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Miller" , Andrew Morton , Arnd Bergmann , Andrey Ryabinin , Ignat Korchagin , Stefan Berger , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Eric Biggers , Nathan Chancellor , David Laight , "Jason A. Donenfeld" , Ard Biesheuvel Subject: Re: [PATCH v2] crypto: ecc - Unbreak the build on arm with CONFIG_KASAN_STACK=y Message-ID: References: <7e3d64a53efb28740b32d1f934e78c10086208ab.1778073318.git.lukas@wunner.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Wed, May 06, 2026 at 03:56:22PM +0200, Lukas Wunner wrote: > On Wed, May 06, 2026 at 04:42:25PM +0300, Andy Shevchenko wrote: > > On Wed, May 06, 2026 at 03:27:49PM +0200, Lukas Wunner wrote: > > > A longterm solution is to refactor ecc.c for reduced stack usage. It > > > currently performs ECC point multiplication with a Montgomery ladder > > > which uses co-Z (conjugate) addition to trade off memory for speed. > > > The algorithm is susceptible to timing attacks and needs to be replaced > > > with a constant time Montgomery ladder, which should consume less memory > > > and thus resolve the stack usage issue as a side effect. [...] > > > +# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124949 > > > > Perhaps also mention the algo change as that one sounds to me even more > > critical than this issue per se. > > Hm, but it's already mentioned above in the commit message? Commit message != Makefile (or any other in-tree file). But if you think that this is enough, I am not going to object, it would just require a few steps to get that from the line in file. -- With Best Regards, Andy Shevchenko