[PATCH v7 0/8] Add generated modalias to modules.builtin.modinfo

[PATCH v7 0/8] Add generated modalias to modules.builtin.modinfo

[Alexey Gladkov]

The modules.builtin.modinfo file is used by userspace (kmod to be specific) to
get information about builtin modules. Among other information about the module,
information about module aliases is stored. This is very important to determine
that a particular modalias will be handled by a module that is inside the
kernel.

There are several mechanisms for creating modalias for modules:

The first is to explicitly specify the MODULE_ALIAS of the macro. In this case,
the aliases go into the '.modinfo' section of the module if it is compiled
separately or into vmlinux.o if it is builtin into the kernel.

The second is the use of MODULE_DEVICE_TABLE followed by the use of the
modpost utility. In this case, vmlinux.o no longer has this information and
does not get it into modules.builtin.modinfo.

For example:

$ modinfo pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30
modinfo: ERROR: Module pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30 not found.

$ modinfo xhci_pci
name:           xhci_pci
filename:       (builtin)
license:        GPL
file:           drivers/usb/host/xhci-pci
description:    xHCI PCI Host Controller Driver

The builtin module is missing alias "pci:v*d*sv*sd*bc0Csc03i30*" which will be
generated by modpost if the module is built separately.

To fix this it is necessary to add the generated by modpost modalias to
modules.builtin.modinfo. Fortunately modpost already generates .vmlinux.export.c
for exported symbols. It is possible to add `.modinfo` for builtin modules and
modify the build system so that `.modinfo` section is extracted from the
intermediate vmlinux after modpost is executed.

---
Notes:
- v7:
  * Reorder patches to avoid unnecessary linker warnings on s390.
  * Drop the patch for pinctrl since it's already been applied.
  * v6: https://lore.kernel.org/all/cover.1755170493.git.legion@kernel.org/

- v6:
  * Rebase to v6.17-rc1-16-g8742b2d8935f to pick up the fixes made by Masahiro Yamada.
  * Fix an issue on i386 configs caused by the use of string_32.h.
  * v5: https://lore.kernel.org/all/cover.1753354215.git.legion@kernel.org/

- v5:
  * Rebase to v6.16-rc6-281-gf4a40a4282f4 to pick up the fixes made by Masahiro Yamada.
  * Attempt to fix linker warning on s390.
  * Fix typo in pinctrl/meson found by the kernel test robot.
  * v4: https://lore.kernel.org/all/cover.1750511018.git.legion@kernel.org/

- v4:
  * Rework the patchset based on top of Masahiro Yamada's patches.
  * Add removal of unnecessary __mod_device_table__* symbols to avoid symbol
    table growth in vmlinux.
  * rust code takes into account changes in __mod_device_table__*.
  * v3: https://lore.kernel.org/all/cover.1748335606.git.legion@kernel.org/

- v3:
  * Add `Reviewed-by` tag to patches from Petr Pavlu.
  * Rebase to v6.15.
  * v2: https://lore.kernel.org/all/20250509164237.2886508-1-legion@kernel.org/

- v2:
  * Drop patch for mfd because it was already applied and is in linux-next.
  * The generation of aliases for builtin modules has been redone as
    suggested by Masahiro Yamada.
  * Rebase to v6.15-rc5-136-g9c69f8884904
  * v1: https://lore.kernel.org/all/cover.1745591072.git.legion@kernel.org/


Alexey Gladkov (5):
  s390: vmlinux.lds.S: Reorder sections
  scsi: Always define blogic_pci_tbl structure
  modpost: Add modname to mod_device_table alias
  modpost: Create modalias for builtin modules
  kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o

