From 54ec85dd2902bd5dee39106d5291f71088b7d85a Mon Sep 17 00:00:00 2001 From: Jian J Wang Date: Wed, 11 Apr 2018 14:12:12 +0800 Subject: [PATCH 1/1] MdeModulePkg/PiSmmIpl: fix non-executable SMM RAM This patch fixes an issue introduced by commit 5b91bf82c67b586b9588cbe4bbffa1588f6b5926 and 0c9f2cb10b7ddec56a3440e77219fd3ab1725e5c This issue will only happen if PcdDxeNxMemoryProtectionPolicy is enabled for reserved memory, which will mark SMM RAM as NX (non- executable) during DXE core initialization. SMM IPL driver will unset the NX attribute for SMM RAM to allow loading and running SMM core/drivers. But above commit will fail the unset operation of the NX attribute due to a fact that SMM RAM has zero cache attribute (MRC code always sets 0 attribute to reserved memory), which will cause GCD internal method ConverToCpuArchAttributes() to return 0 attribute, which is taken as invalid CPU paging attribute and skip the calling of gCpu->SetMemoryAttributes(). The solution is to make use of existing functionality in PiSmmIpl to make sure one cache attribute is set for SMM RAM. For performance consideration, PiSmmIpl will always try to set SMM RAM to write-back. But there's a hole in the code which will fail the setting write-back attribute because of no corresponding cache capabilities. This patch will add necessary cache capabilities before setting corresponding attributes. Cc: Star Zeng Cc: Eric Dong Cc: Jiewen Yao Cc: Ruiyu Ni Cc: Michael D Kinney Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang Reviewed-by: Star Zeng --- MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c | 50 ++++++++++++++++++-------- 1 file changed, 36 insertions(+), 14 deletions(-) diff --git a/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c b/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c index 94d671bd74..7732693198 100644 --- a/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c +++ b/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c @@ -42,6 +42,14 @@ #include "PiSmmCorePrivateData.h" +#define SMRAM_CAPABILITIES (EFI_MEMORY_WB | EFI_MEMORY_UC) + +#define MEMORY_CACHE_ATTRIBUTES (EFI_MEMORY_UC | EFI_MEMORY_WC | \ + EFI_MEMORY_WT | EFI_MEMORY_WB | \ + EFI_MEMORY_WP | EFI_MEMORY_UCE) + +#define MEMORY_PAGE_ATTRIBUTES (EFI_MEMORY_XP | EFI_MEMORY_RP | EFI_MEMORY_RO) + // // Function prototypes from produced protocols // @@ -1617,34 +1625,48 @@ SmmIplEntry ( GetSmramCacheRange (mCurrentSmramRange, &mSmramCacheBase, &mSmramCacheSize); // + // Make sure we can change the desired memory attributes. + // + Status = gDS->GetMemorySpaceDescriptor ( + mSmramCacheBase, + &MemDesc + ); + ASSERT_EFI_ERROR (Status); + if ((MemDesc.Capabilities & SMRAM_CAPABILITIES) != SMRAM_CAPABILITIES) { + gDS->SetMemorySpaceCapabilities ( + mSmramCacheBase, + mSmramCacheSize, + MemDesc.Capabilities | SMRAM_CAPABILITIES + ); + } + // // If CPU AP is present, attempt to set SMRAM cacheability to WB and clear - // XP if it's set. + // all paging attributes. // Note that it is expected that cacheability of SMRAM has been set to WB if CPU AP // is not available here. // CpuArch = NULL; Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&CpuArch); if (!EFI_ERROR (Status)) { - Status = gDS->SetMemorySpaceAttributes( - mSmramCacheBase, + MemDesc.Attributes &= ~(MEMORY_CACHE_ATTRIBUTES | MEMORY_PAGE_ATTRIBUTES); + MemDesc.Attributes |= EFI_MEMORY_WB; + Status = gDS->SetMemorySpaceAttributes ( + mSmramCacheBase, mSmramCacheSize, - EFI_MEMORY_WB + MemDesc.Attributes ); if (EFI_ERROR (Status)) { DEBUG ((DEBUG_WARN, "SMM IPL failed to set SMRAM window to EFI_MEMORY_WB\n")); } - Status = gDS->GetMemorySpaceDescriptor( - mCurrentSmramRange->PhysicalStart, - &MemDesc - ); - if (!EFI_ERROR (Status) && (MemDesc.Attributes & EFI_MEMORY_XP) != 0) { - gDS->SetMemorySpaceAttributes ( - mCurrentSmramRange->PhysicalStart, - mCurrentSmramRange->PhysicalSize, - MemDesc.Attributes & (~EFI_MEMORY_XP) + DEBUG_CODE ( + gDS->GetMemorySpaceDescriptor ( + mSmramCacheBase, + &MemDesc ); - } + DEBUG ((DEBUG_INFO, "SMRAM attributes: %016lx\n", MemDesc.Attributes)); + ASSERT ((MemDesc.Attributes & MEMORY_PAGE_ATTRIBUTES) == 0); + ); } // // if Loading module at Fixed Address feature is enabled, save the SMRAM base to Load -- 2.39.2