cpukit: Add libdebugger, a remote debugger agent for GDB.

1 files changed, 577 insertions, 0 deletions

diff --git a/cpukit/libdebugger/rtems-debugger-threads.c b/cpukit/libdebugger/rtems-debugger-threads.c
new file mode 100644
index 0000000000..89c1b9eb13
--- /dev/null
+++ b/cpukit/libdebugger/rtems-debugger-threads.c
@@ -0,0 +1,577 @@
+/*
+ * Copyright (c) 2016 Chris Johns <chrisj@rtems.org>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <rtems.h>
+#include <rtems/score/statesimpl.h>
+#include <rtems/score/threadimpl.h>
+
+#include <rtems/debugger/rtems-debugger-server.h>
+
+#include "rtems-debugger-target.h"
+#include "rtems-debugger-threads.h"
+
+static const char const* excludes_defaults[] =
+{
+  "TIME",
+  "_BSD",
+  "IRQS",
+  "DBSs",
+  "DBSe",
+};
+
+static void
+rtems_debugger_thread_free(rtems_debugger_threads* threads)
+{
+  rtems_debugger_block_destroy(&threads->current);
+  rtems_debugger_block_destroy(&threads->registers);
+  rtems_debugger_block_destroy(&threads->excludes);
+  rtems_debugger_block_destroy(&threads->stopped);
+  rtems_debugger_block_destroy(&threads->steppers);
+  threads->next = 0;
+}
+
+int
+rtems_debugger_thread_create(void)
+{
+  rtems_debugger_threads* threads;
+  int                     r;
+
+  threads = calloc(1, sizeof(rtems_debugger_threads));
+  if (threads == NULL) {
+    errno = ENOMEM;
+    rtems_debugger_printf("error: rtems-db: thread: threads alloc: (%d) %s\n",
+                          errno, strerror(errno));
+    return -1;
+  }
+
+  r = rtems_debugger_block_create(&threads->current,
+                                  RTEMS_DEBUGGER_THREAD_BLOCK_SIZE,
+                                  sizeof(rtems_debugger_thread));
+  if (r < 0) {
+    rtems_debugger_thread_free(threads);
+    free(threads);
+    rtems_debugger_printf("error: rtems-db: thread: current alloc: (%d) %s\n",
+                          errno, strerror(errno));
+    return -1;
+  }
+
+  r = rtems_debugger_block_create(&threads->registers,
+                                  RTEMS_DEBUGGER_THREAD_BLOCK_SIZE,
+                                  rtems_debugger_target_reg_size());
+  if (r < 0) {
+    rtems_debugger_thread_free(threads);
+    free(threads);
+    rtems_debugger_printf("error: rtems-db: thread: registers alloc: (%d) %s\n",
+                          errno, strerror(errno));
+    return -1;
+  }
+
+  r = rtems_debugger_block_create(&threads->excludes,
+                                  RTEMS_DEBUGGER_THREAD_BLOCK_SIZE,
+                                  sizeof(rtems_id));
+  if (r < 0) {
+    rtems_debugger_thread_free(threads);
+    free(threads);
+    rtems_debugger_printf("error: rtems-db: thread: exlcudes alloc: (%d) %s\n",
+                          errno, strerror(errno));
+    return -1;
+  }
+
+  r = rtems_debugger_block_create(&threads->stopped,
+                                  RTEMS_DEBUGGER_THREAD_BLOCK_SIZE,
+                                  sizeof(rtems_id));
+  if (r < 0) {
+    rtems_debugger_thread_free(threads);
+    free(threads);
+    rtems_debugger_printf("error: rtems-db: thread: stopped alloc: (%d) %s\n",
+                          errno, strerror(errno));
+    return -1;
+  }
+
+  r = rtems_debugger_block_create(&threads->steppers,
+                                  RTEMS_DEBUGGER_THREAD_BLOCK_SIZE,
+                                  sizeof(rtems_debugger_thread_stepper));
+  if (r < 0) {
+    rtems_debugger_thread_free(threads);
+    free(threads);
+    rtems_debugger_printf("error: rtems-db: thread: steppers alloc: (%d) %s\n",
