On Friday, 23 September 2022 17:29:06 CEST Paul Boddie wrote:
I have been working through reimplementing the mechanisms involved with launching programs in L4Re, managing to initiate programs apparently successfully under QEMU emulating amd64 and x86, but I have been less successful getting them to work under QEMU emulating a MIPS system (MIPS Malta).
[An exploration of program threading initialisation.]
Does anyone have any familiarity with how this actually works and might be able to indicate what I am doing wrong?
Well, this was a mistake that I had made, naturally. Ignoring various shortcuts I had made when implementing my pagers and region mappers, I had also neglected to consider the potential for my region mappers to be handing out access to memory regions located in the same part of memory.
So, my region mapper was obtaining memory to initialise its threads, and the program being launched was also requesting memory and being told about a region in the same place, and you can imagine what happened next. I am still not entirely sure how two programs can go through their pthreads initialisation in the same address space, however.
Paul