Most changes are around user and group management, which are exposed in
the Android NDK differently than other Unices.
We require version 30 for memfd_create, version 28 for posix_spawn, and
so on. It's possible a shim for memfd_create could be used, but since
Google is mandating new apps use API level 30 as of Nov 2022, this seems
suitable.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
This commit moves the length calculations out to be directly on the
StringView users. This is an important step towards the goal of removing
StringView(char const*), as it moves the responsibility of calculating
the size of the string to the user of the StringView (which will prevent
naive uses causing OOB access).
The extra argument to fcntl is a pointer in the case of F_GETLK/F_SETLK
and we were pulling out a u32, leading to pointer truncation on x86_64.
Among other things, this fixes Assistant on x86_64 :^)
This is a single function, which behaves like the various LibC exec()
functions depending on the passed parameters. No direct equivalent is
made for execl() - you have to wrap your arguments in a Span of some
kind.
On Serenity, this calls the syscall directly, whereas Lagom forwards to
the appropriate LibC function.
In a few places we intentionally drop privileges to reduce the potential
security surface area of networked program, with the pattern of:
```
if (setgid(getgid()) || setuid(getuid()) {
return 1;
}
```
We can make this a bit nicer to use by creating a wrapper.
I also added a common interface with StringView compatible parameters:
int serenity_setenv(const char*, ssize_t, const char*, ssize_t, int)
This function is called by both C and C++ API for setenv().
This wrapper is particularly helpful as we use a combination of similar
syscalls on Linux to simulate the behavior of the Serenity-exclusive
anon_create syscall. Users therefore won't have to worry about the
platform anymore :^)
This function is an extended version of `chmod(2)` that lets one control
whether to dereference symlinks, and specify a file descriptor to a
directory that will be used as the base for relative paths.
We should not expect LibC functions to clear `errno` on success,
so if we want to use it for error checking after a call, we need
to clear it before the call.
