From 6b91ff002c67b2502009f99115c4b7fe5b7b8248 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 2 May 2025 16:12:05 +0200
Subject: modpost: Use for() loop

Slight cleanup by using a for() loop instead of while(). This makes it
clearer what is the iteration and what is the actual work done.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/mod/modpost.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

(limited to 'scripts')

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index be89921d60b6..2d1c059bf6cf 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1595,12 +1595,10 @@ static void read_symbols(const char *modname)
 			license = get_next_modinfo(&info, "license", license);
 		}
 
-		namespace = get_modinfo(&info, "import_ns");
-		while (namespace) {
+		for (namespace = get_modinfo(&info, "import_ns");
+		     namespace;
+		     namespace = get_next_modinfo(&info, "import_ns", namespace))
 			add_namespace(&mod->imported_namespaces, namespace);
-			namespace = get_next_modinfo(&info, "import_ns",
-						     namespace);
-		}
 
 		if (!get_modinfo(&info, "description"))
 			warn("missing MODULE_DESCRIPTION() in %s\n", modname);
-- 
cgit v1.2.3


From 520b1a147d918eb07132c847ad5598a17d3ff7ca Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 2 May 2025 16:12:06 +0200
Subject: module: Add module specific symbol namespace support

Designate the "module:${modname}" symbol namespace to mean: 'only
export to the named module'.

Notably, explicit imports of anything in the "module:" space is
forbidden.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 kernel/module/main.c  | 33 +++++++++++++++++++++++++++++++--
 scripts/mod/modpost.c | 11 ++++++++++-
 2 files changed, 41 insertions(+), 3 deletions(-)

(limited to 'scripts')

diff --git a/kernel/module/main.c b/kernel/module/main.c
index a2859dc3eea6..5c5e725597e1 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1083,6 +1083,14 @@ static char *get_modinfo(const struct load_info *info, const char *tag)
 	return get_next_modinfo(info, tag, NULL);
 }
 
+static bool verify_module_namespace(const char *namespace, const char *modname)
+{
+	const char *prefix = "module:";
+
+	return strstarts(namespace, prefix) &&
+	       !strcmp(namespace + strlen(prefix), modname);
+}
+
 static int verify_namespace_is_imported(const struct load_info *info,
 					const struct kernel_symbol *sym,
 					struct module *mod)
@@ -1092,6 +1100,10 @@ static int verify_namespace_is_imported(const struct load_info *info,
 
 	namespace = kernel_symbol_namespace(sym);
 	if (namespace && namespace[0]) {
+
+		if (verify_module_namespace(namespace, mod->name))
+			return 0;
+
 		for_each_modinfo_entry(imported_namespace, info, "import_ns") {
 			if (strcmp(namespace, imported_namespace) == 0)
 				return 0;
@@ -1659,15 +1671,30 @@ static void module_license_taint_check(struct module *mod, const char *license)
 	}
 }
 
-static void setup_modinfo(struct module *mod, struct load_info *info)
+static int setup_modinfo(struct module *mod, struct load_info *info)
 {
 	const struct module_attribute *attr;
+	char *imported_namespace;
 	int i;
 
 	for (i = 0; (attr = modinfo_attrs[i]); i++) {
 		if (attr->setup)
 			attr->setup(mod, get_modinfo(info, attr->attr.name));
 	}
+
+	for_each_modinfo_entry(imported_namespace, info, "import_ns") {
+		/*
+		 * 'module:' prefixed namespaces are implicit, disallow
+		 * explicit imports.
+		 */
+		if (strstarts(imported_namespace, "module:")) {
+			pr_err("%s: module tries to import module namespace: %s\n",
+			       mod->name, imported_namespace);
+			return -EPERM;
+		}
+	}
+
+	return 0;
 }
 
 static void free_modinfo(struct module *mod)
@@ -3335,7 +3362,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
 		goto free_unload;
 
 	/* Set up MODINFO_ATTR fields */
-	setup_modinfo(mod, info);
+	err = setup_modinfo(mod, info);
+	if (err)
+		goto free_modinfo;
 
 	/* Fix up syms, so that st_value is a pointer to location. */
 	err = simplify_symbols(mod, info);
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 2d1c059bf6cf..c9ff4db26edb 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1682,6 +1682,14 @@ void buf_write(struct buffer *buf, const char *s, int len)
 	buf->pos += len;
 }
 
+static bool verify_module_namespace(const char *namespace, const char *modname)
+{
+	const char *prefix = "module:";
+
+	return strstarts(namespace, prefix) &&
+	       !strcmp(namespace + strlen(prefix), modname);
+}
+
 static void check_exports(struct module *mod)
 {
 	struct symbol *s, *exp;
@@ -1709,7 +1717,8 @@ static void check_exports(struct module *mod)
 
 		basename = get_basename(mod->name);
 
-		if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
+		if (!verify_module_namespace(exp->namespace, basename) &&
+		    !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
 			modpost_log(!allow_missing_ns_imports,
 				    "module %s uses symbol %s from namespace %s, but does not import it.\n",
 				    basename, exp->name, exp->namespace);
-- 
cgit v1.2.3


From 754f8733fc09dd92093cfbd34fa71a42d152b250 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 2 May 2025 16:12:07 +0200
Subject: module: Extend the module namespace parsing

Instead of only accepting "module:${name}", extend it with a comma
separated list of module names and add tail glob support.

That is, something like: "module:foo-*,bar" is now possible.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 kernel/module/main.c  | 36 ++++++++++++++++++++++++++++++++++--
 scripts/mod/modpost.c | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 68 insertions(+), 4 deletions(-)

(limited to 'scripts')

diff --git a/kernel/module/main.c b/kernel/module/main.c
index 5c5e725597e1..e4b6968dc308 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1083,12 +1083,44 @@ static char *get_modinfo(const struct load_info *info, const char *tag)
 	return get_next_modinfo(info, tag, NULL);
 }
 
+/**
+ * verify_module_namespace() - does @modname have access to this symbol's @namespace
+ * @namespace: export symbol namespace
+ * @modname: module name
+ *
+ * If @namespace is prefixed with "module:" to indicate it is a module namespace
+ * then test if @modname matches any of the comma separated patterns.
+ *
+ * The patterns only support tail-glob.
+ */
 static bool verify_module_namespace(const char *namespace, const char *modname)
 {
+	size_t len, modlen = strlen(modname);
 	const char *prefix = "module:";
+	const char *sep;
+	bool glob;
+
+	if (!strstarts(namespace, prefix))
+		return false;
+
+	for (namespace += strlen(prefix); *namespace; namespace = sep) {
+		sep = strchrnul(namespace, ',');
+		len = sep - namespace;
 
-	return strstarts(namespace, prefix) &&
-	       !strcmp(namespace + strlen(prefix), modname);
+		glob = false;
+		if (sep[-1] == '*') {
+			len--;
+			glob = true;
+		}
+
+		if (*sep)
+			sep++;
+
+		if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+			return true;
+	}
+
+	return false;
 }
 
 static int verify_namespace_is_imported(const struct load_info *info,
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index c9ff4db26edb..16a69a129805 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1682,12 +1682,44 @@ void buf_write(struct buffer *buf, const char *s, int len)
 	buf->pos += len;
 }
 
+/**
+ * verify_module_namespace() - does @modname have access to this symbol's @namespace
+ * @namespace: export symbol namespace
+ * @modname: module name
+ *
+ * If @namespace is prefixed with "module:" to indicate it is a module namespace
+ * then test if @modname matches any of the comma separated patterns.
+ *
+ * The patterns only support tail-glob.
+ */
 static bool verify_module_namespace(const char *namespace, const char *modname)
 {
+	size_t len, modlen = strlen(modname);
 	const char *prefix = "module:";
+	const char *sep;
+	bool glob;
+
+	if (!strstarts(namespace, prefix))
+		return false;
+
+	for (namespace += strlen(prefix); *namespace; namespace = sep) {
+		sep = strchrnul(namespace, ',');
+		len = sep - namespace;
 
-	return strstarts(namespace, prefix) &&
-	       !strcmp(namespace + strlen(prefix), modname);
+		glob = false;
+		if (sep[-1] == '*') {
+			len--;
+			glob = true;
+		}
+
+		if (*sep)
+			sep++;
+
+		if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+			return true;
+	}
+
+	return false;
 }
 
 static void check_exports(struct module *mod)
-- 
cgit v1.2.3


From ff2c5f5a9e01b9fc3b4959c2b3f40843cc0a5ecb Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Wed, 7 May 2025 23:14:05 +0000
Subject: gendwarfksyms: Clean up kABI rule look-ups

