Commit Graph

7 Commits

Author SHA1 Message Date
Zhiguang Liu 8a5782d704 UefiCpuPkg: Fix nasm warning "signed byte value exceeds"
Currently, "push byte %[Vector]" causes nasm warning when Vector is larger
than 0x7F. This is because push accepts a signed value, and byte means
signed int8. Maximum signed int8 is 0x7F.
When Vector is larger the 0x7F, for example, when Vector is 255, byte 255
turns to -1, and causes the warning "signed byte value exceeds".
To avoid such warning, use dword instead of byte, this will increase 3 bytes
for each IdtVector.
For IA32, the size of IdtVector will increase from 10 bytes to 13 bytes.
For X64, the size of IdtVector will increase from 15 bytes to 18 bytes.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Debkumar De <debkumar.de@intel.com>
Cc: Harry Han <harry.han@intel.com>
Cc: Catharine West <catharine.west@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
2022-07-25 02:18:26 +00:00
Ray Ni 21a9b605b8 CpuException: Avoid allocating code pages for DXE instance
Today the DXE instance allocates code page and then copies the IDT
vectors to the allocated code page. Then it fixes up the vector number
in the IDT vector.

But if we update the NASM file to generate 256 IDT vectors, there is
no need to do the copy and fix-up.

A side effect is 4096 bytes (HOOKAFTER_STUB_SIZE * 256) is used for
256 IDT vectors while 32 IDT vectors only require 512 bytes without
this change, in following library instances:
1. 32bit SecPeiCpuExceptionHandlerLib and PeiCpuExceptionHandlerLib
2. 64bit PeiCpuExceptionHandlerLib

But considering the code logic simplification, 3.5K extra space is
not a big deal.
If 3.5K is too much, we can enhance the code further to generate 32
vectors for above mentioned library instances.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Acked-by: Eric Dong <eric.dong@intel.com>
2022-06-10 07:54:48 +00:00
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
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 ab7efb664c UefiCpuPkg CpuExceptionHandlerLib:Convert Ia32/ExceptionHandlerAsm.asm to NASM
The BaseTools/Scripts/ConvertMasmToNasm.py script was used to convert
Ia32/ExceptionHandlerAsm.asm to Ia32/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 09:52:09 +08:00