From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: [Patch v2] x86/boot: Explicitly clean pcpu stacks in debug builds Date: Mon, 26 Aug 2013 12:10:04 +0100 Message-ID: <1377515404-21423-1-git-send-email-andrew.cooper3@citrix.com> References: <520E0E1202000078000EC84D@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <520E0E1202000078000EC84D@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Xen-devel Cc: Andrew Cooper , Keir Fraser , Jan Beulich List-Id: xen-devel@lists.xenproject.org This reduces confusion when looking at a hexdump of the pcpu stacks and wondering were on earth some of the junk was coming from. Also leave some grep fodder for finding where the BSP switches stack (because it took me far longer to find than I care to admit to) Signed-off-by: Andrew Cooper CC: Keir Fraser CC: Jan Beulich --- Changes since v1: Brackets around shift operation, and correct the calculation for cpu0_stack, both noticed by Jan Beulich. --- xen/arch/x86/boot/x86_64.S | 9 +++++++++ xen/arch/x86/smpboot.c | 4 ++++ 2 files changed, 13 insertions(+) diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S index ed3888d..399541d 100644 --- a/xen/arch/x86/boot/x86_64.S +++ b/xen/arch/x86/boot/x86_64.S @@ -13,6 +13,15 @@ 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 9f81c7b..f6b42f5 100644 --- a/xen/arch/x86/smpboot.c +++ b/xen/arch/x86/smpboot.c @@ -659,6 +659,10 @@ 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<