Check that pthread mutex initialization succeeded

If pthread mutex initialization fails, the failure will go unnoticed unless
debug assertions are enabled. Any subsequent use of mutex will also silently
fail, since return values from lock & unlock operations are similarly checked
only through debug assertions.

In some implementations the mutex initialization requires a memory
allocation and so it does fail in practice.

Check that initialization succeeds to ensure that mutex guarantees
mutual exclusion.

1 files changed, 1 insertions, 5 deletions

diff --git a/library/std/src/sys/unix/process/process_unix.rs b/library/std/src/sys/unix/process/process_unix.rs
index b05319c89e8..a590c744356 100644
--- a/library/std/src/sys/unix/process/process_unix.rs
+++ b/library/std/src/sys/unix/process/process_unix.rs
@@ -281,7 +281,7 @@ impl Command {
         envp: Option<&CStringArray>,
     ) -> io::Result<Option<Process>> {
         use crate::mem::MaybeUninit;
-        use crate::sys;
+        use crate::sys::{self, cvt_nz};
 
         if self.get_gid().is_some()
             || self.get_uid().is_some()
@@ -343,10 +343,6 @@ impl Command {
             }
         }
 
-        fn cvt_nz(error: libc::c_int) -> io::Result<()> {
-            if error == 0 { Ok(()) } else { Err(io::Error::from_raw_os_error(error)) }
-        }
-
         unsafe {
             let mut attrs = MaybeUninit::uninit();
             cvt_nz(libc::posix_spawnattr_init(attrs.as_mut_ptr()))?;