KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

7 files changed, 2025 insertions, 0 deletions

diff --git a/scripts/genksyms/.gitignore b/scripts/genksyms/.gitignore
new file mode 100644
index 000000000..0b275abf9
--- /dev/null
+++ b/scripts/genksyms/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/genksyms
diff --git a/scripts/genksyms/Makefile b/scripts/genksyms/Makefile
new file mode 100644
index 000000000..4350311fb
--- /dev/null
+++ b/scripts/genksyms/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+
+hostprogs-always-y	+= genksyms
+
+genksyms-objs	:= genksyms.o parse.tab.o lex.lex.o
+
+# -I needed for generated C source to include headers in source tree
+HOSTCFLAGS_parse.tab.o := -I $(src)
+HOSTCFLAGS_lex.lex.o := -I $(src)
+
+# dependencies on generated files need to be listed explicitly
+$(obj)/lex.lex.o: $(obj)/parse.tab.h
diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c
new file mode 100644
index 000000000..83e48670c
--- /dev/null
+++ b/scripts/genksyms/genksyms.c
@@ -0,0 +1,850 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Generate kernel symbol version hashes.
+   Copyright 1996, 1997 Linux International.
+
+   New implementation contributed by Richard Henderson <rth@tamu.edu>
+   Based on original work by Bjorn Ekwall <bj0rn@blox.se>
+
+   This file was part of the Linux modutils 2.4.22: moved back into the
+   kernel sources by Rusty Russell/Kai Germaschewski.
+
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <assert.h>
+#include <stdarg.h>
+#include <getopt.h>
+
+#include <hashtable.h>
+
+#include "genksyms.h"
+/*----------------------------------------------------------------------*/
+
+static HASHTABLE_DEFINE(symbol_hashtable, 1U << 12);
+static FILE *debugfile;
+
+int cur_line = 1;
+char *cur_filename;
+int in_source_file;
+
+static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,
+	   flag_preserve, flag_warnings;
+
+static int errors;
+static int nsyms;
+
+static struct symbol *expansion_trail;
+static struct symbol *visited_symbols;
+
+static const struct {
+	int n;
+	const char *name;
+} symbol_types[] = {
+	[SYM_NORMAL]     = { 0, NULL},
+	[SYM_TYPEDEF]    = {'t', "typedef"},
+	[SYM_ENUM]       = {'e', "enum"},
+	[SYM_STRUCT]     = {'s', "struct"},
+	[SYM_UNION]      = {'u', "union"},
+	[SYM_ENUM_CONST] = {'E', "enum constant"},
+};
+
+static int equal_list(struct string_list *a, struct string_list *b);
+static void print_list(FILE * f, struct string_list *list);
+static struct string_list *concat_list(struct string_list *start, ...);
+static struct string_list *mk_node(const char *string);
+static void print_location(void);
+static void print_type_name(enum symbol_type type, const char *name);
+
+/*----------------------------------------------------------------------*/
+
+static const uint32_t crctab32[] = {
+	0x00000000U, 0x77073096U, 0xee0e612cU, 0x990951baU, 0x076dc419U,
+	0x706af48fU, 0xe963a535U, 0x9e6495a3U, 0x0edb8832U, 0x79dcb8a4U,
+	0xe0d5e91eU, 0x97d2d988U, 0x09b64c2bU, 0x7eb17cbdU, 0xe7b82d07U,
+	0x90bf1d91U, 0x1db71064U, 0x6ab020f2U, 0xf3b97148U, 0x84be41deU,
+	0x1adad47dU, 0x6ddde4ebU, 0xf4d4b551U, 0x83d385c7U, 0x136c9856U,
+	0x646ba8c0U, 0xfd62f97aU, 0x8a65c9ecU, 0x14015c4fU, 0x63066cd9U,
+	0xfa0f3d63U, 0x8d080df5U, 0x3b6e20c8U, 0x4c69105eU, 0xd56041e4U,
+	0xa2677172U, 0x3c03e4d1U, 0x4b04d447U, 0xd20d85fdU, 0xa50ab56bU,
+	0x35b5a8faU, 0x42b2986cU, 0xdbbbc9d6U, 0xacbcf940U, 0x32d86ce3U,
+	0x45df5c75U, 0xdcd60dcfU, 0xabd13d59U, 0x26d930acU, 0x51de003aU,
+	0xc8d75180U, 0xbfd06116U, 0x21b4f4b5U, 0x56b3c423U, 0xcfba9599U,
+	0xb8bda50fU, 0x2802b89eU, 0x5f058808U, 0xc60cd9b2U, 0xb10be924U,
+	0x2f6f7c87U, 0x58684c11U, 0xc1611dabU, 0xb6662d3dU, 0x76dc4190U,
+	0x01db7106U, 0x98d220bcU, 0xefd5102aU, 0x71b18589U, 0x06b6b51fU,
+	0x9fbfe4a5U, 0xe8b8d433U, 0x7807c9a2U, 0x0f00f934U, 0x9609a88eU,
+	0xe10e9818U, 0x7f6a0dbbU, 0x086d3d2dU, 0x91646c97U, 0xe6635c01U,
+	0x6b6b51f4U, 0x1c6c6162U, 0x856530d8U, 0xf262004eU, 0x6c0695edU,
+	0x1b01a57bU, 0x8208f4c1U, 0xf50fc457U, 0x65b0d9c6U, 0x12b7e950U,
+	0x8bbeb8eaU, 0xfcb9887cU, 0x62dd1ddfU, 0x15da2d49U, 0x8cd37cf3U,
+	0xfbd44c65U, 0x4db26158U, 0x3ab551ceU, 0xa3bc0074U, 0xd4bb30e2U,
+	0x4adfa541U, 0x3dd895d7U, 0xa4d1c46dU, 0xd3d6f4fbU, 0x4369e96aU,
+	0x346ed9fcU, 0xad678846U, 0xda60b8d0U, 0x44042d73U, 0x33031de5U,
+	0xaa0a4c5fU, 0xdd0d7cc9U, 0x5005713cU, 0x270241aaU, 0xbe0b1010U,
+	0xc90c2086U, 0x5768b525U, 0x206f85b3U, 0xb966d409U, 0xce61e49fU,
+	0x5edef90eU, 0x29d9c998U, 0xb0d09822U, 0xc7d7a8b4U, 0x59b33d17U,
+	0x2eb40d81U, 0xb7bd5c3bU, 0xc0ba6cadU, 0xedb88320U, 0x9abfb3b6U,
+	0x03b6e20cU, 0x74b1d29aU, 0xead54739U, 0x9dd277afU, 0x04db2615U,
+	0x73dc1683U, 0xe3630b12U, 0x94643b84U, 0x0d6d6a3eU, 0x7a6a5aa8U,
+	0xe40ecf0bU, 0x9309ff9dU, 0x0a00ae27U, 0x7d079eb1U, 0xf00f9344U,
+	0x8708a3d2U, 0x1e01f268U, 0x6906c2feU, 0xf762575dU, 0x806567cbU,
+	0x196c3671U, 0x6e6b06e7U, 0xfed41b76U, 0x89d32be0U, 0x10da7a5aU,
+	0x67dd4accU, 0xf9b9df6fU, 0x8ebeeff9U, 0x17b7be43U, 0x60b08ed5U,
+	0xd6d6a3e8U, 0xa1d1937eU, 0x38d8c2c4U, 0x4fdff252U, 0xd1bb67f1U,
+	0xa6bc5767U, 0x3fb506ddU, 0x48b2364bU, 0xd80d2bdaU, 0xaf0a1b4cU,
+	0x36034af6U, 0x41047a60U, 0xdf60efc3U, 0xa867df55U, 0x316e8eefU,
+	0x4669be79U, 0xcb61b38cU, 0xbc66831aU, 0x256fd2a0U, 0x5268e236U,
+	0xcc0c7795U, 0xbb0b4703U, 0x220216b9U, 0x5505262fU, 0xc5ba3bbeU,
+	0xb2bd0b28U, 0x2bb45a92U, 0x5cb36a04U, 0xc2d7ffa7U, 0xb5d0cf31U,
+	0x2cd99e8bU, 0x5bdeae1dU, 0x9b64c2b0U, 0xec63f226U, 0x756aa39cU,
+	0x026d930aU, 0x9c0906a9U, 0xeb0e363fU, 0x72076785U, 0x05005713U,
+	0x95bf4a82U, 0xe2b87a14U, 0x7bb12baeU, 0x0cb61b38U, 0x92d28e9bU,
+	0xe5d5be0dU, 0x7cdcefb7U, 0x0bdbdf21U, 0x86d3d2d4U, 0xf1d4e242U,
+	0x68ddb3f8U, 0x1fda836eU, 0x81be16cdU, 0xf6b9265bU, 0x6fb077e1U,
+	0x18b74777U, 0x88085ae6U, 0xff0f6a70U, 0x66063bcaU, 0x11010b5cU,
+	0x8f659effU, 0xf862ae69U, 0x616bffd3U, 0x166ccf45U, 0xa00ae278U,
+	0xd70dd2eeU, 0x4e048354U, 0x3903b3c2U, 0xa7672661U, 0xd06016f7U,
+	0x4969474dU, 0x3e6e77dbU, 0xaed16a4aU, 0xd9d65adcU, 0x40df0b66U,
+	0x37d83bf0U, 0xa9bcae53U, 0xdebb9ec5U, 0x47b2cf7fU, 0x30b5ffe9U,
