From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=34.238.86.106; helo=mail.paulo.ac; envelope-from=paulo@paulo.ac; receiver=edk2-devel@lists.01.org Received: from mail.paulo.ac (mail.paulo.ac [34.238.86.106]) (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 12E1521F833B3 for ; Thu, 4 Jan 2018 07:10:31 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by mail.paulo.ac (Postfix) with ESMTP id 8F2E9C78F0B; Thu, 4 Jan 2018 15:15:35 +0000 (UTC) X-Virus-Scanned: amavisd-new at paulo.ac X-Spam-Flag: NO X-Spam-Score: -1.099 X-Spam-Level: X-Spam-Status: No, score=-1.099 tagged_above=-999 required=6.31 tests=[ALL_TRUSTED=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Authentication-Results: mail.paulo.ac (amavisd-new); dkim=pass (1024-bit key) header.d=paulo.ac Received: from mail.paulo.ac ([127.0.0.1]) by localhost (mail.paulo.ac [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Eq-JOgOVFUOo; Thu, 4 Jan 2018 15:15:30 +0000 (UTC) Received: from localhost (unknown [177.18.159.125]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.paulo.ac (Postfix) with ESMTPSA id F09C2C78F0A; Thu, 4 Jan 2018 15:15:28 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.paulo.ac F09C2C78F0A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=paulo.ac; s=default; t=1515078930; bh=z/Er9yJFTp769P0bc8TqwlVSUWdE1immFd6Ta5v5m/A=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=PwgCVuBizMQrpXwS7xbhTbUtwxaCzxBNtsDZWmKFp0Nkx7eFfwV/cVzA2y6Yz9IBz JFfvq4m+sAv01pgxKY2fRWFbhLXlbbfALqMF3LJmEtpvYaZ6WI1Ah0oU3NKgH85BLf KRqi9ZxeOyVtvPjvWpY5ekZ66F5rsB+wcZmoqA/g= From: Paulo Alcantara To: "Yao\, Jiewen" , "edk2-devel\@lists.01.org" Cc: Laszlo Ersek , "Dong\, Eric" In-Reply-To: <74D8A39837DF1E4DA445A8C0B3885C503AA7079B@shsmsx102.ccr.corp.intel.com> References: <32f06077006939f71560970f6abcbbb2062ea5c3.1514517573.git.paulo@paulo.ac> <74D8A39837DF1E4DA445A8C0B3885C503AA6F95E@shsmsx102.ccr.corp.intel.com> <74D8A39837DF1E4DA445A8C0B3885C503AA6FA0F@shsmsx102.ccr.corp.intel.com> <878tddsqf6.fsf@paulo.ac> <74D8A39837DF1E4DA445A8C0B3885C503AA7079B@shsmsx102.ccr.corp.intel.com> Date: Thu, 04 Jan 2018 13:15:10 -0200 Message-ID: <87wp0xr6yp.fsf@paulo.ac> MIME-Version: 1.0 Subject: Re: [RFC v4 4/6] UefiCpuPkg/CpuExceptionHandlerLib: Add helper to valid memory addresses 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, 04 Jan 2018 15:10:32 -0000 Content-Type: text/plain "Yao, Jiewen" writes: Hi Jiewen, > For 7), you are right that we disable IA32 paging by default. > However, we do support IA32 PAE in DxeIpl. Please refer to MdeModulePkg\Core\DxeIplPeim\Ia32\DxeLoadFunc.c > ====================== > PageTables = 0; > BuildPageTablesIa32Pae = (BOOLEAN) (PcdGetBool (PcdSetNxForStack) && IsIa32PaeSupport () && IsExecuteDisableBitAvailable ()); > if (BuildPageTablesIa32Pae) { > PageTables = Create4GPageTablesIa32Pae (BaseOfStack, STACK_SIZE); > EnableExecuteDisableBit (); > } > ====================== > > Please notice that we only support IA32 PAE, we do not support IA32 > non-PAE mode so far. (no matter PSE is ON/OFF) Cool! I didn't know about it. > > So, I suggest: > 7.1) Please validate IA32 PAE mode. (You can enable PcdSetNxForStack) I will. Thanks! > 7.2) If we cannot validate the IA32 non-PAE code, please remove > them. You can just print "IA32 non-PAE - UNSUPPORTED" and return > invalid address. Then it can save our development time, review time, > and validation time. The key is that we only want to check in the > validated code. You're right. I'll