linux/arch/um/os-Linux/registers.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2004 PathScale, Inc
   4 * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   5 */
   6
   7#include <errno.h>
   8#include <string.h>
   9#include <sys/ptrace.h>
  10#include <sysdep/ptrace.h>
  11#include <sysdep/ptrace_user.h>
  12#include <registers.h>
  13
  14int save_registers(int pid, struct uml_pt_regs *regs)
  15{
  16        int err;
  17
  18        err = ptrace(PTRACE_GETREGS, pid, 0, regs->gp);
  19        if (err < 0)
  20                return -errno;
  21        return 0;
  22}
  23
  24int restore_registers(int pid, struct uml_pt_regs *regs)
  25{
  26        int err;
  27
  28        err = ptrace(PTRACE_SETREGS, pid, 0, regs->gp);
  29        if (err < 0)
  30                return -errno;
  31        return 0;
  32}
  33
  34/* This is set once at boot time and not changed thereafter */
  35
  36static unsigned long exec_regs[MAX_REG_NR];
  37static unsigned long exec_fp_regs[FP_SIZE];
  38
  39int init_registers(int pid)
  40{
  41        int err;
  42
  43        err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
  44        if (err < 0)
  45                return -errno;
  46
  47        arch_init_registers(pid);
  48        get_fp_registers(pid, exec_fp_regs);
  49        return 0;
  50}
  51
  52void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
  53{
  54        memcpy(regs, exec_regs, sizeof(exec_regs));
  55
  56        if (fp_regs)
  57                memcpy(fp_regs, exec_fp_regs, sizeof(exec_fp_regs));
  58}
  59