+	0xbdbdf21cU, 0xcabac28aU, 0x53b39330U, 0x24b4a3a6U, 0xbad03605U,
+	0xcdd70693U, 0x54de5729U, 0x23d967bfU, 0xb3667a2eU, 0xc4614ab8U,
+	0x5d681b02U, 0x2a6f2b94U, 0xb40bbe37U, 0xc30c8ea1U, 0x5a05df1bU,
+	0x2d02ef8dU
+};
+
+static uint32_t partial_crc32_one(uint8_t c, uint32_t crc)
+{
+	return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
+}
+
+static uint32_t partial_crc32(const char *s, uint32_t crc)
+{
+	while (*s)
+		crc = partial_crc32_one(*s++, crc);
+	return crc;
+}
+
+static uint32_t crc32(const char *s)
+{
+	return partial_crc32(s, 0xffffffff) ^ 0xffffffff;
+}
+
+/*----------------------------------------------------------------------*/
+
+static enum symbol_type map_to_ns(enum symbol_type t)
+{
+	switch (t) {
+	case SYM_ENUM_CONST:
+	case SYM_NORMAL:
+	case SYM_TYPEDEF:
+		return SYM_NORMAL;
+	case SYM_ENUM:
+	case SYM_STRUCT:
+	case SYM_UNION:
+		return SYM_STRUCT;
+	}
+	return t;
+}
+
+struct symbol *find_symbol(const char *name, enum symbol_type ns, int exact)
+{
+	struct symbol *sym;
+
+	hash_for_each_possible(symbol_hashtable, sym, hnode, crc32(name)) {
+		if (map_to_ns(sym->type) == map_to_ns(ns) &&
+		    strcmp(name, sym->name) == 0 &&
+		    sym->is_declared)
+			break;
+	}
+
+	if (exact && sym && sym->type != ns)
+		return NULL;
+	return sym;
+}
+
+static int is_unknown_symbol(struct symbol *sym)
+{
+	struct string_list *defn;
+
+	return ((sym->type == SYM_STRUCT ||
+		 sym->type == SYM_UNION ||
+		 sym->type == SYM_ENUM) &&
+		(defn = sym->defn)  && defn->tag == SYM_NORMAL &&
+			strcmp(defn->string, "}") == 0 &&
+		(defn = defn->next) && defn->tag == SYM_NORMAL &&
+			strcmp(defn->string, "UNKNOWN") == 0 &&
+		(defn = defn->next) && defn->tag == SYM_NORMAL &&
+			strcmp(defn->string, "{") == 0);
+}
+
+static struct string_list *process_enum(const char *name, enum symbol_type type,
+					struct string_list *defn)
+{
+	/* The parser adds symbols in the order their declaration completes,
+	 * so it is safe to store the value of the previous enum constant in
+	 * a static variable.
+	 */
+	static int enum_counter;
+	static struct string_list *last_enum_expr;
+
+	if (type == SYM_ENUM_CONST) {
+		if (defn) {
+			free_list(last_enum_expr, NULL);
+			last_enum_expr = copy_list_range(defn, NULL);
+			enum_counter = 1;
+		} else {
+			struct string_list *expr;
+			char buf[20];
+
+			snprintf(buf, sizeof(buf), "%d", enum_counter++);
+			if (last_enum_expr) {
+				expr = copy_list_range(last_enum_expr, NULL);
+				defn = concat_list(mk_node("("),
+						   expr,
+						   mk_node(")"),
+						   mk_node("+"),
+						   mk_node(buf), NULL);
+			} else {
+				defn = mk_node(buf);
+			}
+		}
+	} else {
+		free_list(last_enum_expr, NULL);
+		last_enum_expr = NULL;
+		enum_counter = 0;
+		if (!name)
+			/* Anonymous enum definition, nothing more to do */
+			return NULL;
+	}
+
+	return defn;
+}
+
+static struct symbol *__add_symbol(const char *name, enum symbol_type type,
+			    struct string_list *defn, int is_extern,
+			    int is_reference)
+{
+	unsigned long h;
+	struct symbol *sym;
+	enum symbol_status status = STATUS_UNCHANGED;
+
+	if ((type == SYM_ENUM_CONST || type == SYM_ENUM) && !is_reference) {
+		defn = process_enum(name, type, defn);
+		if (defn == NULL)
+			return NULL;
+	}
+
+	h = crc32(name);
+	hash_for_each_possible(symbol_hashtable, sym, hnode, h) {
+		if (map_to_ns(sym->type) != map_to_ns(type) ||
+		    strcmp(name, sym->name))
+			continue;
+
+		if (is_reference) {
+			break;
+		} else if (sym->type == type && equal_list(sym->defn, defn)) {
+			if (!sym->is_declared && sym->is_override) {
+				print_location();
+				print_type_name(type, name);
+				fprintf(stderr, " modversion is unchanged\n");
+			}
+			sym->is_declared = 1;
+		} else if (sym->is_declared) {
+			error_with_pos("redefinition of %s", name);
+		} else if (sym->is_override && flag_preserve) {
+			print_location();
+			fprintf(stderr, "ignoring ");
+			print_type_name(type, name);
+			fprintf(stderr, " modversion change\n");
+			sym->is_declared = 1;
+		} else {
+			status = is_unknown_symbol(sym) ?
+					STATUS_DEFINED : STATUS_MODIFIED;
+			break;
+		}
+		free_list(defn, NULL);
+		return sym;
+	}
+
+	if (sym) {
+		hash_del(&sym->hnode);
+
+		free_list(sym->defn, NULL);
+		free(sym->name);
+		free(sym);
+		--nsyms;
+	}
+
+	sym = xmalloc(sizeof(*sym));
+	sym->name = xstrdup(name);
+	sym->type = type;
+	sym->defn = defn;
+	sym->expansion_trail = NULL;
+	sym->visited = NULL;
+	sym->is_extern = is_extern;
+
+	hash_add(symbol_hashtable, &sym->hnode, h);
+
+	sym->is_declared = !is_reference;
+	sym->status = status;
+	sym->is_override = 0;
+
+	if (flag_debug) {
+		if (symbol_types[type].name)
+			fprintf(debugfile, "Defn for %s %s == <",
+				symbol_types[type].name, name);
+		else
+			fprintf(debugfile, "Defn for type%d %s == <",
+				type, name);
+		if (is_extern)
+			fputs("extern ", debugfile);
+		print_list(debugfile, defn);
+		fputs(">\n", debugfile);
+	}
+
+	++nsyms;
+	return sym;
+}
+
+struct symbol *add_symbol(const char *name, enum symbol_type type,
+			  struct string_list *defn, int is_extern)
+{
+	return __add_symbol(name, type, defn, is_extern, 0);
+}
+
+static struct symbol *add_reference_symbol(const char *name, enum symbol_type type,
+				    struct string_list *defn, int is_extern)
+{
+	return __add_symbol(name, type, defn, is_extern, 1);
+}
+
+/*----------------------------------------------------------------------*/
+
+void free_node(struct string_list *node)
+{
+	free(node->string);
+	free(node);
+}
+
+void free_list(struct string_list *s, struct string_list *e)
+{
+	while (s != e) {
+		struct string_list *next = s->next;
+		free_node(s);
+		s = next;
+	}
+}
+
+static struct string_list *mk_node(const char *string)
+{
+	struct string_list *newnode;
+
+	newnode = xmalloc(sizeof(*newnode));
+	newnode->string = xstrdup(string);
+	newnode->tag = SYM_NORMAL;
+	newnode->next = NULL;
+
+	return newnode;
+}
+
+static struct string_list *concat_list(struct string_list *start, ...)
