From mboxrd@z Thu Jan 1 00:00:00 1970 From: walter harms Date: Sun, 02 Dec 2012 15:33:59 +0000 Subject: Re: [patch v2] x86, UV: integer wrap bug in uv_hub_ipi_value() Message-Id: <50BB74E7.9060306@bfs.de> List-Id: References: <20121202104438.GD16078@elgon.mountain> In-Reply-To: <20121202104438.GD16078@elgon.mountain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Russ Anderson , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Am 02.12.2012 11:44, schrieb Dan Carpenter: > This is a static checker fix. The problem is that we store the bits > from "uv_apicid_hibits" into "apicid" (the high 16 bits) but then we > shift it 16 bit to the left. "apicid" is an int so it wraps and we lose > them. > > Signed-off-by: Dan Carpenter > --- > v2: Style fix. Don't use ulong. > > I don't have this hardware so I can't test it. There may also be other > bugs which this patch does not addressed. These files are only compiled > on x86_64 and "unsigned long" is used throughout to mean 64 bits. > > diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h > index 21f7385..e7a83d5 100644 > --- a/arch/x86/include/asm/uv/uv_hub.h > +++ b/arch/x86/include/asm/uv/uv_hub.h > @@ -577,7 +577,7 @@ static unsigned long uv_hub_ipi_value(int apicid, int vector, int mode) > { > apicid |= uv_apicid_hibits; > return (1UL << UVH_IPI_INT_SEND_SHFT) | > - ((apicid) << UVH_IPI_INT_APIC_ID_SHFT) | > + ((unsigned long)apicid << UVH_IPI_INT_APIC_ID_SHFT) | > (mode << UVH_IPI_INT_DELIVERY_MODE_SHFT) | > (vector << UVH_IPI_INT_VECTOR_SHFT); > } > diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c > index 8cfade9..6d93b2f 100644 > --- a/arch/x86/kernel/apic/x2apic_uv_x.c > +++ b/arch/x86/kernel/apic/x2apic_uv_x.c > @@ -194,13 +194,13 @@ static int __cpuinit uv_wakeup_secondary(int phys_apicid, unsigned long start_ri > pnode = uv_apicid_to_pnode(phys_apicid); > phys_apicid |= uv_apicid_hibits; > val = (1UL << UVH_IPI_INT_SEND_SHFT) | > - (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > + ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) | > APIC_DM_INIT; > uv_write_global_mmr64(pnode, UVH_IPI_INT, val); > > val = (1UL << UVH_IPI_INT_SEND_SHFT) | > - (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > + ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) | > APIC_DM_STARTUP; > uv_write_global_mmr64(pnode, UVH_IPI_INT, val); making this more readable is hard but what is about: val=(1UL << UVH_IPI_INT_SEND_SHFT) | ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12); uv_write_global_mmr64(pnode, UVH_IPI_INT, val|APIC_DM_INIT); uv_write_global_mmr64(pnode, UVH_IPI_INT, val|APIC_DM_STARTUP); just my 2 cents, re wh > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753941Ab2LBPeF (ORCPT ); Sun, 2 Dec 2012 10:34:05 -0500 Received: from mx01.sz.bfs.de ([194.94.69.103]:38642 "EHLO mx01.sz.bfs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752599Ab2LBPeD (ORCPT ); Sun, 2 Dec 2012 10:34:03 -0500 Message-ID: <50BB74E7.9060306@bfs.de> Date: Sun, 02 Dec 2012 16:33:59 +0100 From: walter harms Reply-To: wharms@bfs.de User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; de; rv:1.9.1.16) Gecko/20101125 SUSE/3.0.11 Thunderbird/3.0.11 MIME-Version: 1.0 To: Dan Carpenter CC: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Russ Anderson , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [patch v2] x86, UV: integer wrap bug in uv_hub_ipi_value() References: <20121202104438.GD16078@elgon.mountain> In-Reply-To: <20121202104438.GD16078@elgon.mountain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 02.12.2012 11:44, schrieb Dan Carpenter: > This is a static checker fix. The problem is that we store the bits > from "uv_apicid_hibits" into "apicid" (the high 16 bits) but then we > shift it 16 bit to the left. "apicid" is an int so it wraps and we lose > them. > > Signed-off-by: Dan Carpenter > --- > v2: Style fix. Don't use ulong. > > I don't have this hardware so I can't test it. There may also be other > bugs which this patch does not addressed. These files are only compiled > on x86_64 and "unsigned long" is used throughout to mean 64 bits. > > diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h > index 21f7385..e7a83d5 100644 > --- a/arch/x86/include/asm/uv/uv_hub.h > +++ b/arch/x86/include/asm/uv/uv_hub.h > @@ -577,7 +577,7 @@ static unsigned long uv_hub_ipi_value(int apicid, int vector, int mode) > { > apicid |= uv_apicid_hibits; > return (1UL << UVH_IPI_INT_SEND_SHFT) | > - ((apicid) << UVH_IPI_INT_APIC_ID_SHFT) | > + ((unsigned long)apicid << UVH_IPI_INT_APIC_ID_SHFT) | > (mode << UVH_IPI_INT_DELIVERY_MODE_SHFT) | > (vector << UVH_IPI_INT_VECTOR_SHFT); > } > diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c > index 8cfade9..6d93b2f 100644 > --- a/arch/x86/kernel/apic/x2apic_uv_x.c > +++ b/arch/x86/kernel/apic/x2apic_uv_x.c > @@ -194,13 +194,13 @@ static int __cpuinit uv_wakeup_secondary(int phys_apicid, unsigned long start_ri > pnode = uv_apicid_to_pnode(phys_apicid); > phys_apicid |= uv_apicid_hibits; > val = (1UL << UVH_IPI_INT_SEND_SHFT) | > - (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > + ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) | > APIC_DM_INIT; > uv_write_global_mmr64(pnode, UVH_IPI_INT, val); > > val = (1UL << UVH_IPI_INT_SEND_SHFT) | > - (phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > + ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | > ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12) | > APIC_DM_STARTUP; > uv_write_global_mmr64(pnode, UVH_IPI_INT, val); making this more readable is hard but what is about: val=(1UL << UVH_IPI_INT_SEND_SHFT) | ((unsigned long)phys_apicid << UVH_IPI_INT_APIC_ID_SHFT) | ((start_rip << UVH_IPI_INT_VECTOR_SHFT) >> 12); uv_write_global_mmr64(pnode, UVH_IPI_INT, val|APIC_DM_INIT); uv_write_global_mmr64(pnode, UVH_IPI_INT, val|APIC_DM_STARTUP); just my 2 cents, re wh > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >