RFR: 8009550: PlatformPCSC should load versioned so

[Valerie Peng]

On Thu, 24 Aug 2023 00:53:03 GMT, Andrew John Hughes <andrew at openjdk.org> wrote:

> There is a long standing limitation in the UNIX smartcardio implementation which means it will only look for the `pcsclite` library in two locations; `/usr/lib` and `/usr/local/lib`. It also only searches for an unversioned library.
> 
> On systems that separate libraries from development headers in separate subpackages, the unversioned library is only installed by the `-devel` package, which rarely happens unless the user wants to write their own application using the libpcsclite headers or build someone else's code themselves. An example of this is the [pcsc-lite-libs package on Fedora](https://koji.fedoraproject.org/koji/rpminfo?rpmID=35258843)
> 
> On Debian-based systems, there is also the issue that libraries are now placed inside a subdirectory using a [tuple](https://wiki.debian.org/Multiarch/Tuples) consisting of the instruction set, syscall ABI and libc e.g. `x86_64-linux-gnu`.  So it will not only fail to find the library when only the versioned library is installed (e.g. [libpcsclite1](https://packages.ubuntu.com/kinetic/amd64/libpcsclite1/filelist)) but also when the dev package is also installed (e.g. [libpcsclite-dev](https://packages.ubuntu.com/kinetic/amd64/libpcsclite-dev/filelist)), because the file is in e.g. `/usr/lib/x86_64-linux-gnu/libpcsclite.so`
> 
> This patch makes both cases work. It prefers versioned libraries, as potentially a `libpcsclite.so.2` could become available with a different ABI that the JDK can not work with.  All cases that worked before with just `libpcsclite.so` will still work, but it should also now pick up the library on many additional systems.
> 
> A much simpler patch (search for the versioned symlink instead of unversioned) has been [in the Fedora and RHEL packages for nearly a decade](https://bugzilla.redhat.com/show_bug.cgi?id=910107), and an earlier version of this patch with Debian support has been used in IcedTea builds since 2015. It would be nice to finally fix this upstream.
> 
> Testing:
> 
> Test case:
> ~~~
> import java.lang.reflect.Method;
> 
> public class TestPlatformPCSC {
>     public static void main(String[] args)
>     throws Exception {
>         Class<?> cls = Class.forName("sun.security.smartcardio.PlatformPCSC");
>         Method m = cls.getDeclaredMethod("getLibraryName");
>         m.setAccessible(true);
>         System.err.println(m.invoke(null));
>     }
> }
> ~~~
> 
> 1. With `libpcsclite.so.1` available:
> ~~~
> $ ~/builder/trunk/images/jdk/bin/java --add-opens java.smartcardio/sun.security.smartcardio=ALL-UNNAMED -Djava.security.d...

Marked as reviewed by valeriep (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/15409#pullrequestreview-1594756492