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-rw-r--r--arch/x86/mm/testmmiotrace.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c
index 8565d944f7cf..38868adf07ea 100644
--- a/arch/x86/mm/testmmiotrace.c
+++ b/arch/x86/mm/testmmiotrace.c
@@ -90,6 +90,27 @@ static void do_test(unsigned long size)
iounmap(p);
}
+/*
+ * Tests how mmiotrace behaves in face of multiple ioremap / iounmaps in
+ * a short time. We had a bug in deferred freeing procedure which tried
+ * to free this region multiple times (ioremap can reuse the same address
+ * for many mappings).
+ */
+static void do_test_bulk_ioremapping(void)
+{
+ void __iomem *p;
+ int i;
+
+ for (i = 0; i < 10; ++i) {
+ p = ioremap_nocache(mmio_address, PAGE_SIZE);
+ if (p)
+ iounmap(p);
+ }
+
+ /* Force freeing. If it will crash we will know why. */
+ synchronize_rcu();
+}
+
static int __init init(void)
{
unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
@@ -104,6 +125,7 @@ static int __init init(void)
"and writing 16 kB of rubbish in there.\n",
size >> 10, mmio_address);
do_test(size);
+ do_test_bulk_ioremapping();
pr_info("All done.\n");
return 0;
}