Hi Christoph,
It looks like for bsd this code was added to fix JDK-7152800. In that CR
I see the following:
"The attach framework will verify that the file has the same effective
owner and group as the currently running process. This will be true on
linux, since files are created with the effective user and group as
owner. This will NOT be true always on macos, since the file can have a
different group if the temporary directory has a different group than
what we are currently running as."
So it looks like the fix is not necessary for Linux. It wouldn't hurt to
experiment by setting the s-bit on the directory and see if you have the
same problem as macos and AIX.
thanks,
Chris
On 5/4/18 7:29 AM, Langer, Christoph wrote:
Hi,
please review a change for correctly setting the group for the attach
listener file:
Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8202650.0/
<http://cr.openjdk.java.net/%7Eclanger/webrevs/8202650.0/>
Bug: https://bugs.openjdk.java.net/browse/JDK-8202650
<https://bugs.openjdk.java.net/browse/JDK-8202650>
The attach listener file, usually /tmp/.java_pid<pid> is created from
the hotspot JVM process. Usually it will belong to the process user
and group. However, when the directory where it is created has set the
s-bit for groups, the group of the directory is taken. This will cause
errors when the attach client tries to connect and it is checked
whether the group of the attach file matches the client processes' group.
In my webrev I only implemented the change for AIX because we have run
into an issue on that platform. But I can see this code already in
place for attachListener_bsd.cpp. And I’m wondering if this should
also be added to attachListener_linux.cpp because the sticky-bit could
be set with the same effects on Linux, too. Any opinions about that?
Thanks and best regards
Christoph
