Messages in this thread | | | Date | Sat, 31 Jan 2015 12:14:29 -0500 (EST) | From | Alan Stern <> | Subject | Re: [PATCH] pci-dma: Fix x86 dma_alloc_coherent to fully clear all pages returned |
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On Fri, 30 Jan 2015, Andi Kleen wrote:
> > We don't "need" any backward compatility, why not fix the broken drivers > > that are using memory outside of what they are asking for? That's not > > ok no matter what, right? > > How would you find them all? > > We don't even know which place in XHCI is the culprit here.
It shouldn't be too hard to find, expecially if the fault can easily be reproduced.
There are only about half a dozen calls to dma_alloc_coherent in the xhci-hcd driver. Just add 64 KB to the requested memory size in each of them. Then one-by-one (or using bisection) remove the extra size and see which spots trigger the fault.
Alan Stern
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