root/arch/um/os-Linux/registers.c

DEFINITIONS

1. save_registers
2. restore_registers
3. init_registers
4. get_safe_registers

   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 
  14 int 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 
  24 int 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 
  36 static unsigned long exec_regs[MAX_REG_NR];
  37 static unsigned long exec_fp_regs[FP_SIZE];
  38 
  39 int 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 
  52 void 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 }