[Bug 256806] panic: vm_page_free_prep: freeing mapped page

From: <bugzilla-noreply_at_freebsd.org>
Date: Wed, 30 Jun 2021 14:12:27 +0000
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256806

--- Comment #9 from Mark Johnston <markj_at_FreeBSD.org> ---
(In reply to Niels Bakker from comment #8)
The mapping address is the same as the beginning of the vm_map_entry range.  I
believe it isn't possible for a page to be mapped into the pmap after the
pmap_remove() call, since we're in execve and other threads are suspended.

One other possibility is that the PTE was damaged somehow (e.g., due to a
hardware bit-flip), so PG_V is clear and pmap_remove() skipped it. 
Unfortunately, I think we can't check this because page table pages are not
included in minidumps.

Has the panic occurred more than once?

-- 
You are receiving this mail because:
You are the assignee for the bug.
Received on Wed Jun 30 2021 - 14:12:27 UTC

Original text of this message