ANDROID: add support for Clang's Control Flow Integrity (CFI)

This change adds the CONFIG_CFI_CLANG option, CFI error handling,
and a faster look-up table for cross module CFI checks.

Bug: 145210207
Change-Id: I118303de50114ca6f85d89a7d69c5cbc47e2f5c0
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

include/linux/module.h

@@ -22,6 +22,7 @@
 #include <linux/error-injection.h>
 #include <linux/tracepoint-defs.h>
 #include <linux/srcu.h>
+#include <linux/cfi.h>
 
 #include <linux/percpu.h>
 #include <asm/module.h>
@@ -365,6 +366,10 @@ struct module {
 	const s32 *crcs;
 	unsigned int num_syms;
 
+#ifdef CONFIG_CFI_CLANG
+	cfi_check_fn cfi_check;
+#endif
+
 	/* Kernel parameters. */
 #ifdef CONFIG_SYSFS
 	struct mutex param_lock;