Masahiro Yamada (3):
  kbuild: always create intermediate vmlinux.unstripped
  kbuild: keep .modinfo section in vmlinux.unstripped
  kbuild: extract modules.builtin.modinfo from vmlinux.unstripped

 arch/s390/kernel/vmlinux.lds.S    | 10 ++--
 drivers/scsi/BusLogic.c           |  4 +-
 include/asm-generic/vmlinux.lds.h |  2 +-
 include/linux/module.h            | 18 ++++++--
 rust/kernel/device_id.rs          |  8 ++--
 scripts/Makefile.vmlinux          | 77 ++++++++++++++++++++-----------
 scripts/Makefile.vmlinux_o        | 26 +----------
 scripts/link-vmlinux.sh           |  5 +-
 scripts/mksysmap                  |  6 +++
 scripts/mod/file2alias.c          | 34 ++++++++++++--
 scripts/mod/modpost.c             | 15 ++++++
 scripts/mod/modpost.h             |  2 +
 12 files changed, 129 insertions(+), 78 deletions(-)

-- 
2.50.1

[PATCH v7 1/8] s390: vmlinux.lds.S: Reorder sections

[Alexey Gladkov]

In the upcoming changes, the ELF_DETAILS macro will be extended with
the ".modinfo" section, which will cause an error:

>> s390x-linux-ld: .tmp_vmlinux1: warning: allocated section `.modinfo' not in segment
>> s390x-linux-ld: .tmp_vmlinux2: warning: allocated section `.modinfo' not in segment
>> s390x-linux-ld: vmlinux.unstripped: warning: allocated section `.modinfo' not in segment

This happens because the .vmlinux.info use :NONE to override the default
segment and tell the linker to not put the section in any segment at all.

To avoid this, we need to change the sections order that will be placed
in the default segment.

Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506062053.zbkFBEnJ-lkp@intel.com/
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
---
 arch/s390/kernel/vmlinux.lds.S | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 1c606dfa595d8..feecf1a6ddb44 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -209,6 +209,11 @@ SECTIONS
 	. = ALIGN(PAGE_SIZE);
 	_end = . ;
 
+	/* Debugging sections.	*/
+	STABS_DEBUG
+	DWARF_DEBUG
+	ELF_DETAILS
+
 	/*
 	 * uncompressed image info used by the decompressor
 	 * it should match struct vmlinux_info
@@ -239,11 +244,6 @@ SECTIONS
 #endif
 	} :NONE
 
-	/* Debugging sections.	*/
-	STABS_DEBUG
-	DWARF_DEBUG
-	ELF_DETAILS
-
 	/*
 	 * Make sure that the .got.plt is either completely empty or it
 	 * contains only the three reserved double words.
-- 
2.50.1

[PATCH v7 2/8] kbuild: always create intermediate vmlinux.unstripped

[Alexey Gladkov]

From: Masahiro Yamada <masahiroy@kernel.org>

Generate the intermediate vmlinux.unstripped regardless of
CONFIG_ARCH_VMLINUX_NEEDS_RELOCS.

If CONFIG_ARCH_VMLINUX_NEEDS_RELOCS is unset, vmlinux.unstripped and
vmlinux are identiacal.

This simplifies the build rule, and allows to strip more sections
by adding them to remove-section-y.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/Makefile.vmlinux | 45 ++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index b64862dc6f08d..4f2d4c3fb7372 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -9,20 +9,6 @@ include $(srctree)/scripts/Makefile.lib
 
 targets :=
 
-ifdef CONFIG_ARCH_VMLINUX_NEEDS_RELOCS
-vmlinux-final := vmlinux.unstripped
-
-quiet_cmd_strip_relocs = RSTRIP  $@
-      cmd_strip_relocs = $(OBJCOPY) --remove-section='.rel*' --remove-section=!'.rel*.dyn' $< $@
-
-vmlinux: $(vmlinux-final) FORCE
-	$(call if_changed,strip_relocs)
-
-targets += vmlinux
-else
-vmlinux-final := vmlinux
-endif
-
 %.o: %.c FORCE
 	$(call if_changed_rule,cc_o_c)
 
@@ -61,19 +47,19 @@ targets += .builtin-dtbs-list
 
 ifdef CONFIG_GENERIC_BUILTIN_DTB
 targets += .builtin-dtbs.S .builtin-dtbs.o
-$(vmlinux-final): .builtin-dtbs.o
+vmlinux.unstripped: .builtin-dtbs.o
 endif
 
