PR/55658 CVS commit: src/sys/uvm

["Rin Okuyama" <rin%netbsd.org@localhost>]

The following reply was made to PR kern/55658; it has been noted by GNATS.

From: "Rin Okuyama" <rin%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/55658 CVS commit: src/sys/uvm
Date: Mon, 5 Oct 2020 04:48:24 +0000

 Module Name:	src
 Committed By:	rin
 Date:		Mon Oct  5 04:48:24 UTC 2020
 
 Modified Files:
 	src/sys/uvm: uvm_bio.c
 
 Log Message:
 PR kern/55658
 
 ubc_fault_page(): Ignore PG_RDONLY flag and always pmap_enter() the page
 with the permissions of the original access_type.
 
 It is the file system's responsibility to allocate blocks that is being
 modified by write(), before calling into UBC to fill the pages for that
 range. KASSERT() is added there to confirm that no clean page is mapped
 writable.
 
 Fix infinite loop in uvm_fault_internal(), observed on 16KB-page systems,
 where it continues to try to make a partially-backed page writable.
 
 No regression in ATF and KASSERT() does not fire on several architectures,
 as far as I can see.
 
 Fix suggested by chs. Thanks!
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.121 -r1.122 src/sys/uvm/uvm_bio.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.