Messages in this thread |  | | Date | Mon, 9 Apr 2018 18:18:16 +0200 (CEST) | From | Sebastian Ott <> | Subject | Re: [bisected] 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91 oopses on s390 |
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On Fri, 6 Apr 2018, Kees Cook wrote: > On Fri, Apr 6, 2018 at 2:47 AM, Sebastian Ott <sebott@linux.vnet.ibm.com> wrote: > > Today's kernel oopsed on s390. Bisect points to: > > 3c8ba0d61d04 ("kernel.h: Retain constant expression output for max()/min()") > > > > [ 1.898277] dasd-eckd 0.0.3304: DASD with 4 KB/block, 21636720 KB total size, 48 KB/track, compatible disk layout > > [ 1.898308] ------------[ cut here ]------------ > > [ 1.898310] kernel BUG at block/bio.c:1798! > > Well that's extremely bad. :(
What happened is that the bio build by the partition detection code was attempted to be split by the block layer because the block queue had a max_sector setting of 0. blk_queue_max_hw_sectors uses min_not_zero.
Both of the following return 0 on my machine: + pr_warn("%u\n", min_not_zero(100, 1000)); + pr_warn("%u\n", min_not_zero(1000, 100));
So, we now know what failed...the question is why?
Sebastian
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