xen/pvh: increase early stack size

BugLink: https://bugs.launchpad.net/bugs/1836802
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@vger.kernel.org> # 4.11
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
index 1ed71047cc49eaf6e10994fd6de3aa4d04fc21e7..882c2c02d91779c07a9ce2b42fafd841491161ec 100644 (file)
--- a/arch/x86/xen/xen-pvh.S
+++ b/arch/x86/xen/xen-pvh.S
@@ -180,7 +180,7 @@ 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,