If CET shadows stack feature enabled in SMM and stack switch is enabled.
When code execute from SMM handler to SMM exception, CPU will check SMM
exception shadow stack token busy bit if it is cleared or not.
If it is set, it will trigger #DF exception.
If it is not set, CPU will set the busy bit when enter SMM exception.
So, the busy bit should be cleared when return back form SMM exception to
SMM handler. Otherwise, keeping busy bit 1 will cause to trigger #DF
exception when enter SMM exception next time.
So, we use instruction SAVEPREVSSP, CLRSSBSY and RSTORSSP to clear the
shadow stack token busy bit before RETF instruction in SMM exception.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3192
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>
Cc: Roger Feng <roger.feng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
Add base support to handle #VC exceptions. Update the common exception
handlers to invoke the VmgExitHandleVc () function of the VmgExitLib
library when a #VC is encountered. A non-zero return code will propagate
to the targeted exception handler.
Under SEV-ES, a DR7 read or write intercept generates a #VC exception.
To avoid exception recursion, a #VC exception will not try to read and
push the actual debug registers into the EFI_SYSTEM_CONTEXT_X64 struct
and instead push zeroes. The #VC exception handler does not make use of
the debug registers from the saved context and the exception processing
exit code does not attempt to restore the debug register values.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
.nasm file has been added for X86 arch. .S assembly code
is not required any more.
https://bugzilla.tianocore.org/show_bug.cgi?id=1594
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
NASM has replaced ASM and S files.
1. Remove ASM from all modules expect for the ones in ResetVector directory.
The ones in ResetVector directory are included by Vtf0.nasmb. They are
also nasm style.
2. Remove S files from the drivers only.
3. https://bugzilla.tianocore.org/show_bug.cgi?id=881
After NASM is updated, S files can be removed from Library.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
If Stack Guard is enabled and there's really a stack overflow happened during
boot, a Page Fault exception will be triggered. Because the stack is out of
usage, the exception handler, which shares the stack with normal UEFI driver,
cannot be executed and cannot dump the processor information.
Without those information, it's very difficult for the BIOS developers locate
the root cause of stack overflow. And without a workable stack, the developer
cannot event use single step to debug the UEFI driver with JTAG debugger.
In order to make sure the exception handler to execute normally after stack
overflow. We need separate stacks for exception handlers in case of unusable
stack.
IA processor allows to switch to a new stack during handling interrupt and
exception. But X64 and IA32 provides different ways to make it. X64 provides
interrupt stack table (IST) to allow maximum 7 different exceptions to have
new stack for its handler. IA32 doesn't have IST mechanism and can only use
task gate to do it since task switch allows to load a new stack through its
task-state segment (TSS).
The new API, InitializeCpuExceptionHandlersEx, is implemented to complete
extra initialization for stack switch of exception handler. Since setting
up stack switch needs allocating new memory for new stack, new GDT table
and task-state segment but the initialization method will be called in
different phases which have no consistent way to reserve those memory, this
new API is allowed to pass the reserved resources to complete the extra
works. This is cannot be done by original InitializeCpuExceptionHandlers.
Considering exception handler initialization for MP situation, this new API
is also necessary, because AP is not supposed to allocate memory. So the
memory needed for stack switch have to be reserved in BSP before waking up
AP and then pass them to InitializeCpuExceptionHandlersEx afterwards.
Since Stack Guard feature is available only for DXE phase at this time, the
new API is fully implemented for DXE only. Other phases implement a dummy
one which just calls InitializeCpuExceptionHandlers().
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael Kinney <michael.d.kinney@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: Jeff Fan <vanjeff_919@hotmail.com>
Reviewed-by: Jiewen.yao@intel.com
Use CPUID Leaf 01 to detect support for debug extensions and FXSAVE/FXRESTOR instructions.
Do not enable those features in CR4 if they are not supported.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17221 6f19259b-4bc3-4df7-8a09-765794883524
1. Usage information in INF file comment blocks are either incomplete or incorrect.
This includes usage information for Protocols/PPIs/GUIDs/PCDs/HOBs/Events/BootModes.
The syntax for usage information in comment blocks is defined in the EDK II Module Information (INF) Specification
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Gao, Liming <liming.gao@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15933 6f19259b-4bc3-4df7-8a09-765794883524
2. Updated CPU Exception Handler Library instance according to the new CPU Exception Handler Library class definitions.
3. Updated CPU Exception Handler Library instance to handle the vector attributes defined in PI 1.2.1.
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Hot Tian <hot.tian@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14885 6f19259b-4bc3-4df7-8a09-765794883524
Sheng Wei
Tom Lendacky
Michael D Kinney
Shenglei Zhang
Liming Gao
Jian J Wang
Jeff Fan
vanjeff