Reduce code duplication by moving kABI rule look-ups to separate
functions.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/gendwarfksyms/kabi.c | 101 +++++++++++++++++++------------------------
 1 file changed, 44 insertions(+), 57 deletions(-)

(limited to 'scripts')

diff --git a/scripts/gendwarfksyms/kabi.c b/scripts/gendwarfksyms/kabi.c
index 66f01fcd1607..badf8d46b154 100644
--- a/scripts/gendwarfksyms/kabi.c
+++ b/scripts/gendwarfksyms/kabi.c
@@ -222,33 +222,55 @@ void kabi_read_rules(int fd)
 	check(elf_end(elf));
 }
 
-bool kabi_is_declonly(const char *fqn)
+static char *get_enumerator_target(const char *fqn, const char *field)
+{
+	char *target = NULL;
+
+	if (asprintf(&target, "%s %s", fqn, field) < 0)
+		error("asprintf failed for '%s %s'", fqn, field);
+
+	return target;
+}
+
+static struct rule *find_rule(enum kabi_rule_type type, const char *target)
 {
 	struct rule *rule;
 
 	if (!stable)
-		return false;
-	if (!fqn || !*fqn)
-		return false;
+		return NULL;
+	if (!target || !*target)
+		return NULL;
 
 	hash_for_each_possible(rules, rule, hash,
-			       rule_values_hash(KABI_RULE_TYPE_DECLONLY, fqn)) {
-		if (rule->type == KABI_RULE_TYPE_DECLONLY &&
-		    !strcmp(fqn, rule->target))
-			return true;
+			       rule_values_hash(type, target)) {
+		if (rule->type == type && !strcmp(target, rule->target))
+			return rule;
 	}
 
-	return false;
+	return NULL;
 }
 
-static char *get_enumerator_target(const char *fqn, const char *field)
+static struct rule *find_enumerator_rule(enum kabi_rule_type type,
+					 const char *fqn, const char *field)
 {
-	char *target = NULL;
+	struct rule *rule;
+	char *target;
 
-	if (asprintf(&target, "%s %s", fqn, field) < 0)
-		error("asprintf failed for '%s %s'", fqn, field);
+	if (!stable)
+		return NULL;
+	if (!fqn || !*fqn || !field || !*field)
+		return NULL;
 
-	return target;
+	target = get_enumerator_target(fqn, field);
+	rule = find_rule(type, target);
+
+	free(target);
+	return rule;
+}
+
+bool kabi_is_declonly(const char *fqn)
+{
+	return !!find_rule(KABI_RULE_TYPE_DECLONLY, fqn);
 }
 
 static unsigned long get_ulong_value(const char *value)
@@ -267,58 +289,23 @@ static unsigned long get_ulong_value(const char *value)
 
 bool kabi_is_enumerator_ignored(const char *fqn, const char *field)
 {
-	bool match = false;
-	struct rule *rule;
-	char *target;
-
-	if (!stable)
-		return false;
-	if (!fqn || !*fqn || !field || !*field)
-		return false;
-
-	target = get_enumerator_target(fqn, field);
-
-	hash_for_each_possible(
-		rules, rule, hash,
-		rule_values_hash(KABI_RULE_TYPE_ENUMERATOR_IGNORE, target)) {
-		if (rule->type == KABI_RULE_TYPE_ENUMERATOR_IGNORE &&
-		    !strcmp(target, rule->target)) {
-			match = true;
-			break;
-		}
-	}
-
-	free(target);
-	return match;
+	return !!find_enumerator_rule(KABI_RULE_TYPE_ENUMERATOR_IGNORE, fqn,
+				      field);
 }
 
 bool kabi_get_enumerator_value(const char *fqn, const char *field,
 			       unsigned long *value)
 {
-	bool match = false;
 	struct rule *rule;
-	char *target;
 
-	if (!stable)
-		return false;
-	if (!fqn || !*fqn || !field || !*field)
-		return false;
-
-	target = get_enumerator_target(fqn, field);
-
-	hash_for_each_possible(rules, rule, hash,
-			       rule_values_hash(KABI_RULE_TYPE_ENUMERATOR_VALUE,
-						target)) {
-		if (rule->type == KABI_RULE_TYPE_ENUMERATOR_VALUE &&
-		    !strcmp(target, rule->target)) {
-			*value = get_ulong_value(rule->value);
-			match = true;
-			break;
-		}
+	rule = find_enumerator_rule(KABI_RULE_TYPE_ENUMERATOR_VALUE, fqn,
+				    field);
+	if (rule) {
+		*value = get_ulong_value(rule->value);
+		return true;
 	}
 
-	free(target);
-	return match;
+	return false;
 }
 
 void kabi_free(void)
-- 
cgit v1.2.3


From db59d74e5da144111fc133fb1bf72e6392bdb04e Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Wed, 7 May 2025 23:14:06 +0000
Subject: gendwarfksyms: Add a kABI rule to override byte_size attributes

A data structure can be partially opaque to modules if its
allocation is handled by the core kernel, and modules only need
to access some of its members. In this situation, it's possible
to append new members to the structure without breaking the ABI,
as long as the layout for the original members remains unchanged.
For example, consider the following struct:

  struct s {
          unsigned long a;
          void *p;
  };

gendwarfksyms --stable --dump-dies produces the following type
expansion:

  variable structure_type s {
    member base_type long unsigned int byte_size(8) encoding(7) a
      data_member_location(0) ,
    member pointer_type {
      base_type void
    } byte_size(8) p data_member_location(8)
  } byte_size(16)

To append new members, we can use the KABI_IGNORE() macro to
hide them from gendwarfksyms --stable:

  struct s {
          /* old members with unchanged layout */
          unsigned long a;
          void *p;

          /* new members not accessed by modules */
          KABI_IGNORE(0, unsigned long n);
  };

However, we can't hide the fact that adding new members changes
the struct size, as seen in the updated type string:

  variable structure_type s {
    member base_type long unsigned int byte_size(8) encoding(7) a
      data_member_location(0) ,
    member pointer_type {
      base_type void
    } byte_size(8) p data_member_location(8)
  } byte_size(24)

In order to support this use case, add a kABI rule that makes it
possible to override the byte_size attribute for types:

  /*
   * struct s allocation is handled by the kernel, so
   * appending new members without changing the original
   * layout won't break the ABI.
   */
  KABI_BYTE_SIZE(s, 16);

This results in a type string that's unchanged from the original
and therefore, won't change versions for symbols that reference
the changed structure.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/gendwarfksyms/dwarf.c            | 14 +++++++++++++-
 scripts/gendwarfksyms/examples/kabi.h    |  7 +++++++
 scripts/gendwarfksyms/examples/kabi_ex.c |  2 ++
 scripts/gendwarfksyms/examples/kabi_ex.h | 22 ++++++++++++++++++++++
 scripts/gendwarfksyms/gendwarfksyms.h    |  1 +
 scripts/gendwarfksyms/kabi.c             | 25 +++++++++++++++++++++++++
 6 files changed, 70 insertions(+), 1 deletion(-)

(limited to 'scripts')

diff --git a/scripts/gendwarfksyms/dwarf.c b/scripts/gendwarfksyms/dwarf.c
index eed247d8abfc..13ea7bf1ae7d 100644
--- a/scripts/gendwarfksyms/dwarf.c
+++ b/scripts/gendwarfksyms/dwarf.c
@@ -228,12 +228,24 @@ static void process_fqn(struct die *cache, Dwarf_Die *die)
 DEFINE_PROCESS_UDATA_ATTRIBUTE(accessibility)
 DEFINE_PROCESS_UDATA_ATTRIBUTE(alignment)
 DEFINE_PROCESS_UDATA_ATTRIBUTE(bit_size)
-DEFINE_PROCESS_UDATA_ATTRIBUTE(byte_size)
 DEFINE_PROCESS_UDATA_ATTRIBUTE(encoding)
 DEFINE_PROCESS_UDATA_ATTRIBUTE(data_bit_offset)
 DEFINE_PROCESS_UDATA_ATTRIBUTE(data_member_location)
 DEFINE_PROCESS_UDATA_ATTRIBUTE(discr_value)
 
