On 21 March 2018 at 22:29, Philippe Mathieu-Daudé <f4...@amsat.org> wrote: > On 03/20/2018 02:41 PM, Peter Maydell wrote: >> For debug exceptions due to breakpoints or the BKPT instruction which >> are taken to AArch32, the Fault Address Register is architecturally >> UNKNOWN. We were using that as license to simply not set >> env->exception.vaddress, but this isn't correct, because it will >> expose to the guest whatever old value was in that field when >> arm_cpu_do_interrupt_aarch32() writes it to the guest IFSR. That old >> value might be a FAR for a previous guest EL2 or secure exception, in >> which case we shouldn't show it to an EL1 or non-secure exception >> handler. It might also be a non-deterministic value, which is bad >> for record-and-replay. >> >> Clear env->exception.vaddress before taking breakpoint debug >> exceptions, to avoid this minor information leak. > > So this series is worth Cc'ing qemu-stable...?
I don't think so. This isn't a regression -- we've behaved this way ever since we introduced LPAE support, five years or so ago. In particular Linux doesn't care about it. thanks -- PMM
