PING: RFR: 8241439: jdk.NativeLibraryEvent hooks all opened regular files

[Chihiro Ito]

Hi Yasumasa,

In the following code, like the if statement in the base variable, you
should strictly use 0 and NULL.
if (top < phdr _ top) {

Regards,
Chihiro

2020年6月4日(木) 20:26 Yasumasa Suenaga <suenaga at oss.nttdata.com>:
>
> Hi all,
>
> Could you review this change?
>
> >>    JBS: https://bugs.openjdk.java.net/browse/JDK-8241439
> >>    webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8241439/webrev.01/
>
> I want to merge it to JDK 15.
> I've got a reviewer, then I need one more reviewer to push.
>
>
> Regards,
>
> Yasumasa
>
>
> On 2020/05/26 9:25, Yasumasa Suenaga wrote:
> > Hi all,
> >
> > I've sent review request last month, but nobody has reviewed. Could you review it?
> >
> >>    JBS: https://bugs.openjdk.java.net/browse/JDK-8241439
> >>    webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8241439/webrev.01/
> >
> > os::get_loaded_modules_info() has introduced in JDK-8056242, and it says this function is for dll/so/dylibs.
> > In fact, os::get_loaded_modules_info() uses EnumProcessModules() in Windows.
> >
> > In Linux, get_loaded_modules_info() depends on /proc/<PID>/maps, so it hooks regular files (e.g. JAR, CDS archive), and hooks multiple memory regions by one shared library.
> > We should merge same library to one event, and should not hook regular files (not shared library).
> >
> > All comments are welcome.
> >
> >
> > Thanks,
> >
> > Yasumasa
> >
> >
> > On 2020/04/16 9:30, Yasumasa Suenaga wrote:
> >> PING: Could you review it?
> >>
> >>    JBS: https://bugs.openjdk.java.net/browse/JDK-8241439
> >>    webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8241439/webrev.01/
> >>
> >>
> >> Yasumasa
> >>
> >>
> >> On 2020/04/09 16:00, Yasumasa Suenaga wrote:
> >>> Hi all,
> >>>
> >>> Please review this change:
> >>>
> >>>    JBS: https://bugs.openjdk.java.net/browse/JDK-8241439
> >>>    webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8241439/webrev.00/
> >>>
> >>> HotSpot has os::get_loaded_modules_info() to get all loaded native libraries, however it would call callback in twice on same library on Linux. Also it would call callback even if the file is not a library.
> >>>
> >>> We can see this problem in jdk.NativeLibrary JFR event as below:
> >>>
> >>>
> >>> ```
> >>> jdk.NativeLibrary {
> >>>     startTime = 16:59:06.621
> >>>     name = "/usr/lib64/libc-2.30.so"
> >>>     baseAddress = 0x7FDB06ACC000
> >>>     topAddress = 0x7FDB06AF1000
> >>> }
> >>>
> >>> jdk.NativeLibrary {
> >>>     startTime = 16:59:06.621
> >>>     name = "/usr/lib64/libc-2.30.so"
> >>>     baseAddress = 0x7FDB06AF1000
> >>>     topAddress = 0x7FDB06C40000
> >>> }
> >>>
> >>>      :
> >>>
> >>> ```
> >>>
> >>> ```
> >>> jdk.NativeLibrary {
> >>>     startTime = 16:59:06.621
> >>>     name = "/home/ysuenaga/OpenJDK/jdk/build/linux-x86_64-server-fastdebug/images/jdk/lib/server/classes.jsa"
> >>>     baseAddress = 0x800000000
> >>>     topAddress = 0x800007000
> >>> }
> >>> ```
> >>>
> >>> This change uses dl_iterate_phdr() to get them, so these problem has gone.
> >>>
> >>>
> >>> Thanks,
> >>>
> >>> Yasumasa