From patchwork Wed Jun 24 12:33:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Popov X-Patchwork-Id: 11623047 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6E04D92A for ; Wed, 24 Jun 2020 12:34:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F91320CC7 for ; Wed, 24 Jun 2020 12:34:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389554AbgFXMd6 (ORCPT ); Wed, 24 Jun 2020 08:33:58 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:43251 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388761AbgFXMdz (ORCPT ); Wed, 24 Jun 2020 08:33:55 -0400 Received: by mail-qt1-f196.google.com with SMTP id v19so1464870qtq.10; Wed, 24 Jun 2020 05:33:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8sHQzOYVDYH3ZNMAFgn6qFPgIIglqtoHHBWYdYcv8aA=; b=syuE55D0mXEdb/fxaAmKcNrq0ep91sscASWL5UeF055ScIwGCOWrHKh0oBZjhqqPgI WlSsuDqxkM5y9Z1Q9GXxD38eHuNDOGHncTvW+ZoEFXakXdM/j0/0LyvuXJoJHFk472cu iwmA6dJI9WChsd2TzgeQZKEAi+3rn4x4zNBFbSnZziFnoVvde/Vlgds60tFIKsS3/oUh H/H3lurQElJ0Qvtl5t/9LgM8XPD2e/AfcHR8KB3rOnd66GuyiyxsFjQTMv/7DQIEjilf jJy4hhDyqz6C82vqQa38ZeuwGFvK8/Lfnonmk50XMd1Zp0yebpbZAQf8qJ1PJZYCwQmU 7aPw== X-Gm-Message-State: AOAM531XMax1JvIBWITwoI+h5642Tvk1AIKqU/Jh6B33FYoKXITQChAd r74x4zZamnkg7xc1gSC7Cew= X-Google-Smtp-Source: ABdhPJxblUCjOrDANsgZy0tfdbktunxAZXJLdRpPPWkvHCUo+/qzdIkUPYVzbM2mylESz5Zexu9MIA== X-Received: by 2002:ac8:22e5:: with SMTP id g34mr27227271qta.227.1593002033880; Wed, 24 Jun 2020 05:33:53 -0700 (PDT) Received: from localhost.localdomain ([185.248.161.177]) by smtp.gmail.com with ESMTPSA id x26sm3354512qtr.4.2020.06.24.05.33.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jun 2020 05:33:53 -0700 (PDT) From: Alexander Popov To: Kees Cook , Jann Horn , Emese Revfy , Miguel Ojeda , Masahiro Yamada , Michal Marek , Andrew Morton , Masahiro Yamada , Thiago Jung Bauermann , Luis Chamberlain , Jessica Yu , Sven Schnelle , Iurii Zaikin , Catalin Marinas , Will Deacon , Vincenzo Frascino , Thomas Gleixner , Peter Collingbourne , Naohiro Aota , Alexander Monakov , Mathias Krause , PaX Team , Brad Spengler , Laura Abbott , Florian Weimer , Alexander Popov , kernel-hardening@lists.openwall.com, linux-kbuild@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, gcc@gcc.gnu.org Cc: notify@kernel.org Subject: [PATCH v2 0/5] Improvements of the stackleak gcc plugin Date: Wed, 24 Jun 2020 15:33:25 +0300 Message-Id: <20200624123330.83226-1-alex.popov@linux.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org This is the v2 of the patch series with various improvements of the stackleak gcc plugin. The first three patches disable unneeded gcc plugin instrumentation for some files. The fourth patch is the main improvement. It eliminates an unwanted side-effect of kernel code instrumentation performed by stackleak gcc plugin. This patch is a deep reengineering of the idea described on grsecurity blog: https://grsecurity.net/resolving_an_unfortunate_stackleak_interaction The final patch adds 'verbose' stackleak parameter for printing additional info about the kernel code instrumentation during kernel building. I would like to thank Alexander Monakov for his advisory on gcc internals. This patch series was tested for gcc version 4.8, 5, 6, 7, 8, 9, and 10 on x86_64, i386 and arm64. That was done using the project 'kernel-build-containers': https://github.com/a13xp0p0v/kernel-build-containers Changes from v1: - rebase onto 5.8.0-rc2; - don't exclude alloca() from the instrumentation logic, because it will be used in kernel stack offset randomization; - reorder patches in the series; - don't use gcc plugins for building vgettimeofday.c in arm and arm64 vDSO; - follow alphabetic order in include/linux/compiler_attributes.h. Link to v1: https://lore.kernel.org/lkml/20200604134957.505389-1-alex.popov@linux.com/ Alexander Popov (5): gcc-plugins/stackleak: Don't instrument itself ARM: vdso: Don't use gcc plugins for building vgettimeofday.c arm64: vdso: Don't use gcc plugins for building vgettimeofday.c gcc-plugins/stackleak: Use asm instrumentation to avoid useless register saving gcc-plugins/stackleak: Add 'verbose' plugin parameter arch/arm/vdso/Makefile | 2 +- arch/arm64/kernel/vdso/Makefile | 2 +- include/linux/compiler_attributes.h | 13 ++ kernel/Makefile | 1 + kernel/stackleak.c | 16 +- scripts/Makefile.gcc-plugins | 2 + scripts/gcc-plugins/stackleak_plugin.c | 248 +++++++++++++++++++++---- 7 files changed, 239 insertions(+), 45 deletions(-)