On 12/10/2015 06:05 PM, kbuild test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > head: 8225f4e85cb03daea14661380745886ce01fd83a > commit: 0dd08f12cafd7868be55bc10ebcd4ea13880860b [5266/5426] UBSAN: run-time undefined behavior sanity checker > config: x86_64-randconfig-s5-12102221 (attached as .config) > reproduce: > git checkout 0dd08f12cafd7868be55bc10ebcd4ea13880860b > # save the attached .config to linux build tree > make ARCH=x86_64 > > Note: it may well be a FALSE warning. FWIW you are at least aware of it now. > http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings > This is certainly a false positive. It seems that UBSAN could make gcc more stupid and increase number of maybe-uninitialized false-positives. > All warnings (new ones prefixed by >>): > > arch/x86/kernel/cpu/mcheck/mce.c: In function 'do_machine_check': >>> arch/x86/kernel/cpu/mcheck/mce.c:884:5: warning: 'order' may be used uninitialized in this function [-Wmaybe-uninitialized] > if (order == 1) { > ^ > arch/x86/kernel/cpu/mcheck/mce.c:984:6: note: 'order' was declared here > int order; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>