19.01.2021 20:40, Andy Lutomirski пишет:
The implementation was rather buggy. It unconditionally marked PTEs
read-only, even for VM_SHARED mappings. I'm not sure whether this is
actually a problem, but it certainly seems unwise. More importantly, it
released the mmap lock before flushing the TLB, which could allow a racing
CoW operation to falsely believe that the underlying memory was not
writable.
I can't find any users at all of this mechanism, so just remove it.
Cc: Andrea Arcangeli <aarca...@redhat.com>
Cc: Linux-MM <linux...@kvack.org>
Cc: Jason Gunthorpe <j...@ziepe.ca>
Cc: x...@kernel.org
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Matthew Wilcox <wi...@infradead.org>
Cc: Jann Horn <ja...@google.com>
Cc: Jan Kara <j...@suse.cz>
Cc: Yu Zhao <yuz...@google.com>
Cc: Peter Xu <pet...@redhat.com>
Cc: Stas Sergeev <s...@list.ru>
Cc: Brian Gerst <brge...@gmail.com>
Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
Acked-by: st...@yandex.ru
dosemu2 just uses mprotect().
The BIOSSEG stuff in vm86_32.c is also
unused btw.
