From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20081127103136.719281319@de.ibm.com> References: <20081127103020.528516828@de.ibm.com> Date: Thu, 27 Nov 2008 11:30:52 +0100 From: Martin Schwidefsky Subject: [patch 32/60] Remove initial kernel stack backchain initialization. Content-Disposition: inline; filename=131-clear-backchain.diff Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: Heiko Carstens , Martin Schwidefsky List-ID: From: Heiko Carstens Early init code clears the backchain of the initial kernel stack frame. This is not necessary since it is pre initialized with zeros. Plus it was broken on 64 bit since it cleared only four of eight bytes. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/head31.S | 1 - arch/s390/kernel/head64.S | 1 - 2 files changed, 2 deletions(-) Index: quilt-2.6/arch/s390/kernel/head31.S =================================================================== --- quilt-2.6.orig/arch/s390/kernel/head31.S +++ quilt-2.6/arch/s390/kernel/head31.S @@ -29,7 +29,6 @@ startup_continue: ahi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE st %r15,__LC_KERNEL_STACK # set end of kernel stack ahi %r15,-96 - xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain # # Save ipl parameters, clear bss memory, initialize storage key for kernel pages, # and create a kernel NSS if the SAVESYS= parm is defined Index: quilt-2.6/arch/s390/kernel/head64.S =================================================================== --- quilt-2.6.orig/arch/s390/kernel/head64.S +++ quilt-2.6/arch/s390/kernel/head64.S @@ -96,7 +96,6 @@ startup_continue: aghi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE stg %r15,__LC_KERNEL_STACK # set end of kernel stack aghi %r15,-160 - xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain # # Save ipl parameters, clear bss memory, initialize storage key for kernel pages, # and create a kernel NSS if the SAVESYS= parm is defined -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.