Drop compatibility workaround and always use the generated taskstats def (#13)

Author: kawamuray

Diff for: src/lib.rs

@@ -10,7 +10,7 @@ mod model;
 pub(crate) mod netlink;
 pub use model::*;
 
-pub use c_headers::taskstats as __bindgen_taskstats;
+pub use c_headers::taskstats;
 use c_headers::{
     __u16, __u32, __u64, __u8, TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK, TASKSTATS_CMD_ATTR_PID,
     TASKSTATS_CMD_ATTR_REGISTER_CPUMASK, TASKSTATS_CMD_ATTR_TGID, TASKSTATS_CMD_GET,
@@ -279,69 +279,6 @@ impl<T> AsBuf<T> for T {
     }
 }
 
-/// This is custom copy of the generated `struct taskstats` from linux version 3.10.0 and in this crate
-/// this type is used to read binary data transferred from linux kernel.
-/// The reason of doing this despite the `bindgen` generates rust bindings including `struct taskstats`
-/// is due to potential corruption of on-memory struct layout likely caused by old clang version.
-/// ref: https://github.com/rust-lang/rust-bindgen/issues/867
-/// Specifically, when `bindgen` generates `struct taskstats` with older clang version, the resulting
-/// struct defined in generated rust source code contains size padding as the last member of the struct
-/// causing offset of members after `ac_uid` to shift 4-byte or more and the result data becomes unreliable.
-/// The `bindgen` generated definition works well in environment that uses newer clang versions, but I
-/// decided to use copied definition of this struct for the time being by following considerations:
-/// * The struct definition rarely evolves.
-/// * Returning corrupted data silently is critical and much worse than not providing from the beginning.
-/// * If user of this crate still needs to access the exactly original definition generated by `bindgen`,
-///   it might still be possible by casting type to `__bindgen_taskstats` exported by this crate.
-#[repr(C)]
-#[derive(Debug, Copy, Clone)]
-pub struct taskstats {
-    pub version: __u16,
-    pub ac_exitcode: __u32,
-    pub ac_flag: __u8,
-    pub ac_nice: __u8,
-    pub cpu_count: __u64,
-    pub cpu_delay_total: __u64,
-    pub blkio_count: __u64,
-    pub blkio_delay_total: __u64,
-    pub swapin_count: __u64,
-    pub swapin_delay_total: __u64,
-    pub cpu_run_real_total: __u64,
-    pub cpu_run_virtual_total: __u64,
-    pub ac_comm: [::std::os::raw::c_char; 32usize],
-    pub ac_sched: __u8,
-    pub ac_pad: [__u8; 3usize],
-    pub __unused_padding: u32,
-    pub ac_uid: __u32,
-    pub ac_gid: __u32,
-    pub ac_pid: __u32,
-    pub ac_ppid: __u32,
-    pub ac_btime: __u32,
-    pub ac_etime: __u64,
-    pub ac_utime: __u64,
-    pub ac_stime: __u64,
-    pub ac_minflt: __u64,
-    pub ac_majflt: __u64,
-    pub coremem: __u64,
-    pub virtmem: __u64,
-    pub hiwater_rss: __u64,
-    pub hiwater_vm: __u64,
-    pub read_char: __u64,
-    pub write_char: __u64,
-    pub read_syscalls: __u64,
-    pub write_syscalls: __u64,
-    pub read_bytes: __u64,
-    pub write_bytes: __u64,
-    pub cancelled_write_bytes: __u64,
-    pub nvcsw: __u64,
-    pub nivcsw: __u64,
-    pub ac_utimescaled: __u64,
-    pub ac_stimescaled: __u64,
-    pub cpu_scaled_run_real_total: __u64,
-    pub freepages_count: __u64,
-    pub freepages_delay_total: __u64,
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -353,8 +290,8 @@ mod tests {
         let ts = client.pid_stats(std::process::id()).unwrap();
 
         // Just asserts some fields which do likely have positive values
-        assert!(ts.cpu.utime_total.as_nanos() > 0);
-        assert!(ts.memory.rss_total > 0);
+        assert!(ts.delays.cpu.delay_total.as_nanos() > 0);
+        assert!(ts.cpu.virtual_time_total.as_nanos() > 0);
     }
 
     #[cfg(test_priv)]
@@ -364,142 +301,7 @@ mod tests {
         let ts = client.tgid_stats(std::process::id()).unwrap();
 
