From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from am1outboundpool.messaging.microsoft.com (am1ehsobe003.messaging.microsoft.com [213.199.154.206]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Microsoft Secure Server Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 90FBA2C0102 for ; Tue, 17 Jul 2012 05:07:34 +1000 (EST) From: Stuart Yoder To: Subject: [PATCH] powerpc: set stack limit properly in crit_transfer_to_handler Date: Mon, 16 Jul 2012 14:06:48 -0500 Message-ID: <1342465608-20596-1-git-send-email-stuart.yoder@freescale.com> MIME-Version: 1.0 Content-Type: text/plain Cc: sfr@canb.auug.org.au, Stuart Yoder , paulus@samba.org, linuxppc-dev@lists.ozlabs.org, agraf@suse.de List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Stuart Yoder without setting the stack limit like this there is the possibility of stack overflow which corrupts the thread info but is not detected by stack overflow detection Signed-off-by: Stuart Yoder --- arch/powerpc/kernel/entry_32.S | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 5207d5a..ead5016 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -89,10 +89,14 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,_SRR1(r11) + /* set the stack limit to the current stack + * and set the limit to protect the thread_info + * struct + */ mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) - CURRENT_THREAD_INFO(r0, r1) + rlwimi r0,r1,0,0,(31-THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -109,10 +113,14 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,crit_srr1@l(0) + /* set the stack limit to the current stack + * and set the limit to protect the thread_info + * struct + */ mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) - CURRENT_THREAD_INFO(r0, r1) + rlwimi r0,r1,0,0,(31-THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ #endif -- 1.7.3.4