From mboxrd@z Thu Jan 1 00:00:00 1970 From: peterz@infradead.org (Peter Zijlstra) Date: Thu, 28 Jun 2018 11:28:15 +0200 Subject: [PATCH 5/5] x86/kernel: jump_table: use relative references In-Reply-To: References: <20180627160604.8154-1-ard.biesheuvel@linaro.org> <20180627160604.8154-6-ard.biesheuvel@linaro.org> <20180628083107.GY2494@hirez.programming.kicks-ass.net> Message-ID: <20180628092815.GD2494@hirez.programming.kicks-ass.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 28, 2018 at 10:34:54AM +0200, Ard Biesheuvel wrote: > On 28 June 2018 at 10:31, Peter Zijlstra wrote: > > On Wed, Jun 27, 2018 at 06:06:04PM +0200, Ard Biesheuvel wrote: > >> Similar to the arm64 case, 64-bit x86 can benefit from using 32-bit > >> relative references rather than 64-bit absolute ones when emitting > >> struct jump_entry instances. Not only does this reduce the memory > >> footprint of the entries themselves by 50%, it also removes the need > >> for carrying relocation metadata on relocatable builds (i.e., for KASLR) > >> which saves a fair chunk of .init space as well (although the savings > >> are not as dramatic as on arm64) > > > > This will conflict with: > > > > https://lkml.kernel.org/r/20180622172212.199633-10-namit at vmware.com > > Thanks for the head's up. Fortunately, it does not conflict > fundamentally, so it should be a straight-forward rebase after that > code is merged. Yeah, shouldn't be hard to cure. There's another patch set that might have a little conflict, but that's not near ready I think, so that'll have to just cope with things shifting underneath (and there too, the fixup shouldn't be hard). > Do you think this is likely to get merged for v4.19? I'm thinking it is near ready so it might, but I'm not in charge of those bits :-)