docs: add limitation of system calls that call copy_to_user()

Change-Id: If449c73f8d5949ab5526ea598b0f713ed4431157 Refs: #1514
2021-02-03 08:37:21 +09:00
parent 48b1d548f2
commit 866f5c51a0
1 changed files with 6 additions and 0 deletions
--- a/docs/users.rst
+++ b/docs/users.rst
@ -214,3 +214,9 @@ Limitations
    ::

       sudo systemctl restart xos_hwb
+
+31. System calls can write the mcexec VMAs with PROT_WRITE flag not
+    set. This is because we never turn off PROT_WRITE of the mcexec
+    VMAs to circumvent the issue "set_host_vma(): do NOT read protect
+    Linux VMA".
+