RFR 8087153: EXCEPTION_ACCESS_VIOLATION when CDS RO section vanished on win32

[Daniel D. Daugherty]

On 6/17/15 8:23 PM, Coleen Phillimore wrote:
> Summary: use os::protect_memory() instead of calling 
> os::reserve_memory again
>
> We call mprotect or VirtualProtect on all of the platforms now rather 
> than calling reserve_memory again for the same area.   This is used to 
> make CDS read-only regions read-write if classes are redefined.
>
> This is actually Christian Tornqvist's fix with my encouragement and 
> testing on linux and solaris, and Misha's testing on windows.   We 
> tested jdi tests with -Xshare:on, including the tests for bug 
> https://bugs.openjdk.java.net/browse/JDK-8054386.
>
> open webrev at http://cr.openjdk.java.net/~coleenp/8087153.01/

src/share/vm/runtime/os.hpp
     No comments.

src/share/vm/runtime/os.cpp
     No comments.

src/os/aix/vm/os_aix.cpp
     No comments.

src/os/bsd/vm/os_bsd.cpp
     No comments.

src/os/linux/vm/os_linux.cpp
     No comments.

src/os/solaris/vm/os_solaris.cpp
     No comments.

src/os/windows/vm/os_windows.cpp
     No comments.

src/share/vm/memory/filemap.cpp
     L582:     fatal(err_msg("Unable to remap shared readonly space 
(errno=%d).", errno));
         The above message should change a bit. Perhaps:

         fatal(err_msg("Unable to change shared read-only space to 
read-write (errno=%d).", errno));

         Also, don't know if 'errno' is set by os::protect_memory() 
everywhere.

Dan


> bug link https://bugs.openjdk.java.net/browse/JDK-8087153
>
> Thanks,
> Coleen
>
>
>