+                          errno, strerror(errno));
+    return -1;
+  }
+
+  rtems_debugger->threads = threads;
+
+  return rtems_debugger_thread_system_suspend();
+}
+
+int
+rtems_debugger_thread_destroy(void)
+{
+  rtems_debugger_threads* threads = rtems_debugger->threads;
+  rtems_debugger_thread_system_resume(true);
+  rtems_debugger_thread_free(threads);
+  free(threads);
+  rtems_debugger->threads = NULL;
+  return 0;
+}
+
+int
+rtems_debugger_thread_find_index(rtems_id id)
+{
+  rtems_debugger_threads* threads = rtems_debugger->threads;
+  rtems_debugger_thread*  current = rtems_debugger_thread_current(threads);
+  int                     r = -1;
+  if (threads != NULL) {
+    size_t i;
+    for (i = 0; i < threads->current.level; ++i) {
+      if (id == 0 || current[i].id == id) {
+        r = i;
+        break;
+      }
+    }
+  }
+  return r;
+}
+
+static bool
+snapshot_thread(rtems_tcb* tcb, void* arg)
+{
+  rtems_debugger_threads* threads = rtems_debugger->threads;
+  rtems_id                id = tcb->Object.id;
+  char                    name[RTEMS_DEBUGGER_THREAD_NAME_SIZE];
+  bool                    exclude = false;
+  size_t                  i;
+
+  /*
+   * The only time the threads pointer is NULL is a realloc error so we stop
+   * processing threads. There is no way to stop the iterator.
+   */
+  if (rtems_debugger_thread_current(threads) == NULL)
+    return true;
+
+  /*
+   * Filter the threads.
+   */
+  switch (rtems_object_id_get_api(id)) {
+  case OBJECTS_NO_API:
+  case OBJECTS_INTERNAL_API:
+    exclude = true;
+    break;
+  default:
+    rtems_object_get_name(id, sizeof(name), (char*) &name[0]);
+    for (i = 0; i < RTEMS_DEBUGGER_NUMOF(excludes_defaults); ++i) {
+      if (strcmp(excludes_defaults[i], name) == 0) {
+        exclude = true;
+        break;
+      }
+    }
+    break;
+  }
+
+  if (exclude) {
+    rtems_id* excludes;
+    int       r;
+    r = rtems_debugger_block_resize(&threads->excludes);
+    if (r < 0) {
+      rtems_debugger_thread_free(threads);
+      return true;
+    }
+    excludes = rtems_debugger_thread_excludes(threads);
+    excludes[threads->excludes.level++] = id;
+  }
+  else {
+    rtems_debugger_thread* current;
+    DB_UINT*               registers;
+    rtems_debugger_thread* thread;
+    int                    r;
+
+    r = rtems_debugger_block_resize(&threads->current);
+    if (r < 0) {
+      rtems_debugger_thread_free(threads);
+      return true;
+    }
+    r = rtems_debugger_block_resize(&threads->registers);
+    if (r < 0) {
+      rtems_debugger_thread_free(threads);
+      return true;
+    }
+
+    current = rtems_debugger_thread_current(threads);
+    registers = rtems_debugger_thread_registers(threads);
+
+    thread = &current[threads->current.level++];
+    thread->registers =
+        &registers[threads->registers.level++ * rtems_debugger_target_reg_num()];
+
+    thread->tcb    = tcb;
+    thread->id     = id;
+    thread->flags  = 0;
+    thread->signal = 0;
+    thread->frame  = NULL;
+    memcpy((void*) &thread->name[0], &name[0], sizeof(thread->name));
+
+    /*
+     * See if there is a valid exception stack frame and if the thread is being
+     * debugged.
+     */
+    r = rtems_debugger_target_set_exception_frame(thread);
+    if (r < 0) {
+        rtems_debugger_printf("error: rtems-db: thread: snap: %08lx: not valid frame\n",
+                              id);
+    }
+
+    /*
+     * Read the target registers into the thread register array.
