[PATCH v3 0/8] scalable symbol flags with __kflagstab

[PATCH v3 0/8] scalable symbol flags with __kflagstab

[Siddharth Nayyar]

This patch series implements a mechanism for scalable exported symbol
flags using a separate section called __kflagstab. The series introduces
__kflagstab support, removes *_gpl sections in favor of a GPL flag,
simplifies symbol resolution during module loading.

This series previously added symbol import protection which aims to
restrict the use of "protected symbol" exported by vmlinux, as a use
case for which __kflagstab is being introduced. Such symbols are only
allowed to be imported by signed modules when symbol protection is
enabled. This functionality requires more thought and discussion [1],
and therefore I will create a separate patch series for it. In the
meantime, this series now only focuses on introduction of __kflagstab
which right is an improvement to the module loader's code health [2].

Thank you Petr Pavlu and Jonathan Corbet for their valuable feedback.

---
Changes from v2:
- removed symbol import protection to spin off into its own series

v2:
https://lore.kernel.org/20251013153918.2206045-1-sidnayyar@google.com/

Changes from v1:
- added a check to ensure __kflagstab is present
- added warnings for the obsolete *_gpl sections
- moved protected symbol check before ref_module() call
- moved protected symbol check failure warning to issue detection point

v1:
https://lore.kernel.org/20250829105418.3053274-1-sidnayyar@google.com/

[1] https://lore.kernel.org/cac5ed5e-3320-4db0-99d8-ea5e97e56bfb@suse.com/
[2] https://lore.kernel.org/2bf54830-ea9c-4962-a7ef-653fbed8f8c0@suse.com/

Siddharth Nayyar (8):
  define kernel symbol flags
  linker: add kflagstab section to vmlinux and modules
  modpost: create entries for kflagstab
  module loader: use kflagstab instead of *_gpl sections
  modpost: put all exported symbols in ksymtab section
  module loader: remove references of *_gpl sections
  linker: remove *_gpl sections from vmlinux and modules
  remove references to *_gpl sections in documentation

 Documentation/kbuild/modules.rst  |  11 ++--
 include/asm-generic/vmlinux.lds.h |  21 ++----
 include/linux/export-internal.h   |  28 +++++---
 include/linux/module.h            |   4 +-
 include/linux/module_symbol.h     |   5 ++
 kernel/module/internal.h          |   4 +-
 kernel/module/main.c              | 102 ++++++++++++++----------------
 scripts/mod/modpost.c             |  16 +++--
 scripts/module.lds.S              |   3 +-
 9 files changed, 99 insertions(+), 95 deletions(-)

-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 1/8] define kernel symbol flags

[Siddharth Nayyar]

Symbol flags is an enumeration used to represent flags as a bitset, for
example a flag to tell if a symbols GPL only.

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 include/linux/module_symbol.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/module_symbol.h b/include/linux/module_symbol.h
index 77c9895b9ddb..574609aced99 100644
--- a/include/linux/module_symbol.h
+++ b/include/linux/module_symbol.h
@@ -2,6 +2,11 @@
 #ifndef _LINUX_MODULE_SYMBOL_H
 #define _LINUX_MODULE_SYMBOL_H
 
+/* Kernel symbol flags bitset. */
+enum ksym_flags {
+	KSYM_FLAG_GPL_ONLY	= 1 << 0,
+};
+
 /* This ignores the intensely annoying "mapping symbols" found in ELF files. */
 static inline bool is_mapping_symbol(const char *str)
 {
-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 2/8] linker: add kflagstab section to vmlinux and modules

[Siddharth Nayyar]

This section will contain read-only kernel symbol flag values in the
form of a 8-bit bitset.

