Fixed overrun in key cache if one tried to allocate a key cache

of more than 45G with a key_cache_block_size of 1024 or less.

The problem was that some of the arguments to my_multi_malloc() got to be
more than 4G.

Fix:
- Inntroduced my_multi_malloc_large() that can handle big regions.
- Changed MyISAM and Aria key caches to use my_multi_malloc_large().

I didn't change the default my_multi_malloc() as this would be a too big
patch and we don't allocate 4G blocks anywhere else.

1 files changed, 44 insertions, 0 deletions

diff --git a/mysys/mulalloc.c b/mysys/mulalloc.c
index 9384ed744ad..fceecdc1dc7 100644
--- a/mysys/mulalloc.c
+++ b/mysys/mulalloc.c
@@ -62,3 +62,47 @@ void* my_multi_malloc(myf myFlags, ...)
   va_end(args);
   DBUG_RETURN((void*) start);
 }
+
+
+/*
+  Same as my_multi_malloc, but each entry can be over 4G
+
+  SYNOPSIS
+    my_multi_malloc()
+      myFlags              Flags
+	ptr1, length1      Multiple arguments terminated by null ptr
+	ptr2, length2      ...
+        ...
+	NULL
+*/
+
+void *my_multi_malloc_large(myf myFlags, ...)
+{
+  va_list args;
+  char **ptr,*start,*res;
+  size_t tot_length,length;
+  DBUG_ENTER("my_multi_malloc");
+
+  va_start(args,myFlags);
+  tot_length=0;
+  while ((ptr=va_arg(args, char **)))
+  {
+    length=va_arg(args,ulonglong);
+    tot_length+=ALIGN_SIZE(length);
+  }
+  va_end(args);
+
+  if (!(start=(char *) my_malloc(tot_length, myFlags)))
+    DBUG_RETURN(0); /* purecov: inspected */
+
+  va_start(args,myFlags);
+  res=start;
+  while ((ptr=va_arg(args, char **)))
+  {
+    *ptr=res;
+    length=va_arg(args,ulonglong);
+    res+=ALIGN_SIZE(length);
+  }
+  va_end(args);
+  DBUG_RETURN((void*) start);
+}