+static void process_byte_size_attr(struct die *cache, Dwarf_Die *die)
+{
+	Dwarf_Word value;
+	unsigned long override;
+
+	if (get_udata_attr(die, DW_AT_byte_size, &value)) {
+		if (stable && kabi_get_byte_size(cache->fqn, &override))
+			value = override;
+
+		process_fmt(cache, " byte_size(%" PRIu64 ")", value);
+	}
+}
+
 /* Match functions -- die_match_callback_t */
 #define DEFINE_MATCH(type)                                     \
 	static bool match_##type##_type(Dwarf_Die *die)        \
diff --git a/scripts/gendwarfksyms/examples/kabi.h b/scripts/gendwarfksyms/examples/kabi.h
index 97a5669b083d..86f4428e0479 100644
--- a/scripts/gendwarfksyms/examples/kabi.h
+++ b/scripts/gendwarfksyms/examples/kabi.h
@@ -89,6 +89,13 @@
 #define KABI_ENUMERATOR_VALUE(fqn, field, value) \
 	__KABI_RULE(enumerator_value, fqn field, value)
 
+/*
+ * KABI_BYTE_SIZE(fqn, value)
+ *   Set the byte_size attribute for the struct/union/enum fqn to
+ *   value bytes.
+ */
+#define KABI_BYTE_SIZE(fqn, value) __KABI_RULE(byte_size, fqn, value)
+
 /*
  * KABI_RESERVE
  *   Reserve some "padding" in a structure for use by LTS backports.
diff --git a/scripts/gendwarfksyms/examples/kabi_ex.c b/scripts/gendwarfksyms/examples/kabi_ex.c
index 0b7ffd830541..b73ee5399a59 100644
--- a/scripts/gendwarfksyms/examples/kabi_ex.c
+++ b/scripts/gendwarfksyms/examples/kabi_ex.c
@@ -28,3 +28,5 @@ struct ex2c ex2c;
 struct ex3a ex3a;
 struct ex3b ex3b;
 struct ex3c ex3c;
+
+struct ex4a ex4a;
diff --git a/scripts/gendwarfksyms/examples/kabi_ex.h b/scripts/gendwarfksyms/examples/kabi_ex.h
index 1736e0f65208..092c8cb7bcd7 100644
--- a/scripts/gendwarfksyms/examples/kabi_ex.h
+++ b/scripts/gendwarfksyms/examples/kabi_ex.h
@@ -260,4 +260,26 @@ _Static_assert(sizeof(struct ex3a) == sizeof(struct ex3c), "ex3a size doesn't ma
  * STABLE-NEXT: } byte_size(16)
  */
 
+/*
+ * Example: An ignored field added to an end of a partially opaque struct,
+ * while keeping the byte_size attribute unchanged.
+ */
+
+struct ex4a {
+	unsigned long a;
+	KABI_IGNORE(0, unsigned long b);
+};
+
+/*
+ * This may be safe if the structure allocation is managed by the core kernel
+ * and the layout remains unchanged except for appended new members.
+ */
+KABI_BYTE_SIZE(ex4a, 8);
+
+/*
+ * STABLE:      variable structure_type ex4a {
+ * STABLE-NEXT:   member base_type [[ULONG]] byte_size(8) encoding(7) a data_member_location(0)
+ * STABLE-NEXT: } byte_size(8)
+ */
+
 #endif /* __KABI_EX_H__ */
diff --git a/scripts/gendwarfksyms/gendwarfksyms.h b/scripts/gendwarfksyms/gendwarfksyms.h
index 2feec168bf73..2db49c2ad50e 100644
--- a/scripts/gendwarfksyms/gendwarfksyms.h
+++ b/scripts/gendwarfksyms/gendwarfksyms.h
@@ -287,6 +287,7 @@ void generate_symtypes_and_versions(FILE *file);
  * kabi.c
  */
 
+bool kabi_get_byte_size(const char *fqn, unsigned long *value);
 bool kabi_is_enumerator_ignored(const char *fqn, const char *field);
 bool kabi_get_enumerator_value(const char *fqn, const char *field,
 			       unsigned long *value);
diff --git a/scripts/gendwarfksyms/kabi.c b/scripts/gendwarfksyms/kabi.c
index badf8d46b154..61620ff647bd 100644
--- a/scripts/gendwarfksyms/kabi.c
+++ b/scripts/gendwarfksyms/kabi.c
@@ -54,11 +54,19 @@
  */
 #define KABI_RULE_TAG_ENUMERATOR_VALUE "enumerator_value"
 
+/*
+ * Rule: byte_size
+ * - For the fqn_field in the target field, set the byte_size
+ *   attribute to the value in the value field.
+ */
+#define KABI_RULE_TAG_BYTE_SIZE "byte_size"
+
 enum kabi_rule_type {
 	KABI_RULE_TYPE_UNKNOWN,
 	KABI_RULE_TYPE_DECLONLY,
 	KABI_RULE_TYPE_ENUMERATOR_IGNORE,
 	KABI_RULE_TYPE_ENUMERATOR_VALUE,
+	KABI_RULE_TYPE_BYTE_SIZE,
 };
 
 #define RULE_HASH_BITS 7
@@ -127,6 +135,10 @@ void kabi_read_rules(int fd)
 			.type = KABI_RULE_TYPE_ENUMERATOR_VALUE,
 			.tag = KABI_RULE_TAG_ENUMERATOR_VALUE,
 		},
+		{
+			.type = KABI_RULE_TYPE_BYTE_SIZE,
+			.tag = KABI_RULE_TAG_BYTE_SIZE,
+		},
 	};
 
 	if (!stable)
@@ -308,6 +320,19 @@ bool kabi_get_enumerator_value(const char *fqn, const char *field,
 	return false;
 }
 
+bool kabi_get_byte_size(const char *fqn, unsigned long *value)
+{
+	struct rule *rule;
+
+	rule = find_rule(KABI_RULE_TYPE_BYTE_SIZE, fqn);
+	if (rule) {
+		*value = get_ulong_value(rule->value);
+		return true;
+	}
+
+	return false;
+}
+
 void kabi_free(void)
 {
 	struct hlist_node *tmp;
-- 
cgit v1.2.3


From c9083467f7b97e7c06b7a9038c4f18095329bd37 Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Wed, 7 May 2025 23:14:07 +0000
Subject: gendwarfksyms: Add a kABI rule to override type strings

In rare situations where distributions must make significant
changes to otherwise opaque data structures that have
inadvertently been included in the published ABI, keeping
symbol versions stable using the existing kABI macros can
become tedious.

For example, Android decided to switch to a newer io_uring
implementation in the 5.10 GKI kernel "to resolve a huge number
of potential, and known, problems with the codebase," requiring
"horrible hacks" with genksyms:

  "A number of the io_uring structures get used in other core
  kernel structures, only as "opaque" pointers, so there is
  not any real ABI breakage.  But, due to the visibility of
  the structures going away, the CRC values of many scheduler
  variables and functions were changed."
    -- https://r.android.com/2425293

While these specific changes probably could have been hidden
from gendwarfksyms using the existing kABI macros, this may not
always be the case.

Add a last resort kABI rule that allows distribution
maintainers to fully override a type string for a symbol or a
type. Also add a more informative error message in case we find
a non-existent type references when calculating versions.

Suggested-by: Giuliano Procida <gprocida@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/gendwarfksyms/examples/kabi.h    |  14 +++-
 scripts/gendwarfksyms/examples/kabi_ex.c |   5 ++
 scripts/gendwarfksyms/examples/kabi_ex.h |  79 ++++++++++++++++-
 scripts/gendwarfksyms/gendwarfksyms.h    |   1 +
 scripts/gendwarfksyms/kabi.c             |  25 ++++++
 scripts/gendwarfksyms/types.c            | 140 +++++++++++++++++++++++++++----
 6 files changed, 246 insertions(+), 18 deletions(-)

(limited to 'scripts')

diff --git a/scripts/gendwarfksyms/examples/kabi.h b/scripts/gendwarfksyms/examples/kabi.h
index 86f4428e0479..170733a3fba4 100644
--- a/scripts/gendwarfksyms/examples/kabi.h
+++ b/scripts/gendwarfksyms/examples/kabi.h
@@ -37,11 +37,14 @@
 #define __stringify(x...) __stringify_1(x)
 #endif
 
-#define __KABI_RULE(hint, target, value)                             \
+#define ___KABI_RULE(hint, target, value)                            \
 	static const char __PASTE(__gendwarfksyms_rule_,             \
 				  __COUNTER__)[] __used __aligned(1) \
 		__section(".discard.gendwarfksyms.kabi_rules") =     \
-			"1\0" #hint "\0" #target "\0" #value
+			"1\0" #hint "\0" target "\0" value
+
+#define __KABI_RULE(hint, target, value) \
+	___KABI_RULE(hint, #target, #value)
 
 #define __KABI_NORMAL_SIZE_ALIGN(_orig, _new)                                             \
 	union {                                                                           \
@@ -96,6 +99,13 @@
  */
 #define KABI_BYTE_SIZE(fqn, value) __KABI_RULE(byte_size, fqn, value)
 
+/*
+ * KABI_TYPE_STRING(type, str)
+ *   For the given type, override the type string used in symtypes
+ *   output and version calculation with str.
+ */
+#define KABI_TYPE_STRING(type, str) ___KABI_RULE(type_string, type, str)
+
 /*
  * KABI_RESERVE
  *   Reserve some "padding" in a structure for use by LTS backports.
diff --git a/scripts/gendwarfksyms/examples/kabi_ex.c b/scripts/gendwarfksyms/examples/kabi_ex.c
index b73ee5399a59..1f799eb7c756 100644
--- a/scripts/gendwarfksyms/examples/kabi_ex.c
+++ b/scripts/gendwarfksyms/examples/kabi_ex.c
@@ -30,3 +30,8 @@ struct ex3b ex3b;
 struct ex3c ex3c;
 
 struct ex4a ex4a;
+
+struct ex5a ex5a;
+struct ex5b ex5b;
+
+int ex6a;
diff --git a/scripts/gendwarfksyms/examples/kabi_ex.h b/scripts/gendwarfksyms/examples/kabi_ex.h
index 092c8cb7bcd7..785b211d9c58 100644
--- a/scripts/gendwarfksyms/examples/kabi_ex.h
+++ b/scripts/gendwarfksyms/examples/kabi_ex.h
@@ -21,6 +21,12 @@
  * 	./gendwarfksyms --stable --dump-dies \
  * 		examples/kabi_ex.o 2>&1 >/dev/null | \
  * 	FileCheck examples/kabi_ex.h --check-prefix=STABLE
+
+ * $ nm examples/kabi_ex.o | awk '{ print $NF }' | \
+ * 	./gendwarfksyms --stable --dump-versions \
+ * 		examples/kabi_ex.o 2>&1 >/dev/null | \
+ * 	sort | \
+ * 	FileCheck examples/kabi_ex.h --check-prefix=VERSIONS
  */
 
 #ifndef __KABI_EX_H__
@@ -170,7 +176,7 @@ struct ex2a {
 /*
  * STABLE:      variable structure_type ex2a {
  * STABLE-NEXT:   member base_type int byte_size(4) encoding(5) a data_member_location(0) ,
- * STABLE-NEXT:   member base_type [[ULONG:long unsigned int|unsigned long]] byte_size(8) encoding(7) b data_member_location(8)
+ * STABLE-NEXT:   member base_type [[ULONG]] byte_size(8) encoding(7) b data_member_location(8)
  * STABLE-NEXT:   member base_type int byte_size(4) encoding(5) c data_member_location(16) ,
  * STABLE-NEXT:   member base_type [[ULONG]] byte_size(8) encoding(7) d data_member_location(24)
  * STABLE-NEXT: } byte_size(32)
@@ -227,7 +233,7 @@ struct ex3a {
 
 /*
  * STABLE:      variable structure_type ex3a {
- * STABLE-NEXT:   member base_type [[ULONG:long unsigned int|unsigned long]] byte_size(8) encoding(7) a data_member_location(0)
+ * STABLE-NEXT:   member base_type [[ULONG]] byte_size(8) encoding(7) a data_member_location(0)
  * STABLE-NEXT:   member base_type [[ULONG]] byte_size(8) encoding(7) unused data_member_location(8)
  * STABLE-NEXT: } byte_size(16)
  */
@@ -282,4 +288,73 @@ KABI_BYTE_SIZE(ex4a, 8);
  * STABLE-NEXT: } byte_size(8)
  */
 
+/*
+ * Example: A type string override.
+ */
+
+struct ex5a {
+	unsigned long a;
+};
+
+/*
+ * This may be safe if the structure is fully opaque to modules, even though
+ * its definition has inadvertently become part of the ABI.
+ */
+KABI_TYPE_STRING(
+	"s#ex5a",
+	"structure_type ex5a { member pointer_type { s#ex4a } byte_size(8) p data_member_location(0) } byte_size(8)");
+
+/*
+ * Make sure the fully expanded type string includes ex4a.
+ *
+ * VERSIONS:      ex5a variable structure_type ex5a {
+ * VERSIONS-SAME:   member pointer_type {
+ * VERSIONS-SAME:     structure_type ex4a {
+ * VERSIONS-SAME:       member base_type [[ULONG:long unsigned int|unsigned long]] byte_size(8) encoding(7) a data_member_location(0)
+ * VERSIONS-SAME:     } byte_size(8)
+ * VERSIONS-SAME:   } byte_size(8) p data_member_location(0)
+ * VERSIONS-SAME: } byte_size(8)
+ */
+
+/*
+ * Example: A type string definition for a non-existent type.
+ */
+
+struct ex5b {
+	unsigned long a;
+};
+
+/* Replace the type string for struct ex5b */
+KABI_TYPE_STRING(
+	"s#ex5b",
+	"structure_type ex5b { member pointer_type { s#ex5c } byte_size(8) p data_member_location(0) } byte_size(8)");
+
+/* Define a type string for a non-existent struct ex5c */
+KABI_TYPE_STRING(
+	"s#ex5c",
+	"structure_type ex5c { member base_type int byte_size(4) encoding(5) n data_member_location(0) } byte_size(8)");
+
+/*
+ * Make sure the fully expanded type string includes the definition for ex5c.
+ *
+ * VERSIONS:      ex5b variable structure_type ex5b {
+ * VERSIONS-SAME:   member pointer_type {
+ * VERSIONS-SAME:     structure_type ex5c {
+ * VERSIONS-SAME:       member base_type int byte_size(4) encoding(5) n data_member_location(0)
+ * VERSIONS-SAME:     } byte_size(8)
+ * VERSIONS-SAME:   } byte_size(8) p data_member_location(0)
+ * VERSIONS-SAME: } byte_size(8)
+ */
+
+/*
+ * Example: A type string override for a symbol.
+ */
+
+KABI_TYPE_STRING("ex6a", "variable s#ex5c");
+
+/*
+ * VERSIONS:      ex6a variable structure_type ex5c {
+ * VERSIONS-SAME:   member base_type int byte_size(4) encoding(5) n data_member_location(0)
+ * VERSIONS-SAME: } byte_size(8)
+ */
 #endif /* __KABI_EX_H__ */
diff --git a/scripts/gendwarfksyms/gendwarfksyms.h b/scripts/gendwarfksyms/gendwarfksyms.h
index 2db49c2ad50e..7dd03ffe0c5c 100644
--- a/scripts/gendwarfksyms/gendwarfksyms.h
+++ b/scripts/gendwarfksyms/gendwarfksyms.h
@@ -292,6 +292,7 @@ bool kabi_is_enumerator_ignored(const char *fqn, const char *field);
 bool kabi_get_enumerator_value(const char *fqn, const char *field,
 			       unsigned long *value);
 bool kabi_is_declonly(const char *fqn);
+bool kabi_get_type_string(const char *type, const char **str);
 
 void kabi_read_rules(int fd);
 void kabi_free(void);
diff --git a/scripts/gendwarfksyms/kabi.c b/scripts/gendwarfksyms/kabi.c
index 61620ff647bd..b3ade713778f 100644
--- a/scripts/gendwarfksyms/kabi.c
+++ b/scripts/gendwarfksyms/kabi.c
@@ -61,12 +61,20 @@
  */
 #define KABI_RULE_TAG_BYTE_SIZE "byte_size"
 
+/*
+ * Rule: type_string
+ * - For the type reference in the fqn field, use the type string
+ *   in the value field.
+ */
+#define KABI_RULE_TAG_TYPE_STRING "type_string"
+
 enum kabi_rule_type {
 	KABI_RULE_TYPE_UNKNOWN,
 	KABI_RULE_TYPE_DECLONLY,
 	KABI_RULE_TYPE_ENUMERATOR_IGNORE,
 	KABI_RULE_TYPE_ENUMERATOR_VALUE,
 	KABI_RULE_TYPE_BYTE_SIZE,
+	KABI_RULE_TYPE_TYPE_STRING,
 };
 
 #define RULE_HASH_BITS 7
@@ -139,6 +147,10 @@ void kabi_read_rules(int fd)
 			.type = KABI_RULE_TYPE_BYTE_SIZE,
 			.tag = KABI_RULE_TAG_BYTE_SIZE,
 		},
+		{
+			.type = KABI_RULE_TYPE_TYPE_STRING,
+			.tag = KABI_RULE_TAG_TYPE_STRING,
+		},
 	};
 
 	if (!stable)
@@ -333,6 +345,19 @@ bool kabi_get_byte_size(const char *fqn, unsigned long *value)
 	return false;
 }
 
