linux-kernel - Re: [PATCH v3] Fix dma_mapping

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20081130001152F.fujita.tomonori@lab.ntt.co.jp>
Date:	Sun, 30 Nov 2008 00:13:03 +0900
From:	FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>
To:	tsbogend@...ha.franken.de, mingo@...e.hu
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] Fix dma_mapping_error for 32bit x86

On Sat, 29 Nov 2008 13:46:27 +0100 (CET)
Thomas Bogendoerfer <tsbogend@...ha.franken.de> wrote:

> Devices like b44 ethernet can't dma from addresses above 1GB. The driver
> handles this cases by falling back to GFP_DMA allocation. But for detecting
> the problem it needs to get an indication from dma_mapping_error.
> The bug is triggered by using a VMSPLIT option of 2G/2G.
> 
> Signed-off-by: Thomas Bogendoerfer <tsbogend@...ha.franken.de>
> ---
> 
> 
> diff -ru orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h linux-2.6.27.4/include/asm-x86/dma-mapping.h
> --- orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h	2008-10-26 00:05:07.000000000 +0200
> +++ linux-2.6.27.4/include/asm-x86/dma-mapping.h	2008-10-26 11:06:14.000000000 +0100
> @@ -74,15 +74,13 @@
>  /* Make sure we keep the same behaviour */
>  static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
>  {
> -#ifdef CONFIG_X86_32
> -	return 0;
> -#else
> +#ifdef CONFIG_X86_64
>  	struct dma_mapping_ops *ops = get_dma_ops(dev);
>  	if (ops->mapping_error)
>  		return ops->mapping_error(dev, dma_addr);
>  
> -	return (dma_addr == bad_dma_address);
>  #endif
> +	return (dma_addr == bad_dma_address);
>  }

Surely, 2.6.27.4 needs this fix (and all the stable trees need this
too, I think).

This can't be cleanly applied to the current git (dma-mapping.h was
moved). How about just removing the ifdef? I think that it's clean a
bit.


diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 7f225a4..dc22c07 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -71,15 +71,11 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
 /* Make sure we keep the same behaviour */
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
-#ifdef CONFIG_X86_32
-	return 0;
-#else
 	struct dma_mapping_ops *ops = get_dma_ops(dev);
 	if (ops->mapping_error)
 		return ops->mapping_error(dev, dma_addr);
 
 	return (dma_addr == bad_dma_address);
-#endif
 }
 
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/