lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 16 Oct 2017 12:14:46 +0100 From: Robin Murphy <robin.murphy@....com> To: Marian Mihailescu <marian.mihailescu@...laide.edu.au> Cc: Vladimir Murzin <vladimir.murzin@....com>, Randy Dunlap <rdunlap@...radead.org>, linux-kernel@...r.kernel.org, Bart Van Assche <bart.vanassche@...disk.com>, iommu@...ts.linux-foundation.org, Christoph Hellwig <hch@....de> Subject: Re: CONFIG_DMA_NOOP_OPS breaks ARM arch On 16/10/17 09:12, Vladimir Murzin wrote: > + Robin and Christoph > > On 16/10/17 06:27, Marian Mihailescu wrote: >> I am using 4.14-rc4 with a patch on top that includes >> arch/arm/include/asm/dma-mapping.h in a module. >> >> I have MMU enabled, so >> select DMA_NOOP_OPS if !MMU >> does nothing for me, and I get a compile error because dma_noop_ops is unknown. > > Can you post an error message here, please? > >> >> Maybe I should include linux/dma-mapping.h? That is the *only* dma-mapping header you should be referring to. Including the arch/*/asm/ version directly is just broken and asking for trouble. Robin. > Where to include? In your driver or what? > >> >> Thanks for the quick reply. > > with CONFIG_MMU compiler should optimise out dma_noop_ops in: > > return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_noop_ops; > > What toolchain are you using? > > Cheers > Vladimir > >> >> >> On Mon, Oct 16, 2017 at 2:28 PM, Randy Dunlap <rdunlap@...radead.org> wrote: >>> On 10/15/17 20:29, Randy Dunlap wrote: >>>> On 10/15/17 20:27, Randy Dunlap wrote: >>>>> On 10/15/17 19:27, Marian Mihailescu wrote: >>>>>> After commit 7844572c633964c864d9f32dc3f2a8ffe5d70371, dma_noop_ops >>>>>> are built only for architectures that use it. >>>>>> >>>>>> For ARM architecture, CONFIG_DMA_NOOP_OPS is not selected, and cannot >>>>>> be selected. >>> >>> What kernel version are you looking at? >>> I see that it is selected: >>> >>> --- a/arch/arm/Kconfig >>> +++ b/arch/arm/Kconfig >>> @@ -22,6 +22,7 @@ config ARM >>> select CLONE_BACKWARDS >>> select CPU_PM if (SUSPEND || CPU_IDLE) >>> select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS >>> + select DMA_NOOP_OPS if !MMU >>> select EDAC_SUPPORT >>> select EDAC_ATOMIC_SCRUB >>> select GENERIC_ALLOCATOR >>> >>> >>> That's in commit ID 1c51c429f30ea10428337f3a33c12059ba59f668 from May 24, 2017. >>> >>>>>> However, arch/arm/include/asm/dma-mapping.h is referencing dma_noop_ops: >>>>>> >>>>>> static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) >>>>>> { >>>>>> return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_noop_ops; >>>>>> } >>>>>> >>>>>> I will let a maintainer suggest the best resolution for this :) >>>>>> >>>>> >>>>> add Bart and iommu mailing list. >>>>> >>>> >>>> and add Vladimir. >>>> >>>> >>> >>> >>> -- >>> ~Randy >
Powered by blists - more mailing lists