RE: [PATCH v2 0/3] More machine check recovery fixes

From: Luck, Tony
Date: Wed Aug 18 2021 - 12:14:43 EST


> Changes since v1:
> 1) Fix bug in kill_me_never() that forgot to clear p->mce_count so
> repeated recovery in the same task would trigger the panic for
> "Machine checks to different user pages"
> [Note to Jue Wang ... this *might* be why your test that injects
> two errors into the same buffer passed to a write(2) syscall
> failed with this message]

I recreated Jue's specific test today with uncorrected errors in two
pages passed to a write(2) syscall.

buf = alloc(2 pages);
inject(buf + 0x440);
inject*buf + 0x11c0);
n = write(fd, buf, 8K);

Result was that the write returned 0x440 (i.e. bytes written up to the
first poison location).

-Tony