Hi, [adding linux-mm] On 12/16/20 1:54 AM, Toralf Förster wrote: > Hi, > > I got this recently at this hardened Gentoo Linux server: > > Linux mr-fox 5.10.1 #1 SMP Tue Dec 15 22:09:42 CET 2020 x86_64 Intel(R) > Xeon(R) CPU E5-1650 v3 @ 3.50GHz GenuineIntel GNU/Linux > > > Dec 15 23:31:51 mr-fox kernel: [ 1974.206972] > ================================================================================ > Dec 15 23:31:51 mr-fox kernel: [ 1974.206977] UBSAN: shift-out-of-bounds > in ./include/linux/log2.h:57:13 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206980] shift exponent 64 is too > large for 64-bit type 'long unsigned int' > Dec 15 23:31:51 mr-fox kernel: [ 1974.206982] CPU: 11 PID: 21051 Comm: > cc1 Tainted: G T 5.10.1 #1 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206984] Hardware name: ASUSTeK > COMPUTER INC. Z10PA-U8 Series/Z10PA-U8 Series, BIOS 3703 08/02/2018 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206985] Call Trace: > Dec 15 23:31:51 mr-fox kernel: [ 1974.206993] dump_stack+0x57/0x6a > Dec 15 23:31:51 mr-fox kernel: [ 1974.206996] ubsan_epilogue+0x5/0x40 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206999] > __ubsan_handle_shift_out_of_bounds.cold+0x61/0x10e > Dec 15 23:31:51 mr-fox kernel: [ 1974.207002] > ondemand_readahead.cold+0x16/0x21 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207007] > generic_file_buffered_read+0x452/0x890 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207011] new_sync_read+0x156/0x200 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207014] vfs_read+0xf8/0x190 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207016] ksys_read+0x65/0xe0 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207018] do_syscall_64+0x33/0x40 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207021] > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207024] RIP: 0033:0x7f01b2df198e > Dec 15 23:31:51 mr-fox kernel: [ 1974.207026] Code: c0 e9 b6 fe ff ff 50 > 48 8d 3d 66 c3 09 00 e8 59 e2 01 00 66 0f 1f 84 00 00 00 00 00 64 8b 04 > 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 66 0f 1f > 84 00 00 00 00 00 48 83 ec 28 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207028] RSP: 002b:00007fff2167e998 > EFLAGS: 00000246 ORIG_RAX: 0000000000000000 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207030] RAX: ffffffffffffffda RBX: > 0000000000000000 RCX: 00007f01b2df198e > Dec 15 23:31:51 mr-fox kernel: [ 1974.207032] RDX: 0000000000000000 RSI: > 00000000054dcc50 RDI: 0000000000000004 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207033] RBP: 00000000054dcc50 R08: > 00000000054dcc50 R09: 0000000000000000 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207034] R10: 0000000000000000 R11: > 0000000000000246 R12: 00000000054dc3b0 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207035] R13: 0000000000008000 R14: > 00000000054c9800 R15: 0000000000000000 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207037] > ================================================================================ > > > Known issue ? Not that I have heard about, but that's not conclusive. Looks to me like this is in mm/readahead.c: static unsigned long get_init_ra_size(unsigned long size, unsigned long max) { unsigned long newsize = roundup_pow_of_two(size); What filesystem? What workload? thanks. -- ~Randy