Test IBT externalization method

Signed-off-by: Marcos Paulo de Souza <[email protected]>

testsuite/small/Modules.symvers

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+0x00000000	crc32c	lib/libcrc32c	EXPORT_SYMBOL	

testsuite/small/ibt-1.c

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+/* { dg-options "-DCE_EXTRACT_FUNCTIONS=f -DCE_RENAME_SYMBOLS -include ../testsuite/small/linux/livepatch.h -DCE_SYMVERS_PATH=../testsuite/small/Modules.symvers -DKBUILD_MODNAME=crc32c -D__USE_IBT__" } */
+
+#include <linux/types.h>
+
+typedef unsigned int u32;
+
+u32 crc32c(u32 crc, const void *address, unsigned int length);
+
+int f(void)
+{
+	u32 lcrc = 0;
+	void *addr = 0;
+	unsigned int len = 0;
+
+	(void)crc32c(lcrc, addr, len);
+	return 0;
+}
+
+/* { dg-final { scan-tree-dump "u32 klpe_crc32c" } } */
+/* { dg-final { scan-tree-dump "KLP_RELOC_SYMBOL\(crc32c, crc32c, crc32c\)" } } */
+/* { dg-final { scan-tree-dump-not "\(\*klpe_crc32c\)" } } */

testsuite/small/linux/livepatch.h

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+/**
+ * KLP_RELOC_SYMBOL_POS - define relocation for external symbols
+ *
+ * @LP_OBJ_NAME: name of the livepatched object where the symbol is needed
+ * @SYM_OBJ_NAME: name of the object where the symbol exists
+ * @SYM_NAME: symbol name
+ * @SYM_POS: position of the symbol in SYM_OBJ when there are more
+ *       symbols of the same name.
+ *
+ * Use for annotating external symbols used in livepatches which are
+ * not exported in vmlinux or are in livepatched modules, see
+ * Documentation/livepatch/module-elf-format.rst
+ */
+#define KLP_RELOC_SYMBOL_POS(LP_OBJ_NAME, SYM_OBJ_NAME, SYM_NAME, SYM_POS)	\
+	asm("\".klp.sym.rela." #LP_OBJ_NAME "." #SYM_OBJ_NAME "." #SYM_NAME "," #SYM_POS "\"")
+
+#define KLP_RELOC_SYMBOL(LP_OBJ_NAME, SYM_OBJ_NAME, SYM_NAME)	\
+	KLP_RELOC_SYMBOL_POS(LP_OBJ_NAME, SYM_OBJ_NAME, SYM_NAME, 0)