From nobody Sun Sep 7 12:19:04 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C502AECAAD5 for ; Fri, 2 Sep 2022 12:41:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236502AbiIBMld (ORCPT ); Fri, 2 Sep 2022 08:41:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237334AbiIBMjQ (ORCPT ); Fri, 2 Sep 2022 08:39:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A92263AD; Fri, 2 Sep 2022 05:30:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2029762109; Fri, 2 Sep 2022 12:28:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22F26C433C1; Fri, 2 Sep 2022 12:28:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662121717; bh=dwulq3C42+QL6V1OJqh9EVSXbXuaeZA6njsv2Gq/iEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v6Ar2SGZSxOt8cH1N4sKFDjTU7UKIggsaZTJYm9rBB8eCEFhG3pz3FvgBniNpmmyu rgamyLU+OiJy6fe3rdOV7auzORKHMg8sS8YJ6bcdKTXiHygZ+Bz4IETjQ8u6GP4cad qWZ9uemA+Hx3Jv2KHVmftUIDrdHVcMM+8+66FvXg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Quanyang Wang , Ard Biesheuvel , Arnd Bergmann , Thierry Reding , Andrew Morton Subject: [PATCH 5.4 42/77] asm-generic: sections: refactor memory_intersects Date: Fri, 2 Sep 2022 14:18:51 +0200 Message-Id: <20220902121405.050717759@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220902121403.569927325@linuxfoundation.org> References: <20220902121403.569927325@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Quanyang Wang commit 0c7d7cc2b4fe2e74ef8728f030f0f1674f9f6aee upstream. There are two problems with the current code of memory_intersects: First, it doesn't check whether the region (begin, end) falls inside the region (virt, vend), that is (virt < begin && vend > end). The second problem is if vend is equal to begin, it will return true but this is wrong since vend (virt + size) is not the last address of the memory region but (virt + size -1) is. The wrong determination will trigger the misreporting when the function check_for_illegal_area calls memory_intersects to check if the dma region intersects with stext region. The misreporting is as below (stext is at 0x80100000): WARNING: CPU: 0 PID: 77 at kernel/dma/debug.c:1073 check_for_illegal_area+= 0x130/0x168 DMA-API: chipidea-usb2 e0002000.usb: device driver maps memory from kernel= text or rodata [addr=3D800f0000] [len=3D65536] Modules linked in: CPU: 1 PID: 77 Comm: usb-storage Not tainted 5.19.0-yocto-standard #5 Hardware name: Xilinx Zynq Platform unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x58/0x70 dump_stack_lvl from __warn+0xb0/0x198 __warn from warn_slowpath_fmt+0x80/0xb4 warn_slowpath_fmt from check_for_illegal_area+0x130/0x168 check_for_illegal_area from debug_dma_map_sg+0x94/0x368 debug_dma_map_sg from __dma_map_sg_attrs+0x114/0x128 __dma_map_sg_attrs from dma_map_sg_attrs+0x18/0x24 dma_map_sg_attrs from usb_hcd_map_urb_for_dma+0x250/0x3b4 usb_hcd_map_urb_for_dma from usb_hcd_submit_urb+0x194/0x214 usb_hcd_submit_urb from usb_sg_wait+0xa4/0x118 usb_sg_wait from usb_stor_bulk_transfer_sglist+0xa0/0xec usb_stor_bulk_transfer_sglist from usb_stor_bulk_srb+0x38/0x70 usb_stor_bulk_srb from usb_stor_Bulk_transport+0x150/0x360 usb_stor_Bulk_transport from usb_stor_invoke_transport+0x38/0x440 usb_stor_invoke_transport from usb_stor_control_thread+0x1e0/0x238 usb_stor_control_thread from kthread+0xf8/0x104 kthread from ret_from_fork+0x14/0x2c Refactor memory_intersects to fix the two problems above. Before the 1d7db834a027e ("dma-debug: use memory_intersects() directly"), memory_intersects is called only by printk_late_init: printk_late_init -> init_section_intersects ->memory_intersects. There were few places where memory_intersects was called. When commit 1d7db834a027e ("dma-debug: use memory_intersects() directly") was merged and CONFIG_DMA_API_DEBUG is enabled, the DMA subsystem uses it to check for an illegal area and the calltrace above is triggered. [akpm@linux-foundation.org: fix nearby comment typo] Link: https://lkml.kernel.org/r/20220819081145.948016-1-quanyang.wang@windr= iver.com Fixes: 979559362516 ("asm/sections: add helpers to check for section data") Signed-off-by: Quanyang Wang Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Thierry Reding Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- include/asm-generic/sections.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/include/asm-generic/sections.h +++ b/include/asm-generic/sections.h @@ -114,7 +114,7 @@ static inline bool memory_contains(void /** * memory_intersects - checks if the region occupied by an object intersec= ts * with another memory region - * @begin: virtual address of the beginning of the memory regien + * @begin: virtual address of the beginning of the memory region * @end: virtual address of the end of the memory region * @virt: virtual address of the memory object * @size: size of the memory object @@ -127,7 +127,10 @@ static inline bool memory_intersects(voi { void *vend =3D virt + size; =20 - return (virt >=3D begin && virt < end) || (vend >=3D begin && vend < end); + if (virt < end && vend > begin) + return true; + + return false; } =20 /**