Laszlo Ersek 41bfaffd13 MdePkg/BaseSafeIntLib: fix undefined behavior in SafeInt64Add()
The addition in the assignment

  SignedResult = Augend + Addend;

is performed with unchecked INT64 operands. According to ISO C, if the
mathematical result of signed integer addition cannot be represented in
the result type, the behavior is undefined. (Refer to ISO C99 6.5p5.
6.2.5p9 only exempts unsigned integers, and 6.3.1.3p3 does not apply
because it treats the conversion of integers that have been successfully
evaluated first.)

Replace the after-the-fact result checking with checks on the operands,
and only perform the addition if it is safe.

Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Michael D Kinney <michael.d.kinney@intel.com>
2018-02-21 11:57:33 +01:00
2018-02-10 19:55:13 +08:00
2014-10-14 16:08:15 +00:00

EDK II Project

A modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications from www.uefi.org.

Contributions to the EDK II open source project are covered by the TianoCore Contribution Agreement 1.1

The majority of the content in the EDK II open source project uses a BSD 2-Clause License. The EDK II open source project contains the following components that are covered by additional licenses:

The EDK II Project is composed of packages. The maintainers for each package are listed in Maintainers.txt.

Resources

Description
Acidanthera UEFI Development Kit based on EDK II edk2-stable202405
Readme 319 MiB
Languages
C 76.4%
Assembly 10.5%
Python 9.3%
Rich Text Format 1.5%
C++ 0.8%
Other 1.1%