linux-kernel - [PATCH] xen/pvh: increase early stack size

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Date:   Tue, 9 Oct 2018 12:32:37 +0200
From:   Roger Pau Monne <roger.pau@...rix.com>
To:     <linux-kernel@...r.kernel.org>
CC:     Roger Pau Monne <roger.pau@...rix.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        <xen-devel@...ts.xenproject.org>
Subject: [PATCH] xen/pvh: increase early stack size

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.

Signed-off-by: Roger Pau Monné <roger.pau@...rix.com>
---
Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Cc: Juergen Gross <jgross@...e.com>
Cc: xen-devel@...ts.xenproject.org
---
 arch/x86/xen/xen-pvh.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
index ca2d3b2bf2af..58722a052f9c 100644
--- 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,
-- 
2.19.0