UEFI executables that consist of a single read+write+exec PE/COFF section
trigger this message, but such a binary layout isn't actually an error.
The image can be launched alright, only image protection cannot be applied
to it fully.
One example that elicits the message is (some) Linux kernels (with the EFI
stub of course).
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
When attempting to perform page allocations using AllocateAddress, we
fail to check whether the entire region is free before splitting the
region. This may lead to memory being leaked further into the routine,
when it turns out that one of the memory map entries intersected by the
region is already occupied. In this case, prior conversions are not rolled
back.
For instance, starting from this situation
0x000040000000-0x00004007ffff [ConventionalMemory ]
0x000040080000-0x00004009ffff [Boot Data ]
0x0000400a0000-0x000047ffffff [ConventionalMemory ]
a failed EfiLoaderData allocation @ 0x40000000 that covers the BootData
region will fail, but leave the first part of the allocation converted,
so we end up with
0x000040000000-0x00004007ffff [Loader Data ]
0x000040080000-0x00004009ffff [Boot Data ]
0x0000400a0000-0x000047ffffff [ConventionalMemory ]
even though the AllocatePages() call returned an error.
So let's check beforehand that AllocateAddress allocations are covered
by a single memory map entry, so that it either succeeds or fails
completely, rather than leaking allocations.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Star Zeng <star.zeng@intel.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=370
Use GLOBAL_REMOVE_IF_UNREFERENCED for some memory profile global variables,
then their symbols could be removed when memory profile is disabled.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=370
Use GLOBAL_REMOVE_IF_UNREFERENCED for some SMRAM profile global variables,
then their symbols could be removed when SMRAM profile is disabled.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
The reason is that we observe that a platform may use same Handler
for different context.
In order to support Unregister such handler, we have to input
context information as well.
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.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>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Architectures such as AArch64 may run the OS with 16 KB or 64 KB sized
pages, and for this reason, the UEFI spec mandates a minimal allocation
granularity of 64 KB for regions that may require different memory
attributes at OS runtime.
So make PeiCore's implementation of AllocatePages () take this into
account as well.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Remove the local definitions for the default and runtime page allocation
granularity macros, and switch to the new MdePkg versions.
Note that this replaces a reference to the 'default' version with the
more correct 'runtime' version, but this matters little in practice.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Remove the local definitions for the default and runtime page allocation
granularity macros, and switch to the new MdePkg versions.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
There are cases that the operands of an expression are all with rank less
than UINT64/INT64 and the result of the expression is explicitly cast to
UINT64/INT64 to fit the target size.
An example will be:
UINT32 a,b;
// a and b can be any unsigned int type with rank less than UINT64, like
// UINT8, UINT16, etc.
UINT64 c;
c = (UINT64) (a + b);
Some static code checkers may warn that the expression result might
overflow within the rank of "int" (integer promotions) and the result is
then cast to a bigger size.
The commit refines codes by the following rules:
1). When the expression is possible to overflow the range of unsigned int/
int:
c = (UINT64)a + b;
2). When the expression will not overflow within the rank of "int", remove
the explicit type casts:
c = a + b;
3). When the expression will be cast to pointer of possible greater size:
UINT32 a,b;
VOID *c;
c = (VOID *)(UINTN)(a + b); --> c = (VOID *)((UINTN)a + b);
4). When one side of a comparison expression contains only operands with
rank less than UINT32:
UINT8 a;
UINT16 b;
UINTN c;
if ((UINTN)(a + b) > c) {...} --> if (((UINT32)a + b) > c) {...}
For rule 4), if we remove the 'UINTN' type cast like:
if (a + b > c) {...}
The VS compiler will complain with warning C4018 (signed/unsigned
mismatch, level 3 warning) due to promoting 'a + b' to type 'int'.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.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 creating page tables.
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: Star Zeng <star.zeng@intel.com>
This implements a DXE memory protection policy that ensures that regions
that don't require executable permissions are mapped with the non-exec
attribute set.
First of all, it iterates over all entries in the UEFI memory map, and
removes executable permissions according to the configured DXE memory
protection policy, as recorded in PcdDxeNxMemoryProtectionPolicy.
Secondly, it sets or clears the non-executable attribute when allocating
or freeing pages, both for page based or pool based allocations.
