// SPDX-License-Identifier: GPL-2.0
/*
 * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
 *
 * Written by: Masami Hiramatsu <mhiramat@kernel.org>
 */

#include <stdlib.h>
#include <string.h>
#include <debug.h>
#include <dwarf-regs.h>
#include <elf.h>
#include <errno.h>
#include <linux/kernel.h>

/* Define const char * {arch}_register_tbl[] */
#define DEFINE_DWARF_REGSTR_TABLE
#include "../arch/x86/include/dwarf-regs-table.h"
#include "../arch/arm/include/dwarf-regs-table.h"
#include "../arch/arm64/include/dwarf-regs-table.h"
#include "../arch/sh/include/dwarf-regs-table.h"
#include "../arch/powerpc/include/dwarf-regs-table.h"
#include "../arch/riscv/include/dwarf-regs-table.h"
#include "../arch/s390/include/dwarf-regs-table.h"
#include "../arch/sparc/include/dwarf-regs-table.h"
#include "../arch/xtensa/include/dwarf-regs-table.h"
#include "../arch/mips/include/dwarf-regs-table.h"
#include "../arch/loongarch/include/dwarf-regs-table.h"

/* Return architecture dependent register string (for kprobe-tracer) */
const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int flags)
{
        #define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)

        if (machine == EM_NONE) {
                /* Generic arch - use host arch */
                machine = EM_HOST;
        }
        switch (machine) {
        case EM_386:
                return __get_dwarf_regstr(x86_32_regstr_tbl, n);
        case EM_X86_64:
                return __get_dwarf_regstr(x86_64_regstr_tbl, n);
        case EM_ARM:
                return __get_dwarf_regstr(arm_regstr_tbl, n);
        case EM_AARCH64:
                return __get_dwarf_regstr(aarch64_regstr_tbl, n);
        case EM_CSKY:
                return __get_csky_regstr(n, flags);
        case EM_SH:
                return __get_dwarf_regstr(sh_regstr_tbl, n);
        case EM_S390:
                return __get_dwarf_regstr(s390_regstr_tbl, n);
        case EM_PPC:
        case EM_PPC64:
                return __get_dwarf_regstr(powerpc_regstr_tbl, n);
        case EM_RISCV:
                return __get_dwarf_regstr(riscv_regstr_tbl, n);
        case EM_SPARC:
        case EM_SPARCV9:
                return __get_dwarf_regstr(sparc_regstr_tbl, n);
        case EM_XTENSA:
                return __get_dwarf_regstr(xtensa_regstr_tbl, n);
        case EM_MIPS:
                return __get_dwarf_regstr(mips_regstr_tbl, n);
        case EM_LOONGARCH:
                return __get_dwarf_regstr(loongarch_regstr_tbl, n);
        default:
                pr_err("ELF MACHINE %x is not supported.\n", machine);
        }
        return NULL;

        #undef __get_dwarf_regstr
}

static int __get_dwarf_regnum(const char *const *regstr, size_t num_regstr, const char *name)
{
        for (size_t i = 0; i < num_regstr; i++) {
                if (regstr[i] && !strcmp(regstr[i], name))
                        return i;
        }
        return -ENOENT;
}

/* Return DWARF register number from architecture register name */
int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags)
{
        char *regname = strdup(name);
        int reg = -1;
        char *p;

        #define _get_dwarf_regnum(tbl, name) __get_dwarf_regnum(tbl, ARRAY_SIZE(tbl), name)

        if (regname == NULL)
                return -EINVAL;

