Does Android NDK support "-z execstack" flag?

Issue

I'm tring to build a executable with android ndk to test shellcode. I set 'LOCAL_CFLAGS := -z execstack' to make the stack executable but it does not work. Doesn't android ndk support '-z execstack' option?

Here's the code:

18 include $(CLEAR_VARS)
19 LOCAL_MODULE := shellcode-test
20 LOCAL_SRC_FILES := src/shellcode-test.c
21 LOCAL_CFLAGS := -z execstack -Wl,--execstack

Check result: only 'RW', no 'E'

$ aarch64-linux-gnu-readelf -l shellcode-test ... GNU_STACK 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 RW 0x10 ...

Solution

Resolved.

Android NDK forces noexecstack options when build executables or libraries. So '-z execstack' in my Android.mk is overridden by NDK's default option:

./build/core/build-binary.mk:LOCAL_CFLAGS += -Wa,--noexecstack ./build/core/build-binary.mk:LOCAL_LDFLAGS += -Wl,-z,noexecstack

Answered By - Juhu