Init no longer changes the default scheme to initfs at any point in
time. And for sandboxing you would be switching scheme namespace, not
default scheme.
It should be possible to mix and match relibc version from before and
after this change without breaking exec, though I haven't tested it.
`pthread_atfork` should be exported in pthread.h according to the
standard. We only exported our function in unistd.h. `glibc` exports it
in both pthread.h and unistd.h whereas musl only exports it in pthread.h
(which is standards compliant).
I exported it in both headers. Cbindgen doesn't seem to reexport `pub
use` so I declared the function twice. We might have to reexamine our
`pub use` to check what's exported and what isn't.
The implementation for confstr is straightforward. Most of the constants
return 1 on both musl and glibc. The only constant that doesn't is
required for Fish.
I also switched an #[unsafe(no_mangle)] from my last patch back
to a #[no_mangle] because we need to bump cbindgen. #[unsafe(no_mangle)]
is required for Rust 2024.
I copied the constants and definitions from musl which we can presume is
correct. Relibc is missing some features which affects our sysconf as
well, such as constants in limits.h or a working resources.h.
`_Exit`, `exit`, and related functions should return `!` because they
don't return. This also signals to cbindgen that it should emit
`[[noreturn]]` for those functions.
As we know, vectors amortize the cost of adding new elements by reserving
space for multiple elements when full. This is useful but may lead to
allocating more memory than necessary.
`relibc` generally avoids over allocations by reserving the exact amount
of space when possible. I fixed a few areas that still over allocated or
reallocated unnecessarily by leveraging iterators that are more likely
to know sizes.
auronandace