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![]() In assembly, many instances of __emit_inst(x) expand to a directive. In a few places __emit_inst(x) is used as an assembler macro argument. For example, in arch/arm64/kvm/hyp/entry.S ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) expands to the following by the C preprocessor: alternative_insn nop, .inst (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 Both comma and space are separators, with an exception that content inside a pair of parentheses/quotes is not split, so the clang integrated assembler splits the arguments to: nop, .inst, (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 GNU as preprocesses the input with do_scrub_chars(). Its arm64 backend (along with many other non-x86 backends) sees: alternative_insn nop,.inst(0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # .inst(...) is parsed as one argument while its x86 backend sees: alternative_insn nop,.inst (0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # The extra space before '(' makes the whole .inst (...) parsed as two arguments The non-x86 backend's behavior is considered unintentional (https://sourceware.org/bugzilla/show_bug.cgi?id=25750). So drop the space separator inside `.inst (...)` to make the clang integrated assembler work. Suggested-by: Ilie Halip <ilie.halip@gmail.com> Signed-off-by: Fangrui Song <maskray@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Link: https://github.com/ClangBuiltLinux/linux/issues/939 Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> |
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.. | ||
boot | ||
configs | ||
crypto | ||
include | ||
kernel | ||
kvm | ||
lib | ||
mm | ||
net | ||
xen | ||
Kbuild | ||
Kconfig | ||
Kconfig.debug | ||
Kconfig.platforms | ||
Makefile |