Changeset 1649 for zzufTweet

Timestamp:

Jan 11, 2007, 11:21:11 AM (13 years ago)

Author:

Sam Hocevar

Message:

• Better realloc dummy implementation.

File:

• zzuf/trunk/src/load-mem.c (modified) (6 diffs)

zzuf/trunk/src/load-mem.c

@@ -54 +54 @@
 #include "fd.h"
 
-/* TODO: mremap, maybe brk/sbrk */
+/* TODO: mremap, maybe brk/sbrk (haha) */
 
 /* Library functions that we divert */
@@ -107 +107 @@
 }
 
-/* 32k of ugly static memory for programs that call us *before* we’re
- * initialised */
-static uint64_t dummy_buffer[4096];
+/* We need a static memory buffer because some functions call memory
+ * allocation routines before our library is loaded. Hell, even dlsym()
+ * calls calloc(), so we need to do something about it */
+#define DUMMY_BYTES 655360 /* 640 kB ought to be enough for anybody */
+static uint64_t dummy_buffer[DUMMY_BYTES / 8];
 static int dummy_offset = 0;
+#define DUMMY_START ((uintptr_t)dummy_buffer)
+#define DUMMY_STOP ((uintptr_t)dummy_buffer + DUMMY_BYTES)
 
 void *calloc(size_t nmemb, size_t size)
@@ -117 +121 @@
     if(!calloc_orig)
     {
-        int i = (nmemb * size + 7) / 8;
         ret = dummy_buffer + dummy_offset;
-        dummy_offset += i;
-        /* Calloc says we must zero the data */
-        memset(ret, 0, size);
+        memset(ret, 0, (nmemb * size + 7) / 8);
+        dummy_offset += (nmemb * size + 7) / 8;
         return ret;
     }
@@ -135 +137 @@
     if(!malloc_orig)
     {
-        int i = (size + 7) / 8;
         ret = dummy_buffer + dummy_offset;
-        dummy_offset += i;
+        dummy_offset += (size + 7) / 8;
         return ret;
     }
@@ -148 +149 @@
 void free(void *ptr)
 {
-    if((uintptr_t)ptr >= (uintptr_t)dummy_buffer
-       && (uintptr_t)ptr <= (uintptr_t)dummy_buffer + sizeof(dummy_buffer))
+    if((uintptr_t)ptr >= DUMMY_START && (uintptr_t)ptr < DUMMY_STOP)
         return;
     LOADSYM(free);
@@ -158 +158 @@
 {
     void *ret;
-    if((uintptr_t)ptr >= (uintptr_t)dummy_buffer
-       && (uintptr_t)ptr <= (uintptr_t)dummy_buffer + sizeof(dummy_buffer))
-        return ptr; /* FIXME: who would call realloc() so early? */
+    if((uintptr_t)ptr >= DUMMY_START && (uintptr_t)ptr < DUMMY_STOP)
+    {
+        ret = dummy_buffer + dummy_offset;
+        memcpy(ret, ptr, size);
+        dummy_offset += (size + 7) * 8;
+        return ret;
+    }
     LOADSYM(realloc);
     ret = realloc_orig(ptr, size);