[PATCH v6 02/33] objtool: arm64: Add base definition for arm64 backend
From: Chen Zhongjin
Date: Wed Jun 22 2022 - 21:51:56 EST
Provide needed definitions for a new architecture instruction decoder.
No proper decoding is done yet.
Signed-off-by: Julien Thierry <jthierry@xxxxxxxxxx>
Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx>
---
tools/objtool/Makefile | 4 +
tools/objtool/arch/arm64/Build | 8 +
tools/objtool/arch/arm64/decode.c | 138 ++++++++++++++++++
.../arch/arm64/include/arch/cfi_regs.h | 14 ++
tools/objtool/arch/arm64/include/arch/elf.h | 12 ++
.../arch/arm64/include/arch/endianness.h | 9 ++
.../objtool/arch/arm64/include/arch/special.h | 22 +++
tools/objtool/arch/arm64/special.c | 21 +++
8 files changed, 228 insertions(+)
create mode 100644 tools/objtool/arch/arm64/Build
create mode 100644 tools/objtool/arch/arm64/decode.c
create mode 100644 tools/objtool/arch/arm64/include/arch/cfi_regs.h
create mode 100644 tools/objtool/arch/arm64/include/arch/elf.h
create mode 100644 tools/objtool/arch/arm64/include/arch/endianness.h
create mode 100644 tools/objtool/arch/arm64/include/arch/special.h
create mode 100644 tools/objtool/arch/arm64/special.c
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 2b97720ab608..3f7c7b54c741 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -45,6 +45,10 @@ ifeq ($(SRCARCH),x86)
BUILD_ORC := y
endif
+ifeq ($(SRCARCH),arm64)
+ CFLAGS += -Wno-nested-externs
+endif
+
export BUILD_ORC
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include
diff --git a/tools/objtool/arch/arm64/Build b/tools/objtool/arch/arm64/Build
new file mode 100644
index 000000000000..f3de3a50d541
--- /dev/null
+++ b/tools/objtool/arch/arm64/Build
@@ -0,0 +1,8 @@
+objtool-y += special.o
+objtool-y += decode.o
+
+objtool-y += libhweight.o
+
+$(OUTPUT)arch/arm64/libhweight.o: ../lib/hweight.c FORCE
+ $(call rule_mkdir)
+ $(call if_changed_dep,cc_o_c)
diff --git a/tools/objtool/arch/arm64/decode.c b/tools/objtool/arch/arm64/decode.c
new file mode 100644
index 000000000000..afe22c4593c8
--- /dev/null
+++ b/tools/objtool/arch/arm64/decode.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include <asm/insn.h>
+
+#include <objtool/check.h>
+#include <objtool/arch.h>
+#include <objtool/elf.h>
+#include <objtool/warn.h>
+#include <objtool/builtin.h>
+#include <arch/cfi_regs.h>
+
+#include "../../../arch/arm64/lib/insn.c"
+
+bool arch_callee_saved_reg(unsigned char reg)
+{
+ switch (reg) {
+ case AARCH64_INSN_REG_19:
+ case AARCH64_INSN_REG_20:
+ case AARCH64_INSN_REG_21:
+ case AARCH64_INSN_REG_22:
+ case AARCH64_INSN_REG_23:
+ case AARCH64_INSN_REG_24:
+ case AARCH64_INSN_REG_25:
+ case AARCH64_INSN_REG_26:
+ case AARCH64_INSN_REG_27:
+ case AARCH64_INSN_REG_28:
+ case AARCH64_INSN_REG_FP:
+ case AARCH64_INSN_REG_LR:
+ return true;
+ default:
+ return false;
+ }
+}
+
+void arch_initial_func_cfi_state(struct cfi_init_state *state)
+{
+ int i;
+
+ for (i = 0; i < CFI_NUM_REGS; i++) {
+ state->regs[i].base = CFI_UNDEFINED;
+ state->regs[i].offset = 0;
+ }
+
+ /* initial CFA (call frame address) */
+ state->cfa.base = CFI_SP;
+ state->cfa.offset = 0;
+}
+
+unsigned long arch_dest_reloc_offset(int addend)
+{
+ return addend;
+}
+
+unsigned long arch_jump_destination(struct instruction *insn)
+{
+ return insn->offset + insn->immediate;
+}
+
+const char *arch_nop_insn(int len)
+{
+ static u32 nop;
+
+ if (len != AARCH64_INSN_SIZE)
+ WARN("invalid NOP size: %d\n", len);
+
+ if (!nop)
+ nop = aarch64_insn_gen_nop();
+
+ return (const char *)&nop;
+}
+
+const char *arch_ret_insn(int len)
+{
+ static u32 ret;
+
+ if (len != AARCH64_INSN_SIZE)
+ WARN("invalid RET size: %d\n", len);
+
+ if (!ret) {
+ ret = aarch64_insn_gen_branch_reg(AARCH64_INSN_REG_LR,
+ AARCH64_INSN_BRANCH_RETURN);
+ }
+
+ return (const char *)&ret;
