On 12/7/21 23:07, John David Anglin wrote: > On 2021-12-05 3:46 p.m., Helge Deller wrote: >>> 10574: 43 ff ff 40 ldb 1fa0(sr3,r31),r31 >> This IIR is strange. We most likely don't touch userspace at this stage >> when the kernel boots, and... > I'm thinking IIR is sometimes unreliable. I see the same value > printed for the tst-minsigstksz-5 fault yet the actual fault > instruction was "ldi 1,r25". Good finding. It seems to be at least always unreliable if we get a trap 7 (Instruction access rights). In that case the CPU couldn't execute the instruction due to missing execute permissions. I believe the CPU simply didn't fetched the instruction and as such has stale content in IIR. I'm sending a patch to the list which marks IIR with a magic value in that case. Helge
