1 files changed, 134 insertions, 0 deletions
diff --git a/mm/hugetlb_sysctl.c b/mm/hugetlb_sysctl.c
new file mode 100644
index 000000000000..bd3077150542
--- /dev/null
+++ b/mm/hugetlb_sysctl.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HugeTLB sysfs interfaces.
+ * (C) Nadia Yvette Chambers, April 2004
+ */
+
+#include <linux/sysctl.h>
+
+#include "hugetlb_internal.h"
+
+#ifdef CONFIG_SYSCTL
+static int proc_hugetlb_doulongvec_minmax(const struct ctl_table *table, int write,
+					  void *buffer, size_t *length,
+					  loff_t *ppos, unsigned long *out)
+{
+	struct ctl_table dup_table;
+
+	/*
+	 * In order to avoid races with __do_proc_doulongvec_minmax(), we
+	 * can duplicate the @table and alter the duplicate of it.
+	 */
+	dup_table = *table;
+	dup_table.data = out;
+
+	return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos);
+}
+
+static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
+			 const struct ctl_table *table, int write,
+			 void *buffer, size_t *length, loff_t *ppos)
+{
+	struct hstate *h = &default_hstate;
+	unsigned long tmp = h->max_huge_pages;
+	int ret;
+
+	if (!hugepages_supported())
+		return -EOPNOTSUPP;
+
+	ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos,
+					     &tmp);
+	if (ret)
+		goto out;
+
+	if (write)
+		ret = __nr_hugepages_store_common(obey_mempolicy, h,
+						  NUMA_NO_NODE, tmp, *length);
+out:
+	return ret;
+}
+
+static int hugetlb_sysctl_handler(const struct ctl_table *table, int write,
+			  void *buffer, size_t *length, loff_t *ppos)
+{
+
+	return hugetlb_sysctl_handler_common(false, table, write,
+							buffer, length, ppos);
+}
+
+#ifdef CONFIG_NUMA
+static int hugetlb_mempolicy_sysctl_handler(const struct ctl_table *table, int write,
+			  void *buffer, size_t *length, loff_t *ppos)
+{
+	return hugetlb_sysctl_handler_common(true, table, write,
+							buffer, length, ppos);
+}
+#endif /* CONFIG_NUMA */
+
+static int hugetlb_overcommit_handler(const struct ctl_table *table, int write,
+		void *buffer, size_t *length, loff_t *ppos)
+{
+	struct hstate *h = &default_hstate;
+	unsigned long tmp;
+	int ret;
+
+	if (!hugepages_supported())
+		return -EOPNOTSUPP;
+
+	tmp = h->nr_overcommit_huge_pages;
+
+	if (write && hstate_is_gigantic_no_runtime(h))
+		return -EINVAL;
+
+	ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos,
+					     &tmp);
+	if (ret)
+		goto out;
+
+	if (write) {
+		spin_lock_irq(&hugetlb_lock);
+		h->nr_overcommit_huge_pages = tmp;
+		spin_unlock_irq(&hugetlb_lock);
+	}
+out:
+	return ret;
+}
+
+static const struct ctl_table hugetlb_table[] = {
+	{
+		.procname	= "nr_hugepages",
+		.data		= NULL,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= hugetlb_sysctl_handler,
+	},
+#ifdef CONFIG_NUMA
+	{
+		.procname       = "nr_hugepages_mempolicy",
+		.data           = NULL,
+		.maxlen         = sizeof(unsigned long),
+		.mode           = 0644,
+		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
+	},
+#endif
+	{
+		.procname	= "hugetlb_shm_group",
+		.data		= &sysctl_hugetlb_shm_group,
+		.maxlen		= sizeof(gid_t),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "nr_overcommit_hugepages",
+		.data		= NULL,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= hugetlb_overcommit_handler,
+	},
+};
+
+void __init hugetlb_sysctl_init(void)
+{
+	register_sysctl_init("vm", hugetlb_table);
+}
+#endif /* CONFIG_SYSCTL */