-# vmlinux
+# vmlinux.unstripped
 # ---------------------------------------------------------------------------
 
 ifdef CONFIG_MODULES
 targets += .vmlinux.export.o
-$(vmlinux-final): .vmlinux.export.o
+vmlinux.unstripped: .vmlinux.export.o
 endif
 
 ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX
-$(vmlinux-final): arch/$(SRCARCH)/tools/vmlinux.arch.o
+vmlinux.unstripped: arch/$(SRCARCH)/tools/vmlinux.arch.o
 
 arch/$(SRCARCH)/tools/vmlinux.arch.o: vmlinux.o FORCE
 	$(Q)$(MAKE) $(build)=arch/$(SRCARCH)/tools $@
@@ -86,17 +72,30 @@ cmd_link_vmlinux =							\
 	$< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@";	\
 	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
 
-targets += $(vmlinux-final)
-$(vmlinux-final): scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE
+targets += vmlinux.unstripped
+vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE
 	+$(call if_changed_dep,link_vmlinux)
 ifdef CONFIG_DEBUG_INFO_BTF
-$(vmlinux-final): $(RESOLVE_BTFIDS)
+vmlinux.unstripped: $(RESOLVE_BTFIDS)
 endif
 
 ifdef CONFIG_BUILDTIME_TABLE_SORT
-$(vmlinux-final): scripts/sorttable
+vmlinux.unstripped: scripts/sorttable
 endif
 
+# vmlinux
+# ---------------------------------------------------------------------------
+
+remove-section-y                                   :=
+remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*'
+
+quiet_cmd_strip_relocs = OBJCOPY $@
+      cmd_strip_relocs = $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $< $@
+
+targets += vmlinux
+vmlinux: vmlinux.unstripped FORCE
+	$(call if_changed,strip_relocs)
+
 # modules.builtin.ranges
 # ---------------------------------------------------------------------------
 ifdef CONFIG_BUILTIN_MODULE_RANGES
@@ -110,7 +109,7 @@ modules.builtin.ranges: $(srctree)/scripts/generate_builtin_ranges.awk \
 			modules.builtin vmlinux.map vmlinux.o.map FORCE
 	$(call if_changed,modules_builtin_ranges)
 
-vmlinux.map: $(vmlinux-final)
+vmlinux.map: vmlinux.unstripped
 	@:
 
 endif
-- 
2.50.1

[PATCH v7 3/8] kbuild: keep .modinfo section in vmlinux.unstripped

[Alexey Gladkov]

From: Masahiro Yamada <masahiroy@kernel.org>

Keep the .modinfo section during linking, but strip it from the final
vmlinux.

Adjust scripts/mksysmap to exclude modinfo symbols from kallsyms.

This change will allow the next commit to extract the .modinfo section
from the vmlinux.unstripped intermediate.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 include/asm-generic/vmlinux.lds.h | 2 +-
 scripts/Makefile.vmlinux          | 2 +-
 scripts/mksysmap                  | 3 +++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index ae2d2359b79e9..cfa63860dfd4c 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -831,6 +831,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
 
 /* Required sections not related to debugging. */
 #define ELF_DETAILS							\
+		.modinfo : { *(.modinfo) }				\
 		.comment 0 : { *(.comment) }				\
 		.symtab 0 : { *(.symtab) }				\
 		.strtab 0 : { *(.strtab) }				\
@@ -1044,7 +1045,6 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
 	*(.discard.*)							\
 	*(.export_symbol)						\
 	*(.no_trim_symbol)						\
-	*(.modinfo)							\
 	/* ld.bfd warns about .gnu.version* even when not emitted */	\
 	*(.gnu.version*)						\
 
diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index 4f2d4c3fb7372..e2ceeb9e168d4 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -86,7 +86,7 @@ endif
 # vmlinux
 # ---------------------------------------------------------------------------
 
-remove-section-y                                   :=
+remove-section-y                                   := .modinfo
 remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*'
 
 quiet_cmd_strip_relocs = OBJCOPY $@
diff --git a/scripts/mksysmap b/scripts/mksysmap
index 3accbdb269ac7..a607a0059d119 100755
--- a/scripts/mksysmap
+++ b/scripts/mksysmap
@@ -79,6 +79,9 @@
 / _SDA_BASE_$/d
 / _SDA2_BASE_$/d
 
