From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Lameter Subject: Re: [kernel-hardening] [PATCH 09/38] usercopy: Mark kmalloc caches as usercopy caches Date: Mon, 3 Feb 2020 17:20:02 +0000 (UTC) Message-ID: References: <202001271519.AA6ADEACF0@keescook> <5861936c-1fe1-4c44-d012-26efa0c8b6e7@de.ibm.com> <202001281457.FA11CC313A@keescook> <6844ea47-8e0e-4fb7-d86f-68046995a749@de.ibm.com> <20200129170939.GA4277@infradead.org> <771c5511-c5ab-3dd1-d938-5dbc40396daa@de.ibm.com> <202001300945.7D465B5F5@keescook> <202002010952.ACDA7A81@keescook> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <202002010952.ACDA7A81@keescook> Sender: linux-kernel-owner@vger.kernel.org To: Kees Cook Cc: Jann Horn , Christian Borntraeger , Christoph Hellwig , Jiri Slaby , Julian Wiedmann , Ursula Braun , Alexander Viro , kernel list , David Windsor , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Linux-MM , linux-xfs@vger.kernel.org, Linus Torvalds , Andy Lutomirski , "David S. Miller" , Laura Abbott , Mark Rutland List-Id: linux-arch.vger.kernel.org On Sat, 1 Feb 2020, Kees Cook wrote: > > I can't find where the address limit for dma-kmalloc is implemented. include/linux/mmzones.h enum zone_type { /* * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able * to DMA to all of the addressable memory (ZONE_NORMAL). * On architectures where this area covers the whole 32 bit address * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller * DMA addressing constraints. This distinction is important as a 32bit * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit * platforms may need both zones as they support peripherals with * different DMA addressing limitations. * * Some examples: * * - i386 and x86_64 have a fixed 16M ZONE_DMA and ZONE_DMA32 for the * rest of the lower 4G. * * - arm only uses ZONE_DMA, the size, up to 4G, may vary depending on * the specific device. * * - arm64 has a fixed 1G ZONE_DMA and ZONE_DMA32 for the rest of the * lower 4G. * * - powerpc only uses ZONE_DMA, the size, up to 2G, may vary * depending on the specific device. * * - s390 uses ZONE_DMA fixed to the lower 2G. * * - ia64 and riscv only use ZONE_DMA32. * * - parisc uses neither. */ #ifdef CONFIG_ZONE_DMA ZONE_DMA, #endif #ifdef CONFIG_ZONE_DMA32 ZONE_DMA32, #endif /* * Normal addressable memory is in ZONE_NORMAL. DMA operations can be * performed on pages in ZONE_NORMAL if the DMA devices support * transfers to all addressable memory. */ ZONE_NORMAL, #ifdef CONFIG_HIGHMEM /* * A memory area that is only addressable by the kernel through * mapping portions into its own address space. This is for example * used by i386 to allow the kernel to address the memory beyond * 900MB. The kernel will set up special mappings (page * table entries on i386) for each page that the kernel needs to * access. */ ZONE_HIGHMEM, #endif ZONE_MOVABLE, #ifdef CONFIG_ZONE_DEVICE ZONE_DEVICE, #endif __MAX_NR_ZONES }; From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 3 Feb 2020 17:20:02 +0000 (UTC) From: Christopher Lameter Subject: Re: [kernel-hardening] [PATCH 09/38] usercopy: Mark kmalloc caches as usercopy caches In-Reply-To: <202002010952.ACDA7A81@keescook> Message-ID: References: <202001271519.AA6ADEACF0@keescook> <5861936c-1fe1-4c44-d012-26efa0c8b6e7@de.ibm.com> <202001281457.FA11CC313A@keescook> <6844ea47-8e0e-4fb7-d86f-68046995a749@de.ibm.com> <20200129170939.GA4277@infradead.org> <771c5511-c5ab-3dd1-d938-5dbc40396daa@de.ibm.com> <202001300945.7D465B5F5@keescook> <202002010952.ACDA7A81@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Kees Cook Cc: Jann Horn , Christian Borntraeger , Christoph Hellwig , Jiri Slaby , Julian Wiedmann , Ursula Braun , Alexander Viro , kernel list , David Windsor , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Linux-MM , linux-xfs@vger.kernel.org, Linus Torvalds , Andy Lutomirski , "David S. Miller" , Laura Abbott , Mark Rutland , "Martin K. Petersen" , Paolo Bonzini , Christoffer Dall , Dave Kleikamp , Jan Kara , Luis de Bethencourt , Marc Zyngier , Rik van Riel , Matthew Garrett , linux-fsdevel , linux-arch , Network Development , Kernel Hardening , Vlastimil Babka , Michal Kubecek List-ID: Message-ID: <20200203172002.NGK_Gn3yJ94U2g_JRQSKP3G8FadbFGWwcvciM8rggic@z> On Sat, 1 Feb 2020, Kees Cook wrote: > > I can't find where the address limit for dma-kmalloc is implemented. include/linux/mmzones.h enum zone_type { /* * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able * to DMA to all of the addressable memory (ZONE_NORMAL). * On architectures where this area covers the whole 32 bit address * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller * DMA addressing constraints. This distinction is important as a 32bit * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit * platforms may need both zones as they support peripherals with * different DMA addressing limitations. * * Some examples: * * - i386 and x86_64 have a fixed 16M ZONE_DMA and ZONE_DMA32 for the * rest of the lower 4G. * * - arm only uses ZONE_DMA, the size, up to 4G, may vary depending on * the specific device. * * - arm64 has a fixed 1G ZONE_DMA and ZONE_DMA32 for the rest of the * lower 4G. * * - powerpc only uses ZONE_DMA, the size, up to 2G, may vary * depending on the specific device. * * - s390 uses ZONE_DMA fixed to the lower 2G. * * - ia64 and riscv only use ZONE_DMA32. * * - parisc uses neither. */ #ifdef CONFIG_ZONE_DMA ZONE_DMA, #endif #ifdef CONFIG_ZONE_DMA32 ZONE_DMA32, #endif /* * Normal addressable memory is in ZONE_NORMAL. DMA operations can be * performed on pages in ZONE_NORMAL if the DMA devices support * transfers to all addressable memory. */ ZONE_NORMAL, #ifdef CONFIG_HIGHMEM /* * A memory area that is only addressable by the kernel through * mapping portions into its own address space. This is for example * used by i386 to allow the kernel to address the memory beyond * 900MB. The kernel will set up special mappings (page * table entries on i386) for each page that the kernel needs to * access. */ ZONE_HIGHMEM, #endif ZONE_MOVABLE, #ifdef CONFIG_ZONE_DEVICE ZONE_DEVICE, #endif __MAX_NR_ZONES };