RegisterContextFreeBSDKernelCore_ppc64le.cpp

Go to the documentation of this file.

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "RegisterContextFreeBSDKernelCore_ppc64le.h"
 
#include "lldb/Target/Process.h"
#include "lldb/Target/Thread.h"
#include "lldb/Utility/RegisterValue.h"
#include "llvm/Support/Endian.h"
 
#if defined(__FreeBSD__) && defined(__powerpc64__) && defined(__LITTLE_ENDIAN__)
#include <machine/pcb.h>
#endif
 
using namespace lldb;
using namespace lldb_private;
 
RegisterContextFreeBSDKernelCore_ppc64le::
    RegisterContextFreeBSDKernelCore_ppc64le(
        Thread &thread, lldb_private::RegisterInfoInterface *register_info,
        lldb::addr_t pcb_addr)
    : RegisterContextPOSIX_ppc64le(thread, 0, register_info),
      m_pcb_addr(pcb_addr) {}
 
bool RegisterContextFreeBSDKernelCore_ppc64le::ReadRegister(
    const RegisterInfo *reg_info, RegisterValue &value) {
  if (m_pcb_addr == LLDB_INVALID_ADDRESS)
    return false;
 
  // https://cgit.freebsd.org/src/tree/sys/powerpc/include/pcb.h
  struct {
    llvm::support::ulittle64_t context[20];
    llvm::support::ulittle64_t cr;
    llvm::support::ulittle64_t sp;
    llvm::support::ulittle64_t toc;
    llvm::support::ulittle64_t lr;
  } pcb;
 
#if defined(__FreeBSD__) && defined(__powerpc64__) && defined(__LITTLE_ENDIAN__)
  static_assert(offsetof(struct pcb, pcb_context) ==
                offsetof(decltype(pcb), context));
  static_assert(offsetof(struct pcb, pcb_cr) == offsetof(decltype(pcb), cr));
  static_assert(offsetof(struct pcb, pcb_sp) == offsetof(decltype(pcb), sp));
  static_assert(offsetof(struct pcb, pcb_toc) == offsetof(decltype(pcb), toc));
  static_assert(offsetof(struct pcb, pcb_lr) == offsetof(decltype(pcb), lr));
#endif
 
  Status error;
  size_t rd =
      m_thread.GetProcess()->ReadMemory(m_pcb_addr, &pcb, sizeof(pcb), error);
  if (rd != sizeof(pcb))
    return false;
 
  uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
  switch (reg) {
  case gpr_r1_ppc64le:
    // r1 is saved in the sp field
    value = pcb.sp;
    break;
  case gpr_r2_ppc64le:
    // r2 is saved in the toc field
    value = pcb.toc;
    break;
  case gpr_r12_ppc64le:
  case gpr_r13_ppc64le:
  case gpr_r14_ppc64le:
  case gpr_r15_ppc64le:
  case gpr_r16_ppc64le:
  case gpr_r17_ppc64le:
  case gpr_r18_ppc64le:
  case gpr_r19_ppc64le:
  case gpr_r20_ppc64le:
  case gpr_r21_ppc64le:
  case gpr_r22_ppc64le:
  case gpr_r23_ppc64le:
  case gpr_r24_ppc64le:
  case gpr_r25_ppc64le:
  case gpr_r26_ppc64le:
  case gpr_r27_ppc64le:
  case gpr_r28_ppc64le:
  case gpr_r29_ppc64le:
  case gpr_r30_ppc64le:
  case gpr_r31_ppc64le:
    value = pcb.context[reg - gpr_r12_ppc64le];
    break;
  case gpr_pc_ppc64le:
  case gpr_lr_ppc64le:
    // The pc of crashing thread is stored in lr.
    value = pcb.lr;
    break;
  case gpr_cr_ppc64le:
    value = pcb.cr;
    break;
  default:
    return false;
  }
  return true;
}
 
bool RegisterContextFreeBSDKernelCore_ppc64le::WriteRegister(
    const RegisterInfo *reg_info, const RegisterValue &value) {
  return false;
}