keep only the code that we were able to validate its implementation (e.g. 4-level & 32-bit PAE). Thanks! Paulo >> -----Original Message----- >> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Paulo >> Alcantara >> Sent: Thursday, January 4, 2018 9:30 PM >> To: Yao, Jiewen ; Yao, Jiewen ; >> edk2-devel@lists.01.org >> Cc: Laszlo Ersek ; Dong, Eric >> Subject: Re: [edk2] [RFC v4 4/6] UefiCpuPkg/CpuExceptionHandlerLib: Add >> helper to valid memory addresses >> >> "Yao, Jiewen" writes: >> >> > 5) For CR4, please use meaning definition for BIT4/BIT5. >> > if ((Cr4 & BIT4) != 0 && (*PageDirEntry & BIT7) != 0) { >> > if (((Cr4 & BIT5) != 0 && (UINT64)LinearAddress > 0xFFFFFFFFFULL) || >> >> OK. >> >> > >> > 6) For IA32 PAE/PSE calculation, same comment for 3 and 4. >> >> OK. >> >> > >> > 7) Last but not least important, would you please share the information on >> how do you validate the 32bit PAE/PSE/normal 4K page table? >> >> Since on IA32 we use 32-bit protected flat model and paging disabled >> (OK?), I wasn't able to validate the paging modes other than 4-level >> paging mode in X64. The memory validation code I wrote is heavily based >> upon what I read from Intel SDM Vol 3A manual. >> >> If you do have any idea on how to validate it -- whether it's a PoC or >> test code -- please let me know, and then I validate it. >> >> Thanks again for your review! >> >> Paulo >> >> > >> > Thank you >> > Yao Jiewen >> > >> >> -----Original Message----- >> >> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of >> Yao, >> >> Jiewen >> >> Sent: Thursday, January 4, 2018 9:36 AM >> >> To: Paulo Alcantara ; edk2-devel@lists.01.org >> >> Cc: Laszlo Ersek ; Dong, Eric >> >> Subject: Re: [edk2] [RFC v4 4/6] UefiCpuPkg/CpuExceptionHandlerLib: Add >> >> helper to valid memory addresses >> >> >> >> Some suggestion: >> >> >> >> 1) I am not sure if it is proper to use ASSERT in an exception handler, because >> we >> >> know something is wrong. >> >> >> >> ASSERT ((PhysicalAddress & (sizeof (*Pml4TableEntry) - 1)) == 0); >> >> >> >> I suggest we just do the check, and return FALSE, if the prerequisite is not >> >> satisfied. >> >> >> >> 2) Can we use meaningful definition for BIT0, BIT7? >> >> >> >> if ((*Pml4TableEntry & BIT0) == 0) { >> >> if ((*PageDirPtrTableEntry & BIT7) != 0) { >> >> >> >> 3) I am not sure if I understand below code. >> >> >> >> PhysicalAddress = (UINT64)Cr3 & (((1ULL << MaxPhyAddrBits) - 1) << 12); >> >> PhysicalAddress = *Pml4TableEntry & (((1ULL << MaxPhyAddrBits) - 1) << >> 12); >> >> PhysicalAddress = *PageDirPtrTableEntry & (((1ULL << MaxPhyAddrBits) - >> 1) >> >> << 12); >> >> PhysicalAddress = *PageDirEntry & (((1ULL << MaxPhyAddrBits) - 1) << >> 12); >> >> >> >> If MaxPhyAddrBits is 48, you will get "Cr3 & 0x0FFFFFFFFFFFF000". Is that >> what >> >> you want? I think we need "Cr3 & 0x0000FFFFFFFFF000" >> >> Should it be: PhysicalAddress = (UINT64)Cr3 & ((1ULL << MaxPhyAddrBits) - 1) >> & >> >> (~0xFFF); >> >> >> >> 4) Can we use a more readable way to below? Personally, I do not suggest >> "<< 3", >> >> which is just the index calculation. >> >> >> >> PhysicalAddress = (UINT64)Cr3 & (((1ULL << MaxPhyAddrBits) - 1) << 12); >> >> PhysicalAddress |= (((UINT64)LinearAddress >> 39) & 0x1FF) << 3; >> >> Pml4TableEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> PhysicalAddress = *Pml4TableEntry & (((1ULL << MaxPhyAddrBits) - 1) << >> 12); >> >> >> >> For example: >> >> PhysicalAddress = (UINT64)Cr3 & ((1ULL << MaxPhyAddrBits) - 