Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/memcat_p.c b/lib/memcat_p.c
new file mode 100644
index 0000000..b810fbc
--- /dev/null
+++ b/lib/memcat_p.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/slab.h>
+
+/*
+ * Merge two NULL-terminated pointer arrays into a newly allocated
+ * array, which is also NULL-terminated. Nomenclature is inspired by
+ * memset_p() and memcat() found elsewhere in the kernel source tree.
+ */
+void **__memcat_p(void **a, void **b)
+{
+ void **p = a, **new;
+ int nr;
+
+ /* count the elements in both arrays */
+ for (nr = 0, p = a; *p; nr++, p++)
+ ;
+ for (p = b; *p; nr++, p++)
+ ;
+ /* one for the NULL-terminator */
+ nr++;
+
+ new = kmalloc_array(nr, sizeof(void *), GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+ /* nr -> last index; p points to NULL in b[] */
+ for (nr--; nr >= 0; nr--, p = p == b ? &a[nr] : p - 1)
+ new[nr] = *p;
+
+ return new;
+}
+EXPORT_SYMBOL_GPL(__memcat_p);
+