Handle errno properly to avoid corrupt str_parms
A normal sequence of calls is as follows:
str_parms_create_str, str_parms_add_str, str_parms_destroy.
In some cases the destroy caused double free.
str_parms_add_str will clone the input and send it to hashmapPut
for storage. If hashmapPut did not store the strings it will raise
errno = ENOMEM and leave caller with ownership of the strings.
In any of these cases it will be safe to destroy the str_parms.
But what if it wasn't hashmapPut that said NOMEM? What if there
was a stale NOMEM already before a successful hashmapPut?
In that case the strings will be successfully added to the list
(if new), but when str_parms_add_str sees the NOMEM it will free
them anyway, leaving dangling pointers in the str_parms!!
It is the responsibility of the caller to clear errno before any
interesting call. This patch makes sure that str_parms_add_str
reacts only on errno emmitted from hashmapPut.
Change-Id: If87e4bcc482f09e1c66133d33517b152ebdac65f
diff --git a/libcutils/Android.mk b/libcutils/Android.mk
index 93bccb0..635695a 100644
--- a/libcutils/Android.mk
+++ b/libcutils/Android.mk
@@ -91,6 +91,16 @@
LOCAL_CFLAGS += $(hostSmpFlag) -m64
include $(BUILD_HOST_STATIC_LIBRARY)
+# Tests for host
+# ========================================================
+include $(CLEAR_VARS)
+LOCAL_MODULE := tst_str_parms
+LOCAL_CFLAGS += -DTEST_STR_PARMS
+LOCAL_SRC_FILES := str_parms.c hashmap.c memory.c
+LOCAL_STATIC_LIBRARIES := liblog
+LOCAL_MODULE_TAGS := optional
+include $(BUILD_HOST_EXECUTABLE)
+
# Shared and static library for target
# ========================================================