kernel/linux.git/arch/um/Makefile, branch v5.15.208

um: let 'make clean' properly clean underlying SUBARCH as well

2025-06-04T12:38:08+00:00

[ Upstream commit ab09da75700e9d25c7dfbc7f7934920beb5e39b9 ] Building the kernel with O= is affected by stale in-tree build artifacts. So, if the source tree is not clean, Kbuild displays the following: $ make ARCH=um O=build defconfig make[1]: Entering directory '/.../linux/build' *** *** The source tree is not clean, please run 'make ARCH=um mrproper' *** in /.../linux *** make[2]: *** [/.../linux/Makefile:673: outputmakefile] Error 1 make[1]: *** [/.../linux/Makefile:248: __sub-make] Error 2 make[1]: Leaving directory '/.../linux/build' make: *** [Makefile:248: __sub-make] Error 2 Usually, running 'make mrproper' is sufficient for cleaning the source tree for out-of-tree builds. However, building UML generates build artifacts not only in arch/um/, but also in the SUBARCH directory (i.e., arch/x86/). If in-tree stale files remain under arch/x86/, Kbuild will reuse them instead of creating new ones under the specified build directory. This commit makes 'make ARCH=um clean' recurse into the SUBARCH directory. Reported-by: Shuah Khan Closes: https://lore.kernel.org/lkml/20250502172459.14175-1-skhan@linuxfoundation.org/ Signed-off-by: Masahiro Yamada Acked-by: Johannes Berg Reviewed-by: David Gow Reviewed-by: Shuah Khan Signed-off-by: Sasha Levin

um: Use HOST_DIR for mrproper

2023-07-23T11:47:33+00:00

commit a5a319ec2c2236bb96d147c16196d2f1f3799301 upstream. When HEADER_ARCH was introduced, the MRPROPER_FILES (then MRPROPER_DIRS) list wasn't adjusted, leaving SUBARCH as part of the path argument. This resulted in the "mrproper" target not cleaning up arch/x86/... when SUBARCH was specified. Since HOST_DIR is arch/$(HEADER_ARCH), use it instead to get the correct path. Cc: Richard Weinberger Cc: Anton Ivanov Cc: Johannes Berg Cc: Azeem Shaikh Cc: linux-um@lists.infradead.org Fixes: 7bbe7204e937 ("um: merge Makefile-{i386,x86_64}") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20230606222442.never.807-kees@kernel.org Signed-off-by: Greg Kroah-Hartman

arch: um: Mark the stack non-executable to fix a binutils warning

2022-10-12T07:53:27+00:00

[ Upstream commit bd71558d585ac61cfd799db7f25e78dca404dd7a ] Since binutils 2.39, ld will print a warning if any stack section is executable, which is the default for stack sections on files without a .note.GNU-stack section. This was fixed for x86 in commit ffcf9c5700e4 ("x86: link vdso and boot with -z noexecstack --no-warn-rwx-segments"), but remained broken for UML, resulting in several warnings: /usr/bin/ld: warning: arch/x86/um/vdso/vdso.o: missing .note.GNU-stack section implies executable stack /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker /usr/bin/ld: warning: .tmp_vmlinux.kallsyms1 has a LOAD segment with RWX permissions /usr/bin/ld: warning: .tmp_vmlinux.kallsyms1.o: missing .note.GNU-stack section implies executable stack /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker /usr/bin/ld: warning: .tmp_vmlinux.kallsyms2 has a LOAD segment with RWX permissions /usr/bin/ld: warning: .tmp_vmlinux.kallsyms2.o: missing .note.GNU-stack section implies executable stack /usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker /usr/bin/ld: warning: vmlinux has a LOAD segment with RWX permissions Link both the VDSO and vmlinux with -z noexecstack, fixing the warnings about .note.GNU-stack sections. In addition, pass --no-warn-rwx-segments to dodge the remaining warnings about LOAD segments with RWX permissions in the kallsyms objects. (Note that this flag is apparently not available on lld, so hide it behind a test for BFD, which is what the x86 patch does.) Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ffcf9c5700e49c0aee42dcba9a12ba21338e8136 Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107 Signed-off-by: David Gow Reviewed-by: Lukas Straub Tested-by: Lukas Straub Acked-by: Randy Dunlap # build-tested Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

