[PATCH 4.19 205/361] xen/pvh: increase early stack size

From: Greg Kroah-Hartman
Date: Sun Nov 11 2018 - 19:01:18 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Roger Pau Monne <roger.pau@xxxxxxxxxx>

commit 7deecbda3026f5e2a8cc095d7ef7261a920efcf2 upstream.

While booting on an AMD EPYC box the stack canary would detect stack
overflows when using the current PVH early stack size (256). Switch to
using the value defined by BOOT_STACK_SIZE, which prevents the stack
overflow.

Cc: <stable@xxxxxxxxxxxxxxx> # 4.11
Signed-off-by: Roger Pau Monnà <roger.pau@xxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/xen/xen-pvh.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/xen/xen-pvh.S
+++ b/arch/x86/xen/xen-pvh.S
@@ -181,7 +181,7 @@ canary:
.fill 48, 1, 0

early_stack:
- .fill 256, 1, 0
+ .fill BOOT_STACK_SIZE, 1, 0
early_stack_end:

ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY,