registers.c

  1/*
  2 * Copyright (C) 2004 PathScale, Inc
  3 * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  4 * Licensed under the GPL
  5 */
  6
  7#include <errno.h>
  8#include <stdlib.h>
  9#include <sys/ptrace.h>
 10#ifdef __i386__
 11#include <sys/user.h>
 12#endif
 13#include <longjmp.h>
 14#include <sysdep/ptrace_user.h>
 15#include <sys/uio.h>
 16#include <asm/sigcontext.h>
 17#include <linux/elf.h>
 18#include <registers.h>
 19#include <sys/mman.h>
 20
 21static unsigned long ptrace_regset;
 22unsigned long host_fp_size;
 23
 24int get_fp_registers(int pid, unsigned long *regs)
 25{
 26	struct iovec iov = {
 27		.iov_base = regs,
 28		.iov_len = host_fp_size,
 29	};
 30
 31	if (ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov) < 0)
 32		return -errno;
 33	return 0;
 34}
 35
 36int put_fp_registers(int pid, unsigned long *regs)
 37{
 38	struct iovec iov = {
 39		.iov_base = regs,
 40		.iov_len = host_fp_size,
 41	};
 42
 43	if (ptrace(PTRACE_SETREGSET, pid, ptrace_regset, &iov) < 0)
 44		return -errno;
 45	return 0;
 46}
 47
 48int arch_init_registers(int pid)
 49{
 50	struct iovec iov = {
 51		/* Just use plenty of space, it does not cost us anything */
 52		.iov_len = 2 * 1024 * 1024,
 53	};
 54	int ret;
 55
 56	iov.iov_base = mmap(NULL, iov.iov_len, PROT_WRITE | PROT_READ,
 57			    MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
 58	if (iov.iov_base == MAP_FAILED)
 59		return -ENOMEM;
 60
 61	/* GDB has x86_xsave_length, which uses x86_cpuid_count */
 62	ptrace_regset = NT_X86_XSTATE;
 63	ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
 64	if (ret)
 65		ret = -errno;
 66
 67	if (ret == -ENODEV) {
 68#ifdef CONFIG_X86_32
 69		ptrace_regset = NT_PRXFPREG;
 70#else
 71		ptrace_regset = NT_PRFPREG;
 72#endif
 73		iov.iov_len = 2 * 1024 * 1024;
 74		ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
 75		if (ret)
 76			ret = -errno;
 77	}
 78
 79	munmap(iov.iov_base, 2 * 1024 * 1024);
 80
 81	host_fp_size = iov.iov_len;
 82
 83	return ret;
 84}
 85
 86unsigned long get_thread_reg(int reg, jmp_buf *buf)
 87{
 88	switch (reg) {
 89#ifdef __i386__
 90	case HOST_IP:
 91		return buf[0]->__eip;
 92	case HOST_SP:
 93		return buf[0]->__esp;
 94	case HOST_BP:
 95		return buf[0]->__ebp;
 96#else
 97	case HOST_IP:
 98		return buf[0]->__rip;
 99	case HOST_SP:
100		return buf[0]->__rsp;
101	case HOST_BP:
102		return buf[0]->__rbp;
103#endif
104	default:
105		printk(UM_KERN_ERR "get_thread_regs - unknown register %d\n",
106		       reg);
107		return 0;
108	}
109}