Root cause:
1. Before DisableReadonlyPageWriteProtect() is called, the return
address (#1) is pushed in shadow stack.
2. CET is disabled.
3. DisableReadonlyPageWriteProtect() returns to #1.
4. Page table is modified.
5. EnableReadonlyPageWriteProtect() is called, but the return
address (#2) is not pushed in shadow stack.
6. CET is enabled.
7. EnableReadonlyPageWriteProtect() returns to #2.
#CP exception happens because the actual return address (#2)
doesn't match the return address stored in shadow stack (#1).
Analysis:
Shadow stack will stop update after CET disable (DisableCet() in
DisableReadOnlyPageWriteProtect), but normal smi stack will be
continue updated with the function called and return
(DisableReadOnlyPageWriteProtect & EnableReadOnlyPageWriteProtect),
thus leading stack mismatch after CET re-enabled (EnableCet() in
EnableReadOnlyPageWriteProtect).
According SDM Vol 3, 6.15-Control Protection Exception:
Normal smi stack and shadow stack must be matched when CET enable,
otherwise CP Exception will happen, which is caused by a near RET
instruction.
CET is disabled in DisableCet(), while can be enabled in
EnableCet(). This way won't cause the problem because they are
implemented in a way that return address of DisableCet() is
poped out from shadow stack (Incsspq performs a pop to increases
the shadow stack) and EnableCet() doesn't use "RET" but "JMP" to
return to caller. So calling EnableCet() and DisableCet() doesn't
have the same issue as calling DisableReadonlyPageWriteProtect()
and EnableReadonlyPageWriteProtect().
With above root cause & analysis, define below 2 macros instead of
functions for WP & CET operation:
WRITE_UNPROTECT_RO_PAGES (Wp, Cet)
WRITE_PROTECT_RO_PAGES (Wp, Cet)
Because DisableCet() & EnableCet() must be in the same function
to avoid shadow stack and normal SMI stack mismatch.
Note: WRITE_UNPROTECT_RO_PAGES () must be called pair with
WRITE_PROTECT_RO_PAGES () in same function.
Change-Id: I4e126697efcd8dbfb4887da034d8691bfca969e3
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Zeng Star <star.zeng@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Remove unnecessary function SetNotPresentPage(). We can directly
use ConvertMemoryPageAttributes to set a range to non-present.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
This commit is code refinement to current smm pagetable generation
code. Add a new GenSmmPageTable() API to create smm page table
based on the PageTableMap() API in CpuPageTableLib. Caller only
needs to specify the paging mode and the PhysicalAddressBits to map.
This function can be used to create both IA32 pae paging and X64
5level, 4level paging.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Clear CR0.WP before modify smm page table. Currently, there is
an assumption that smm pagetable is always RW before ReadyToLock.
However, when AMD SEV is enabled, FvbServicesSmm driver calls
MemEncryptSevClearMmioPageEncMask to clear AddressEncMask bit
in smm page table for this range:
[PcdOvmfFdBaseAddress,PcdOvmfFdBaseAddress+PcdOvmfFirmwareFdSize]
If page slpit happens in this process, new memory for smm page
table is allocated. Then the newly allocated page table memory
is marked as RO in smm page table in this FvbServicesSmm driver,
which may lead to PF if smm code doesn't clear CR0.WP before
modify smm page table when ReadyToLock.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Add two functions to disable/enable CR0.WP. These two unctions
will also be used in later commits. This commit doesn't change any
functionality.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
In PiSmmCpuDxeSmm code, SetMemMapAttributes() marks memory ranges
in SmmMemoryAttributesTable to RO/NX. There may exist non-present
range in these memory ranges. Set other attributes for a non-present
range is not permitted in CpuPageTableMapLib. So add code to handle
this case. Only map the present ranges in SmmMemoryAttributesTable
to RO or NX.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
In ConvertMemoryPageAttributes() function, when clear RP for a
specific range [BaseAddress, BaseAddress + Length], it means to
set the present bit to 1 and assign default value for other
attributes in page table. The default attributes for the input
specific range are NX disabled and ReadOnly. If there is existing
present range in [BaseAddress, BaseAddress + Length] and the
attributes are not NX disabled or not ReadOnly, then output the
DEBUG message to indicate that the NX and ReadOnly attributes of
the existing present range are modified in the function.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Simplify the ConvertMemoryPageAttributes API to convert paging
attribute by CpuPageTableLib. In the new API, it calls
PageTableMap() to update the page attributes of a memory range.