+{
+	va_list ap;
+	struct string_list *n, *n2;
+
+	if (!start)
+		return NULL;
+	for (va_start(ap, start); (n = va_arg(ap, struct string_list *));) {
+		for (n2 = n; n2->next; n2 = n2->next)
+			;
+		n2->next = start;
+		start = n;
+	}
+	va_end(ap);
+	return start;
+}
+
+struct string_list *copy_node(struct string_list *node)
+{
+	struct string_list *newnode;
+
+	newnode = xmalloc(sizeof(*newnode));
+	newnode->string = xstrdup(node->string);
+	newnode->tag = node->tag;
+
+	return newnode;
+}
+
+struct string_list *copy_list_range(struct string_list *start,
+				    struct string_list *end)
+{
+	struct string_list *res, *n;
+
+	if (start == end)
+		return NULL;
+	n = res = copy_node(start);
+	for (start = start->next; start != end; start = start->next) {
+		n->next = copy_node(start);
+		n = n->next;
+	}
+	n->next = NULL;
+	return res;
+}
+
+static int equal_list(struct string_list *a, struct string_list *b)
+{
+	while (a && b) {
+		if (a->tag != b->tag || strcmp(a->string, b->string))
+			return 0;
+		a = a->next;
+		b = b->next;
+	}
+
+	return !a && !b;
+}
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+static struct string_list *read_node(FILE *f)
+{
+	char buffer[256];
+	struct string_list node = {
+		.string = buffer,
+		.tag = SYM_NORMAL };
+	int c, in_string = 0;
+
+	while ((c = fgetc(f)) != EOF) {
+		if (!in_string && c == ' ') {
+			if (node.string == buffer)
+				continue;
+			break;
+		} else if (c == '"') {
+			in_string = !in_string;
+		} else if (c == '\n') {
+			if (node.string == buffer)
+				return NULL;
+			ungetc(c, f);
+			break;
+		}
+		if (node.string >= buffer + sizeof(buffer) - 1) {
+			fprintf(stderr, "Token too long\n");
+			exit(1);
+		}
+		*node.string++ = c;
+	}
+	if (node.string == buffer)
+		return NULL;
+	*node.string = 0;
+	node.string = buffer;
+
+	if (node.string[1] == '#') {
+		size_t n;
+
+		for (n = 0; n < ARRAY_SIZE(symbol_types); n++) {
+			if (node.string[0] == symbol_types[n].n) {
+				node.tag = n;
+				node.string += 2;
+				return copy_node(&node);
+			}
+		}
+		fprintf(stderr, "Unknown type %c\n", node.string[0]);
+		exit(1);
+	}
+	return copy_node(&node);
+}
+
+static void read_reference(FILE *f)
+{
+	while (!feof(f)) {
+		struct string_list *defn = NULL;
+		struct string_list *sym, *def;
+		int is_extern = 0, is_override = 0;
+		struct symbol *subsym;
+
+		sym = read_node(f);
+		if (sym && sym->tag == SYM_NORMAL &&
+		    !strcmp(sym->string, "override")) {
+			is_override = 1;
+			free_node(sym);
+			sym = read_node(f);
+		}
+		if (!sym)
+			continue;
+		def = read_node(f);
+		if (def && def->tag == SYM_NORMAL &&
+		    !strcmp(def->string, "extern")) {
+			is_extern = 1;
+			free_node(def);
+			def = read_node(f);
+		}
+		while (def) {
+			def->next = defn;
+			defn = def;
+			def = read_node(f);
+		}
+		subsym = add_reference_symbol(sym->string, sym->tag,
+					      defn, is_extern);
+		subsym->is_override = is_override;
+		free_node(sym);
+	}
+}
+
+static void print_node(FILE * f, struct string_list *list)
+{
+	if (symbol_types[list->tag].n) {
+		putc(symbol_types[list->tag].n, f);
+		putc('#', f);
+	}
+	fputs(list->string, f);
+}
+
+static void print_list(FILE * f, struct string_list *list)
+{
+	struct string_list **e, **b;
+	struct string_list *tmp, **tmp2;
+	int elem = 1;
+
+	if (list == NULL) {
+		fputs("(nil)", f);
+		return;
+	}
+
+	tmp = list;
+	while ((tmp = tmp->next) != NULL)
+		elem++;
+
+	b = alloca(elem * sizeof(*e));
+	e = b + elem;
+	tmp2 = e - 1;
+
+	(*tmp2--) = list;
+	while ((list = list->next) != NULL)
+		*(tmp2--) = list;
+
+	while (b != e) {
+		print_node(f, *b++);
+		putc(' ', f);
+	}
+}
+
+static uint32_t expand_and_crc_sym(struct symbol *sym, uint32_t crc)
+{
+	struct string_list *list = sym->defn;
+	struct string_list **e, **b;
+	struct string_list *tmp, **tmp2;
+	int elem = 1;
+
+	if (!list)
+		return crc;
+
+	tmp = list;
+	while ((tmp = tmp->next) != NULL)
+		elem++;
+
+	b = alloca(elem * sizeof(*e));
+	e = b + elem;
+	tmp2 = e - 1;
+
+	*(tmp2--) = list;
+	while ((list = list->next) != NULL)
+		*(tmp2--) = list;
+
+	while (b != e) {
+		struct string_list *cur;
+		struct symbol *subsym;
+
+		cur = *(b++);
+		switch (cur->tag) {
+		case SYM_NORMAL:
+			if (flag_dump_defs)
+				fprintf(debugfile, "%s ", cur->string);
+			crc = partial_crc32(cur->string, crc);
+			crc = partial_crc32_one(' ', crc);
+			break;
+
+		case SYM_ENUM_CONST:
+		case SYM_TYPEDEF:
+			subsym = find_symbol(cur->string, cur->tag, 0);
+			/* FIXME: Bad reference files can segfault here. */
+			if (subsym->expansion_trail) {
+				if (flag_dump_defs)
+					fprintf(debugfile, "%s ", cur->string);
+				crc = partial_crc32(cur->string, crc);
+				crc = partial_crc32_one(' ', crc);
+			} else {
+				subsym->expansion_trail = expansion_trail;
+				expansion_trail = subsym;
+				crc = expand_and_crc_sym(subsym, crc);
+			}
+			break;
+
+		case SYM_STRUCT:
+		case SYM_UNION:
+		case SYM_ENUM:
+			subsym = find_symbol(cur->string, cur->tag, 0);
+			if (!subsym) {
+				struct string_list *n;
+
+				error_with_pos("expand undefined %s %s",
+					       symbol_types[cur->tag].name,
+					       cur->string);
+				n = concat_list(mk_node
+						(symbol_types[cur->tag].name),
+						mk_node(cur->string),
+						mk_node("{"),
+						mk_node("UNKNOWN"),
+						mk_node("}"), NULL);
+				subsym =
+				    add_symbol(cur->string, cur->tag, n, 0);
+			}
+			if (subsym->expansion_trail) {
+				if (flag_dump_defs) {
+					fprintf(debugfile, "%s %s ",
+						symbol_types[cur->tag].name,
+						cur->string);
+				}
+
+				crc = partial_crc32(symbol_types[cur->tag].name,
+						    crc);
+				crc = partial_crc32_one(' ', crc);
+				crc = partial_crc32(cur->string, crc);
+				crc = partial_crc32_one(' ', crc);
+			} else {
+				subsym->expansion_trail = expansion_trail;
+				expansion_trail = subsym;
+				crc = expand_and_crc_sym(subsym, crc);
+			}
+			break;
+		}
+	}
+
+	{
+		static struct symbol **end = &visited_symbols;
+
+		if (!sym->visited) {
+			*end = sym;
+			end = &sym->visited;
+			sym->visited = (struct symbol *)-1L;
+		}
+	}
+
+	return crc;
+}
+
+void export_symbol(const char *name)
+{
+	struct symbol *sym;
+	uint32_t crc;
+	int has_changed = 0;
+
+	sym = find_symbol(name, SYM_NORMAL, 0);
+	if (!sym) {
+		error_with_pos("export undefined symbol %s", name);
+		return;
+	}
+
+	if (flag_dump_defs)
+		fprintf(debugfile, "Export %s == <", name);
+
+	expansion_trail = (struct symbol *)-1L;
+
+	sym->expansion_trail = expansion_trail;
+	expansion_trail = sym;
+	crc = expand_and_crc_sym(sym, 0xffffffff) ^ 0xffffffff;
+
+	sym = expansion_trail;
+	while (sym != (struct symbol *)-1L) {
+		struct symbol *n = sym->expansion_trail;
+
+		if (sym->status != STATUS_UNCHANGED) {
+			if (!has_changed) {
+				print_location();
+				fprintf(stderr,
+					"%s: %s: modversion changed because of changes in ",
+					flag_preserve ? "error" : "warning",
+					name);
+			} else {
+				fprintf(stderr, ", ");
+			}
+			print_type_name(sym->type, sym->name);
+			if (sym->status == STATUS_DEFINED)
+				fprintf(stderr, " (became defined)");
+			has_changed = 1;
+			if (flag_preserve)
+				errors++;
+		}
+		sym->expansion_trail = 0;
+		sym = n;
+	}
+	if (has_changed)
+		fprintf(stderr, "\n");
+
+	if (flag_dump_defs)
+		fputs(">\n", debugfile);
+
+	printf("#SYMVER %s 0x%08lx\n", name, (unsigned long)crc);
+}
+
+/*----------------------------------------------------------------------*/
+
+static void print_location(void)
+{
+	fprintf(stderr, "%s:%d: ", cur_filename ? : "<stdin>", cur_line);
+}
+
+static void print_type_name(enum symbol_type type, const char *name)
+{
+	if (symbol_types[type].name)
+		fprintf(stderr, "%s %s", symbol_types[type].name, name);
+	else
+		fprintf(stderr, "%s", name);
+}
+
+void error_with_pos(const char *fmt, ...)