1) & >> (~0xFFF); >> >> Pml4TableEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> Index= (UINTN)(((UINT64)LinearAddress >> 39) & 0x1FF); >> >> PhysicalAddress = Pml4TableEntry[Index] & ((1ULL << MaxPhyAddrBits) - 1) >> & >> >> (~0xFFF); >> >> >> >> >> >> >> >> Thank you >> >> Yao Jiewen >> >> >> >> >> >> > -----Original Message----- >> >> > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of >> >> Paulo >> >> > Alcantara >> >> > Sent: Friday, December 29, 2017 12:40 PM >> >> > To: edk2-devel@lists.01.org >> >> > Cc: Laszlo Ersek ; Dong, Eric >> >> > Subject: [edk2] [RFC v4 4/6] UefiCpuPkg/CpuExceptionHandlerLib: Add >> helper >> >> to >> >> > valid memory addresses >> >> > >> >> > Introduce IsLinearAddressValid() function that will be used for >> >> > validating memory addresses that would get dereferenced during stack >> >> > traces in IA32 and X64 CPU exceptions. >> >> > >> >> > Contributed-under: TianoCore Contribution Agreement 1.1 >> >> > Cc: Eric Dong >> >> > Cc: Laszlo Ersek >> >> > Requested-by: Brian Johnson >> >> > Requested-by: Jiewen Yao >> >> > Signed-off-by: Paulo Alcantara >> >> > --- >> >> > UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c | >> 382 >> >> > ++++++++++++++++++++ >> >> > UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h | >> >> 16 + >> >> > 2 files changed, 398 insertions(+) >> >> > >> >> > diff --git >> >> > a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c >> >> > b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c >> >> > index 867c5c01d6..52b3eb1463 100644 >> >> > --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c >> >> > +++ >> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.c >> >> > @@ -14,6 +14,9 @@ >> >> > >> >> > #include "CpuExceptionCommon.h" >> >> > >> >> > +#include >> >> > +#include >> >> > + >> >> > // >> >> > // Error code flag indicating whether or not an error code will be >> >> > // pushed on the stack if an exception occurs. >> >> > @@ -194,3 +197,382 @@ GetPdbFileName ( >> >> > } >> >> > } >> >> > } >> >> > + >> >> > +/** >> >> > + Check if a linear address is valid by walking the page tables in 4-level >> >> > + paging mode. >> >> > + >> >> > + @param[in] Cr3 CR3 control register. >> >> > + @param[in] MaxPhyAddrBits MAXPHYADDRBITS bits. >> >> > + @param[in] LinearAddress Linear address to be checked. >> >> > +**/ >> >> > +STATIC >> >> > +BOOLEAN >> >> > +Do4LevelPagingModeCheck ( >> >> > + IN UINTN Cr3, >> >> > + IN UINT8 MaxPhyAddrBits, >> >> > + IN UINTN LinearAddress >> >> > + ) >> >> > +{ >> >> > + UINT64 PhysicalAddress; >> >> > + UINT64 *Pml4TableEntry; >> >> > + UINT64 *PageDirPtrTableEntry; >> >> > + UINT64 *PageDirEntry; >> >> > + UINT64 *PageTableEntry; >> >> > + >> >> > + // >> >> > + // In 4-level paging mode, linear addresses are 48 bits wide >> >> > + // >> >> > + if ((UINT64)LinearAddress > (1ULL << 48) - 1) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PML4E >> >> > + // >> >> > + PhysicalAddress = (UINT64)Cr3 & (((1ULL << MaxPhyAddrBits) - 1) << >> 12); >> >> > + PhysicalAddress |= (((UINT64)LinearAddress >> 39) & 0x1FF) << 3; >> >> > + >> >> > + ASSERT ((PhysicalAddress & (sizeof (*Pml4TableEntry) - 1)) == 0); >> >> > + >> >> > + Pml4TableEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check if a PDPTE is present >> >> > + // >> >> > + if ((*Pml4TableEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PDPTE >> >> > + // >> >> > + PhysicalAddress = *Pml4TableEntry & (((1ULL << MaxPhyAddrBits) - 