Messages in this thread |  | | Date | Mon, 24 Feb 2014 09:52:11 -0800 | From | "H. Peter Anvin" <> | Subject | Re: perf_fuzzer compiled for x32 causes reboot |
| |
On 02/24/2014 09:25 AM, Peter Zijlstra wrote: >> >> What is likely happening is the user page fault is triggering >> code to do a "perf_callchain" dump, which is calling copy_from_user_nmi() >> which calls copy_user_generic_string() which is somehow getting the user >> RBP in the RDI register somehow? > > So that code very much relies on the 'recursive' NMI/iret magic from > Steve, patch 3f3c8b8c4b2a3 (and assorted fixes later). > > If CR2 is getting corrupted; 7fbb98c5cb075 seems relevant. > > Peter, does x32 have a slightly different ABI/calling convention that > would make any of these patches just slightly 'off'? >
As long as we're talking kernel code, x32 isn't even involved (we do not support compiling the kernel as x32 and most likely never will.)
-hpa
|  |