util: add debug_memory_check_block(), debug_memory_tag()

The former just checks that the given block is valid by checking
the header and footer.

The later sets the memory block's tag.  With extra debug code, we
can use that for monitoring/checking particular allocations.

Reviewed-by: José Fonseca <jfonseca@vmware.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_debug_memory.c b/src/gallium/auxiliary/util/u_debug_memory.c
index 4bf26a5..4723547 100644
--- a/src/gallium/auxiliary/util/u_debug_memory.c
+++ b/src/gallium/auxiliary/util/u_debug_memory.c
@@ -76,6 +76,7 @@ struct debug_memory_header
 #endif
 
    unsigned magic;
+   unsigned tag;
 };
 
 struct debug_memory_footer
@@ -140,6 +141,7 @@ debug_malloc(const char *file, unsigned line, const char *function,
    hdr->function = function;
    hdr->size = size;
    hdr->magic = DEBUG_MEMORY_MAGIC;
+   hdr->tag = 0;
 #if DEBUG_FREED_MEMORY
    hdr->freed = FALSE;
 #endif
@@ -263,6 +265,7 @@ debug_realloc(const char *file, unsigned line, const char *function,
    new_hdr->function = old_hdr->function;
    new_hdr->size = new_size;
    new_hdr->magic = DEBUG_MEMORY_MAGIC;
+   new_hdr->tag = 0;
 #if DEBUG_FREED_MEMORY
    new_hdr->freed = FALSE;
 #endif
@@ -348,6 +351,58 @@ debug_memory_end(unsigned long start_no)
 
 
 /**
+ * Put a tag (arbitrary integer) on a memory block.
+ * Can be useful for debugging.
+ */
+void
+debug_memory_tag(void *ptr, unsigned tag)
+{
+   struct debug_memory_header *hdr;
+   
+   if (!ptr)
+      return;
+   
+   hdr = header_from_data(ptr);
+   if (hdr->magic != DEBUG_MEMORY_MAGIC) {
+      debug_printf("%s corrupted memory at %p\n", __FUNCTION__, ptr);
+      debug_assert(0);
+   }
+
+   hdr->tag = tag;
+}
+
+
+/**
+ * Check the given block of memory for validity/corruption.
+ */
+void
+debug_memory_check_block(void *ptr)
+{
+   struct debug_memory_header *hdr;
+   struct debug_memory_footer *ftr;
+   
+   if (!ptr)
+      return;
+   
+   hdr = header_from_data(ptr);
+   ftr = footer_from_header(hdr);
+
+   if (hdr->magic != DEBUG_MEMORY_MAGIC) {
+      debug_printf("%s:%u:%s: bad or corrupted memory %p\n",
+                   hdr->file, hdr->line, hdr->function, ptr);
+      debug_assert(0);
+   }
+
+   if (ftr->magic != DEBUG_MEMORY_MAGIC) {
+      debug_printf("%s:%u:%s: buffer overflow %p\n",
+                   hdr->file, hdr->line, hdr->function, ptr);
+      debug_assert(0);
+   }
+}
+
+
+
+/**
  * We can periodically call this from elsewhere to do a basic sanity
  * check of the heap memory we've allocated.
  */