+{
+	va_list args;
+
+	if (flag_warnings) {
+		print_location();
+
+		va_start(args, fmt);
+		vfprintf(stderr, fmt, args);
+		va_end(args);
+		putc('\n', stderr);
+
+		errors++;
+	}
+}
+
+static void genksyms_usage(void)
+{
+	fputs("Usage:\n" "genksyms [-adDTwqhVR] > /path/to/.tmp_obj.ver\n" "\n"
+	      "  -d, --debug           Increment the debug level (repeatable)\n"
+	      "  -D, --dump            Dump expanded symbol defs (for debugging only)\n"
+	      "  -r, --reference file  Read reference symbols from a file\n"
+	      "  -T, --dump-types file Dump expanded types into file\n"
+	      "  -p, --preserve        Preserve reference modversions or fail\n"
+	      "  -w, --warnings        Enable warnings\n"
+	      "  -q, --quiet           Disable warnings (default)\n"
+	      "  -h, --help            Print this message\n"
+	      "  -V, --version         Print the release version\n"
+	      , stderr);
+}
+
+int main(int argc, char **argv)
+{
+	FILE *dumpfile = NULL, *ref_file = NULL;
+	int o;
+
+	struct option long_opts[] = {
+		{"debug", 0, 0, 'd'},
+		{"warnings", 0, 0, 'w'},
+		{"quiet", 0, 0, 'q'},
+		{"dump", 0, 0, 'D'},
+		{"reference", 1, 0, 'r'},
+		{"dump-types", 1, 0, 'T'},
+		{"preserve", 0, 0, 'p'},
+		{"version", 0, 0, 'V'},
+		{"help", 0, 0, 'h'},
+		{0, 0, 0, 0}
+	};
+
+	while ((o = getopt_long(argc, argv, "dwqVDr:T:ph",
+				&long_opts[0], NULL)) != EOF)
+		switch (o) {
+		case 'd':
+			flag_debug++;
+			break;
+		case 'w':
+			flag_warnings = 1;
+			break;
+		case 'q':
+			flag_warnings = 0;
+			break;
+		case 'V':
+			fputs("genksyms version 2.5.60\n", stderr);
+			break;
+		case 'D':
+			flag_dump_defs = 1;
+			break;
+		case 'r':
+			flag_reference = 1;
+			ref_file = fopen(optarg, "r");
+			if (!ref_file) {
+				perror(optarg);
+				return 1;
+			}
+			break;
+		case 'T':
+			flag_dump_types = 1;
+			dumpfile = fopen(optarg, "w");
+			if (!dumpfile) {
+				perror(optarg);
+				return 1;
+			}
+			break;
+		case 'p':
+			flag_preserve = 1;
+			break;
+		case 'h':
+			genksyms_usage();
+			return 0;
+		default:
+			genksyms_usage();
+			return 1;
+		}
+	{
+		extern int yydebug;
+		extern int yy_flex_debug;
+
+		yydebug = (flag_debug > 1);
+		yy_flex_debug = (flag_debug > 2);
+
+		debugfile = stderr;
+		/* setlinebuf(debugfile); */
+	}
+
+	if (flag_reference) {
+		read_reference(ref_file);
+		fclose(ref_file);
+	}
+
+	yyparse();
+
+	if (flag_dump_types && visited_symbols) {
+		while (visited_symbols != (struct symbol *)-1L) {
+			struct symbol *sym = visited_symbols;
+
+			if (sym->is_override)
+				fputs("override ", dumpfile);
+			if (symbol_types[sym->type].n) {
+				putc(symbol_types[sym->type].n, dumpfile);
+				putc('#', dumpfile);
+			}
+			fputs(sym->name, dumpfile);
+			putc(' ', dumpfile);
+			if (sym->is_extern)
+				fputs("extern ", dumpfile);
+			print_list(dumpfile, sym->defn);
+			putc('\n', dumpfile);
+
+			visited_symbols = sym->visited;
+			sym->visited = NULL;
+		}
+	}
+
+	if (flag_debug) {
+		fprintf(debugfile, "Hash table occupancy %d/%zd = %g\n",
+			nsyms, HASH_SIZE(symbol_hashtable),
+			(double)nsyms / HASH_SIZE(symbol_hashtable));
+	}
+
+	if (dumpfile)
+		fclose(dumpfile);
+
+	return errors != 0;
+}
diff --git a/scripts/genksyms/genksyms.h b/scripts/genksyms/genksyms.h
new file mode 100644
index 000000000..0c355075f
--- /dev/null
+++ b/scripts/genksyms/genksyms.h
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Generate kernel symbol version hashes.
+   Copyright 1996, 1997 Linux International.
+
+   New implementation contributed by Richard Henderson <rth@tamu.edu>
+   Based on original work by Bjorn Ekwall <bj0rn@blox.se>
+
+   This file is part of the Linux modutils.
+
+ */
+
+#ifndef MODUTILS_GENKSYMS_H
+#define MODUTILS_GENKSYMS_H 1
+
+#include <stdbool.h>
+#include <stdio.h>
+
+#include <list_types.h>
+
+enum symbol_type {
+	SYM_NORMAL, SYM_TYPEDEF, SYM_ENUM, SYM_STRUCT, SYM_UNION,
+	SYM_ENUM_CONST
+};
+
+enum symbol_status {
+	STATUS_UNCHANGED, STATUS_DEFINED, STATUS_MODIFIED
+};
+
+struct string_list {
+	struct string_list *next;
+	enum symbol_type tag;
+	int in_source_file;
+	char *string;
+};
+
+struct symbol {
+	struct hlist_node hnode;
+	char *name;
+	enum symbol_type type;
+	struct string_list *defn;
+	struct symbol *expansion_trail;
+	struct symbol *visited;
+	int is_extern;
+	int is_declared;
+	enum symbol_status status;
+	int is_override;
+};
+
+typedef struct string_list **yystype;
+#define YYSTYPE yystype
+
+extern int cur_line;
+extern char *cur_filename;
+extern int in_source_file;
+
+struct symbol *find_symbol(const char *name, enum symbol_type ns, int exact);
+struct symbol *add_symbol(const char *name, enum symbol_type type,
+			  struct string_list *defn, int is_extern);
+void export_symbol(const char *);
+
+void free_node(struct string_list *list);
+void free_list(struct string_list *s, struct string_list *e);
+struct string_list *copy_node(struct string_list *);
+struct string_list *copy_list_range(struct string_list *start,
+				    struct string_list *end);
+
+int yylex(void);
+int yyparse(void);
+
+extern bool dont_want_type_specifier;
+
+void error_with_pos(const char *, ...) __attribute__ ((format(printf, 1, 2)));
+
+/*----------------------------------------------------------------------*/
+#define xmalloc(size) ({ void *__ptr = malloc(size);		\
+	if(!__ptr && size != 0) {				\
+		fprintf(stderr, "out of memory\n");		\
+		exit(1);					\
+	}							\
+	__ptr; })
+#define xstrdup(str)  ({ char *__str = strdup(str);		\
+	if (!__str) {						\
+		fprintf(stderr, "out of memory\n");		\
+		exit(1);					\
+	}							\
+	__str; })
+
+#endif				/* genksyms.h */
diff --git a/scripts/genksyms/keywords.c b/scripts/genksyms/keywords.c
new file mode 100644
index 000000000..ee1499d27
--- /dev/null
+++ b/scripts/genksyms/keywords.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+static struct resword {
+	const char *name;
+	int token;
+} keywords[] = {
+	{ "__GENKSYMS_EXPORT_SYMBOL", EXPORT_SYMBOL_KEYW },
+	{ "__asm", ASM_KEYW },
+	{ "__asm__", ASM_KEYW },
+	{ "__attribute", ATTRIBUTE_KEYW },
+	{ "__attribute__", ATTRIBUTE_KEYW },
+	{ "__const", CONST_KEYW },
+	{ "__const__", CONST_KEYW },
+	{ "__extension__", EXTENSION_KEYW },
+	{ "__inline", INLINE_KEYW },
+	{ "__inline__", INLINE_KEYW },
+	{ "__signed", SIGNED_KEYW },
+	{ "__signed__", SIGNED_KEYW },
+	{ "__typeof", TYPEOF_KEYW },
+	{ "__typeof__", TYPEOF_KEYW },
+	{ "__typeof_unqual", TYPEOF_KEYW },
+	{ "__typeof_unqual__", TYPEOF_KEYW },
+	{ "__volatile", VOLATILE_KEYW },
+	{ "__volatile__", VOLATILE_KEYW },
+	{ "__builtin_va_list", VA_LIST_KEYW },
+
+	{ "__int128", BUILTIN_INT_KEYW },
+	{ "__int128_t", BUILTIN_INT_KEYW },
+	{ "__uint128_t", BUILTIN_INT_KEYW },
+
+	// According to rth, c99 defines "_Bool", "__restrict", "__restrict__", "restrict".  KAO
+	{ "_Bool", BOOL_KEYW },
+	{ "__restrict", RESTRICT_KEYW },
+	{ "__restrict__", RESTRICT_KEYW },
+	{ "restrict", RESTRICT_KEYW },
+	{ "asm", ASM_KEYW },
+
+	// c11 keywords that can be used at module scope
+	{ "_Static_assert", STATIC_ASSERT_KEYW },
+
+	// attribute commented out in modutils 2.4.2.  People are using 'attribute' as a
+	// field name which breaks the genksyms parser.  It is not a gcc keyword anyway.
