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[lldb] Split out NetBSD/x86 watchpoint impl for unification

Browse Source 
Split the current NetBSD watchpoint implementation for x86 into Utility,
and revamp it to improve readability.  This code is meant to be used
as a common class for all x86 watchpoint implementation, particularly
these on FreeBSD and Linux.

The code uses global watchpoint enable bits, as required by the NetBSD
kernel.  If it ever becomes necessary for any platform to use local
enable bits instead, this can be trivially abstracted out.

The code also postpones clearing DR6 until a new different watchpoint
is being set in place of the old one.  This is necessary since LLDB
repeatedly reenables watchpoints on all threads, by clearing
and restoring them.  When DR6 is cleared as a part of that, then pending
events on other threads can no longer be associated with watchpoints
correctly.

Differential Revision: https://reviews.llvm.org/D89874
This commit is contained in:
Michał Górny 2020-10-22 14:18:36 +02:00
parent ab93e71065
commit dae7b10034
9 changed files with 342 additions and 268 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
lldb/include/lldb/Host/common/NativeRegisterContext.h
View File

@ -75,6 +75,8 @@ public:
virtual bool ClearHardwareWatchpoint(uint32_t hw_index);
virtual Status ClearWatchpointHit(uint32_t hw_index);
virtual Status ClearAllHardwareWatchpoints();
virtual Status IsWatchpointHit(uint32_t wp_index, bool &is_hit);

4
lldb/source/Host/common/NativeRegisterContext.cpp
View File

@ -266,6 +266,10 @@ bool NativeRegisterContext::ClearHardwareWatchpoint(uint32_t hw_index) {
return false;
}
Status NativeRegisterContext::ClearWatchpointHit(uint32_t hw_index) {
return Status("not implemented");
}
Status NativeRegisterContext::ClearAllHardwareWatchpoints() {
return Status("not implemented");
}

6
lldb/source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.cpp
View File

@ -20,12 +20,6 @@ using namespace lldb_private::process_netbsd;
#include <sys/ptrace.h>
// clang-format on
NativeRegisterContextNetBSD::NativeRegisterContextNetBSD(
NativeThreadProtocol &native_thread,
RegisterInfoInterface *reg_info_interface_p)
: NativeRegisterContextRegisterInfo(native_thread,
reg_info_interface_p) {}
Status NativeRegisterContextNetBSD::DoRegisterSet(int ptrace_req, void *buf) {
return NativeProcessNetBSD::PtraceWrapper(ptrace_req, GetProcessPid(), buf,
m_thread.GetID());

8
lldb/source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD.h
View File

@ -18,11 +18,9 @@ namespace process_netbsd {
class NativeProcessNetBSD;
class NativeRegisterContextNetBSD : public NativeRegisterContextRegisterInfo {
class NativeRegisterContextNetBSD
: public virtual NativeRegisterContextRegisterInfo {
public:
NativeRegisterContextNetBSD(NativeThreadProtocol &native_thread,
RegisterInfoInterface *reg_info_interface_p);
// This function is implemented in the NativeRegisterContextNetBSD_*
// subclasses to create a new instance of the host specific
// NativeRegisterContextNetBSD. The implementations can't collide as only one
@ -34,8 +32,6 @@ public:
virtual Status
CopyHardwareWatchpointsFrom(NativeRegisterContextNetBSD &source) = 0;
virtual Status ClearWatchpointHit(uint32_t wp_index) = 0;
protected:
Status DoRegisterSet(int req, void *buf);
virtual NativeProcessNetBSD &GetProcess();

233
lldb/source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.cpp
View File

@ -254,8 +254,8 @@ CreateRegisterInfoInterface(const ArchSpec &target_arch) {
NativeRegisterContextNetBSD_x86_64::NativeRegisterContextNetBSD_x86_64(
const ArchSpec &target_arch, NativeThreadProtocol &native_thread)
: NativeRegisterContextNetBSD(native_thread,
CreateRegisterInfoInterface(target_arch)),
: NativeRegisterContextRegisterInfo(
native_thread, CreateRegisterInfoInterface(target_arch)),
m_gpr(), m_fpr(), m_dbr() {}
// CONSIDER after local and llgs debugging are merged, register set support can
@ -1125,235 +1125,6 @@ int NativeRegisterContextNetBSD_x86_64::GetDR(int num) const {
}
}
Status NativeRegisterContextNetBSD_x86_64::IsWatchpointHit(uint32_t wp_index,
bool &is_hit) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
RegisterValue reg_value;
const RegisterInfo *const reg_info = GetRegisterInfoAtIndex(GetDR(6));
Status error = ReadRegister(reg_info, reg_value);
if (error.Fail()) {
is_hit = false;
return error;
}
uint64_t status_bits = reg_value.GetAsUInt64();
is_hit = status_bits & (1 << wp_index);
return error;
}
Status NativeRegisterContextNetBSD_x86_64::GetWatchpointHitIndex(
uint32_t &wp_index, lldb::addr_t trap_addr) {
uint32_t num_hw_wps = NumSupportedHardwareWatchpoints();
for (wp_index = 0; wp_index < num_hw_wps; ++wp_index) {
bool is_hit;
Status error = IsWatchpointHit(wp_index, is_hit);
if (error.Fail()) {
wp_index = LLDB_INVALID_INDEX32;
return error;
} else if (is_hit) {
return error;
}
}
wp_index = LLDB_INVALID_INDEX32;
return Status();
}
Status NativeRegisterContextNetBSD_x86_64::IsWatchpointVacant(uint32_t wp_index,
bool &is_vacant) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
RegisterValue reg_value;
const RegisterInfo *const reg_info = GetRegisterInfoAtIndex(GetDR(7));
Status error = ReadRegister(reg_info, reg_value);
if (error.Fail()) {
is_vacant = false;
return error;
}
uint64_t control_bits = reg_value.GetAsUInt64();
is_vacant = !(control_bits & (1 << (2 * wp_index + 1)));
return error;
}
Status NativeRegisterContextNetBSD_x86_64::SetHardwareWatchpointWithIndex(
lldb::addr_t addr, size_t size, uint32_t watch_flags, uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
// Read only watchpoints aren't supported on x86_64. Fall back to read/write
// waitchpoints instead.
// TODO: Add logic to detect when a write happens and ignore that watchpoint
// hit.
if (watch_flags == 0x2)
watch_flags = 0x3;
if (watch_flags != 0x1 && watch_flags != 0x3)
return Status("Invalid read/write bits for watchpoint");
if (size != 1 && size != 2 && size != 4 && size != 8)
return Status("Invalid size for watchpoint");
bool is_vacant;
Status error = IsWatchpointVacant(wp_index, is_vacant);
if (error.Fail())
return error;
if (!is_vacant)
return Status("Watchpoint index not vacant");
const RegisterInfo *const reg_info_dr7 = GetRegisterInfoAtIndex(GetDR(7));
RegisterValue dr7_value;
error = ReadRegister(reg_info_dr7, dr7_value);
if (error.Fail())
return error;
// for watchpoints 0, 1, 2, or 3, respectively, set bits 1, 3, 5, or 7
uint64_t enable_bit = 1 << (2 * wp_index + 1);
// set bits 16-17, 20-21, 24-25, or 28-29
// with 0b01 for write, and 0b11 for read/write
uint64_t rw_bits = watch_flags << (16 + 4 * wp_index);
// set bits 18-19, 22-23, 26-27, or 30-31
// with 0b00, 0b01, 0b10, or 0b11
// for 1, 2, 8 (if supported), or 4 bytes, respectively
uint64_t size_bits = (size == 8 ? 0x2 : size - 1) << (18 + 4 * wp_index);
uint64_t bit_mask = (0x3 << (2 * wp_index)) | (0xF << (16 + 4 * wp_index));
uint64_t control_bits = dr7_value.GetAsUInt64() & ~bit_mask;
control_bits |= enable_bit | rw_bits | size_bits;
const RegisterInfo *const reg_info_drN =
GetRegisterInfoAtIndex(GetDR(wp_index));
RegisterValue drN_value;
error = ReadRegister(reg_info_drN, drN_value);
if (error.Fail())
return error;
// clear dr6 if address or bits changed (i.e. we're not reenabling the same
// watchpoint)
if (drN_value.GetAsUInt64() != addr ||
(dr7_value.GetAsUInt64() & bit_mask) != (rw_bits | size_bits)) {
ClearWatchpointHit(wp_index);
error = WriteRegister(reg_info_drN, RegisterValue(addr));
if (error.Fail())
return error;
}
error = WriteRegister(reg_info_dr7, RegisterValue(control_bits));
if (error.Fail())
return error;
error.Clear();
return error;
}
bool NativeRegisterContextNetBSD_x86_64::ClearHardwareWatchpoint(
uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return false;
// for watchpoints 0, 1, 2, or 3, respectively, clear bits 0-1, 2-3, 4-5
// or 6-7 of the debug control register (DR7)
const RegisterInfo *const reg_info_dr7 = GetRegisterInfoAtIndex(GetDR(7));
RegisterValue reg_value;
Status error = ReadRegister(reg_info_dr7, reg_value);
if (error.Fail())
return false;
uint64_t bit_mask = 0x3 << (2 * wp_index);
uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
return WriteRegister(reg_info_dr7, RegisterValue(control_bits)).Success();
}
Status NativeRegisterContextNetBSD_x86_64::ClearWatchpointHit(uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
// for watchpoints 0, 1, 2, or 3, respectively, check bits 0, 1, 2, or 3 of
// the debug status register (DR6)
const RegisterInfo *const reg_info_dr6 = GetRegisterInfoAtIndex(GetDR(6));
RegisterValue reg_value;
Status error = ReadRegister(reg_info_dr6, reg_value);
if (error.Fail())
return error;
uint64_t bit_mask = 1 << wp_index;
uint64_t status_bits = reg_value.GetAsUInt64() & ~bit_mask;
return WriteRegister(reg_info_dr6, RegisterValue(status_bits));
}
Status NativeRegisterContextNetBSD_x86_64::ClearAllHardwareWatchpoints() {
RegisterValue reg_value;
// clear bits {0-4} of the debug status register (DR6)
const RegisterInfo *const reg_info_dr6 = GetRegisterInfoAtIndex(GetDR(6));
Status error = ReadRegister(reg_info_dr6, reg_value);
if (error.Fail())
return error;
uint64_t bit_mask = 0xF;
uint64_t status_bits = reg_value.GetAsUInt64() & ~bit_mask;
error = WriteRegister(reg_info_dr6, RegisterValue(status_bits));
if (error.Fail())
return error;
// clear bits {0-7,16-31} of the debug control register (DR7)
const RegisterInfo *const reg_info_dr7 = GetRegisterInfoAtIndex(GetDR(7));
error = ReadRegister(reg_info_dr7, reg_value);
if (error.Fail())
return error;
bit_mask = 0xFF | (0xFFFF << 16);
uint64_t control_bits = reg_value.GetAsUInt64() & ~bit_mask;
return WriteRegister(reg_info_dr7, RegisterValue(control_bits));
}
uint32_t NativeRegisterContextNetBSD_x86_64::SetHardwareWatchpoint(
lldb::addr_t addr, size_t size, uint32_t watch_flags) {
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));
const uint32_t num_hw_watchpoints = NumSupportedHardwareWatchpoints();
for (uint32_t wp_index = 0; wp_index < num_hw_watchpoints; ++wp_index) {
bool is_vacant;
Status error = IsWatchpointVacant(wp_index, is_vacant);
if (is_vacant) {
error = SetHardwareWatchpointWithIndex(addr, size, watch_flags, wp_index);
if (error.Success())
return wp_index;
}
if (error.Fail() && log) {
LLDB_LOGF(log, "NativeRegisterContextNetBSD_x86_64::%s Error: %s",
__FUNCTION__, error.AsCString());
}
}
return LLDB_INVALID_INDEX32;
}
lldb::addr_t
NativeRegisterContextNetBSD_x86_64::GetWatchpointAddress(uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return LLDB_INVALID_ADDRESS;
RegisterValue reg_value;
const RegisterInfo *const reg_info_drN =
GetRegisterInfoAtIndex(GetDR(wp_index));
if (ReadRegister(reg_info_drN, reg_value).Fail())
return LLDB_INVALID_ADDRESS;
return reg_value.GetAsUInt64();
}
uint32_t NativeRegisterContextNetBSD_x86_64::NumSupportedHardwareWatchpoints() {
// Available debug address registers: dr0, dr1, dr2, dr3
return 4;
}
Status NativeRegisterContextNetBSD_x86_64::CopyHardwareWatchpointsFrom(
NativeRegisterContextNetBSD &source) {
auto &r_source = static_cast<NativeRegisterContextNetBSD_x86_64&>(source);

