VisionFive2 Linux kernel

diff --git a/fs/fs_parser.c b/fs/fs_parser.c
new file mode 100644
index 000000000000..842e8f749db6
--- /dev/null
+++ b/fs/fs_parser.c
@@ -0,0 +1,447 @@
+/* Filesystem parameter parser.
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/export.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/namei.h>
+#include "internal.h"
+
+static const struct constant_table bool_names[] = {
+	{ "0",		false },
+	{ "1",		true },
+	{ "false",	false },
+	{ "no",		false },
+	{ "true",	true },
+	{ "yes",	true },
+};
+
+/**
+ * lookup_constant - Look up a constant by name in an ordered table
+ * @tbl: The table of constants to search.
+ * @tbl_size: The size of the table.
+ * @name: The name to look up.
+ * @not_found: The value to return if the name is not found.
+ */
+int __lookup_constant(const struct constant_table *tbl, size_t tbl_size,
+		      const char *name, int not_found)
+{
+	unsigned int i;
+
+	for (i = 0; i < tbl_size; i++)
+		if (strcmp(name, tbl[i].name) == 0)
+			return tbl[i].value;
+
+	return not_found;
+}
+EXPORT_SYMBOL(__lookup_constant);
+
+static const struct fs_parameter_spec *fs_lookup_key(
+	const struct fs_parameter_description *desc,
+	const char *name)
+{
+	const struct fs_parameter_spec *p;
+
+	if (!desc->specs)
+		return NULL;
+
+	for (p = desc->specs; p->name; p++)
+		if (strcmp(p->name, name) == 0)
+			return p;
+
+	return NULL;
+}
+
+/*
+ * fs_parse - Parse a filesystem configuration parameter
+ * @fc: The filesystem context to log errors through.
+ * @desc: The parameter description to use.
+ * @param: The parameter.
+ * @result: Where to place the result of the parse
+ *
+ * Parse a filesystem configuration parameter and attempt a conversion for a
+ * simple parameter for which this is requested.  If successful, the determined
+ * parameter ID is placed into @result->key, the desired type is indicated in
+ * @result->t and any converted value is placed into an appropriate member of
+ * the union in @result.
+ *
+ * The function returns the parameter number if the parameter was matched,
+ * -ENOPARAM if it wasn't matched and @desc->ignore_unknown indicated that
+ * unknown parameters are okay and -EINVAL if there was a conversion issue or
+ * the parameter wasn't recognised and unknowns aren't okay.
+ */
+int fs_parse(struct fs_context *fc,
+	     const struct fs_parameter_description *desc,
+	     struct fs_parameter *param,
+	     struct fs_parse_result *result)
+{
+	const struct fs_parameter_spec *p;
+	const struct fs_parameter_enum *e;
+	int ret = -ENOPARAM, b;
+
+	result->has_value = !!param->string;
+	result->negated = false;
+	result->uint_64 = 0;
+
+	p = fs_lookup_key(desc, param->key);
+	if (!p) {
+		/* If we didn't find something that looks like "noxxx", see if
+		 * "xxx" takes the "no"-form negative - but only if there
+		 * wasn't an value.
+		 */
+		if (result->has_value)
+			goto unknown_parameter;
+		if (param->key[0] != 'n' || param->key[1] != 'o' || !param->key[2])
+			goto unknown_parameter;
+
+		p = fs_lookup_key(desc, param->key + 2);
+		if (!p)
+			goto unknown_parameter;
+		if (!(p->flags & fs_param_neg_with_no))
+			goto unknown_parameter;
+		result->boolean = false;
+		result->negated = true;
+	}
+
+	if (p->flags & fs_param_deprecated)
+		warnf(fc, "%s: Deprecated parameter '%s'",
+		      desc->name, param->key);
+
+	if (result->negated)
+		goto okay;
+
+	/* Certain parameter types only take a string and convert it. */
+	switch (p->type) {
+	case __fs_param_wasnt_defined:
+		return -EINVAL;
+	case fs_param_is_u32:
+	case fs_param_is_u32_octal:
+	case fs_param_is_u32_hex:
+	case fs_param_is_s32:
+	case fs_param_is_u64:
+	case fs_param_is_enum:
+	case fs_param_is_string:
+		if (param->type != fs_value_is_string)
+			goto bad_value;
+		if (!result->has_value) {
+			if (p->flags & fs_param_v_optional)
+				goto okay;
+			goto bad_value;
+		}
+		/* Fall through */
+	default:
+		break;
+	}
+
+	/* Try to turn the type we were given into the type desired by the
+	 * parameter and give an error if we can't.
