Bug#31891 Meaningful stack trace

On crashes generate a user-friendly resolved and demangled stack
trace when libc provides the necessary functions (newer libc on i386,
x86_64, powerpc, ia64, alpha and s390). Otherwise print a numeric
stack trace as before, relying on resolve_stack_dump utility.


configure.in:
  Add check for backtrace headers, backtrace functions and if
  __cxa_demangle (libstdc++) is available at link time.
sql/mysqld.cc:
  Print the value of the THD::killed variable when dumping. In
  some circumstances knowing if the thread was killed makes
  debugging easier.
sql/stacktrace.c:
  Use the glibc backtrace function when available and demangle
  C++ function names if the __cxa_demangle function is available.
sql/stacktrace.h:
  Locally export and wrap in C linkage the C++ function __cxa_demangle
  if available.

configure.in

@@ -813,8 +813,8 @@ AC_CHECK_HEADERS(fcntl.h float.h floatingpoint.h ieeefp.h limits.h \
  sys/timeb.h sys/types.h sys/un.h sys/vadvise.h sys/wait.h term.h \
  unistd.h utime.h sys/utime.h termio.h termios.h sched.h crypt.h alloca.h \
  sys/ioctl.h malloc.h sys/malloc.h sys/ipc.h sys/shm.h linux/config.h \
- sys/prctl.h \
- sys/resource.h sys/param.h port.h ieeefp.h)
+ sys/prctl.h sys/resource.h sys/param.h port.h ieeefp.h \
+ execinfo.h)
 
 AC_CHECK_HEADERS([xfs/xfs.h])
 
@@ -2041,7 +2041,7 @@ AC_CHECK_FUNCS(alarm bcmp bfill bmove bsearch bzero \
   sighold sigset sigthreadmask port_create sleep \
   snprintf socket stpcpy strcasecmp strerror strsignal strnlen strpbrk strstr \
   strtol strtoll strtoul strtoull tell tempnam thr_setconcurrency vidattr \
-  posix_fallocate)
+  posix_fallocate backtrace backtrace_symbols backtrace_symbols_fd)
 
 #
 #
@@ -2331,6 +2331,21 @@ then
 fi
 AC_MSG_RESULT("$netinet_inc")
 
+AC_LANG_SAVE
+AC_LANG_CPLUSPLUS
+AC_CHECK_HEADERS(cxxabi.h)
+AC_CACHE_CHECK([checking for abi::__cxa_demangle], mysql_cv_cxa_demangle,
+[AC_TRY_LINK([#include <cxxabi.h>], [
+  char *foo= 0; int bar= 0;
+  foo= abi::__cxa_demangle(foo, foo, 0, &bar);
+], [mysql_cv_cxa_demangle=yes], [mysql_cv_cxa_demangle=no])])
+AC_LANG_RESTORE
+
+if test "x$mysql_cv_cxa_demangle" = xyes; then
+  AC_DEFINE(HAVE_ABI_CXA_DEMANGLE, 1,
+            [Define to 1 if you have the `abi::__cxa_demangle' function.])
+fi
+
 #--------------------------------------------------------------------
 # Check for requested features
 #--------------------------------------------------------------------

sql/mysqld.cc

@@ -2182,6 +2182,16 @@ static void check_data_home(const char *path)
 #define UNSAFE_DEFAULT_LINUX_THREADS 200
 #endif
 