+     */
+    rtems_debugger_target_read_regs(thread);
+
+    /*
+     * Debugger threads are stopped for breakpoint, segv or other errors have
+     * the RTEMS_DEBUGGER_THREAD_FLAG_DEBUGGING set.
+     */
+    if (rtems_debugger_thread_flag(thread,
+                                   RTEMS_DEBUGGER_THREAD_FLAG_DEBUGGING)) {
+      rtems_id* stopped;
+      r = rtems_debugger_block_resize(&threads->stopped);
+      if (r < 0) {
+        rtems_debugger_thread_free(threads);
+        return true;
+      }
+      stopped = rtems_debugger_thread_stopped(threads);
+      stopped[threads->stopped.level++] = id;
+    }
+    else {
+      rtems_status_code sc;
+      sc = rtems_task_suspend(id);
+      if (sc != RTEMS_SUCCESSFUL && sc != RTEMS_ALREADY_SUSPENDED) {
+        rtems_debugger_printf("error: rtems-db: thread: suspend: %08lx: %s\n",
+                              id, rtems_status_text(sc));
+        r = -1;
+      }
+    }
+
+    if (rtems_debugger_server_flag(RTEMS_DEBUGGER_FLAG_VERBOSE))
+      rtems_debugger_printf("rtems-db: sys: thd: %08lx: signal: %d\n",
+                            id, thread->signal);
+
+    /*
+     * Pick up the first non-zero signal.
+     */
+    if (rtems_debugger->signal == 0) {
+      rtems_debugger->signal = thread->signal;
+    }
+  }
+
+  return false;
+}
+
+int
+rtems_debugger_thread_system_suspend(void)
+{
+  rtems_debugger_threads* threads = rtems_debugger->threads;
+  int                     r = -1;
+  if (threads != NULL && rtems_debugger_thread_current(threads) != NULL) {
+    if (rtems_debugger_verbose())
+      rtems_debugger_printf("rtems-db: sys:    : suspending\n");
+    r = rtems_debugger_target_swbreak_remove();
+    if (r == 0) {
+      rtems_debugger_thread* current;
+      threads->current.level = 0;
+      threads->registers.level = 0;
+      threads->stopped.level = 0;
+      threads->excludes.level = 0;
+      threads->steppers.level = 0;
+      rtems_task_iterate(snapshot_thread, NULL);
+      current = rtems_debugger_thread_current(threads);
+      if (current == NULL) {
+        rtems_debugger_printf("error: rtems-db: thread: snapshot: (%d) %s\n",
+                              errno, strerror(errno));
+        r = -1;
+      }
+      else {
+        rtems_id* stopped;
+        /*
+         * If there are no stopped threads pick the first one in the current
+         * table and return that.
+         */
+        threads->selector_gen = 0;
+        threads->selector_cont = 0;
+        stopped = rtems_debugger_thread_stopped(threads);
+        if (threads->stopped.level == 0 && threads->current.level > 0) {
+          stopped[threads->stopped.level++] = current[0].id;
+        }
+        if (threads->stopped.level > 0) {
+          threads->selector_gen =
+            rtems_debugger_thread_find_index(stopped[0]);
+          if (threads->selector_gen < 0)
+            threads->selector_gen = 0;
+        }
+      }
+    }
+    else {
+      errno = EIO;
+    }
+  }
+  return r;
+}
+
+int
+rtems_debugger_thread_system_resume(bool detaching)
+{
+  rtems_debugger_threads* threads = rtems_debugger->threads;
+  rtems_debugger_thread*  current;
+  int                     r = 0;
+  current = rtems_debugger_thread_current(threads);
+  if (threads != NULL && current != NULL) {
+    size_t i;
+    if (rtems_debugger_verbose())
+      rtems_debugger_printf("rtems-db: sys:    : resuming\n");
+    if (!detaching)
+      r = rtems_debugger_target_swbreak_insert();
+    if (r == 0) {
+      for (i = 0; i < threads->current.level; ++i) {
+        rtems_debugger_thread* thread = &current[i];
+        rtems_status_code      sc;
+        int                    rr;
+        /*
+         * Check if resuming, which is continuing, a step, or stepping a range.
