linux-dev/arch/um/Makefile, branch master

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

2022-09-21T07:11:42Z

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

Revert "um: clang: Strip out -mno-global-merge from USER_CFLAGS"

2022-04-01T15:05:28Z

This reverts commit 6580c5c18fb3df2b11c5e0452372f815deeff895. This patch is buggy, as noted in the patch linked below. The root cause has been solved by removing '-mno-global-merge' for the entire kernel. Link: https://lore.kernel.org/r/20220322173547.677760-1-nathan@kernel.org/ Signed-off-by: Nathan Chancellor Reviewed-by: David Gow Reviewed-by: Kees Cook Signed-off-by: Masahiro Yamada

um: clang: Strip out -mno-global-merge from USER_CFLAGS

2022-03-11T09:51:41Z

The things built with USER_CFLAGS don't seem to recognise it as a compiler option, and print a warning: clang: warning: argument unused during compilation: '-mno-global-merge' [-Wunused-command-line-argument] Fixes: 744814d2fa ("um: Allow builds with Clang") Signed-off-by: David Gow Reviewed-by: Nathan Chancellor Signed-off-by: Richard Weinberger

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

2021-08-09T23:23:39Z

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

2021-06-17T19:54:15Z

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

2020-07-07T02:13:10Z

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

2020-05-25T15:03:15Z

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/

2020-04-23T01:50:26Z

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

2019-07-10T15:05:09Z

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

um: remove unused filechk_gen_header in Makefile

2018-12-21T15:35:20Z

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