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 include/asm-generic/vmlinux.lds.h | 7 +++++++
 scripts/module.lds.S              | 1 +
 2 files changed, 8 insertions(+)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index ae2d2359b79e..310e2de56211 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -518,6 +518,13 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
 		__stop___kcrctab_gpl = .;				\
 	}								\
 									\
+	/* Kernel symbol flags table */					\
+	__kflagstab       : AT(ADDR(__kflagstab) - LOAD_OFFSET) {	\
+		__start___kflagstab = .;				\
+		KEEP(*(SORT(___kflagstab+*)))				\
+		__stop___kflagstab = .;					\
+	}								\
+									\
 	/* Kernel symbol table: strings */				\
         __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) {	\
 		*(__ksymtab_strings)					\
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index ee79c41059f3..9a8a3b6d1569 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -23,6 +23,7 @@ SECTIONS {
 	__ksymtab_gpl		0 : ALIGN(8) { *(SORT(___ksymtab_gpl+*)) }
 	__kcrctab		0 : ALIGN(4) { *(SORT(___kcrctab+*)) }
 	__kcrctab_gpl		0 : ALIGN(4) { *(SORT(___kcrctab_gpl+*)) }
+	__kflagstab		0 : ALIGN(1) { *(SORT(___kflagstab+*)) }
 
 	.ctors			0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) }
 	.init_array		0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 3/8] modpost: create entries for kflagstab

[Siddharth Nayyar]

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 include/linux/export-internal.h | 7 +++++++
 scripts/mod/modpost.c           | 8 ++++++++
 2 files changed, 15 insertions(+)

diff --git a/include/linux/export-internal.h b/include/linux/export-internal.h
index d445705ac13c..4123c7592404 100644
--- a/include/linux/export-internal.h
+++ b/include/linux/export-internal.h
@@ -69,4 +69,11 @@
 	    ".long " #crc					"\n" \
 	    ".previous"						"\n")
 
+#define SYMBOL_FLAGS(sym, flags)					\
+	asm("	.section \"___kflagstab+" #sym "\",\"a\""	"\n"	\
+	    "__flags_" #sym ":"					"\n"	\
+	    "	.byte " #flags					"\n"	\
+	    "	.previous"					"\n"	\
+	)
+
 #endif /* __LINUX_EXPORT_INTERNAL_H__ */
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 5ca7c268294e..f5ce7aeed52d 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -244,6 +244,11 @@ static struct symbol *alloc_symbol(const char *name)
 	return s;
 }
 
+static uint8_t get_symbol_flags(const struct symbol *sym)
+{
+	return sym->is_gpl_only ? KSYM_FLAG_GPL_ONLY : 0;
+}
+
 /* For the hash of exported symbols */
 static void hash_add_symbol(struct symbol *sym)
 {
@@ -1865,6 +1870,9 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod)
 		buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
 			   sym->is_func ? "FUNC" : "DATA", sym->name,
 			   sym->is_gpl_only ? "_gpl" : "", sym->namespace);
+
+		buf_printf(buf, "SYMBOL_FLAGS(%s, 0x%02x);\n",
+			   sym->name, get_symbol_flags(sym));
 	}
 
 	if (!modversions)
-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 4/8] module loader: use kflagstab instead of *_gpl sections

[Siddharth Nayyar]

Read __kflagstab section for vmlinux and modules to determine whether
kernel symbols are GPL only.

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 include/linux/module.h   |  1 +
 kernel/module/internal.h |  1 +
 kernel/module/main.c     | 55 +++++++++++++++++++++-------------------
 3 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 3319a5269d28..9ba6ce433ac3 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -415,6 +415,7 @@ struct module {
 	/* Exported symbols */
 	const struct kernel_symbol *syms;
 	const u32 *crcs;
+	const u8 *flagstab;
 	unsigned int num_syms;
 
 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 618202578b42..69b84510e097 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -57,6 +57,7 @@ extern const struct kernel_symbol __start___ksymtab_gpl[];
 extern const struct kernel_symbol __stop___ksymtab_gpl[];
 extern const u32 __start___kcrctab[];
 extern const u32 __start___kcrctab_gpl[];
+extern const u8 __start___kflagstab[];
 
 #define KMOD_PATH_LEN 256
 extern char modprobe_path[];
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c66b26184936..4197af526087 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -11,6 +11,7 @@
 #include <linux/extable.h>
 #include <linux/moduleloader.h>
 #include <linux/module_signature.h>
+#include <linux/module_symbol.h>
 #include <linux/trace_events.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
@@ -87,7 +88,7 @@ struct mod_tree_root mod_tree __cacheline_aligned = {
 struct symsearch {
 	const struct kernel_symbol *start, *stop;
 	const u32 *crcs;
-	enum mod_license license;
+	const u8 *flagstab;
 };
 
