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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-23 15:13:45 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-23 15:13:45 -0800 |
| commit | 414eece95b98b209cef0f49cfcac108fd00b8ced (patch) | |
| tree | 82de6f145dee0b6261d4a62cb2f9d7d143ace44b /scripts/Makefile.lib | |
| parent | 6dd580b93da8de5cab4ac1f24f343086318b664e (diff) | |
| parent | 5e95325fbbbdea96de91e7bdb05fe95a3031e37d (diff) | |
Merge tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull more clang LTO updates from Kees Cook:
"Clang LTO x86 enablement.
Full disclosure: while this has _not_ been in linux-next (since it
initially looked like the objtool dependencies weren't going to make
v5.12), it has been under daily build and runtime testing by Sami for
quite some time. These x86 portions have been discussed on lkml, with
Peter, Josh, and others helping nail things down.
The bulk of the changes are to get objtool working happily. The rest
of the x86 enablement is very small.
Summary:
- Generate __mcount_loc in objtool (Peter Zijlstra)
- Support running objtool against vmlinux.o (Sami Tolvanen)
- Clang LTO enablement for x86 (Sami Tolvanen)"
Link: https://lore.kernel.org/lkml/20201013003203.4168817-26-samitolvanen@google.com/
Link: https://lore.kernel.org/lkml/cover.1611263461.git.jpoimboe@redhat.com/
* tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: lto: force rebuilds when switching CONFIG_LTO
x86, build: allow LTO to be selected
x86, cpu: disable LTO for cpu.c
x86, vdso: disable LTO only for vDSO
kbuild: lto: postpone objtool
objtool: Split noinstr validation from --vmlinux
x86, build: use objtool mcount
tracing: add support for objtool mcount
objtool: Don't autodetect vmlinux.o
objtool: Fix __mcount_loc generation with Clang's assembler
objtool: Add a pass for generating __mcount_loc
Diffstat (limited to 'scripts/Makefile.lib')
| -rw-r--r-- | scripts/Makefile.lib | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 2301babd3fbc..9f2531567c0e 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -222,6 +222,18 @@ dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ $(addprefix -I,$(DTC_INCLUDE)) \ -undef -D__DTS__ +# Objtool arguments are also needed for modfinal with LTO, so we define +# then here to avoid duplication. +objtool_args = \ + $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \ + $(if $(part-of-module), --module,) \ + $(if $(CONFIG_FRAME_POINTER),, --no-fp) \ + $(if $(or $(CONFIG_GCOV_KERNEL),$(CONFIG_LTO_CLANG)), \ + --no-unreachable,) \ + $(if $(CONFIG_RETPOLINE), --retpoline,) \ + $(if $(CONFIG_X86_SMAP), --uaccess,) \ + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount,) + # Useful for describing the dependency of composite objects # Usage: # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) |