield_probe_arg(t, parg->type, &code);
	453	if (ret)
	454	goto fail;
8ab83f56	455	}
40b53b77 MH	456	/* Loop(Array) operation */
	457	if (parg->count) {
	458	if (scode->op != FETCH_OP_ST_MEM &&
	459	scode->op != FETCH_OP_ST_STRING) {
	460	pr_info("array only accepts memory or address\n");
	461	ret = -EINVAL;
	462	goto fail;
	463	}
	464	code++;
	465	if (code->op != FETCH_OP_NOP) {
	466	ret = -E2BIG;
	467	goto fail;
	468	}
	469	code->op = FETCH_OP_LP_ARRAY;
	470	code->param = parg->count;
	471	}
53305928 MH	472	code++;
	473	code->op = FETCH_OP_END;
	474
	475	/* Shrink down the code buffer */
	476	parg->code = kzalloc(sizeof(code) (code - tmp + 1), GFP_KERNEL);
	477	if (!parg->code)
	478	ret = -ENOMEM;
	479	else
	480	memcpy(parg->code, tmp, sizeof(code) (code - tmp + 1));
	481
	482	fail:
a6682814 MH	483	if (ret) {
	484	for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
	485	if (code->op == FETCH_NOP_SYMBOL)
	486	kfree(code->data);
	487	}
53305928	488	kfree(tmp);
8ab83f56 SD	489
	490	return ret;
	491	}
	492
	493	/* Return 1 if name is reserved or already used by another argument */
	494	int traceprobe_conflict_field_name(const char *name,
	495	struct probe_arg *args, int narg)
	496	{
	497	int i;
	498
	499	for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
	500	if (strcmp(reserved_field_names[i], name) == 0)
	501	return 1;
	502
	503	for (i = 0; i < narg; i++)
	504	if (strcmp(args[i].name, name) == 0)
	505	return 1;
	506
	507	return 0;
	508	}
	509
8ab83f56 SD	510	void traceprobe_free_probe_arg(struct probe_arg *arg)
8ab83f56 SD	511	{
a6682814 MH	512	struct fetch_insn *code = arg->code;
	513
	514	while (code && code->op != FETCH_OP_END) {
	515	if (code->op == FETCH_NOP_SYMBOL)
	516	kfree(code->data);
	517	code++;
	518	}
53305928	519	kfree(arg->code);
8ab83f56 SD	520	kfree(arg->name);
8ab83f56 SD	521	kfree(arg->comm);
40b53b77	522	kfree(arg->fmt);
8ab83f56 SD	523	}
8ab83f56 SD	524
a6682814 MH	525	int traceprobe_update_arg(struct probe_arg *arg)
	526	{
	527	struct fetch_insn *code = arg->code;
	528	long offset;
	529	char *tmp;
	530	char c;
	531	int ret = 0;
	532
	533	while (code && code->op != FETCH_OP_END) {
	534	if (code->op == FETCH_NOP_SYMBOL) {
	535	if (code[1].op != FETCH_OP_IMM)
	536	return -EINVAL;
	537
ee474b81	538	tmp = strpbrk(code->data, "+-");
a6682814 MH	539	if (tmp)
	540	c = *tmp;
	541	ret = traceprobe_split_symbol_offset(code->data,
	542	&offset);
	543	if (ret)
	544	return ret;
	545
	546	code[1].immediate =
	547	(unsigned long)kallsyms_lookup_name(code->data);
	548	if (tmp)
	549	*tmp = c;
	550	if (!code[1].immediate)
	551	return -ENOENT;
	552	code[1].immediate += offset;
	553	}
	554	code++;
	555	}
	556	return 0;
	557	}
	558
40b53b77 MH	559	/* When len=0, we just calculate the needed length */
40b53b77 MH	560	#define LEN_OR_ZERO (len ? len - pos : 0)
5bf652aa NK	561	static int __set_print_fmt(struct trace_probe tp, char buf, int len,
	562	bool is_return)
	563	{
40b53b77 MH	564	struct probe_arg *parg;
40b53b77 MH	565	int i, j;
5bf652aa	566	int pos = 0;
5bf652aa NK	567	const char fmt, arg;
	568
	569	if (!is_return) {
	570	fmt = "(%lx)";
	571	arg = "REC->" FIELD_STRING_IP;
	572	} else {
	573	fmt = "(%lx <- %lx)";
	574	arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
	575	}
	576
5bf652aa NK	577	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
	578
	579	for (i = 0; i < tp->nr_args; i++) {
40b53b77 MH	580	parg = tp->args + i;
	581	pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
	582	if (parg->count) {
	583	pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
	584	parg->type->fmt);
	585	for (j = 1; j < parg->count; j++)
	586	pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
	587	parg->type->fmt);
	588	pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
	589	} else
	590	pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
	591	parg->type->fmt);
5bf652aa NK	592	}
	593
	594	pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
	595
	596	for (i = 0; i < tp->nr_args; i++) {
40b53b77 MH	597	parg = tp->args + i;
	598	if (parg->count) {
	599	if (strcmp(parg->type->name, "string") == 0)
	600	fmt = ", __get_str(%s[%d])";
	601	else
	602	fmt = ", REC->%s[%d]";
	603	for (j = 0; j < parg->count; j++)
	604	pos += snprintf(buf + pos, LEN_OR_ZERO,
	605	fmt, parg->name, j);
	606	} else {
	607	if (strcmp(parg->type->name, "string") == 0)
	608	fmt = ", __get_str(%s)";
	609	else
	610	fmt = ", REC->%s";
5bf652aa	611	pos += snprintf(buf + pos, LEN_OR_ZERO,
40b53b77 MH	612	fmt, parg->name);
40b53b77 MH	613	}
5bf652aa NK	614	}
5bf652aa NK	615
5bf652aa NK	616	/* return the length of print_fmt */
	617	return pos;
	618	}
40b53b77	619	#undef LEN_OR_ZERO
5bf652aa	620
0a46c854	621	int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
5bf652aa NK	622	{
	623	int len;
	624	char *print_fmt;
	625
	626	/* First: called with 0 length to calculate the needed length */
	627	len = __set_print_fmt(tp, NULL, 0, is_return);
	628	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	629	if (!print_fmt)
	630	return -ENOMEM;
	631
	632	/* Second: actually write the @print_fmt */
	633	__set_print_fmt(tp, print_fmt, len + 1, is_return);
	634	tp->call.print_fmt = print_fmt;
	635
	636	return 0;
	637	}
eeb07b06 MH	638
	639	int traceprobe_define_arg_fields(struct trace_event_call *event_call,
	640	size_t offset, struct trace_probe *tp)
	641	{
	642	int ret, i;
	643
	644	/* Set argument names as fields */
	645	for (i = 0; i < tp->nr_args; i++) {
	646	struct probe_arg *parg = &tp->args[i];
40b53b77 MH	647	const char *fmt = parg->type->fmttype;
	648	int size = parg->type->size;
	649
	650	if (parg->fmt)
	651	fmt = parg->fmt;
	652	if (parg->count)
	653	size *= parg->count;
	654	ret = trace_define_field(event_call, fmt, parg->name,
	655	offset + parg->offset, size,
eeb07b06 MH	656	parg->type->is_signed,
	657	FILTER_OTHER);
	658	if (ret)
	659	return ret;
	660	}
	661	return 0;
	662	}