An implementation of the JVMDebugger interface. The basic debug + facilities are implemented through ptrace interface in the JNI code + (libsaproc.so). Library maps and symbol table management are done in + JNI.
+ +NOTE that since we have the notion of fetching "Java + primitive types" from the remote process (which might have + different sizes than we expect) we have a bootstrapping + problem. We need to know the sizes of these types before we can + fetch them. The current implementation solves this problem by + requiring that it be configured with these type sizes before they + can be fetched. The readJ(Type) routines here will throw a + RuntimeException if they are called before the debugger is + configured with the Java primitive type sizes.
*/ + +public class BsdDebuggerLocal extends DebuggerBase implements BsdDebugger { + private boolean useGCC32ABI; + private boolean attached; + private long p_ps_prochandle; // native debugger handle + private boolean isCore; + + // CDebugger support + private BsdCDebugger cdbg; + + // threadList and loadObjectList are filled by attach0 method + private List threadList; + private List loadObjectList; + + // called by native method lookupByAddress0 + private ClosestSymbol createClosestSymbol(String name, long offset) { + return new ClosestSymbol(name, offset); + } + + // called by native method attach0 + private LoadObject createLoadObject(String fileName, long textsize, + long base) { + File f = new File(fileName); + Address baseAddr = newAddress(base); + return new SharedObject(this, fileName, f.length(), baseAddr); + } + + // native methods + + private native static void init0() + throws DebuggerException; + private native void attach0(int pid) + throws DebuggerException; + private native void attach0(String execName, String coreName) + throws DebuggerException; + private native void detach0() + throws DebuggerException; + private native long lookupByName0(String objectName, String symbol) + throws DebuggerException; + private native ClosestSymbol lookupByAddress0(long address) + throws DebuggerException; + private native long[] getThreadIntegerRegisterSet0(int lwp_id) + throws DebuggerException; + private native byte[] readBytesFromProcess0(long address, long numBytes) + throws DebuggerException; + public native static int getAddressSize() ; + + // Note on Bsd threads are really processes. When target process is + // attached by a serviceability agent thread, only that thread can do + // ptrace operations on the target. This is because from kernel's point + // view, other threads are just separate processes and they are not + // attached to the target. When they attempt to make ptrace calls, + // an ESRCH error will be returned as kernel believes target is not + // being traced by the caller. + // To work around the problem, we use a worker thread here to handle + // all JNI functions that are making ptrace calls. + + interface WorkerThreadTask { + public void doit(BsdDebuggerLocal debugger) throws DebuggerException; + } + + class BsdDebuggerLocalWorkerThread extends Thread { + BsdDebuggerLocal debugger; + WorkerThreadTask task; + DebuggerException lastException; + + public BsdDebuggerLocalWorkerThread(BsdDebuggerLocal debugger) { + this.debugger = debugger; + setDaemon(true); + } + + public void run() { + synchronized (workerThread) { + for (;;) { + if (task != null) { + lastException = null; + try { + task.doit(debugger); + } catch (DebuggerException exp) { + lastException = exp; + } + task = null; + workerThread.notifyAll(); + } + + try { + workerThread.wait(); + } catch (InterruptedException x) {} + } + } + } + + public WorkerThreadTask execute(WorkerThreadTask task) throws DebuggerException { + synchronized (workerThread) { + this.task = task; + workerThread.notifyAll(); + while (this.task != null) { + try { + workerThread.wait(); + } catch (InterruptedException x) {} + } + if (lastException != null) { + throw new DebuggerException(lastException); + } else { + return task; + } + } + } + } + + private BsdDebuggerLocalWorkerThread workerThread = null; + + //---------------------------------------------------------------------- + // Implementation of Debugger interface + // + + /**machDesc may not be null.
+ +useCache should be set to true if debugging is being done + locally, and to false if the debugger is being created for the + purpose of supporting remote debugging.
