1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/intrinsics.c b/drivers/firmware/efi/libstub/intrinsics.c
new file mode 100644
index 000000000000..418cd2e6dccc
--- /dev/null
+++ b/drivers/firmware/efi/libstub/intrinsics.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include <asm/string.h>
+
+#include "efistub.h"
+
+#ifdef CONFIG_KASAN
+#undef memcpy
+#undef memmove
+#undef memset
+void *__memcpy(void *__dest, const void *__src, size_t __n) __alias(memcpy);
+void *__memmove(void *__dest, const void *__src, size_t count) __alias(memmove);
+void *__memset(void *s, int c, size_t count) __alias(memset);
+#endif
+
+static void *efistub_memmove(u8 *dst, const u8 *src, size_t len)
+{
+	if (src > dst || dst >= (src + len))
+		for (size_t i = 0; i < len; i++)
+			dst[i] = src[i];
+	else
+		for (ssize_t i = len - 1; i >= 0; i--)
+			dst[i] = src[i];
+
+	return dst;
+}
+
+static void *efistub_memset(void *dst, int c, size_t len)
+{
+	for (u8 *d = dst; len--; d++)
+		*d = c;
+
+	return dst;
+}
+
+void *memcpy(void *dst, const void *src, size_t len)
+{
+	if (efi_table_attr(efi_system_table, boottime) == NULL)
+		return efistub_memmove(dst, src, len);
+
+	efi_bs_call(copy_mem, dst, src, len);
+	return dst;
+}
+
+extern void *memmove(void *dst, const void *src, size_t len) __alias(memcpy);
+
+void *memset(void *dst, int c, size_t len)
+{
+	if (efi_table_attr(efi_system_table, boottime) == NULL)
+		return efistub_memset(dst, c, len);
+
+	efi_bs_call(set_mem, dst, len, c & U8_MAX);
+	return dst;
+}
+
+/**
+ * memcmp - Compare two areas of memory
+ * @cs: One area of memory
+ * @ct: Another area of memory
+ * @count: The size of the area.
+ */
+#undef memcmp
+int memcmp(const void *cs, const void *ct, size_t count)
+{
+	const unsigned char *su1, *su2;
+	int res = 0;
+
+	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
+		if ((res = *su1 - *su2) != 0)
+			break;
+	return res;
+}