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 A1BD2C61DA4 for ; Thu, 9 Feb 2023 05:59:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229517AbjBIF7e (ORCPT ); Thu, 9 Feb 2023 00:59:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbjBIF7d (ORCPT ); Thu, 9 Feb 2023 00:59:33 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E77D81B307; Wed, 8 Feb 2023 21:59:32 -0800 (PST) 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 7DA026190B; Thu, 9 Feb 2023 05:59:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A2B4C433EF; Thu, 9 Feb 2023 05:59:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675922371; bh=C3PzIyt2T/NB+g/Zf8/N5OjMn3X2HNTvVkA2m4KLgY4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OculTekPRb8o5jkmwqmVaE7Zf0U8O5GJqyWmZdkRlXkuUXIpjxhrSe3iP5QWlV8os Ev1tH6HbFCUgpiwy5vwBb7n5CK6GQy+fP7f0LA3nCbWXVSnCRLXyBKBFLNOGGoyuo4 Bggg6XiTjJ2pqaFGhALv3rmCqzV1b7jiBJzi1PSYQBI/U32qn0q88X4AZ8r8Rv6d0X Jk9rnpFVv9r+Qvo35TwRjEtjYPT4uuZrdc3GGmS4KVHBGfbcIT11Np/htuueEShFIq X/CZ6D4s0tIyWXXPBFIcdwl9OW29FmtmkYk7q7jRr5Wn5gtzAEK+gqoT9LKwAYS+DH ES3IJfxyBjMYw== Date: Thu, 9 Feb 2023 07:59:17 +0200 From: Mike Rapoport To: "Isaac J. Manjarres" Cc: Rob Herring , Frank Rowand , "Russell King (Oracle)" , "Kirill A. Shutemov" , Nick Kossifidis , Catalin Marinas , Andrew Morton , Saravana Kannan , linux-mm@kvack.org, kernel-team@android.com, "Rafael J. Wysocki" , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Rob Herring Subject: Re: [PATCH v2 1/1] of: reserved_mem: Have kmemleak ignore dynamically allocated reserved mem Message-ID: References: <20230208232001.2052777-1-isaacmanjarres@google.com> <20230208232001.2052777-2-isaacmanjarres@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230208232001.2052777-2-isaacmanjarres@google.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Feb 08, 2023 at 03:20:00PM -0800, Isaac J. Manjarres wrote: > Currently, kmemleak ignores dynamically allocated reserved memory > regions that don't have a kernel mapping. However, regions that do > retain a kernel mapping (e.g. CMA regions) do get scanned by kmemleak. > > This is not ideal for two reasons: > > 1. kmemleak works by scanning memory regions for pointers to > allocated objects to determine if those objects have been leaked > or not. However, reserved memory regions can be used between drivers > and peripherals for DMA transfers, and thus, would not contain pointers > to allocated objects, making it unnecessary for kmemleak to scan > these reserved memory regions. > > 2. When CONFIG_DEBUG_PAGEALLOC is enabled, along with kmemleak, the > CMA reserved memory regions are unmapped from the kernel's address > space when they are freed to buddy at boot. These CMA reserved regions > are still tracked by kmemleak, however, and when kmemleak attempts to > scan them, a crash will happen, as accessing the CMA region will result > in a page-fault, since the regions are unmapped. > > Thus, use kmemleak_ignore_phys() for all dynamically allocated reserved > memory regions, instead of those that do not have a kernel mapping > associated with them. > > Cc: # 5.15+ > Fixes: a7259df76702 ("memblock: make memblock_find_in_range method private") > Signed-off-by: Isaac J. Manjarres Acked-by: Mike Rapoport (IBM) > --- > drivers/of/of_reserved_mem.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c > index 65f3b02a0e4e..f90975e00446 100644 > --- a/drivers/of/of_reserved_mem.c > +++ b/drivers/of/of_reserved_mem.c > @@ -48,9 +48,10 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, > err = memblock_mark_nomap(base, size); > if (err) > memblock_phys_free(base, size); > - kmemleak_ignore_phys(base); > } > > + kmemleak_ignore_phys(base); > + > return err; > } > > -- > 2.39.1.581.gbfd45094c4-goog > -- Sincerely yours, Mike.