linux-kernel - Re: [PATCH] USB: use stack allocation for struct usb

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:  <494065F6.3010602@shaw.ca>
Date:	Wed, 10 Dec 2008 18:59:34 -0600
From:	Robert Hancock <hancockr@...w.ca>
To:	linux-kernel@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org
Subject:  Re: [PATCH] USB: use stack allocation for struct usb_ctrlrequest

Wu Fengguang wrote:
>> In many cases there is no problem to DMA high memory. If you happen to 
>> be working with a device that does have problems with full 32 bit 
>> addresses then GFP_DMA would be the right flag, not GFP_NOIO.
> 
> For 64bit systems, we can easily go beyond 4GB physical memory.
> So at least we should add GFP_DMA32 in addition to GFP_NOIO?

No. The DMA mapping API handles either setting up the IOMMU or doing 
software bounce buffering to handle the DMA transfer regardless of where 
the memory is located, so drivers don't need to mess with GFP_DMA32.

--
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/