On Mon, Sep 22, 2014 at 11:19:04AM +0100, Will Deacon wrote: > When returning from a debug exception taken from EL1, we unmask debug > exceptions after handling the exception. This is crucial for debug > exceptions taken from EL0, so that any kernel work on the ret_to_user > path can be debugged by kgdb. > > However, when returning back to EL1 the only thing left to do is to > restore the original register state before the exception return. If > single-step has been enabled by the debug exception handler, we will > get stuck in an infinite debug exception loop, since we will take the > step exception as soon as we unmask debug exceptions. > > This patch avoids unmasking debug exceptions on the debug exception > return path when the exception was taken from EL1. > > Cc: <stable@xxxxxxxxxxxxxxx> Does it work better if I add: Fixes: 2a2830703a23 (arm64: debug: avoid accessing mdscr_el1 on fault paths where possible) Cc: <stable@xxxxxxxxxxxxxxx> #3.16+ -- Catalin -- 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