Re: [PATCH v2] crypto: Fix divide error in do_xor_speed()

[Herbert Xu]

On Thu, Dec 31, 2020 at 12:33:18AM +0300, Kirill Tkhai wrote:
> crypto: Fix divide error in do_xor_speed()
> 
> From: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
> 
> 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")
> Signed-off-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
> Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---
> 
> v2: New Year resend :) Added fixes tag.
>  crypto/xor.c |    2 ++
>  1 file changed, 2 insertions(+)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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