From mboxrd@z Thu Jan 1 00:00:00 1970 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 3465CC433FE for ; Tue, 12 Apr 2022 12:57:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354245AbiDLM71 (ORCPT ); Tue, 12 Apr 2022 08:59:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355146AbiDLM5w (ORCPT ); Tue, 12 Apr 2022 08:57:52 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C92CC59A55; Tue, 12 Apr 2022 05:31:30 -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 ams.source.kernel.org (Postfix) with ESMTPS id 7B941B81D2D; Tue, 12 Apr 2022 12:31:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34F2FC385A6; Tue, 12 Apr 2022 12:31:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649766688; bh=qvgvgPlnqIF4Nwhd/KVD2DfqHWxVoFnWvDT/T+pTUxg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=gTRMUm9FpmPdmWAYUNF0Kc1HCctRfKCsfzRNc8O0rE2QQNaVs7Bbf3tO3vEpfeGyB 47992792v7zS+xdeFT9wflnpVYqhWy/HbjpSHRFIzC9cgzzOhLa8ciB6t+6fKAlE/b pEckANQRnyja2+s6hKMB7oTTHQMz2esUuQQ3BZL7GME/qxyNtNtXaOMWQhOdgnxBU4 8zXSGsbrGWqonXrebx/UcEuPe11BJ+sfypdhvHLk55txlYM8yy91qmKEMyKSty9Z4A TVe5BgdOyX5yOIu13InAyvW0wlloyI6adBEcilfN2wdOpCN5A0UGQZASr1b4L7Z87c caY85b2Z+Q+sg== Received: by mail-io1-f46.google.com with SMTP id r2so22030592iod.9; Tue, 12 Apr 2022 05:31:28 -0700 (PDT) X-Gm-Message-State: AOAM533bBAbNFQoXpLFchMd9p6ApHn5yASO7/oI/QpZgxGXumvqGwz6S ywytT+cq/etYYTwW4Ef/onPdp85OYK5rEiYxaw== X-Google-Smtp-Source: ABdhPJzysinMng65dytPxyEs+g/U4hp7xMDUjNUwYTOhCqrvOU3/Ba48iG7ejIU9HPu1N2kuCqqb1gTfROoyF+ACUnU= X-Received: by 2002:a05:6602:1645:b0:646:4780:fc28 with SMTP id y5-20020a056602164500b006464780fc28mr15420111iow.194.1649766687353; Tue, 12 Apr 2022 05:31:27 -0700 (PDT) MIME-Version: 1.0 References: <20220412045228.35306-1-patrick.wang.shcn@gmail.com> In-Reply-To: <20220412045228.35306-1-patrick.wang.shcn@gmail.com> From: Rob Herring Date: Tue, 12 Apr 2022 07:31:16 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] of: fdt: do not reserve memory below MIN_MEMBLOCK_ADDR To: Patrick Wang , Mike Rapoport Cc: Frank Rowand , devicetree@vger.kernel.org, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org +Mike Rapoport On Mon, Apr 11, 2022 at 11:52 PM Patrick Wang wrote: > > Dt reserve memory without base checking, which will trigger an oops in > kmemleak when the base address is below MIN_MEMBLOCK_ADDR: Why does the caller need to know what this address is? Shouldn't memblock handle all this internally? What about when EFI memory maps are used? > > # echo scan > /sys/kernel/debug/kmemleak > [ 54.888353] Unable to handle kernel paging request at virtual address ff5fffffffe00000 > [ 54.888932] Oops [#1] > [ 54.889102] Modules linked in: > [ 54.889326] CPU: 2 PID: 134 Comm: bash Not tainted 5.18.0-rc1-next-20220407 #33 > [ 54.889620] Hardware name: riscv-virtio,qemu (DT) > [ 54.889901] epc : scan_block+0x74/0x15c > [ 54.890215] ra : scan_block+0x72/0x15c > [ 54.890390] epc : ffffffff801e5806 ra : ffffffff801e5804 sp : ff200000104abc30 > [ 54.890607] gp : ffffffff815cd4e8 tp : ff60000004cfa340 t0 : 0000000000000200 > [ 54.890835] t1 : 00aaaaaac23954cc t2 : 00000000000003ff s0 : ff200000104abc90 > [ 54.891024] s1 : ffffffff81b0ff28 a0 : 0000000000000000 a1 : ff5fffffffe01000 > [ 54.891201] a2 : ffffffff81b0ff28 a3 : 0000000000000002 a4 : 0000000000000001 > [ 54.891377] a5 : 0000000000000000 a6 : ff200000104abd7c a7 : 0000000000000005 > [ 54.891552] s2 : ff5fffffffe00ff9 s3 : ffffffff815cd998 s4 : ffffffff815d0e90 > [ 54.891727] s5 : ffffffff81b0ff28 s6 : 0000000000000020 s7 : ffffffff815d0eb0 > [ 54.891903] s8 : ffffffffffffffff s9 : ff5fffffffe00000 s10: ff5fffffffe01000 > [ 54.892078] s11: 0000000000000022 t3 : 00ffffffaa17db4c t4 : 000000000000000f > [ 54.892271] t5 : 0000000000000001 t6 : 0000000000000000 > [ 54.892408] status: 0000000000000100 badaddr: ff5fffffffe00000 cause: 000000000000000d > [ 54.892643] [] scan_gray_list+0x12e/0x1a6 > [ 54.892824] [] kmemleak_scan+0x2aa/0x57e > [ 54.892961] [] kmemleak_write+0x32a/0x40c > [ 54.893096] [] full_proxy_write+0x56/0x82 > [ 54.893235] [] vfs_write+0xa6/0x2a6 > [ 54.893362] [] ksys_write+0x6c/0xe2 > [ 54.893487] [] sys_write+0x22/0x2a > [ 54.893609] [] ret_from_syscall+0x0/0x2 > [ 54.894183] ---[ end trace 0000000000000000 ]--- > > Add base checking and ignore the range lower than MIN_MEMBLOCK_ADDR. > > Signed-off-by: Patrick Wang > --- > drivers/of/fdt.c | 27 ++++++++++++++++++++------- > 1 file changed, 20 insertions(+), 7 deletions(-) > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index ec315b060..296c4ab8e 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -33,6 +33,13 @@ > > #include "of_private.h" > > +#ifndef MIN_MEMBLOCK_ADDR > +#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) > +#endif > +#ifndef MAX_MEMBLOCK_ADDR > +#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) > +#endif > + > /* > * of_fdt_limit_memory - limit the number of regions in the /memory node > * @limit: maximum entries > @@ -480,6 +487,19 @@ static u32 of_fdt_crc32; > static int __init early_init_dt_reserve_memory_arch(phys_addr_t base, > phys_addr_t size, bool nomap) > { > + const u64 phys_offset = MIN_MEMBLOCK_ADDR; > + > + if (base < phys_offset) { > + pr_warn("Ignoring reserved memory range 0x%llx - 0x%llx\n", > + base, phys_offset); > + size = (phys_offset - base) < size ? > + size - (phys_offset - base) : 0; > + base = phys_offset; > + > + if (!size) > + return -EFAULT; > + } > + > if (nomap) { > /* > * If the memory is already reserved (by another region), we > @@ -1198,13 +1218,6 @@ int __init early_init_dt_scan_chosen(char *cmdline) > return 0; > } > > -#ifndef MIN_MEMBLOCK_ADDR > -#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) > -#endif > -#ifndef MAX_MEMBLOCK_ADDR > -#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) > -#endif > - > void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) > { > const u64 phys_offset = MIN_MEMBLOCK_ADDR; > -- > 2.25.1 >