Support loading libraries to a reserved address.
Add flags and parameters to android_dlopen_ext() to allow loading a
library at an already-reserved fixed address. If the library to be
loaded will not fit within the space reserved, then the linker will
either fail, or allocate its own address space as usual, according to
which flag has been specified. This behaviour only applies to the
specific library requested; any other libraries loaded as dependencies
will be loaded in the normal fashion.
There is a new gtest included to cover the functionality added.
Bug: 13005501
Change-Id: I5d1810375b20fc51ba6a9b3191a25f9792c687f1
diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index 5de39c6..3ae0965 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -24,12 +24,27 @@
/* bitfield definitions for android_dlextinfo.flags */
enum {
+ /* When set, the reserved_addr and reserved_size fields must point to an
+ * already-reserved region of address space which will be used to load the
+ * library if it fits. If the reserved region is not large enough, the load
+ * will fail.
+ */
+ ANDROID_DLEXT_RESERVED_ADDRESS = 0x1,
+
+ /* As DLEXT_RESERVED_ADDRESS, but if the reserved region is not large enough,
+ * the linker will choose an available address instead.
+ */
+ ANDROID_DLEXT_RESERVED_ADDRESS_HINT = 0x2,
+
/* Mask of valid bits */
- ANDROID_DLEXT_VALID_FLAG_BITS = 0,
+ ANDROID_DLEXT_VALID_FLAG_BITS = ANDROID_DLEXT_RESERVED_ADDRESS |
+ ANDROID_DLEXT_RESERVED_ADDRESS_HINT,
};
typedef struct {
int flags;
+ void* reserved_addr;
+ size_t reserved_size;
} android_dlextinfo;
extern void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo);