9326e0f85b
Originally, bpfilter_umh was linked with -static only when
CONFIG_BPFILTER_UMH=y.
Commit 8a2cc0505cc4 ("bpfilter: use 'userprogs' syntax to build
bpfilter_umh") silently, accidentally dropped the CONFIG_BPFILTER_UMH=y
test in the Makefile. Revive it in order to link it dynamically when
CONFIG_BPFILTER_UMH=m.
Since commit b1183b6dca3e ("bpfilter: check if $(CC) can link static
libc in Kconfig"), the compiler must be capable of static linking to
enable CONFIG_BPFILTER_UMH, but it requires more than needed.
To loosen the compiler requirement, I changed the dependency as follows:
depends on CC_CAN_LINK
depends on m || CC_CAN_LINK_STATIC
If CONFIG_CC_CAN_LINK_STATIC in unset, CONFIG_BPFILTER_UMH is restricted
to 'm' or 'n'.
In theory, CONFIG_CC_CAN_LINK is not required for CONFIG_BPFILTER_UMH=y,
but I did not come up with a good way to describe it.
Fixes: 8a2cc0505cc4 ("bpfilter: use 'userprogs' syntax to build bpfilter_umh")
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
Link: https://lore.kernel.org/bpf/20200701092644.762234-1-masahiroy@kernel.org
21 lines
584 B
Makefile
21 lines
584 B
Makefile
# SPDX-License-Identifier: GPL-2.0
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#
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# Makefile for the Linux BPFILTER layer.
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#
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userprogs := bpfilter_umh
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bpfilter_umh-objs := main.o
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userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi
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ifeq ($(CONFIG_BPFILTER_UMH), y)
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# builtin bpfilter_umh should be linked with -static
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# since rootfs isn't mounted at the time of __init
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# function is called and do_execv won't find elf interpreter
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userldflags += -static
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endif
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$(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
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obj-$(CONFIG_BPFILTER_UMH) += bpfilter.o
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bpfilter-objs += bpfilter_kern.o bpfilter_umh_blob.o
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