Fix code generation buffer overflow reported by TeLeMan

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3805 c046a42c-6fe2-441c-8c8c-71466251a162

cpu-exec.c

@@ -133,7 +133,7 @@ static TranslationBlock *tb_find_slow(target_ulong pc,
     tb->tc_ptr = tc_ptr;
     tb->cs_base = cs_base;
     tb->flags = flags;
-    cpu_gen_code(env, tb, CODE_GEN_MAX_SIZE, &code_gen_size);
+    cpu_gen_code(env, tb, &code_gen_size);
     code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1));
 
     /* check next page if needed */

exec-all.h

@@ -64,8 +64,9 @@ extern int loglevel;
 int gen_intermediate_code(CPUState *env, struct TranslationBlock *tb);
 int gen_intermediate_code_pc(CPUState *env, struct TranslationBlock *tb);
 void dump_ops(const uint16_t *opc_buf, const uint32_t *opparam_buf);
+unsigned long code_gen_max_block_size(void);
 int cpu_gen_code(CPUState *env, struct TranslationBlock *tb,
-                 int max_code_size, int *gen_code_size_ptr);
+                 int *gen_code_size_ptr);
 int cpu_restore_state(struct TranslationBlock *tb,
                       CPUState *env, unsigned long searched_pc,
                       void *puc);
@@ -94,7 +95,6 @@ static inline int tlb_set_page(CPUState *env, target_ulong vaddr,
     return tlb_set_page_exec(env, vaddr, paddr, prot, mmu_idx, is_softmmu);
 }
 
-#define CODE_GEN_MAX_SIZE        65536
 #define CODE_GEN_ALIGN           16 /* must be >= of the size of a icache line */
 
 #define CODE_GEN_PHYS_HASH_BITS     15

exec.c

@@ -56,7 +56,7 @@
 #endif
 
 /* threshold to flush the translated code buffer */
-#define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
+#define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - code_gen_max_block_size())
 
 #define SMC_BITMAP_USE_THRESHOLD 10
 
@@ -622,7 +622,7 @@ static void tb_gen_code(CPUState *env,
     tb->cs_base = cs_base;
     tb->flags = flags;
     tb->cflags = cflags;
-    cpu_gen_code(env, tb, CODE_GEN_MAX_SIZE, &code_gen_size);
+    cpu_gen_code(env, tb, &code_gen_size);
     code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1));
 
     /* check next page if needed */

translate-all.c

@@ -132,14 +132,27 @@ static void dyngen_labels(long *gen_labels, int nb_gen_labels,
     }
 }
 
+unsigned long code_gen_max_block_size(void)
+{
+    static unsigned long max;
+
+    if (max == 0) {
+#define DEF(s, n, copy_size) max = copy_size > max? copy_size : max;
+#include "opc.h"
+#undef DEF
+        max *= OPC_MAX_SIZE;
+    }
+
+    return max;
+}
+
 /* return non zero if the very first instruction is invalid so that
    the virtual CPU can trigger an exception.
 
    '*gen_code_size_ptr' contains the size of the generated code (host
    code).
 */
-int cpu_gen_code(CPUState *env, TranslationBlock *tb,
-                 int max_code_size, int *gen_code_size_ptr)
+int cpu_gen_code(CPUState *env, TranslationBlock *tb, int *gen_code_size_ptr)
 {
     uint8_t *gen_code_buf;
     int gen_code_size;