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-rw-r--r--source/Host/common/SoftwareBreakpoint.cpp296
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diff --git a/source/Host/common/SoftwareBreakpoint.cpp b/source/Host/common/SoftwareBreakpoint.cpp
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+//===-- SoftwareBreakpoint.cpp ----------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SoftwareBreakpoint.h"
+
+#include "lldb/Core/Error.h"
+#include "lldb/Core/Log.h"
+#include "lldb/Host/Debug.h"
+#include "lldb/Host/Mutex.h"
+
+#include "NativeProcessProtocol.h"
+
+using namespace lldb_private;
+
+// -------------------------------------------------------------------
+// static members
+// -------------------------------------------------------------------
+
+Error
+SoftwareBreakpoint::CreateSoftwareBreakpoint (NativeProcessProtocol &process, lldb::addr_t addr, size_t size_hint, NativeBreakpointSP &breakpoint_sp)
+{
+ Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_BREAKPOINTS));
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s addr = 0x%" PRIx64, __FUNCTION__, addr);
+
+ // Validate the address.
+ if (addr == LLDB_INVALID_ADDRESS)
+ return Error ("SoftwareBreakpoint::%s invalid load address specified.", __FUNCTION__);
+
+ // Ask the NativeProcessProtocol subclass to fill in the correct software breakpoint
+ // trap for the breakpoint site.
+ size_t bp_opcode_size = 0;
+ const uint8_t *bp_opcode_bytes = NULL;
+ Error error = process.GetSoftwareBreakpointTrapOpcode (size_hint, bp_opcode_size, bp_opcode_bytes);
+
+ if (error.Fail ())
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to retrieve software breakpoint trap opcode: %s", __FUNCTION__, error.AsCString ());
+ return error;
+ }
+
+ // Validate size of trap opcode.
+ if (bp_opcode_size == 0)
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to retrieve any trap opcodes", __FUNCTION__);
+ return Error ("SoftwareBreakpoint::GetSoftwareBreakpointTrapOpcode() returned zero, unable to get breakpoint trap for address 0x%" PRIx64, addr);
+ }
+
+ if (bp_opcode_size > MAX_TRAP_OPCODE_SIZE)
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s cannot support %lu trapcode bytes, max size is %lu", __FUNCTION__, bp_opcode_size, MAX_TRAP_OPCODE_SIZE);
+ return Error ("SoftwareBreakpoint::GetSoftwareBreakpointTrapOpcode() returned too many trap opcode bytes: requires %lu but we only support a max of %lu", bp_opcode_size, MAX_TRAP_OPCODE_SIZE);
+ }
+
+ // Validate that we received opcodes.
+ if (!bp_opcode_bytes)
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to retrieve trap opcode bytes", __FUNCTION__);
+ return Error ("SoftwareBreakpoint::GetSoftwareBreakpointTrapOpcode() returned NULL trap opcode bytes, unable to get breakpoint trap for address 0x%" PRIx64, addr);
+ }
+
+ // Enable the breakpoint.
+ uint8_t saved_opcode_bytes [MAX_TRAP_OPCODE_SIZE];
+ error = EnableSoftwareBreakpoint (process, addr, bp_opcode_size, bp_opcode_bytes, saved_opcode_bytes);
+ if (error.Fail ())
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s: failed to enable new breakpoint at 0x%" PRIx64 ": %s", __FUNCTION__, addr, error.AsCString ());
+ return error;
+ }
+
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s addr = 0x%" PRIx64 " -- SUCCESS", __FUNCTION__, addr);
+
+ // Set the breakpoint and verified it was written properly. Now
+ // create a breakpoint remover that understands how to undo this
+ // breakpoint.
+ breakpoint_sp.reset (new SoftwareBreakpoint (process, addr, saved_opcode_bytes, bp_opcode_bytes, bp_opcode_size));
+ return Error ();
+}
+
+Error
+SoftwareBreakpoint::EnableSoftwareBreakpoint (NativeProcessProtocol &process, lldb::addr_t addr, size_t bp_opcode_size, const uint8_t *bp_opcode_bytes, uint8_t *saved_opcode_bytes)
+{
+ assert (bp_opcode_size <= MAX_TRAP_OPCODE_SIZE && "bp_opcode_size out of valid range");
+ assert (bp_opcode_bytes && "bp_opcode_bytes is NULL");
+ assert (saved_opcode_bytes && "saved_opcode_bytes is NULL");
+
+ Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_BREAKPOINTS));
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s addr = 0x%" PRIx64, __FUNCTION__, addr);
+
+ // Save the original opcodes by reading them so we can restore later.