        /* For convenience, remove trailing characters */
        p = strpbrk(regname, " ,)");
        if (p)
                *p = '\0';

        if (machine == EM_NONE) {
                /* Generic arch - use host arch */
                machine = EM_HOST;
        }
        switch (machine) {
        case EM_X86_64:
                reg = __get_dwarf_regnum_x86_64(name);
                break;
        case EM_386:
                reg = __get_dwarf_regnum_i386(name);
                break;
        case EM_ARM:
                reg = _get_dwarf_regnum(arm_regstr_tbl, name);
                break;
        case EM_AARCH64:
                reg = _get_dwarf_regnum(aarch64_regstr_tbl, name);
                break;
        case EM_CSKY:
                reg = __get_csky_regnum(name, flags);
                break;
        case EM_SH:
                reg = _get_dwarf_regnum(sh_regstr_tbl, name);
                break;
        case EM_S390:
                reg = _get_dwarf_regnum(s390_regstr_tbl, name);
                break;
        case EM_PPC:
        case EM_PPC64:
                reg = _get_dwarf_regnum(powerpc_regstr_tbl, name);
                break;
        case EM_RISCV:
                reg = _get_dwarf_regnum(riscv_regstr_tbl, name);
                break;
        case EM_SPARC:
        case EM_SPARCV9:
                reg = _get_dwarf_regnum(sparc_regstr_tbl, name);
                break;
        case EM_XTENSA:
                reg = _get_dwarf_regnum(xtensa_regstr_tbl, name);
                break;
        case EM_MIPS:
                reg = _get_dwarf_regnum(mips_regstr_tbl, name);
                break;
        case EM_LOONGARCH:
                reg = _get_dwarf_regnum(loongarch_regstr_tbl, name);
                break;
        default:
                pr_err("ELF MACHINE %x is not supported.\n", machine);
        }
        free(regname);
        return reg;

        #undef _get_dwarf_regnum
}

static int get_libdw_frame_nregs(unsigned int machine, unsigned int flags __maybe_unused)
{
        switch (machine) {
        case EM_X86_64:
                return 17;
        case EM_386:
                return 9;
        case EM_ARM:
                return 16;
        case EM_AARCH64:
                return 97;
        case EM_CSKY:
                return 38;
        case EM_S390:
                return 32;
        case EM_PPC:
        case EM_PPC64:
                return 145;
        case EM_RISCV:
                return 66;
        case EM_SPARC:
        case EM_SPARCV9:
                return 103;
        case EM_LOONGARCH:
                return 74;
        case EM_MIPS:
                return 71;
        default:
                return 0;
        }
}

int get_dwarf_regnum_for_perf_regnum(int perf_regnum, unsigned int machine,
                                     unsigned int flags, bool only_libdw_supported)
{
        int reg;

        switch (machine) {
        case EM_X86_64:
                reg = __get_dwarf_regnum_for_perf_regnum_x86_64(perf_regnum);
                break;
        case EM_386:
                reg = __get_dwarf_regnum_for_perf_regnum_i386(perf_regnum);
                break;
        case EM_ARM:
                reg = __get_dwarf_regnum_for_perf_regnum_arm(perf_regnum);
                break;
        case EM_AARCH64:
                reg = __get_dwarf_regnum_for_perf_regnum_arm64(perf_regnum);
                break;
        case EM_CSKY:
                reg = __get_dwarf_regnum_for_perf_regnum_csky(perf_regnum, flags);
                break;
        case EM_PPC:
        case EM_PPC64:
                reg = __get_dwarf_regnum_for_perf_regnum_powerpc(perf_regnum);
                break;
        case EM_RISCV:
                reg = __get_dwarf_regnum_for_perf_regnum_riscv(perf_regnum);
                break;
        case EM_S390:
                reg = __get_dwarf_regnum_for_perf_regnum_s390(perf_regnum);
                break;
        case EM_LOONGARCH:
                reg = __get_dwarf_regnum_for_perf_regnum_loongarch(perf_regnum);
                break;
        case EM_MIPS:
                reg = __get_dwarf_regnum_for_perf_regnum_mips(perf_regnum);
                break;
        default:
                pr_err("ELF MACHINE %x is not supported.\n", machine);
                return -ENOENT;
        }
        if (reg >= 0 && only_libdw_supported) {
                int nregs = get_libdw_frame_nregs(machine, flags);

                if (reg >= nregs)
                        reg = -ENOENT;
        }
        return reg;
}