Re: Prelinking on ARM

[Torsten Polle <Torsten dot Polle at gmx dot de>]

Mark,

Am 02.06.2015 um 20:28 schrieb Mark Wielaard <mjw@redhat.com>:
> On Mon, 2015-06-01 at 22:43 +0200, Torsten Polle wrote:
>> I've a problem with prelinked shared and non-prelinked debug information
>> for the same on ARM. The relative offset to the .text section differs
>> for the prelinked shared library and the non-prelinked debug
>> information. SystemTap only compensates for the difference in the start
>> addresses. I tried to debug the problem, but I've to admit that the
>> problem is well over my head. Could someone give me a hint on this
>> matter?
> 
> Does the testsuite/systemtap.exelib/exelib.exp test work for you?

I've to check. I'm using a cross compile environment, i.e. I only run
passes 1 - 4 on my host (X86) and execute staprun on my target
(ARM). I could provide a small shared library as an example instead.

> # Builds various variants of an executable and a shared library
> # (with gcc/g++, -O0/-O3, prelinked/pie, seperate debuginfo)
> # Then runs tests with a list of execs.
> 
> # Don't enable all sub-tests by default, enable them separately when
> # you want to track down an issue.
> # Enable just the all-in-one test for regular test runs to safe time
> #set subtestlist {lib mark uname ustack cleanup}
> 
> make installcheck RUNTESTFLAGS=exelib.exp
> 
> Which for me on an x86_64 and a armv7hl give:
> 
> Snapshot: version 2.8/0.160, commit release-2.7-126-gf80d9cdb3078
> GCC: 4.8.3 [gcc (GCC) 4.8.3 20140911 (Red Hat 4.8.3-9)]
> Distro: Red Hat Enterprise Linux Workstation release 7.1 (Maipo)
> SElinux: Enforcing
> 
> 
> Running /home/mark/src/systemtap/testsuite/systemtap.exelib/exelib.exp ...
> 
> 		=== systemtap Summary ===
> 
> # of expected passes		376
> 
> Snapshot: version 2.8/0.161, commit release-2.7-160-g1eed3df165bc +
> changes
> GCC: 5.1.1 [gcc (GCC) 5.1.1 20150422 (Red Hat 5.1.1-1)]
> Distro: Fedora release 22 (Twenty Two)
> SElinux: Enforcing
> 
> 
> Running ./systemtap.exelib/exelib.exp ...
> 
> 		=== systemtap Summary ===
> 
> # of expected passes		188
> 
> (arm has half the number of passes since x86_64 actually does twice as
> many tests, for both normal 64bits binaries and for an -m32 binaries.)
> 
> If the above doesn't match what you see on your setup could you enable
> the subtests as indicated in the .exp file and see which particular
> subtests fail (maybe include the relevant parts of the
> testsuite/systemtap.log file).
> 
> Thanks,
> 
> Mark

Thanks,
Torsten