Commit 04b6b4a5 authored Feb 26, 2016 by Boris Ostrovsky Committed by David Vrabel Mar 03, 2016

xen/x86: Zero out .bss for PV guests



ELF spec is unclear about whether .bss must me cleared by the loader.
Currently the domain builder does it when loading the guest but because
it is not (or rather may not be) guaranteed we should zero it out
explicitly.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

parent a4d7b75b

arch/x86/xen/xen-head.S

+9 −0

Original line number	Diff line number	Diff line
		@@ -38,6 +38,15 @@
		__INIT
		ENTRY(startup_xen)
		cld

		/* Clear .bss */
		xor %eax,%eax
		mov $__bss_start, %_ASM_DI
		mov $__bss_stop, %_ASM_CX
		sub %_ASM_DI, %_ASM_CX
		shr $__ASM_SEL(2, 3), %_ASM_CX
		rep __ASM_SIZE(stos)

		#ifdef CONFIG_X86_32
		mov %esi,xen_start_info
		mov $init_thread_union+THREAD_SIZE,%esp