+bool kabi_get_type_string(const char *type, const char **str)
+{
+	struct rule *rule;
+
+	rule = find_rule(KABI_RULE_TYPE_TYPE_STRING, type);
+	if (rule) {
+		*str = rule->value;
+		return true;
+	}
+
+	return false;
+}
+
 void kabi_free(void)
 {
 	struct hlist_node *tmp;
diff --git a/scripts/gendwarfksyms/types.c b/scripts/gendwarfksyms/types.c
index 6f37289104ff..39ce1770e463 100644
--- a/scripts/gendwarfksyms/types.c
+++ b/scripts/gendwarfksyms/types.c
@@ -100,7 +100,7 @@ static void type_expansion_append(struct type_expansion *type, const char *s,
 #define TYPE_HASH_BITS 12
 static HASHTABLE_DEFINE(type_map, 1 << TYPE_HASH_BITS);
 
-static int type_map_get(const char *name, struct type_expansion **res)
+static int __type_map_get(const char *name, struct type_expansion **res)
 {
 	struct type_expansion *e;
 
@@ -114,11 +114,12 @@ static int type_map_get(const char *name, struct type_expansion **res)
 	return -1;
 }
 
-static void type_map_add(const char *name, struct type_expansion *type)
+static struct type_expansion *type_map_add(const char *name,
+					   struct type_expansion *type)
 {
 	struct type_expansion *e;
 
-	if (type_map_get(name, &e)) {
+	if (__type_map_get(name, &e)) {
 		e = xmalloc(sizeof(struct type_expansion));
 		type_expansion_init(e);
 		e->name = xstrdup(name);
@@ -130,7 +131,7 @@ static void type_map_add(const char *name, struct type_expansion *type)
 	} else {
 		/* Use the longest available expansion */
 		if (type->len <= e->len)
-			return;
+			return e;
 
 		type_list_free(&e->expanded);
 
@@ -148,6 +149,34 @@ static void type_map_add(const char *name, struct type_expansion *type)
 		type_list_write(&e->expanded, stderr);
 		checkp(fputs("\n", stderr));
 	}
+
+	return e;
+}
+
+static void type_parse(const char *name, const char *str,
+		       struct type_expansion *type);
+
+static int type_map_get(const char *name, struct type_expansion **res)
+{
+	struct type_expansion type;
+	const char *override;
+
+	if (!__type_map_get(name, res))
+		return 0;
+
+	/*
+	 * If die_map didn't contain a type, we might still have
+	 * a type_string kABI rule that defines it.
+	 */
+	if (stable && kabi_get_type_string(name, &override)) {
+		type_expansion_init(&type);
+		type_parse(name, override, &type);
+		*res = type_map_add(name, &type);
+		type_expansion_free(&type);
+		return 0;
+	}
+
+	return -1;
 }
 
 static void type_map_write(FILE *file)
@@ -267,15 +296,18 @@ static char *get_type_name(struct die *cache)
 	return name;
 }
 
-static void __calculate_version(struct version *version, struct list_head *list)
+static void __calculate_version(struct version *version,
+				struct type_expansion *type)
 {
 	struct type_list_entry *entry;
 	struct type_expansion *e;
 
 	/* Calculate a CRC over an expanded type string */
-	list_for_each_entry(entry, list, list) {
+	list_for_each_entry(entry, &type->expanded, list) {
 		if (is_type_prefix(entry->str)) {
-			check(type_map_get(entry->str, &e));
+			if (type_map_get(entry->str, &e))
+				error("unknown type reference to '%s' when expanding '%s'",
+				      entry->str, type->name);
 
 			/*
 			 * It's sufficient to expand each type reference just
@@ -285,7 +317,7 @@ static void __calculate_version(struct version *version, struct list_head *list)
 				version_add(version, entry->str);
 			} else {
 				cache_mark_expanded(&expansion_cache, e);
-				__calculate_version(version, &e->expanded);
+				__calculate_version(version, e);
 			}
 		} else {
 			version_add(version, entry->str);
@@ -293,10 +325,11 @@ static void __calculate_version(struct version *version, struct list_head *list)
 	}
 }
 
-static void calculate_version(struct version *version, struct list_head *list)
+static void calculate_version(struct version *version,
+			      struct type_expansion *type)
 {
 	version_init(version);
-	__calculate_version(version, list);
+	__calculate_version(version, type);
 	cache_free(&expansion_cache);
 }
 
@@ -372,9 +405,80 @@ static void type_expand(struct die *cache, struct type_expansion *type,
 	cache_free(&expansion_cache);
 }
 
+static void type_parse(const char *name, const char *str,
+		       struct type_expansion *type)
+{
+	char *fragment;
+	size_t start = 0;
+	size_t end;
+	size_t pos;
+
+	if (!*str)
+		error("empty type string override for '%s'", name);
+
+	type_expansion_init(type);
+
+	for (pos = 0; str[pos]; ++pos) {
+		bool empty;
+		char marker = ' ';
+
+		if (!is_type_prefix(&str[pos]))
+			continue;
+
+		end = pos + 2;
+
+		/*
+		 * Find the end of the type reference. If the type name contains
+		 * spaces, it must be in single quotes.
+		 */
+		if (str[end] == '\'') {
+			marker = '\'';
+			++end;
+		}
+		while (str[end] && str[end] != marker)
+			++end;
+
+		/* Check that we have a non-empty type name */
+		if (marker == '\'') {
+			if (str[end] != marker)
+				error("incomplete %c# type reference for '%s' (string : '%s')",
+				      str[pos], name, str);
+			empty = end == pos + 3;
+			++end;
+		} else {
+			empty = end == pos + 2;
+		}
+		if (empty)
+			error("empty %c# type name for '%s' (string: '%s')",
+			      str[pos], name, str);
+
+		/* Append the part of the string before the type reference */
+		if (pos > start) {
+			fragment = xstrndup(&str[start], pos - start);
+			type_expansion_append(type, fragment, fragment);
+		}
+
+		/*
+		 * Append the type reference -- note that if the reference
+		 * is invalid, i.e. points to a non-existent type, we will
+		 * print out an error when calculating versions.
+		 */
+		fragment = xstrndup(&str[pos], end - pos);
+		type_expansion_append(type, fragment, fragment);
+
+		start = end;
+		pos = end - 1;
+	}
+
+	/* Append the rest of the type string, if there's any left */
+	if (str[start])
+		type_expansion_append(type, &str[start], NULL);
+}
+
 static void expand_type(struct die *cache, void *arg)
 {
 	struct type_expansion type;
+	const char *override;
 	char *name;
 
 	if (cache->mapped)
@@ -399,9 +503,13 @@ static void expand_type(struct die *cache, void *arg)
 		return;
 
 	debug("%s", name);
-	type_expand(cache, &type, true);
-	type_map_add(name, &type);
 
+	if (stable && kabi_get_type_string(name, &override))
+		type_parse(name, override, &type);
+	else
+		type_expand(cache, &type, true);
+
+	type_map_add(name, &type);
 	type_expansion_free(&type);
 	free(name);
 }
@@ -410,6 +518,7 @@ static void expand_symbol(struct symbol *sym, void *arg)
 {
 	struct type_expansion type;
 	struct version version;
+	const char *override;
 	struct die *cache;
 
 	/*
@@ -423,11 +532,14 @@ static void expand_symbol(struct symbol *sym, void *arg)
 	if (__die_map_get(sym->die_addr, DIE_SYMBOL, &cache))
 		return; /* We'll warn about missing CRCs later. */
 
-	type_expand(cache, &type, false);
+	if (stable && kabi_get_type_string(sym->name, &override))
+		type_parse(sym->name, override, &type);
+	else
+		type_expand(cache, &type, false);
 
 	/* If the symbol already has a version, don't calculate it again. */
 	if (sym->state != SYMBOL_PROCESSED) {
-		calculate_version(&version, &type.expanded);
+		calculate_version(&version, &type);
 		symbol_set_crc(sym, version.crc);
 		debug("%s = %lx", sym->name, version.crc);
 
-- 
cgit v1.2.3


From 8f81d8529e19c84b014e4239d2012373274d138d Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Wed, 14 May 2025 14:46:33 +0900
Subject: kbuild: move kbuild syntax processing to scripts/Makefile.build

scripts/Makefile.lib is included by the following Makefiles:

  scripts/Makefile.build
  scripts/Makefile.modfinal
  scripts/Makefile.package
  scripts/Makefile.vmlinux
  scripts/Makefile.vmlinux_o

However, the last four do not need to process Kbuild syntax such as
obj-*, lib-*, subdir-*, etc.

