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-rw-r--r--arch/arm/lib/asmdefs.h98
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/arm/lib/asmdefs.h b/arch/arm/lib/asmdefs.h
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+/* SPDX-License-Identifier: MIT */
+/*
+ * Macros for asm code.
+ *
+ * Copyright (c) 2019, Arm Limited.
+ */
+
+#ifndef _ASMDEFS_H
+#define _ASMDEFS_H
+
+#if defined(__aarch64__)
+
+/* Branch Target Identitication support. */
+#define BTI_C hint 34
+#define BTI_J hint 36
+/* Return address signing support (pac-ret). */
+#define PACIASP hint 25; .cfi_window_save
+#define AUTIASP hint 29; .cfi_window_save
+
+/* GNU_PROPERTY_AARCH64_* macros from elf.h. */
+#define FEATURE_1_AND 0xc0000000
+#define FEATURE_1_BTI 1
+#define FEATURE_1_PAC 2
+
+/* Add a NT_GNU_PROPERTY_TYPE_0 note. */
+#define GNU_PROPERTY(type, value) \
+ .section .note.gnu.property, "a"; \
+ .p2align 3; \
+ .word 4; \
+ .word 16; \
+ .word 5; \
+ .asciz "GNU"; \
+ .word type; \
+ .word 4; \
+ .word value; \
+ .word 0; \
+ .text
+
+/* If set then the GNU Property Note section will be added to
+ mark objects to support BTI and PAC-RET. */
+#ifndef WANT_GNU_PROPERTY
+#define WANT_GNU_PROPERTY 1
+#endif
+
+#if WANT_GNU_PROPERTY
+/* Add property note with supported features to all asm files. */
+GNU_PROPERTY (FEATURE_1_AND, FEATURE_1_BTI|FEATURE_1_PAC)
+#endif
+
+#define ENTRY_ALIGN(name, alignment) \
+ .global name; \
+ .type name,%function; \
+ .align alignment; \
+ name: \
+ .cfi_startproc; \
+ BTI_C;
+
+#else
+
+#define END_FILE
+
+#define ENTRY_ALIGN(name, alignment) \
+ .global name; \
+ .type name,%function; \
+ .align alignment; \
+ name: \
+ .cfi_startproc;
+
+#endif
+
+#define ENTRY(name) ENTRY_ALIGN(name, 6)
+
+#define ENTRY_ALIAS(name) \
+ .global name; \
+ .type name,%function; \
+ name:
+
+#define END(name) \
+ .cfi_endproc; \
+ .size name, .-name;
+
+#define L(l) .L ## l
+
+#ifdef __ILP32__
+ /* Sanitize padding bits of pointer arguments as per aapcs64 */
+#define PTR_ARG(n) mov w##n, w##n
+#else
+#define PTR_ARG(n)
+#endif
+
+#ifdef __ILP32__
+ /* Sanitize padding bits of size arguments as per aapcs64 */
+#define SIZE_ARG(n) mov w##n, w##n
+#else
+#define SIZE_ARG(n)
+#endif
+
+#endif