*/ + public BsdDebuggerLocal(MachineDescription machDesc, + boolean useCache) throws DebuggerException { + this.machDesc = machDesc; + utils = new DebuggerUtilities(machDesc.getAddressSize(), + machDesc.isBigEndian()) { + public void checkAlignment(long address, long alignment) { + // Need to override default checkAlignment because we need to + // relax alignment constraints on Bsd/x86 + if ( (address % alignment != 0) + &&(alignment != 8 || address % 4 != 0)) { + throw new UnalignedAddressException( + "Trying to read at address: " + + addressValueToString(address) + + " with alignment: " + alignment, + address); + } + } + }; + + if (useCache) { + // FIXME: re-test necessity of cache on Bsd, where data + // fetching is faster + // Cache portion of the remote process's address space. + // Fetching data over the socket connection to dbx is slow. + // Might be faster if we were using a binary protocol to talk to + // dbx, but would have to test. For now, this cache works best + // if it covers the entire heap of the remote process. FIXME: at + // least should make this tunable from the outside, i.e., via + // the UI. This is a cache of 4096 4K pages, or 16 MB. The page + // size must be adjusted to be the hardware's page size. + // (FIXME: should pick this up from the debugger.) + if (getCPU().equals("ia64")) { + initCache(16384, parseCacheNumPagesProperty(1024)); + } else { + initCache(4096, parseCacheNumPagesProperty(4096)); + } + } + + workerThread = new BsdDebuggerLocalWorkerThread(this); + workerThread.start(); + } + + /** From the Debugger interface via JVMDebugger */ + public boolean hasProcessList() throws DebuggerException { + return false; + } + + /** From the Debugger interface via JVMDebugger */ + public List getProcessList() throws DebuggerException { + throw new DebuggerException("getProcessList not implemented yet"); + } + + private void checkAttached() throws DebuggerException { + if (attached) { + if (isCore) { + throw new DebuggerException("attached to a core dump already"); + } else { + throw new DebuggerException("attached to a process already"); + } + } + } + + private void requireAttach() { + if (! attached) { + throw new RuntimeException("not attached to a process or a core!"); + } + } + + /* called from attach methods */ + private void findABIVersion() throws DebuggerException { + if (lookupByName0("libjvm.so", "__vt_10JavaThread") != 0 || + lookupByName0("libjvm_g.so", "__vt_10JavaThread") != 0) { + // old C++ ABI + useGCC32ABI = false; + } else { + // new C++ ABI + useGCC32ABI = true; + } + } + + /** From the Debugger interface via JVMDebugger */ + public synchronized void attach(int processID) throws DebuggerException { + checkAttached(); + threadList = new ArrayList(); + loadObjectList = new ArrayList(); + class AttachTask implements WorkerThreadTask { + int pid; + public void doit(BsdDebuggerLocal debugger) { + debugger.attach0(pid); + debugger.attached = true; + debugger.isCore = false; + findABIVersion(); + } + } + + AttachTask task = new AttachTask(); + task.pid = processID; + workerThread.execute(task); + } + + /** From the Debugger interface via JVMDebugger */ + public synchronized void attach(String execName, String coreName) { + checkAttached(); + threadList = new ArrayList(); + loadObjectList = new ArrayList(); + attach0(execName, coreName); + attached = true; + isCore = true; + findABIVersion(); + } + + /** From the Debugger interface via JVMDebugger */ + public synchronized boolean detach() { + if (!attached) { + return false; + } + + threadList = null; + loadObjectList = null; + + if (isCore) { + detach0(); + attached = false; + return true; + } else { + class DetachTask implements WorkerThreadTask { + boolean result = false; + + public void doit(BsdDebuggerLocal debugger) { + debugger.detach0(); + debugger.attached = false; + result = true; + } + } + + DetachTask task = new DetachTask(); + workerThread.execute(task); + return task.result; + } + } + + /** From the Debugger interface via JVMDebugger */ + public Address parseAddress(String addressString) + throws NumberFormatException { + long addr = utils.scanAddress(addressString); + if (addr == 0) { + return null; + } + return new BsdAddress(this, addr); + } + + /** From the Debugger interface via JVMDebugger */ + public String getOS() { + return PlatformInfo.getOS(); + } + + /** From the Debugger interface via JVMDebugger */ + public String getCPU() { + return PlatformInfo.getCPU(); + } + + public boolean hasConsole() throws DebuggerException { + return false; + } + + public String consoleExecuteCommand(String cmd) throws DebuggerException { + throw new DebuggerException("No debugger console available on Bsd"); + } + + public String getConsolePrompt() throws DebuggerException { + return null; + } + + /* called from lookup */ + private long handleGCC32ABI(long addr, String symbol) throws DebuggerException { + if (useGCC32ABI && symbol.startsWith("_ZTV")) { + return addr + (2 * machDesc.getAddressSize()); + } else { + return addr; + } + } + + /** From the SymbolLookup interface via Debugger and JVMDebugger */ + public synchronized Address lookup(String objectName, String symbol) { + requireAttach(); + if (!attached) { + return null; + } + + if (isCore) { + long addr = lookupByName0(objectName, symbol); + return (addr == 0)? null : new BsdAddress(this, handleGCC32ABI(addr, symbol)); + } else { + class LookupByNameTask implements WorkerThreadTask { + String objectName, symbol; + Address result; + + public void doit(BsdDebuggerLocal debugger) { + long addr = debugger.lookupByName0(objectName, symbol); + result = (addr == 0 ? null : new BsdAddress(debugger, handleGCC32ABI(addr, symbol))); + } + } + + LookupByNameTask task = new LookupByNameTask(); + task.objectName = objectName; + task.symbol = symbol; + workerThread.execute(task); + return task.result; + } + } + + /** From the SymbolLookup interface via Debugger and JVMDebugger */ + public synchronized OopHandle lookupOop(String objectName, String symbol) { + Address addr = lookup(objectName, symbol); + if (addr == null) { + return null; + } + return addr.addOffsetToAsOopHandle(0); + } + + /** From the Debugger interface */ + public MachineDescription getMachineDescription() { + return machDesc; + } + + //---------------------------------------------------------------------- + // Implementation of ThreadAccess interface + // + + /** From the ThreadAccess interface via Debugger and JVMDebugger */ + public ThreadProxy getThreadForIdentifierAddress(Address addr) { + return new BsdThread(this, addr); + } + + /** From the ThreadAccess interface via Debugger and JVMDebugger */ + public ThreadProxy getThreadForThreadId(long id) { + return new BsdThread(this, id); + } + + //---------------------------------------------------------------------- + // Internal routines (for implementation of BsdAddress). + // These must not be called until the MachineDescription has been set up. + // + + /** From the BsdDebugger interface */ + public String addressValueToString(long address) { + return utils.addressValueToString(address); + } + + /** From the BsdDebugger interface */ + public BsdAddress readAddress(long address) + throws UnmappedAddressException, UnalignedAddressException { + long value = readAddressValue(address); + return (value == 0 ? null : new BsdAddress(this, value)); + } + public BsdAddress readCompOopAddress(long address) + throws UnmappedAddressException, UnalignedAddressException { + long value = readCompOopAddressValue(address); + return (value == 0 ? null : new BsdAddress(this, value)); + } + + /** From the BsdDebugger interface */ + public BsdOopHandle readOopHandle(long address) + throws UnmappedAddressException, UnalignedAddressException, + NotInHeapException { + long value = readAddressValue(address); + return (value == 0 ? null : new BsdOopHandle(this, value)); + } + public BsdOopHandle readCompOopHandle(long address) + throws UnmappedAddressException, UnalignedAddressException, + NotInHeapException { + long value = readCompOopAddressValue(address); + return (value == 0 ? null : new BsdOopHandle(this, value)); + } + + //---------------------------------------------------------------------- + // Thread context access + // + + public synchronized long[] getThreadIntegerRegisterSet(int lwp_id) + throws DebuggerException { + requireAttach(); + if (isCore) { + return getThreadIntegerRegisterSet0(lwp_id); + } else { + class GetThreadIntegerRegisterSetTask implements WorkerThreadTask { + int lwp_id; + long[] result; + public void doit(BsdDebuggerLocal debugger) { + result = debugger.getThreadIntegerRegisterSet0(lwp_id); + } + } + + GetThreadIntegerRegisterSetTask task = new GetThreadIntegerRegisterSetTask(); + task.lwp_id = lwp_id; + workerThread.execute(task); + return task.result; + } + } + + /** Need to override this to relax alignment checks on x86. */ + public long readCInteger(long address, long numBytes, boolean isUnsigned) + throws UnmappedAddressException, UnalignedAddressException { + // Only slightly relaxed semantics -- this is a hack, but is + // necessary on x86 where it seems the compiler is + // putting some global 64-bit data on 32-bit boundaries + if (numBytes == 8) { + utils.checkAlignment(address, 4); + } else { + utils.checkAlignment(address, numBytes); + } + byte[] data = readBytes(address, numBytes); + return utils.dataToCInteger(data, isUnsigned); + } + + // Overridden from DebuggerBase because we need to relax alignment + // constraints on x86 + public long readJLong(long address) + throws UnmappedAddressException, UnalignedAddressException { + utils.checkAlignment(address, jintSize); + byte[] data = readBytes(address, jlongSize); + return utils.dataToJLong(data, jlongSize); + } + + //---------------------------------------------------------------------- + // Address access. Can not be package private, but should only be + // accessed by the architecture-specific subpackages. + + /** From the BsdDebugger interface */ + public long getAddressValue(Address addr) { + if (addr == null) return 0; + return ((BsdAddress) addr).getValue(); + } + + /** From the BsdDebugger interface */ + public Address newAddress(long value) { + if (value == 0) return null; + return new BsdAddress(this, value); + } + + /** From the BsdCDebugger interface */ + public List/*