// 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;	int len; 	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);		if (!is_good_name(buf)) {			pr_info("Group name must follow the same rules as C identifiers\n");			return -EINVAL;		}		*pgroup = buf;		*pevent = slash + 1;		event = *pevent;	}	len = strlen(event);	if (len == 0) {		pr_info("Event name is not specified\n");		return -EINVAL;	} else if (len > MAX_EVENT_NAME_LEN) {		pr_info("Event name is too long\n");		return -E2BIG;	}	if (!is_good_name(event)) {		pr_info("Event name must follow the same rules as C identifiers\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 intparse_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) {

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