// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/objtool_types.h>
#include <asm/orc_types.h>

#include <objtool/check.h>
#include <objtool/orc.h>
#include <objtool/warn.h>

int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn)
{
        struct cfi_reg *fp = &cfi->regs[CFI_FP];
        struct cfi_reg *ra = &cfi->regs[CFI_RA];

        memset(orc, 0, sizeof(*orc));

        if (!cfi) {
                /*
                 * This is usually either unreachable nops/traps (which don't
                 * trigger unreachable instruction warnings), or
                 * STACK_FRAME_NON_STANDARD functions.
                 */
                orc->type = ORC_TYPE_UNDEFINED;
                return 0;
        }

        switch (cfi->type) {
        case UNWIND_HINT_TYPE_UNDEFINED:
                orc->type = ORC_TYPE_UNDEFINED;
                return 0;
        case UNWIND_HINT_TYPE_END_OF_STACK:
                orc->type = ORC_TYPE_END_OF_STACK;
                return 0;
        case UNWIND_HINT_TYPE_CALL:
                orc->type = ORC_TYPE_CALL;
                break;
        case UNWIND_HINT_TYPE_REGS:
                orc->type = ORC_TYPE_REGS;
                break;
        case UNWIND_HINT_TYPE_REGS_PARTIAL:
                orc->type = ORC_TYPE_REGS_PARTIAL;
                break;
        default:
                ERROR_INSN(insn, "unknown unwind hint type %d", cfi->type);
                return -1;
        }

        orc->signal = cfi->signal;

        switch (cfi->cfa.base) {
        case CFI_SP:
                orc->sp_reg = ORC_REG_SP;
                break;
        case CFI_FP:
                orc->sp_reg = ORC_REG_FP;
                break;
        default:
                ERROR_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
                return -1;
        }

        switch (fp->base) {
        case CFI_UNDEFINED:
                orc->fp_reg = ORC_REG_UNDEFINED;
                orc->fp_offset = 0;
                break;
        case CFI_CFA:
                orc->fp_reg = ORC_REG_PREV_SP;
                orc->fp_offset = fp->offset;
                break;
        case CFI_FP:
                orc->fp_reg = ORC_REG_FP;
                break;
        default:
                ERROR_INSN(insn, "unknown FP base reg %d", fp->base);
                return -1;
        }

        switch (ra->base) {
        case CFI_UNDEFINED:
                orc->ra_reg = ORC_REG_UNDEFINED;
                orc->ra_offset = 0;
                break;
        case CFI_CFA:
                orc->ra_reg = ORC_REG_PREV_SP;
                orc->ra_offset = ra->offset;
                break;
        case CFI_FP:
                orc->ra_reg = ORC_REG_FP;
                break;
        default:
                ERROR_INSN(insn, "unknown RA base reg %d", ra->base);
                return -1;
        }

        orc->sp_offset = cfi->cfa.offset;

        return 0;
}

int write_orc_entry(struct elf *elf, struct section *orc_sec,
                    struct section *ip_sec, unsigned int idx,
                    struct section *insn_sec, unsigned long insn_off,
                    struct orc_entry *o)
{
        struct orc_entry *orc;

        /* populate ORC data */
        orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
        memcpy(orc, o, sizeof(*orc));

        /* populate reloc for ip */
        if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx,
                                     insn_sec, insn_off))
                return -1;

        return 0;
}

static const char *reg_name(unsigned int reg)
{
        switch (reg) {
        case ORC_REG_SP:
                return "sp";
        case ORC_REG_FP:
                return "fp";
        case ORC_REG_PREV_SP:
                return "prevsp";
        default:
                return "?";
        }
}

static const char *orc_type_name(unsigned int type)
{
        switch (type) {
        case UNWIND_HINT_TYPE_CALL:
                return "call";
        case UNWIND_HINT_TYPE_REGS:
                return "regs";
        case UNWIND_HINT_TYPE_REGS_PARTIAL:
                return "regs (partial)";
        default:
                return "?";
        }
}

static void print_reg(unsigned int reg, int offset)
{
        if (reg == ORC_REG_UNDEFINED)
                printf(" (und) ");
        else
                printf("%s + %3d", reg_name(reg), offset);

}

void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i)
{
        printf("type:%s", orc_type_name(orc[i].type));

        printf(" sp:");
        print_reg(orc[i].sp_reg, orc[i].sp_offset);

        printf(" fp:");
        print_reg(orc[i].fp_reg, orc[i].fp_offset);

        printf(" ra:");
        print_reg(orc[i].ra_reg, orc[i].ra_offset);

        printf(" signal:%d\n", orc[i].signal);
}