rutabaga_gfx: Uprev nix to 0.27.1

The new version of nix uses OwnedFd in various places, which allows us
to have less unsafe code.

TEST=CQ
BUG=b:293289578

Change-Id: I61aa80c4105eaf1182c5c325109b5aba11cf60de
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/5072293
Auto-Submit: Andrew Walbran <qwandor@google.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Frederick Mayle <fmayle@google.com>
Commit-Queue: Frederick Mayle <fmayle@google.com>

Cargo.lock

@@ -1654,18 +1654,18 @@ dependencies = [
 
 [[package]]
 name = "memoffset"
-version = "0.7.1"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5de893c32cde5f383baa4c04c5d6dbdd735cfd4a794b0debdb2bb1b421da5ff4"
+checksum = "d61c719bcfbcf5d62b3a09efa6088de8c54bc0bfcd3ea7ae39fcc186108b8de1"
 dependencies = [
  "autocfg",
 ]
 
 [[package]]
 name = "memoffset"
-version = "0.8.0"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d61c719bcfbcf5d62b3a09efa6088de8c54bc0bfcd3ea7ae39fcc186108b8de1"
+checksum = "5a634b1c61a95585bd15607c6ab0c4e5b226e695ff2800ba0cdccddf208c406c"
 dependencies = [
  "autocfg",
 ]
@@ -1790,8 +1790,6 @@ dependencies = [
  "bitflags 1.3.2",
  "cfg-if",
  "libc",
- "memoffset 0.7.1",
- "pin-utils",
  "static_assertions",
 ]
 
@@ -1804,6 +1802,7 @@ dependencies = [
  "bitflags 2.3.2",
  "cfg-if",
  "libc",
+ "memoffset 0.9.0",
 ]
 
 [[package]]
@@ -2310,7 +2309,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "log",
- "nix 0.26.2",
+ "nix 0.27.1",
  "pkg-config",
  "remain",
  "thiserror",

rutabaga_gfx/Cargo.toml

@@ -27,7 +27,7 @@ zerocopy = { version = "0.7", features = ["derive"] }
 log = "0.4"
 
 [target.'cfg(any(target_os = "android", target_os = "linux"))'.dependencies]
-nix = "0.26.1"
+nix = { version = "0.27.1", features = ["event", "feature", "fs", "mman", "socket", "uio"] }
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.3"

rutabaga_gfx/src/cross_domain/sys/linux.rs

@@ -8,7 +8,6 @@ use std::io::IoSliceMut;
 use std::io::Seek;
 use std::io::SeekFrom;
 use std::os::unix::io::AsRawFd;
-use std::os::unix::io::FromRawFd;
 use std::os::unix::prelude::AsFd;
 
 use libc::O_ACCMODE;
@@ -160,8 +159,8 @@ impl CrossDomainContext {
         )?;
 
         let unix_addr = UnixAddr::new(base_channel)?;
-        connect(socket_fd, &unix_addr)?;
-        let stream = unsafe { File::from_raw_fd(socket_fd) };
+        connect(socket_fd.as_raw_fd(), &unix_addr)?;
+        let stream = socket_fd.into();
         Ok(Some(stream))
     }
 
@@ -277,7 +276,7 @@ pub fn write_volatile(file: &File, opaque_data: &[u8]) -> RutabagaResult<()> {
 }
 
 pub fn channel() -> RutabagaResult<(Sender, Receiver)> {
-    let sender = unsafe { File::from_raw_fd(eventfd(0, EfdFlags::empty())?) };
+    let sender: File = eventfd(0, EfdFlags::empty())?.into();
     let receiver = sender.try_clone()?;
     Ok((sender, receiver))
 }

rutabaga_gfx/src/rutabaga_os/sys/linux/descriptor.rs

@@ -4,6 +4,8 @@
 
 use std::convert::TryFrom;
 use std::fs::File;
+use std::os::fd::AsFd;
+use std::os::fd::BorrowedFd;
 use std::os::unix::io::AsRawFd;
 use std::os::unix::io::FromRawFd;
 use std::os::unix::io::IntoRawFd;
@@ -85,6 +87,14 @@ impl AsRawFd for Descriptor {
     }
 }
 
+impl AsFd for SafeDescriptor {
+    fn as_fd(&self) -> BorrowedFd {
+        // SAFETY: the `BorrowedFd` we return lives no longer than this `SafeDescriptor`, so the
+        // descriptor will remain open.
+        unsafe { BorrowedFd::borrow_raw(self.descriptor) }
+    }
+}
+
 macro_rules! AsRawDescriptor {
     ($name:ident) => {
         impl AsRawDescriptor for $name {

rutabaga_gfx/src/rutabaga_os/sys/linux/memory_mapping.rs

@@ -10,7 +10,6 @@ use nix::sys::mman::munmap;
 use nix::sys::mman::MapFlags;
 use nix::sys::mman::ProtFlags;
 
-use crate::rutabaga_os::descriptor::AsRawDescriptor;
 use crate::rutabaga_os::descriptor::SafeDescriptor;
 use crate::rutabaga_utils::RutabagaError;
 use crate::rutabaga_utils::RutabagaResult;
@@ -59,7 +58,7 @@ impl MemoryMapping {
                     non_zero_size,
                     prot,
                     MapFlags::MAP_SHARED,
-                    descriptor.as_raw_descriptor(),
+                    Some(descriptor),
                     0,
                 )?
             };

rutabaga_gfx/src/rutabaga_os/sys/linux/shm.rs

@@ -4,8 +4,6 @@
 
 use std::convert::TryInto;
 use std::ffi::CStr;
-use std::os::unix::io::AsRawFd;
-use std::os::unix::io::FromRawFd;
 use std::os::unix::io::OwnedFd;
 
 use libc::off_t;
@@ -34,15 +32,13 @@ impl SharedMemory {
     ///
     /// The file descriptor is opened with the close on exec flag and allows memfd sealing.
     pub fn new(debug_name: &CStr, size: u64) -> RutabagaResult<SharedMemory> {
-        // Nix will transition to owned fd in future releases, do it locally here.
-        let raw_fd = memfd_create(
+        let fd = memfd_create(
             debug_name,
             MemFdCreateFlag::MFD_CLOEXEC | MemFdCreateFlag::MFD_ALLOW_SEALING,
         )?;
-        let fd = unsafe { OwnedFd::from_raw_fd(raw_fd) };
 
         let size_off_t: off_t = size.try_into()?;
-        ftruncate(fd.as_raw_fd(), size_off_t)?;
+        ftruncate(&fd, size_off_t)?;
 
         Ok(SharedMemory { fd, size })
     }