+# MODULE_INFO()
+/ __UNIQUE_ID_modinfo[0-9]*$/d
+
 # ---------------------------------------------------------------------------
 # Ignored patterns
 #  (symbols that contain the pattern are ignored)
-- 
2.50.1

[PATCH v7 4/8] kbuild: extract modules.builtin.modinfo from vmlinux.unstripped

[Alexey Gladkov]

From: Masahiro Yamada <masahiroy@kernel.org>

Currently, we assume all the data for modules.builtin.modinfo are
available in vmlinux.o.

This makes it impossible for modpost, which is invoked after vmlinux.o,
to add additional module info.

This commit moves the modules.builtin.modinfo rule after modpost.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
---
 scripts/Makefile.vmlinux   | 26 ++++++++++++++++++++++++++
 scripts/Makefile.vmlinux_o | 26 +-------------------------
 2 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index e2ceeb9e168d4..fdab5aa90215b 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -96,6 +96,32 @@ targets += vmlinux
 vmlinux: vmlinux.unstripped FORCE
 	$(call if_changed,strip_relocs)
 
+# modules.builtin.modinfo
+# ---------------------------------------------------------------------------
+
+OBJCOPYFLAGS_modules.builtin.modinfo := -j .modinfo -O binary
+
+targets += modules.builtin.modinfo
+modules.builtin.modinfo: vmlinux.unstripped FORCE
+	$(call if_changed,objcopy)
+
+# modules.builtin
+# ---------------------------------------------------------------------------
+
+__default: modules.builtin
+
+# The second line aids cases where multiple modules share the same object.
+
+quiet_cmd_modules_builtin = GEN     $@
+      cmd_modules_builtin = \
+	tr '\0' '\n' < $< | \
+	sed -n 's/^[[:alnum:]:_]*\.file=//p' | \
+	tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$$/.ko/' > $@
+
+targets += modules.builtin
+modules.builtin: modules.builtin.modinfo FORCE
+	$(call if_changed,modules_builtin)
+
 # modules.builtin.ranges
 # ---------------------------------------------------------------------------
 ifdef CONFIG_BUILTIN_MODULE_RANGES
diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
index b024ffb3e2018..23c8751285d79 100644
--- a/scripts/Makefile.vmlinux_o
+++ b/scripts/Makefile.vmlinux_o
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 PHONY := __default
-__default: vmlinux.o modules.builtin.modinfo modules.builtin
+__default: vmlinux.o
 
 include include/config/auto.conf
 include $(srctree)/scripts/Kbuild.include
@@ -73,30 +73,6 @@ vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
 
 targets += vmlinux.o
 
-# modules.builtin.modinfo
-# ---------------------------------------------------------------------------
-
-OBJCOPYFLAGS_modules.builtin.modinfo := -j .modinfo -O binary
-
-targets += modules.builtin.modinfo
-modules.builtin.modinfo: vmlinux.o FORCE
-	$(call if_changed,objcopy)
-
-# modules.builtin
-# ---------------------------------------------------------------------------
-
-# The second line aids cases where multiple modules share the same object.
-
-quiet_cmd_modules_builtin = GEN     $@
-      cmd_modules_builtin = \
-	tr '\0' '\n' < $< | \
-	sed -n 's/^[[:alnum:]:_]*\.file=//p' | \
-	tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$$/.ko/' > $@
-
-targets += modules.builtin
-modules.builtin: modules.builtin.modinfo FORCE
-	$(call if_changed,modules_builtin)
-
 # Add FORCE to the prerequisites of a target to force it to be always rebuilt.
 # ---------------------------------------------------------------------------
 
-- 
2.50.1

[PATCH v7 5/8] scsi: Always define blogic_pci_tbl structure

[Alexey Gladkov]

The blogic_pci_tbl structure is used by the MODULE_DEVICE_TABLE macro.
There is no longer a need to protect it with the MODULE condition, since
this no longer causes the compiler to warn about an unused variable.

