svn commit: r364517 - in head: sys/sys usr.bin/elfctl

[Konstantin Belousov]

Author: kib
Date: Sun Aug 23 19:47:27 2020
New Revision: 364517
URL: https://svnweb.freebsd.org/changeset/base/364517

Log:
  Reserve FreeBSD ELF feature control bit LA48 to control VA layout on amd64.
  
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  Differential revision:	https://reviews.freebsd.org/D25273

Modified:
  head/sys/sys/elf_common.h
  head/usr.bin/elfctl/elfctl.c

Modified: head/sys/sys/elf_common.h
==============================================================================
--- head/sys/sys/elf_common.h	Sun Aug 23 19:47:10 2020	(r364516)
+++ head/sys/sys/elf_common.h	Sun Aug 23 19:47:27 2020	(r364517)
@@ -796,6 +796,7 @@ typedef struct {
 #define	NT_FREEBSD_FCTL_PROTMAX_DISABLE	0x00000002
 #define	NT_FREEBSD_FCTL_STKGAP_DISABLE	0x00000004
 #define	NT_FREEBSD_FCTL_WXNEEDED	0x00000008
+#define	NT_FREEBSD_FCTL_LA48		0x00000010
 
 /* Values for n_type.  Used in core files. */
 #define	NT_PRSTATUS	1	/* Process status. */

Modified: head/usr.bin/elfctl/elfctl.c
==============================================================================
--- head/usr.bin/elfctl/elfctl.c	Sun Aug 23 19:47:10 2020	(r364516)
+++ head/usr.bin/elfctl/elfctl.c	Sun Aug 23 19:47:27 2020	(r364517)
@@ -67,6 +67,7 @@ static struct ControlFeatures featurelist[] = {
 	    "Disable implicit PROT_MAX" },
 	{ "stackgap",	NT_FREEBSD_FCTL_STKGAP_DISABLE, "Disable stack gap" },
 	{ "wxneeded",	NT_FREEBSD_FCTL_WXNEEDED, "Requires W+X mappings" },
+	{ "la48",	NT_FREEBSD_FCTL_LA48, "amd64: Limit user VA to 48bit" },
 };
 
 static struct option long_opts[] = {