kernel/linux.git/arch/mips/vdso, branch linux-5.9.y

kbuild: explicitly specify the build id style

2020-11-18T18:22:07+00:00

[ Upstream commit a968433723310f35898b4a2f635a7991aeef66b1 ] ld's --build-id defaults to "sha1" style, while lld defaults to "fast". The build IDs are very different between the two, which may confuse programs that reference them. Signed-off-by: Bill Wendling Acked-by: David S. Miller Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-08-09T21:10:26+00:00

Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler

mips/vdso: Fix resource leaks in genvdso.c

2020-07-16T09:05:37+00:00

Close "fd" before the return of map_vdso() and close "out_file" in main(). Signed-off-by: Peng Fan Signed-off-by: Thomas Bogendoerfer

MIPS: fix vdso different address spaces

2020-07-16T08:53:46+00:00

sparse report build warning as follows: arch/mips/vdso/vdso-n32-image.c:13:35: incorrect type in assignment (different address spaces) @@ expected void *[usertype] vdso @@ got void [noderef] * @@ Reported-by: kernel test robot Signed-off-by: Sunguoyun Signed-off-by: Thomas Bogendoerfer

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

MIPS: VDSO: Allow ld.lld to link the VDSO

2020-05-12T08:02:11+00:00

Currently, when linking with ld.lld, this warning pops up: arch/mips/vdso/Makefile:70: MIPS VDSO requires binutils >= 2.25 CONFIG_LD_VERSION is set with scripts/ld-version.sh, which is specific to GNU ld. It returns 0 for ld.lld so CONFIG_MIPS_LD_CAN_LINK_VDSO does not set. ld.lld has a completely different versioning scheme (as it follows LLVM's versioning) and it does not have the issue mentioned in the comment block so it should be allowed to link the VDSO. With this patch, the VDSO successfully links and shows P_MIPS_PC32 in vgettimeofday.o. $ llvm-objdump -Dr arch/mips/vdso/vgettimeofday.o | grep R_MIPS_PC32 00000024: R_MIPS_PC32 _start 000000b0: R_MIPS_PC32 _start 000002bc: R_MIPS_PC32 _start 0000036c: R_MIPS_PC32 _start 00000468: R_MIPS_PC32 _start Reported-by: Dmitry Golovin Signed-off-by: Nathan Chancellor Link: https://github.com/ClangBuiltLinux/linux/issues/785 Link: https://github.com/llvm/llvm-project/commit/e364e2e9ce50c12eb2bf093560e1a1a8544d455a Signed-off-by: Thomas Bogendoerfer

MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO

2020-05-12T08:02:00+00:00

Currently, the VDSO is being linked through $(CC). This does not match how the rest of the kernel links objects, which is through the $(LD) variable. When clang is built in a default configuration, it first attempts to use the target triple's default linker then the system's default linker, unless told otherwise through -fuse-ld=... We do not use -fuse-ld= because it can be brittle and we have support for invoking $(LD) directly. See commit fe00e50b2db8c ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO") and commit 691efbedc60d2 ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO") for examples of doing this in the VDSO. Do the same thing here. Replace the custom linking logic with $(cmd_ld) and ldflags-y so that $(LD) is respected. We need to explicitly add two flags to the linker that were implicitly passed by the compiler: -G 0 (which comes from ccflags-vdso) and --eh-frame-hdr. Before this patch (generated by adding '-v' to VDSO_LDFLAGS): /libexec/gcc/mips64-linux/9.3.0/collect2 \ -plugin /libexec/gcc/mips64-linux/9.3.0/liblto_plugin.so \ -plugin-opt=/libexec/gcc/mips64-linux/9.3.0/lto-wrapper \ -plugin-opt=-fresolution=/tmp/ccGEi5Ka.res \ --eh-frame-hdr \ -G 0 \ -EB \ -mips64r2 \ -shared \ -melf64btsmip \ -o arch/mips/vdso/vdso.so.dbg.raw \ -L/lib/gcc/mips64-linux/9.3.0/64 \ -L/lib/gcc/mips64-linux/9.3.0 \ -L/lib/gcc/mips64-linux/9.3.0/../../../../mips64-linux/lib \ -Bsymbolic \ --no-undefined \ -soname=linux-vdso.so.1 \ -EB \ --hash-style=sysv \ --build-id \ -T arch/mips/vdso/vdso.lds \ arch/mips/vdso/elf.o \ arch/mips/vdso/vgettimeofday.o \ arch/mips/vdso/sigreturn.o After this patch: /bin/mips64-linux-ld \ -m elf64btsmip \ -Bsymbolic \ --no-undefined \ -soname=linux-vdso.so.1 \ -EB \ -nostdlib \ -shared \ -G 0 \ --eh-frame-hdr \ --hash-style=sysv \ --build-id \ -T arch/mips/vdso/vdso.lds \ arch/mips/vdso/elf.o \ arch/mips/vdso/vgettimeofday.o arch/mips/vdso/sigreturn.o \ -o arch/mips/vdso/vdso.so.dbg.raw Note that we leave behind -mips64r2. Turns out that ld ignores it (see get_emulation in ld/ldmain.c). This is true of current trunk and 2.23, which is the minimum supported version for the kernel: https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/ldmain.c;hb=aa4209e7b679afd74a3860ce25659e71cc4847d5#l593 https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/ldmain.c;hb=a55e30b51bc6227d8d41f707654d0a5620978dcf#l641 Before this patch, LD=ld.lld did nothing: $ llvm-readelf -p.comment arch/mips/vdso/vdso.so.dbg | sed 's/(.*//' String dump of section '.comment': [ 0] ClangBuiltLinux clang version 11.0.0 After this patch, it does: $ llvm-readelf -p.comment arch/mips/vdso/vdso.so.dbg | sed 's/(.*//' String dump of section '.comment': [ 0] Linker: LLD 11.0.0 [ 62] ClangBuiltLinux clang version 11.0.0 Link: https://github.com/ClangBuiltLinux/linux/issues/785 Signed-off-by: Nathan Chancellor Signed-off-by: Thomas Bogendoerfer

MIPS: VDSO: Move disabling the VDSO logic to Kconfig

2020-05-12T08:01:45+00:00

After commit 9553d16fa671 ("init/kconfig: Add LD_VERSION Kconfig"), we have access to GNU ld's version at configuration time. As a result, we can make it clearer under what configuration circumstances the MIPS VDSO needs to be disabled. This is a prerequisite for getting rid of the MIPS VDSO binutils warning and linking the VDSO when LD is ld.lld. Wrapping the call to ld-ifversion with CONFIG_LD_IS_LLD does not work because the config values are wiped away during 'make clean'. Signed-off-by: Nathan Chancellor Signed-off-by: Thomas Bogendoerfer

.gitignore: add SPDX License Identifier

2020-03-25T10:50:48+00:00

Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

MIPS: vdso: Wrap -mexplicit-relocs in cc-option

2020-02-19T18:30:10+00:00

Clang does not support this option and errors out: clang-11: error: unknown argument: '-mexplicit-relocs' Clang does not appear to need this flag like GCC does because the jalr check that was added in commit 976c23af3ee5 ("mips: vdso: add build time check that no 'jalr t9' calls left") passes just fine with $ make ARCH=mips CC=clang CROSS_COMPILE=mipsel-linux-gnu- malta_defconfig arch/mips/vdso/ even before commit d3f703c4359f ("mips: vdso: fix 'jalr t9' crash in vdso code"). -mrelax-pic-calls has been supported since clang 9, which is the earliest version that could build a working MIPS kernel, and it is the default for clang so just leave it be. Fixes: d3f703c4359f ("mips: vdso: fix 'jalr t9' crash in vdso code") Link: https://github.com/ClangBuiltLinux/linux/issues/890 Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: clang-built-linux@googlegroups.com