[prev in list] [next in list] [prev in thread] [next in thread] 

List:       openjdk-serviceability-dev
Subject:    Re: SA does not work if executable is DSO
From:       Yasumasa Suenaga <yasuenag () gmail ! com>
Date:       2017-02-07 10:29:58
Message-ID: 26927bfa-a44b-a8b5-3548-5e3611ea0db3 () gmail ! com
[Download RAW message or body]

Hi Andrew,

You can build PIE binaries with files which are provided by redhat-rpm-config as \
below:

```
$ bash configure --with-native-debug-symbols=internal --enable-debug \
--disable-warnings-as-errors --disable-hotspot-gtest \
--with-extra-cflags=-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 \
--with-extra-cxxflags=-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 \
--with-extra-ldflags=-specs=/usr/lib/rpm/redhat/redhat-hardened-ld $ make images
```

If you use OpenJDK 8 in Fedora 25, you can reproduce as below:

1. Run Java App with OpenJDK
      I use java-1.8.0-openjdk-1.8.0.121-1.b14.fc25.x86_64

2. Collect core images via gcore
      $ gcore <PID>

3. Run jstack with LIBSAPROC_DEBUG
```
$ LIBSAPROC_DEBUG=1 jstack /usr/lib/jvm/java-1.8.0-open
jdk-1.8.0.121-1.b14.fc25.x86_64/bin/java core.1031
Attaching to core core.1031 from executable \
/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.121-1.b14.fc25.x86_64/bin/java, please wait... \
libsaproc DEBUG: executable file is not a valid ELF ET_EXEC file Error attaching to \
                core file: Can't attach to the core file
sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the core file
         at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.attach0(Native Method)
            :
```


Thanks,

Yasumasa


On 2017/02/07 19:14, Andrew Haley wrote:
> On 05/02/17 14:25, Yasumasa Suenaga wrote:
> 
> > In modern Linux e.g. Fedora 25, executables are built as DSO for security [1].
> > java command in OpenJDK which is provided by distribution is also DSO.
> > However, SA does not work with DSO executables.
> > 
> > I want to propose the fix as below.
> 
> Please explain what steps are needed to reproduce this problem.  What
> commands did you use?
> 
> Thanks,
> 
> Andrew.
> 
> 


[prev in list] [next in list] [prev in thread] [next in thread]