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| author | Alexey Gladkov <gladkov.alexey@gmail.com> | 2019-04-29 18:11:14 +0200 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2019-05-07 14:50:24 +0200 |
| commit | 898490c010b5d2e499e03b7e815fc214209ac583 (patch) | |
| tree | fcd97072081ce9db13a84bb6463e55923479a171 /Documentation/kbuild | |
| parent | Remove MODULE_ALIAS() calls that take undefined macro (diff) | |
| download | linux-898490c010b5d2e499e03b7e815fc214209ac583.tar.xz linux-898490c010b5d2e499e03b7e815fc214209ac583.zip | |
moduleparam: Save information about built-in modules in separate file
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>
Diffstat (limited to 'Documentation/kbuild')
| -rw-r--r-- | Documentation/kbuild/kbuild.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt index 8a3830b39c7d..9c230ea71963 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 |