__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.
*/
char end[];
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
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).
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
* t->rseq_len != ORIG_RSEQ_SIZE.