runtime-rs: fixed bug on core-sched error handling

Kernel code returns -errno, this should check negative values.

Fixes: #4429
Signed-off-by: Ji-Xinyou <jerryji0414@outlook.com>

src/runtime-rs/crates/shim/src/core_sched.rs

@@ -38,7 +38,7 @@ pub const PR_SCHED_CORE_SHARE_FROM: usize = 3;
 pub fn core_sched_create(pidtype: usize) -> Result<(), Errno> {
     let errno = unsafe { nix::libc::prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, 0, pidtype, 0) };
     if errno != 0 {
-        Err(nix::errno::Errno::from_i32(errno))
+        Err(nix::errno::Errno::from_i32(-errno))
     } else {
         Ok(())
     }
@@ -50,7 +50,7 @@ pub fn core_sched_share_from(pid: usize, pidtype: usize) -> Result<(), Errno> {
     let errno =
         unsafe { nix::libc::prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, pid, pidtype, 0) };
     if errno != 0 {
-        Err(nix::errno::Errno::from_i32(errno))
+        Err(nix::errno::Errno::from_i32(-errno))
     } else {
         Ok(())
     }
@@ -87,18 +87,15 @@ mod tests {
             // therefore it does not make sense to assert a successful prctl call
             // but we can still make sure that the return value is a possible value
             let e = core_sched_create(PROCESS_GROUP);
-            match e {
-                Err(errno) => {
-                    if errno != EINVAL
-                        && errno != ENODEV
-                        && errno != ENOMEM
-                        && errno != EPERM
-                        && errno != ESRCH
-                    {
-                        panic!("impossible return value {:?}", errno);
-                    }
+            if let Err(errno) = e {
+                if errno != EINVAL
+                    && errno != ENODEV
+                    && errno != ENOMEM
+                    && errno != EPERM
+                    && errno != ESRCH
+                {
+                    panic!("impossible return value {:?}", errno);
                 }
-                Ok(()) => {}
             }
         }
     }

src/runtime-rs/crates/shim/src/shim_run.rs

@@ -8,7 +8,6 @@ use std::os::unix::io::RawFd;
 
 use anyhow::{Context, Result};
 use kata_sys_util::spec::get_bundle_path;
-use nix::errno::Errno;
 
 use crate::{
     core_sched, logger,
@@ -71,14 +70,11 @@ fn get_server_fd() -> Result<RawFd> {
 }
 
 // TODO: currently we log a warning on fail (i.e. kernel version < 5.14), maybe just exit
-fn try_core_sched() -> Result<(), Errno> {
+// TODO: more test on higher version of kernel
+fn try_core_sched() -> Result<()> {
     if let Ok(v) = std::env::var("SCHED_CORE") {
-        info!(
-            sl!(),
-            "containerd wants to enable core scheduling, SCHED_CORE={}(expected 1)", v
-        );
         if !v.is_empty() {
-            return core_sched::core_sched_create(core_sched::PROCESS_GROUP);
+            core_sched::core_sched_create(core_sched::PROCESS_GROUP)?
         }
     }
     Ok(())