Pervasive misuse of "ETH_MAC *" (a pointer to an ETH_MAC, aka a 6
element unsigned char array) when a simple "ETH_MAC" is correct. The
best example of this was eth_mac_fmt() in sim_ether.c with the following
prototype:
t_stat eth_mac_fmt (ETH_MAC* const mac, char* strmac)
The first parameter is a pointer to an array of 6 unsigned characters,
whereas it really just wants to be a pointer to the first element of the
array:
t_stat eth_mac_scan (const ETH_MAC mac, char* strmac)
The "ETH_MAC *" indirection error also results in subtle memcpy() and
memcmp() issues, e.g.:
void network_func(DEVICE *dev, ETH_MAC *mac)
{
ETH_MAC other_mac;
/* ...code... */
/* memcpy() bug: */
memcpy(other_mac, mac, sizeof(ETH_MAC));
/* or worse: */
memcpy(mac, other_mac, sizeof(ETH_MAC));
}
eth_copy_mac() and eth_mac_cmp() replace calls to memcpy() and memcmp()
that copy or compare Ethernet MAC addresses. These are type-enforcing
functions, i.e., the parameters are ETH_MAC-s, to avoid the subtle
memcpy() and memcmp() bugs.
This fix solves at least one Heisenbug in _eth_close() while free()-ing
write request buffers (and possibly other Heisenbugs.)
Open SIMH machine simulator
This is the codebase of SIMH, a framework and collection of computer system simulators.
SIMH was created by Bob Supnik, originally at Digital Equipment Corporation, and extended by contributions of many other people. It is now an open source project, licensed under an MIT open source license (see LICENSE.txt for the specific wording). The project gatekeepers are the members of the SIMH Steering Group. We welcome and encourage contributions from all. Contributions will be covered by the project license.
The Open SIMH code base was taken from a code base maintained by Mark Pizzolato as of 12 May 2022. From that point onward there is no connection between that source and the Open SIMH code base. A detailed listing of features as of that point may be found in SIMH-V4-status.
PLEASE NOTE
Do not contribute material taken from github.com/simh/simh unless you are the author of the material in question.