objtool: Move ANNOTATE* macros to annotate.h

In preparation for using the objtool annotation macros in higher-level
objtool.h macros like UNWIND_HINT, move them to their own file.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

1 files changed, 109 insertions, 0 deletions

diff --git a/include/linux/annotate.h b/include/linux/annotate.h
new file mode 100644
index 000000000000..ccb445496331
--- /dev/null
+++ b/include/linux/annotate.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_ANNOTATE_H
+#define _LINUX_ANNOTATE_H
+
+#include <linux/objtool_types.h>
+
+#ifdef CONFIG_OBJTOOL
+
+#ifndef __ASSEMBLY__
+
+#define __ASM_ANNOTATE(label, type)					\
+	".pushsection .discard.annotate_insn,\"M\",@progbits,8\n\t"	\
+	".long " __stringify(label) " - .\n\t"				\
+	".long " __stringify(type) "\n\t"				\
+	".popsection\n\t"
+
+#define ASM_ANNOTATE(type)						\
+	"911:\n\t"							\
+	__ASM_ANNOTATE(911b, type)
+
+#else /* __ASSEMBLY__ */
+
+.macro ANNOTATE type:req
+.Lhere_\@:
+	.pushsection .discard.annotate_insn,"M",@progbits,8
+	.long	.Lhere_\@ - .
+	.long	\type
+	.popsection
+.endm
+
+#endif /* __ASSEMBLY__ */
+
+#else /* !CONFIG_OBJTOOL */
+#ifndef __ASSEMBLY__
+#define __ASM_ANNOTATE(label, type) ""
+#define ASM_ANNOTATE(type)
+#else /* __ASSEMBLY__ */
+.macro ANNOTATE type:req
+.endm
+#endif /* __ASSEMBLY__ */
+#endif /* !CONFIG_OBJTOOL */
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Annotate away the various 'relocation to !ENDBR` complaints; knowing that
+ * these relocations will never be used for indirect calls.
+ */
+#define ANNOTATE_NOENDBR		ASM_ANNOTATE(ANNOTYPE_NOENDBR)
+#define ANNOTATE_NOENDBR_SYM(sym)	asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOENDBR))
+
+/*
+ * This should be used immediately before an indirect jump/call. It tells
+ * objtool the subsequent indirect jump/call is vouched safe for retpoline
+ * builds.
+ */
+#define ANNOTATE_RETPOLINE_SAFE		ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
+/*
+ * See linux/instrumentation.h
+ */
+#define ANNOTATE_INSTR_BEGIN(label)	__ASM_ANNOTATE(label, ANNOTYPE_INSTR_BEGIN)
+#define ANNOTATE_INSTR_END(label)	__ASM_ANNOTATE(label, ANNOTYPE_INSTR_END)
+/*
+ * objtool annotation to ignore the alternatives and only consider the original
+ * instruction(s).
+ */
+#define ANNOTATE_IGNORE_ALTERNATIVE	ASM_ANNOTATE(ANNOTYPE_IGNORE_ALTS)
+/*
+ * This macro indicates that the following intra-function call is valid.
+ * Any non-annotated intra-function call will cause objtool to issue a warning.
+ */
+#define ANNOTATE_INTRA_FUNCTION_CALL	ASM_ANNOTATE(ANNOTYPE_INTRA_FUNCTION_CALL)
+/*
+ * Use objtool to validate the entry requirement that all code paths do
+ * VALIDATE_UNRET_END before RET.
+ *
+ * NOTE: The macro must be used at the beginning of a global symbol, otherwise
+ * it will be ignored.
+ */
+#define ANNOTATE_UNRET_BEGIN		ASM_ANNOTATE(ANNOTYPE_UNRET_BEGIN)
+/*
+ * This should be used to refer to an instruction that is considered
+ * terminating, like a noreturn CALL or UD2 when we know they are not -- eg
+ * WARN using UD2.
+ */
+#define ANNOTATE_REACHABLE(label)	__ASM_ANNOTATE(label, ANNOTYPE_REACHABLE)
+/*
+ * This should not be used; it annotates away CFI violations. There are a few
+ * valid use cases like kexec handover to the next kernel image, and there is
+ * no security concern there.
+ *
+ * There are also a few real issues annotated away, like EFI because we can't
+ * control the EFI code.
+ */
+#define ANNOTATE_NOCFI_SYM(sym)		asm(__ASM_ANNOTATE(sym, ANNOTYPE_NOCFI))
+
+#else /* __ASSEMBLY__ */
+#define ANNOTATE_NOENDBR		ANNOTATE type=ANNOTYPE_NOENDBR
+#define ANNOTATE_RETPOLINE_SAFE		ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
+/*	ANNOTATE_INSTR_BEGIN		ANNOTATE type=ANNOTYPE_INSTR_BEGIN */
+/*	ANNOTATE_INSTR_END		ANNOTATE type=ANNOTYPE_INSTR_END */
+#define ANNOTATE_IGNORE_ALTERNATIVE	ANNOTATE type=ANNOTYPE_IGNORE_ALTS
+#define ANNOTATE_INTRA_FUNCTION_CALL	ANNOTATE type=ANNOTYPE_INTRA_FUNCTION_CALL
+#define ANNOTATE_UNRET_BEGIN		ANNOTATE type=ANNOTYPE_UNRET_BEGIN
+#define ANNOTATE_REACHABLE		ANNOTATE type=ANNOTYPE_REACHABLE
+#define ANNOTATE_NOCFI_SYM		ANNOTATE type=ANNOTYPE_NOCFI
+#endif /* __ASSEMBLY__ */
+
+#endif /* _LINUX_ANNOTATE_H */