+	// KAO. },
+	// { "attribute", ATTRIBUTE_KEYW },
+
+	// X86 named address space qualifiers
+	{ "__seg_gs", X86_SEG_KEYW },
+	{ "__seg_fs", X86_SEG_KEYW },
+
+	{ "auto", AUTO_KEYW },
+	{ "char", CHAR_KEYW },
+	{ "const", CONST_KEYW },
+	{ "double", DOUBLE_KEYW },
+	{ "enum", ENUM_KEYW },
+	{ "extern", EXTERN_KEYW },
+	{ "float", FLOAT_KEYW },
+	{ "inline", INLINE_KEYW },
+	{ "int", INT_KEYW },
+	{ "long", LONG_KEYW },
+	{ "register", REGISTER_KEYW },
+	{ "short", SHORT_KEYW },
+	{ "signed", SIGNED_KEYW },
+	{ "static", STATIC_KEYW },
+	{ "struct", STRUCT_KEYW },
+	{ "typedef", TYPEDEF_KEYW },
+	{ "typeof", TYPEOF_KEYW },
+	{ "typeof_unqual", TYPEOF_KEYW },
+	{ "union", UNION_KEYW },
+	{ "unsigned", UNSIGNED_KEYW },
+	{ "void", VOID_KEYW },
+	{ "volatile", VOLATILE_KEYW },
+};
+
+#define NR_KEYWORDS (sizeof(keywords)/sizeof(struct resword))
+
+static int is_reserved_word(register const char *str, register unsigned int len)
+{
+	int i;
+	for (i = 0; i < NR_KEYWORDS; i++) {
+		struct resword *r = keywords + i;
+		int l = strlen(r->name);
+		if (len == l && !memcmp(str, r->name, len))
+			return r->token;
+	}
+	return -1;
+}
diff --git a/scripts/genksyms/lex.l b/scripts/genksyms/lex.l
new file mode 100644
index 000000000..f81033af1
--- /dev/null
+++ b/scripts/genksyms/lex.l
@@ -0,0 +1,449 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Lexical analysis for genksyms.
+ * Copyright 1996, 1997 Linux International.
+ *
+ * New implementation contributed by Richard Henderson <rth@tamu.edu>
+ * Based on original work by Bjorn Ekwall <bj0rn@blox.se>
+ *
+ * Taken from Linux modutils 2.4.22.
+ */
+
+%{
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "genksyms.h"
+#include "parse.tab.h"
+
+/* We've got a two-level lexer here.  We let flex do basic tokenization
+   and then we categorize those basic tokens in the second stage.  */
+#define YY_DECL		static int yylex1(void)
+
+%}
+
+IDENT			[A-Za-z_\$][A-Za-z0-9_\$]*
+
+O_INT			0[0-7]*
+D_INT			[1-9][0-9]*
+X_INT			0[Xx][0-9A-Fa-f]+
+I_SUF			[Uu]|[Ll]|[Uu][Ll]|[Ll][Uu]
+INT			({O_INT}|{D_INT}|{X_INT}){I_SUF}?
+
+FRAC			([0-9]*\.[0-9]+)|([0-9]+\.)
+EXP			[Ee][+-]?[0-9]+
+F_SUF			[FfLl]
+REAL			({FRAC}{EXP}?{F_SUF}?)|([0-9]+{EXP}{F_SUF}?)
+
+STRING			L?\"([^\\\"]*\\.)*[^\\\"]*\"
+CHAR			L?\'([^\\\']*\\.)*[^\\\']*\'
+
+MC_TOKEN		([~%^&*+=|<>/-]=)|(&&)|("||")|(->)|(<<)|(>>)
+
+/* We don't do multiple input files.  */
+%option noyywrap
+
+%option noinput
+
+%%
+
+u?int(8|16|32|64)x(1|2|4|8|16)_t	return BUILTIN_INT_KEYW;
+
+ /* Keep track of our location in the original source files.  */
+^#[ \t]+{INT}[ \t]+\"[^\"\n]+\".*\n	return FILENAME;
+^#.*\n					cur_line++;
+\n					cur_line++;
+
+ /* Ignore all other whitespace.  */
+[ \t\f\v\r]+				;
+
+
+{STRING}				return STRING;
+{CHAR}					return CHAR;
+{IDENT}					return IDENT;
+
+ /* The Pedant requires that the other C multi-character tokens be
+    recognized as tokens.  We don't actually use them since we don't
+    parse expressions, but we do want whitespace to be arranged
+    around them properly.  */
+{MC_TOKEN}				return OTHER;
+{INT}					return INT;
+{REAL}					return REAL;
+
+"..."					return DOTS;
+
+ /* All other tokens are single characters.  */
+.					return yytext[0];
+
+
+%%
+
+/* Bring in the keyword recognizer.  */
+
+#include "keywords.c"
+
+
+/* Macros to append to our phrase collection list.  */
+
+/*
+ * We mark any token, that that equals to a known enumerator, as
+ * SYM_ENUM_CONST. The parser will change this for struct and union tags later,
+ * the only problem is struct and union members:
+ *    enum e { a, b }; struct s { int a, b; }
+ * but in this case, the only effect will be, that the ABI checksums become
+ * more volatile, which is acceptable. Also, such collisions are quite rare,
+ * so far it was only observed in include/linux/telephony.h.
+ */
+#define _APP(T,L)	do {						   \
+			  cur_node = next_node;				   \
+			  next_node = xmalloc(sizeof(*next_node));	   \
+			  next_node->next = cur_node;			   \
+			  cur_node->string = memcpy(xmalloc(L+1), T, L+1); \
+			  cur_node->tag =				   \
+			    find_symbol(cur_node->string, SYM_ENUM_CONST, 1)?\
+			    SYM_ENUM_CONST : SYM_NORMAL ;		   \
+			  cur_node->in_source_file = in_source_file;       \
+			} while (0)
+
+#define APP		_APP(yytext, yyleng)
+
+
+/* The second stage lexer.  Here we incorporate knowledge of the state
+   of the parser to tailor the tokens that are returned.  */
+
+/*
+ * The lexer cannot distinguish whether a typedef'ed string is a TYPE or an
+ * IDENT. We need a hint from the parser to handle this accurately.
