arm64/alternatives: move length validation inside the subsection

Commit f7b93d4294 ("arm64/alternatives: use subsections for replacement
sequences") breaks LLVM's integrated assembler, because due to its
one-pass design, it cannot compute instruction sequence lengths before the
layout for the subsection has been finalized. This change fixes the build
by moving the .org directives inside the subsection, so they are processed
after the subsection layout is known.

Fixes: f7b93d4294 ("arm64/alternatives: use subsections for replacement sequences")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1078
Link: https://lore.kernel.org/r/20200730153701.3892953-1-samitolvanen@google.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Sami Tolvanen 2020-07-30 08:37:01 -07:00 committed by Will Deacon
parent 7b7891c7bd
commit 966a0acce2

View File

@ -77,9 +77,9 @@ static inline void apply_alternatives_module(void *start, size_t length) { }
"663:\n\t" \
newinstr "\n" \
"664:\n\t" \
".previous\n\t" \
".org . - (664b-663b) + (662b-661b)\n\t" \
".org . - (662b-661b) + (664b-663b)\n" \
".org . - (662b-661b) + (664b-663b)\n\t" \
".previous\n" \
".endif\n"
#define __ALTERNATIVE_CFG_CB(oldinstr, feature, cfg_enabled, cb) \