//===-- PlatformLinux.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 "PlatformLinux.h"

#include "lldb/Host/Config.h"

#include <cstdio>

#if LLDB_ENABLE_POSIX

#include <sys/utsname.h>

#endif

#include "Utility/ARM64_DWARF_Registers.h"

#include "lldb/Core/Debugger.h"

#include "lldb/Core/PluginManager.h"

#include "lldb/Host/HostInfo.h"

#include "lldb/Symbol/UnwindPlan.h"

#include "lldb/Target/Process.h"

#include "lldb/Target/Target.h"

#include "lldb/Utility/FileSpec.h"

#include "lldb/Utility/LLDBLog.h"

#include "lldb/Utility/Log.h"

#include "lldb/Utility/State.h"

#include "lldb/Utility/Status.h"

#include "lldb/Utility/StreamString.h"

// Define these constants from Linux mman.h for use when targeting remote linux

// systems even when host has different values.

#define MAP_PRIVATE 2

#define MAP_ANON 0x20

using namespace lldb;

using namespace lldb_private;

using namespace lldb_private::platform_linux;

LLDB_PLUGIN_DEFINE(PlatformLinux)

static uint32_t g_initialize_count = 0;

PlatformSP PlatformLinux::CreateInstance(bool force, const ArchSpec *arch) {

  Log *log = GetLog(LLDBLog::Platform);

  LLDB_LOG(log, "force = {0}, arch=({1}, {2})", force,

           arch ? arch->GetArchitectureName() : "<null>",

           arch ? arch->GetTriple().getTriple() : "<null>");

  bool create = force;

  if (!create && 
arch339
 && 
arch->IsValid()339
) {

    const llvm::Triple &triple = arch->GetTriple();

    switch (triple.getOS()) {

    case llvm::Triple::Linux:

      create = true;

      break;

#if defined(__linux__)

    // Only accept "unknown" for the OS if the host is linux and it "unknown"

    // wasn't specified (it was just returned because it was NOT specified)

    case llvm::Triple::OSType::UnknownOS:

      create = !arch->TripleOSWasSpecified();

      break;

#endif

    default:

      break;

    }

  }

  LLDB_LOG(log, "create = {0}", create);

  if (create) {

    return PlatformSP(new PlatformLinux(false));

  }

  return PlatformSP();

}

llvm::StringRef PlatformLinux::GetPluginDescriptionStatic(bool is_host) {

  if (is_host)

    return "Local Linux user platform plug-in.";

  return "Remote Linux user platform plug-in.";

}

void PlatformLinux::Initialize() {

  PlatformPOSIX::Initialize();

  if (g_initialize_count++ == 0) {

#if defined(__linux__) && !defined(__ANDROID__)

    PlatformSP default_platform_sp(new PlatformLinux(true));

    default_platform_sp->SetSystemArchitecture(HostInfo::GetArchitecture());

    Platform::SetHostPlatform(default_platform_sp);

#endif

    PluginManager::RegisterPlugin(

        PlatformLinux::GetPluginNameStatic(false),

        PlatformLinux::GetPluginDescriptionStatic(false),

        PlatformLinux::CreateInstance, nullptr);

  }

}

void PlatformLinux::Terminate() {

  if (g_initialize_count > 0) {

    if (--g_initialize_count == 0) {

      PluginManager::UnregisterPlugin(PlatformLinux::CreateInstance);

    }

  }

  PlatformPOSIX::Terminate();

}

/// Default Constructor

PlatformLinux::PlatformLinux(bool is_host)

    : PlatformPOSIX(is_host) // This is the local host platform

{

  if (is_host) {

    ArchSpec hostArch = HostInfo::GetArchitecture(HostInfo::eArchKindDefault);

    m_supported_architectures.push_back(hostArch);

    if (hostArch.GetTriple().isArch64Bit()) {

      m_supported_architectures.push_back(

          HostInfo::GetArchitecture(HostInfo::eArchKind32));