+	 */
+	switch (p->type) {
+	case fs_param_is_flag:
+		if (param->type != fs_value_is_flag &&
+		    (param->type != fs_value_is_string || result->has_value))
+			return invalf(fc, "%s: Unexpected value for '%s'",
+				      desc->name, param->key);
+		result->boolean = true;
+		goto okay;
+
+	case fs_param_is_bool:
+		switch (param->type) {
+		case fs_value_is_flag:
+			result->boolean = true;
+			goto okay;
+		case fs_value_is_string:
+			if (param->size == 0) {
+				result->boolean = true;
+				goto okay;
+			}
+			b = lookup_constant(bool_names, param->string, -1);
+			if (b == -1)
+				goto bad_value;
+			result->boolean = b;
+			goto okay;
+		default:
+			goto bad_value;
+		}
+
+	case fs_param_is_u32:
+		ret = kstrtouint(param->string, 0, &result->uint_32);
+		goto maybe_okay;
+	case fs_param_is_u32_octal:
+		ret = kstrtouint(param->string, 8, &result->uint_32);
+		goto maybe_okay;
+	case fs_param_is_u32_hex:
+		ret = kstrtouint(param->string, 16, &result->uint_32);
+		goto maybe_okay;
+	case fs_param_is_s32:
+		ret = kstrtoint(param->string, 0, &result->int_32);
+		goto maybe_okay;
+	case fs_param_is_u64:
+		ret = kstrtoull(param->string, 0, &result->uint_64);
+		goto maybe_okay;
+
+	case fs_param_is_enum:
+		for (e = desc->enums; e->name[0]; e++) {
+			if (e->opt == p->opt &&
+			    strcmp(e->name, param->string) == 0) {
+				result->uint_32 = e->value;
+				goto okay;
+			}
+		}
+		goto bad_value;
+
+	case fs_param_is_string:
+		goto okay;
+	case fs_param_is_blob:
+		if (param->type != fs_value_is_blob)
+			goto bad_value;
+		goto okay;
+
+	case fs_param_is_fd: {
+		if (param->type != fs_value_is_file)
+			goto bad_value;
+		goto okay;
+	}
+
+	case fs_param_is_blockdev:
+	case fs_param_is_path:
+		goto okay;
+	default:
+		BUG();
+	}
+
+maybe_okay:
+	if (ret < 0)
+		goto bad_value;
+okay:
+	return p->opt;
+
+bad_value:
+	return invalf(fc, "%s: Bad value for '%s'", desc->name, param->key);
+unknown_parameter:
+	return -ENOPARAM;
+}
+EXPORT_SYMBOL(fs_parse);
+
+/**
+ * fs_lookup_param - Look up a path referred to by a parameter
+ * @fc: The filesystem context to log errors through.
+ * @param: The parameter.
+ * @want_bdev: T if want a blockdev
+ * @_path: The result of the lookup
+ */
+int fs_lookup_param(struct fs_context *fc,
+		    struct fs_parameter *param,
+		    bool want_bdev,
+		    struct path *_path)
+{
+	struct filename *f;
+	unsigned int flags = 0;
+	bool put_f;
+	int ret;
+
+	switch (param->type) {
+	case fs_value_is_string:
+		f = getname_kernel(param->string);
+		if (IS_ERR(f))
+			return PTR_ERR(f);
+		put_f = true;
+		break;
+	case fs_value_is_filename_empty:
+		flags = LOOKUP_EMPTY;
+		/* Fall through */
+	case fs_value_is_filename:
+		f = param->name;
+		put_f = false;
+		break;
+	default:
+		return invalf(fc, "%s: not usable as path", param->key);
+	}
+
+	ret = filename_lookup(param->dirfd, f, flags, _path, NULL);
+	if (ret < 0) {
+		errorf(fc, "%s: Lookup failure for '%s'", param->key, f->name);
+		goto out;
+	}
+
+	if (want_bdev &&
+	    !S_ISBLK(d_backing_inode(_path->dentry)->i_mode)) {
+		path_put(_path);
+		_path->dentry = NULL;
+		_path->mnt = NULL;
+		errorf(fc, "%s: Non-blockdev passed as '%s'",
+		       param->key, f->name);
+		ret = -ENOTBLK;
+	}
+
+out:
+	if (put_f)
+		putname(f);
+	return ret;
+}
+EXPORT_SYMBOL(fs_lookup_param);
+
+#ifdef CONFIG_VALIDATE_FS_PARSER
+/**
+ * validate_constant_table - Validate a constant table
+ * @name: Name to use in reporting
+ * @tbl: The constant table to validate.
+ * @tbl_size: The size of the table.
