RFR: 8201616: Hotspot crashes on linux-sparc after 8189941

[Thomas Stüfe]

Good catch! Proposed fix is fine.

You earned that beer :)

..Thomas

On Tue, Apr 17, 2018 at 9:48 PM, John Paul Adrian Glaubitz
<glaubitz at physik.fu-berlin.de> wrote:
> Hi!
>
> After having rebuilt OpenJDK several dozen times over several days and bisecting
> for several hours today, I finally found the culprit for the segfault I am seeing
> on linux-sparc which is JDK-8189941 [1].
>
> Looking at the SPARC-specific changes [2], I noticed the change in os_solaris_sparc.cpp
> to use os::is_poll_address() instead of os::get_polling_page() when a SIGSEGV is caught
> which was missing in os_linux_sparc.cpp.
>
> Thus, I made that change to os_linux_sparc.cpp as well:
>
> diff --git a/src/hotspot/os_cpu/linux_sparc/os_linux_sparc.cpp b/src/hotspot/os_cpu/linux_sparc/os_linux_sparc.cpp
> --- a/src/hotspot/os_cpu/linux_sparc/os_linux_sparc.cpp
> +++ b/src/hotspot/os_cpu/linux_sparc/os_linux_sparc.cpp
> @@ -374,7 +374,7 @@
>  }
>
>  inline static bool checkPollingPage(address pc, address fault, address* stub) {
> -  if (fault == os::get_polling_page()) {
> +  if (os::is_poll_address(fault)) {
>      *stub = SharedRuntime::get_poll_stub(pc);
>      return true;
>    }
>
> And voila, the crash is gone \o/.
>
> Please review the change in [3] and invite me over a cold one at next FOSDEM :-).
>
> Cheers,
> Adrian
>
>> [1] http://hg.openjdk.java.net/jdk/jdk/rev/0ce0ac68ace7
>> [2] http://hg.openjdk.java.net/jdk/jdk/rev/0ce0ac68ace7#l39.1
>> [3] http://cr.openjdk.java.net/~glaubitz/8201616/webrev.00/
>
> --
>  .''`.  John Paul Adrian Glaubitz
> : :' :  Debian Developer - glaubitz at debian.org
> `. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
>   `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913