From: Vladimir Serbinenko <phcoder@gmail.com>
Date: Mon, 6 Feb 2017 23:42:43 +0000 (+0100)
Subject: xen: Fix handling of GRUB chainloading.
X-Git-Tag: 2.02-rc2~12
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a96fc409373fffda99e18a8438ddfc6bb787bc8;p=thirdparty%2Fgrub.git

xen: Fix handling of GRUB chainloading.

In case of GRUB we put remapper after domain pages and not at 0x0.
In this case we use max_addr to put remapper. Unfortunately we increment
max_addr as well in this case resulting in virt mapping mapping page
at old max_addr and trying to boot using new max_addr.

Closes 46014.
---

diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
index 51d1ddd37..3073f64d5 100644
--- a/grub-core/loader/i386/xen.c
+++ b/grub-core/loader/i386/xen.c
@@ -419,8 +419,6 @@ grub_xen_pt_alloc (void)
       try_virt_end = ALIGN_UP (xen_state.xen_inf.virt_base +
 			       page2offset (nr_need_pages) +
 			       ADDITIONAL_SIZE + STACK_SIZE, ALIGN_SIZE);
-      if (!xen_state.xen_inf.virt_base)
-	try_virt_end += PAGE_SIZE;
 
       err = get_pgtable_size (xen_state.xen_inf.virt_base, try_virt_end,
 			      nr_info_pages);
@@ -433,7 +431,7 @@ grub_xen_pt_alloc (void)
       if (xen_state.xen_inf.virt_base)
 	err = get_pgtable_size (0, PAGE_SIZE, nr_need_pages);
       else
-	err = get_pgtable_size (try_virt_end - PAGE_SIZE, try_virt_end,
+	err = get_pgtable_size (try_virt_end, try_virt_end + PAGE_SIZE,
 				nr_need_pages);
       if (err)
 	return err;