Merge branch 'master' into set-sockaddr-length-linux

10 files changed, 39 insertions, 23 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index daa8b6d9..c87abc4b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 - Added `mq_timedreceive` to `::nix::mqueue`.
   ([#1966])(https://github.com/nix-rust/nix/pull/1966)
 - Added `LocalPeerPid` to `nix::sys::socket::sockopt` for macOS. ([#1967](https://github.com/nix-rust/nix/pull/1967))
+- Added `TFD_TIMER_CANCEL_ON_SET` to `::nix::sys::time::TimerSetTimeFlags` on Linux and Android.
+  ([#2040](https://github.com/nix-rust/nix/pull/2040))
 
 ### Changed
 
diff --git a/Cargo.toml b/Cargo.toml
index 18b3a47d..ee3882ac 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,7 +32,7 @@ bitflags = "1.1"
 cfg-if = "1.0"
 pin-utils = { version = "0.1.0", optional = true }
 static_assertions = "1"
-memoffset = { version = "0.8", optional = true }
+memoffset = { version = "0.9", optional = true }
 
 [features]
 default = [
diff --git a/src/fcntl.rs b/src/fcntl.rs
index a9ef9ad1..d799ff37 100644
--- a/src/fcntl.rs
+++ b/src/fcntl.rs
@@ -701,7 +701,7 @@ pub fn vmsplice(
 }
 }
 
-#[cfg(any(target_os = "linux"))]
+#[cfg(target_os = "linux")]
 #[cfg(feature = "fs")]
 libc_bitflags!(
     /// Mode argument flags for fallocate determining operation performed on a given range.
@@ -741,7 +741,7 @@ feature! {
 ///
 /// Allows the caller to directly manipulate the allocated disk space for the
 /// file referred to by fd.
-#[cfg(any(target_os = "linux"))]
+#[cfg(target_os = "linux")]
 #[cfg(feature = "fs")]
 pub fn fallocate(
     fd: RawFd,
diff --git a/src/features.rs b/src/features.rs
index 39d17604..2f07a8fc 100644
--- a/src/features.rs
+++ b/src/features.rs
@@ -6,6 +6,7 @@ mod os {
     use crate::sys::utsname::uname;
     use crate::Result;
     use std::os::unix::ffi::OsStrExt;
+    use std::sync::atomic::{AtomicUsize, Ordering};
 
     // Features:
     // * atomic cloexec on socket: 2.6.27
@@ -72,15 +73,15 @@ mod os {
     }
 
     fn kernel_version() -> Result<usize> {
-        static mut KERNEL_VERS: usize = 0;
+        static KERNEL_VERS: AtomicUsize = AtomicUsize::new(0);
+        let mut kernel_vers = KERNEL_VERS.load(Ordering::Relaxed);
 
-        unsafe {
-            if KERNEL_VERS == 0 {
-                KERNEL_VERS = parse_kernel_version()?;
-            }
-
-            Ok(KERNEL_VERS)
+        if kernel_vers == 0 {
+            kernel_vers = parse_kernel_version()?;
+            KERNEL_VERS.store(kernel_vers, Ordering::Relaxed);
         }
+
+        Ok(kernel_vers)
     }
 
     /// Check if the OS supports atomic close-on-exec for sockets
diff --git a/src/sys/ptrace/linux.rs b/src/sys/ptrace/linux.rs
index 9687e05d..8c134cf7 100644
--- a/src/sys/ptrace/linux.rs
+++ b/src/sys/ptrace/linux.rs
@@ -269,7 +269,7 @@ unsafe fn ptrace_other(
     .map(|_| 0)
 }
 
-/// Set options, as with `ptrace(PTRACE_SETOPTIONS,...)`.
+/// Set options, as with `ptrace(PTRACE_SETOPTIONS, ...)`.
 pub fn setoptions(pid: Pid, options: Options) -> Result<()> {
     let res = unsafe {
         libc::ptrace(
@@ -282,17 +282,17 @@ pub fn setoptions(pid: Pid, options: Options) -> Result<()> {
     Errno::result(res).map(drop)
 }
 
-/// Gets a ptrace event as described by `ptrace(PTRACE_GETEVENTMSG,...)`
+/// Gets a ptrace event as described by `ptrace(PTRACE_GETEVENTMSG, ...)`
 pub fn getevent(pid: Pid) -> Result<c_long> {
     ptrace_get_data::<c_long>(Request::PTRACE_GETEVENTMSG, pid)
 }
 
-/// Get siginfo as with `ptrace(PTRACE_GETSIGINFO,...)`
+/// Get siginfo as with `ptrace(PTRACE_GETSIGINFO, ...)`
 pub fn getsiginfo(pid: Pid) -> Result<siginfo_t> {
     ptrace_get_data::<siginfo_t>(Request::PTRACE_GETSIGINFO, pid)
 }
 
-/// Set siginfo as with `ptrace(PTRACE_SETSIGINFO,...)`
+/// Set siginfo as with `ptrace(PTRACE_SETSIGINFO, ...)`
 pub fn setsiginfo(pid: Pid, sig: &siginfo_t) -> Result<()> {
     let ret = unsafe {
         Errno::clear();
@@ -517,12 +517,14 @@ pub fn sysemu_step<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
     }
 }
 
-/// Reads a word from a processes memory at the given address
+/// Reads a word from a processes memory at the given address, as with
+/// ptrace(PTRACE_PEEKDATA, ...)
 pub fn read(pid: Pid, addr: AddressType) -> Result<c_long> {
     ptrace_peek(Request::PTRACE_PEEKDATA, pid, addr, ptr::null_mut())
 }
 