+ */
+bool dont_want_type_specifier;
+
+int
+yylex(void)
+{
+  static enum {
+    ST_NOTSTARTED, ST_NORMAL, ST_ATTRIBUTE, ST_ASM, ST_TYPEOF, ST_TYPEOF_1,
+    ST_BRACKET, ST_BRACE, ST_EXPRESSION, ST_STATIC_ASSERT,
+  } lexstate = ST_NOTSTARTED;
+
+  static int suppress_type_lookup, dont_want_brace_phrase;
+  static struct string_list *next_node;
+  static char *source_file;
+
+  int token, count = 0;
+  struct string_list *cur_node;
+
+  if (lexstate == ST_NOTSTARTED)
+    {
+      next_node = xmalloc(sizeof(*next_node));
+      next_node->next = NULL;
+      lexstate = ST_NORMAL;
+    }
+
+repeat:
+  token = yylex1();
+
+  if (token == 0)
+    return 0;
+  else if (token == FILENAME)
+    {
+      char *file, *e;
+
+      /* Save the filename and line number for later error messages.  */
+
+      if (cur_filename)
+	free(cur_filename);
+
+      file = strchr(yytext, '\"')+1;
+      e = strchr(file, '\"');
+      *e = '\0';
+      cur_filename = memcpy(xmalloc(e-file+1), file, e-file+1);
+      cur_line = atoi(yytext+2);
+
+      if (!source_file) {
+        source_file = xstrdup(cur_filename);
+        in_source_file = 1;
+      } else {
+        in_source_file = (strcmp(cur_filename, source_file) == 0);
+      }
+
+      goto repeat;
+    }
+
+  switch (lexstate)
+    {
+    case ST_NORMAL:
+      APP;
+      switch (token)
+	{
+	case IDENT:
+	  {
+	    int r = is_reserved_word(yytext, yyleng);
+	    if (r >= 0)
+	      {
+		switch (token = r)
+		  {
+		  case ATTRIBUTE_KEYW:
+		    lexstate = ST_ATTRIBUTE;
+		    count = 0;
+		    goto repeat;
+		  case ASM_KEYW:
+		    lexstate = ST_ASM;
+		    count = 0;
+		    goto repeat;
+		  case TYPEOF_KEYW:
+		    lexstate = ST_TYPEOF;
+		    count = 0;
+		    goto repeat;
+
+		  case STRUCT_KEYW:
+		  case UNION_KEYW:
+		  case ENUM_KEYW:
+		    dont_want_brace_phrase = 3;
+		    suppress_type_lookup = 2;
+		    goto fini;
+
+		  case EXPORT_SYMBOL_KEYW:
+		      goto fini;
+
+		  case STATIC_ASSERT_KEYW:
+		    lexstate = ST_STATIC_ASSERT;
+		    count = 0;
+		    goto repeat;
+		  }
+	      }
+	    if (!suppress_type_lookup && !dont_want_type_specifier)
+	      {
+		if (find_symbol(yytext, SYM_TYPEDEF, 1))
+		  token = TYPE;
+	      }
+	  }
+	  break;
+
+	case '[':
+	  lexstate = ST_BRACKET;
+	  count = 1;
+	  goto repeat;
+
+	case '{':
+	  if (dont_want_brace_phrase)
+	    break;
+	  lexstate = ST_BRACE;
+	  count = 1;
+	  goto repeat;
+
+	case '=': case ':':
+	  lexstate = ST_EXPRESSION;
+	  break;
+
+	default:
+	  break;
+	}
+      break;
+
+    case ST_ATTRIBUTE:
+      APP;
+      switch (token)
+	{
+	case '(':
+	  ++count;
+	  goto repeat;
+	case ')':
+	  if (--count == 0)
+	    {
+	      lexstate = ST_NORMAL;
+	      token = ATTRIBUTE_PHRASE;
+	      break;
+	    }
+	  goto repeat;
+	default:
+	  goto repeat;
+	}
+      break;
+
+    case ST_ASM:
+      APP;
+      switch (token)
+	{
+	case '(':
+	  ++count;
+	  goto repeat;
+	case ')':
+	  if (--count == 0)
+	    {
+	      lexstate = ST_NORMAL;
+	      token = ASM_PHRASE;
+	      break;
+	    }
+	  goto repeat;
+	default:
+	  goto repeat;
+	}
+      break;
+
+    case ST_TYPEOF_1:
+      if (token == IDENT)
+	{
+	  if (is_reserved_word(yytext, yyleng) >= 0
+	      || find_symbol(yytext, SYM_TYPEDEF, 1))
+	    {
+	      yyless(0);
+	      unput('(');
+	      lexstate = ST_NORMAL;
+	      token = TYPEOF_KEYW;
+	      break;
+	    }
+	  _APP("(", 1);
+	}
+	lexstate = ST_TYPEOF;
+	/* FALLTHRU */
+
+    case ST_TYPEOF:
+      switch (token)
+	{
+	case '(':
+	  if ( ++count == 1 )
+	    lexstate = ST_TYPEOF_1;
+	  else
+	    APP;
+	  goto repeat;
+	case ')':
+	  APP;
+	  if (--count == 0)
+	    {
+	      lexstate = ST_NORMAL;
+	      token = TYPEOF_PHRASE;
+	      break;
+	    }
+	  goto repeat;
+	default:
+	  APP;
+	  goto repeat;
+	}
+      break;
+
+    case ST_BRACKET:
+      APP;
+      switch (token)
+	{
+	case '[':
+	  ++count;
+	  goto repeat;
+	case ']':
+	  if (--count == 0)
+	    {
+	      lexstate = ST_NORMAL;
+	      token = BRACKET_PHRASE;
+	      break;
+	    }
+	  goto repeat;
+	default:
+	  goto repeat;
+	}
+      break;
+
+    case ST_BRACE:
+      APP;
+      switch (token)
+	{
+	case '{':
+	  ++count;
+	  goto repeat;
+	case '}':
+	  if (--count == 0)
+	    {
+	      lexstate = ST_NORMAL;
+	      token = BRACE_PHRASE;
+	      break;
+	    }
+	  goto repeat;
+	default:
+	  goto repeat;
+	}
+      break;
+
+    case ST_EXPRESSION:
+      switch (token)
+	{
+	case '(': case '[': case '{':
+	  ++count;
+	  APP;
+	  goto repeat;
+	case '}':
+	  /* is this the last line of an enum declaration? */
+	  if (count == 0)
+	    {
+	      /* Put back the token we just read so's we can find it again
+		 after registering the expression.  */
+	      unput(token);
+
+	      lexstate = ST_NORMAL;
+	      token = EXPRESSION_PHRASE;
+	      break;
+	    }
+	  /* FALLTHRU */
+	case ')': case ']':
+	  --count;
+	  APP;
+	  goto repeat;
+	case ',': case ';':
+	  if (count == 0)
+	    {
+	      /* Put back the token we just read so's we can find it again
+		 after registering the expression.  */
+	      unput(token);
+
+	      lexstate = ST_NORMAL;
+	      token = EXPRESSION_PHRASE;
+	      break;
+	    }
+	  APP;
+	  goto repeat;
+	default:
+	  APP;
+	  goto repeat;
+	}
+      break;
+
+    case ST_STATIC_ASSERT:
+      APP;
+      switch (token)
+	{
+	case '(':
+	  ++count;
+	  goto repeat;
+	case ')':
+	  if (--count == 0)
+	    {
+	      lexstate = ST_NORMAL;
+	      token = STATIC_ASSERT_PHRASE;
+	      break;
+	    }
+	  goto repeat;
+	default:
+	  goto repeat;
+	}
+      break;
+
+    default:
+      exit(1);
+    }
+fini:
+
+  if (suppress_type_lookup > 0)
+    --suppress_type_lookup;
+
+  /*
+   *  __attribute__() can be placed immediately after the 'struct' keyword.
+   *  e.g.) struct __attribute__((__packed__)) foo { ... };
+   */
+  if (token != ATTRIBUTE_PHRASE && dont_want_brace_phrase > 0)
+    --dont_want_brace_phrase;
+
+  yylval = &next_node->next;
+
+  return token;
+}
diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y
new file mode 100644
index 000000000..cabcd146f
--- /dev/null
+++ b/scripts/genksyms/parse.y
@@ -0,0 +1,539 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * C global declaration parser for genksyms.
+ * Copyright 1996, 1997 Linux International.
+ *
+ * New implementation contributed by Richard Henderson <rth@tamu.edu>
+ * Based on original work by Bjorn Ekwall <bj0rn@blox.se>
+ *
+ * This file is part of the Linux modutils.