With the PageTableMap() API in CpuPageTableLib, we can remove
the complicated page table manipulating code.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
When setting new page table pool to RO, only disable/enable WP when
Cr0.WP has been set to 1 to fix potential PF caused by b822be1a20
(UefiCpuPkg/PiSmmCpuDxeSmm: Introduce page table pool mechanism).
With previous code, if someone want to modify the page table and
Cr0.WP has been cleared before modify page table, Cr0.WP may be set
to 1 again since new pool may be generated during this process
Then PF fault may happens.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Simplify the code to set memory used by smm page table as RO.
Since memory used by smm page table are in PageTablePool list,
we only need to set all PageTablePool as ReadOnly in smm page
table itself. Also, we only need to flush tlb once after
setting all page table pool as Read Only.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Introduce page table pool mechanism for smm page table to simplify
page table memory management and protection. This mechanism has been
used in DxeIpl. The basic idea is to allocate a bunch of continuous
pages of memory in advance, and all future page tables consumption
will happen in those pool instead of system memory.
Since we have centralized page tables, we only need to mark all page
table pools as RO, instead of searching page table memory layer by
layer in smm page table. Once current page table pool has been used
up, another memory pool will be allocated and the new pool will also
be set as RO if current page table memory has been marked as RO.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
This patch is code refactoring and doesn't change any functionality.
Remove mInternalCr3 in PiSmmCpuDxe pagetable related code. In previous
code, mInternalCr3 is used to pass address of page table which is
different from Cr3 register in different level of SetMemoryAttributes
function. Now remove it and pass the page table base address from the
root function parameter to simplify the code logic.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
This patch is code refactoring and doesn't change any functionality.
Add a new mIsShadowStack flag to identify whether current memory is
shadow stack. Previous smm code logic regards a RO range as shadow
stack and set the dirty bit in corresponding page table entry if
mInternalCr3 is not 0, which may be confusing.
Signed-off-by: Dun Tan <dun.tan@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3737
Apply uncrustify changes to .c/.h files in the UefiCpuPkg package
Cc: Andrew Fish <afish@apple.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3760
Update all use of ', OPTIONAL' to ' OPTIONAL,' for function params.
Cc: Andrew Fish <afish@apple.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
When trying to get page table base, if mInternalCr3 is zero, it will use
the page table from CR3, and reflect the page table depth by CR4 LA57 bit.
If mInternalCr3 is non zero, it will use the page table from mInternalCr3
and reflect the page table depth of mInternalCr3 at same time.
In the case of X64, we use m5LevelPagingNeeded to reflect the depth of
the page table. And in the case of IA32, it will not the page table depth
information.
This patch is a bug fix when enable CET feature with 5 level paging.
The SMM page tables are allocated / initialized in PiCpuSmmEntry().
When CET is enabled, PiCpuSmmEntry() must further modify the attribute of
shadow stack pages. This page table is not set to CR3 in PiCpuSmmEntry().
So the page table base address is set to mInternalCr3 for modifty the
page table attribute. It could not use CR4 LA57 bit to reflect the
page table depth for mInternalCr3.
So we create a architecture-specific implementation GetPageTable() with
2 output parameters. One parameter is used to output the page table
address. Another parameter is used to reflect if it is 5 level paging
or not.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3015
Signed-off-by: Sheng Wei <w.sheng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Change the variable name from mInternalGr3 to mInternalCr3.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3015
Signed-off-by: Sheng Wei <w.sheng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Fix various typos in comments and documentation.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Antoine Coeur <coeur@gmx.fr>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Signed-off-by: Philippe Mathieu-Daude <philmd@redhat.com>
Message-Id: <20200207010831.9046-78-philmd@redhat.com>
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1946
The patch changes SMM environment to use 5 level paging when CPU
supports it.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
(cherry picked from commit 7365eb2c8c)
This reverts commit 7365eb2c8c.
Commit
7c5010c7f8 MdePkg/BaseLib.h: Update IA32_CR4 structure for 5-level paging
technically breaks the EDKII development process documented in
https://github.com/tianocore/tianocore.github.io/wiki/EDK-II-Development-Process
and Maintainers.txt in EDKII repo root directory.
The voilation is commit 7c5010c7f8 doesn't have a Reviewed-by or
Acked-by from MdePkg maintainers.