    }

  } else {

    m_supported_architectures = CreateArchList(

        {llvm::Triple::x86_64, llvm::Triple::x86, llvm::Triple::arm,

         llvm::Triple::aarch64, llvm::Triple::mips64, llvm::Triple::mips64,

         llvm::Triple::hexagon, llvm::Triple::mips, llvm::Triple::mips64el,

         llvm::Triple::mipsel, llvm::Triple::msp430, llvm::Triple::systemz},

        llvm::Triple::Linux);

  }

}

std::vector<ArchSpec>

PlatformLinux::GetSupportedArchitectures(const ArchSpec &process_host_arch) {

  if (m_remote_platform_sp)

    return m_remote_platform_sp->GetSupportedArchitectures(process_host_arch);

  return m_supported_architectures;

}

void PlatformLinux::GetStatus(Stream &strm) {

  Platform::GetStatus(strm);

#if LLDB_ENABLE_POSIX

  // Display local kernel information only when we are running in host mode.

  // Otherwise, we would end up printing non-Linux information (when running on

  // Mac OS for example).

  if (IsHost()) {

    struct utsname un;

    if (uname(&un))

      return;

    strm.Printf("    Kernel: %s\n", un.sysname);

    strm.Printf("   Release: %s\n", un.release);

    strm.Printf("   Version: %s\n", un.version);

  }

#endif

}

uint32_t

PlatformLinux::GetResumeCountForLaunchInfo(ProcessLaunchInfo &launch_info) {

  uint32_t resume_count = 0;

  // Always resume past the initial stop when we use eLaunchFlagDebug

  if (launch_info.GetFlags().Test(eLaunchFlagDebug)) {

    // Resume past the stop for the final exec into the true inferior.

    ++resume_count;

  }

  // If we're not launching a shell, we're done.

  const FileSpec &shell = launch_info.GetShell();

  if (!shell)

    return resume_count;

  std::string shell_string = shell.GetPath();

  // We're in a shell, so for sure we have to resume past the shell exec.

  ++resume_count;

  // Figure out what shell we're planning on using.

  const char *shell_name = strrchr(shell_string.c_str(), '/');

  if (shell_name == nullptr)

    shell_name = shell_string.c_str();

  else

    shell_name++;

  if (strcmp(shell_name, "csh") == 0 || strcmp(shell_name, "tcsh") == 0 ||

      strcmp(shell_name, "zsh") == 0 || strcmp(shell_name, "sh") == 0) {

    // These shells seem to re-exec themselves.  Add another resume.

    ++resume_count;

  }

  return resume_count;

}

bool PlatformLinux::CanDebugProcess() {

  if (IsHost()) {

    return true;

  } else {

    // If we're connected, we can debug.

    return IsConnected();

  }

}

void PlatformLinux::CalculateTrapHandlerSymbolNames() {

  m_trap_handlers.push_back(ConstString("_sigtramp"));

  m_trap_handlers.push_back(ConstString("__kernel_rt_sigreturn"));

  m_trap_handlers.push_back(ConstString("__restore_rt"));

}

static lldb::UnwindPlanSP GetAArch64TrapHanlderUnwindPlan(ConstString name) {

  UnwindPlanSP unwind_plan_sp;

  if (name != "__kernel_rt_sigreturn")

    return unwind_plan_sp;

  UnwindPlan::RowSP row = std::make_shared<UnwindPlan::Row>();

  row->SetOffset(0);

  // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:

  //  - 128-byte siginfo struct

  //  - ucontext struct:

  //     - 8-byte long (uc_flags)

  //     - 8-byte pointer (uc_link)

  //     - 24-byte stack_t

  //     - 128-byte signal set

  //     - 8 bytes of padding because sigcontext has 16-byte alignment

  //     - sigcontext/mcontext_t

  // [1]

  // https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c

  int32_t offset = 128 + 8 + 8 + 24 + 128 + 8;

  // Then sigcontext[2] is:

  // - 8 byte fault address

  // - 31 8 byte registers

  // - 8 byte sp

  // - 8 byte pc

  // [2]

  // https://github.com/torvalds/linux/blob/master/arch/arm64/include/uapi/asm/sigcontext.h

  // Skip fault address

  offset += 8;

  row->GetCFAValue().SetIsRegisterPlusOffset(arm64_dwarf::sp, offset);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x0, 0 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x1, 1 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x2, 2 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x3, 3 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x4, 4 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x5, 5 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x6, 6 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x7, 7 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x8, 8 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x9, 9 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x10, 10 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x11, 11 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x12, 12 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x13, 13 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x14, 14 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x15, 15 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x16, 16 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x17, 17 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x18, 18 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x19, 19 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x20, 20 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x21, 21 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x22, 22 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x23, 23 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x24, 24 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x25, 25 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x26, 26 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x27, 27 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x28, 28 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::fp, 29 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x30, 30 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::sp, 31 * 8, false);

  row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::pc, 32 * 8, false);

  // The sigcontext may also contain floating point and SVE registers.

  // However this would require a dynamic unwind plan so they are not included

  // here.

  unwind_plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);

  unwind_plan_sp->AppendRow(row);

  unwind_plan_sp->SetSourceName("AArch64 Linux sigcontext");

  unwind_plan_sp->SetSourcedFromCompiler(eLazyBoolYes);

  // Because sp is the same throughout the function

  unwind_plan_sp->SetUnwindPlanValidAtAllInstructions(eLazyBoolYes);

  unwind_plan_sp->SetUnwindPlanForSignalTrap(eLazyBoolYes);

  return unwind_plan_sp;

}

lldb::UnwindPlanSP

PlatformLinux::GetTrapHandlerUnwindPlan(const llvm::Triple &triple,

                                        ConstString name) {

  if (triple.isAArch64())

    return GetAArch64TrapHanlderUnwindPlan(name);

  return {};

}

MmapArgList PlatformLinux::GetMmapArgumentList(const ArchSpec &arch,

                                               addr_t addr, addr_t length,

                                               unsigned prot, unsigned flags,

                                               addr_t fd, addr_t offset) {

  uint64_t flags_platform = 0;

  uint64_t map_anon = arch.IsMIPS() ? 0x800 : MAP_ANON;

  if (flags & eMmapFlagsPrivate)

    flags_platform |= MAP_PRIVATE;

  if (flags & eMmapFlagsAnon)

    flags_platform |= map_anon;

  MmapArgList args({addr, length, prot, flags_platform, fd, offset});

  return args;

}

CompilerType PlatformLinux::GetSiginfoType(const llvm::Triple &triple) {

  {

    std::lock_guard<std::mutex> guard(m_mutex);

    if (!m_type_system)

      m_type_system = std::make_shared<TypeSystemClang>("siginfo", triple);

  }

  TypeSystemClang *ast = m_type_system.get();

  bool si_errno_then_code = true;

  switch (triple.getArch()) {

  case llvm::Triple::mips:

  case llvm::Triple::mipsel:

  case llvm::Triple::mips64:

  case llvm::Triple::mips64el:

    // mips has si_code and si_errno swapped

    si_errno_then_code = false;

    break;

  default:

    break;

  }

  // generic types

  CompilerType int_type = ast->GetBasicType(eBasicTypeInt);

  CompilerType uint_type = ast->GetBasicType(eBasicTypeUnsignedInt);

  CompilerType short_type = ast->GetBasicType(eBasicTypeShort);

  CompilerType long_type = ast->GetBasicType(eBasicTypeLong);

  CompilerType voidp_type = ast->GetBasicType(eBasicTypeVoid).GetPointerType();

  // platform-specific types

  CompilerType &pid_type = int_type;

  CompilerType &uid_type = uint_type;

  CompilerType &clock_type = long_type;

  CompilerType &band_type = long_type;

  CompilerType sigval_type = ast->CreateRecordType(

      nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "__lldb_sigval_t",

      clang::TTK_Union, lldb::eLanguageTypeC);

  ast->StartTagDeclarationDefinition(sigval_type);

  ast->AddFieldToRecordType(sigval_type, "sival_int", int_type,

                            lldb::eAccessPublic, 0);

  ast->AddFieldToRecordType(sigval_type, "sival_ptr", voidp_type,

                            lldb::eAccessPublic, 0);

  ast->CompleteTagDeclarationDefinition(sigval_type);

  CompilerType sigfault_bounds_type = ast->CreateRecordType(

      nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "",

      clang::TTK_Union, lldb::eLanguageTypeC);

  ast->StartTagDeclarationDefinition(sigfault_bounds_type);

  ast->AddFieldToRecordType(

      sigfault_bounds_type, "_addr_bnd",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"_lower", voidp_type},

                                         {"_upper", voidp_type},

                                     }),

      lldb::eAccessPublic, 0);

  ast->AddFieldToRecordType(sigfault_bounds_type, "_pkey", uint_type,

                            lldb::eAccessPublic, 0);

  ast->CompleteTagDeclarationDefinition(sigfault_bounds_type);

  // siginfo_t

  CompilerType siginfo_type = ast->CreateRecordType(

      nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "__lldb_siginfo_t",

      clang::TTK_Struct, lldb::eLanguageTypeC);

  ast->StartTagDeclarationDefinition(siginfo_type);

  ast->AddFieldToRecordType(siginfo_type, "si_signo", int_type,

                            lldb::eAccessPublic, 0);

  if (si_errno_then_code) {

    ast->AddFieldToRecordType(siginfo_type, "si_errno", int_type,

                              lldb::eAccessPublic, 0);

    ast->AddFieldToRecordType(siginfo_type, "si_code", int_type,

                              lldb::eAccessPublic, 0);

  } else {

    ast->AddFieldToRecordType(siginfo_type, "si_code", int_type,

                              lldb::eAccessPublic, 0);

    ast->AddFieldToRecordType(siginfo_type, "si_errno", int_type,

                              lldb::eAccessPublic, 0);

  }

  // the structure is padded on 64-bit arches to fix alignment

  if (triple.isArch64Bit())

    ast->AddFieldToRecordType(siginfo_type, "__pad0", int_type,

                              lldb::eAccessPublic, 0);

  // union used to hold the signal data

  CompilerType union_type = ast->CreateRecordType(

      nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "",

      clang::TTK_Union, lldb::eLanguageTypeC);

  ast->StartTagDeclarationDefinition(union_type);

  ast->AddFieldToRecordType(

      union_type, "_kill",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"si_pid", pid_type},

                                         {"si_uid", uid_type},

                                     }),

      lldb::eAccessPublic, 0);

  ast->AddFieldToRecordType(

      union_type, "_timer",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"si_tid", int_type},

                                         {"si_overrun", int_type},

                                         {"si_sigval", sigval_type},

                                     }),

      lldb::eAccessPublic, 0);

  ast->AddFieldToRecordType(

      union_type, "_rt",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"si_pid", pid_type},

                                         {"si_uid", uid_type},

                                         {"si_sigval", sigval_type},

                                     }),

      lldb::eAccessPublic, 0);

  ast->AddFieldToRecordType(

      union_type, "_sigchld",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"si_pid", pid_type},

                                         {"si_uid", uid_type},

                                         {"si_status", int_type},

                                         {"si_utime", clock_type},

                                         {"si_stime", clock_type},

                                     }),

      lldb::eAccessPublic, 0);

  ast->AddFieldToRecordType(

      union_type, "_sigfault",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"si_addr", voidp_type},

                                         {"si_addr_lsb", short_type},

                                         {"_bounds", sigfault_bounds_type},

                                     }),

      lldb::eAccessPublic, 0);

  ast->AddFieldToRecordType(

      union_type, "_sigpoll",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"si_band", band_type},

                                         {"si_fd", int_type},

                                     }),

      lldb::eAccessPublic, 0);

  // NB: SIGSYS is not present on ia64 but we don't seem to support that

  ast->AddFieldToRecordType(

      union_type, "_sigsys",

      ast->CreateStructForIdentifier(llvm::StringRef(),

                                     {

                                         {"_call_addr", voidp_type},

                                         {"_syscall", int_type},

                                         {"_arch", uint_type},

                                     }),

      lldb::eAccessPublic, 0);

  ast->CompleteTagDeclarationDefinition(union_type);

  ast->AddFieldToRecordType(siginfo_type, "_sifields", union_type,

                            lldb::eAccessPublic, 0);

  ast->CompleteTagDeclarationDefinition(siginfo_type);

  return siginfo_type;

}