 /*
@@ -364,19 +365,21 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
 					    struct find_symbol_arg *fsa)
 {
 	struct kernel_symbol *sym;
-
-	if (!fsa->gplok && syms->license == GPL_ONLY)
-		return false;
+	u8 sym_flags;
 
 	sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
 			sizeof(struct kernel_symbol), cmp_name);
 	if (!sym)
 		return false;
 
+	sym_flags = *(syms->flagstab + (sym - syms->start));
+	if (!fsa->gplok && (sym_flags & KSYM_FLAG_GPL_ONLY))
+		return false;
+
 	fsa->owner = owner;
 	fsa->crc = symversion(syms->crcs, sym - syms->start);
 	fsa->sym = sym;
-	fsa->license = syms->license;
+	fsa->license = (sym_flags & KSYM_FLAG_GPL_ONLY) ? GPL_ONLY : NOT_GPL_ONLY;
 
 	return true;
 }
@@ -387,36 +390,31 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
  */
 bool find_symbol(struct find_symbol_arg *fsa)
 {
-	static const struct symsearch arr[] = {
-		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
-		  NOT_GPL_ONLY },
-		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
-		  __start___kcrctab_gpl,
-		  GPL_ONLY },
+	const struct symsearch syms = {
+		.start		= __start___ksymtab,
+		.stop		= __stop___ksymtab,
+		.crcs		= __start___kcrctab,
+		.flagstab	= __start___kflagstab,
 	};
 	struct module *mod;
-	unsigned int i;
 
-	for (i = 0; i < ARRAY_SIZE(arr); i++)
-		if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
-			return true;
+	if (find_exported_symbol_in_section(&syms, NULL, fsa))
+		return true;
 
 	list_for_each_entry_rcu(mod, &modules, list,
 				lockdep_is_held(&module_mutex)) {
-		struct symsearch arr[] = {
-			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
-			  NOT_GPL_ONLY },
-			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
-			  mod->gpl_crcs,
-			  GPL_ONLY },
+		const struct symsearch syms = {
+			.start		= mod->syms,
+			.stop		= mod->syms + mod->num_syms,
+			.crcs		= mod->crcs,
+			.flagstab	= mod->flagstab,
 		};
 
 		if (mod->state == MODULE_STATE_UNFORMED)
 			continue;
 
-		for (i = 0; i < ARRAY_SIZE(arr); i++)
-			if (find_exported_symbol_in_section(&arr[i], mod, fsa))
-				return true;
+		if (find_exported_symbol_in_section(&syms, mod, fsa))
+			return true;
 	}
 
 	pr_debug("Failed to find symbol %s\n", fsa->name);
@@ -2607,6 +2605,7 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 				     sizeof(*mod->gpl_syms),
 				     &mod->num_gpl_syms);
 	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
+	mod->flagstab = section_addr(info, "__kflagstab");
 
 #ifdef CONFIG_CONSTRUCTORS
 	mod->ctors = section_objs(info, ".ctors",
@@ -2810,8 +2809,12 @@ static int move_module(struct module *mod, struct load_info *info)
 	return ret;
 }
 
-static int check_export_symbol_versions(struct module *mod)
+static int check_export_symbol_sections(struct module *mod)
 {
+	if (mod->num_syms && !mod->flagstab) {
+		pr_err("%s: no flags for exported symbols\n", mod->name);
+		return -ENOEXEC;
+	}
 #ifdef CONFIG_MODVERSIONS
 	if ((mod->num_syms && !mod->crcs) ||
 	    (mod->num_gpl_syms && !mod->gpl_crcs)) {
@@ -3427,7 +3430,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	if (err)
 		goto free_unload;
 
-	err = check_export_symbol_versions(mod);
+	err = check_export_symbol_sections(mod);
 	if (err)
 		goto free_unload;
 
-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 5/8] modpost: put all exported symbols in ksymtab section

[Siddharth Nayyar]

Since the modules loader determines whether an exported symbol is GPL
only from the kflagstab section data, modpost can put all symbols in the
regular ksymtab and stop using the *_gpl versions of the ksymtab and
kcrctab.

