From: Kirill Tkhai ktkhai@virtuozzo.com
commit 3c02e04fd4f57130e4fa75fab6f528f7a52db9b5 upstream.
crypto: Fix divide error in do_xor_speed()
From: Kirill Tkhai ktkhai@virtuozzo.com
Latest (but not only latest) linux-next panics with divide error on my QEMU setup.
The patch at the bottom of this message fixes the problem.
xor: measuring software checksum speed divide error: 0000 [#1] PREEMPT SMP KASAN PREEMPT SMP KASAN CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.10.0-next-20201223+ #2177 RIP: 0010:do_xor_speed+0xbb/0xf3 Code: 41 ff cc 75 b5 bf 01 00 00 00 e8 3d 23 8b fe 65 8b 05 f6 49 83 7d 85 c0 75 05 e8 84 70 81 fe b8 00 00 50 c3 31 d2 48 8d 7b 10 <f7> f5 41 89 c4 e8 58 07 a2 fe 44 89 63 10 48 8d 7b 08 e8 cb 07 a2 RSP: 0000:ffff888100137dc8 EFLAGS: 00010246 RAX: 00000000c3500000 RBX: ffffffff823f0160 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000808 RDI: ffffffff823f0170 RBP: 0000000000000000 R08: ffffffff8109c50f R09: ffffffff824bb6f7 R10: fffffbfff04976de R11: 0000000000000001 R12: 0000000000000000 R13: ffff888101997000 R14: ffff888101994000 R15: ffffffff823f0178 FS: 0000000000000000(0000) GS:ffff8881f7780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000220e000 CR4: 00000000000006a0 Call Trace: calibrate_xor_blocks+0x13c/0x1c4 ? do_xor_speed+0xf3/0xf3 do_one_initcall+0xc1/0x1b7 ? start_kernel+0x373/0x373 ? unpoison_range+0x3a/0x60 kernel_init_freeable+0x1dd/0x238 ? rest_init+0xc6/0xc6 kernel_init+0x8/0x10a ret_from_fork+0x1f/0x30 ---[ end trace 5bd3c1d0b77772da ]---
Fixes: c055e3eae0f1 ("crypto: xor - use ktime for template benchmarking") Cc: stable@vger.kernel.org Signed-off-by: Kirill Tkhai ktkhai@virtuozzo.com Acked-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- crypto/xor.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/crypto/xor.c +++ b/crypto/xor.c @@ -107,6 +107,8 @@ do_xor_speed(struct xor_block_template * preempt_enable();
// bytes/ns == GB/s, multiply by 1000 to get MB/s [not MiB/s] + if (!min) + min = 1; speed = (1000 * REPS * BENCH_SIZE) / (unsigned int)ktime_to_ns(min); tmpl->speed = speed;