[SOLVED] API to get android system properties is removed in arm64 platforms

API to get android system properties is removed in arm64 platforms

I am using __system_property_get() from sys/system_properties.h to get a system property. I am trying to use r10c ndk because I need arm64 toolchain.

__system_property_get() is defined in libc.so. Below is the readelf output of libc.so for armv5/armv7a.

readelf -Ws libc.so | grep property_get

       194: 00009100    20 FUNC    GLOBAL DEFAULT    4 __system_property_get
       198: 00009100    20 FUNC    GLOBAL DEFAULT    4 __system_property_get

But, looks like it has been removed for arm64 version! I am getting a linker error saying it is not defined. I analyzed all the shared libraries of arm64 but none of them have that symbol.

Is there an alternate API to get the system property in the native code?

Thank you!

Solution

In older NDKs this was not an officially supported API. It was mistakenly exposed to the 32-bit ABIs early on, but wasn't exposed to the 64-bit ABIs until it was officially supported. Regardless, it is exposed by the system at all API levels, so newer NDKs are able to use this regardless of ABI or minSdkVersion.