From patchwork Tue Jan 23 00:27:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 13526714 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A6882C47DDF for ; Tue, 23 Jan 2024 00:37:18 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 383B610E717; Tue, 23 Jan 2024 00:37:13 +0000 (UTC) Received: from mail-pj1-f54.google.com (mail-pj1-f54.google.com [209.85.216.54]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4371F10F186 for ; Tue, 23 Jan 2024 00:37:12 +0000 (UTC) Received: by mail-pj1-f54.google.com with SMTP id 98e67ed59e1d1-29026523507so2861259a91.0 for ; Mon, 22 Jan 2024 16:37:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1705970172; x=1706574972; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ci14tXfoLWF8H9KP6TbhVJPvd4jolXPuWJ+qfgosDMI=; b=a/5e/l9BsAGxzmAjvgSC6N2bFCkGFfHJOrT8+ibsKzslv1iCO2YwljyvrO4a8L65Jk Vyw9xsZSN2ccrFoNfORY9rN69rQS6uMjXdyxCxYRPSEEnfLY0CmeaDc64hdJvNN9iYcr 6LiSa4lRWR6LasZRtdqbQFl2jWPjKWkli9e2Q= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705970172; x=1706574972; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ci14tXfoLWF8H9KP6TbhVJPvd4jolXPuWJ+qfgosDMI=; b=eGzFUVymsPxjgFF1WFY9eFAMu3HlFG4ICsX54HBOGimmJWnk6NT31nbeRvi4fuQqk+ wWqN2mF7iO/u5cbdmm1mg+rUgp8gUA//yDVV34JNy3yAEsYAiiYJWrKmRNV19vvCIp2u KiCjPiopTR4TPiSfv8SLrGJreywFFiAMOeRNPITzxCAaBphWPNl/6aObcV4B/1cXVmUo GsbVYnzMDn50/6FVi4YB6INdk27FRHDAId+/Ze83F/Zh4FAHTDOM0BD3QWJwXvRKf1Qh TUw9y6Q5+T+IONQKLJcotGVnYDWZtwB3XtwVxxru7JxVYc0rNGFlkQ90CPuTuzJ87T+P BLuA== X-Gm-Message-State: AOJu0YyIshXFC3wFaY0e30LY/OIRAhRLCQM5aiLdS9NzOZ44sE0MtVcd V8QgzqqbUT2CDcysjxcvrDj2e+v/WrCZFxK8N1j61sUlPTHmAmFL725cbjmBWQ== X-Google-Smtp-Source: AGHT+IHbtzvrk4iZs4Gm8Yr+QrGFjKqhpB03Ocxh4U4TLvusg96tLGgJ15R5wkOaXT55grFNSwGjcg== X-Received: by 2002:a17:90a:62c7:b0:28f:ef2b:e0ed with SMTP id k7-20020a17090a62c700b0028fef2be0edmr2421887pjs.5.1705970171811; Mon, 22 Jan 2024 16:36:11 -0800 (PST) Received: from www.outflux.net ([198.0.35.241]) by smtp.gmail.com with ESMTPSA id sd14-20020a17090b514e00b0028d9fc97c29sm10365268pjb.14.2024.01.22.16.36.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jan 2024 16:36:08 -0800 (PST) From: Kees Cook To: linux-hardening@vger.kernel.org Subject: [PATCH 49/82] drm/i915: Refactor intentional wrap-around test Date: Mon, 22 Jan 2024 16:27:24 -0800 Message-Id: <20240123002814.1396804-49-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240122235208.work.748-kees@kernel.org> References: <20240122235208.work.748-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2342; i=keescook@chromium.org; h=from:subject; bh=oiG+TsWcxpCmRd1+V7WC6Rzkst0Tmp3FWPUBfyk7tD0=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlrwgJM8j5gj77tQNAWNgLrGW9Rf152U5LzsLsJ LLY7jY3zQCJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZa8ICQAKCRCJcvTf3G3A JlTyD/9tInsgMQJNhzXLV4lkjEdwrZuxy10l8+2Dh6eeSAQbaL+DgNMujkfU/ewIc6vsc6zeZLn 3ACm3O16LQN/0j5S0RYKIeVgjfXSZAYGJuwYmW3jBM3o8s9hNPi/SXXGp0toQyaZ73L3hcRB4AO 2C01S7JnD87/2LBgN5VfyCDAUOfgYSqdE4ibXD+3+uyUSrbM8B+GimE4cH4ORUxm7YMLto9zpu+ oxqd7qMyF6AyMavkv5ySlinqmiOVJ83f+YZ+oRowh0q5fTfSibio56QvEqpQZCtefn09GEz+IoC Tnb8E/IS3JJOLLdskrUiX3bNAd51XjStK5+qpc0F35indv1uLzV53YFhU5912hmIDcxwPmmtHTi OXiRWa2TWfKEgQKSVyJmGL9esA3rmPtERr7goeI8/nFMWEb4Qy+cpevxG1qft33h0Z7enHXDTBT JHJYXrmewrWmRrBpNFH54MHVPInL6YqLuU56FYnU3go2zz3tsoo8VutSaww+foZj6VUcti/X6fF PHZBFPajfhvY94xWQMXnk+iHmY7GJNwyVxOdnF8YsTZv23cXzWc9GXdAMMp6lw4By2hz73i3BNZ JSnAMxGSHmwnz/DNjaVSvjUSE5b/U82hIxtLLj6mKkDb5Osg8f47u2KWYVVd868CRAaVvfeVUVJ 1IBIdYvVvwQ4wvw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dri-devel@lists.freedesktop.org, Justin Stitt , Kees Cook , intel-gfx@lists.freedesktop.org, "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, Maxime Ripard , Thomas Zimmermann , Rodrigo Vivi , Daniel Vetter , David Airlie , Bill Wendling Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" In an effort to separate intentional arithmetic wrap-around from unexpected wrap-around, we need to refactor places that depend on this kind of math. One of the most common code patterns of this is: VAR + value < VAR Notably, this is considered "undefined behavior" for signed and pointer types, which the kernel works around by using the -fno-strict-overflow option in the build[1] (which used to just be -fwrapv). Regardless, we want to get the kernel source to the position where we can meaningfully instrument arithmetic wrap-around conditions and catch them when they are unexpected, regardless of whether they are signed[2], unsigned[3], or pointer[4] types. Refactor open-coded wrap-around addition test to use add_would_overflow(). This paves the way to enabling the wrap-around sanitizers in the future. Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f18536594 [1] Link: https://github.com/KSPP/linux/issues/26 [2] Link: https://github.com/KSPP/linux/issues/27 [3] Link: https://github.com/KSPP/linux/issues/344 [4] Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: Tvrtko Ursulin Cc: David Airlie Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Kees Cook --- drivers/gpu/drm/i915/i915_vma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index d09aad34ba37..1a4f048a5df9 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -1535,7 +1535,7 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww, goto err_remove; /* There should only be at most 2 active bindings (user, global) */ - GEM_BUG_ON(bound + I915_VMA_PAGES_ACTIVE < bound); + GEM_BUG_ON(add_would_overflow(bound, I915_VMA_PAGES_ACTIVE)); atomic_add(I915_VMA_PAGES_ACTIVE, &vma->pages_count); list_move_tail(&vma->vm_link, &vma->vm->bound_list);