kernel-fxtec-pro1x/tools/objtool
Josh Poimboeuf 319b324649 objtool: Support Clang non-section symbols in ORC generation
commit e81e0724432542af8d8c702c31e9d82f57b1ff31 upstream.

When compiling the kernel with AS=clang, objtool produces a lot of
warnings:

  warning: objtool: missing symbol for section .text
  warning: objtool: missing symbol for section .init.text
  warning: objtool: missing symbol for section .ref.text

It then fails to generate the ORC table.

The problem is that objtool assumes text section symbols always exist.
But the Clang assembler is aggressive about removing them.

When generating relocations for the ORC table, objtool always tries to
reference instructions by their section symbol offset.  If the section
symbol doesn't exist, it bails.

Do a fallback: when a section symbol isn't available, reference a
function symbol instead.

Reported-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/669
Link: https://lkml.kernel.org/r/9a9cae7fcf628843aabe5a086b1a3c5bf50f42e8.1585761021.git.jpoimboe@redhat.com
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05 11:08:31 +01:00
..
arch/x86 x86/decoder: Add TEST opcode to Group3-2 2020-02-24 08:34:50 +01:00
Documentation
.gitignore
arch.h
Build
builtin-check.c
builtin-orc.c
builtin.h
cfi.h
check.c objtool: Fix noreturn detection for ignored functions 2020-10-01 13:14:50 +02:00
check.h
elf.c
elf.h
Makefile kbuild: support LLVM=1 to switch the default tools to Clang/LLVM 2020-09-26 18:01:32 +02:00
objtool.c
orc.h
orc_dump.c objtool: Support Clang non-section symbols in ORC dump 2020-05-02 17:25:57 +02:00
orc_gen.c objtool: Support Clang non-section symbols in ORC generation 2020-11-05 11:08:31 +01:00
special.c
special.h
sync-check.sh
warn.h