To avoid warnings when -Wunused-const-variable option is used, mark it
as __maybe_unused for such configuration.

Cc: Khalid Aziz <khalid@gonehiking.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
---
 drivers/scsi/BusLogic.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
index 1f100270cd385..82597bd96525b 100644
--- a/drivers/scsi/BusLogic.c
+++ b/drivers/scsi/BusLogic.c
@@ -3715,7 +3715,6 @@ static void __exit blogic_exit(void)
 
 __setup("BusLogic=", blogic_setup);
 
-#ifdef MODULE
 /*static const struct pci_device_id blogic_pci_tbl[] = {
 	{ PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_MULTIMASTER,
 	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
@@ -3725,13 +3724,12 @@ __setup("BusLogic=", blogic_setup);
 	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
 	{ }
 };*/
-static const struct pci_device_id blogic_pci_tbl[] = {
+static const struct pci_device_id blogic_pci_tbl[] __maybe_unused = {
 	{PCI_DEVICE(PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_MULTIMASTER)},
 	{PCI_DEVICE(PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_MULTIMASTER_NC)},
 	{PCI_DEVICE(PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_FLASHPOINT)},
 	{0, },
 };
-#endif
 MODULE_DEVICE_TABLE(pci, blogic_pci_tbl);
 
 module_init(blogic_init);
-- 
2.50.1

[PATCH v7 6/8] modpost: Add modname to mod_device_table alias

[Alexey Gladkov]

At this point, if a symbol is compiled as part of the kernel,
information about which module the symbol belongs to is lost.

To save this it is possible to add the module name to the alias name.
It's not very pretty, but it's possible for now.

Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: rust-for-linux@vger.kernel.org
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
---
 include/linux/module.h   | 14 +++++++++++++-
 rust/kernel/device_id.rs |  8 ++++----
 scripts/mod/file2alias.c | 18 ++++++++++++++----
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 3319a5269d286..e31ee29fac6b7 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -244,10 +244,22 @@ struct module_kobject *lookup_or_create_module_kobject(const char *name);
 /* What your module does. */
 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
 
+/*
+ * Format: __mod_device_table__kmod_<modname>__<type>__<name>
+ * Parts of the string `__kmod_` and `__` are used as delimiters when parsing
+ * a symbol in file2alias.c
+ */
+#define __mod_device_table(type, name)	\
+	__PASTE(__mod_device_table__,	\
+	__PASTE(__KBUILD_MODNAME,	\
+	__PASTE(__,			\
+	__PASTE(type,			\
+	__PASTE(__, name)))))
+
 #ifdef MODULE
 /* Creates an alias so file2alias.c can find device table. */
 #define MODULE_DEVICE_TABLE(type, name)					\
-static typeof(name) __mod_device_table__##type##__##name		\
+static typeof(name) __mod_device_table(type, name)			\
   __attribute__ ((used, alias(__stringify(name))))
 #else  /* !MODULE */
 #define MODULE_DEVICE_TABLE(type, name)
diff --git a/rust/kernel/device_id.rs b/rust/kernel/device_id.rs
index 70d57814ff79b..62c42da12e9de 100644
--- a/rust/kernel/device_id.rs
+++ b/rust/kernel/device_id.rs
@@ -195,10 +195,10 @@ macro_rules! module_device_table {
     ($table_type: literal, $module_table_name:ident, $table_name:ident) => {
         #[rustfmt::skip]
         #[export_name =
-            concat!("__mod_device_table__", $table_type,
-                    "__", module_path!(),
-                    "_", line!(),
-                    "_", stringify!($table_name))
+            concat!("__mod_device_table__", line!(),
+                    "__kmod_", module_path!(),
+                    "__", $table_type,
+                    "__", stringify!($table_name))
         ]
         static $module_table_name: [::core::mem::MaybeUninit<u8>; $table_name.raw_ids().size()] =
             unsafe { ::core::mem::transmute_copy($table_name.raw_ids()) };
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 00586119a25b7..13021266a18f8 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -1476,8 +1476,8 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
 {
 	void *symval;
 	char *zeros = NULL;
-	const char *type, *name;
-	size_t typelen;
+	const char *type, *name, *modname;
+	size_t typelen, modnamelen;
 	static const char *prefix = "__mod_device_table__";
 