1) >> << >> >> > 12); >> >> > + PhysicalAddress |= (((UINT64)LinearAddress >> 30) & 0x1FF) << 3; >> >> > + >> >> > + ASSERT ((PhysicalAddress & (sizeof (*PageDirPtrTableEntry) - 1)) == 0); >> >> > + >> >> > + PageDirPtrTableEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check whether a PDPTE or 1GiB page entry is present >> >> > + // >> >> > + if ((*PageDirPtrTableEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Check if PDPTE maps an 1GiB page >> >> > + // >> >> > + if ((*PageDirPtrTableEntry & BIT7) != 0) { >> >> > + return TRUE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PDE >> >> > + // >> >> > + PhysicalAddress = *PageDirPtrTableEntry & (((1ULL << MaxPhyAddrBits) >> - >> >> 1) >> >> > << >> >> > + 12); >> >> > + PhysicalAddress |= (((UINT64)LinearAddress >> 21) & 0x1FF) << 3; >> >> > + >> >> > + ASSERT ((PhysicalAddress & (sizeof (*PageDirEntry) - 1)) == 0); >> >> > + >> >> > + PageDirEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check whether a PDE or a 2MiB page entry is present >> >> > + // >> >> > + if ((*PageDirEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Check if PDE maps a 2MiB page >> >> > + // >> >> > + if ((*PageDirEntry & BIT7) != 0) { >> >> > + return TRUE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PTE >> >> > + // >> >> > + PhysicalAddress = *PageDirEntry & (((1ULL << MaxPhyAddrBits) - 1) << >> >> 12); >> >> > + PhysicalAddress |= (((UINT64)LinearAddress >> 12) & 0x1FF) << 3; >> >> > + >> >> > + ASSERT ((PhysicalAddress & (sizeof (*PageTableEntry) - 1)) == 0); >> >> > + >> >> > + PageTableEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check if PTE maps a 4KiB page >> >> > + // >> >> > + if ((*PageTableEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + return TRUE; >> >> > +} >> >> > + >> >> > +/** >> >> > + Check if a linear address is valid by walking the page tables in 32-bit >> paging >> >> > + mode. >> >> > + >> >> > + @param[in] Cr3 CR3 control register. >> >> > + @param[in] Cr4 CR4 control register. >> >> > + @param[in] LinearAddress Linear address to be checked. >> >> > +**/ >> >> > +STATIC >> >> > +BOOLEAN >> >> > +Do32BitPagingModeCheck ( >> >> > + IN UINTN Cr3, >> >> > + IN UINTN Cr4, >> >> > + IN UINTN LinearAddress >> >> > + ) >> >> > +{ >> >> > + UINT64 PhysicalAddress; >> >> > + UINT32 *PageDirEntry; >> >> > + UINT32 *PageTableEntry; >> >> > + >> >> > + if (LinearAddress > MAX_UINT32) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PDE >> >> > + // >> >> > + PhysicalAddress = (UINT32)Cr3 & (((1ULL << 20) - 1) << 12); >> >> > + PhysicalAddress |= (((UINT32)LinearAddress >> 22) & 0x3FF) << 2; >> >> > + >> >> > + ASSERT ((PhysicalAddress & (sizeof (*PageDirEntry) - 1)) == 0); >> >> > + >> >> > + PageDirEntry = (UINT32 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check whether a PTE or a 4MiB page is present >> >> > + // >> >> > + if ((*PageDirEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Check if PDE maps a 4MiB page >> >> > + // >> >> > + if ((Cr4 & BIT4) != 0 && (*PageDirEntry & BIT7) != 0) { >> >> > + return TRUE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PTE >> >> > + // >> >> > + PhysicalAddress = *PageDirEntry & (((1ULL << 20) - 1) << 12); >> >> > + PhysicalAddress |= (((UINT32)LinearAddress >> 12) & 0x3FF) << 2; >> >> > + >> >> > + ASSERT ((PhysicalAddress & (sizeof (*PageTableEntry) - 1)) == 0); >> >> > + >> >> > + PageTableEntry = (UINT32 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check if PTE maps a 