+ lldb::addr_t bytes_read = 0;
+
+ Error error = process.ReadMemory(addr, saved_opcode_bytes, static_cast<lldb::addr_t> (bp_opcode_size), bytes_read);
+ if (error.Fail ())
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to read memory while attempting to set breakpoint: %s", __FUNCTION__, error.AsCString ());
+ return error;
+ }
+
+ // Ensure we read as many bytes as we expected.
+ if (bytes_read != static_cast<lldb::addr_t> (bp_opcode_size))
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to read memory while attempting to set breakpoint: attempted to read %lu bytes but only read %" PRIu64, __FUNCTION__, bp_opcode_size, bytes_read);
+ return Error ("SoftwareBreakpoint::%s failed to read memory while attempting to set breakpoint: attempted to read %lu bytes but only read %" PRIu64, __FUNCTION__, bp_opcode_size, bytes_read);
+ }
+
+ // Write a software breakpoint in place of the original opcode.
+ lldb::addr_t bytes_written = 0;
+ error = process.WriteMemory (addr, bp_opcode_bytes, static_cast<lldb::addr_t> (bp_opcode_size), bytes_written);
+ if (error.Fail ())
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to write memory while attempting to set breakpoint: %s", __FUNCTION__, error.AsCString ());
+ return error;
+ }
+
+ // Ensure we wrote as many bytes as we expected.
+ if (bytes_written != static_cast<lldb::addr_t> (bp_opcode_size))
+ {
+ error.SetErrorStringWithFormat("SoftwareBreakpoint::%s failed write memory while attempting to set breakpoint: attempted to write %lu bytes but only wrote %" PRIu64, __FUNCTION__, bp_opcode_size, bytes_written);
+ if (log)
+ log->PutCString (error.AsCString ());
+ return error;
+ }
+
+ uint8_t verify_bp_opcode_bytes [MAX_TRAP_OPCODE_SIZE];
+ lldb::addr_t verify_bytes_read = 0;
+ error = process.ReadMemory(addr, verify_bp_opcode_bytes, static_cast<lldb::addr_t> (bp_opcode_size), verify_bytes_read);
+ if (error.Fail ())
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to read memory while attempting to verify the breakpoint set: %s", __FUNCTION__, error.AsCString ());
+ return error;
+ }
+
+ // Ensure we read as many verification bytes as we expected.
+ if (verify_bytes_read != static_cast<lldb::addr_t> (bp_opcode_size))
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s failed to read memory while attempting to verify breakpoint: attempted to read %lu bytes but only read %" PRIu64, __FUNCTION__, bp_opcode_size, verify_bytes_read);
+ return Error ("SoftwareBreakpoint::%s failed to read memory while attempting to verify breakpoint: attempted to read %lu bytes but only read %" PRIu64, __FUNCTION__, bp_opcode_size, verify_bytes_read);
+ }
+
+ if (::memcmp(bp_opcode_bytes, verify_bp_opcode_bytes, bp_opcode_size) != 0)
+ {
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s: verification of software breakpoint writing failed - trap opcodes not successfully read back after writing when setting breakpoint at 0x%" PRIx64, __FUNCTION__, addr);
+ return Error ("SoftwareBreakpoint::%s: verification of software breakpoint writing failed - trap opcodes not successfully read back after writing when setting breakpoint at 0x%" PRIx64, __FUNCTION__, addr);
+ }
+
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s addr = 0x%" PRIx64 " -- SUCCESS", __FUNCTION__, addr);
+
+ return Error ();
+}
+
+// -------------------------------------------------------------------
+// instance-level members
+// -------------------------------------------------------------------
+
+SoftwareBreakpoint::SoftwareBreakpoint (NativeProcessProtocol &process, lldb::addr_t addr, const uint8_t *saved_opcodes, const uint8_t *trap_opcodes, size_t opcode_size) :
+ NativeBreakpoint (addr),
+ m_process (process),
+ m_saved_opcodes (),
+ m_trap_opcodes (),
+ m_opcode_size (opcode_size)
+{
