Messages in this thread | | | Date | Mon, 19 Mar 2018 09:37:14 -0700 | From | Jacob Pan <> | Subject | Re: [PATCH v7 0/5] Add Intel IOMMU debugfs support |
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On Thu, 15 Mar 2018 14:18:54 +0100 Joerg Roedel <joro@8bytes.org> wrote:
> On Thu, Feb 15, 2018 at 08:38:11AM -0800, Jacob Pan wrote: > > Just wondering if your concern is on the implementation or the > > debugfs idea in general. Perhaps have some common IOMMU debugfs? > > My concern mainly is that we add interfaces which reveal > potentially security relevant information I don;t think security is any worse than existing kernel page table in debugfs. i.e. /sys/kernel/debug/page_tables This is a debug feature. > to user-space and that tools > come up using it so that this also becomes kABI and we can't easily > change it anymore and this whole stuff turns into a maintence > nightmare. > Agreed, perhaps we can address that by only dumping user readable data which avoid having a parser tool that relies on stable kABI?
> So that is definitly not something I'd like to see enabled in the > distros, and its better to avoid it at all and search for better ways > to debug upcoming issues. > We can make it "def_bool n" so only used by advanced customers who can recompile kernel. > BPF tracers and tracing in general comes to mind here... > my concern is that tracing is suitable for dynamic debugging, but these context info are mostly static. Perhaps I am missing some tracing features.
Thanks,
Jacob > > Joerg >
[Jacob Pan]
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