RFR: 8220095: Assertion failure when symlink (with different name) is used for lib/modules file

[Harold Seigel]

Hi Jiangli,

The copyright for new test ModulesSymLink.java is correct.

Harold

On 3/7/2019 11:18 AM, Jiangli Zhou wrote:
> Hi Harold,
>
> Thank you so much for the review and checking on the copyright header! 
> Will update the webrev to address your comment.
>
> Thanks and regards,
> Jiangli
>
> On Thu, Mar 7, 2019 at 8:13 AM Harold Seigel <harold.seigel at oracle.com 
> <mailto:harold.seigel at oracle.com>> wrote:
>
>     Hi Jiangli,
>
>     The change looks good.  Could you change the call to strdup() at line
>     710 in classLoader.cpp to os::strdup() ?
>
>     Also, I'm not sure about  the copyright for your new test. I'll ask
>     internally if you are using the right one.
>
>     Thanks! Harold
>
>     On 3/6/2019 6:20 PM, Jiangli Zhou wrote:
>     > Please review the following fix for 8220095.
>     >
>     > webrev: http://cr.openjdk.java.net/~jiangli/8220095/webrev.00/
>     > bug: https://bugs.openjdk.java.net/browse/JDK-8220095
>     >
>     > Symbolic links may be used commonly in some cloud environments.
>     The target
>     > files might have different names than the linked names. The VM
>     crashes when
>     > 'lib/modules' links to a target file with a different name, for
>     example,
>     > lib/modules -> lib/0.
>     >
>     > The usage of the hard-coded MODULES_IMAGE_NAME (used by
>     > ClassLoader::is_modules_image(const char*)) can become
>     problematic in this
>     > case and leads to assertion failures and crashes in this case. The
>     > is_modules_image()
>     > checks always fail even the actual file is the runtime image
>     because the
>     > canonical paths (which might not end with 'modules') are passed
>     in for the
>     > check. The fix is to obtain the real name from the canonical
>     path early
>     > during initialization and use that for the is_modules_image() check.
>     >
>     > Tested with submit repo testing, tier1, tier2, and hotspot
>     runtime tests
>     > locally.
>     >
>     > Thanks!
>     > Jiangli
>