mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Avoid fork/exec spawning on tvOS/watchOS, as those functions are marked as prohibited

Browse Source
This commit is contained in:
Thom Chiovoloni 2023-06-04 09:46:18 -07:00
parent b80e0b7f53
commit 49da0acb71
No known key found for this signature in database
1 changed files with 48 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
library/std/src/sys/unix/process/process_unix.rs
View File

@ -15,6 +15,8 @@ use crate::sys::weak::raw_syscall;
#[cfg(any(
target_os = "macos",
target_os = "watchos",
target_os = "tvos",
target_os = "freebsd",
all(target_os = "linux", target_env = "gnu"),
all(target_os = "linux", target_env = "musl"),
@ -28,7 +30,12 @@ use libc::RTP_ID as pid_t;
#[cfg(not(target_os = "vxworks"))]
use libc::{c_int, pid_t};
#[cfg(not(any(target_os = "vxworks", target_os = "l4re")))]
#[cfg(not(any(
target_os = "vxworks",
target_os = "l4re",
target_os = "tvos",
target_os = "watchos",
)))]
use libc::{gid_t, uid_t};
cfg_if::cfg_if! {
@ -84,7 +91,6 @@ impl Command {
if let Some(ret) = self.posix_spawn(&theirs, envp.as_ref())? {
return Ok((ret, ours));
}
let (input, output) = sys::pipe::anon_pipe()?;
// Whatever happens after the fork is almost for sure going to touch or
@ -166,9 +172,32 @@ impl Command {
crate::sys_common::process::wait_with_output(proc, pipes)
}
// WatchOS and TVOS can theoretically spawn processes using `posix_spawn*`
// (although it just fails with a runtime error AFAICT, so we don't yet
// support it in `std`), but forbid use of `fork`/`exec*`. It's unclear the
// extent to which these is restricted, but the headers say
// `__WATCHOS_PROHIBITED __TVOS_PROHIBITED`, so we go out of our way to
// avoid containing any calls to them at all, to avoid linking against their
// symbols on those targets.
#[cfg(any(target_os = "tvos", target_os = "watchos"))]
const ERR_APPLE_TV_WATCH_NO_FORK_EXEC: Error = io::const_io_error!(
ErrorKind::Unsupported,
"`fork`+`exec`-based process spawning is not supported on this target",
);
#[cfg(any(target_os = "tvos", target_os = "watchos"))]
unsafe fn do_fork(&mut self) -> Result<(pid_t, pid_t), io::Error> {
return Err(Self::ERR_APPLE_TV_WATCH_NO_FORK_EXEC);
}
// Attempts to fork the process. If successful, returns Ok((0, -1))
// in the child, and Ok((child_pid, -1)) in the parent.
#[cfg(not(any(target_os = "linux", all(target_os = "nto", target_env = "nto71"))))]
#[cfg(not(any(
target_os = "linux",
target_os = "watchos",
target_os = "tvos",
all(target_os = "nto", target_env = "nto71"),
)))]
unsafe fn do_fork(&mut self) -> Result<(pid_t, pid_t), io::Error> {
cvt(libc::fork()).map(|res| (res, -1))
}
@ -339,6 +368,7 @@ impl Command {
// allocation). Instead we just close it manually. This will never
// have the drop glue anyway because this code never returns (the
// child will either exec() or invoke libc::exit)
#[cfg(not(any(target_os = "tvos", target_os = "watchos")))]
unsafe fn do_exec(
&mut self,
stdio: ChildPipes,
@ -445,8 +475,19 @@ impl Command {
Err(io::Error::last_os_error())
}
#[cfg(any(target_os = "tvos", target_os = "watchos"))]
unsafe fn do_exec(
&mut self,
_stdio: ChildPipes,
_maybe_envp: Option<&CStringArray>,
) -> Result<!, io::Error> {
return Err(Self::ERR_APPLE_TV_WATCH_NO_FORK_EXEC);
}
#[cfg(not(any(
target_os = "macos",
target_os = "tvos",
target_os = "watchos",
target_os = "freebsd",
all(target_os = "linux", target_env = "gnu"),
all(target_os = "linux", target_env = "musl"),
@ -464,6 +505,9 @@ impl Command {
// directly.
#[cfg(any(
target_os = "macos",
// FIXME: `target_os = "ios"`?
target_os = "tvos",
target_os = "watchos",
target_os = "freebsd",
all(target_os = "linux", target_env = "gnu"),
all(target_os = "linux", target_env = "musl"),
@ -550,7 +594,7 @@ impl Command {
}
let addchdir = match self.get_cwd() {
Some(cwd) => {
if cfg!(target_os = "macos") {
if cfg!(any(target_os = "macos", target_os = "tvos", target_os = "watchos")) {
// There is a bug in macOS where a relative executable
// path like "../myprogram" will cause `posix_spawn` to
// successfully launch the program, but erroneously return