From e15c09f90c6629ef36bf6b4d5534dfc3b0b3de01 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 27 Aug 2013 15:13:20 +0200
Subject: [PATCH] Revert "x86/boot: Explicitly clean pcpu stacks in debug
 builds"

This reverts commit 8a3c4acc9907cfec9aae9f1bc251fbf50af6828e.
It's reportedly broken.
---
 xen/arch/x86/boot/x86_64.S | 9 ---------
 xen/arch/x86/smpboot.c     | 4 ----
 2 files changed, 13 deletions(-)

diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S
index 399541d19a..ed3888d469 100644
--- a/xen/arch/x86/boot/x86_64.S
+++ b/xen/arch/x86/boot/x86_64.S
@@ -13,15 +13,6 @@
         mov     mmu_cr4_features(%rip),%rcx
         mov     %rcx,%cr4
 
-#ifndef NDEBUG
-        /* Clean stack. */
-        mov     stack_start(%rip),%rdi
-        mov     $(STACK_SIZE / 8),%rcx
-        xor     %eax,%eax
-        rep stosq
-#endif
-
-        /* Switch to cpu0_stack. */
         mov     stack_start(%rip),%rsp
         or      $(STACK_SIZE-CPUINFO_sizeof),%rsp
 
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 8bfa151a40..9f81c7ba62 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -659,10 +659,6 @@ static int cpu_smpboot_alloc(unsigned int cpu)
     stack_base[cpu] = alloc_xenheap_pages(STACK_ORDER, 0);
     if ( stack_base[cpu] == NULL )
         goto oom;
-#ifndef NDEBUG
-    for ( order = 0 ; order < (1<<STACK_ORDER); ++order )
-        clear_page(stack_base[cpu] + order * PAGE_SIZE);
-#endif
     memguard_guard_stack(stack_base[cpu]);
 
     order = get_order_from_pages(NR_RESERVED_GDT_PAGES);
-- 
2.30.2