 	/* We're looking for a section relative symbol */
@@ -1488,10 +1488,20 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
 	if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
 		return;
 
-	/* All our symbols are of form __mod_device_table__<type>__<name>. */
+	/* All our symbols are of form __mod_device_table__kmod_<modname>__<type>__<name>. */
 	if (!strstarts(symname, prefix))
 		return;
-	type = symname + strlen(prefix);
+
+	modname = strstr(symname, "__kmod_");
+	if (!modname)
+		return;
+	modname += strlen("__kmod_");
+
+	type = strstr(modname, "__");
+	if (!type)
+		return;
+	modnamelen = type - modname;
+	type += strlen("__");
 
 	name = strstr(type, "__");
 	if (!name)
-- 
2.50.1

[PATCH v7 7/8] modpost: Create modalias for builtin modules

[Alexey Gladkov]

For some modules, modalias is generated using the modpost utility and
the section is added to the module file.

When a module is added inside vmlinux, modpost does not generate
modalias for such modules and the information is lost.

As a result kmod (which uses modules.builtin.modinfo in userspace)
cannot determine that modalias is handled by a builtin kernel module.

$ cat /sys/devices/pci0000:00/0000:00:14.0/modalias
pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30

$ modinfo xhci_pci
name:           xhci_pci
filename:       (builtin)
license:        GPL
file:           drivers/usb/host/xhci-pci
description:    xHCI PCI Host Controller Driver

Missing modalias "pci:v*d*sv*sd*bc0Csc03i30*" which will be generated by
modpost if the module is built separately.

To fix this it is necessary to generate the same modalias for vmlinux as
for the individual modules. Fortunately '.vmlinux.export.o' is already
generated from which '.modinfo' can be extracted in the same way as for
vmlinux.o.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 include/linux/module.h   |  4 ----
 scripts/Makefile.vmlinux |  5 ++++-
 scripts/mksysmap         |  3 +++
 scripts/mod/file2alias.c | 16 ++++++++++++++++
 scripts/mod/modpost.c    | 15 +++++++++++++++
 scripts/mod/modpost.h    |  2 ++
 6 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index e31ee29fac6b7..e135cc79aceea 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -256,14 +256,10 @@ struct module_kobject *lookup_or_create_module_kobject(const char *name);
 	__PASTE(type,			\
 	__PASTE(__, name)))))
 
-#ifdef MODULE
 /* Creates an alias so file2alias.c can find device table. */
 #define MODULE_DEVICE_TABLE(type, name)					\
 static typeof(name) __mod_device_table(type, name)			\
   __attribute__ ((used, alias(__stringify(name))))
-#else  /* !MODULE */
-#define MODULE_DEVICE_TABLE(type, name)
-#endif
 
 /* Version of form [<epoch>:]<version>[-<extra-version>].
  * Or for CVS/RCS ID version, everything but the number is stripped.
diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index fdab5aa90215b..fcc188d26ead1 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -89,8 +89,11 @@ endif
 remove-section-y                                   := .modinfo
 remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*'
 
+remove-symbols := -w --strip-symbol='__mod_device_table__*'
+
 quiet_cmd_strip_relocs = OBJCOPY $@
-      cmd_strip_relocs = $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $< $@
+      cmd_strip_relocs = $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) \
+                         $(remove-symbols) $< $@
 
 targets += vmlinux
 vmlinux: vmlinux.unstripped FORCE
diff --git a/scripts/mksysmap b/scripts/mksysmap
index a607a0059d119..c4531eacde202 100755
--- a/scripts/mksysmap
+++ b/scripts/mksysmap
@@ -59,6 +59,9 @@
 # EXPORT_SYMBOL (namespace)
 / __kstrtabns_/d
 
+# MODULE_DEVICE_TABLE (symbol name)
+/ __mod_device_table__/d
+
 # ---------------------------------------------------------------------------
 # Ignored suffixes
 #  (do not forget '$' after each pattern)
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 13021266a18f8..7da9735e7ab3e 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -1527,5 +1527,21 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
 		}
 	}
 