In order to revert 7c5010c7f8, 7365eb2c8 needs to revert first otherwise
simply reverting 7c5010c7f8 will cause build break.
Signed-off-by: Ray Ni <ray.ni@intel.com>
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1946
The patch changes SMM environment to use 5 level paging when CPU
supports it.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1521
We scan the SMM code with ROPgadget.
http://shell-storm.org/project/ROPgadget/https://github.com/JonathanSalwan/ROPgadget/tree/master
This tool reports the gadget in SMM driver.
This patch enabled CET ShadowStack for X86 SMM.
If CET is supported, SMM will enable CET ShadowStack.
SMM CET will save the OS CET context at SmmEntry and
restore OS CET context at SmmExit.
Test:
1) test Intel internal platform (x64 only, CET enabled/disabled)
Boot test:
CET supported or not supported CPU
on CET supported platform
CET enabled/disabled
PcdCpuSmmCetEnable enabled/disabled
Single core/Multiple core
PcdCpuSmmStackGuard enabled/disabled
PcdCpuSmmProfileEnable enabled/disabled
PcdCpuSmmStaticPageTable enabled/disabled
CET exception test:
#CF generated with PcdCpuSmmStackGuard enabled/disabled.
Other exception test:
#PF for normal stack overflow
#PF for NX protection
#PF for RO protection
CET env test:
Launch SMM in CET enabled/disabled environment (DXE) - no impact to DXE
The test case can be found at
https://github.com/jyao1/SecurityEx/tree/master/ControlFlowPkg
2) test ovmf (both IA32 and X64 SMM, CET disabled only)
test OvmfIa32/Ovmf3264, with -D SMM_REQUIRE.
qemu-system-x86_64.exe -machine q35,smm=on -smp 4
-serial file:serial.log
-drive if=pflash,format=raw,unit=0,file=OVMF_CODE.fd,readonly=on
-drive if=pflash,format=raw,unit=1,file=OVMF_VARS.fd
QEMU emulator version 3.1.0 (v3.1.0-11736-g7a30e7adb0-dirty)
3) not tested
IA32 CET enabled platform
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Yao Jiewen <jiewen.yao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Within function GetUefiMemoryAttributesTable(), add a check to avoid
possible null pointer dereference.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
It treats the UEFI runtime page with EFI_MEMORY_RO attribute as
invalid SMM communication buffer.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
It treats GCD untested memory as invalid SMM
communication buffer.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
AllocateCodePages() is used to allocate buffer for IDT range,
the code pages will be set to RO in SetMemMapAttributes(),
then the code to set IDT range to RO in PatchGdtIdtMap() is
redundant and could be removed.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
When StackGuard is enabled on IA32, the #double fault exception
is reported instead of #page fault.
This issue does not exist on X64, or IA32 without StackGuard.
The fix at e4435f710c was incomplete.
It is because AllocateCodePages() is used to allocate buffer for
GDT and TSS, the code pages will be set to RO in SetMemMapAttributes().
But IA32 Stack Guard need use task switch to switch stack that need
write GDT and TSS, so AllocateCodePages() could not be used.
This patch uses AllocatePages() instead of AllocateCodePages() to
allocate buffer for GDT and TSS if StackGuard is enabled on IA32.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Heap guard makes use of paging mechanism to implement its functionality. But
there's no protocol or library available to change page attribute in SMM mode.
A new protocol gEdkiiSmmMemoryAttributeProtocolGuid is introduced to make it
happen. This protocol provide three interfaces
struct _EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL {
EDKII_SMM_GET_MEMORY_ATTRIBUTES GetMemoryAttributes;
EDKII_SMM_SET_MEMORY_ATTRIBUTES SetMemoryAttributes;
EDKII_SMM_CLEAR_MEMORY_ATTRIBUTES ClearMemoryAttributes;
};
Since heap guard feature need to update page attributes. The page table
should not set to be read-only if heap guard feature is enabled for SMM
mode. Otherwise this feature cannot work.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Suggested-by: Ayellet Wolman <ayellet.wolman@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
https://bugzilla.tianocore.org/show_bug.cgi?id=624 reports
memory protection crash in PiSmmCpuDxeSmm, Ia32 build with
RAM above 4GB (of which 2GB are placed in 64-bit address).
It is because UEFI builds identity mapping page tables,
>4G address is not supported at Ia32 build.