+}
+
+static int is_arm64(const struct elf *elf)
+{
+ switch (elf->ehdr.e_machine) {
+ case EM_AARCH64: //0xB7
+ return 1;
+ default:
+ WARN("unexpected ELF machine type %x",
+ elf->ehdr.e_machine);
+ return 0;
+ }
+}
+
+int arch_decode_hint_reg(u8 sp_reg, int *base)
+{
+ return -1;
+}
+
+int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
+ unsigned long offset, unsigned int maxlen,
+ unsigned int *len, enum insn_type *type,
+ unsigned long *immediate,
+ struct list_head *ops_list)
+{
+ const struct elf *elf = file->elf;
+ u32 insn;
+
+ if (!is_arm64(elf))
+ return -1;
+
+ if (maxlen < AARCH64_INSN_SIZE)
+ return 0;
+
+ *len = AARCH64_INSN_SIZE;
+ *immediate = 0;
+ *type = INSN_OTHER;
+
+ insn = *(u32 *)(sec->data->d_buf + offset);
+
+ switch (aarch64_get_insn_class(insn)) {
+ case AARCH64_INSN_CLS_UNKNOWN:
+ WARN("can't decode instruction at %s:0x%lx", sec->name, offset);
+ return -1;
+ default:
+ break;
+ }
+
+ return 0;
+}
diff --git a/tools/objtool/arch/arm64/include/arch/cfi_regs.h b/tools/objtool/arch/arm64/include/arch/cfi_regs.h
new file mode 100644
index 000000000000..a5185649686b
--- /dev/null
+++ b/tools/objtool/arch/arm64/include/arch/cfi_regs.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _OBJTOOL_CFI_REGS_H
+#define _OBJTOOL_CFI_REGS_H
+
+#include <asm/insn.h>
+
+#define CFI_BP AARCH64_INSN_REG_FP
+#define CFI_RA AARCH64_INSN_REG_LR
+#define CFI_SP AARCH64_INSN_REG_SP
+
+#define CFI_NUM_REGS 32
+
+#endif /* _OBJTOOL_CFI_REGS_H */
diff --git a/tools/objtool/arch/arm64/include/arch/elf.h b/tools/objtool/arch/arm64/include/arch/elf.h
new file mode 100644
index 000000000000..a59888a906b5
--- /dev/null
+++ b/tools/objtool/arch/arm64/include/arch/elf.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
+
+#ifndef _OBJTOOL_ARCH_ELF
+#define _OBJTOOL_ARCH_ELF
+
+#define R_NTYPE -1
+#define R_NONE R_AARCH64_NONE
+#define R_ABS64 R_AARCH64_ABS64
+#define R_REL32 R_AARCH64_PREL32
+#define R_PLT32 R_NTYPE
+
+#endif /* _OBJTOOL_ARCH_ELF */
diff --git a/tools/objtool/arch/arm64/include/arch/endianness.h b/tools/objtool/arch/arm64/include/arch/endianness.h
new file mode 100644
index 000000000000..7c362527da20
--- /dev/null
+++ b/tools/objtool/arch/arm64/include/arch/endianness.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _ARCH_ENDIANNESS_H
+#define _ARCH_ENDIANNESS_H
+
+#include <endian.h>
+
+#define __TARGET_BYTE_ORDER __LITTLE_ENDIAN
+
+#endif /* _ARCH_ENDIANNESS_H */
diff --git a/tools/objtool/arch/arm64/include/arch/special.h b/tools/objtool/arch/arm64/include/arch/special.h
new file mode 100644
index 000000000000..63a705c622a4
--- /dev/null
+++ b/tools/objtool/arch/arm64/include/arch/special.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _ARM64_ARCH_SPECIAL_H
+#define _ARM64_ARCH_SPECIAL_H
+
+#define EX_ENTRY_SIZE 12
+#define EX_ORIG_OFFSET 0
+#define EX_NEW_OFFSET 4
+
+#define JUMP_ENTRY_SIZE 16
+#define JUMP_ORIG_OFFSET 0
+#define JUMP_NEW_OFFSET 4
+#define JUMP_KEY_OFFSET 8
+
+#define ALT_ENTRY_SIZE 12
+#define ALT_ORIG_OFFSET 0
+#define ALT_NEW_OFFSET 4
+#define ALT_FEATURE_OFFSET 8
+#define ALT_ORIG_LEN_OFFSET 10
+#define ALT_NEW_LEN_OFFSET 11
+
+#endif /* _ARM64_ARCH_SPECIAL_H */
diff --git a/tools/objtool/arch/arm64/special.c b/tools/objtool/arch/arm64/special.c
new file mode 100644
index 000000000000..45f283283091
--- /dev/null
+++ b/tools/objtool/arch/arm64/special.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <objtool/special.h>
+
+void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
+{
+}
+
+bool arch_support_alt_relocation(struct special_alt *special_alt,
+ struct instruction *insn,
+ struct reloc *reloc)
+{
+ return false;
+}
+
+
+struct reloc *arch_find_switch_table(struct objtool_file *file,
+ struct instruction *insn)
+{
+ return NULL;
+}
--
2.17.1