Move the relevant code to scripts/Makefile.build.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas.schier@linux.dev>
---
 scripts/Makefile.build | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++
 scripts/Makefile.lib   | 84 --------------------------------------------------
 2 files changed, 84 insertions(+), 84 deletions(-)

(limited to 'scripts')

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 13dcd86e74ca..8d8252229895 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -37,6 +37,90 @@ include $(srctree)/scripts/Makefile.compiler
 include $(kbuild-file)
 include $(srctree)/scripts/Makefile.lib
 
+# flags that take effect in current and sub directories
+KBUILD_AFLAGS += $(subdir-asflags-y)
+KBUILD_CFLAGS += $(subdir-ccflags-y)
+KBUILD_RUSTFLAGS += $(subdir-rustflags-y)
+
+# Figure out what we need to build from the various variables
+# ===========================================================================
+
+# When an object is listed to be built compiled-in and modular,
+# only build the compiled-in version
+obj-m := $(filter-out $(obj-y),$(obj-m))
+
+# Libraries are always collected in one lib file.
+# Filter out objects already built-in
+lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
+
+# Subdirectories we need to descend into
+subdir-ym := $(sort $(subdir-y) $(subdir-m) \
+			$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
+
+# Handle objects in subdirs:
+# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
+#   foo/modules.order
+# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
+#
+# Generate modules.order to determine modorder. Unfortunately, we don't have
+# information about ordering between -y and -m subdirs. Just put -y's first.
+
+ifdef need-modorder
+obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
+else
+obj-m := $(filter-out %/, $(obj-m))
+endif
+
+ifdef need-builtin
+obj-y		:= $(patsubst %/, %/built-in.a, $(obj-y))
+else
+obj-y		:= $(filter-out %/, $(obj-y))
+endif
+
+# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
+suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
+# List composite targets that are constructed by combining other targets
+multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
+# List primitive targets that are compiled from source files
+real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
+
+# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
+multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
+multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
+multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
+
+# Replace multi-part objects by their individual parts,
+# including built-in.a from subdirectories
+real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
+real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
+
+always-y += $(always-m)
+
+# hostprogs-always-y += foo
+# ... is a shorthand for
+# hostprogs += foo
+# always-y  += foo
+hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
+always-y += $(hostprogs-always-y) $(hostprogs-always-m)
+
+# userprogs-always-y is likewise.
+userprogs += $(userprogs-always-y) $(userprogs-always-m)
+always-y += $(userprogs-always-y) $(userprogs-always-m)
+
+# Add subdir path
+
+ifneq ($(obj),.)
+extra-y		:= $(addprefix $(obj)/, $(extra-y))
+always-y	:= $(addprefix $(obj)/, $(always-y))
+targets		:= $(addprefix $(obj)/, $(targets))
+obj-m		:= $(addprefix $(obj)/, $(obj-m))
+lib-y		:= $(addprefix $(obj)/, $(lib-y))
+real-obj-y	:= $(addprefix $(obj)/, $(real-obj-y))
+real-obj-m	:= $(addprefix $(obj)/, $(real-obj-m))
+multi-obj-m	:= $(addprefix $(obj)/, $(multi-obj-m))
+subdir-ym	:= $(addprefix $(obj)/, $(subdir-ym))
+endif
+
 ifndef obj
 $(warning kbuild: Makefile.build is included improperly)
 endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 2fe73cda0bdd..2d3a8470cf39 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -1,89 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 
-# flags that take effect in current and sub directories
-KBUILD_AFLAGS += $(subdir-asflags-y)
-KBUILD_CFLAGS += $(subdir-ccflags-y)
-KBUILD_RUSTFLAGS += $(subdir-rustflags-y)
-
-# Figure out what we need to build from the various variables
-# ===========================================================================
-
-# When an object is listed to be built compiled-in and modular,
-# only build the compiled-in version
-obj-m := $(filter-out $(obj-y),$(obj-m))
-
-# Libraries are always collected in one lib file.
-# Filter out objects already built-in
-lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
-
-# Subdirectories we need to descend into
-subdir-ym := $(sort $(subdir-y) $(subdir-m) \
-			$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
-
-# Handle objects in subdirs:
-# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
-#   foo/modules.order
-# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
-#
-# Generate modules.order to determine modorder. Unfortunately, we don't have
-# information about ordering between -y and -m subdirs. Just put -y's first.
-
-ifdef need-modorder
-obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
-else
-obj-m := $(filter-out %/, $(obj-m))
-endif
-
-ifdef need-builtin
-obj-y		:= $(patsubst %/, %/built-in.a, $(obj-y))
-else
-obj-y		:= $(filter-out %/, $(obj-y))
-endif
-
-# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
-suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
-# List composite targets that are constructed by combining other targets
-multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
-# List primitive targets that are compiled from source files
-real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
-
-# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
-multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
-multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
-multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
-
-# Replace multi-part objects by their individual parts,
-# including built-in.a from subdirectories
-real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
-real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
-
-always-y += $(always-m)
-
-# hostprogs-always-y += foo
-# ... is a shorthand for
-# hostprogs += foo
-# always-y  += foo
-hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
-always-y += $(hostprogs-always-y) $(hostprogs-always-m)
-
-# userprogs-always-y is likewise.
-userprogs += $(userprogs-always-y) $(userprogs-always-m)
-always-y += $(userprogs-always-y) $(userprogs-always-m)
-
-# Add subdir path
-
-ifneq ($(obj),.)
-extra-y		:= $(addprefix $(obj)/,$(extra-y))
-always-y	:= $(addprefix $(obj)/,$(always-y))
-targets		:= $(addprefix $(obj)/,$(targets))
-obj-m		:= $(addprefix $(obj)/,$(obj-m))
-lib-y		:= $(addprefix $(obj)/,$(lib-y))
-real-obj-y	:= $(addprefix $(obj)/,$(real-obj-y))
-real-obj-m	:= $(addprefix $(obj)/,$(real-obj-m))
-multi-obj-m	:= $(addprefix $(obj)/, $(multi-obj-m))
-subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))
-endif
-
 # Finds the multi-part object the current object will be linked into.
 # If the object belongs to two or more multi-part objects, list them all.
 modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
-- 
cgit v1.2.3


From 9c036cfbb75bb58ecce589f547fdb8af153493a6 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 22 May 2025 16:17:20 +0900
Subject: modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time

Explicitly adding MODULE_IMPORT_NS("module:...") is not allowed.

Currently, this is only checked at run time. That is, when such a
module is loaded, an error message like the following is shown:

  foo: module tries to import module namespace: module:bar

Obviously, checking this at compile time improves usability.

In such a case, modpost will report the following error at compile time:

  ERROR: modpost: foo: explicitly importing namespace "module:bar" is not allowed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/mod/modpost.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'scripts')

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 16a69a129805..5ca7c268294e 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -28,6 +28,8 @@
 #include "modpost.h"
 #include "../../include/linux/license.h"
 
+#define MODULE_NS_PREFIX "module:"
+
 static bool module_enabled;
 /* Are we using CONFIG_MODVERSIONS? */
 static bool modversions;
@@ -1597,8 +1599,13 @@ static void read_symbols(const char *modname)
 
 		for (namespace = get_modinfo(&info, "import_ns");
 		     namespace;
-		     namespace = get_next_modinfo(&info, "import_ns", namespace))
+		     namespace = get_next_modinfo(&info, "import_ns", namespace)) {
+			if (strstarts(namespace, MODULE_NS_PREFIX))
+				error("%s: explicitly importing namespace \"%s\" is not allowed.\n",
+				      mod->name, namespace);
+
 			add_namespace(&mod->imported_namespaces, namespace);
+		}
 
 		if (!get_modinfo(&info, "description"))
 			warn("missing MODULE_DESCRIPTION() in %s\n", modname);
-- 
cgit v1.2.3


From 0f57c75973bedc08a865b06ce1b73ae5b54477c0 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Wed, 28 May 2025 02:56:15 +0900
Subject: kconfig: introduce menu type enum

Currently, menu->prompt->type is checked to distinguish "comment"
(P_COMMENT) and "menu" (P_MENU) entries from regular "config" entries.
This is odd because P_COMMENT and P_MENU are not properties.