29
lldb/source/Plugins/Process/NetBSD/NativeRegisterContextNetBSD_x86_64.h
View File

@ -20,6 +20,7 @@
#include "Plugins/Process/NetBSD/NativeRegisterContextNetBSD.h"
#include "Plugins/Process/Utility/RegisterContext_x86.h"
#include "Plugins/Process/Utility/NativeRegisterContextWatchpoint_x86.h"
#include "Plugins/Process/Utility/lldb-x86-register-enums.h"
#if defined(PT_GETXSTATE) && defined(PT_SETXSTATE)
@ -31,7 +32,9 @@ namespace process_netbsd {
class NativeProcessNetBSD;
class NativeRegisterContextNetBSD_x86_64 : public NativeRegisterContextNetBSD {
class NativeRegisterContextNetBSD_x86_64
: public NativeRegisterContextNetBSD,
public NativeRegisterContextWatchpoint_x86 {
public:
NativeRegisterContextNetBSD_x86_64(const ArchSpec &target_arch,
NativeThreadProtocol &native_thread);
@ -49,30 +52,6 @@ public:
Status WriteAllRegisterValues(const lldb::DataBufferSP &data_sp) override;
Status IsWatchpointHit(uint32_t wp_index, bool &is_hit) override;
Status GetWatchpointHitIndex(uint32_t &wp_index,
lldb::addr_t trap_addr) override;
Status IsWatchpointVacant(uint32_t wp_index, bool &is_vacant) override;
bool ClearHardwareWatchpoint(uint32_t wp_index) override;
Status ClearWatchpointHit(uint32_t wp_index) override;
Status ClearAllHardwareWatchpoints() override;
Status SetHardwareWatchpointWithIndex(lldb::addr_t addr, size_t size,
uint32_t watch_flags,
uint32_t wp_index);
uint32_t SetHardwareWatchpoint(lldb::addr_t addr, size_t size,
uint32_t watch_flags) override;
lldb::addr_t GetWatchpointAddress(uint32_t wp_index) override;
uint32_t NumSupportedHardwareWatchpoints() override;
Status
CopyHardwareWatchpointsFrom(NativeRegisterContextNetBSD &source) override;

1
lldb/source/Plugins/Process/Utility/CMakeLists.txt
View File

@ -10,6 +10,7 @@ add_lldb_library(lldbPluginProcessUtility
LinuxSignals.cpp
MipsLinuxSignals.cpp
NativeRegisterContextRegisterInfo.cpp
NativeRegisterContextWatchpoint_x86.cpp
NetBSDSignals.cpp
RegisterContextDarwin_arm.cpp
RegisterContextDarwin_arm64.cpp

278
lldb/source/Plugins/Process/Utility/NativeRegisterContextWatchpoint_x86.cpp Normal file
View File

