PR/52662 CVS commit: src/sys/arch/amd64/amd64

["Maxime Villard" <maxv%netbsd.org@localhost>]

The following reply was made to PR port-xen/52662; it has been noted by GNATS.

From: "Maxime Villard" <maxv%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/52662 CVS commit: src/sys/arch/amd64/amd64
Date: Sat, 28 Oct 2017 20:06:31 +0000

 Module Name:	src
 Committed By:	maxv
 Date:		Sat Oct 28 20:06:31 UTC 2017
 
 Modified Files:
 	src/sys/arch/amd64/amd64: locore.S
 
 Log Message:
 It appears that Xen remaps the userland %cs to 0xE033. So add it to the
 checklist. Otherwise we're going through Luexit32: %fs gets reloaded,
 which sets the FS.base to NULL, which will cause the thread to page-fault
 next time it accesses its TLS (as seen in PR/52662).
 
 This fix is not very clean, and it would be nice to understand why Xen
 remaps %cs. But I'm committing it now anyway, so that people can test.
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.138 -r1.139 src/sys/arch/amd64/amd64/locore.S
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.