This commit introduces menu type enum to distinguish menu types more
naturally.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/expr.h   | 11 +++++++++++
 scripts/kconfig/lkc.h    |  2 +-
 scripts/kconfig/menu.c   |  5 +++--
 scripts/kconfig/parser.y | 12 ++++++------
 4 files changed, 21 insertions(+), 9 deletions(-)

(limited to 'scripts')

diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h
index 21578dcd4292..fe2231e0e6a4 100644
--- a/scripts/kconfig/expr.h
+++ b/scripts/kconfig/expr.h
@@ -205,15 +205,26 @@ struct property {
 	for (st = sym->prop; st; st = st->next) \
 		if (st->text)
 
+enum menu_type {
+	M_CHOICE,  // "choice"
+	M_COMMENT, // "comment"
+	M_IF,      // "if"
+	M_MENU,    // "mainmenu", "menu", "menuconfig"
+	M_NORMAL,  // others, i.e., "config"
+};
+
 /*
  * Represents a node in the menu tree, as seen in e.g. menuconfig (though used
  * for all front ends). Each symbol, menu, etc. defined in the Kconfig files
  * gets a node. A symbol defined in multiple locations gets one node at each
  * location.
  *
+ * @type: type of the menu entry
  * @choice_members: list of choice members with priority.
  */
 struct menu {
+	enum menu_type type;
+
 	/* The next menu node at the same level */
 	struct menu *next;
 
diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index b8ebc3094a23..fbc907f75eac 100644
--- a/scripts/kconfig/lkc.h
+++ b/scripts/kconfig/lkc.h
@@ -81,7 +81,7 @@ void _menu_init(void);
 void menu_warn(const struct menu *menu, const char *fmt, ...);
 struct menu *menu_add_menu(void);
 void menu_end_menu(void);
-void menu_add_entry(struct symbol *sym);
+void menu_add_entry(struct symbol *sym, enum menu_type type);
 void menu_add_dep(struct expr *dep);
 void menu_add_visibility(struct expr *dep);
 struct property *menu_add_prompt(enum prop_type type, const char *prompt,
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 6587ac86d0d5..7d48a692bd27 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -15,7 +15,7 @@
 
 static const char nohelp_text[] = "There is no help available for this option.";
 
-struct menu rootmenu;
+struct menu rootmenu = { .type = M_MENU };
 static struct menu **last_entry_ptr;
 
 /**
@@ -65,12 +65,13 @@ void _menu_init(void)
 	last_entry_ptr = &rootmenu.list;
 }
 
-void menu_add_entry(struct symbol *sym)
+void menu_add_entry(struct symbol *sym, enum menu_type type)
 {
 	struct menu *menu;
 
 	menu = xmalloc(sizeof(*menu));
 	memset(menu, 0, sizeof(*menu));
+	menu->type = type;
 	menu->sym = sym;
 	menu->parent = current_menu;
 	menu->filename = cur_filename;
diff --git a/scripts/kconfig/parser.y b/scripts/kconfig/parser.y
index 68372d3ff325..e9c3c664e925 100644
--- a/scripts/kconfig/parser.y
+++ b/scripts/kconfig/parser.y
@@ -139,7 +139,7 @@ stmt_list_in_choice:
 
 config_entry_start: T_CONFIG nonconst_symbol T_EOL
 {
-	menu_add_entry($2);
+	menu_add_entry($2, M_NORMAL);
 	printd(DEBUG_PARSE, "%s:%d:config %s\n", cur_filename, cur_lineno, $2->name);
 };
 
@@ -173,7 +173,7 @@ config_stmt: config_entry_start config_option_list
 
 menuconfig_entry_start: T_MENUCONFIG nonconst_symbol T_EOL
 {
-	menu_add_entry($2);
+	menu_add_entry($2, M_MENU);
 	printd(DEBUG_PARSE, "%s:%d:menuconfig %s\n", cur_filename, cur_lineno, $2->name);
 };
 
@@ -246,7 +246,7 @@ choice: T_CHOICE T_EOL
 {
 	struct symbol *sym = sym_lookup(NULL, 0);
 
-	menu_add_entry(sym);
+	menu_add_entry(sym, M_CHOICE);
 	menu_set_type(S_BOOLEAN);
 	INIT_LIST_HEAD(&current_entry->choice_members);
 
@@ -315,7 +315,7 @@ default:
 if_entry: T_IF expr T_EOL
 {
 	printd(DEBUG_PARSE, "%s:%d:if\n", cur_filename, cur_lineno);
-	menu_add_entry(NULL);
+	menu_add_entry(NULL, M_IF);
 	menu_add_dep($2);
 	$$ = menu_add_menu();
 };
@@ -338,7 +338,7 @@ if_stmt_in_choice: if_entry stmt_list_in_choice if_end
 
 menu: T_MENU T_WORD_QUOTE T_EOL
 {
-	menu_add_entry(NULL);
+	menu_add_entry(NULL, M_MENU);
 	menu_add_prompt(P_MENU, $2, NULL);
 	printd(DEBUG_PARSE, "%s:%d:menu\n", cur_filename, cur_lineno);
 };
@@ -376,7 +376,7 @@ source_stmt: T_SOURCE T_WORD_QUOTE T_EOL
 
 comment: T_COMMENT T_WORD_QUOTE T_EOL
 {
-	menu_add_entry(NULL);
+	menu_add_entry(NULL, M_COMMENT);
 	menu_add_prompt(P_COMMENT, $2, NULL);
 	printd(DEBUG_PARSE, "%s:%d:comment\n", cur_filename, cur_lineno);
 };
-- 
cgit v1.2.3


From a503a313108e26402151f25c1f2628ec91bda605 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Fri, 30 May 2025 04:46:33 +0900
Subject: scripts/tags.sh: allow to use alternative ctags implementation

Some ctags implementations are available. With this change, You can
specify your favorite one with CTAGS environment variable.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/tags.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'scripts')

diff --git a/scripts/tags.sh b/scripts/tags.sh
index 98680e9cd7be..99ce427d9a69 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -344,7 +344,7 @@ case "$1" in
 
 	"tags")
 		rm -f tags
-		xtags ctags
+		xtags ${CTAGS:-ctags}
 		remove_structs=y
 		;;
 
-- 
cgit v1.2.3


From 89e7fecf5ce2e85a323e58f09aa808218a37079a Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sun, 1 Jun 2025 22:31:27 +0900
Subject: kbuild: move W=1 check for scripts/misc-check to top-level Makefile

This script is executed only when ${KBUILD_EXTRA_WARN} contains 1.
Move this check to the top-level Makefile to allow more checks to be
easily added to this script.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
---
 Makefile           | 3 +++
 scripts/misc-check | 9 +--------
 2 files changed, 4 insertions(+), 8 deletions(-)

(limited to 'scripts')

diff --git a/Makefile b/Makefile
index 9a104f02ce25..fe2f1cb4d9b7 100644
--- a/Makefile
+++ b/Makefile
@@ -1827,9 +1827,12 @@ rustfmtcheck: rustfmt
 # Misc
 # ---------------------------------------------------------------------------
 
+# Run misc checks when ${KBUILD_EXTRA_WARN} contains 1
 PHONY += misc-check
+ifneq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
 misc-check:
 	$(Q)$(srctree)/scripts/misc-check
+endif
 
 all: misc-check
 
diff --git a/scripts/misc-check b/scripts/misc-check
index d40d5484e0c5..f37b2f6931cc 100755
--- a/scripts/misc-check
+++ b/scripts/misc-check
@@ -3,15 +3,8 @@
 
 set -e
 
-# Detect files that are tracked but ignored by git. This is checked only when
-# ${KBUILD_EXTRA_WARN} contains 1, git is installed, and the source tree is
-# tracked by git.
+# Detect files that are tracked but ignored by git.
 check_tracked_ignored_files () {
-	case "${KBUILD_EXTRA_WARN}" in
-	*1*) ;;
-	*) return;;
-	esac
-
 	git -C ${srctree:-.} ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
 		sed 's/$/: warning: ignored by one of the .gitignore files/' >&2
 }
-- 
cgit v1.2.3


From 3a44052b728e5d96ea425f908e71926364a12f11 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sun, 1 Jun 2025 22:31:28 +0900
Subject: scripts/misc-check: add double-quotes to satisfy shellcheck

In scripts/misc-check line 8:
        git -C ${srctree:-.} ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
               ^-----------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/misc-check | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'scripts')

diff --git a/scripts/misc-check b/scripts/misc-check
index f37b2f6931cc..21551d721079 100755
--- a/scripts/misc-check
+++ b/scripts/misc-check
@@ -5,7 +5,7 @@ set -e
 
 # Detect files that are tracked but ignored by git.
 check_tracked_ignored_files () {
-	git -C ${srctree:-.} ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
+	git -C "${srctree:-.}" ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
 		sed 's/$/: warning: ignored by one of the .gitignore files/' >&2
 }
 
-- 
cgit v1.2.3


From a934a57a42f64a40705202f84144b1a29b29f910 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sun, 1 Jun 2025 22:31:29 +0900
Subject: scripts/misc-check: check missing #include <linux/export.h> when W=1

The problem was described in commit 5b20755b7780 ("init: move THIS_MODULE
from <linux/export.h> to <linux/init.h>").

