linux/usr
Masahiro Yamada 9371f86ecb bpfilter: match bit size of bpfilter_umh to that of the kernel
bpfilter_umh is built for the default machine bit of the compiler,
which may not match to the bit size of the kernel.

This happens in the scenario below:

You can use biarch GCC that defaults to 64-bit for building the 32-bit
kernel. In this case, Kbuild passes -m32 to teach the compiler to
produce 32-bit kernel space objects. However, it is missing when
building bpfilter_umh. It is built as a 64-bit ELF, and then embedded
into the 32-bit kernel.

The 32-bit kernel and 64-bit umh is a bad combination.

In theory, we can have 32-bit umh running on 64-bit kernel, but we do
not have a good reason to support such a usecase.

The best is to match the bit size between them.

Pass -m32 or -m64 to the umh build command if it is found in
$(KBUILD_CFLAGS). Evaluate CC_CAN_LINK against the kernel bit-size.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-17 18:52:01 +09:00
..
include bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
Kconfig initramfs: restore default compression behavior 2020-03-17 09:50:37 +09:00
Makefile Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
default_cpio_list initramfs: add default_cpio_list, and delete -d option support 2020-01-16 00:25:22 +09:00
gen_init_cpio.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
gen_initramfs.sh gen_initramfs.sh: remove intermediate cpio_list on errors 2020-01-16 00:26:22 +09:00
initramfs_data.S initramfs: refactor the initramfs build rules 2020-01-16 00:26:21 +09:00