[Devel] [PATCH hci-8.1 1/2] mempolicy: prohibit mbind and set_mempolicy_home_node in VE

[Konstantin Khorenko]

A CT is meant to see a kernel without NUMA support: in a non-super VE
the NUMA API syscalls return -ENOSYS, as they do in a kernel built
without CONFIG_NUMA.

Return -ENOSYS from mbind(2) and set_mempolicy_home_node(2) at the
start of the handler, before any argument check, as the other NUMA API
syscalls do.

Fixes: a803a5b2ea97 ("mempolicy: prohibit all NUMA API syscalls in VE")
https://virtuozzo.atlassian.net/browse/VSTOR-153679

Feature: mm: prohibit NUMA API inside CT
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 mm/mempolicy.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 3255d3e987180..9b2a32ef92949 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1584,6 +1584,9 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le
 	int err = -ENOENT;
 	VMA_ITERATOR(vmi, mm, start);
 
+	if (!ve_is_super(get_exec_env()))
+		return -ENOSYS;
+
 	start = untagged_addr(start);
 	if (start & ~PAGE_MASK)
 		return -EINVAL;
@@ -1645,6 +1648,9 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
 		unsigned long, mode, const unsigned long __user *, nmask,
 		unsigned long, maxnode, unsigned int, flags)
 {
+	if (!ve_is_super(get_exec_env()))
+		return -ENOSYS;
+
 	return kernel_mbind(start, len, mode, nmask, maxnode, flags);
 }
 

-- 
2.43.0