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 include/linux/export-internal.h | 21 +++++++++++----------
 scripts/mod/modpost.c           |  8 ++++----
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/include/linux/export-internal.h b/include/linux/export-internal.h
index 4123c7592404..726054614752 100644
--- a/include/linux/export-internal.h
+++ b/include/linux/export-internal.h
@@ -37,14 +37,14 @@
  * section flag requires it. Use '%progbits' instead of '@progbits' since the
  * former apparently works on all arches according to the binutils source.
  */
-#define __KSYMTAB(name, sym, sec, ns)						\
+#define __KSYMTAB(name, sym, ns)						\
 	asm("	.section \"__ksymtab_strings\",\"aMS\",%progbits,1"	"\n"	\
 	    "__kstrtab_" #name ":"					"\n"	\
 	    "	.asciz \"" #name "\""					"\n"	\
 	    "__kstrtabns_" #name ":"					"\n"	\
 	    "	.asciz \"" ns "\""					"\n"	\
 	    "	.previous"						"\n"	\
-	    "	.section \"___ksymtab" sec "+" #name "\", \"a\""	"\n"	\
+	    "	.section \"___ksymtab+" #name "\", \"a\""		"\n"	\
 		__KSYM_ALIGN						"\n"	\
 	    "__ksymtab_" #name ":"					"\n"	\
 		__KSYM_REF(sym)						"\n"	\
@@ -59,15 +59,16 @@
 #define KSYM_FUNC(name)		name
 #endif
 
-#define KSYMTAB_FUNC(name, sec, ns)	__KSYMTAB(name, KSYM_FUNC(name), sec, ns)
-#define KSYMTAB_DATA(name, sec, ns)	__KSYMTAB(name, name, sec, ns)
+#define KSYMTAB_FUNC(name, ns)	__KSYMTAB(name, KSYM_FUNC(name), ns)
+#define KSYMTAB_DATA(name, ns)	__KSYMTAB(name, name, ns)
 
-#define SYMBOL_CRC(sym, crc, sec)   \
-	asm(".section \"___kcrctab" sec "+" #sym "\",\"a\""	"\n" \
-	    ".balign 4"						"\n" \
-	    "__crc_" #sym ":"					"\n" \
-	    ".long " #crc					"\n" \
-	    ".previous"						"\n")
+#define SYMBOL_CRC(sym, crc)					\
+	asm("	.section \"___kcrctab+" #sym "\",\"a\""	"\n"	\
+	    "	.balign 4"				"\n"	\
+	    "__crc_" #sym ":"				"\n"	\
+	    "	.long " #crc				"\n"	\
+	    "	.previous"				"\n"	\
+	)
 
 #define SYMBOL_FLAGS(sym, flags)					\
 	asm("	.section \"___kflagstab+" #sym "\",\"a\""	"\n"	\
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index f5ce7aeed52d..8936db84779b 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1867,9 +1867,9 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod)
 		if (trim_unused_exports && !sym->used)
 			continue;
 
-		buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
+		buf_printf(buf, "KSYMTAB_%s(%s, \"%s\");\n",
 			   sym->is_func ? "FUNC" : "DATA", sym->name,
-			   sym->is_gpl_only ? "_gpl" : "", sym->namespace);
+			   sym->namespace);
 
 		buf_printf(buf, "SYMBOL_FLAGS(%s, 0x%02x);\n",
 			   sym->name, get_symbol_flags(sym));
@@ -1890,8 +1890,8 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod)
 			     sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
 			     sym->name);
 
-		buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
-			   sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
+		buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x);\n",
+			   sym->name, sym->crc);
 	}
 }
 
-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 6/8] module loader: remove references of *_gpl sections

[Siddharth Nayyar]

The *_gpl section are not being used populated by modpost anymore. Hence
the module loader doesn't need to find and process these sections in
modules.

