1 files changed, 73 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/hugetlb_fault_after_madv.c b/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
new file mode 100644
index 000000000000..73b81c632366
--- /dev/null
+++ b/tools/testing/selftests/mm/hugetlb_fault_after_madv.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "vm_util.h"
+#include "../kselftest.h"
+
+#define MMAP_SIZE (1 << 21)
+#define INLOOP_ITER 100
+
+char *huge_ptr;
+
+/* Touch the memory while it is being madvised() */
+void *touch(void *unused)
+{
+	char *ptr = (char *)huge_ptr;
+
+	for (int i = 0; i < INLOOP_ITER; i++)
+		ptr[0] = '.';
+
+	return NULL;
+}
+
+void *madv(void *unused)
+{
+	usleep(rand() % 10);
+
+	for (int i = 0; i < INLOOP_ITER; i++)
+		madvise(huge_ptr, MMAP_SIZE, MADV_DONTNEED);
+
+	return NULL;
+}
+
+int main(void)
+{
+	unsigned long free_hugepages;
+	pthread_t thread1, thread2;
+	/*
+	 * On kernel 6.4, we are able to reproduce the problem with ~1000
+	 * interactions
+	 */
+	int max = 10000;
+
+	srand(getpid());
+
+	free_hugepages = get_free_hugepages();
+	if (free_hugepages != 1) {
+		ksft_exit_skip("This test needs one and only one page to execute. Got %lu\n",
+			       free_hugepages);
+	}
+
+	while (max--) {
+		huge_ptr = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE,
+				MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
+				-1, 0);
+
+		if ((unsigned long)huge_ptr == -1)
+			ksft_exit_skip("Failed to allocated huge page\n");
+
+		pthread_create(&thread1, NULL, madv, NULL);
+		pthread_create(&thread2, NULL, touch, NULL);
+
+		pthread_join(thread1, NULL);
+		pthread_join(thread2, NULL);
+		munmap(huge_ptr, MMAP_SIZE);
+	}
+
+	return KSFT_PASS;
+}