kbuild: do not require sub-make for separate output tree builds

2021-08-09T23:23:39+00:00

As explained in commit 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefiles"), I want to stop using --include-dir some day. I already fixed up the top Makefile, but some arch Makefiles (mips, um, x86) still include check-in Makefiles without $(srctree)/. Fix them up so 'need-sub-make := 1' can go away for this case. Signed-off-by: Masahiro Yamada

um: allow not setting extra rpaths in the linux binary

2021-06-17T19:54:15+00:00

There doesn't seem to be any reason for the rpath being set in the binaries, at on systems that I tested on. On the other hand, setting rpath is actually harming binaries in some cases, e.g. if using nix-based compilation environments where /lib & /lib64 are not part of the actual environment. Add a new Kconfig option (under EXPERT, for less user confusion) that allows disabling the rpath additions. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

kbuild: remove cc-option test of -fno-stack-protector

2020-07-07T02:13:10+00:00

Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Acked-by: Ard Biesheuvel Reviewed-by: Nick Desaulniers

kbuild: remove {CLEAN,MRPROPER,DISTCLEAN}_DIRS

2020-05-25T15:03:15+00:00

Merge {CLEAN,MRPROPER,DISTCLEAN}_DIRS into {CLEAN,MRPROPER,DISTCLEAN}_FILES because the difference is just the -r option passed to the 'rm' command. Do likewise as commit 1634f2bfdb84 ("kbuild: remove clean-dirs syntax"). Signed-off-by: Masahiro Yamada

um: ensure `make ARCH=um mrproper` removes arch/$(SUBARCH)/include/generated/

2020-04-23T01:50:26+00:00

In this workflow: $ make ARCH=um defconfig && make ARCH=um -j8 [snip] $ make ARCH=um mrproper [snip] $ make ARCH=um defconfig O=./build_um && make ARCH=um -j8 O=./build_um [snip] CC scripts/mod/empty.o In file included from ../include/linux/types.h:6, from ../include/linux/mod_devicetable.h:12, from ../scripts/mod/devicetable-offsets.c:3: ../include/uapi/linux/types.h:5:10: fatal error: asm/types.h: No such file or directory 5 | #include | ^~~~~~~~~~~~~ compilation terminated. make[2]: *** [../scripts/Makefile.build:100: scripts/mod/devicetable-offsets.s] Error 1 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [/home/iha/sdb/opensource/lkmp/linux-kselftest.git/Makefile:1140: prepare0] Error 2 make[1]: Leaving directory '/home/iha/sdb/opensource/lkmp/linux-kselftest.git/build_um' make: *** [Makefile:180: sub-make] Error 2 The cause of the error was because arch/$(SUBARCH)/include/generated files weren't properly cleaned by `make ARCH=um mrproper`. Fixes: a788b2ed81ab ("kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build") Reported-by: Theodore Ts'o Suggested-by: Masahiro Yamada Signed-off-by: Vitor Massaru Iha Reviewed-by: Brendan Higgins Tested-by: Brendan Higgins Link: https://groups.google.com/forum/#!msg/kunit-dev/QmA27YEgEgI/hvS1kiz2CwAJ Signed-off-by: Masahiro Yamada

kbuild: remove src and obj from the top Makefile

2019-07-10T15:05:09+00:00

Replace $(src) and $(obj) with $(srctree) and $(objtree), respectively. Signed-off-by: Masahiro Yamada

um: remove unused filechk_gen_header in Makefile

2018-12-21T15:35:20+00:00

This is a leftover of commit ecba97d4aacf ("[PATCH] uml makefiles sanitized"). Signed-off-by: Masahiro Yamada