Moving opt-in custom signal handler from UnitTests into RCCL (#550)

* Enable via RCCL_ENABLE_SIGNALHANDLER=1

src/misc/signals.cc

@@ -0,0 +1,82 @@
+/*************************************************************************
+ * Copyright (c) 2022 Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * See LICENSE.txt for license information
+ ************************************************************************/
+
+#ifdef HAVE_BFD
+#include "BfdBacktrace.hpp"
+#endif
+
+#include <unistd.h>
+#include <signal.h>
+#include <execinfo.h>
+#include <string.h>
+#include "param.h"
+#include "debug.h"
+#include <vector>
+
+void sig_handler(int signum)
+{
+  printf("\n[Process: %d] Inside handler function signal: %s (%d)\n", getpid(), strsignal(signum), signum);
+
+#ifdef HAVE_BFD
+  void *addresses[BACKTRACE_MAX];
+  int num_addresses = backtrace(addresses, BACKTRACE_MAX);
+  struct backtrace_file file;
+  backtrace_line line;
+  backtrace_h bckt;
+  bckt.size = 0;
+
+  for (int i = 0; i < num_addresses; ++i)
+  {
+    file.dl.address = (unsigned long)addresses[i];
+    if (dl_lookup_address(&file.dl) && load_file(&file))
+    {
+      bckt.size += get_line_info(&file, 1,
+                                 bckt.lines + bckt.size,
+                                 BACKTRACE_MAX - bckt.size);
+      unload_file(&file);
+    }
+  }
+
+  for (int i=0; i<BACKTRACE_MAX; i++ )
+  {
+    if ((char*)bckt.lines[i].address == NULL) break;
+    printf("%p %s : %s line %u\n", (char*)bckt.lines[i].address,
+           bckt.lines[i].file, bckt.lines[i].function, bckt.lines[i].lineno);
+  }
+#else
+#define BT_BUF_SIZE 1024
+  void *buffer[BT_BUF_SIZE];
+  char **strings;
+
+  int nptrs = backtrace(buffer, BT_BUF_SIZE);
+  strings = backtrace_symbols(buffer, nptrs);
+  for (int j = 0; j < nptrs; j++)
+    printf("%s\n", strings[j]);
+  free (strings);
+#endif
+
+  exit (-1);
+}
+
+RCCL_PARAM(EnableSignalHandler, "ENABLE_SIGNALHANDLER", 0); // Opt-in environment variable for enabling custom signal handler
+
+void RegisterSignalHandlers()
+{
+  if (rcclParamEnableSignalHandler())
+  {
+    INFO(NCCL_INIT, "Enabling custom signal handler");
+
+    std::vector<int> signalsToCatch = {SIGILL, SIGBUS, SIGFPE, SIGSEGV};
+
+    for (auto signum : signalsToCatch)
+    {
+      if (signal(signum, sig_handler) == SIG_ERR)
+      {
+        INFO(NCCL_INIT, "Unable to register signal handler for %s\n", strsignal(signum));
+      }
+    }
+  }
+}