This patch is to get the PhysicalAddressBits that is used
to build in PageTbl.c(Ia32/X64), and use it to check whether
the address is supported or not in ConvertMemoryPageAttributes().
With this patch, the debug messages will be like below.
UefiMemory protection: 0x0 - 0x9F000 Success
UefiMemory protection: 0x100000 - 0x807000 Success
UefiMemory protection: 0x808000 - 0x810000 Success
UefiMemory protection: 0x818000 - 0x820000 Success
UefiMemory protection: 0x1510000 - 0x7B798000 Success
UefiMemory protection: 0x7B79B000 - 0x7E538000 Success
UefiMemory protection: 0x7E539000 - 0x7E545000 Success
UefiMemory protection: 0x7E55A000 - 0x7E61F000 Success
UefiMemory protection: 0x7E62B000 - 0x7F6AB000 Success
UefiMemory protection: 0x7F703000 - 0x7F70B000 Success
UefiMemory protection: 0x7F70F000 - 0x7F778000 Success
UefiMemory protection: 0x100000000 - 0x180000000 Unsupported
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Eric Dong <eric.dong@intel.com>
Originally-suggested-by: Jiewen Yao <jiewen.yao@intel.com>
Reported-by: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
This PCD holds the address mask for page table entries when memory
encryption is enabled on AMD processors supporting the Secure Encrypted
Virtualization (SEV) feature.
The mask is applied when page tables entriees are created or modified.
CC: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Leo Duran <leo.duran@amd.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
This patch sets the normal OS buffer EfiLoaderCode/Data,
EfiBootServicesCode/Data, EfiConventionalMemory, EfiACPIReclaimMemory
to be not present after SmmReadyToLock.
To access these region in OS runtime phase is not a good solution.
Previously, we did similar check in SmmMemLib to help SMI handler
do the check. But if SMI handler forgets the check, it can still
access these OS region and bring risk.
So here we enforce the policy to prevent it happening.
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
This patch fixes https://bugzilla.tianocore.org/show_bug.cgi?id=246
Previously, when SMM exception happens after EndOfDxe,
with StackGuard enabled on IA32, the #double fault exception
is reported instead of #page fault.
Root cause is below:
Current EDKII SMM page protection will lock GDT.
If IA32 stack guard is enabled, the page fault handler will do task switch.
This task switch need write busy flag in GDT, and write TSS.
However, the GDT and TSS is locked at that time, so the
double fault happens.
We decide to not lock GDT for IA32 StackGuard enabled.
This issue does not exist on X64, or IA32 without StackGuard.
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
https://bugzilla.tianocore.org/show_bug.cgi?id=277
Remove dependency on layout of PROCESSOR_SMM_DESCRIPTOR
everywhere possible. The only exception is the standard
SMI entry handler template that is included with the
PiSmmCpuDxeSmm module. This allows an instance of the
SmmCpuFeaturesLib to provide alternate
PROCESSOR_SMM_DESCRIPTOR structure layouts.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
PiSmmCpu driver may split page for page attribute request.
Current logic not only propagates the super page attribute to
the leaf page attribut, but also to the directory page attribute.
However, the later might be wrong because we cannot clear protection
without touching directory page attribute.
The effective protection is the strictest combination
across the levels.
We should always clear protection on directory page and set
protection on leaf page for easy clearing later.
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
When XD is not supported, the BIT63 is reserved.
We should not set BIT63 in the page table.
Test OVMF IA32/IA32X64 with XD enabled/disabled.
Analyzed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
PiSmmCpuDxeSmm consumes SmmAttributesTable and setup page table:
1) Code region is marked as read-only and Data region is non-executable,
if the PE image is 4K aligned.
2) Important data structure is set to RO, such as GDT/IDT.
3) SmmSaveState is set to non-executable,
and SmmEntrypoint is set to read-only.
4) If static page is supported, page table is read-only.
We use page table to protect other components, and itself.
If we use dynamic paging, we can still provide *partial* protection.
And hope page table is not modified by other components.
The XD enabling code is moved to SmiEntry to let NX take effect.
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Jiaxin Wu
Dun Tan
Ray Ni
Michael Kubacki
Michael D Kinney
Sheng Wei
Oleksiy Yakovlev
Antoine Coeur
Jiewen Yao
Hao Wu
Star Zeng
Jian J Wang
Leo Duran