4KiB page >> >> > + // >> >> > + if ((*PageTableEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + return TRUE; >> >> > +} >> >> > + >> >> > +/** >> >> > + Check if a linear address is valid by walking the page tables in PAE paging >> >> > + mode. >> >> > + >> >> > + @param[in] Cr3 CR3 control register. >> >> > + @param[in] MaxPhyAddrBits MAXPHYADDRBITS bits. >> >> > + @param[in] LinearAddress Linear address to be checked. >> >> > +**/ >> >> > +STATIC >> >> > +BOOLEAN >> >> > +DoPAEPagingModeCheck ( >> >> > + IN UINTN Cr3, >> >> > + IN UINT8 MaxPhyAddrBits, >> >> > + IN UINTN LinearAddress >> >> > + ) >> >> > +{ >> >> > + UINT64 PhysicalAddress; >> >> > + UINT64 *PageDirPtrTableEntry; >> >> > + UINT64 *PageDirEntry; >> >> > + UINT64 *PageTableEntry; >> >> > + >> >> > + if (LinearAddress > MAX_UINT32) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PDPTE >> >> > + // >> >> > + PhysicalAddress = (UINT32)Cr3 >> 5; >> >> > + >> >> > + // >> >> > + // Select PDPTE register >> >> > + // >> >> > + PhysicalAddress += >> >> > + ((UINT32)LinearAddress >> 30) * sizeof (*PageDirPtrTableEntry); >> >> > + >> >> > + PageDirPtrTableEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check if PDE is present >> >> > + // >> >> > + if ((*PageDirPtrTableEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + PhysicalAddress = *PageDirPtrTableEntry & (((1ULL << MaxPhyAddrBits) >> - >> >> 1) >> >> > << >> >> > + 12); >> >> > + PhysicalAddress |= ((LinearAddress >> 21) & 0x1FF) << 3; >> >> > + ASSERT ((PhysicalAddress & (sizeof (*PageDirEntry) - 1)) == 0); >> >> > + >> >> > + PageDirEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check whether a PTE or a 2MiB page is present >> >> > + // >> >> > + if ((*PageDirEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Check if PDE maps a 2MiB page >> >> > + // >> >> > + if ((*PageDirEntry & BIT7) != 0) { >> >> > + return TRUE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Calculate physical address of PTE >> >> > + // >> >> > + PhysicalAddress = *PageDirEntry & (((1ULL << MaxPhyAddrBits) - 1) << >> >> 12); >> >> > + PhysicalAddress |= ((LinearAddress >> 12) & 0x1FF) << 3; >> >> > + ASSERT ((PhysicalAddress & (sizeof (*PageTableEntry) - 1)) == 0); >> >> > + >> >> > + PageTableEntry = (UINT64 *)(UINTN)PhysicalAddress; >> >> > + >> >> > + // >> >> > + // Check if PTE maps a 4KiB page >> >> > + // >> >> > + if ((*PageTableEntry & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + return TRUE; >> >> > +} >> >> > + >> >> > +/** >> >> > + Check if a linear address is valid. >> >> > + >> >> > + @param[in] Cr0 CR0 control register. >> >> > + @param[in] Cr3 CR3 control register. >> >> > + @param[in] Cr4 CR4 control register. >> >> > + @param[in] LinearAddress Linear address to be checked. >> >> > +**/ >> >> > +BOOLEAN >> >> > +IsLinearAddressValid ( >> >> > + IN UINTN Cr0, >> >> > + IN UINTN Cr3, >> >> > + IN UINTN Cr4, >> >> > + IN UINTN LinearAddress >> >> > + ) >> >> > +{ >> >> > + UINT32 Eax; >> >> > + UINT32 Edx; >> >> > + UINT8 MaxPhyAddrBits; >> >> > + MSR_IA32_EFER_REGISTER Msr; >> >> > + BOOLEAN AddressValid; >> >> > + >> >> > + // >> >> > + // Check for valid input parameters >> >> > + // >> >> > + if (Cr0 == 0 || Cr4 == 0 || LinearAddress == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Check if paging is disabled >> >> > + // >> >> > + if ((Cr0 & BIT31) == 0) { >> >> > + // >> >> > + // If CR4.PAE bit is set, then the linear (or physical) address supports >> >> > + // only up