diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
index 1cb90a435c5c..c233aae5eac9 100644
--- a/include/uapi/linux/rseq.h
+++ b/include/uapi/linux/rseq.h
@@ -139,6 +139,15 @@ struct rseq {
 	 */
 	__u32 node_id;
 
+	/*
+	 * Restartable sequences mm_cid field. Updated by the kernel. Read by
+	 * user-space with single-copy atomicity semantics. This field should
+	 * only be read by the thread which registered this data structure.
+	 * Aligned on 32-bit. Contains the current thread's concurrency ID
+	 * (allocated uniquely within a memory map).
+	 */
+	__u32 mm_cid;
+
 	/*
 	 * Flexible array member at end of structure, after last feature field.
 	 */
diff --git a/kernel/rseq.c b/kernel/rseq.c
index 193cfcc94ddc..9de6e35fe679 100644
--- a/kernel/rseq.c
+++ b/kernel/rseq.c
@@ -90,12 +90,15 @@ static int rseq_update_cpu_node_id(struct task_struct *t)
 	struct rseq __user *rseq = t->rseq;
 	u32 cpu_id = raw_smp_processor_id();
 	u32 node_id = cpu_to_node(cpu_id);
+	u32 mm_cid = task_mm_cid(t);
 
+	WARN_ON_ONCE((int) mm_cid < 0);
 	if (!user_write_access_begin(rseq, t->rseq_len))
 		goto efault;
 	unsafe_put_user(cpu_id, &rseq->cpu_id_start, efault_end);
 	unsafe_put_user(cpu_id, &rseq->cpu_id, efault_end);
 	unsafe_put_user(node_id, &rseq->node_id, efault_end);
+	unsafe_put_user(mm_cid, &rseq->mm_cid, efault_end);
 	/*
 	 * Additional feature fields added after ORIG_RSEQ_SIZE
 	 * need to be conditionally updated only if
@@ -113,7 +116,8 @@ efault:
 
 static int rseq_reset_rseq_cpu_node_id(struct task_struct *t)
 {
-	u32 cpu_id_start = 0, cpu_id = RSEQ_CPU_ID_UNINITIALIZED, node_id = 0;
+	u32 cpu_id_start = 0, cpu_id = RSEQ_CPU_ID_UNINITIALIZED, node_id = 0,
+	    mm_cid = 0;
 
 	/*
 	 * Reset cpu_id_start to its initial state (0).
@@ -132,6 +136,11 @@ static int rseq_reset_rseq_cpu_node_id(struct task_struct *t)
 	 */
 	if (put_user(node_id, &t->rseq->node_id))
 		return -EFAULT;
+	/*
+	 * Reset mm_cid to its initial state (0).
+	 */
+	if (put_user(mm_cid, &t->rseq->mm_cid))
+		return -EFAULT;
 	/*
 	 * Additional feature fields added after ORIG_RSEQ_SIZE
 	 * need to be conditionally reset only if