+ assert ( opcode_size > 0 && "setting software breakpoint with no trap opcodes");
+ assert ( opcode_size <= MAX_TRAP_OPCODE_SIZE && "trap opcode size too large");
+
+ ::memcpy (m_saved_opcodes, saved_opcodes, opcode_size);
+ ::memcpy (m_trap_opcodes, trap_opcodes, opcode_size);
+}
+
+Error
+SoftwareBreakpoint::DoEnable ()
+{
+ return EnableSoftwareBreakpoint (m_process, m_addr, m_opcode_size, m_trap_opcodes, m_saved_opcodes);
+}
+
+Error
+SoftwareBreakpoint::DoDisable ()
+{
+ Error error;
+ assert (m_addr && (m_addr != LLDB_INVALID_ADDRESS) && "can't remove a software breakpoint for an invalid address");
+
+ Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_BREAKPOINTS));
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s addr = 0x%" PRIx64, __FUNCTION__, m_addr);
+
+ assert ( (m_opcode_size > 0) && "cannot restore opcodes when there are no opcodes");
+
+ if (m_opcode_size > 0)
+ {
+ // Clear a software breakoint instruction
+ uint8_t curr_break_op [MAX_TRAP_OPCODE_SIZE];
+ bool break_op_found = false;
+ assert (m_opcode_size <= sizeof (curr_break_op));
+
+ // Read the breakpoint opcode
+ lldb::addr_t bytes_read = 0;
+ error = m_process.ReadMemory (m_addr, curr_break_op, m_opcode_size, bytes_read);
+ if (error.Success () && (bytes_read < static_cast<lldb::addr_t> (m_opcode_size)))
+ {
+ error.SetErrorStringWithFormat ("SoftwareBreakpointr::%s addr=0x%" PRIx64 ": tried to read %lu bytes but only read %" PRIu64, __FUNCTION__, m_addr, m_opcode_size, bytes_read);
+ }
+ if (error.Success ())
+ {
+ bool verify = false;
+ // Make sure we have the a breakpoint opcode exists at this address
+ if (::memcmp (curr_break_op, m_trap_opcodes, m_opcode_size) == 0)
+ {
+ break_op_found = true;
+ // We found a valid breakpoint opcode at this address, now restore
+ // the saved opcode.
+ lldb::addr_t bytes_written = 0;
+ error = m_process.WriteMemory (m_addr, m_saved_opcodes, m_opcode_size, bytes_written);
+ if (error.Success () && (bytes_written < static_cast<lldb::addr_t> (m_opcode_size)))
+ {
+ error.SetErrorStringWithFormat ("SoftwareBreakpoint::%s addr=0x%" PRIx64 ": tried to write %lu bytes but only wrote %" PRIu64, __FUNCTION__, m_addr, m_opcode_size, bytes_written);
+ }
+ if (error.Success ())
+ {
+ verify = true;
+ }
+ }
+ else
+ {
+ error.SetErrorString("Original breakpoint trap is no longer in memory.");
+ // Set verify to true and so we can check if the original opcode has already been restored
+ verify = true;
+ }
+
+ if (verify)
+ {
+ uint8_t verify_opcode [MAX_TRAP_OPCODE_SIZE];
+ assert (m_opcode_size <= sizeof (verify_opcode));
+ // Verify that our original opcode made it back to the inferior
+
+ lldb::addr_t verify_bytes_read = 0;
+ error = m_process.ReadMemory (m_addr, verify_opcode, m_opcode_size, verify_bytes_read);
+ if (error.Success () && (verify_bytes_read < static_cast<lldb::addr_t> (m_opcode_size)))
+ {
+ error.SetErrorStringWithFormat ("SoftwareBreakpoint::%s addr=0x%" PRIx64 ": tried to read %lu verification bytes but only read %" PRIu64, __FUNCTION__, m_addr, m_opcode_size, verify_bytes_read);
+ }
+ if (error.Success ())
+ {
+ // compare the memory we just read with the original opcode
+ if (::memcmp (m_saved_opcodes, verify_opcode, m_opcode_size) == 0)
+ {
+ // SUCCESS
+ if (log)
+ log->Printf ("SoftwareBreakpoint::%s addr = 0x%" PRIx64 " -- SUCCESS", __FUNCTION__, m_addr);
+ return error;
+ }
+ else
+ {
+ if (break_op_found)
+ error.SetErrorString("Failed to restore original opcode.");
+ }
+ }
+ else
+ error.SetErrorString("Failed to read memory to verify that breakpoint trap was restored.");
+ }
+ }
+ }
+
+ if (log && error.Fail ())
+ log->Printf ("SoftwareBreakpoint::%s addr = 0x%" PRIx64 " -- FAILED: %s",
+ __FUNCTION__,
+ m_addr,
+ error.AsCString());
+ return error;
+}
+
+bool
+SoftwareBreakpoint::IsSoftwareBreakpoint () const
+{
+ return true;
+}
+