To summarize it again here: <linux/export.h> is included by most C files,
even though only some of them actually export symbols. This is because
some headers, such as include/linux/{module.h,linkage}, needlessly
include <linux/export.h>.

I have added a more detailed explanation in the comments of
scripts/misc-check.

This problem will be fixed in two steps:

 1. Add #include <linux/export.h> directly to C files that use
    EXPORT_SYMBOL()
 2. Remove #include <linux/export.h> from header files that do not use
    EXPORT_SYMBOL()

This commit addresses step 1; scripts/misc-check will warn about *.[ch]
files that use EXPORT_SYMBOL() but do not include <linux/export.h>.
This check is only triggered when the kernel is built with W=1.

We need to fix 4000+ files. I hope others will help with this effort.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/misc-check | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

(limited to 'scripts')

diff --git a/scripts/misc-check b/scripts/misc-check
index 21551d721079..7cb61841a125 100755
--- a/scripts/misc-check
+++ b/scripts/misc-check
@@ -9,4 +9,47 @@ check_tracked_ignored_files () {
 		sed 's/$/: warning: ignored by one of the .gitignore files/' >&2
 }
 
+# Check for missing #include <linux/export.h>
+#
+# The rule for including <linux/export.h> is very simple:
+# Include <linux/export.h> only when you use EXPORT_SYMBOL(). That's it.
+#
+# However, some headers include <linux/export.h> even though they are completely
+# unrelated to EXPORT_SYMBOL().
+#
+# One example is include/linux/module.h. Please note <linux/module.h> and
+# <linux/export.h> are orthogonal. <linux/module.h> should be included by files
+# that can be compiled as modules. In other words, <linux/module.h> should be
+# included by EXPORT_SYMBOL consumers. In contrast, <linux/export.h> should be
+# included from EXPORT_SYMBOL providers, which may or may not be modular.
+# Hence, include/linux/module.h should *not* include <linux/export.h>.
+#
+# Another example is include/linux/linkage.h, which is completely unrelated to
+# EXPORT_SYMBOL(). Worse, it is included by most C files, which means, most C
+# files end up including <linux/export.h>, even though only some of them
+# actually export symbols. Hence, include/linux/linkage.h should *not* include
+# <linux/export.h>.
+#
+# Before fixing such headers, we must ensure that C files using EXPORT_SYMBOL()
+# include <linux/export.h> directly, since many C files currently rely on
+# <linux/export.h> being included indirectly (likely, via <linux/linkage> etc.).
+#
+# Therefore, this check.
+#
+# The problem is simple - the warned files use EXPORT_SYMBOL(), but do not
+# include <linux/export.h>. Please add #include <linux/export.h> to them.
+#
+# If the included headers are sorted alphabetically, please insert
+# <linux/export.h> in the appropriate position to maintain the sort order.
+# For this reason, this script only checks missing <linux/export.h>, but
+# does not automatically fix it.
+check_missing_include_linux_export_h () {
+
+	git -C "${srctree:-.}" grep --files-with-matches -E 'EXPORT_SYMBOL((_NS)?(_GPL)?|_GPL_FOR_MODULES)\(.*\)' \
+	    -- '*.[ch]' :^tools/ :^include/linux/export.h |
+	xargs -r git -C "${srctree:-.}" grep --files-without-match '#include[[:space:]]*<linux/export\.h>' |
+	xargs -r printf "%s: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing\n" >&2
+}
+
 check_tracked_ignored_files
+check_missing_include_linux_export_h
-- 
cgit v1.2.3


From 7d95680d64ac8e836c35fd56efe77eac4e9cc26b Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sun, 1 Jun 2025 22:31:30 +0900
Subject: scripts/misc-check: check unnecessary #include <linux/export.h> when
 W=1

Another issue with <linux/export.h> is that it is sometimes included
even when EXPORT_SYMBOL() is not used at all.

Some headers (e.g. include/linux/linkage.h>) cannot be fixed for now
for the reason described in the previous commit.

This commit adds a warning for *.c files that include <linux/export.h>
but do not use EXPORT_SYMBOL() when the kernel is built with W=1.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/misc-check | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'scripts')

diff --git a/scripts/misc-check b/scripts/misc-check
index 7cb61841a125..a74450e799d1 100755
--- a/scripts/misc-check
+++ b/scripts/misc-check
@@ -51,5 +51,17 @@ check_missing_include_linux_export_h () {
 	xargs -r printf "%s: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing\n" >&2
 }
 
+# If you do not use EXPORT_SYMBOL(), please do not include <linux/export.h>.
+# Currently, this is checked for *.c files, but not for *.h files, because some
+# *.c files rely on <linux/export.h> being included indirectly.
+check_unnecessary_include_linux_export_h () {
+
+	git -C "${srctree:-.}" grep --files-with-matches '#include[[:space:]]*<linux/export\.h>' \
+	    -- '*.[c]' :^tools/ |
+	xargs -r git -C "${srctree:-.}" grep --files-without-match -E 'EXPORT_SYMBOL((_NS)?(_GPL)?|_GPL_FOR_MODULES)\(.*\)' |
+	xargs -r printf "%s: warning: EXPORT_SYMBOL() is not used, but #include <linux/export.h> is present\n" >&2
+}
+
 check_tracked_ignored_files
 check_missing_include_linux_export_h
+check_unnecessary_include_linux_export_h
-- 
cgit v1.2.3


From c50a04f8f45c7f13972f9097622d1d929033ea8c Mon Sep 17 00:00:00 2001
From: Petr Pavlu <petr.pavlu@suse.com>
Date: Tue, 3 Jun 2025 15:02:09 +0200
Subject: genksyms: Fix enum consts from a reference affecting new values

Enumeration constants read from a symbol reference file can incorrectly
affect new enumeration constants parsed from an actual input file.

Example:

 $ cat test.c
 enum { E_A, E_B, E_MAX };
 struct bar { int mem[E_MAX]; };
 int foo(struct bar *a) {}
 __GENKSYMS_EXPORT_SYMBOL(foo);

 $ cat test.c | ./scripts/genksyms/genksyms -T test.0.symtypes
 #SYMVER foo 0x070d854d

 $ cat test.0.symtypes
 E#E_MAX 2
 s#bar struct bar { int mem [ E#E_MAX ] ; }
 foo int foo ( s#bar * )

 $ cat test.c | ./scripts/genksyms/genksyms -T test.1.symtypes -r test.0.symtypes
 <stdin>:4: warning: foo: modversion changed because of changes in enum constant E_MAX
 #SYMVER foo 0x9c9dfd81

 $ cat test.1.symtypes
 E#E_MAX ( 2 ) + 3
 s#bar struct bar { int mem [ E#E_MAX ] ; }
 foo int foo ( s#bar * )

The __add_symbol() function includes logic to handle the incrementation of
enumeration values, but this code is also invoked when reading a reference
file. As a result, the variables last_enum_expr and enum_counter might be
incorrectly set after reading the reference file, which later affects
parsing of the actual input.

Fix the problem by splitting the logic for the incrementation of
enumeration values into a separate function process_enum() and call it from
__add_symbol() only when processing non-reference data.

Fixes: e37ddb825003 ("genksyms: Track changes to enum constants")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/genksyms/genksyms.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

(limited to 'scripts')

diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c
index 8b0d7ac73dbb..83e48670c2fc 100644
--- a/scripts/genksyms/genksyms.c
+++ b/scripts/genksyms/genksyms.c
@@ -181,13 +181,9 @@ static int is_unknown_symbol(struct symbol *sym)
 			strcmp(defn->string, "{") == 0);
 }
 
-static struct symbol *__add_symbol(const char *name, enum symbol_type type,
-			    struct string_list *defn, int is_extern,
-			    int is_reference)
+static struct string_list *process_enum(const char *name, enum symbol_type type,
+					struct string_list *defn)
 {
-	unsigned long h;
-	struct symbol *sym;
-	enum symbol_status status = STATUS_UNCHANGED;
 	/* 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.
@@ -216,7 +212,7 @@ static struct symbol *__add_symbol(const char *name, enum symbol_type type,
 				defn = mk_node(buf);
 			}
 		}
-	} else if (type == SYM_ENUM) {
+	} else {
 		free_list(last_enum_expr, NULL);
 		last_enum_expr = NULL;
 		enum_counter = 0;
@@ -225,6 +221,23 @@ static struct symbol *__add_symbol(const char *name, enum symbol_type type,
 			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) ||
-- 
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