From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <7443.1506978724.1@warthog.procyon.org.uk> Content-Transfer-Encoding: quoted-printable Date: Mon, 02 Oct 2017 22:12:04 +0100 Message-ID: <7444.1506978724@warthog.procyon.org.uk> Subject: [kernel-hardening] Re: Modular BIG_KEYS (was: Re: [PATCH v4] security/keys: rewrite all of big_key crypto) To: Geert Uytterhoeven Cc: dhowells@redhat.com, "Jason A. Donenfeld" , linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, kernel-hardening@lists.openwall.com, "linux-kernel@vger.kernel.org" , ebiggers3@gmail.com, Herbert Xu , Kirill Marinushkin , Ard Biesheuvel , Ilhan Gurel , security@kernel.org, stable List-ID: Geert Uytterhoeven wrote: > Now this has hit mainline, the "BIG_KEYS" Kconfig symbol appeared on my > radar. Is there any reason this cannot be tristate? It was tristate, but it got converted to bool: commit 2eaf6b5dcafda2b8c22930eff7f48a364fce1741 KEYS: Make BIG_KEYS boolean and then: commit a1f2bdf338f15dbad10ee6362891ebf79244858b security/keys: make big_key.c explicitly non-modular > So to save kernel size, I wan't to save N, but for a distro kernel that = might > have Kerberos users, you currently need to say Y, while M would be nicer= . If you want to do that, you'll need to implement demand-loading of key typ= e modules. Note that you'd end up using a minimum of a whole page as a module rather = than ~2K if built in (I know, that's a compromise you have to decide on). David