Note that this complements the image protection facility, which applies
strict permissions to BootServicesCode/RuntimeServicesCode regions when
the section alignment allows it. The memory protection configured by this
patch operates on non-code regions only.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
In preparation of adding memory permission attribute management to
the pool allocator, split off the locking of the pool metadata into
a separate lock. This is an improvement in itself, given that pool
allocations can only interfere with the page allocation bookkeeping
if pool pages are allocated or released. But it is also required to
ensure that the permission attribute management does not deadlock,
given that it may trigger page table splits leading to additional
page tables being allocated.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Ensure that any memory allocated for PE/COFF images is identifiable as
a boot services code region, so that we know it requires its executable
permissions to be preserved when we tighten mapping permissions later on.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Instead of assuming that a PE/COFF section of type EFI_IMAGE_SCN_CNT_CODE
can always be mapped read-only, classify a section as a code section only
if it has the executable attribute set and the writable attribute cleared.
This adheres more closely to the PE/COFF spec, and avoids issues with
Linux OS loaders that may consist of a single read/write/execute section.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
1) SmmCore maintains the root SMI handler and NULL SMI handler
database.
2) SmmCore consumes PcdSmiHandlerProfilePropertyMask to decide
if SmmCore need support SMI handler profile.
If SMI handler profile is supported, the SmmCore installs
SMI handler profile protocol and SMI handler profile
communication handler.
3) SMI handler profile protocol will record the hardware SMI
handler profile registered by SmmChildDispatcher.
4) SMI handler profile communication handler will return all
SMI handler profile info (NULL SMI handler, GUID SMI handler,
and hardware SMI handler)
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>
Reviewed-by: Star Zeng <star.zeng@intel.com>
If the UEFI image is page aligned, the image code section is set to read
only and the image data section is set to non-executable.
1) This policy is applied for all UEFI image including boot service driver,
runtime driver or application.
2) This policy is applied only if the UEFI image meets the page alignment
requirement.
3) This policy is applied only if the Source UEFI image matches the
PcdImageProtectionPolicy definition.
4) This policy is not applied to the non-PE image region.
The DxeCore calls CpuArchProtocol->SetMemoryAttributes() to protect
the image. If the CpuArch protocol is not installed yet, the DxeCore
enqueues the protection request. Once the CpuArch is installed, the
DxeCore dequeues the protection request and applies policy.
Once the image is unloaded, the protection is removed automatically.
The UEFI runtime image protection is teared down at ExitBootServices(),
the runtime image code relocation need write code segment at
SetVirtualAddressMap(). We cannot assume OS/Loader has taken over
page table at that time.
NOTE: It is per-requisite that code section and data section
should not be not merged. That is same criteria for SMM/runtime driver.
We are not able to detect during BIOS boot, because
we can only get LINK warning below:
"LINK : warning LNK4254: section '.data' (C0000040) merged into
'.text' (60000020) with different attributes"
But final attribute in PE code section is same.
Cc: Star Zeng <star.zeng@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael 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>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
If GUIDED section authentication has EFI_AUTH_STATUS_NOT_TESTED, its
matched extraction ppi may not be installed. So, don't cache its data.
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
When PEIM is security violation, its matched extraction ppi may not be
installed. So, its PeimNeedingDispatch will still reset to TRUE.
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
When gDS->SetMemorySpaceCapabilities() is called,
current DXE core will sync all GCD attributes to memory map
attributes, including RUNTIME attributes.
It is wrong, because RUNTIME attributes should be set for
runtime memory only.
This fix clears the RUNTIME attributes before convert to UEFI
memory map. So that the UEFI memory map is good after
gDS->SetMemorySpaceCapabilities() is called.
Cc: Star Zeng <star.zeng@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
If a BaseAddress of NULL is passed into DXE Core services
CoreAllocateIoSpace() or CoreAllocateMemorySpace(), and
DEBUG() messages are enabled, then a NULL pointer reference
is made. The parameter check for BaseAddress is performed
in the function CoreAllocateSpace() after the DEBUG()
messages. A check is added in the DEBUG() messages to
prevent the NULL pointer reference.
This issue was found with PI SCTs with DEBUG messages
enabled in the DXE Core.
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Feng Tian <feng.tian@Intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
PiSmmIpl records LoadModuleAtFixAddressSmramBase in LMFAConfigurationTable.
Update PiSmmCore to directly get the address from this system table.
