From patchwork Mon Feb 23 16:24:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alex Deucher X-Patchwork-Id: 5866891 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 134729F169 for ; Mon, 23 Feb 2015 16:24:52 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3666C2063B for ; Mon, 23 Feb 2015 16:24:51 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id BD9DB20637 for ; Mon, 23 Feb 2015 16:24:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BE25589F3B; Mon, 23 Feb 2015 08:24:48 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-vc0-f178.google.com (mail-vc0-f178.google.com [209.85.220.178]) by gabe.freedesktop.org (Postfix) with ESMTP id A82446E3CA for ; Mon, 23 Feb 2015 08:24:47 -0800 (PST) Received: by mail-vc0-f178.google.com with SMTP id hq11so7744075vcb.9 for ; Mon, 23 Feb 2015 08:24:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=Fvg4ex3HUMWILDvA/uUlB7MAH6CtbU4xJtEOwPVBJ20=; b=wNYR0WtocE3tT92tFHl3JbrSwtWusPfe7IahoRailjq3RLpeYhSPhCcXRHdPeydv5Z MeDIi+7xxeumm7aX1PSDqcBF2ZQvHXaAPrvnN7TPhsKSiv/Rog1JdmoKPrT5FdNRsdgj qB9GQF254hmShaCELKsZu3W57PNcCtOXyOq+Zj0Q53DWmD2DCC4itHBbgpoeBQ72IaFn gTODbLzXLKVlS021bEKdvzkHtbDkBjhbLSn8AuokZdUuEx/eMfMTi0oRTAVHjtYy4/F/ WrOM/gtgFYbPWHcJ7bGMohNJM+BC/NzEFWlzaZXQGZzGBdLnZPOklQK4029/2/7BpAY7 qwvw== X-Received: by 10.52.99.230 with SMTP id et6mr11104369vdb.65.1424708685944; Mon, 23 Feb 2015 08:24:45 -0800 (PST) Received: from localhost.localdomain (static-74-96-105-49.washdc.fios.verizon.net. [74.96.105.49]) by mx.google.com with ESMTPSA id uv11sm537026vdb.10.2015.02.23.08.24.44 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 Feb 2015 08:24:45 -0800 (PST) From: Alex Deucher X-Google-Original-From: Alex Deucher To: dri-devel@lists.freedesktop.org Subject: [PATCH] drm/radeon: fix atom aux payload size check for writes (v2) Date: Mon, 23 Feb 2015 11:24:39 -0500 Message-Id: <1424708679-10581-1-git-send-email-alexander.deucher@amd.com> X-Mailer: git-send-email 1.8.3.1 Cc: Alex Deucher X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The atom aux param interface only supports 4 bits for the total write transfer size (header + payload). This limits us to 12 bytes of payload rather than 16. Add a check for this. Reads are not affected. v2: switch to WARN_ON_ONCE Signed-off-by: Alex Deucher Reviewed-by: Michel Dänzer --- drivers/gpu/drm/radeon/atombios_dp.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index 5bf825d..8d74de8 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -178,6 +178,13 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) switch (msg->request & ~DP_AUX_I2C_MOT) { case DP_AUX_NATIVE_WRITE: case DP_AUX_I2C_WRITE: + /* The atom implementation only supports writes with a max payload of + * 12 bytes since it uses 4 bits for the total count (header + payload) + * in the parameter space. The atom interface supports 16 byte + * payloads for reads. The hw itself supports up to 16 bytes of payload. + */ + if (WARN_ON_ONCE(msg->size > 12)) + return -E2BIG; /* tx_size needs to be 4 even for bare address packets since the atom * table needs the info in tx_buf[3]. */