Applied.

On 2021/3/4 10:21, Zhichang Yuan wrote:

From: Alexey Gladkov gladkov.alexey@gmail.com

From: Alexey Gladkov gladkov.alexey@gmail.com

mainline inclusion from mainline-v5.2-rc1 commit 898490c010b5d2e499e03b7e815fc214209ac583 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I390TB CVE: NA

Backporting this patch is to fix an issue happened when the 5.10 kernel is building on openEuler 20.03 system.

In openEuler 20.03 system, some modules ware built-in kernel. But in 5.10 kernel, those corresponding modules will be built as KO. For built-in kernel, kmode 2.7+ will fetch the modinfo from modules.builtin.modinfo which is only supported in kernel 5.2+.

In the rpmbuild process, kernel spec will call kmod to query modinfo of the KO images. It will fail for 'file missing'.

With backporting the mainline commit below, kmod can fetch any module's information from the corresponding module image or modules.builtin.modinfo.

---

commit 898490c010b5d2e499e03b7e815fc214209ac583 upstream.

Problem:

When a kernel module is compiled as a separate module, some important information about the kernel module is available via .modinfo section of the module. In contrast, when the kernel module is compiled into the kernel, that information is not available.

Information about built-in modules is necessary in the following cases:

1. When it is necessary to find out what additional parameters can be

passed to the kernel at boot time.

2. When you need to know which module names and their aliases are in

the kernel. This is very useful for creating an initrd image.

Proposal:

The proposed patch does not remove .modinfo section with module information from the vmlinux at the build time and saves it into a separate file after kernel linking. So, the kernel does not increase in size and no additional information remains in it. Information is stored in the same format as in the separate modules (null-terminated string array). Because the .modinfo section is already exported with a separate modules, we are not creating a new API.

It can be easily read in the userspace:

$ tr '\0' '\n' < modules.builtin.modinfo ext4.softdep=pre: crc32c ext4.license=GPL ext4.description=Fourth Extended Filesystem ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others ext4.alias=fs-ext4 ext4.alias=ext3 ext4.alias=fs-ext3 ext4.alias=ext2 ext4.alias=fs-ext2 md_mod.alias=block-major-9-* md_mod.alias=md md_mod.description=MD RAID framework md_mod.license=GPL md_mod.parmtype=create_on_open:bool md_mod.parmtype=start_dirty_degraded:int ...

Co-Developed-by: Gleb Fotengauer-Malinovskiy glebfm@altlinux.org Signed-off-by: Gleb Fotengauer-Malinovskiy glebfm@altlinux.org Signed-off-by: Alexey Gladkov gladkov.alexey@gmail.com Acked-by: Jessica Yu jeyu@kernel.org Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Signed-off-by: Zhichang Yuan erik.yuan@arm.com

---

.gitignore | 1 + Documentation/dontdiff | 1 + Documentation/kbuild/kbuild.txt | 5 +++++ Makefile | 2 ++ include/asm-generic/vmlinux.lds.h | 1 + include/linux/module.h | 1 + include/linux/moduleparam.h | 12 +++++------- scripts/link-vmlinux.sh | 3 +++ 8 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/.gitignore b/.gitignore index 97ba6b79834c..e18bc625d330 100644 --- a/.gitignore +++ b/.gitignore @@ -57,6 +57,7 @@ modules.builtin /vmlinuz /System.map /Module.markers +/modules.builtin.modinfo

# # RPM spec file (make rpm-pkg) diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 2228fcc8e29f..3d4d5a402b8b 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -179,6 +179,7 @@ mktables mktree modpost modules.builtin +modules.builtin.modinfo modules.order modversions.h* nconf diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt index 8390c360d4b3..7f48e48f3fd2 100644 --- a/Documentation/kbuild/kbuild.txt +++ b/Documentation/kbuild/kbuild.txt @@ -11,6 +11,11 @@ modules.builtin This file lists all modules that are built into the kernel. This is used by modprobe to not fail when trying to load something builtin.

+modules.builtin.modinfo +-------------------------------------------------- +This file contains modinfo from all modules that are built into the kernel. +Unlike modinfo of a separate module, all fields are prefixed with module name.

• Environment variables

diff --git a/Makefile b/Makefile index 8f326d0652a7..f19982d051d0 100644 --- a/Makefile +++ b/Makefile @@ -1294,6 +1294,7 @@ _modinst_: fi @cp -f $(objtree)/modules.order $(MODLIB)/ @cp -f $(objtree)/modules.builtin $(MODLIB)/

•   @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
     $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
  
  

  # This depmod is only for convenience to give the initial

@@ -1334,6 +1335,7 @@ endif # CONFIG_MODULES

# Directories & files removed with 'make clean' CLEAN_DIRS += $(MODVERDIR) include/ksym +CLEAN_FILES += modules.builtin.modinfo

# Directories & files removed with 'make mrproper' MRPROPER_DIRS += include/config usr/include include/generated \ diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index f65a924a75ab..701a1af4aa77 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -850,6 +850,7 @@ EXIT_CALL \ *(.discard) \ *(.discard.*) \

•   *(.modinfo)                                                     \
     }
  
  

  /**

diff --git a/include/linux/module.h b/include/linux/module.h index 49942432f010..5056a346f69e 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -239,6 +239,7 @@ extern typeof(name) __mod_##type##__##name##_device_table \ #define MODULE_VERSION(_version) MODULE_INFO(version, _version) #else #define MODULE_VERSION(_version) \

•   MODULE_INFO(version, _version);                                 \
     static struct module_version_attribute ___modver_attr = {       \
             .mattr  = {                                             \
                     .attr   = {                                     \
  

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index ba36506db4fb..5ba250d9172a 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -10,23 +10,21 @@ module name. */ #ifdef MODULE #define MODULE_PARAM_PREFIX /* empty */ +#define __MODULE_INFO_PREFIX /* empty */ #else #define MODULE_PARAM_PREFIX KBUILD_MODNAME "." +/* We cannot use MODULE_PARAM_PREFIX because some modules override it. */ +#define __MODULE_INFO_PREFIX KBUILD_MODNAME "." #endif

/* Chosen so that structs with an unsigned long line up. */ #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))

-#ifdef MODULE #define __MODULE_INFO(tag, name, info) \ static const char __UNIQUE_ID(name)[] \ __used __attribute__((section(".modinfo"), unused, aligned(1))) \

• = __stringify(tag) "=" info

-#else /* !MODULE */ -/* This struct is here for syntactic coherency, it is not used */ -#define __MODULE_INFO(tag, name, info) \

• struct __UNIQUE_ID(name) {}

-#endif

• = __MODULE_INFO_PREFIX __stringify(tag) "=" info
• #define __MODULE_PARM_TYPE(name, _type) \ __MODULE_INFO(parmtype, name##type, #name ":" _type)

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index c8cf45362bd6..c09e87e9c2b9 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -226,6 +226,9 @@ modpost_link vmlinux.o # modpost vmlinux.o to check for section mismatches ${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o

+info MODINFO modules.builtin.modinfo +${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo

• kallsymso="" kallsyms_vmlinux="" if [ -n "${CONFIG_KALLSYMS}" ]; then

-- 2.23.0

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