kernel/linux.git/net/bpfilter/Makefile, branch v6.6.131

bpfilter: Allow to build bpfilter_umh as a module without static library

2020-07-14T19:37:06+00:00

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 Signed-off-by: Masahiro Yamada Signed-off-by: Alexei Starovoitov Tested-by: Michal Kubecek Link: https://lore.kernel.org/bpf/20200701092644.762234-1-masahiroy@kernel.org

bpfilter: use 'userprogs' syntax to build bpfilter_umh

2020-05-17T09:52:01+00:00

The user mode helper should be compiled for the same architecture as the kernel. This Makefile reused the 'hostprogs' syntax by overriding HOSTCC with CC. Use the new syntax 'userprogs' to fix the Makefile mess. Signed-off-by: Masahiro Yamada Acked-by: Sam Ravnborg

bpfilter: match bit size of bpfilter_umh to that of the kernel

2020-05-17T09:52:01+00:00

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

kbuild: rename hostprogs-y/always to hostprogs/always-y

2020-02-03T16:53:07+00:00

In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada

treewide: prefix header search paths with $(srctree)/

2019-05-18T02:49:57+00:00

Currently, the Kbuild core manipulates header search paths in a crazy way [1]. To fix this mess, I want all Makefiles to add explicit $(srctree)/ to the search paths in the srctree. Some Makefiles are already written in that way, but not all. The goal of this work is to make the notation consistent, and finally get rid of the gross hacks. Having whitespaces after -I does not matter since commit 48f6e3cf5bc6 ("kbuild: do not drop -I without parameter"). [1]: https://patchwork.kernel.org/patch/9632347/ Signed-off-by: Masahiro Yamada

bpfilter: re-add header search paths to tools include to fix build error

2019-02-23T21:34:40+00:00

I thought header search paths to tools/include(/uapi) were unneeded, but it looks like a build error occurs depending on the compiler. Commit 303a339f30a9 ("bpfilter: remove extra header search paths for bpfilter_umh") reintroduced the build error fixed by commit ae40832e53c3 ("bpfilter: fix a build err"). Apology for the breakage, and thanks to Guenter for reporting this. Fixes: 303a339f30a9 ("bpfilter: remove extra header search paths for bpfilter_umh") Reported-by: Guenter Roeck Signed-off-by: Masahiro Yamada Tested-by: Guenter Roeck Signed-off-by: David S. Miller

bpfilter: remove extra header search paths for bpfilter_umh

2019-02-04T04:11:43+00:00

Currently, the header search paths -Itools/include and -Itools/include/uapi are not used. Let's drop the unused code. We can remove -I. too by fixing up one C file. Signed-off-by: Masahiro Yamada Signed-off-by: David S. Miller

kbuild: Rename HOSTLDFLAGS to KBUILD_HOSTLDFLAGS

2018-07-17T16:18:05+00:00

In preparation for enabling command line LDFLAGS, re-name HOSTLDFLAGS to KBUILD_HOSTLDFLAGS as the internal use only flags. This should not have any visible effects. Signed-off-by: Laura Abbott Signed-off-by: Masahiro Yamada

kbuild: Rename HOSTCFLAGS to KBUILD_HOSTCFLAGS

2018-07-17T16:18:05+00:00

In preparation for enabling command line CFLAGS, re-name HOSTCFLAGS to KBUILD_HOSTCFLAGS as the internal use only flags. This should not have any visible effects. Signed-off-by: Laura Abbott Signed-off-by: Masahiro Yamada

bpfilter: include bpfilter_umh in assembly instead of using objcopy

2018-06-28T12:39:16+00:00

What we want here is to embed a user-space program into the kernel. Instead of the complex ELF magic, let's simply wrap it in the assembly with the '.incbin' directive. Signed-off-by: Masahiro Yamada Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller