llvm-project/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp

//===-- InferiorCallPOSIX.cpp ---------------------------------------------===//
//
// 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 "InferiorCallPOSIX.h"
#include "lldb/Core/Address.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Expression/DiagnosticManager.h"
#include "lldb/Host/Config.h"
#include "lldb/Symbol/TypeSystem.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Platform.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadPlanCallFunction.h"

#if LLDB_ENABLE_POSIX
#include <sys/mman.h>
#else
// define them
#define PROT_NONE 0
#define PROT_READ 1
#define PROT_WRITE 2
#define PROT_EXEC 4
#endif

using namespace lldb;
using namespace lldb_private;

bool lldb_private::InferiorCallMmap(Process *process, addr_t &allocated_addr,
                                    addr_t addr, addr_t length, unsigned prot,
                                    unsigned flags, addr_t fd, addr_t offset) {
  Thread *thread =
      process->GetThreadList().GetExpressionExecutionThread().get();
  if (thread == nullptr)
    return false;

  const bool include_symbols = true;
  const bool include_inlines = false;
  SymbolContextList sc_list;
  process->GetTarget().GetImages().FindFunctions(
      ConstString("mmap"), eFunctionNameTypeFull, include_symbols,
      include_inlines, sc_list);
  const uint32_t count = sc_list.GetSize();
  if (count > 0) {
    SymbolContext sc;
    if (sc_list.GetContextAtIndex(0, sc)) {
      const uint32_t range_scope =
          eSymbolContextFunction | eSymbolContextSymbol;
      const bool use_inline_block_range = false;
      EvaluateExpressionOptions options;
      options.SetStopOthers(true);
      options.SetUnwindOnError(true);
      options.SetIgnoreBreakpoints(true);
      options.SetTryAllThreads(true);
      options.SetDebug(false);
      options.SetTimeout(process->GetUtilityExpressionTimeout());
      options.SetTrapExceptions(false);

      addr_t prot_arg;
      if (prot == eMmapProtNone)
        prot_arg = PROT_NONE;
      else {
        prot_arg = 0;
        if (prot & eMmapProtExec)
          prot_arg |= PROT_EXEC;
        if (prot & eMmapProtRead)
          prot_arg |= PROT_READ;
        if (prot & eMmapProtWrite)
          prot_arg |= PROT_WRITE;
      }

      AddressRange mmap_range;
      if (sc.GetAddressRange(range_scope, 0, use_inline_block_range,
                             mmap_range)) {
        auto type_system_or_err =
            process->GetTarget().GetScratchTypeSystemForLanguage(
                eLanguageTypeC);
        if (!type_system_or_err) {
          llvm::consumeError(type_system_or_err.takeError());
          return false;
        }
        CompilerType void_ptr_type =
            type_system_or_err->GetBasicTypeFromAST(eBasicTypeVoid)
                .GetPointerType();
        const ArchSpec arch = process->GetTarget().GetArchitecture();
        MmapArgList args =
            process->GetTarget().GetPlatform()->GetMmapArgumentList(
                arch, addr, length, prot_arg, flags, fd, offset);
        lldb::ThreadPlanSP call_plan_sp(
            new ThreadPlanCallFunction(*thread, mmap_range.GetBaseAddress(),
                                       void_ptr_type, args, options));
        if (call_plan_sp) {
          DiagnosticManager diagnostics;

          StackFrame *frame = thread->GetStackFrameAtIndex(0).get();
          if (frame) {
            ExecutionContext exe_ctx;
            frame->CalculateExecutionContext(exe_ctx);
            ExpressionResults result = process->RunThreadPlan(
                exe_ctx, call_plan_sp, options, diagnostics);
            if (result == eExpressionCompleted) {

              allocated_addr =
                  call_plan_sp->GetReturnValueObject()->GetValueAsUnsigned(
                      LLDB_INVALID_ADDRESS);
              if (process->GetAddressByteSize() == 4) {
                if (allocated_addr == UINT32_MAX)
                  return false;
              } else if (process->GetAddressByteSize() == 8) {
                if (allocated_addr == UINT64_MAX)
                  return false;
              }
              return true;
            }
          }
        }
      }
    }
  }

  return false;
}

bool lldb_private::InferiorCallMunmap(Process *process, addr_t addr,
                                      addr_t length) {
  Thread *thread =
      process->GetThreadList().GetExpressionExecutionThread().get();
  if (thread == nullptr)
    return false;

  const bool include_symbols = true;
  const bool include_inlines = false;
  SymbolContextList sc_list;
  process->GetTarget().GetImages().FindFunctions(
      ConstString("munmap"), eFunctionNameTypeFull, include_symbols,
      include_inlines, sc_list);
  const uint32_t count = sc_list.GetSize();
  if (count > 0) {
    SymbolContext sc;
    if (sc_list.GetContextAtIndex(0, sc)) {
      const uint32_t range_scope =
          eSymbolContextFunction | eSymbolContextSymbol;
      const bool use_inline_block_range = false;
      EvaluateExpressionOptions options;
      options.SetStopOthers(true);
      options.SetUnwindOnError(true);
      options.SetIgnoreBreakpoints(true);
      options.SetTryAllThreads(true);
      options.SetDebug(false);
      options.SetTimeout(process->GetUtilityExpressionTimeout());
      options.SetTrapExceptions(false);

      AddressRange munmap_range;
      if (sc.GetAddressRange(range_scope, 0, use_inline_block_range,
                             munmap_range)) {
        lldb::addr_t args[] = {addr, length};
        lldb::ThreadPlanSP call_plan_sp(
            new ThreadPlanCallFunction(*thread, munmap_range.GetBaseAddress(),
                                       CompilerType(), args, options));
        if (call_plan_sp) {
          DiagnosticManager diagnostics;

          StackFrame *frame = thread->GetStackFrameAtIndex(0).get();
          if (frame) {
            ExecutionContext exe_ctx;
            frame->CalculateExecutionContext(exe_ctx);
            ExpressionResults result = process->RunThreadPlan(
                exe_ctx, call_plan_sp, options, diagnostics);
            if (result == eExpressionCompleted) {
              return true;
            }
          }
        }
      }
    }
  }

  return false;
}