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 include/linux/module.h   |  3 ---
 kernel/module/internal.h |  3 ---
 kernel/module/main.c     | 47 ++++++++++++++++------------------------
 3 files changed, 19 insertions(+), 34 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 9ba6ce433ac3..1a9c41318e22 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -431,9 +431,6 @@ struct module {
 	unsigned int num_kp;
 
 	/* GPL-only exported symbols. */
-	unsigned int num_gpl_syms;
-	const struct kernel_symbol *gpl_syms;
-	const u32 *gpl_crcs;
 	bool using_gplonly_symbols;
 
 #ifdef CONFIG_MODULE_SIG
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 69b84510e097..061161cc79d9 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -53,10 +53,7 @@ extern const size_t modinfo_attrs_count;
 /* Provided by the linker */
 extern const struct kernel_symbol __start___ksymtab[];
 extern const struct kernel_symbol __stop___ksymtab[];
-extern const struct kernel_symbol __start___ksymtab_gpl[];
-extern const struct kernel_symbol __stop___ksymtab_gpl[];
 extern const u32 __start___kcrctab[];
-extern const u32 __start___kcrctab_gpl[];
 extern const u8 __start___kflagstab[];
 
 #define KMOD_PATH_LEN 256
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 4197af526087..f5f9872dc070 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1464,29 +1464,18 @@ EXPORT_SYMBOL_GPL(__symbol_get);
  */
 static int verify_exported_symbols(struct module *mod)
 {
-	unsigned int i;
 	const struct kernel_symbol *s;
-	struct {
-		const struct kernel_symbol *sym;
-		unsigned int num;
-	} arr[] = {
-		{ mod->syms, mod->num_syms },
-		{ mod->gpl_syms, mod->num_gpl_syms },
-	};
-
-	for (i = 0; i < ARRAY_SIZE(arr); i++) {
-		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
-			struct find_symbol_arg fsa = {
-				.name	= kernel_symbol_name(s),
-				.gplok	= true,
-			};
-			if (find_symbol(&fsa)) {
-				pr_err("%s: exports duplicate symbol %s"
-				       " (owned by %s)\n",
-				       mod->name, kernel_symbol_name(s),
-				       module_name(fsa.owner));
-				return -ENOEXEC;
-			}
+	for (s = mod->syms; s < mod->syms + mod->num_syms; s++) {
+		struct find_symbol_arg fsa = {
+			.name	= kernel_symbol_name(s),
+			.gplok	= true,
+		};
+		if (find_symbol(&fsa)) {
+			pr_err("%s: exports duplicate symbol %s"
+				" (owned by %s)\n",
+				mod->name, kernel_symbol_name(s),
+				module_name(fsa.owner));
+			return -ENOEXEC;
 		}
 	}
 	return 0;
@@ -2601,12 +2590,15 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 	mod->syms = section_objs(info, "__ksymtab",
 				 sizeof(*mod->syms), &mod->num_syms);
 	mod->crcs = section_addr(info, "__kcrctab");
-	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
-				     sizeof(*mod->gpl_syms),
-				     &mod->num_gpl_syms);
-	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
 	mod->flagstab = section_addr(info, "__kflagstab");
 
+	if (section_addr(info, "__ksymtab_gpl"))
+		pr_warn("%s: ignoring obsolete section __ksymtab_gpl\n",
+			mod->name);
+	if (section_addr(info, "__kcrctab_gpl"))
+		pr_warn("%s: ignoring obsolete section __kcrctab_gpl\n",
+			mod->name);
+
 #ifdef CONFIG_CONSTRUCTORS
 	mod->ctors = section_objs(info, ".ctors",
 				  sizeof(*mod->ctors), &mod->num_ctors);
@@ -2816,8 +2808,7 @@ static int check_export_symbol_sections(struct module *mod)
 		return -ENOEXEC;
 	}
 #ifdef CONFIG_MODVERSIONS
-	if ((mod->num_syms && !mod->crcs) ||
-	    (mod->num_gpl_syms && !mod->gpl_crcs)) {
+	if (mod->num_syms && !mod->crcs) {
 		return try_to_force_load(mod,
 					 "no versions for exported symbols");
 	}
-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 7/8] linker: remove *_gpl sections from vmlinux and modules

[Siddharth Nayyar]

These sections are not used anymore and can be removed from vmlinux and
modules.

