kernel_optimize_test/init
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
..
calibrate.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
do_mounts_initrd.c init: unify opening /dev/console as stdin/stdout/stderr 2019-12-12 18:58:24 +01:00
do_mounts_md.c init/: remove ineffective sparse disabling 2018-08-22 10:52:49 -07:00
do_mounts_rd.c init/: remove ineffective sparse disabling 2018-08-22 10:52:49 -07:00
do_mounts.c block: remove __bdevname 2020-03-24 07:57:07 -06:00
do_mounts.h fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls to syscall 2018-04-02 20:15:56 +02:00
init_task.c exec: Add exec_update_mutex to replace cred_guard_mutex 2020-03-25 10:03:36 -05:00
initramfs.c gcc-10: mark more functions __init to avoid section mismatch warnings 2020-05-09 17:50:03 -07:00
Kconfig bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
main.c bootconfig: Fix to remove bootconfig data from initrd while boot 2020-05-06 09:04:11 -04:00
Makefile kbuild: use CONFIG_CC_VERSION_TEXT to construct LINUX_COMPILER macro 2020-05-12 13:28:33 +09:00
noinitramfs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 167 2019-05-30 11:26:39 -07:00
version.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00