On macos I was running ./miniruby --mmtk -e 'puts "Hello world!"' and seeing a panic:
thread '<unnamed>' panicked at /src/util/raw_memory_freelist.rs:202:9:
Can't get more space with mmap()
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fatal runtime error: failed to initiate panic, error 5
Abort trap: 6
On macos, you can't combine PROT_EXEC with PROT_WRITE and PROT_READ in mmap, it will return a permission denied error. It's not clear from the Can't get more space with mmap() that's what was happening, but I could see it when inspecting the ret from mmap_fixed in dzmmap_noreplace.
Note: there are still failing tests for mmap on macos. The main change with this PR is that it no longer panics when runnning a simple hello world with Ruby on macos. Previously the build wasn't finishing and would throw the following error:
On macos I was running
./miniruby --mmtk -e 'puts "Hello world!"'and seeing a panic:On macos, you can't combine
PROT_EXECwithPROT_WRITEandPROT_READinmmap, it will return a permission denied error. It's not clear from theCan't get more space with mmap()that's what was happening, but I could see it when inspecting theretfrommmap_fixedindzmmap_noreplace.I found a thread on apple confirming that
PROT_EXECdoesn't make sense for macos in this context. https://forums.developer.apple.com/forums/thread/740017Note: there are still failing tests for
mmapon macos. The main change with this PR is that it no longer panics when runnning a simple hello world with Ruby on macos. Previously the build wasn't finishing and would throw the following error:Now the tests do finish, with 25 failures.