objtool/LoongArch: Enable objtool to be built

Add the minimal changes to enable objtool build on LoongArch,
most of the functions are stubs to only fix the build errors
when make -C tools/objtool.

This is similar with commit e52ec98c5ab1 ("objtool/powerpc:
Enable objtool to be built on ppc").

Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/tools/objtool/arch/loongarch/Build b/tools/objtool/arch/loongarch/Build
new file mode 100644 (file)
index 0000000..d24d563
--- /dev/null
+++ b/tools/objtool/arch/loongarch/Build
@@ -0,0 +1,2 @@
+objtool-y += decode.o
+objtool-y += special.o

diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c
new file mode 100644 (file)
index 0000000..cc74ba4
--- /dev/null
+++ b/tools/objtool/arch/loongarch/decode.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <string.h>
+#include <objtool/check.h>
+
+int arch_ftrace_match(char *name)
+{
+       return !strcmp(name, "_mcount");
+}
+
+unsigned long arch_jump_destination(struct instruction *insn)
+{
+       return insn->offset + (insn->immediate << 2);
+}
+
+unsigned long arch_dest_reloc_offset(int addend)
+{
+       return addend;
+}
+
+bool arch_pc_relative_reloc(struct reloc *reloc)
+{
+       return false;
+}
+
+bool arch_callee_saved_reg(unsigned char reg)
+{
+       switch (reg) {
+       case CFI_RA:
+       case CFI_FP:
+       case CFI_S0 ... CFI_S8:
+               return true;
+       default:
+               return false;
+       }
+}
+
+int arch_decode_hint_reg(u8 sp_reg, int *base)
+{
+       return 0;
+}
+
+int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
+                           unsigned long offset, unsigned int maxlen,
+                           struct instruction *insn)
+{
+       return 0;
+}
+
+const char *arch_nop_insn(int len)
+{
+       return NULL;
+}
+
+const char *arch_ret_insn(int len)
+{
+       return NULL;
+}
+
+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;
+}

diff --git a/tools/objtool/arch/loongarch/include/arch/cfi_regs.h b/tools/objtool/arch/loongarch/include/arch/cfi_regs.h
new file mode 100644 (file)
index 0000000..d183cc8
--- /dev/null
+++ b/tools/objtool/arch/loongarch/include/arch/cfi_regs.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _OBJTOOL_ARCH_CFI_REGS_H
+#define _OBJTOOL_ARCH_CFI_REGS_H
+
+#define CFI_RA         1
+#define CFI_SP         3
+#define CFI_A0         4
+#define CFI_FP         22
+#define CFI_S0         23
+#define CFI_S1         24
+#define CFI_S2         25
+#define CFI_S3         26
+#define CFI_S4         27
+#define CFI_S5         28
+#define CFI_S6         29
+#define CFI_S7         30
+#define CFI_S8         31
+#define CFI_NUM_REGS   32
+
+#define CFI_BP         CFI_FP
+
+#endif /* _OBJTOOL_ARCH_CFI_REGS_H */

diff --git a/tools/objtool/arch/loongarch/include/arch/elf.h b/tools/objtool/arch/loongarch/include/arch/elf.h
new file mode 100644 (file)
index 0000000..9623d66
--- /dev/null
+++ b/tools/objtool/arch/loongarch/include/arch/elf.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _OBJTOOL_ARCH_ELF_H
+#define _OBJTOOL_ARCH_ELF_H
+
+/*
+ * See the following link for more info about ELF Relocation types:
+ * https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html#_relocations
+ */
+#ifndef R_LARCH_NONE
+#define R_LARCH_NONE           0
+#endif
+#ifndef R_LARCH_32
+#define R_LARCH_32             1
+#endif
+#ifndef R_LARCH_64
+#define R_LARCH_64             2
+#endif
+#ifndef R_LARCH_32_PCREL
+#define R_LARCH_32_PCREL       99
+#endif
+
+#define R_NONE                 R_LARCH_NONE
+#define R_ABS32                        R_LARCH_32
+#define R_ABS64                        R_LARCH_64
+#define R_DATA32               R_LARCH_32_PCREL
+#define R_DATA64               R_LARCH_32_PCREL
+#define R_TEXT32               R_LARCH_32_PCREL
+#define R_TEXT64               R_LARCH_32_PCREL
+
+#endif /* _OBJTOOL_ARCH_ELF_H */

diff --git a/tools/objtool/arch/loongarch/include/arch/special.h b/tools/objtool/arch/loongarch/include/arch/special.h
new file mode 100644 (file)
index 0000000..35fc979
--- /dev/null
+++ b/tools/objtool/arch/loongarch/include/arch/special.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _OBJTOOL_ARCH_SPECIAL_H
+#define _OBJTOOL_ARCH_SPECIAL_H
+
+/*
+ * See more info about struct exception_table_entry
+ * in arch/loongarch/include/asm/extable.h
+ */
+#define EX_ENTRY_SIZE          12
+#define EX_ORIG_OFFSET         0
+#define EX_NEW_OFFSET          4
+
+/*
+ * See more info about struct jump_entry
+ * in include/linux/jump_label.h
+ */
+#define JUMP_ENTRY_SIZE                16
+#define JUMP_ORIG_OFFSET       0
+#define JUMP_NEW_OFFSET                4
+#define JUMP_KEY_OFFSET                8
+
+/*
+ * See more info about struct alt_instr
+ * in arch/loongarch/include/asm/alternative.h
+ */
+#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 /* _OBJTOOL_ARCH_SPECIAL_H */

diff --git a/tools/objtool/arch/loongarch/special.c b/tools/objtool/arch/loongarch/special.c
new file mode 100644 (file)
index 0000000..9bba1e9
--- /dev/null
+++ b/tools/objtool/arch/loongarch/special.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <objtool/special.h>
+
+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;
+}