+ */
+
+%{
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include "genksyms.h"
+
+static int is_typedef;
+static int is_extern;
+static char *current_name;
+static struct string_list *decl_spec;
+
+static void yyerror(const char *);
+
+static inline void
+remove_node(struct string_list **p)
+{
+  struct string_list *node = *p;
+  *p = node->next;
+  free_node(node);
+}
+
+static inline void
+remove_list(struct string_list **pb, struct string_list **pe)
+{
+  struct string_list *b = *pb, *e = *pe;
+  *pb = e;
+  free_list(b, e);
+}
+
+/* Record definition of a struct/union/enum */
+static void record_compound(struct string_list **keyw,
+		       struct string_list **ident,
+		       struct string_list **body,
+		       enum symbol_type type)
+{
+	struct string_list *b = *body, *i = *ident, *r;
+
+	if (i->in_source_file) {
+		remove_node(keyw);
+		(*ident)->tag = type;
+		remove_list(body, ident);
+		return;
+	}
+	r = copy_node(i); r->tag = type;
+	r->next = (*keyw)->next; *body = r; (*keyw)->next = NULL;
+	add_symbol(i->string, type, b, is_extern);
+}
+
+%}
+
+%token ASM_KEYW
+%token ATTRIBUTE_KEYW
+%token AUTO_KEYW
+%token BOOL_KEYW
+%token BUILTIN_INT_KEYW
+%token CHAR_KEYW
+%token CONST_KEYW
+%token DOUBLE_KEYW
+%token ENUM_KEYW
+%token EXTERN_KEYW
+%token EXTENSION_KEYW
+%token FLOAT_KEYW
+%token INLINE_KEYW
+%token INT_KEYW
+%token LONG_KEYW
+%token REGISTER_KEYW
+%token RESTRICT_KEYW
+%token SHORT_KEYW
+%token SIGNED_KEYW
+%token STATIC_KEYW
+%token STATIC_ASSERT_KEYW
+%token STRUCT_KEYW
+%token TYPEDEF_KEYW
+%token UNION_KEYW
+%token UNSIGNED_KEYW
+%token VOID_KEYW
+%token VOLATILE_KEYW
+%token TYPEOF_KEYW
+%token VA_LIST_KEYW
+
+%token X86_SEG_KEYW
+
+%token EXPORT_SYMBOL_KEYW
+
+%token ASM_PHRASE
+%token ATTRIBUTE_PHRASE
+%token TYPEOF_PHRASE
+%token BRACE_PHRASE
+%token BRACKET_PHRASE
+%token EXPRESSION_PHRASE
+%token STATIC_ASSERT_PHRASE
+
+%token CHAR
+%token DOTS
+%token IDENT
+%token INT
+%token REAL
+%token STRING
+%token TYPE
+%token OTHER
+%token FILENAME
+
+%%
+
+declaration_seq:
+	declaration
+	| declaration_seq declaration
+	;
+
+declaration:
+	{ is_typedef = 0; is_extern = 0; current_name = NULL; decl_spec = NULL; }
+	declaration1
+	{ free_list(*$2, NULL); *$2 = NULL; }
+	;
+
+declaration1:
+	EXTENSION_KEYW TYPEDEF_KEYW { is_typedef = 1; } simple_declaration
+		{ $$ = $4; }
+	| TYPEDEF_KEYW { is_typedef = 1; } simple_declaration
+		{ $$ = $3; }
+	| simple_declaration
+	| function_definition
+	| asm_definition
+	| export_definition
+	| static_assert
+	| error ';'				{ $$ = $2; }
+	| error '}'				{ $$ = $2; }
+	;
+
+simple_declaration:
+	decl_specifier_seq_opt init_declarator_list_opt ';'
+		{ if (current_name) {
+		    struct string_list *decl = (*$3)->next;
+		    (*$3)->next = NULL;
+		    add_symbol(current_name,
+			       is_typedef ? SYM_TYPEDEF : SYM_NORMAL,
+			       decl, is_extern);
+		    current_name = NULL;
+		  }
+		  $$ = $3;
+		  dont_want_type_specifier = false;
+		}
+	;
+
+init_declarator_list_opt:
+	/* empty */			{ $$ = NULL; }
+	| init_declarator_list		{ free_list(decl_spec, NULL); $$ = $1; }
+	;
+
+init_declarator_list:
+	init_declarator
+		{ struct string_list *decl = *$1;
+		  *$1 = NULL;
+
+		  /* avoid sharing among multiple init_declarators */
+		  if (decl_spec)
+		    decl_spec = copy_list_range(decl_spec, NULL);
+
+		  add_symbol(current_name,
+			     is_typedef ? SYM_TYPEDEF : SYM_NORMAL, decl, is_extern);
+		  current_name = NULL;
+		  $$ = $1;
+		  dont_want_type_specifier = true;
+		}
+	| init_declarator_list ',' attribute_opt init_declarator
+		{ struct string_list *decl = *$4;
+		  *$4 = NULL;
+		  free_list(*$2, NULL);
+		  *$2 = decl_spec;
+
+		  /* avoid sharing among multiple init_declarators */
+		  if (decl_spec)
+		    decl_spec = copy_list_range(decl_spec, NULL);
+
+		  add_symbol(current_name,
+			     is_typedef ? SYM_TYPEDEF : SYM_NORMAL, decl, is_extern);
+		  current_name = NULL;
+		  $$ = $4;
+		  dont_want_type_specifier = true;
+		}
+	;
+
+init_declarator:
+	declarator asm_phrase_opt attribute_opt initializer_opt
+		{ $$ = $4 ? $4 : $3 ? $3 : $2 ? $2 : $1; }
+	;
+
+/* Hang on to the specifiers so that we can reuse them.  */
+decl_specifier_seq_opt:
+	/* empty */				{ decl_spec = NULL; }
+	| decl_specifier_seq
+	;
+
+decl_specifier_seq:
+	attribute_opt decl_specifier		{ decl_spec = *$2; }
+	| decl_specifier_seq decl_specifier	{ decl_spec = *$2; }
+	| decl_specifier_seq ATTRIBUTE_PHRASE	{ decl_spec = *$2; }
+	;
+
+decl_specifier:
+	storage_class_specifier
+		{ /* Version 2 checksumming ignores storage class, as that
+		     is really irrelevant to the linkage.  */
+		  remove_node($1);
+		  $$ = $1;
+		}
+	| type_specifier	{ dont_want_type_specifier = true; $$ = $1; }
+	| type_qualifier
+	;
+
+storage_class_specifier:
+	AUTO_KEYW
+	| REGISTER_KEYW
+	| STATIC_KEYW
+	| EXTERN_KEYW	{ is_extern = 1; $$ = $1; }
+	| INLINE_KEYW	{ is_extern = 0; $$ = $1; }
+	;
+
+type_specifier:
+	simple_type_specifier
+	| TYPEOF_KEYW '(' parameter_declaration ')'
+	| TYPEOF_PHRASE
+
+	/* References to s/u/e's defined elsewhere.  Rearrange things
+	   so that it is easier to expand the definition fully later.  */
+	| STRUCT_KEYW attribute_opt IDENT
+		{ remove_node($1); (*$3)->tag = SYM_STRUCT; $$ = $3; }
+	| UNION_KEYW attribute_opt IDENT
+		{ remove_node($1); (*$3)->tag = SYM_UNION; $$ = $3; }
+	| ENUM_KEYW IDENT
+		{ remove_node($1); (*$2)->tag = SYM_ENUM; $$ = $2; }
+
+	/* Full definitions of an s/u/e.  Record it.  */
+	| STRUCT_KEYW attribute_opt IDENT class_body
+		{ record_compound($1, $3, $4, SYM_STRUCT); $$ = $4; }
+	| UNION_KEYW attribute_opt IDENT class_body
+		{ record_compound($1, $3, $4, SYM_UNION); $$ = $4; }
+	| ENUM_KEYW IDENT enum_body
+		{ record_compound($1, $2, $3, SYM_ENUM); $$ = $3; }
+	/*
+	 * Anonymous enum definition. Tell add_symbol() to restart its counter.
