tools/objtool/arch/powerpc/decode.c

Source file repositories/reference/linux-study-clean/tools/objtool/arch/powerpc/decode.c

File Facts

System
Linux kernel
Corpus path
tools/objtool/arch/powerpc/decode.c
Extension
.c
Size
2934 bytes
Lines
154
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later

#include <stdio.h>
#include <stdlib.h>
#include <objtool/check.h>
#include <objtool/disas.h>
#include <objtool/elf.h>
#include <objtool/arch.h>
#include <objtool/warn.h>
#include <objtool/builtin.h>

const char *arch_reg_name[CFI_NUM_REGS] = {
	"r0",  "sp",  "r2",  "r3",
	"r4",  "r5",  "r6",  "r7",
	"r8",  "r9",  "r10", "r11",
	"r12", "r13", "r14", "r15",
	"r16", "r17", "r18", "r19",
	"r20", "r21", "r22", "r23",
	"r24", "r25", "r26", "r27",
	"r28", "r29", "r30", "r31",
	"ra"
};

int arch_ftrace_match(const char *name)
{
	return !strcmp(name, "_mcount");
}

s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc)
{
	return reloc_addend(reloc);
}

bool arch_callee_saved_reg(unsigned char reg)
{
	return false;
}

int arch_decode_hint_reg(u8 sp_reg, int *base)
{
	exit(-1);
}

const char *arch_nop_insn(int len)
{
	exit(-1);
}

const char *arch_ret_insn(int len)
{
	exit(-1);
}

int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
			    unsigned long offset, unsigned int maxlen,
			    struct instruction *insn)
{
	unsigned int opcode;
	enum insn_type typ;
	unsigned long imm;
	u32 ins;

	ins = bswap_if_needed(file->elf, *(u32 *)(sec->data->d_buf + offset));
	opcode = ins >> 26;
	typ = INSN_OTHER;
	imm = 0;

	switch (opcode) {
	case 18: /* b[l][a] */
		if (ins == 0x48000005)	/* bl .+4 */
			typ = INSN_OTHER;
		else if (ins & 1)	/* bl[a] */
			typ = INSN_CALL;
		else		/* b[a] */
			typ = INSN_JUMP_UNCONDITIONAL;

		imm = ins & 0x3fffffc;
		if (imm & 0x2000000)
			imm -= 0x4000000;
		imm |= ins & 2;	/* AA flag */
		break;
	}

	if (opcode == 1)
		insn->len = 8;
	else
		insn->len = 4;

	insn->type = typ;
	insn->immediate = imm;

Annotation

Implementation Notes