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 X-Spam-Level: X-Spam-Status: No, score=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F3EAC04AAD for ; Mon, 6 May 2019 14:54:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D583F2053B for ; Mon, 6 May 2019 14:54:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154453; bh=9XJoIW3im0c4o9kP86IKLI5/0HF/dfsUCxOv8kUS0xA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lHDGsAbd+DXM6Z+Sv6hIPVczzx0wI+1QcRPqNetVe/9wv8dJpg2zd1XhND68hgZOp v50KDsRjKfNyq8vlv/d27xaJyBDJg65bNDMgscc0DsGUtJPMwavJPbHnUZ7sqXALEd RiKjulTtQlcvhBn3u3eXoC4UJoRzf+Db0M5WUnq4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729222AbfEFOrC (ORCPT ); Mon, 6 May 2019 10:47:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:45454 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728064AbfEFOq6 (ORCPT ); Mon, 6 May 2019 10:46:58 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DA3982053B; Mon, 6 May 2019 14:46:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557154017; bh=9XJoIW3im0c4o9kP86IKLI5/0HF/dfsUCxOv8kUS0xA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c/TmI0SpcsMfzwpocrXAwZDZtN7agpHYMy07YaR8HZ9TSQ1r6qpqPFL1YQB29MUPV ew0k/Jh58iiGNN1ItN/m8kEyy6rImKkJ9OnMjOEnZGCCr2BLKGMTBieKiEuKD0COz+ HaCwquvEeYc6tfeH1W81sEb5n/u5hIjESDN6YTm0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Catalin Marinas , Qian Cai , Paul Mackerras , Benjamin Herrenschmidt , Avi Kivity , Paolo Bonzini , Radim Krcmar , Andrew Morton , Linus Torvalds , Sasha Levin , Michael Ellerman Subject: [PATCH 4.14 52/75] kmemleak: powerpc: skip scanning holes in the .bss section Date: Mon, 6 May 2019 16:33:00 +0200 Message-Id: <20190506143057.956132371@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190506143053.287515952@linuxfoundation.org> References: <20190506143053.287515952@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 298a32b132087550d3fa80641ca58323c5dfd4d9 ] Commit 2d4f567103ff ("KVM: PPC: Introduce kvm_tmp framework") adds kvm_tmp[] into the .bss section and then free the rest of unused spaces back to the page allocator. kernel_init kvm_guest_init kvm_free_tmp free_reserved_area free_unref_page free_unref_page_prepare With DEBUG_PAGEALLOC=y, it will unmap those pages from kernel. As the result, kmemleak scan will trigger a panic when it scans the .bss section with unmapped pages. This patch creates dedicated kmemleak objects for the .data, .bss and potentially .data..ro_after_init sections to allow partial freeing via the kmemleak_free_part() in the powerpc kvm_free_tmp() function. Link: http://lkml.kernel.org/r/20190321171917.62049-1-catalin.marinas@arm.com Signed-off-by: Catalin Marinas Reported-by: Qian Cai Acked-by: Michael Ellerman (powerpc) Tested-by: Qian Cai Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Avi Kivity Cc: Paolo Bonzini Cc: Radim Krcmar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- arch/powerpc/kernel/kvm.c | 7 +++++++ mm/kmemleak.c | 16 +++++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c index 9ad37f827a97..7b59cc853abf 100644 --- a/arch/powerpc/kernel/kvm.c +++ b/arch/powerpc/kernel/kvm.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -712,6 +713,12 @@ static void kvm_use_magic_page(void) static __init void kvm_free_tmp(void) { + /* + * Inform kmemleak about the hole in the .bss section since the + * corresponding pages will be unmapped with DEBUG_PAGEALLOC=y. + */ + kmemleak_free_part(&kvm_tmp[kvm_tmp_index], + ARRAY_SIZE(kvm_tmp) - kvm_tmp_index); free_reserved_area(&kvm_tmp[kvm_tmp_index], &kvm_tmp[ARRAY_SIZE(kvm_tmp)], -1, NULL); } diff --git a/mm/kmemleak.c b/mm/kmemleak.c index d9e0be2a8189..337be9aacb7a 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1492,11 +1492,6 @@ static void kmemleak_scan(void) } rcu_read_unlock(); - /* data/bss scanning */ - scan_large_block(_sdata, _edata); - scan_large_block(__bss_start, __bss_stop); - scan_large_block(__start_ro_after_init, __end_ro_after_init); - #ifdef CONFIG_SMP /* per-cpu sections scanning */ for_each_possible_cpu(i) @@ -2027,6 +2022,17 @@ void __init kmemleak_init(void) } local_irq_restore(flags); + /* register the data/bss sections */ + create_object((unsigned long)_sdata, _edata - _sdata, + KMEMLEAK_GREY, GFP_ATOMIC); + create_object((unsigned long)__bss_start, __bss_stop - __bss_start, + KMEMLEAK_GREY, GFP_ATOMIC); + /* only register .data..ro_after_init if not within .data */ + if (__start_ro_after_init < _sdata || __end_ro_after_init > _edata) + create_object((unsigned long)__start_ro_after_init, + __end_ro_after_init - __start_ro_after_init, + KMEMLEAK_GREY, GFP_ATOMIC); + /* * This is the point where tracking allocations is safe. Automatic * scanning is started during the late initcall. Add the early logged -- 2.20.1