@ -0,0 +1,278 @@
//===-- NativeRegisterContextWatchpoint_x86.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 "NativeRegisterContextWatchpoint_x86.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/RegisterValue.h"
#include "Plugins/Process/Utility/lldb-x86-register-enums.h"
using namespace lldb_private;
// Returns mask/value for status bit of wp_index in DR6
static inline uint64_t GetStatusBit(uint32_t wp_index) {
// DR6: ...BBBB
// 3210 <- status bits for bp./wp. i; 1 if hit
return 1 << wp_index;
}
// Returns mask/value for global enable bit of wp_index in DR7
static inline uint64_t GetEnableBit(uint32_t wp_index) {
// DR7: ...GLGLGLGL
// 33221100 <- global/local enable for bp./wp.; 1 if enabled
// we use global bits because NetBSD kernel does not preserve local
// bits reliably; Linux seems fine with either
return 1 << (2 * wp_index + 1);
}
// Returns mask for both enable bits of wp_index in DR7
static inline uint64_t GetBothEnableBitMask(uint32_t wp_index) {
// DR7: ...GLGLGLGL
// 33221100 <- global/local enable for bp./wp.; 1 if enabled
return 3 << (2 * wp_index + 1);
}
// Returns value for type bits of wp_index in DR7
static inline uint64_t GetWatchTypeBits(uint32_t watch_flags,
uint32_t wp_index) {
// DR7:
// bit: 3322222222221111...
// 1098765432109876...
// val: SSTTSSTTSSTTSSTT...
// wp.: 3333222211110000...
//
// where T - type is 01 for write, 11 for r/w
return watch_flags << (16 + 4 * wp_index);
}
// Returns value for size bits of wp_index in DR7
static inline uint64_t GetWatchSizeBits(uint32_t size, uint32_t wp_index) {
// DR7:
// bit: 3322222222221111...
// 1098765432109876...
// val: SSTTSSTTSSTTSSTT...
// wp.: 3333222211110000...
//
// where S - size is:
// 00 for 1 byte
// 01 for 2 bytes
// 10 for 8 bytes
// 11 for 4 bytes
return (size == 8 ? 0x2 : size - 1) << (18 + 4 * wp_index);
}
// Returns bitmask for all bits controlling wp_index in DR7
static inline uint64_t GetWatchControlBitmask(uint32_t wp_index) {
// DR7:
// bit: 33222222222211111111110000000000
// 10987654321098765432109876543210
// val: SSTTSSTTSSTTSSTTxxxxxxGLGLGLGLGL
// wp.: 3333222211110000xxxxxxEE33221100
return GetBothEnableBitMask(wp_index) | (0xF << (16 + 4 * wp_index));
}
// Bit mask for control bits regarding all watchpoints.
static constexpr uint64_t watchpoint_all_control_bit_mask = 0xFFFF00FF;
const RegisterInfo *NativeRegisterContextWatchpoint_x86::GetDR(int num) const {
assert(num >= 0 && num <= 7);
switch (GetRegisterInfoInterface().GetTargetArchitecture().GetMachine()) {
case llvm::Triple::x86:
return GetRegisterInfoAtIndex(lldb_dr0_i386 + num);
case llvm::Triple::x86_64:
return GetRegisterInfoAtIndex(lldb_dr0_x86_64 + num);
default:
llvm_unreachable("Unhandled target architecture.");
}
}
Status NativeRegisterContextWatchpoint_x86::IsWatchpointHit(uint32_t wp_index,
bool &is_hit) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
RegisterValue dr6;
Status error = ReadRegister(GetDR(6), dr6);
if (error.Fail())
is_hit = false;
else
is_hit = dr6.GetAsUInt64() & GetStatusBit(wp_index);
return error;
}
Status NativeRegisterContextWatchpoint_x86::GetWatchpointHitIndex(
uint32_t &wp_index, lldb::addr_t trap_addr) {
uint32_t num_hw_wps = NumSupportedHardwareWatchpoints();
for (wp_index = 0; wp_index < num_hw_wps; ++wp_index) {
bool is_hit;
Status error = IsWatchpointHit(wp_index, is_hit);
if (error.Fail()) {
wp_index = LLDB_INVALID_INDEX32;
return error;
} else if (is_hit) {
return error;
}
}
wp_index = LLDB_INVALID_INDEX32;
return Status();
}
Status
NativeRegisterContextWatchpoint_x86::IsWatchpointVacant(uint32_t wp_index,
bool &is_vacant) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
RegisterValue dr7;
Status error = ReadRegister(GetDR(7), dr7);
if (error.Fail())
is_vacant = false;
else
is_vacant = !(dr7.GetAsUInt64() & GetEnableBit(wp_index));
return error;
}
Status NativeRegisterContextWatchpoint_x86::SetHardwareWatchpointWithIndex(