+
+#if BACKTRACE_DEMANGLE
+#include <cxxabi.h>
+extern "C" char *my_demangle(const char *mangled_name, int *status)
+{
+  return abi::__cxa_demangle(mangled_name, NULL, NULL, status);
+}
+#endif
+
+
 extern "C" sig_handler handle_segfault(int sig)
 {
   time_t curr_time;
@@ -2253,10 +2263,29 @@ the thread stack. Please read http://dev.mysql.com/doc/mysql/en/linux.html\n\n",
   }
   if (thd)
   {
+    const char *kreason= "UNKNOWN";
+    switch (thd->killed) {
+    case THD::NOT_KILLED:
+      kreason= "NOT_KILLED";
+      break;
+    case THD::KILL_BAD_DATA:
+      kreason= "KILL_BAD_DATA";
+      break;
+    case THD::KILL_CONNECTION:
+      kreason= "KILL_CONNECTION";
+      break;
+    case THD::KILL_QUERY:
+      kreason= "KILL_QUERY";
+      break;
+    case THD::KILLED_NO_VALUE:
+      kreason= "KILLED_NO_VALUE";
+      break;
+    }
     fprintf(stderr, "Trying to get some variables.\n\
 Some pointers may be invalid and cause the dump to abort...\n");
     safe_print_str("thd->query", thd->query, 1024);
     fprintf(stderr, "thd->thread_id=%lu\n", (ulong) thd->thread_id);
+    fprintf(stderr, "thd->killed=%s\n", kreason);
   }
   fprintf(stderr, "\
 The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains\n\

sql/stacktrace.c

@@ -17,11 +17,16 @@
 #include "stacktrace.h"
 #include <signal.h>
 #include <my_pthread.h>
+#include <m_string.h>
 
 #ifdef HAVE_STACKTRACE
 #include <unistd.h>
 #include <strings.h>
 
+#if HAVE_EXECINFO_H
+#include <execinfo.h>
+#endif
+
 #define PTR_SANE(p) ((p) && (char*)(p) >= heap_start && (char*)(p) <= heap_end)
 
 char *heap_start;
@@ -93,9 +98,68 @@ inline uint32* find_prev_pc(uint32* pc, uchar** fp)
 }
 #endif /* defined(__alpha__) && defined(__GNUC__) */
 
+#if BACKTRACE_DEMANGLE
+static void my_demangle_symbols(char **addrs, int n)
+{
+  int status, i;
+  char *begin, *end, *demangled;
+
+  for (i= 0; i < n; i++)
+  {
+    demangled= NULL;
+    begin= strchr(addrs[i], '(');
+    end= begin ? strchr(begin, '+') : NULL;
+
+    if (begin && end)
+    {
+      *begin++= *end++= '\0';
+      demangled= my_demangle(begin, &status);
+      if (!demangled || status)
+      {
+        demangled= NULL;
+        begin[-1]= '(';
+        end[-1]= '+';
+      }
+    }
+
+    if (demangled)
+      fprintf(stderr, "%s(%s+%s\n", addrs[i], demangled, end);
+    else
+      fprintf(stderr, "%s\n", addrs[i]);
+  }
+}
+#endif
+
+
+#if HAVE_BACKTRACE
+static void backtrace_current_thread(void)
+{
+  void *addrs[128];
+  char **strings= NULL;
+  int n = backtrace(addrs, array_elements(addrs));
+#if BACKTRACE_DEMANGLE
+  if ((strings= backtrace_symbols(addrs, n)))
+  {
+    my_demangle_symbols(strings, n);
+    free(strings);
+  }
+#endif
+#if HAVE_BACKTRACE_SYMBOLS_FD
+  if (!strings)
+  {
+    backtrace_symbols_fd(addrs, n, fileno(stderr));
+  }
+#endif
+}
+#endif
+
 
 void  print_stacktrace(uchar* stack_bottom, ulong thread_stack)
 {
+#if HAVE_BACKTRACE
+  backtrace_current_thread();
+  return;
+#endif
   uchar** fp;
   uint frame_count = 0, sigreturn_frame_count;
 #if defined(__alpha__) && defined(__GNUC__)

sql/stacktrace.h

@@ -17,6 +17,14 @@
 extern "C" {
 #endif
 
+#if HAVE_BACKTRACE && HAVE_BACKTRACE_SYMBOLS && HAVE_CXXABI_H && HAVE_ABI_CXA_DEMANGLE
+#define BACKTRACE_DEMANGLE 1
+#endif
+
+#if BACKTRACE_DEMANGLE
+char *my_demangle(const char *mangled_name, int *status);
+#endif
+
 #ifdef TARGET_OS_LINUX
 #if defined(HAVE_STACKTRACE) || (defined (__x86_64__) || defined (__i386__) || (defined(__alpha__) && defined(__GNUC__)))
 #undef HAVE_STACKTRACE