+	 */
+	| ENUM_KEYW enum_body
+		{ add_symbol(NULL, SYM_ENUM, NULL, 0); $$ = $2; }
+	/* Anonymous s/u definitions.  Nothing needs doing.  */
+	| STRUCT_KEYW attribute_opt class_body		{ $$ = $3; }
+	| UNION_KEYW attribute_opt class_body		{ $$ = $3; }
+	;
+
+simple_type_specifier:
+	CHAR_KEYW
+	| SHORT_KEYW
+	| INT_KEYW
+	| LONG_KEYW
+	| SIGNED_KEYW
+	| UNSIGNED_KEYW
+	| FLOAT_KEYW
+	| DOUBLE_KEYW
+	| VOID_KEYW
+	| BOOL_KEYW
+	| VA_LIST_KEYW
+	| BUILTIN_INT_KEYW
+	| TYPE			{ (*$1)->tag = SYM_TYPEDEF; $$ = $1; }
+	;
+
+ptr_operator:
+	'*' type_qualifier_seq_opt
+		{ $$ = $2 ? $2 : $1; }
+	;
+
+type_qualifier_seq_opt:
+	/* empty */					{ $$ = NULL; }
+	| type_qualifier_seq
+	;
+
+type_qualifier_seq:
+	type_qualifier
+	| ATTRIBUTE_PHRASE
+	| type_qualifier_seq type_qualifier		{ $$ = $2; }
+	| type_qualifier_seq ATTRIBUTE_PHRASE		{ $$ = $2; }
+	;
+
+type_qualifier:
+	X86_SEG_KEYW
+	| CONST_KEYW | VOLATILE_KEYW
+	| RESTRICT_KEYW
+		{ /* restrict has no effect in prototypes so ignore it */
+		  remove_node($1);
+		  $$ = $1;
+		}
+	;
+
+declarator:
+	ptr_operator declarator			{ $$ = $2; }
+	| direct_declarator
+	;
+
+direct_declarator:
+	IDENT
+		{ if (current_name != NULL) {
+		    error_with_pos("unexpected second declaration name");
+		    YYERROR;
+		  } else {
+		    current_name = (*$1)->string;
+		    $$ = $1;
+		  }
+		  dont_want_type_specifier = false;
+		}
+	| direct_declarator '(' parameter_declaration_clause ')'
+		{ $$ = $4; }
+	| direct_declarator '(' error ')'
+		{ $$ = $4; }
+	| direct_declarator BRACKET_PHRASE
+		{ $$ = $2; }
+	| '(' attribute_opt declarator ')'
+		{ $$ = $4; }
+	;
+
+/* Nested declarators differ from regular declarators in that they do
+   not record the symbols they find in the global symbol table.  */
+nested_declarator:
+	ptr_operator nested_declarator		{ $$ = $2; }
+	| direct_nested_declarator
+	;
+
+direct_nested_declarator:
+	direct_nested_declarator1
+	| direct_nested_declarator1 '(' parameter_declaration_clause ')'
+		{ $$ = $4; }
+	;
+
+direct_nested_declarator1:
+	IDENT	{ $$ = $1; dont_want_type_specifier = false; }
+	| direct_nested_declarator1 '(' error ')'
+		{ $$ = $4; }
+	| direct_nested_declarator1 BRACKET_PHRASE
+		{ $$ = $2; }
+	| '(' attribute_opt nested_declarator ')'
+		{ $$ = $4; }
+	| '(' error ')'
+		{ $$ = $3; }
+	;
+
+parameter_declaration_clause:
+	parameter_declaration_list_opt DOTS		{ $$ = $2; }
+	| parameter_declaration_list_opt
+	| parameter_declaration_list ',' DOTS		{ $$ = $3; }
+	;
+
+parameter_declaration_list_opt:
+	/* empty */					{ $$ = NULL; }
+	| parameter_declaration_list
+	;
+
+parameter_declaration_list:
+	parameter_declaration
+		{ $$ = $1; dont_want_type_specifier = false; }
+	| parameter_declaration_list ',' parameter_declaration
+		{ $$ = $3; dont_want_type_specifier = false; }
+	;
+
+parameter_declaration:
+	decl_specifier_seq abstract_declarator_opt
+		{ $$ = $2 ? $2 : $1; }
+	;
+
+abstract_declarator_opt:
+	/* empty */				{ $$ = NULL; }
+	| abstract_declarator
+	;
+
+abstract_declarator:
+	ptr_operator
+	| ptr_operator abstract_declarator
+		{ $$ = $2 ? $2 : $1; }
+	| direct_abstract_declarator attribute_opt
+		{ $$ = $2; dont_want_type_specifier = false; }
+	;
+
+direct_abstract_declarator:
+	direct_abstract_declarator1
+	| direct_abstract_declarator1 open_paren parameter_declaration_clause ')'
+		{ $$ = $4; }
+	| open_paren parameter_declaration_clause ')'
+		{ $$ = $3; }
+	;
+
+direct_abstract_declarator1:
+	  IDENT
+		{ /* For version 2 checksums, we don't want to remember
+		     private parameter names.  */
+		  remove_node($1);
+		  $$ = $1;
+		}
+	| direct_abstract_declarator1 open_paren error ')'
+		{ $$ = $4; }
+	| direct_abstract_declarator1 BRACKET_PHRASE
+		{ $$ = $2; }
+	| open_paren attribute_opt abstract_declarator ')'
+		{ $$ = $4; }
+	| open_paren error ')'
+		{ $$ = $3; }
+	| BRACKET_PHRASE
+	;
+
+open_paren:
+	'('	{ $$ = $1; dont_want_type_specifier = false; }
+	;
+
+function_definition:
+	decl_specifier_seq_opt declarator BRACE_PHRASE
+		{ struct string_list *decl = *$2;
+		  *$2 = NULL;
+		  add_symbol(current_name, SYM_NORMAL, decl, is_extern);
+		  $$ = $3;
+		}
+	;
+
+initializer_opt:
+	/* empty */					{ $$ = NULL; }
+	| initializer
+	;
+
+/* We never care about the contents of an initializer.  */
+initializer:
+	'=' EXPRESSION_PHRASE
+		{ remove_list($2, &(*$1)->next); $$ = $2; }
+	;
+
+class_body:
+	'{' member_specification_opt '}'		{ $$ = $3; }
+	| '{' error '}'					{ $$ = $3; }
+	;
+
+member_specification_opt:
+	/* empty */					{ $$ = NULL; }
+	| member_specification
+	;
+
+member_specification:
+	member_declaration
+	| member_specification member_declaration	{ $$ = $2; }
+	;
+
+member_declaration:
+	decl_specifier_seq_opt member_declarator_list_opt ';'
+		{ $$ = $3; dont_want_type_specifier = false; }
+	| error ';'
+		{ $$ = $2; dont_want_type_specifier = false; }
+	;
+
+member_declarator_list_opt:
+	/* empty */					{ $$ = NULL; }
+	| member_declarator_list
+	;
+
+member_declarator_list:
+	member_declarator
+		{ $$ = $1; dont_want_type_specifier = true; }
+	| member_declarator_list ',' member_declarator
+		{ $$ = $3; dont_want_type_specifier = true; }
+	;
+
+member_declarator:
+	nested_declarator attribute_opt			{ $$ = $2 ? $2 : $1; }
+	| IDENT member_bitfield_declarator		{ $$ = $2; }
+	| member_bitfield_declarator
+	;
+
+member_bitfield_declarator:
+	':' EXPRESSION_PHRASE				{ $$ = $2; }
+	;
+
+attribute_opt:
+	/* empty */					{ $$ = NULL; }
+	| attribute_opt ATTRIBUTE_PHRASE		{ $$ = $2; }
+	;
+
+enum_body:
+	'{' enumerator_list '}'				{ $$ = $3; }
+	| '{' enumerator_list ',' '}'			{ $$ = $4; }
+	 ;
+
+enumerator_list:
+	enumerator
+	| enumerator_list ',' enumerator
+
+enumerator:
+	IDENT
+		{
+			const char *name = (*$1)->string;
+			add_symbol(name, SYM_ENUM_CONST, NULL, 0);
+		}
+	| IDENT '=' EXPRESSION_PHRASE
+		{
+			const char *name = (*$1)->string;
+			struct string_list *expr = copy_list_range(*$3, *$2);
+			add_symbol(name, SYM_ENUM_CONST, expr, 0);
+		}
+
+asm_definition:
+	ASM_PHRASE ';'					{ $$ = $2; }
+	;
+
+asm_phrase_opt:
+	/* empty */					{ $$ = NULL; }
+	| ASM_PHRASE
+	;
+
+export_definition:
+	EXPORT_SYMBOL_KEYW '(' IDENT ')' ';'
+		{ export_symbol((*$3)->string); $$ = $5; }
+	;
+
+/* Ignore any module scoped _Static_assert(...) */
+static_assert:
+	STATIC_ASSERT_PHRASE ';'			{ $$ = $2; }
+	;
+
+%%
+
+static void
+yyerror(const char *e)
+{
+  error_with_pos("%s", e);
+}