From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.120; helo=mga04.intel.com; envelope-from=ruiyu.ni@intel.com; receiver=edk2-devel@lists.01.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 5B5E52239364A for ; Wed, 31 Jan 2018 21:47:00 -0800 (PST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jan 2018 21:52:36 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,443,1511856000"; d="scan'208";a="14169161" Received: from ray-dev.ccr.corp.intel.com (HELO [10.239.9.19]) ([10.239.9.19]) by orsmga007.jf.intel.com with ESMTP; 31 Jan 2018 21:52:35 -0800 To: Jian J Wang , edk2-devel@lists.01.org Cc: Jiewen Yao , Eric Dong , Star Zeng References: <20180129120932.26272-1-jian.j.wang@intel.com> From: "Ni, Ruiyu" Message-ID: Date: Thu, 1 Feb 2018 13:52:34 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <20180129120932.26272-1-jian.j.wang@intel.com> Subject: Re: [PATCH] MdeModulePkg/Core: fix feature conflict between NX and heap guard X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Feb 2018 05:47:00 -0000 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit On 1/29/2018 8:09 PM, Jian J Wang wrote: > Considering following scenario (both NX memory protection and heap guard > are enabled): > > 1. Allocate 3 pages. The attributes of adjacent memory pages will be > > |NOT-PRESENT| present | present | present |NOT-PRESENT| > > 2. Free the middle page. The attributes of adjacent memory pages should > be > > |NOT-PRESENT| present |NOT-PRESENT| present |NOT-PRESENT| > > But the NX feature will overwrite the attributes of middle page. So > it looks still like below, which is wrong. > > |NOT-PRESENT| present | PRESENT | present |NOT-PRESENT| > > The solution is checking the first and/or last page of a memory block to be > marked as NX, and skipping them if they are Guard pages. > > Cc: Star Zeng > Cc: Eric Dong > Cc: Jiewen Yao > Cc: Ruiyu Ni > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Jian J Wang > --- > MdeModulePkg/Core/Dxe/Mem/HeapGuard.c | 14 ++++++++++++++ > MdeModulePkg/Core/Dxe/Mem/HeapGuard.h | 10 ++++++++++ > MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c | 22 ++++++++++++++++++++++ > 3 files changed, 46 insertions(+) > > diff --git a/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c b/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c > index 392aeb8a02..d7906e08c5 100644 > --- a/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c > +++ b/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c > @@ -728,6 +728,20 @@ IsPageTypeToGuard ( > return IsMemoryTypeToGuard (MemoryType, AllocateType, GUARD_HEAP_TYPE_PAGE); > } > > +/** > + Check to see if the heap guard is enabled for page and/or pool allocation. > + > + @return TRUE/FALSE. > +**/ > +BOOLEAN > +IsHeapGuardEnabled ( > + VOID > + ) > +{ > + return IsMemoryTypeToGuard (EfiMaxMemoryType, AllocateAnyPages, > + GUARD_HEAP_TYPE_POOL|GUARD_HEAP_TYPE_PAGE); > +} > + > /** > Set head Guard and tail Guard for the given memory range. > > diff --git a/MdeModulePkg/Core/Dxe/Mem/HeapGuard.h b/MdeModulePkg/Core/Dxe/Mem/HeapGuard.h > index 30ac0e678f..7208ab1437 100644 > --- a/MdeModulePkg/Core/Dxe/Mem/HeapGuard.h > +++ b/MdeModulePkg/Core/Dxe/Mem/HeapGuard.h > @@ -389,6 +389,16 @@ AdjustPoolHeadF ( > IN EFI_PHYSICAL_ADDRESS Memory > ); > > +/** > + Check to see if the heap guard is enabled for page and/or pool allocation. > + > + @return TRUE/FALSE. > +**/ > +BOOLEAN > +IsHeapGuardEnabled ( > + VOID > + ); > + > extern BOOLEAN mOnGuarding; > > #endif > diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c > index 150167bf66..877e6e5025 100644 > --- a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c > +++ b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c > @@ -48,6 +48,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. > #include > > #include "DxeMain.h" > +#include "Mem/HeapGuard.h" > > #define CACHE_ATTRIBUTE_MASK (EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT | EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_WP) > #define MEMORY_ATTRIBUTE_MASK (EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RO) > @@ -1200,6 +1201,27 @@ ApplyMemoryProtectionPolicy ( > return EFI_SUCCESS; > } > > + // > + // Don't overwrite Guard pages, which should be the first and/or last page, > + // if any. > + // > + if (IsHeapGuardEnabled ()) { > + if (IsGuardPage (Memory)) { > + Memory += EFI_PAGE_SIZE; > + Length -= EFI_PAGE_SIZE; > + if (Length == 0) { > + return EFI_SUCCESS; > + } > + } > + > + if (IsGuardPage (Memory + Length - EFI_PAGE_SIZE)) { > + Length -= EFI_PAGE_SIZE; > + if (Length == 0) { > + return EFI_SUCCESS; > + } > + } > + } > + > // > // Update the executable permissions according to the DXE memory > // protection policy, but only if > Reviewed-by: Ruiyu Ni -- Thanks, Ray