Cc: Star Zeng <star.zeng@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Allocate the additional Smram range to describe the reserved smram for
SMM core and driver when LMFA feature is enabled.
Cc: Star Zeng <star.zeng@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
https://bugzilla.tianocore.org/show_bug.cgi?id=278
Zero memory address or zero number pages are invalid to SmmFreePages().
Cc: Star Zeng <star.zeng@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
EFI_PAGES_TO_SIZE only handles UINTN, so we use EfiPagesToSize
to handle UINT64.
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>
Regression-tested-by: 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>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Current memory attribute table implementation will only mark PE code
to be EfiRuntimeServicesCode, and mark rest to be EfiRuntimeServicesData.
However, there might be a case that a SMM code wants to allocate
EfiRuntimeServicesCode explicitly to let page table protect this region
to be read only. It is unsupported.
This patch enhances the current solution so that MemoryAttributeTable
does not touch non PE image record.
Only the PE image region is forced to be EfiRuntimeServicesCode for
code and EfiRuntimeServicesData for data.
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>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
PiSmmCore supports page level protection based upon the Memory Type
(EfiRuntimeServicesCode/EfiRuntimeServicesData) and PE image.
However, the Memory Type information is ignored in AllocatePool().
If a caller calls AllocatePool with EfiRuntimeServicesCode,
the final memory is still allocated as EfiRuntimeServicesData.
This patch supports AllocatePool with EfiRuntimeServicesCode.
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>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Add the comments to describe Free and Allocated SMRAM are added separately.
Cc: Star Zeng <star.zeng@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Make SetPeiServicesTablePointer() earlier than ProcessLibraryConstructorList()
so the constructor() function can get the correct pei service table pointer.
https://bugzilla.tianocore.org/show_bug.cgi?id=238
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
gSmmCorePrivate->CommunicationBuffer and gSmmCorePrivate->BufferSize locate at
runtime memory region. That means they could be modified by non-SMM code during
runtime.
We should cache them into SMM local variables before we verify them. After
verification, we should use the cached ones directly instead of the ones in
gSmmCorePrivate.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
The SMM memory attribute table concept is similar to UEFI
memory attribute table.
The new file MdeModulePkg/Core/PiSmmCore/MemoryAttributesTable.c
and the new code in MdeModulePkg/Core/PiSmmCore/Page.c
are based on the algorithms and implementation from
MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c
and MdeModulePkg/Core/Dxe/Mem/Page.c.
These new components are based on the Memory Attributes Table
feature from the UEFI Specification and the existing DXE Core
implementation that supports that feature.
This SMM MemoryAttributes table is produced at SmmEndOfDxe event.
So that the consumer (PiSmmCpu) may consult this table
to set memory attribute in page table.
This patch also installs LoadedImage protocol to SMM
protocol database, so that the SMM image info can be
got easily to construct the PiSmmMemoryAttributes table.
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>
PeiServicesAllocatePages () will output sizeof (EFI_PHYSICAL_ADDRESS) value.
IdtTableForX64 is sizeof (UINTN) local variable. It will overwrite other local
variable.
This issue is found when we dump BaseOfStack value.
Cc: Feng Tian <feng.tian@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Dump new stack base and size information could help developer to narrow down
stack crash issue.
Cc: Feng Tian <feng.tian@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Instead of comparing a GUID with gZeroGuid via the CompareGuid API, the
commit uses the IsZeroGuid API to check if the given GUID is a zero GUID.
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Feng Tian <feng.tian@Intel.com>
Code logic ensures that the pointer 'DriverInfoData' will not be NULL when
it is used.
Add ASSERT as warning for case that will not happen.
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
- abstrated to abstracted
- accessibla to accessible
- addres to address
- apropriate to appropriate
- arry to array
- availabe to available
- avaliable to available
- becasue to because
- correponding to corresponding
- etablished to established
- exeuction to execution
- extensiable to extensible
- fileds to fields
- loadding to loading
- ptototypes to prototypes
- prococol protocol
- requried to required
- resoruce to resource
- runing to running
- uild to build
Cc: Star Zeng <star.zeng@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Laszlo Ersek
Ard Biesheuvel
Star Zeng
Jiewen Yao
Bi, Dandan
Hao Wu
Fu Siyuan
Leo Duran
Liming Gao
Michael Kinney
Jeff Fan
Gary Lin
Marvin Haeuser
Giri P Mudusuru