+ * @low: The lowest permissible value.
+ * @high: The highest permissible value.
+ * @special: One special permissible value outside of the range.
+ */
+bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size,
+			     int low, int high, int special)
+{
+	size_t i;
+	bool good = true;
+
+	if (tbl_size == 0) {
+		pr_warn("VALIDATE C-TBL: Empty\n");
+		return true;
+	}
+
+	for (i = 0; i < tbl_size; i++) {
+		if (!tbl[i].name) {
+			pr_err("VALIDATE C-TBL[%zu]: Null\n", i);
+			good = false;
+		} else if (i > 0 && tbl[i - 1].name) {
+			int c = strcmp(tbl[i-1].name, tbl[i].name);
+
+			if (c == 0) {
+				pr_err("VALIDATE C-TBL[%zu]: Duplicate %s\n",
+				       i, tbl[i].name);
+				good = false;
+			}
+			if (c > 0) {
+				pr_err("VALIDATE C-TBL[%zu]: Missorted %s>=%s\n",
+				       i, tbl[i-1].name, tbl[i].name);
+				good = false;
+			}
+		}
+
+		if (tbl[i].value != special &&
+		    (tbl[i].value < low || tbl[i].value > high)) {
+			pr_err("VALIDATE C-TBL[%zu]: %s->%d const out of range (%d-%d)\n",
+			       i, tbl[i].name, tbl[i].value, low, high);
+			good = false;
+		}
+	}
+
+	return good;
+}
+
+/**
+ * fs_validate_description - Validate a parameter description
+ * @desc: The parameter description to validate.
+ */
+bool fs_validate_description(const struct fs_parameter_description *desc)
+{
+	const struct fs_parameter_spec *param, *p2;
+	const struct fs_parameter_enum *e;
+	const char *name = desc->name;
+	unsigned int nr_params = 0;
+	bool good = true, enums = false;
+
+	pr_notice("*** VALIDATE %s ***\n", name);
+
+	if (!name[0]) {
+		pr_err("VALIDATE Parser: No name\n");
+		name = "Unknown";
+		good = false;
+	}
+
+	if (desc->specs) {
+		for (param = desc->specs; param->name; param++) {
+			enum fs_parameter_type t = param->type;
+
+			/* Check that the type is in range */
+			if (t == __fs_param_wasnt_defined ||
+			    t >= nr__fs_parameter_type) {
+				pr_err("VALIDATE %s: PARAM[%s] Bad type %u\n",
+				       name, param->name, t);
+				good = false;
+			} else if (t == fs_param_is_enum) {
+				enums = true;
+			}
+
+			/* Check for duplicate parameter names */
+			for (p2 = desc->specs; p2 < param; p2++) {
+				if (strcmp(param->name, p2->name) == 0) {
+					pr_err("VALIDATE %s: PARAM[%s]: Duplicate\n",
+					       name, param->name);
+					good = false;
+				}
+			}
+		}
+
+		nr_params = param - desc->specs;
+	}
+
+	if (desc->enums) {
+		if (!nr_params) {
+			pr_err("VALIDATE %s: Enum table but no parameters\n",
+			       name);
+			good = false;
+			goto no_enums;
+		}
+		if (!enums) {
+			pr_err("VALIDATE %s: Enum table but no enum-type values\n",
+			       name);
+			good = false;
+			goto no_enums;
+		}
+
+		for (e = desc->enums; e->name[0]; e++) {
+			/* Check that all entries in the enum table have at
+			 * least one parameter that uses them.
+			 */
+			for (param = desc->specs; param->name; param++) {
+				if (param->opt == e->opt &&
+				    param->type != fs_param_is_enum) {
+					pr_err("VALIDATE %s: e[%lu] enum val for %s\n",
+					       name, e - desc->enums, param->name);
+					good = false;
+				}
+			}
+		}
+
+		/* Check that all enum-type parameters have at least one enum
+		 * value in the enum table.
+		 */
+		for (param = desc->specs; param->name; param++) {
+			if (param->type != fs_param_is_enum)
+				continue;
+			for (e = desc->enums; e->name[0]; e++)
+				if (e->opt == param->opt)
+					break;
+			if (!e->name[0]) {
+				pr_err("VALIDATE %s: PARAM[%s] enum with no values\n",
+				       name, param->name);
+				good = false;
+			}
+		}
+	} else {
+		if (enums) {
+			pr_err("VALIDATE %s: enum-type values, but no enum table\n",
+			       name);
+			good = false;
+			goto no_enums;
+		}
+	}
+
+no_enums:
+	return good;
+}
+#endif /* CONFIG_VALIDATE_FS_PARSER */