Considering the following integer multiplication:
u64 = u16 * u16
What on earth, one might wonder, is the problem with this? Well, due to
C's unfortunately abstruse integer semantics, both u16's are implicitly
converted to int before the multiplication, which cannot hold
all possible values of a u16 * u16. Even worse, after overflow the
intermediate result will be a negative number, which during the
conversion to a u64 will be sign-extended to a huge integer. Not good.
The solution is to manually cast one of the u16 to a u32 or u64, which
are large enough to not have any overflow and will prevent the implicit
conversion. The type of the u64 is preferred, though a u32 is used
instead of size_t, since that can change depending on the platform.
Change-Id: I5391221d46d620d0e5bd629e2f9680be7a53342e
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Found-by: Coverity CID 12297{03,04,05,06,07,08,09,10}
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33986
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
abuild - coreboot autobuild script builds coreboot images for all
available targets. bash
acpi - Walk through all ACPI tables with their addresses. bash
amdfwtool - Create AMD Firmware combination C
amdtools - A set of tools to compare extended) K8 memory
settings. Perl
archive - Concatenate files and create an archive C
mksunxiboot - A simple tool to generate bootable image for sunxi
platform. C
autoport - Automated porting coreboot to Sandy Bridge/Ivy Bridge
platforms Go
bimgtool - A simple tool which generates and verifies boot images
in the BIMG format, used in systems designed by Imagination
Technologies, for example the Pistachio SoC. C
bincfg - Compiler/Decompiler for data blobs with specs LexYacc
board_status - Tools to collect logs and upload them to the board
status repository BashGo
bucts - A tool to manipulate the BUC.TS bit on Intel targets. C
cavium - Devicetree_convert Tool to convert a DTB to a static C
file Python
cbfstool
cbfstool - For manipulating CBFS file C
fmaptool - Converts plaintext fmd files into fmap blobs C
rmodtool - Creates rmodules C
ifwitool - For manipulating IFWI C
cbmem - Cbmem console log reader C
checklist - Board implementation checklist generator Make
chromeos - These scripts can be used to extract System Agent
reference code and other blobs (e.g. mrc.bin, refcode, VGA option roms)
from a Chrome OS recovery image. C
crossgcc - A cross toolchain builder for -elf toolchains (ie. no
libc support)
docker - Dockerfiles for coreboot-sdk, coreboot-jenkins-node,
coreboot.org-status and docs.coreboot.org
dtd_parser - DTD structure parser Python2
ectool - Dumps the RAM of a laptop's Embedded/Environmental
Controller (EC). C
exynos - Computes and fills Exynos ROM checksum (for BL1 or BL2).
Python2
find_usbdebug - Help find USB debug ports
futility - Firmware utility for signing ChromeOS images Make
fuzz-tests - Create test cases that crash the jpeg code. C
genbuild_h - Generate build system definitions Shell
ifdtool - Extract and dump Intel Firmware Descriptor information
C
intelmetool - Dump interesting things about Management Engine
even if hidden C
inteltool - Provides information about the Intel CPU/chipset
hardware configuration (register contents, MSRs, etc). C
intelvbttool - Parse VBT from VGA BIOS C
ipqheader
createxbl.py - Concatentates XBL segments into one ELF
image Python
ipqheader.py - Returns a packed MBN header image with the
specified base and size Python
mbncat.py - Generate ipq8064 uber SBL Python
mbn_tools.py - Contains all MBN Utilities for image
generation Python
k8resdump - This program will dump the IO/memory/PCI resources
from the K8 memory controller C
kbc1126 - Tools used to dump the two blobs from the factory
firmware of many HP laptops with 8051-based SMSC KBC1098/KBC1126
embedded controller and insert them to the firmware image. C
kconfig - Build system Make
lint - Source linter and linting rules Shell
marvell - Add U-Boot boot loader for Marvell ARMADA38X C
me_cleaner - Tool for
partial deblobbing of Intel ME/TXE firmware images Python
nvramtool - Reads and writes coreboot parameters and displaying
information from the coreboot table in CMOS/NVRAM. C
pmh7tool - Dumps, reads and writes PMH7 registers on Lenovo
ThinkPads. PMH7 is used for switching on and off the power of some
devices on the board such as dGPU. C
post - Userspace utility that can be used to test POST cards. C
qualcomm - CMM script to debug Qualcomm coreboot environments.
CMM
release - Generate coreboot release Bash
riscv
make-spike-elf.sh - Converts a flat file into an ELF, that
can be passed to SPIKE, the RISC-V reference emulator.Bash
sifive-gpt.py - Wraps the bootblock in a GPT partition for
SiFive's bootrom. Python3
romcc - Compile a C source file generating a binary that does not
implicitly use RAM. C
sconfig - coreboot device tree compiler LexYacc
scripts
config - Manipulate options in a .config file from the
command line Bash
cross-repo-cherrypick - Pull in patches from another tree
from a gerrit repository. Shell
dts-to-fmd.sh -Converts a depthcharge fmap.dts into an
fmaptool compatible .fmd format Bash
find-unused-kconfig-symbols.sh - Points out Kconfig
variables that may be unused. There are some false positives, but it
serves as a starting point Shell
gerrit-rebase - Applies all commits that from-branch has
over to-branch, based on a common ancestor and gerrit meta-data Bash
get_maintainer.pl - Print selected MAINTAINERS information
for the files modified in a patch or for a file Perl
maintainers.go - Build subsystem Maintainers Go
no-fsf-addresses.sh - Removes various FSF addresses from
license headers Shell
parse-maintainers.pl - Script to alphabetize MAINTAINERS
file Perl
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