+         */
+        if (detaching ||
+            rtems_debugger_thread_flag(thread,
+                                       RTEMS_DEBUGGER_THREAD_FLAG_RESUME)) {
+          if (!detaching) {
+            rr = rtems_debugger_target_write_regs(thread);
+            if (rr < 0 && r == 0)
+              r = rr;
+            if (rtems_debugger_thread_flag(thread,
+                                           RTEMS_DEBUGGER_THREAD_FLAG_STEP_INSTR)) {
+              rr = rtems_debugger_target_thread_stepping(thread);
+              if (rr < 0 && r == 0)
+                r = rr;
+            }
+          }
+          sc = rtems_task_resume(thread->id);
+          if (sc != RTEMS_SUCCESSFUL) {
+            rtems_debugger_printf("error: rtems-db: thread: resume: %08lx: %s\n",
+                                  thread->id, rtems_status_text(sc));
+          }
+          thread->flags &= ~(RTEMS_DEBUGGER_THREAD_FLAG_CONTINUE |
+                             RTEMS_DEBUGGER_THREAD_FLAG_STEP);
+          thread->signal = 0;
+        }
+      }
+      /*
+       * Excludes are not cleared so the exception handler can find the
+       * excluded thread.
+       */
+      threads->current.level = 0;
+      threads->registers.level = 0;
+      threads->stopped.level = 0;
+    }
+    else {
+      r = -1;
+      errno = EIO;
+    }
+  }
+  return r;
+}
+
+int
+rtems_debugger_thread_continue(rtems_debugger_thread* thread)
+{
+  thread->flags |= RTEMS_DEBUGGER_THREAD_FLAG_CONTINUE;
+  return 0;
+}
+
+int
+rtems_debugger_thread_continue_all(void)
+{
+  rtems_debugger_threads* threads = rtems_debugger->threads;
+  rtems_debugger_thread*  current;
+  int                     r = 0;
+  current = rtems_debugger_thread_current(threads);
+  if (threads != NULL && current != NULL) {
+    size_t i;
+    for (i = 0; i < threads->current.level; ++i) {
+      rtems_debugger_thread* thread = &current[i];
+      int                    r;
+      r = rtems_debugger_thread_continue(thread);
+      if (r < 0)
+        break;
+    }
+  }
+  else {
+    r = -1;
+    errno = EIO;
+  }
+  return r;
+}
+
+int
+rtems_debugger_thread_step(rtems_debugger_thread* thread)
+{
+  thread->flags |= RTEMS_DEBUGGER_THREAD_FLAG_STEP;
+  return 0;
+}
+
+int
+rtems_debugger_thread_stepping(rtems_debugger_thread* thread,
+                               DB_UINT                start,
+                               DB_UINT                end)
+{
+  /* add lock */
+  rtems_debugger_threads*        threads = rtems_debugger->threads;
+  rtems_debugger_thread_stepper* stepper;
+  int                            r;
+  /*
+   * The resize will automatically extend the block when we are full. The
+   * steppers are cleared in suspend by setting the level to 0.