+	if (mod->is_vmlinux) {
+		struct module_alias *alias;
+
+		/*
+		 * If this is vmlinux, record the name of the builtin module.
+		 * Traverse the linked list in the reverse order, and set the
+		 * builtin_modname unless it has already been set in the
+		 * previous call.
+		 */
+		list_for_each_entry_reverse(alias, &mod->aliases, node) {
+			if (alias->builtin_modname)
+				break;
+			alias->builtin_modname = xstrndup(modname, modnamelen);
+		}
+	}
+
 	free(zeros);
 }
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 5ca7c268294eb..47c8aa2a69392 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2067,11 +2067,26 @@ static void write_if_changed(struct buffer *b, const char *fname)
 static void write_vmlinux_export_c_file(struct module *mod)
 {
 	struct buffer buf = { };
+	struct module_alias *alias, *next;
 
 	buf_printf(&buf,
 		   "#include <linux/export-internal.h>\n");
 
 	add_exported_symbols(&buf, mod);
+
+	buf_printf(&buf,
+		   "#include <linux/module.h>\n"
+		   "#undef __MODULE_INFO_PREFIX\n"
+		   "#define __MODULE_INFO_PREFIX\n");
+
+	list_for_each_entry_safe(alias, next, &mod->aliases, node) {
+		buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n",
+			   alias->builtin_modname, alias->str);
+		list_del(&alias->node);
+		free(alias->builtin_modname);
+		free(alias);
+	}
+
 	write_if_changed(&buf, ".vmlinux.export.c");
 	free(buf.p);
 }
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 9133e4c3803f0..2aecb8f25c87e 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -99,10 +99,12 @@ buf_write(struct buffer *buf, const char *s, int len);
  * struct module_alias - auto-generated MODULE_ALIAS()
  *
  * @node: linked to module::aliases
+ * @modname: name of the builtin module (only for vmlinux)
  * @str: a string for MODULE_ALIAS()
  */
 struct module_alias {
 	struct list_head node;
+	char *builtin_modname;
 	char str[];
 };
 
-- 
2.50.1

[PATCH v7 8/8] kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o

[Alexey Gladkov]

Since .vmlinux.export.c is used to add generated by modpost modaliases
for builtin modules the .vmlinux.export.o is no longer optional and
should always be created. The generation of this file is not dependent
on CONFIG_MODULES.

Signed-off-by: Alexey Gladkov <legion@kernel.org>
---
 scripts/Makefile.vmlinux | 9 ++-------
 scripts/link-vmlinux.sh  | 5 +----
 2 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index fcc188d26ead1..dbbe3bf0cf234 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -53,11 +53,6 @@ endif
 # vmlinux.unstripped
 # ---------------------------------------------------------------------------
 
-ifdef CONFIG_MODULES
-targets += .vmlinux.export.o
-vmlinux.unstripped: .vmlinux.export.o
-endif
-
 ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX
 vmlinux.unstripped: arch/$(SRCARCH)/tools/vmlinux.arch.o
 
@@ -72,8 +67,8 @@ cmd_link_vmlinux =							\
 	$< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@";	\
 	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
 
-targets += vmlinux.unstripped
-vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE
+targets += vmlinux.unstripped .vmlinux.export.o
+vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o .vmlinux.export.o $(KBUILD_LDS) FORCE
 	+$(call if_changed_dep,link_vmlinux)
 ifdef CONFIG_DEBUG_INFO_BTF
 vmlinux.unstripped: $(RESOLVE_BTFIDS)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 51367c2bfc21e..433849ff7529e 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -73,10 +73,7 @@ vmlinux_link()
 		objs="${objs} .builtin-dtbs.o"
 	fi
 
-	if is_enabled CONFIG_MODULES; then
-		objs="${objs} .vmlinux.export.o"
-	fi
-
+	objs="${objs} .vmlinux.export.o"
 	objs="${objs} init/version-timestamp.o"
 
 	if [ "${SRCARCH}" = "um" ]; then
-- 
2.50.1