From patchwork Tue Oct 7 16:10:03 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Boyer X-Patchwork-Id: 3187 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 19BBCDE1AA for ; Wed, 8 Oct 2008 03:11:57 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from mail-gx0-f21.google.com (mail-gx0-f21.google.com [209.85.217.21]) by ozlabs.org (Postfix) with ESMTP id B9812DDEFC for ; Wed, 8 Oct 2008 03:11:26 +1100 (EST) Received: by gxk14 with SMTP id 14so9248248gxk.9 for ; Tue, 07 Oct 2008 09:11:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :message-id:mime-version:content-type:content-disposition:user-agent :sender; bh=qfUtlDd9etUsGz2r/l8sfn8YbhnuRWEwYtlqogEsc8o=; b=ZDV4u/FMzNq+UBXsVTi2iBiHSaubMvUWQ3VkEIdoOT3Ro9nvdoPoGXyWXUVi7kuFLq IQzRpU12BwH9yyrHodz8UTwTjNZV5TFPmLJiyaHDmguJzb7BoVYdd7wKFBLezltnej/G juhaaGhuUGUuN94HnV6iet3PDvsV/dOsKXQqw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent:sender; b=vyAgRxW7Q4MFNXDxopniA6aQfrcx5J2Kx/Bz0wVRb4fecDO8O/oX6GeBFg+ql7WiZ4 oWUQmerMMoCsMEWi6sbjXLfxO5QWIcRtNzgjHkCqQaGIF2Fgu9LjGnQekghthzJwWrYH CYdnB8y9nTYh61/cZJwBQ/2XIHeNq4vgrF9Ys= Received: by 10.100.212.6 with SMTP id k6mr54456ang.0.1223395885342; Tue, 07 Oct 2008 09:11:25 -0700 (PDT) Received: from yoda.jdub.homelinux.org (24-247-237-59.dhcp.aldl.mi.charter.com [24.247.237.59]) by mx.google.com with ESMTPS id p31sm13358256qbp.18.2008.10.07.09.11.23 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 07 Oct 2008 09:11:24 -0700 (PDT) Date: Tue, 7 Oct 2008 12:10:03 -0400 From: Josh Boyer To: paulus@samba.org, benh@kernel.crashing.org Subject: [PATCH] powerpc: Fix error path in kernel_thread function Message-ID: <20081007161003.GA5727@yoda.jdub.homelinux.org> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Cc: linuxppc-dev@ozlabs.org, jpoimboe@us.ibm.com X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org From: Josh Poimboeuf The powerpc 32-bit and 64-bit kernel_thread functions don't properly propagate errors being returned by the clone syscall. (In the case of error, the syscall exit code returns a positive errno in r3 and sets the CR0[SO] bit.) This patch fixes that by negating r3 if CR0[SO] is set after the syscall. Signed-off-by: Josh Poimboeuf Signed-off-by: Josh Boyer Acked-by: Paul Mackerras --- arch/powerpc/kernel/misc_32.S | 8 +++++--- arch/powerpc/kernel/misc_64.S | 8 +++++--- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 7a6dfbc..1fe9f62 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -846,8 +846,10 @@ _GLOBAL(kernel_thread) li r4,0 /* new sp (unused) */ li r0,__NR_clone sc - cmpwi 0,r3,0 /* parent or child? */ - bne 1f /* return if parent */ + bns+ 1f /* did system call indicate error? */ + neg r3,r3 /* if so, make return code negative */ +1: cmpwi 0,r3,0 /* parent or child? */ + bne 2f /* return if parent */ li r0,0 /* make top-level stack frame */ stwu r0,-16(r1) mtlr r30 /* fn addr in lr */ @@ -857,7 +859,7 @@ _GLOBAL(kernel_thread) li r0,__NR_exit /* exit if function returns */ li r3,0 sc -1: lwz r30,8(r1) +2: lwz r30,8(r1) lwz r31,12(r1) addi r1,r1,16 blr diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 4dd70cf..3053fe5 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -426,8 +426,10 @@ _GLOBAL(kernel_thread) li r4,0 /* new sp (unused) */ li r0,__NR_clone sc - cmpdi 0,r3,0 /* parent or child? */ - bne 1f /* return if parent */ + bns+ 1f /* did system call indicate error? */ + neg r3,r3 /* if so, make return code negative */ +1: cmpdi 0,r3,0 /* parent or child? */ + bne 2f /* return if parent */ li r0,0 stdu r0,-STACK_FRAME_OVERHEAD(r1) ld r2,8(r29) @@ -438,7 +440,7 @@ _GLOBAL(kernel_thread) li r0,__NR_exit /* exit after child exits */ li r3,0 sc -1: addi r1,r1,STACK_FRAME_OVERHEAD +2: addi r1,r1,STACK_FRAME_OVERHEAD ld r29,-24(r1) ld r30,-16(r1) blr