[Qemu-devel] [PATCH 1/1] Fix large memory chunks allocation with tcg_malloc.

[Kirill Batuzov]

An attempt to allocate a large memory chunk after a small one resulted in
circular links in list of pools.  It caused the same memory being
allocated twice for different arrays.

Now pools for large memory chunks are kept in separate list and are
freed during pool reset because current allocator can not reuse them.

Signed-off-by: Kirill Batuzov <batuz...@ispras.ru>
---
 tcg/tcg.c |   14 +++++++++-----
 tcg/tcg.h |    2 +-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 351a0a3..7db8340 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -173,11 +173,9 @@ void *tcg_malloc_internal(TCGContext *s, int size)
         /* big malloc: insert a new pool (XXX: could optimize) */
         p = g_malloc(sizeof(TCGPool) + size);
         p->size = size;
-        if (s->pool_current)
-            s->pool_current->next = p;
-        else
-            s->pool_first = p;
-        p->next = s->pool_current;
+        p->next = s->pool_first_large;
+        s->pool_first_large = p;
+        return p->data;
     } else {
         p = s->pool_current;
         if (!p) {
@@ -208,6 +206,12 @@ void *tcg_malloc_internal(TCGContext *s, int size)
 
 void tcg_pool_reset(TCGContext *s)
 {
+    TCGPool *p, *t;
+    for (p = s->pool_first_large; p; p = t) {
+        t = p->next;
+        g_free(p);
+    }
+    s->pool_first_large = NULL;
     s->pool_cur = s->pool_end = NULL;
     s->pool_current = NULL;
 }
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 5c28239..48d3f17 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -337,7 +337,7 @@ typedef struct TCGContext TCGContext;
 
 struct TCGContext {
     uint8_t *pool_cur, *pool_end;
-    TCGPool *pool_first, *pool_current;
+    TCGPool *pool_first, *pool_current, *pool_first_large;
     TCGLabel *labels;
     int nb_labels;
     TCGTemp *temps; /* globals first, temps after */
-- 
1.7.5.4