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 include/asm-generic/vmlinux.lds.h | 18 ++----------------
 scripts/module.lds.S              |  2 --
 2 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 310e2de56211..6490b93d23b1 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -490,34 +490,20 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
 									\
 	PRINTK_INDEX							\
 									\
-	/* Kernel symbol table: Normal symbols */			\
+	/* Kernel symbol table */					\
 	__ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {		\
 		__start___ksymtab = .;					\
 		KEEP(*(SORT(___ksymtab+*)))				\
 		__stop___ksymtab = .;					\
 	}								\
 									\
-	/* Kernel symbol table: GPL-only symbols */			\
-	__ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {	\
-		__start___ksymtab_gpl = .;				\
-		KEEP(*(SORT(___ksymtab_gpl+*)))				\
-		__stop___ksymtab_gpl = .;				\
-	}								\
-									\
-	/* Kernel symbol table: Normal symbols */			\
+	/* Kernel symbol CRC table */					\
 	__kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {		\
 		__start___kcrctab = .;					\
 		KEEP(*(SORT(___kcrctab+*)))				\
 		__stop___kcrctab = .;					\
 	}								\
 									\
-	/* Kernel symbol table: GPL-only symbols */			\
-	__kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {	\
-		__start___kcrctab_gpl = .;				\
-		KEEP(*(SORT(___kcrctab_gpl+*)))				\
-		__stop___kcrctab_gpl = .;				\
-	}								\
-									\
 	/* Kernel symbol flags table */					\
 	__kflagstab       : AT(ADDR(__kflagstab) - LOAD_OFFSET) {	\
 		__start___kflagstab = .;				\
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 9a8a3b6d1569..1841a43d8771 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -20,9 +20,7 @@ SECTIONS {
 	}
 
 	__ksymtab		0 : ALIGN(8) { *(SORT(___ksymtab+*)) }
-	__ksymtab_gpl		0 : ALIGN(8) { *(SORT(___ksymtab_gpl+*)) }
 	__kcrctab		0 : ALIGN(4) { *(SORT(___kcrctab+*)) }
-	__kcrctab_gpl		0 : ALIGN(4) { *(SORT(___kcrctab_gpl+*)) }
 	__kflagstab		0 : ALIGN(1) { *(SORT(___kflagstab+*)) }
 
 	.ctors			0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) }
-- 
2.51.1.930.gacf6e81ea2-goog

[PATCH v3 8/8] remove references to *_gpl sections in documentation

[Siddharth Nayyar]

Signed-off-by: Siddharth Nayyar <sidnayyar@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
 Documentation/kbuild/modules.rst | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst
index d0703605bfa4..b3a26a36ee17 100644
--- a/Documentation/kbuild/modules.rst
+++ b/Documentation/kbuild/modules.rst
@@ -426,11 +426,12 @@ Symbols From the Kernel (vmlinux + modules)
 Version Information Formats
 ---------------------------
 
-	Exported symbols have information stored in __ksymtab or __ksymtab_gpl
-	sections. Symbol names and namespaces are stored in __ksymtab_strings,
-	using a format similar to the string table used for ELF. If
-	CONFIG_MODVERSIONS is enabled, the CRCs corresponding to exported
-	symbols will be added to the __kcrctab or __kcrctab_gpl.
+	Exported symbols have information stored in the __ksymtab and
+	__kflagstab sections. Symbol names and namespaces are stored in
+	__ksymtab_strings section, using a format similar to the string
+	table used for ELF. If CONFIG_MODVERSIONS is enabled, the CRCs
+	corresponding to exported symbols will be added to the
+	__kcrctab section.
 
 	If CONFIG_BASIC_MODVERSIONS is enabled (default with
 	CONFIG_MODVERSIONS), imported symbols will have their symbol name and
-- 
2.51.1.930.gacf6e81ea2-goog