to 36 bits. >> >> > + // >> >> > + if (((Cr4 & BIT5) != 0 && (UINT64)LinearAddress > 0xFFFFFFFFFULL) >> || >> >> > + LinearAddress > 0xFFFFFFFF) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + return TRUE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Paging can be enabled only if CR0.PE bit is set >> >> > + // >> >> > + if ((Cr0 & BIT0) == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // CR3 register cannot be zero if paging is enabled >> >> > + // >> >> > + if (Cr3 == 0) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + // >> >> > + // Get MAXPHYADDR bits >> >> > + // >> >> > + AsmCpuid (0x80000000, &Eax, NULL, NULL, NULL); >> >> > + if (Eax >= 0x80000008) { >> >> > + AsmCpuid (0x80000008, &Eax, NULL, NULL, NULL); >> >> > + MaxPhyAddrBits = (UINT8)Eax; >> >> > + } else { >> >> > + AsmCpuid (1, NULL, NULL, NULL, &Edx); >> >> > + if ((Edx & BIT6) != 0) { >> >> > + MaxPhyAddrBits = 36; >> >> > + } else { >> >> > + MaxPhyAddrBits = 32; >> >> > + } >> >> > + } >> >> > + >> >> > + ASSERT (MaxPhyAddrBits > 0); >> >> > + >> >> > + AddressValid = FALSE; >> >> > + >> >> > + // >> >> > + // check if CR4.PAE bit is not set >> >> > + // >> >> > + if ((Cr4 & BIT5) == 0) { >> >> > + // >> >> > + // Check if linear address is valid in 32-bit paging mode >> >> > + // >> >> > + AddressValid = Do32BitPagingModeCheck (Cr3, Cr4, LinearAddress); >> >> > + } else { >> >> > + if (MaxPhyAddrBits > 52) { >> >> > + return FALSE; >> >> > + } >> >> > + >> >> > + Msr.Uint64 = AsmReadMsr64 (MSR_IA32_EFER); >> >> > + >> >> > + if (Msr.Bits.LME == 0) { >> >> > + // >> >> > + // Check if linear address is valid in PAE paging mode >> >> > + // >> >> > + AddressValid = DoPAEPagingModeCheck (Cr3, MaxPhyAddrBits, >> >> > LinearAddress); >> >> > + } else { >> >> > + // >> >> > + // Check if linear address is valid in 4-level paging mode >> >> > + // >> >> > + AddressValid = Do4LevelPagingModeCheck (Cr3, MaxPhyAddrBits, >> >> > + LinearAddress); >> >> > + } >> >> > + } >> >> > + >> >> > + return AddressValid; >> >> > +} >> >> > diff --git >> >> > a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h >> >> > b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h >> >> > index ec46c2d9d3..1b51034c25 100644 >> >> > --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h >> >> > +++ >> b/UefiCpuPkg/Library/CpuExceptionHandlerLib/CpuExceptionCommon.h >> >> > @@ -330,5 +330,21 @@ GetPdbFileName ( >> >> > OUT CHAR8 **PdbFileName >> >> > ); >> >> > >> >> > +/** >> >> > + Check if a linear address is valid. >> >> > + >> >> > + @param[in] Cr0 CR0 control register. >> >> > + @param[in] Cr3 CR3 control register. >> >> > + @param[in] Cr4 CR4 control register. >> >> > + @param[in] LinearAddress Linear address to be checked. >> >> > +**/ >> >> > +BOOLEAN >> >> > +IsLinearAddressValid ( >> >> > + IN UINTN Cr0, >> >> > + IN UINTN Cr3, >> >> > + IN UINTN Cr4, >> >> > + IN UINTN LinearAddress >> >> > + ); >> >> > + >> >> > #endif >> >> > >> >> > -- >> >> > 2.14.3 >> >> > >> >> > _______________________________________________ >> >> > edk2-devel mailing list >> >> > edk2-devel@lists.01.org >> >> > https://lists.01.org/mailman/listinfo/edk2-devel >> >> _______________________________________________ >> >> edk2-devel mailing list >> >> edk2-devel@lists.01.org >> >> https://lists.01.org/mailman/listinfo/edk2-devel >> _______________________________________________ >> edk2-devel mailing list >> edk2-devel@lists.01.org >> https://lists.01.org/mailman/listinfo/edk2-devel