+   */
+  r = rtems_debugger_block_resize(&threads->steppers);
+  if (r < 0) {
+    rtems_debugger_thread_free(threads);
+    return -1;
+  }
+  stepper = rtems_debugger_thread_steppers(threads);
+  stepper = &stepper[threads->steppers.level];
+  stepper->thread = thread;
+  stepper->start = start;
+  stepper->end = end;
+  threads->steppers.level++;
+  thread->flags |= RTEMS_DEBUGGER_THREAD_FLAG_STEPPING;
+  return 0;
+}
+
+const rtems_debugger_thread_stepper*
+rtems_debugger_thread_is_stepping(rtems_id id, DB_UINT pc)
+{
+  /* add lock */
+  rtems_debugger_threads*        threads = rtems_debugger->threads;
+  rtems_debugger_thread_stepper* stepper;
+  size_t                         i;
+  stepper = rtems_debugger_thread_steppers(threads);
+  for (i = 0; i < threads->steppers.level; ++i, ++stepper) {
+    if (stepper->thread->id == id) {
+      if (pc == stepper->start || (pc > stepper->start && pc < stepper->end))
+        return stepper;
+      break;
+    }
+  }
+  return NULL;
+}
+
+int
+rtems_debugger_thread_current_priority(rtems_debugger_thread* thread)
+{
+  return _Thread_Get_priority(thread->tcb);
+}
+
+int
+rtems_debugger_thread_real_priority(rtems_debugger_thread* thread)
+{
+  return thread->tcb->Real_priority.priority;
+}
+
+int
+rtems_debugger_thread_state(rtems_debugger_thread* thread)
+{
+  return thread->tcb->current_state;
+}
+
+int
+rtems_debugger_thread_state_str(rtems_debugger_thread* thread,
+                                char*                  buffer,
+                                size_t                 size)
+{
+  struct mapper {
+    const char const* label;
+    DB_UINT           mask;
+  };
+  const struct mapper map[] = {
+    { "DELAY",  STATES_DELAYING },
+    { "DORM",   STATES_DORMANT },
+    { "LIFE",   STATES_LIFE_IS_CHANGING },
+    { "SUSP",   STATES_SUSPENDED },
+    { "Wbar",   STATES_WAITING_FOR_BARRIER },
+    { "Wbuf",   STATES_WAITING_FOR_BUFFER },
+    { "Wcvar",  STATES_WAITING_FOR_CONDITION_VARIABLE },
+    { "Wevnt",  STATES_WAITING_FOR_EVENT },
+    { "Wisig",  STATES_INTERRUPTIBLE_BY_SIGNAL },
+    { "Wjatx",  STATES_WAITING_FOR_JOIN_AT_EXIT },
+    { "Wjoin",  STATES_WAITING_FOR_JOIN },
+    { "Wmsg" ,  STATES_WAITING_FOR_MESSAGE },
+    { "Wmutex", STATES_WAITING_FOR_MUTEX },
+    { "WRATE",  STATES_WAITING_FOR_PERIOD },
+    { "Wrpc",   STATES_WAITING_FOR_RPC_REPLY },
+    { "Wrwlk",  STATES_WAITING_FOR_RWLOCK },
+    { "Wseg",   STATES_WAITING_FOR_SEGMENT },
+    { "Wsem",   STATES_WAITING_FOR_SEMAPHORE },
+    { "Wsig",   STATES_WAITING_FOR_SIGNAL },
+    { "Wslcnd", STATES_WAITING_FOR_SYS_LOCK_CONDITION },
+    { "Wslftx", STATES_WAITING_FOR_SYS_LOCK_FUTEX },
+    { "Wslmtx", STATES_WAITING_FOR_SYS_LOCK_MUTEX },
+    { "Wslsem", STATES_WAITING_FOR_SYS_LOCK_SEMAPHORE },
+    { "Wsysev", STATES_WAITING_FOR_SYSTEM_EVENT },
+    { "Wtime",  STATES_WAITING_FOR_TIME },
+    { "Wwkup",  STATES_WAITING_FOR_BSD_WAKEUP },
+    { "ZOMBI",  STATES_ZOMBIE },
+  };
+  DB_UINT state = thread->tcb->current_state;
+  if (state == STATES_READY) {
+    strcpy(buffer, "READY");
+  }
+  else {
+    char*  start = buffer;
+    size_t i;
+    buffer[0] = '\0';
+    buffer[size - 1] = '\0';
+    for (i = 0; size > 0 && i < RTEMS_DEBUGGER_NUMOF(map); ++i) {
+      if ((map[i].mask & state) != 0) {
+        size_t l = snprintf(buffer, size - 1, "%s ", map[i].label);
+        buffer += l;
+        size -= l;
+      }
+    }
+    if (buffer != start)
+      *(buffer - 1) = '\0';
+  }
+  return 0;
+}
+
+unsigned long
+rtems_debugger_thread_stack_size(rtems_debugger_thread* thread)
+{
+  return thread->tcb->Start.Initial_stack.size;
+}
+
+void*
+rtems_debugger_thread_stack_area(rtems_debugger_thread* thread)
+{
+  return thread->tcb->Start.Initial_stack.area;
+}