Merge tag 'riscv-for-linus-6.9-mw2' of git://git.kernel.org/pub/scm/linux/kernel...

[sfrench/cifs-2.6.git] / kernel / sched / membarrier.c

diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 703e8d80a576d171c410d14117000dd1fc47d2b0..809194cd779f42fa57759b731c52685a14744f83 100644 (file)
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -162,6 +162,9 @@
        | MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK                     \
        | MEMBARRIER_CMD_GET_REGISTRATIONS)
 
+static DEFINE_MUTEX(membarrier_ipi_mutex);
+#define SERIALIZE_IPI() guard(mutex)(&membarrier_ipi_mutex)
+
 static void ipi_mb(void *info)
 {
        smp_mb();       /* IPIs should be serializing but paranoid. */
@@ -259,6 +262,7 @@ static int membarrier_global_expedited(void)
        if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
                return -ENOMEM;
 
+       SERIALIZE_IPI();
        cpus_read_lock();
        rcu_read_lock();
        for_each_online_cpu(cpu) {
@@ -352,6 +356,7 @@ static int membarrier_private_expedited(int flags, int cpu_id)
        if (cpu_id < 0 && !zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
                return -ENOMEM;
 
+       SERIALIZE_IPI();
        cpus_read_lock();
 
        if (cpu_id >= 0) {
@@ -465,6 +470,7 @@ static int sync_runqueues_membarrier_state(struct mm_struct *mm)
         * between threads which are users of @mm has its membarrier state
         * updated.
         */
+       SERIALIZE_IPI();
        cpus_read_lock();
        rcu_read_lock();
        for_each_online_cpu(cpu) {