Re: How to track the functions in self-written module using SystemTap?

[Nan Xiao <xiaonan830818@gmail.com>]

Hi David,

(1)
>>> Hmm. OK, let's try a couple more things:
>>
>>> 1) It could be that systemtap is missing the module load somehow. So,
>>> try this:
>>
>>> - load the module
>>> - run stap
>>> - exercise the module
>>> - unload the module
>>> - kill stap
>>
>> Still outputs nothing.

> Can you do the same thing here and add '-DDEBUG_KPROBES' to the stap
> command and show us the output?

After adding '-DDEBUG_KPROBES', the stap command still outputs nothing.

(2)
The output of executing "# make installcheck
RUNTESTFLAGS="modules_out_of_tree.exp kmodule.exp"":

# make installcheck RUNTESTFLAGS="modules_out_of_tree.exp kmodule.exp"
make: *** No rule to make target `installcheck'.  Stop.
[root@localhost yum.repos.d]# cd /usr/share/systemtap/testsuite
[root@localhost testsuite]# make installcheck
RUNTESTFLAGS="modules_out_of_tree.exp kmodule.exp"
rmmod uprobes 2>/dev/null
make: [installcheck] Error 1 (ignored)
make  check-DEJAGNU RUNTESTFLAGS="modules_out_of_tree.exp kmodule.exp
--tool_opts \'install \'"
make[1]: Entering directory `/usr/share/systemtap/testsuite'
srcdir='.'; export srcdir; \
EXPECT=expect; export EXPECT; \
if /bin/sh -c "env XDG_DATA_DIRS= SYSTEMTAP_SYNC=1 LANG=C
SYSTEMTAP_TESTREMOTES= SYSTEMTAP_TESTAPPS=
SYSTEMTAP_RUNTIME=/usr/share/systemtap/runtime
SYSTEMTAP_TAPSET=/usr/share/systemtap/tapset
LD_LIBRARY_PATH=/usr/lib64/systemtap CRASH_LIBDIR=/usr/lib64/systemtap
PATH=/usr/bin:$PATH SYSTEMTAP_PATH=/usr/bin
SYSTEMTAP_INCLUDES=/usr/include  PKGLIBDIR=/usr/libexec/systemtap
./execrc runtest --version" > /dev/null 2>&1; then \
  exit_status=0; l='systemtap'; for tool in $l; do \
    if env XDG_DATA_DIRS= SYSTEMTAP_SYNC=1 LANG=C
SYSTEMTAP_TESTREMOTES= SYSTEMTAP_TESTAPPS=
SYSTEMTAP_RUNTIME=/usr/share/systemtap/runtime
SYSTEMTAP_TAPSET=/usr/share/systemtap/tapset
LD_LIBRARY_PATH=/usr/lib64/systemtap CRASH_LIBDIR=/usr/lib64/systemtap
PATH=/usr/bin:$PATH SYSTEMTAP_PATH=/usr/bin
SYSTEMTAP_INCLUDES=/usr/include  PKGLIBDIR=/usr/libexec/systemtap
./execrc runtest  --tool $tool --tool_opts \'\' --srcdir $srcdir
modules_out_of_tree.exp kmodule.exp --tool_opts \'install \'; \
    then :; else exit_status=1; fi; \
  done; \
else echo "WARNING: could not find 'env XDG_DATA_DIRS=
SYSTEMTAP_SYNC=1 LANG=C SYSTEMTAP_TESTREMOTES= SYSTEMTAP_TESTAPPS=
SYSTEMTAP_RUNTIME=/usr/share/systemtap/runtime
SYSTEMTAP_TAPSET=/usr/share/systemtap/tapset
LD_LIBRARY_PATH=/usr/lib64/systemtap CRASH_LIBDIR=/usr/lib64/systemtap
PATH=/usr/bin:$PATH SYSTEMTAP_PATH=/usr/bin
SYSTEMTAP_INCLUDES=/usr/include  PKGLIBDIR=/usr/libexec/systemtap
./execrc runtest'" 1>&2; :;\
fi; \
exit $exit_status
WARNING: Couldn't find the global config file.
kernel location: /usr/lib/debug/lib/modules/3.10.0-123.el7.x86_64.debug/vmlinux
kernel version: 3.10.0-123.el7.x86_64.debug
systemtap location: /usr/bin/stap
systemtap version: version 2.4/0.158, rpm 2.4-14.el7
gcc location: /usr/bin/gcc
gcc version: gcc (GCC) 4.8.2 20140120 (Red Hat 4.8.2-16)
spawn -ignore SIGHUP gcc hello.c -g -m64 -lm -o hello-m64
spawn -ignore SIGHUP gcc hello.c -g -m32 -lm -o hello-m32
spawn -ignore SIGHUP g++ hello.cxx -g -m64 -lm -o hello-m64
spawn -ignore SIGHUP g++ hello.cxx -g -m32 -lm -o hello-m32
Test Run By root on Wed Dec  2 20:08:12 2015
Native configuration is x86_64-unknown-linux-gnu

