Hi I've got the following spew on mounting ext4 rootfs on kernel with UBSan: ================================================================================ UBSan: Undefined behaviour in ../fs/ext4/mballoc.c:2589:15 shift exponent -1 is negative CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc1+ #65 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 0000000000000010 0000000000000000 0000000000000001 ffff88013ab0f998 ffffffff82ade70a 0000000000000082 ffffffffffffffff ffff88013ab0f9a8 ffffffff819a5339 ffff88013ab0fa58 ffffffff819a5825 ffff8800bb0c7840 Call Trace: dump_stack (/home/andrew/linux/ubsan_x86//lib/dump_stackc:52) ubsan_epilogue (/home/andrew/linux/ubsan_x86//lib/ubsanc:159) __ubsan_handle_shift_out_of_bounds (/home/andrew/linux/ubsan_x86//lib/ubsanc:458) ? e1000_phy_get_info (/home/andrew/linux/ubsan_x86//drivers/net/ethernet/intel/e1000/e1000_hwc:3385 /home/andrew/linux/ubsan_x86//drivers/net/ethernet/intel/e1000/e1000_hwc:3455) ? put_online_cpus (/home/andrew/linux/ubsan_x86//kernel/cpuc:126) ? kmem_cache_create (/home/andrew/linux/ubsan_x86//mm/slab_commonc:431) ext4_mb_init (/home/andrew/linux/ubsan_x86//fs/ext4/mballocc:2589 (discriminator 1)) ? ext4_setup_system_zone (/home/andrew/linux/ubsan_x86//fs/ext4/block_validityc:150) ext4_fill_super (/home/andrew/linux/ubsan_x86//fs/ext4/superc:4101) ? register_shrinker (/home/andrew/linux/ubsan_x86//mm/vmscanc:207) mount_bdev (/home/andrew/linux/ubsan_x86//fs/superc:1004) ? ext4_calculate_overhead (/home/andrew/linux/ubsan_x86//fs/ext4/superc:3374) ext4_mount (/home/andrew/linux/ubsan_x86//fs/ext4/superc:5404) mount_fs (/home/andrew/linux/ubsan_x86//fs/superc:1106) vfs_kern_mount (/home/andrew/linux/ubsan_x86//fs/namespacec:908) do_mount (/home/andrew/linux/ubsan_x86//fs/namespacec:2292 /home/andrew/linux/ubsan_x86//fs/namespacec:2607) SyS_mount (/home/andrew/linux/ubsan_x86//fs/namespacec:2799 /home/andrew/linux/ubsan_x86//fs/namespacec:2774) mount_block_root (/home/andrew/linux/ubsan_x86//init/do_mountsc:364 /home/andrew/linux/ubsan_x86//init/do_mountsc:393) ? done_path_create (/home/andrew/linux/ubsan_x86//fs/nameic:3366) mount_root (/home/andrew/linux/ubsan_x86//init/do_mountsc:534) prepare_namespace (/home/andrew/linux/ubsan_x86//init/do_mountsc:592) kernel_init_freeable (/home/andrew/linux/ubsan_x86//init/mainc:903 /home/andrew/linux/ubsan_x86//init/mainc:1032) ? rest_init (/home/andrew/linux/ubsan_x86//init/mainc:931) kernel_init (/home/andrew/linux/ubsan_x86//init/mainc:936) ret_from_fork (/home/andrew/linux/ubsan_x86//arch/x86/kernel/entry_64S:348) ? rest_init (/home/andrew/linux/ubsan_x86//init/mainc:931) ================================================================================ And similar in another place: ================================================================================ UBSan: Undefined behaviour in ../fs/ext4/mballoc.c:1263:11 shift exponent -1 is negative CPU: 2 PID: 1426 Comm: mktemp Not tainted 3.18.0-rc1+ #65 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 0000000000000010 0000000000000000 0000000000000001 ffff8800babe7778 ffffffff82ade70a 00000000000000bc ffffffffffffffff ffff8800babe7788 ffffffff819a5339 ffff8800babe7838 ffffffff819a5825 ffff8800bb11ae68 Call Trace: dump_stack (/home/andrew/linux/ubsan_x86//lib/dump_stackc:52) ubsan_epilogue (/home/andrew/linux/ubsan_x86//lib/ubsanc:159) __ubsan_handle_shift_out_of_bounds (/home/andrew/linux/ubsan_x86//lib/ubsanc:458) ? ext4_mb_init_cache (/home/andrew/linux/ubsan_x86//include/linux/buffer_headh:286 /home/andrew/linux/ubsan_x86//fs/ext4/mballocc:961) mb_find_order_for_block (/home/andrew/linux/ubsan_x86//fs/ext4/mballocc:1263 (discriminator 1)) mb_find_extent (/home/andrew/linux/ubsan_x86//fs/ext4/mballocc:1512) ext4_mb_complex_scan_group (/home/andrew/linux/ubsan_x86//fs/ext4/mballocc:1947) ? pagecache_get_page (/home/andrew/linux/ubsan_x86//mm/filemapc:1102) ? ext4_mark_iloc_dirty (/home/andrew/linux/ubsan_x86//fs/ext4/inodec:4301 /home/andrew/linux/ubsan_x86//fs/ext4/inodec:4732) ext4_mb_regular_allocator (/home/andrew/linux/ubsan_x86//fs/ext4/ext4h:1346 /home/andrew/linux/ubsan_x86//fs/ext4/ext4h:2516 /home/andrew/linux/ubsan_x86//fs/ext4/ext4h:2551 /home/andrew/linux/ubsan_x86//fs/ext4/mballocc:2185) ? ext4_get_group_no_and_offset (/home/andrew/linux/ubsan_x86//fs/ext4/ballocc:61) ext4_mb_new_blocks (/home/andrew/linux/ubsan_x86//fs/ext4/mballocc:4475) ? ext4_inode_to_goal_block (/home/andrew/linux/ubsan_x86//fs/ext4/ballocc:870) ext4_ext_map_blocks (/home/andrew/linux/ubsan_x86//fs/ext4/extentsc:4455) ext4_map_blocks (/home/andrew/linux/ubsan_x86//fs/ext4/inodec:611) ? __ext4_new_inode (/home/andrew/linux/ubsan_x86//fs/ext4/iallocc:1061) ext4_getblk (/home/andrew/linux/ubsan_x86//fs/ext4/inodec:751) ext4_bread (/home/andrew/linux/ubsan_x86//fs/ext4/inodec:805) ext4_append (/home/andrew/linux/ubsan_x86//fs/ext4/nameic:66 (discriminator 3)) ext4_mkdir (/home/andrew/linux/ubsan_x86//fs/ext4/nameic:2404 /home/andrew/linux/ubsan_x86//fs/ext4/nameic:2452) ? security_inode_permission (/home/andrew/linux/ubsan_x86//security/securityc:573) vfs_mkdir (/home/andrew/linux/ubsan_x86//fs/nameic:3494) SyS_mkdir (/home/andrew/linux/ubsan_x86//fs/nameic:3517 /home/andrew/linux/ubsan_x86//fs/nameic:3500 /home/andrew/linux/ubsan_x86//fs/nameic:3527 /home/andrew/linux/ubsan_x86//fs/nameic:3525) system_call_fastpath (/home/andrew/linux/ubsan_x86//arch/x86/kernel/entry_64S:423) ================================================================================ -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
