Changeset ed8b809

Timestamp:

06/02/15 18:53:15 (10 years ago)

Author:

Hal Finkel <hfinkel@…>

Branches:

master

Children:

4c51931

Parents:

6444e03

git-author:

Hal Finkel <hfinkel@…> (06/02/15 18:53:15)

git-committer:

Hal Finkel <hfinkel@…> (06/02/15 18:53:15)

Message:

fixup the wrapping of mmap, etc.

Files:

• README (modified) (1 diff)
• memlog.cpp (modified) (8 diffs)

README

@@ -18 +18 @@
 For statically-linked applications, add the following to your linker flags:
 
-  -Wl,--wrap,malloc,--wrap,free,--wrap,realloc,--wrap,calloc,--wrap,memalign \
+  -Wl,--wrap,malloc,--wrap,valloc,--wrap,realloc,--wrap,calloc,--wrap,memalign,--wrap,free \
+    -Wl,--wrap,posix_memalign,--wrap,mmap,--wrap,mmap64,--wrap,munmap \
     /path/to/memlog/memlog_s.o -lpthread -ldl
 

memlog.cpp

@@ -54 +54 @@
 void *initial_brk = 0;
 
-#ifdef __PIC__
-typedef int (*__real_posix_memalign_t)(void **memptr, size_t alignment,
-                                       size_t size);
-__real_posix_memalign_t __real_posix_memalign = 0;
-#else
-extern "C" {
-extern int __real_posix_memalign(void **memptr, size_t alignment, size_t size);
-}
-#endif
-
 __attribute__((__constructor__))
 static void record_init() {
@@ -255 +245 @@
 }
 
+#ifdef __PIC__
+int (*__real_posix_memalign)(void **memptr, size_t alignment, size_t size) = 0;
+
+void *(*__real_mmap)(void *addr, size_t length, int prot, int flags,
+                     int fd, off_t offset) = 0;
+void *(*__real_mmap64)(void *addr, size_t length, int prot, int flags,
+                       int fd, off64_t offset) = 0;
+int (*__real_munmap)(void *addr, size_t length) = 0;
+#else
+extern "C" {
+extern int __real_posix_memalign(void **memptr, size_t alignment, size_t size);
+
+extern void *__real_mmap(void *addr, size_t length, int prot, int flags,
+                         int fd, off_t offset);
+extern void *__real_mmap64(void *addr, size_t length, int prot, int flags,
+                           int fd, off64_t offset);
+extern int __real_munmap(void *addr, size_t length);
+}
+#endif
+
 // glibc exports its underlying malloc implementation under the name
 // __libc_malloc so that hooks like this can use it.
@@ -265 +275 @@
 extern void __libc_free(void *ptr);
 
-extern void *__mmap(void *addr, size_t length, int prot, int flags,
-                    int fd, off_t offset);
-extern void *__mmap64(void *addr, size_t length, int prot, int flags,
-                      int fd, off64_t offset);
-extern int __munmap(void *addr, size_t length);
-
 #ifdef __PIC__
 #define FUNC(x) x
@@ -392 +396 @@
 #ifdef __PIC__
   if (!__real_posix_memalign)
-    if (!(__real_posix_memalign =
-        (__real_posix_memalign_t) dlsym(RTLD_NEXT, "posix_memalign")))
-      return -1;
+    if (!(*(void **) (&__real_posix_memalign) =
+        dlsym(RTLD_NEXT, "posix_memalign"))) {
+      return ELIBACC;
+    }
 #endif
 
@@ -417 +422 @@
     __builtin_extract_return_addr(__builtin_return_address(0));
 
-  if (in_malloc)
-    return __mmap(addr, length, prot, flags, fd, offset);
-
-  in_malloc = 1;
-
-  void *ptr = __mmap(addr, length, prot, flags, fd, offset);
+#ifdef __PIC__
+  if (!__real_mmap)
+    if (!(*(void **) (&__real_mmap) = dlsym(RTLD_NEXT, "mmap"))) {
+      errno = ELIBACC;
+      return MAP_FAILED;
+    }
+#endif
+
+  if (in_malloc)
+    return __real_mmap(addr, length, prot, flags, fd, offset);
+
+  in_malloc = 1;
+
+  void *ptr = __real_mmap(addr, length, prot, flags, fd, offset);
 
   if (ptr != MAP_FAILED)
@@ -437 +450 @@
     __builtin_extract_return_addr(__builtin_return_address(0));
 
-  if (in_malloc)
-    return __mmap64(addr, length, prot, flags, fd, offset);
-
-  in_malloc = 1;
-
-  void *ptr = __mmap64(addr, length, prot, flags, fd, offset);
+#ifdef __PIC__
+  if (!__real_mmap64)
+    if (!(*(void **) (&__real_mmap64) = dlsym(RTLD_NEXT, "mmap64"))) {
+      errno = ELIBACC;
+      return MAP_FAILED;
+    }
+#endif
+
+  if (in_malloc)
+    return __real_mmap64(addr, length, prot, flags, fd, offset);
+
+  in_malloc = 1;
+
+  void *ptr = __real_mmap64(addr, length, prot, flags, fd, offset);
 
   if (ptr != MAP_FAILED)
@@ -456 +477 @@
     __builtin_extract_return_addr(__builtin_return_address(0));
 
-  if (in_malloc)
-    return __munmap(addr, length);
+#ifdef __PIC__
+  if (!__real_munmap)
+    if (!(*(void **) (&__real_munmap) = dlsym(RTLD_NEXT, "munmap"))) {
+      errno = ELIBACC;
+      return -1;
+    }
+#endif
+
+  if (in_malloc)
+    return __real_munmap(addr, length);
 
   in_malloc = 1;
@@ -463 +492 @@
   record_free(addr, caller);
 
-  int r = __munmap(addr, length);
+  int r = __real_munmap(addr, length);
 
   in_malloc = 0;