-/// Writes a word into the processes memory at the given address
+/// Writes a word into the processes memory at the given address, as with
+/// ptrace(PTRACE_POKEDATA, ...)
 ///
 /// # Safety
 ///
@@ -536,13 +538,13 @@ pub unsafe fn write(
     ptrace_other(Request::PTRACE_POKEDATA, pid, addr, data).map(drop)
 }
 
-/// Reads a word from a user area at `offset`.
+/// Reads a word from a user area at `offset`, as with ptrace(PTRACE_PEEKUSER, ...).
 /// The user struct definition can be found in `/usr/include/sys/user.h`.
 pub fn read_user(pid: Pid, offset: AddressType) -> Result<c_long> {
     ptrace_peek(Request::PTRACE_PEEKUSER, pid, offset, ptr::null_mut())
 }
 
-/// Writes a word to a user area at `offset`.
+/// Writes a word to a user area at `offset`, as with ptrace(PTRACE_POKEUSER, ...).
 /// The user struct definition can be found in `/usr/include/sys/user.h`.
 ///
 /// # Safety
diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs
index ffab9741..c77bc961 100644
--- a/src/sys/socket/mod.rs
+++ b/src/sys/socket/mod.rs
@@ -236,7 +236,7 @@ impl SockProtocol {
     #[allow(non_upper_case_globals)]
     pub const CanBcm: SockProtocol = SockProtocol::NetlinkUserSock; // Matches libc::CAN_BCM
 }
-#[cfg(any(target_os = "linux"))]
+#[cfg(target_os = "linux")]
 libc_bitflags! {
     /// Configuration flags for `SO_TIMESTAMPING` interface
     ///
diff --git a/src/sys/socket/sockopt.rs b/src/sys/socket/sockopt.rs
index a18b5905..d5bcda4c 100644
--- a/src/sys/socket/sockopt.rs
+++ b/src/sys/socket/sockopt.rs
@@ -683,7 +683,7 @@ sockopt_impl!(
     libc::IP6T_SO_ORIGINAL_DST,
     libc::sockaddr_in6
 );
-#[cfg(any(target_os = "linux"))]
+#[cfg(target_os = "linux")]
 sockopt_impl!(
     /// Specifies exact type of timestamping information collected by the kernel
     /// [Further reading](https://www.kernel.org/doc/html/latest/networking/timestamping.html)
@@ -702,7 +702,7 @@ sockopt_impl!(
     libc::SO_TIMESTAMP,
     bool
 );
-#[cfg(all(target_os = "linux"))]
+#[cfg(target_os = "linux")]
 sockopt_impl!(
     /// Enable or disable the receiving of the `SO_TIMESTAMPNS` control message.
     ReceiveTimestampns,
diff --git a/src/sys/time.rs b/src/sys/time.rs
index a1894e4d..30ee5fd1 100644
--- a/src/sys/time.rs
+++ b/src/sys/time.rs
@@ -93,6 +93,7 @@ pub(crate) mod timer {
         /// Flags that are used for arming the timer.
         pub struct TimerSetTimeFlags: libc::c_int {
             const TFD_TIMER_ABSTIME = libc::TFD_TIMER_ABSTIME;
+            const TFD_TIMER_CANCEL_ON_SET = libc::TFD_TIMER_CANCEL_ON_SET;
         }
     }
     #[cfg(any(
diff --git a/src/sys/timerfd.rs b/src/sys/timerfd.rs
index 90a05a8c..c4337c9d 100644
--- a/src/sys/timerfd.rs
+++ b/src/sys/timerfd.rs
@@ -135,6 +135,13 @@ impl TimerFd {
     /// Then the one shot TimeSpec and the delay TimeSpec of the delayed
     /// interval are going to be interpreted as absolute.
     ///
+    /// # Cancel on a clock change
+    ///
+    /// If you set a `TFD_TIMER_CANCEL_ON_SET` alongside `TFD_TIMER_ABSTIME`
+    /// and the clock for this timer is `CLOCK_REALTIME` or `CLOCK_REALTIME_ALARM`,
+    /// then this timer is marked as cancelable if the real-time clock undergoes
+    /// a discontinuous change.
+    ///
     /// # Disabling alarms
     ///
     /// Note: Only one alarm can be set for any given timer. Setting a new alarm
@@ -202,6 +209,9 @@ impl TimerFd {
     /// Note: If the alarm is unset, then you will wait forever.
     pub fn wait(&self) -> Result<()> {
         while let Err(e) = read(self.fd.as_fd().as_raw_fd(), &mut [0u8; 8]) {
+            if e == Errno::ECANCELED {
+                break;
+            }
             if e != Errno::EINTR {
                 return Err(e);
             }
diff --git a/test/test_fcntl.rs b/test/test_fcntl.rs
index 8f50f16b..de502d1a 100644
--- a/test/test_fcntl.rs
+++ b/test/test_fcntl.rs
@@ -238,7 +238,7 @@ mod linux_android {
     use nix::unistd::{close, pipe, read, write};
 
     use tempfile::tempfile;
-    #[cfg(any(target_os = "linux"))]
+    #[cfg(target_os = "linux")]
     use tempfile::NamedTempFile;
 
     use crate::*;
@@ -355,7 +355,7 @@ mod linux_android {
         close(wr).unwrap();
     }
 
-    #[cfg(any(target_os = "linux"))]
+    #[cfg(target_os = "linux")]
     #[test]
     fn test_fallocate() {
         let tmp = NamedTempFile::new().unwrap();