diff options
| author | Masahiro Yamada <masahiroy@kernel.org> | 2020-07-01 18:26:44 +0900 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-07-14 12:37:06 -0700 |
| commit | 9326e0f85bfaf0578d40f5357f8143ec857469f5 (patch) | |
| tree | b608e7df549dc65400597477fc019153d3a8946b | |
| parent | a4fa458950b40d3849946daa32466392811a3716 (diff) | |
bpfilter: Allow to build bpfilter_umh as a module without static library
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
| -rw-r--r-- | net/bpfilter/Kconfig | 10 | ||||
| -rw-r--r-- | net/bpfilter/Makefile | 2 |
2 files changed, 8 insertions, 4 deletions
diff --git a/net/bpfilter/Kconfig b/net/bpfilter/Kconfig index 84015ef3ee27..73d0b12789f1 100644 --- a/net/bpfilter/Kconfig +++ b/net/bpfilter/Kconfig @@ -9,12 +9,14 @@ menuconfig BPFILTER if BPFILTER config BPFILTER_UMH tristate "bpfilter kernel module with user mode helper" - depends on CC_CAN_LINK_STATIC + depends on CC_CAN_LINK + depends on m || CC_CAN_LINK_STATIC default m help This builds bpfilter kernel module with embedded user mode helper - Note: your toolchain must support building static binaries, since - rootfs isn't mounted at the time when __init functions are called - and do_execv won't be able to find the elf interpreter. + Note: To compile this as built-in, your toolchain must support + building static binaries, since rootfs isn't mounted at the time + when __init functions are called and do_execv won't be able to find + the elf interpreter. endif diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile index f23b53294fba..cdac82b8c53a 100644 --- a/net/bpfilter/Makefile +++ b/net/bpfilter/Makefile @@ -7,10 +7,12 @@ userprogs := bpfilter_umh bpfilter_umh-objs := main.o userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi +ifeq ($(CONFIG_BPFILTER_UMH), y) # builtin bpfilter_umh should be linked with -static # since rootfs isn't mounted at the time of __init # function is called and do_execv won't find elf interpreter userldflags += -static +endif $(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh |