From patchwork Mon May 6 14:50:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= X-Patchwork-Id: 10931221 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AB7F11515 for ; Mon, 6 May 2019 15:05:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9ACFF205AD for ; Mon, 6 May 2019 15:05:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8F44F2878F; Mon, 6 May 2019 15:05:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.0 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 425FA205AD for ; Mon, 6 May 2019 15:05:32 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hNf9a-0004MD-Id; Mon, 06 May 2019 15:03:42 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hNf9Z-0004Lm-7r for xen-devel@lists.xenproject.org; Mon, 06 May 2019 15:03:41 +0000 X-Inumbo-ID: 1e4c2b40-7010-11e9-8e99-d39ca5764b89 Received: from new1-smtp.messagingengine.com (unknown [66.111.4.221]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 1e4c2b40-7010-11e9-8e99-d39ca5764b89; Mon, 06 May 2019 15:03:34 +0000 (UTC) Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailnew.nyi.internal (Postfix) with ESMTP id CDDA4136C5; Mon, 6 May 2019 11:03:33 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute7.internal (MEProxy); Mon, 06 May 2019 11:03:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:in-reply-to:message-id:mime-version :references:references:subject:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=j/pJrzCOwItYX2g5i YLCnlWTe3eZ4MWUfdEkcvCwSsY=; b=6Ery8UZmLD7b8zuTkTUYeatEQOZsiBWVq NYtuDU2FnXdZPIngs/sUvHZY0+oO4wirM3bcF8yAN7/a4yslPyqF6FhjkL4mLZN4 HVRQP8S8G4GcReLK+k+Tau7ko2vLcFVnbhgD5a0e5xwUiO6AL3B8NtvC4A2t5rMd NcrCPwtINc6PXF4BpAoCLov4Oqr2cdKsUEePzayDDa89/HdkUHqfxz5s0PHXuP7N Uf8GdHTC3rlMsamblmVwvA8naUSfI6tzLyyvj8yBa9wmGRkPaE7/ubziLmTg8IG3 H/9Nkpc8Kph989BSfB8prH40x5pe16V8edRg029Pqf93uMO6bHZdg== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduuddrjeejgdekiecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenog fthfevqddqjfgurhdqufhushhpvggtthdqlhhoficuldehmdenucfjughrpefhvffufffk ofgjfhggjghftgfgsehtkeertdertdejnecuhfhrohhmpeforghrvghkucforghrtgiihi hkohifshhkihdqifpkrhgvtghkihcuoehmrghrmhgrrhgvkhesihhnvhhishhisghlvght hhhinhhgshhlrggsrdgtohhmqeenucfkphepledurdeihedrfeegrdeffeenucfrrghrrg hmpehmrghilhhfrhhomhepmhgrrhhmrghrvghksehinhhvihhsihgslhgvthhhihhnghhs lhgrsgdrtghomhenucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from localhost.localdomain (ip5b412221.dynamic.kabel-deutschland.de [91.65.34.33]) by mail.messagingengine.com (Postfix) with ESMTPA id BBED71037C; Mon, 6 May 2019 11:03:31 -0400 (EDT) From: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= To: xen-devel@lists.xenproject.org Date: Mon, 6 May 2019 16:50:17 +0200 Message-Id: X-Mailer: git-send-email 2.17.2 In-Reply-To: References: MIME-Version: 1.0 In-Reply-To: References: Subject: [Xen-devel] [PATCH 1/5] xen/bitmap: fix bitmap_fill with zero-sized bitmap X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ian Jackson , =?utf-8?q?Marek_Marczykowski-G?= =?utf-8?q?=C3=B3recki?= , Tim Deegan , Julien Grall , Jan Beulich Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP When bitmap_fill(..., 0) is called, do not try to write anything. Before this patch, it tried to write almost LONG_MAX, surely overwriting something. Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Andrew Cooper Reviewed-by: Jan Beulich --- Found while debugging framebuffer located above 4GB. In that case 32bit variable for it overflows and framebuffer initialization zeroed unrelated memory. Specifically, it hit mbi->mods_count, so later on bitmap_fill(module_map, mbi->mods_count) in __start_xen() crashed. --- xen/include/xen/bitmap.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/xen/include/xen/bitmap.h b/xen/include/xen/bitmap.h index fe3c720..0430c1c 100644 --- a/xen/include/xen/bitmap.h +++ b/xen/include/xen/bitmap.h @@ -126,6 +126,8 @@ static inline void bitmap_fill(unsigned long *dst, int nbits) size_t nlongs = BITS_TO_LONGS(nbits); switch (nlongs) { + case 0: + break; default: memset(dst, -1, (nlongs - 1) * sizeof(unsigned long)); /* fall through */