From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (bilbo.ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zh7cf1xsrzF12y for ; Wed, 14 Feb 2018 16:43:46 +1100 (AEDT) In-Reply-To: <20180208091838.27992-1-npiggin@gmail.com> To: Nicholas Piggin , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Cc: Sukadev Bhattiprolu , Nicholas Piggin Subject: Re: powerpc/vas: do not set uses_vas for kernel windows Message-Id: <3zh7cf17qqz9t3F@ozlabs.org> Date: Wed, 14 Feb 2018 16:43:46 +1100 (AEDT) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2018-02-08 at 09:18:38 UTC, Nicholas Piggin wrote: > cp_abort is only required or user windows, because kernel context > must not be preempted between a copy/paste pair. > > Without this patch, the init task gets used_vas set when it runs > the nx842_powernv_init initcall, which opens windows for kernel > usage. > > used_vas is then never cleared anywhere, so it gets propagated > into all other tasks. It's a property of the address space, so it > should really be cleared when a new mm is created (or in dup_mmap > if the mmaps are marked as VM_DONTCOPY). For now we seem to have > no such driver, so leave that for another patch. > > Cc: Sukadev Bhattiprolu > Signed-off-by: Nicholas Piggin > Reviewed-by: Sukadev Bhattiprolu Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/b00b62898631b756c3e123542bbb04 cheers