lldb::addr_t addr, size_t size, uint32_t watch_flags, uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
// Read only watchpoints aren't supported on x86_64. Fall back to read/write
// waitchpoints instead.
// TODO: Add logic to detect when a write happens and ignore that watchpoint
// hit.
if (watch_flags == 2)
watch_flags = 3;
if (watch_flags != 1 && watch_flags != 3)
return Status("Invalid read/write bits for watchpoint");
if (size != 1 && size != 2 && size != 4 && size != 8)
return Status("Invalid size for watchpoint");
bool is_vacant;
Status error = IsWatchpointVacant(wp_index, is_vacant);
if (error.Fail())
return error;
if (!is_vacant)
return Status("Watchpoint index not vacant");
RegisterValue dr7, drN;
error = ReadRegister(GetDR(7), dr7);
if (error.Fail())
return error;
error = ReadRegister(GetDR(wp_index), drN);
if (error.Fail())
return error;
uint64_t control_bits = dr7.GetAsUInt64() & ~GetWatchControlBitmask(wp_index);
control_bits |= GetEnableBit(wp_index) |
GetWatchTypeBits(watch_flags, wp_index) |
GetWatchSizeBits(size, wp_index);
// Clear dr6 if address or bits changed (i.e. we're not reenabling the same
// watchpoint). This can not be done when clearing watchpoints since
// the gdb-remote protocol repeatedly clears and readds watchpoints on all
// program threads, effectively clearing pending events on NetBSD.
// NB: enable bits in dr7 are always 0 here since we're (re)adding it
if (drN.GetAsUInt64() != addr ||
(dr7.GetAsUInt64() & GetWatchControlBitmask(wp_index)) !=
(GetWatchTypeBits(watch_flags, wp_index) |
GetWatchSizeBits(size, wp_index))) {
ClearWatchpointHit(wp_index);
// We skip update to drN if neither address nor mode changed.
error = WriteRegister(GetDR(wp_index), RegisterValue(addr));
if (error.Fail())
return error;
}
error = WriteRegister(GetDR(7), RegisterValue(control_bits));
if (error.Fail())
return error;
return error;
}
bool NativeRegisterContextWatchpoint_x86::ClearHardwareWatchpoint(
uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return false;
RegisterValue dr7;
Status error = ReadRegister(GetDR(7), dr7);
if (error.Fail())
return false;
return WriteRegister(GetDR(7), RegisterValue(dr7.GetAsUInt64() &
~GetBothEnableBitMask(wp_index)))
.Success();
}
Status
NativeRegisterContextWatchpoint_x86::ClearWatchpointHit(uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return Status("Watchpoint index out of range");
RegisterValue dr6;
Status error = ReadRegister(GetDR(6), dr6);
if (error.Fail())
return error;
return WriteRegister(
GetDR(6), RegisterValue(dr6.GetAsUInt64() & ~GetStatusBit(wp_index)));
}
Status NativeRegisterContextWatchpoint_x86::ClearAllHardwareWatchpoints() {
RegisterValue dr7;
Status error = ReadRegister(GetDR(7), dr7);
if (error.Fail())
return error;
return WriteRegister(
GetDR(7),
RegisterValue(dr7.GetAsUInt64() & ~watchpoint_all_control_bit_mask));
}
uint32_t NativeRegisterContextWatchpoint_x86::SetHardwareWatchpoint(
lldb::addr_t addr, size_t size, uint32_t watch_flags) {
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_WATCHPOINTS));
const uint32_t num_hw_watchpoints = NumSupportedHardwareWatchpoints();
for (uint32_t wp_index = 0; wp_index < num_hw_watchpoints; ++wp_index) {
bool is_vacant;
Status error = IsWatchpointVacant(wp_index, is_vacant);
if (is_vacant) {
error = SetHardwareWatchpointWithIndex(addr, size, watch_flags, wp_index);
if (error.Success())
return wp_index;
}
if (error.Fail() && log) {
LLDB_LOGF(log, "NativeRegisterContextWatchpoint_x86::%s Error: %s",
__FUNCTION__, error.AsCString());
}
}
return LLDB_INVALID_INDEX32;
}
lldb::addr_t
NativeRegisterContextWatchpoint_x86::GetWatchpointAddress(uint32_t wp_index) {
if (wp_index >= NumSupportedHardwareWatchpoints())
return LLDB_INVALID_ADDRESS;
RegisterValue drN;
if (ReadRegister(GetDR(wp_index), drN).Fail())
return LLDB_INVALID_ADDRESS;
return drN.GetAsUInt64();
}
uint32_t
NativeRegisterContextWatchpoint_x86::NumSupportedHardwareWatchpoints() {
// Available debug address registers: dr0, dr1, dr2, dr3
return 4;
}

