root/arch/sh/kernel/ptrace.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/ptrace.h>

/**
 * regs_query_register_offset() - query register offset from its name
 * @name:       the name of a register
 *
 * regs_query_register_offset() returns the offset of a register in struct
 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
 */
int regs_query_register_offset(const char *name)
{
        const struct pt_regs_offset *roff;
        for (roff = regoffset_table; roff->name != NULL; roff++)
                if (!strcmp(roff->name, name))
                        return roff->offset;
        return -EINVAL;
}

/**
 * regs_query_register_name() - query register name from its offset
 * @offset:     the offset of a register in struct pt_regs.
 *
 * regs_query_register_name() returns the name of a register from its
 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
 */
const char *regs_query_register_name(unsigned int offset)
{
        const struct pt_regs_offset *roff;
        for (roff = regoffset_table; roff->name != NULL; roff++)
                if (roff->offset == offset)
                        return roff->name;
        return NULL;
}