property_get: do argument checking.

Try to verify, at compile time, that the supplied
value buffer is large enough.

There's more we can do here, but this is a good first
pass.

Change-Id: Iac8153826c89114b2755735032423c6744f7a61b

1 files changed, 20 insertions, 0 deletions

diff --git a/include/cutils/properties.h b/include/cutils/properties.h
index 25fd67a..5ec8c2c 100644
--- a/include/cutils/properties.h
+++ b/include/cutils/properties.h
@@ -17,6 +17,9 @@
 #ifndef __CUTILS_PROPERTIES_H
 #define __CUTILS_PROPERTIES_H
 
+#include <sys/cdefs.h>
+#include <stddef.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -62,6 +65,23 @@ enum {
 };
 #endif /*HAVE_SYSTEM_PROPERTY_SERVER*/
 
+#ifdef __BIONIC_FORTIFY_INLINE
+
+extern int __property_get_real(const char *, char *, const char *)
+    __asm__(__USER_LABEL_PREFIX__ "property_get");
+extern void __property_get_too_small_error()
+    __attribute__((__error__("property_get() called with too small of a buffer")));
+
+__BIONIC_FORTIFY_INLINE
+int property_get(const char *key, char *value, const char *default_value) {
+    size_t bos = __builtin_object_size(value, 0);
+    if (bos < PROPERTY_VALUE_MAX) {
+        __property_get_too_small_error();
+    }
+    return __property_get_real(key, value, default_value);
+}
+
+#endif /* __BIONIC_FORTIFY_INLINE */
 
 #ifdef __cplusplus
 }