From 3e7fc94ca779fc91c0131221222d81b1c217441f Mon Sep 17 00:00:00 2001
From: Shuocheng Wang <wangshch5@outlook.com>
Date: Mon, 19 Jul 2021 10:49:30 +0800
Subject: [PATCH] Fix the return value of sched_getaffinity.

---
 src/libos/src/sched/cpu_set.rs  | 4 +++-
 src/libos/src/sched/syscalls.rs | 5 -----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/libos/src/sched/cpu_set.rs b/src/libos/src/sched/cpu_set.rs
index bdedf415..f0175940 100644
--- a/src/libos/src/sched/cpu_set.rs
+++ b/src/libos/src/sched/cpu_set.rs
@@ -20,8 +20,10 @@ pub struct CpuSet {
 
 impl CpuSet {
     /// Returns the length of a CPU set in bytes.
+    ///
+    /// The length must be an integer multiple of sizeof(long) in Linux.
     pub fn len() -> usize {
-        align_up(Self::ncores(), 8) / 8
+        align_up(align_up(Self::ncores(), 8) / 8, 8)
     }
 
     /// Returns the number CPU of cores in a CPU set.
diff --git a/src/libos/src/sched/syscalls.rs b/src/libos/src/sched/syscalls.rs
index 13dd128f..e3741b09 100644
--- a/src/libos/src/sched/syscalls.rs
+++ b/src/libos/src/sched/syscalls.rs
@@ -14,11 +14,6 @@ pub fn do_sched_getaffinity(pid: pid_t, buf_size: size_t, buf_ptr: *mut u8) -> R
             return_errno!(EINVAL, "buf size is not big enough");
         }
 
-        // Linux stores the cpumask in an array of "unsigned long" so the buffer needs to be
-        // multiple of unsigned long. However, Occlum doesn't have this restriction.
-        if (buf_size & (std::mem::size_of::<u64>() - 1) != 0) {
-            warn!("cpuset buf size is not a multiple of unsigned long");
-        }
         CpuSet::len()
     };
     let mut buf_slice = {