On Thu, Apr 25, 2013 at 07:00:37PM +0200, Andi Kleen wrote: > > Traping the read deals with the first. The second shouldn't be a problem since > > we generally only allow kernel info for CAP_ADMIN; if we don't already for LBR > > that needs to be fixed separately. > > Where is that check? I don't see it. Then that might need fixing. > Also remember that precise == 2 can enable LBR implicitly. Sure.. but it doesn't need the filter stuff. Now I completely forgot if it will actually still use the filter muck.. /me goes check I think intel_pmu_lbr_filter() will typically bail on the X86_BR_ALL test for PEBS fixup, it might only end up in the filter code if precise_br_compat() finds another LBR user compatible with the fixup. > > That only leaves the third.. can we descern MMIO maps from the kernel page tables? > > In theory you could use some bits in the PTE for vmalloc, but it would need quite a > few changes. > > Also there may be corner cases where MMIO is in the direct mapping or in > the kernel mapping. Hrmm... do we keep track of the MMIO regions somewhere at all? -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html