From dfa91fac7ecddd8b2c4c6459cc69396f5ec7e0a5 Mon Sep 17 00:00:00 2001
From: Carlo Landmeter <clandmeter@gmail.com>
Date: Tue, 9 Aug 2016 21:48:38 +0200
Subject: [PATCH] Revert "[MDEV-9127] Crash reporter often fails to show the
 query that crashed"

This reverts commit 7d4a7d8c5861e6587176052ea71c30ab12a49084.
---
 include/my_stacktrace.h |  2 +-
 mysys/stacktrace.c      | 30 ++++--------------------------
 sql/signal_handler.cc   | 23 +----------------------
 3 files changed, 6 insertions(+), 49 deletions(-)

diff --git a/include/my_stacktrace.h b/include/my_stacktrace.h
index fad6e53..fb2525e 100644
--- a/include/my_stacktrace.h
+++ b/include/my_stacktrace.h
@@ -45,7 +45,7 @@ C_MODE_START
 #if defined(HAVE_STACKTRACE) || defined(HAVE_BACKTRACE)
 void my_init_stacktrace();
 void my_print_stacktrace(uchar* stack_bottom, ulong thread_stack);
-int my_safe_print_str(const char* val, int max_len);
+void my_safe_print_str(const char* val, int max_len);
 void my_write_core(int sig);
 #if BACKTRACE_DEMANGLE
 char *my_demangle(const char *mangled_name, int *status);
diff --git a/mysys/stacktrace.c b/mysys/stacktrace.c
index 3956592..4cc767f 100644
--- a/mysys/stacktrace.c
+++ b/mysys/stacktrace.c
@@ -129,32 +129,13 @@ static int safe_print_str(const char *addr, int max_len)
 
 #endif
 
-/*
-  Attempt to print a char * pointer as a string.
-
-  SYNOPSIS
-    Prints either until the end of string ('\0'), or max_len characters have
-    been printed.
-
-  RETURN VALUE
-    0  Pointer was within the heap address space.
-       The string was printed fully, or until the end of the heap address space.
-    1  Pointer is outside the heap address space. Printed as invalid.
-
-  NOTE
-    On some systems, we can have valid pointers outside the heap address space.
-    This is through the use of mmap inside malloc calls. When this function
-    returns 1, it does not mean 100% that the pointer is corrupted.
-*/
-
-int my_safe_print_str(const char* val, int max_len)
+void my_safe_print_str(const char* val, int max_len)
 {
   char *heap_end;
 
 #ifdef __linux__
-  // Try and make use of /proc filesystem to safely print memory contents.
   if (!safe_print_str(val, max_len))
-    return 0;
+    return;
 #endif
 
   heap_end= (char*) sbrk(0);
@@ -162,14 +143,12 @@ int my_safe_print_str(const char* val, int max_len)
   if (!PTR_SANE(val))
   {
     my_safe_printf_stderr("%s", "is an invalid pointer");
-    return 1;
+    return;
   }
 
   for (; max_len && PTR_SANE(val) && *val; --max_len)
     my_write_stderr((val++), 1);
   my_safe_printf_stderr("%s", "\n");
-
-  return 0;
 }
 
 #if defined(HAVE_PRINTSTACK)
@@ -748,7 +727,7 @@ void my_write_core(int unused)
 }
 
 
-int my_safe_print_str(const char *val, int len)
+void my_safe_print_str(const char *val, int len)
 {
   __try
   {
@@ -758,7 +737,6 @@ int my_safe_print_str(const char *val, int len)
   {
     my_safe_printf_stderr("%s", "is an invalid string pointer");
   }
-  return 0;
 }
 #endif /*__WIN__*/
 
diff --git a/sql/signal_handler.cc b/sql/signal_handler.cc
index 9dd3e53..9077b24 100644
--- a/sql/signal_handler.cc
+++ b/sql/signal_handler.cc
@@ -65,12 +65,6 @@ extern "C" sig_handler handle_fatal_signal(int sig)
 #ifdef HAVE_STACKTRACE
   THD *thd;
 #endif
-  /*
-     This flag remembers if the query pointer was found invalid.
-     We will try and print the query at the end of the signal handler, in case
-     we're wrong.
-  */
-  bool print_invalid_query_pointer= false;
 
   if (segfaulted)
   {
@@ -207,12 +201,7 @@ extern "C" sig_handler handle_fatal_signal(int sig)
       "Some pointers may be invalid and cause the dump to abort.\n");
 
     my_safe_printf_stderr("Query (%p): ", thd->query());
-    if (my_safe_print_str(thd->query(), MY_MIN(65536U, thd->query_length())))
-    {
-      // Query was found invalid. We will try to print it at the end.
-      print_invalid_query_pointer= true;
-    }
-
+    my_safe_print_str(thd->query(), MY_MIN(65536U, thd->query_length()));
     my_safe_printf_stderr("\nConnection ID (thread ID): %lu\n",
                           (ulong) thd->thread_id);
     my_safe_printf_stderr("Status: %s\n\n", kreason);
@@ -276,16 +265,6 @@ extern "C" sig_handler handle_fatal_signal(int sig)
       "\"mlockall\" bugs.\n");
   }
 
-  if (print_invalid_query_pointer)
-  {
-    my_safe_printf_stderr(
-        "\nWe think the query pointer is invalid, but we will try "
-        "to print it anyway. \n"
-        "Query: ");
-    my_write_stderr(thd->query(), MY_MIN(65536U, thd->query_length()));
-    my_safe_printf_stderr("\n\n");
-  }
-
 #ifdef HAVE_WRITE_CORE
   if (test_flags & TEST_CORE_ON_SIGNAL)
   {
-- 
2.9.1