From 8a3c4acc9907cfec9aae9f1bc251fbf50af6828e Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Tue, 27 Aug 2013 11:28:26 +0200 Subject: [PATCH] x86/boot: Explicitly clean pcpu stacks in debug builds 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 --- 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 ed3888d469..399541d19a 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 9f81c7ba62..8bfa151a40 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<