From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 4888E388A838; Thu, 6 May 2021 10:51:48 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4888E388A838 From: "ecree429 at virginmedia dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/100444] std::random_device isn't random on AMD Date: Thu, 06 May 2021 10:51:48 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Version: 10.2.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ecree429 at virginmedia dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 May 2021 10:51:48 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100444 --- Comment #7 from Edward Cree --- (In reply to Richard Biener from comment #4) > people that > cannot be bothered to update their ucode or the kernel are not likely > bothered to update libstdc++ either. Fwiw, my kernel is fairly up-to-date (5.9.0-3-amd64); it and my libstdc++ g= et updates pretty regularly from the distro, whereas (like most normal folks) I don't tend to reflash my BIOS without a good reason. (Which this is, I gra= nt you, but I only found out recently that it was causing me any issues, and I= 'm holding off on the update in case affected projects want me to test mitigat= ions / run additional experiments on the buggy hw.) And while Debian can apply updated ucode at boot-time, it's not enabled by default because the ucode binaries are non-free. So a user of a freedom-respecting OS, following normal routine update procedures, will automatically get libstdc++ updates but not ucode updates. But if, having considered it, you decide it's not worth it for libstdc++ to mitigate this, that's fine by me =E2=80=94 after all, now that I know about= the issue, I can fix my system. Question is whether you want to try to protect other users from hitting the same thing.=