Hi I tried to build Linux kernel 4.5-rc3-git1 today. On APM Mustang. And it failed: ------------------------------------------------------------------------ /tmp/ccKTs5Cd.s: Assembler messages: /tmp/ccKTs5Cd.s:1617: Error: selected processor does not support `ldaddal w0,w30,[x1]' /tmp/ccKTs5Cd.s:1622: Error: attempt to move .org backwards scripts/Makefile.build:258: recipe for target 'init/do_mounts.o' failed ------------------------------------------------------------------------ Checked what it means and got to commit: ------------------------------------------------------------------------ commit c09d6a04d17d730b0463207a26ece082772b59ee Author: Will Deacon <will.deacon@xxxxxxx> Date: Tue Feb 3 16:14:13 2015 +0000 arm64: atomics: patch in lse instructions when supported by the CPU On CPUs which support the LSE atomic instructions introduced in ARMv8.1, it makes sense to use them in preference to ll/sc sequences. This patch introduces runtime patching of atomic_t and atomic64_t routines so that the call-site for the out-of-line ll/sc sequences is patched with an LSE atomic instruction when we detect that the CPU supports it. If binutils is not recent enough to assemble the LSE instructions, then the ll/sc sequences are inlined as though CONFIG_ARM64_LSE_ATOMICS=n. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Will Deacon <will.deacon@xxxxxxx> ------------------------------------------------------------------------ If I revert arch/arm64/Makefile change (so disable use of LSE instructions) kernel builds. So I contacted Will Deacon, told him about a bug and that it is with binutils 2.26 and gcc 6-prerelease. He replied that failure is gcc6 related and gave me a link: https://gcc.gnu.org/ml/gcc-patches/2016-02/msg00313.html Thread mentions also kernel patch for this issue. _______________________________________________ arm mailing list arm@xxxxxxxxxxxxxxxxxxxxxxx http://lists.fedoraproject.org/admin/lists/arm@xxxxxxxxxxxxxxxxxxxxxxx
