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| author | Nathan Chancellor <natechancellor@gmail.com> | 2020-11-19 13:46:56 -0700 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2020-12-01 22:45:36 +0900 |
| commit | 59612b24f78a0b61fe078ec9dff2e48e9cec52c0 (patch) | |
| tree | 27ef4914a69c9bc3cd88fab6d3a6f6c10d5d91d0 /arch/Kconfig | |
| parent | b8a9092330da2030496ff357272f342eb970d51b (diff) | |
| download | lwn-59612b24f78a0b61fe078ec9dff2e48e9cec52c0.tar.gz lwn-59612b24f78a0b61fe078ec9dff2e48e9cec52c0.zip | |
kbuild: Hoist '--orphan-handling' into Kconfig
Currently, '--orphan-handling=warn' is spread out across four different
architectures in their respective Makefiles, which makes it a little
unruly to deal with in case it needs to be disabled for a specific
linker version (in this case, ld.lld 10.0.1).
To make it easier to control this, hoist this warning into Kconfig and
the main Makefile so that disabling it is simpler, as the warning will
only be enabled in a couple places (main Makefile and a couple of
compressed boot folders that blow away LDFLAGS_vmlinx) and making it
conditional is easier due to Kconfig syntax. One small additional
benefit of this is saving a call to ld-option on incremental builds
because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN.
To keep the list of supported architectures the same, introduce
CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to
gain this automatically after all of the sections are specified and size
asserted. A special thanks to Kees Cook for the help text on this
config.
Link: https://github.com/ClangBuiltLinux/linux/issues/1187
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 56b6ccc0e32d..ba4e966484ab 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1028,6 +1028,15 @@ config HAVE_STATIC_CALL_INLINE bool depends on HAVE_STATIC_CALL +config ARCH_WANT_LD_ORPHAN_WARN + bool + help + An arch should select this symbol once all linker sections are explicitly + included, size-asserted, or discarded in the linker scripts. This is + important because we never want expected sections to be placed heuristically + by the linker, since the locations of such sections can change between linker + versions. + source "kernel/gcov/Kconfig" source "scripts/gcc-plugins/Kconfig" |