Commit Graph

9 Commits

Author SHA1 Message Date
Jason 2aa107c0aa UefiCpuPkg: Replace Opcode with the corresponding instructions.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3790

Replace Opcode with the corresponding instructions.
The code changes have been verified with CompareBuild.py tool, which
can be used to compare the results of two different EDK II builds to
determine if they generate the same binaries.
(tool link: https://github.com/mdkinney/edk2/tree/sandbox/CompareBuild)

Signed-off-by: Jason Lou <yun.lou@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
2022-03-01 01:45:47 +00:00
Tom Lendacky 5277540e37 UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception
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>
2020-08-17 02:46:39 +00:00
Lendacky, Thomas 9378310dd8 UefiCpuPkg/CpuExceptionHandler: Revert CpuExceptionHandler binary patching
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2340

Now that an XCODE5 specific CpuExceptionHandlerLib library is in place,
revert the changes made to the ExceptionHandlerAsm.nasm in commit
2db0ccc2d7 ("UefiCpuPkg: Update CpuExceptionHandlerLib pass XCODE5 tool
chain") so that binary patching of flash code is not performed.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Liming Gao <liming.gao@intel.com>
Acked-by: Bret Barkelew <bret.barkelew@microsoft.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <810f67d8604c054c09d17a22f0bcfaeb41ee8e3b.1588856809.git.thomas.lendacky@amd.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
2020-05-11 19:25:33 +00:00
John E Lofgren f4c898f2b2 UefiCpuPkg/CpuExceptionHandlerLib: Fix split lock
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2150

v4:
The v3 posting didn't do what it promised to do, so do it now for real.

V3 changes:
change to mov instruction (non locking instuction) instead
of xchg to simplify design.

V2 changes:
Add xchg 16 bit instructions to handle sgdt and sidt base
63:48 bits and 47:32 bits.
Add comment to explain why xchg 64bit isnt being used

Split lock happens when a locking instruction is used on mis-aligned data
that crosses two cachelines. If close source platform enables Alignment
Check Exception(#AC), They can hit a double fault due to split lock being
in CpuExceptionHandlerLib.

sigt and sgdt saves 10 bytes to memory, 8 bytes is base and 2 bytes is limit.
The data is mis-aligned, can cross two cacheline, and a xchg
instruction(locking instuction) is being utilize.

Signed-off-by: John E Lofgren <john.e.lofgren@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2019-09-20 14:37:42 +08:00
Michael D Kinney 0acd869796 UefiCpuPkg: Replace BSD License with BSD+Patent License
https://bugzilla.tianocore.org/show_bug.cgi?id=1373

Replace BSD 2-Clause License with BSD+Patent License.  This change is
based on the following emails:

  https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html
  https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html

RFCs with detailed process for the license change:

  V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html
  V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html
  V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
2019-04-09 10:58:28 -07:00
Jian J Wang 2a93cccc24 UefiCpuPkg: restore strict page attributes via #DB in nonstop mode only
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1576

The root cause of this issue is that non-stop mode of Heap Guard and
NULL Detection set TF bit (single-step) in EFLAG unconditionally in
the common handler in CpuExceptionLib.

If PcdCpuSmmStaticPageTable is FALSE, the SMM will only create page
table for memory below 4G. If SMM tries to access memory beyond 4G,
a page fault exception will be triggered and the memory to access
will be added to page table so that SMM code can continue the access.

Because of above issue, the TF bit is set after the page fault is
handled and then fall into another DEBUG exception. Since non-stop
mode of Heap Guard and NULL Detection are not enabled, no special
DEBUG exception handler is registered. The default handler just
prints exception context and go into dead loop.

Actually EFLAGS can be changed in any standard exception handler.
There's no need to do single-step setup in assembly code. So the fix
is to move the logic to C code part of page fault exception handler
so that we can fully validate the configuration and prevent TF bit
from being set unexpectedly.

Fixes: dcc026217f
       16b918bbaf
Test:
 - Pass special test of accessing memory beyond 4G in SMM mode
 - Boot to OS with Qemu emulator platform (Fedora27, Ubuntu18.04,
   Windows7, Windows10)

Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
2019-03-01 11:17:17 +08:00
Jian J Wang 16b918bbaf UefiCpuPkg/CpuExceptionHandlerLib: Setup single step in #PF handler
Once the #PF handler has set the page to be 'present', there should
be a way to reset it to 'not-present'. 'TF' bit in EFLAGS can be used
for this purpose. 'TF' bit will be set in interrupted function context
so that it can be triggered once the cpu control returns back to the
instruction causing #PF and re-execute it.

This is an necessary step to implement non-stop mode for Heap Guard
and NULL Pointer Detection feature.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2018-08-30 07:22:29 +08:00
Liming Gao 2db0ccc2d7 UefiCpuPkg: Update CpuExceptionHandlerLib pass XCODE5 tool chain
https://bugzilla.tianocore.org/show_bug.cgi?id=849

In V2, use mov rax, strict qword 0 to replace the hard code db.

Use the dummy address as jmp destination, and add the logic to fix up
the address to the absolute address at boot time.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Liming Gao <liming.gao@intel.com>
Cc: Andrew Fish <afish@apple.com>
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>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2018-01-16 23:42:48 +08:00
Liming Gao fb501e33c3 UefiCpuPkg CpuExceptionHandlerLib:Convert X64/ExceptionHandlerAsm.asm to NASM
The BaseTools/Scripts/ConvertMasmToNasm.py script was used to convert
X64/ExceptionHandlerAsm.asm to X64/ExceptionHandlerAsm.nasm.
Then, manually update nasm to pass build.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
2016-06-28 09:52:10 +08:00