On 06/06/17 21:09, Christoffer Dall wrote: > On Tue, Jun 06, 2017 at 07:08:34PM +0100, Marc Zyngier wrote: >> We currently have the SCTLR_EL2.A bit set, trapping unaligned accesses >> at EL2, but we're not really prepared to deal with it. So far, this >> has been unnoticed, until GCC 7 started emitting those (in particular >> 64bit writes on a 32bit boundary). >> >> Since the rest of the kernel is pretty happy about that, let's follow >> its example and set SCTLR_EL2.A to zero. Modern CPUs don't really >> care. > > Why do we set the A flag via SCTLR_ELx_FLAGS in the first place, only to > drop that flag later on for both EL1 and EL2 ? That flag is always cleared at EL1, never set. Actually, only EL2 uses that macro to *set* flags. An alternative would be to do away with the macro and use the individual flags, like the 32bit side does. What do you think? M. -- Jazz is not dead. It just smells funny...
