Disclaimer: I have very little experience with the internals of the GNU toolchain, and this maybe manifests only in qemu; feel free to close NOTABUG. Version-Release number of selected component (if applicable): gcc-4.1.1-9 To reproduce: (/sbin/sysctl) crashes with SIGILL on rawhide in qemu. binutils have recently started using new byte sequences for .align, at least if the target architecture is i686. For some reason the i686-only sequence appears in crtfastmath.o: 83: 0f ae 95 e4 fd ff ff ldmxcsr 0xfffffde4(%ebp) 8a: 66 data16 8b: 0f 1f (bad) 8d: 44 inc %esp 8e: 00 00 add %al,(%eax) This byte sequence is currently executed only if SSE is supported, so this might cause crashes only in qemu - this is the first time I've heard about them, I don't know. Unfortunately I can't find a reason why the i686-only sequence is used; AFAICS (when rebuilding gcc on fc5) crtfastmath.c is compiled with -march=i386 -mtune=generic. Is gas perhaps switching to i686 automatically after encountering an i686-only instruction?
Should be fixed in gcc-4.1.1-14, which has been rebuilt with a fixed assembler. Anyway, guess qemu should support the nopl insns, if it pretends to be a '6' or 'f' family CPU. *** This bug has been marked as a duplicate of 200330 ***