FreeBSD hardware watchpoint implementation
Implement x86_64 debug register read/write in support of hardware
watchpoints. Hoist LinuxThread::TraceNotify code back into
POSIXThread::TraceNotify()
Patch by John Wolfe.
We still need to rework this later to avoid the #ifdef FreeBSD.
llvm-reviews.chandlerc.com/D2572
llvm.org/pr16706
llvm-svn: 201706
diff --git a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
index 3b26053..3d793d0 100644
--- a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
+++ b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
@@ -101,8 +101,8 @@
log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
}
-#ifdef __amd64__
if (log) {
+#ifdef __amd64__
if (req == PT_GETREGS) {
struct reg *r = (struct reg *) addr;
@@ -111,8 +111,15 @@
log->Printf("PT_GETREGS: bp=0x%lx", r->r_rbp);
log->Printf("PT_GETREGS: ax=0x%lx", r->r_rax);
}
- }
#endif
+ if (req == PT_GETDBREGS || req == PT_SETDBREGS) {
+ struct dbreg *r = (struct dbreg *) addr;
+ char setget = (req == PT_GETDBREGS) ? 'G' : 'S';
+
+ for (int i = 0; i <= 7; i++)
+ log->Printf("PT_%cETDBREGS: dr[%d]=0x%lx", setget, i, r->dr[i]);
+ }
+ }
return result;
}
@@ -348,6 +355,82 @@
}
//------------------------------------------------------------------------------
+/// @class ReadDebugRegOperation
+/// @brief Implements ProcessMonitor::ReadDebugRegisterValue.
+class ReadDebugRegOperation : public Operation
+{
+public:
+ ReadDebugRegOperation(lldb::tid_t tid, unsigned offset, unsigned size,
+ RegisterValue &value, bool &result)
+ : m_tid(tid), m_offset(offset), m_size(size),
+ m_value(value), m_result(result)
+ { }
+
+ void Execute(ProcessMonitor *monitor);
+
+private:
+ lldb::tid_t m_tid;
+ unsigned m_offset;
+ unsigned m_size;
+ RegisterValue &m_value;
+ bool &m_result;
+};
+
+void
+ReadDebugRegOperation::Execute(ProcessMonitor *monitor)
+{
+ struct dbreg regs;
+ int rc;
+
+ if ((rc = PTRACE(PT_GETDBREGS, m_tid, (caddr_t)®s, 0)) < 0) {
+ m_result = false;
+ } else {
+ if (m_size == sizeof(uintptr_t))
+ m_value = *(uintptr_t *)(((caddr_t)®s) + m_offset);
+ else
+ memcpy(&m_value, (((caddr_t)®s) + m_offset), m_size);
+ m_result = true;
+ }
+}
+
+//------------------------------------------------------------------------------
+/// @class WriteDebugRegOperation
+/// @brief Implements ProcessMonitor::WriteDebugRegisterValue.
+class WriteDebugRegOperation : public Operation
+{
+public:
+ WriteDebugRegOperation(lldb::tid_t tid, unsigned offset,
+ const RegisterValue &value, bool &result)
+ : m_tid(tid), m_offset(offset),
+ m_value(value), m_result(result)
+ { }
+
+ void Execute(ProcessMonitor *monitor);
+
+private:
+ lldb::tid_t m_tid;
+ unsigned m_offset;
+ const RegisterValue &m_value;
+ bool &m_result;
+};
+
+void
+WriteDebugRegOperation::Execute(ProcessMonitor *monitor)
+{
+ struct dbreg regs;
+
+ if (PTRACE(PT_GETDBREGS, m_tid, (caddr_t)®s, 0) < 0) {
+ m_result = false;
+ return;
+ }
+ *(uintptr_t *)(((caddr_t)®s) + m_offset) = (uintptr_t)m_value.GetAsUInt64();
+ if (PTRACE(PT_SETDBREGS, m_tid, (caddr_t)®s, 0) < 0)
+ m_result = false;
+ else
+ m_result = true;
+}
+
+//------------------------------------------------------------------------------
/// @class ReadGPROperation
/// @brief Implements ProcessMonitor::ReadGPR.
class ReadGPROperation : public Operation
@@ -1175,7 +1258,7 @@
case 0:
case TRAP_TRACE:
if (log)
- log->Printf ("ProcessMonitor::%s() received trace event, tid = %" PRIu64, __FUNCTION__, tid);
+ log->Printf ("ProcessMonitor::%s() received trace event, tid = %" PRIu64 " : si_code = %d", __FUNCTION__, tid, info->si_code);
message = ProcessMessage::Trace(tid);
break;
@@ -1464,6 +1547,28 @@
}
bool
+ProcessMonitor::ReadDebugRegisterValue(lldb::tid_t tid, unsigned offset,
+ const char *reg_name, unsigned size,
+ lldb_private::RegisterValue &value)
+{
+ bool result;
+ ReadDebugRegOperation op(tid, offset, size, value, result);
+ DoOperation(&op);
+ return result;
+}
+
+bool
+ProcessMonitor::WriteDebugRegisterValue(lldb::tid_t tid, unsigned offset,
+ const char *reg_name,
+ const lldb_private::RegisterValue &value)
+{
+ bool result;
+ WriteDebugRegOperation op(tid, offset, value, result);
+ DoOperation(&op);
+ return result;
+}
+
+bool
ProcessMonitor::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
{
bool result;
diff --git a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
index 84bbac1..4c8198f 100644
--- a/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
+++ b/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
@@ -116,6 +116,23 @@
WriteRegisterValue(lldb::tid_t tid, unsigned offset, const char *reg_name,
const lldb_private::RegisterValue &value);
+ /// Reads the contents from the debug register identified by the given
+ /// (architecture dependent) offset.
+ ///
+ /// This method is provided for use by RegisterContextFreeBSD derivatives.
+ bool
+ ReadDebugRegisterValue(lldb::tid_t tid, unsigned offset,
+ const char *reg_name, unsigned size,
+ lldb_private::RegisterValue &value);
+
+ /// Writes the given value to the debug register identified by the given
+ /// (architecture dependent) offset.
+ ///
+ /// This method is provided for use by RegisterContextFreeBSD derivatives.
+ bool
+ WriteDebugRegisterValue(lldb::tid_t tid, unsigned offset,
+ const char *reg_name,
+ const lldb_private::RegisterValue &value);
/// Reads all general purpose registers into the specified buffer.
bool
ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size);