diff --git a/kernel/src/syscall/madvise.rs b/kernel/src/syscall/madvise.rs
index 84b1a092d..85d85cfcf 100644
--- a/kernel/src/syscall/madvise.rs
+++ b/kernel/src/syscall/madvise.rs
@@ -20,7 +20,7 @@ pub fn sys_madvise(
     if start % PAGE_SIZE != 0 {
         return_errno_with_message!(Errno::EINVAL, "the start address should be page aligned");
     }
-    if len > usize::MAX - PAGE_SIZE + 1 {
+    if len > isize::MAX as usize {
         return_errno_with_message!(Errno::EINVAL, "len align overflow");
     }
     if len == 0 {
diff --git a/kernel/src/syscall/mprotect.rs b/kernel/src/syscall/mprotect.rs
index 5543db9ac..62fd7c8c5 100644
--- a/kernel/src/syscall/mprotect.rs
+++ b/kernel/src/syscall/mprotect.rs
@@ -22,7 +22,7 @@ pub fn sys_mprotect(addr: Vaddr, len: usize, perms: u64, ctx: &Context) -> Resul
     if len == 0 {
         return Ok(SyscallReturn::Return(0));
     }
-    if len > usize::MAX - PAGE_SIZE + 1 {
+    if len > isize::MAX as usize {
         return_errno_with_message!(Errno::ENOMEM, "len align overflow");
     }
 
diff --git a/kernel/src/syscall/munmap.rs b/kernel/src/syscall/munmap.rs
index fea54ff65..1e4498071 100644
--- a/kernel/src/syscall/munmap.rs
+++ b/kernel/src/syscall/munmap.rs
@@ -14,7 +14,7 @@ pub fn sys_munmap(addr: Vaddr, len: usize, ctx: &Context) -> Result<SyscallRetur
     if len == 0 {
         return_errno_with_message!(Errno::EINVAL, "munmap len cannot be zero");
     }
-    if len > usize::MAX - PAGE_SIZE + 1 {
+    if len > isize::MAX as usize {
         return_errno_with_message!(Errno::ENOMEM, "munmap len align overflow");
     }