On 07.11.2019 16:45, Kamil Rytarowski wrote: > On 07.11.2019 16:26, Martin Husemann wrote: >> On Thu, Nov 07, 2019 at 02:53:08PM +0100, Kamil Rytarowski wrote: >>> On 07.11.2019 14:25, Valery Ushakov wrote: >>>> If the sanitizer does complain about other uses, there is little point >>>> in fixing one instance and not the others. >>> >>> We already agreed with Christos that this is appeasing of GCC. If you >>> want to scan the whole kernel (or whole C) file for more occurrences of >>> violations - please go for it. >> >> No. The commit needs to be reverted, and then >> >> a) either the root cause for the unaligned address be fixed or >> b) some other means be found to make the sanitizer shut up >> >> As uwe said: papering over a tiny detail that *never* hits in the real >> world but potentialy hiding a real issue is not the way to go. >> > > I don't have a readily available reproducer locally but it was breaking > syzbot from booting after the switch to gcc8. I will fix it differently > aligning the whole struct (so the same approach as we use in userland) > and backout this change. > Please review: http://netbsd.org/~kamil/patch-00194-disklabel-alignment.txt This patch works for me. Patch inspired by: Avoid misaligned access in disklabel(8) in find_label() https://github.com/NetBSD/src/commit/19bd3d170c8fd67052ca4ca20151cd77d893ab88 After landing it I will revert "Avoid unaligned pointer arithmetic in check_label_magic()".
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