                === systemtap tests ===

Schedule of variations:
    unix

Running target unix
Using /usr/share/dejagnu/baseboards/unix.exp as board description file
for target.
Using /usr/share/dejagnu/config/unix.exp as generic interface file for target.
Using ./config/unix.exp as tool-and-target-specific interface file.

Host: Linux localhost.localdomain 3.10.0-123.el7.x86_64.debug #1 SMP
Mon May 5 11:24:18 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux
Snapshot: version 2.4/0.158, rpm 2.4-14.el7
GCC: 4.8.2 [gcc (GCC) 4.8.2 20140120 (Red Hat 4.8.2-16)]
Distro: Red Hat Enterprise Linux Server release 7.0 (Maipo)
SElinux: Enforcing


Running ./systemtap.base/kmodule.exp ...

                === systemtap Summary ===

# of expected passes            7
make[1]: Leaving directory `/usr/share/systemtap/testsuite'
if test -n ""; then mail  < systemtap.sum; fi

Thanks!
Best Regards
Nan Xiao


On Thu, Dec 3, 2015 at 5:42 AM, David Smith <dsmith@redhat.com> wrote:
> On 12/01/2015 08:22 PM, Nan Xiao wrote:
>>> Hmm. OK, let's try a couple more things:
>>
>>> 1) It could be that systemtap is missing the module load somehow. So,
>>> try this:
>>
>>> - load the module
>>> - run stap
>>> - exercise the module
>>> - unload the module
>>> - kill stap
>>
>> Still outputs nothing.
>
> Can you do the same thing here and add '-DDEBUG_KPROBES' to the stap
> command and show us the output?
>
>>> 2) It looks like you are running the rpm version. Can you install the
>>> systemtap-testsuite rpm and try the following (as root):
>>
>>> # cd /usr/share/systemtap/testsuite
>>> # make installcheck RUNTESTFLAGS="modules_out_of_tree.exp kmodule.exp"
>>
>>> That should run 2 testcases that test out-of-tree modules and in-tree
>>> modules.
>>
>> The output likes this:
>>
>> # make installcheck RUNTESTFLAGS="modules_out_of_tree.exp kmodule.exp"
>
> ... stuff deleted ...
>
>> spawn -ignore SIGHUP gcc hello.c -g -m32 -lm -o hello-m32
>> /usr/bin/ld: skipping incompatible
>> /usr/lib/gcc/x86_64-redhat-linux/4.8.2/libgcc_s.so when searching for
>> -lgcc_s
>> /usr/bin/ld: cannot find -lgcc_s
>> collect2: error: ld returned 1 exit status
>>
>>
>>
>> **** failed gcc m32 smoke test:
>>
>> /usr/bin/ld: cannot find -lgcc_s
>> collect2: error: ld returned 1 exit status
>>
>> Please install libgcc and glibc development packages for m32
>
> The testsuite checks a few things before starting, one of them being
> that gcc can create 32-bit executables on an x86_64 system. If you want
> to proceed further here, you'll have to do the following:
>
> # yum install glibc.i686 libgcc.i686 glibc-devel.i686 libstdc++-devel.i686
>
> --
> David Smith
> dsmith@redhat.com
> Red Hat
> http://www.redhat.com
> 256.217.0141 (direct)
> 256.837.0057 (fax)