         // Just asserts some fields which do likely have positive values
-        assert!(ts.cpu.utime_total.as_nanos() > 0);
-        assert!(ts.memory.rss_total > 0);
-    }
-
-    #[test]
-    fn test_struct_taskstats_alignment() {
-        // Automatically generated by tools/gen_layout_test.sh
-        assert_eq!(328, std::mem::size_of::<taskstats>());
-        assert_eq!(0, unsafe {
-            &(*(std::ptr::null::<taskstats>())).version as *const _ as usize
-        });
-        assert_eq!(4, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_exitcode as *const _ as usize
-        });
-        assert_eq!(8, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_flag as *const _ as usize
-        });
-        assert_eq!(9, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_nice as *const _ as usize
-        });
-        assert_eq!(16, unsafe {
-            &(*(std::ptr::null::<taskstats>())).cpu_count as *const _ as usize
-        });
-        assert_eq!(24, unsafe {
-            &(*(std::ptr::null::<taskstats>())).cpu_delay_total as *const _ as usize
-        });
-        assert_eq!(32, unsafe {
-            &(*(std::ptr::null::<taskstats>())).blkio_count as *const _ as usize
-        });
-        assert_eq!(40, unsafe {
-            &(*(std::ptr::null::<taskstats>())).blkio_delay_total as *const _ as usize
-        });
-        assert_eq!(48, unsafe {
-            &(*(std::ptr::null::<taskstats>())).swapin_count as *const _ as usize
-        });
-        assert_eq!(56, unsafe {
-            &(*(std::ptr::null::<taskstats>())).swapin_delay_total as *const _ as usize
-        });
-        assert_eq!(64, unsafe {
-            &(*(std::ptr::null::<taskstats>())).cpu_run_real_total as *const _ as usize
-        });
-        assert_eq!(72, unsafe {
-            &(*(std::ptr::null::<taskstats>())).cpu_run_virtual_total as *const _ as usize
-        });
-        assert_eq!(80, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_comm as *const _ as usize
-        });
-        assert_eq!(112, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_sched as *const _ as usize
-        });
-        assert_eq!(113, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_pad as *const _ as usize
-        });
-        assert_eq!(120, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_uid as *const _ as usize
-        });
-        assert_eq!(124, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_gid as *const _ as usize
-        });
-        assert_eq!(128, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_pid as *const _ as usize
-        });
-        assert_eq!(132, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_ppid as *const _ as usize
-        });
-        assert_eq!(136, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_btime as *const _ as usize
-        });
-        assert_eq!(144, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_etime as *const _ as usize
-        });
-        assert_eq!(152, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_utime as *const _ as usize
-        });
-        assert_eq!(160, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_stime as *const _ as usize
-        });
-        assert_eq!(168, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_minflt as *const _ as usize
-        });
-        assert_eq!(176, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_majflt as *const _ as usize
-        });
-        assert_eq!(184, unsafe {
-            &(*(std::ptr::null::<taskstats>())).coremem as *const _ as usize
-        });
-        assert_eq!(192, unsafe {
-            &(*(std::ptr::null::<taskstats>())).virtmem as *const _ as usize
-        });
-        assert_eq!(200, unsafe {
-            &(*(std::ptr::null::<taskstats>())).hiwater_rss as *const _ as usize
-        });
-        assert_eq!(208, unsafe {
-            &(*(std::ptr::null::<taskstats>())).hiwater_vm as *const _ as usize
-        });
-        assert_eq!(216, unsafe {
-            &(*(std::ptr::null::<taskstats>())).read_char as *const _ as usize
-        });
-        assert_eq!(224, unsafe {
-            &(*(std::ptr::null::<taskstats>())).write_char as *const _ as usize
-        });
-        assert_eq!(232, unsafe {
-            &(*(std::ptr::null::<taskstats>())).read_syscalls as *const _ as usize
-        });
-        assert_eq!(240, unsafe {
-            &(*(std::ptr::null::<taskstats>())).write_syscalls as *const _ as usize
-        });
-        assert_eq!(248, unsafe {
-            &(*(std::ptr::null::<taskstats>())).read_bytes as *const _ as usize
-        });
-        assert_eq!(256, unsafe {
-            &(*(std::ptr::null::<taskstats>())).write_bytes as *const _ as usize
-        });
-        assert_eq!(264, unsafe {
-            &(*(std::ptr::null::<taskstats>())).cancelled_write_bytes as *const _ as usize
-        });
-        assert_eq!(272, unsafe {
-            &(*(std::ptr::null::<taskstats>())).nvcsw as *const _ as usize
-        });
-        assert_eq!(280, unsafe {
-            &(*(std::ptr::null::<taskstats>())).nivcsw as *const _ as usize
-        });
-        assert_eq!(288, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_utimescaled as *const _ as usize
-        });
-        assert_eq!(296, unsafe {
-            &(*(std::ptr::null::<taskstats>())).ac_stimescaled as *const _ as usize
-        });
-        assert_eq!(304, unsafe {
-            &(*(std::ptr::null::<taskstats>())).cpu_scaled_run_real_total as *const _ as usize
-        });
-        assert_eq!(312, unsafe {
-            &(*(std::ptr::null::<taskstats>())).freepages_count as *const _ as usize
-        });
-        assert_eq!(320, unsafe {
-            &(*(std::ptr::null::<taskstats>())).freepages_delay_total as *const _ as usize
-        });
+        assert!(ts.delays.cpu.delay_total.as_nanos() > 0);
+        assert!(ts.cpu.virtual_time_total.as_nanos() > 0);
     }
 }

Diff for: src/model.rs

@@ -22,7 +22,7 @@ pub const TASKSTATS_SIZE: usize = const_max(
 /// There are more (but may not much interested) fields in the original
 /// `struct taskstats` and they are accessible through obtaining the original
 /// struct by `TaskStats#inner()`.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 pub struct TaskStats {
     pub(crate) inner_buf: [u8; TASKSTATS_SIZE],
     /// The target task ID