49
lldb/source/Plugins/Process/Utility/NativeRegisterContextWatchpoint_x86.h Normal file
View File

@ -0,0 +1,49 @@
//===-- NativeRegisterContextWatchpoint_x86.h -------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef lldb_NativeRegisterContextWatchpoint_x86_h
#define lldb_NativeRegisterContextWatchpoint_x86_h
#include "Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h"
namespace lldb_private {
class NativeRegisterContextWatchpoint_x86
: public virtual NativeRegisterContextRegisterInfo {
public:
Status IsWatchpointHit(uint32_t wp_index, bool &is_hit) override;
Status GetWatchpointHitIndex(uint32_t &wp_index,
lldb::addr_t trap_addr) override;
Status IsWatchpointVacant(uint32_t wp_index, bool &is_vacant) override;
bool ClearHardwareWatchpoint(uint32_t wp_index) override;
Status ClearWatchpointHit(uint32_t wp_index) override;
Status ClearAllHardwareWatchpoints() override;
Status SetHardwareWatchpointWithIndex(lldb::addr_t addr, size_t size,
uint32_t watch_flags,
uint32_t wp_index);
uint32_t SetHardwareWatchpoint(lldb::addr_t addr, size_t size,
uint32_t watch_flags) override;
lldb::addr_t GetWatchpointAddress(uint32_t wp_index) override;
uint32_t NumSupportedHardwareWatchpoints() override;
private:
const RegisterInfo *GetDR(int num) const;
};
} // namespace lldb_private
#endif // #ifndef lldb_NativeRegisterContextWatchpoint_x86_h