Re: gdb failure on simplest hello world program -- oe-selftest

[richard.purdie@linuxfoundation.org]

On Fri, 2018-12-28 at 17:49 +0800, ChenQi wrote:
> On 12/26/2018 07:06 PM, richard.purdie@linuxfoundation.org wrote:
> > On Wed, 2018-12-26 at 10:09 +0800, ChenQi wrote:
> > > Hi All,
> > > 
> > > 'oe-selftest -r package.PackageTests.test_gdb_hardlink_debug'
> > > fails.
> > > I did the tests on both my Fedora27 and ubuntu16.04 servers. They
> > > both 
> > > failed.
> > > I can also reproduce this issue manually.
> > > 
> > > I did some investigation. No clue how to fix this it. So I want
> > > to seek 
> > > help from community.
> > > 
> > > Below is some output from oe-selftest.
> > > [snip]
> > > 2018-12-26 09:27:58,440 - oe-selftest - INFO -
> > > test_gdb_hardlink_debug 
> > > (package.PackageTests)
> > > 2018-12-26 09:37:55,333 - oe-selftest - INFO - gdbtest
> > > /usr/bin/hello1
> > > 2018-12-26 09:37:59,904 - oe-selftest - ERROR - GDB result:
> > > 1: Reading symbols from /usr/bin/hello1...Reading symbols from 
> > > /usr/bin/.debug/hello4...done.
> > > done.
> > > (gdb) Breakpoint 1 at 0x1060: file /usr/include/bits/stdio2.h,
> > > line 107.
> > > (gdb) Starting program: /usr/bin/hello1
> > > 
> > > Breakpoint 1, main () at /usr/include/bits/stdio2.h:107
> > > 107    /usr/include/bits/stdio2.h: No such file or directory.
> > > (gdb) Continuing.
> > > Hello World!
> > > [Inferior 1 (process 312) exited normally]
> > > (gdb)
> > > 2018-12-26 09:38:00,907 - oe-selftest - INFO -  ... FAIL
> > > [snip]
> > > 
> > > The hello world problem is as follows.
> > > $ cat 
> > > meta-selftest/recipes-test/selftest-hardlink/selftest-
> > > hardlink/hello.c
> > > #include <stdio.h>
> > > 
> > > int main() {
> > >      printf("Hello World!\n");
> > > }
> > > 
> > > Some extra information:
> > > 1. Remove '-O2' or '-D_FORTIFY_SOURCE=2', and it works correctly.
> > > 2. Adding some system call like daemon(0,0) before printf also
> > > works.
> > > 3. Reverting poky repo to
> > > 1c048479af7cc98e30f9a33d1f3bef03711544aa, 
> > > which adds this selftest case, does not work. It still fails.
> > > 4. Hongxu confirms that things work on his host.
> > > 5. I also don't see failure about this test case on yocto's
> > > autobuilder.
> > > 
> > > Could somebody help to provide some suggestions?
> > 
> > This is strange and there must be some difference between your
> > configuration and what what we test on the autobuilder or on
> > Hongxu's
> > setup.
>  
> Hi Richard,
> 
> I have talked with Hongxu and we can now both confirm that there does
> exist some problem.
> 
> > Which DISTRO and MACHINE are you using?
>  
> DISTRO is poky
> MACHINE is qemux86.
> 
> It seems that if MACHINE is qemux86-64, the test case could pass. But
> that's just because the test case only checks 'Breakpoint 1, main ()
> at hello.c:4'. See the console output below.
> (gdb) b main
> Breakpoint 1 at 0x1050: file /usr/include/bits/stdio2.h, line 107.
> (gdb) r
> Starting program: /usr/bin/hello1 
> 
> Breakpoint 1, main () at hello.c:4
> 4        printf("Hello World!\n");
> (gdb) c
> Continuing.
> Hello World!
> [Inferior 1 (process 156) exited normally]
> (gdb) q
> 
> Even in this case, the 'b main' does not give correct result. The
> test case passes because 'Breakpoint 1, main () at hello.c:4' is
> there.
> 
> On qemux86, we have:
> (gdb) Breakpoint 1 at 0x1060: file /usr/include/bits/stdio2.h, line
> 107.
> (gdb) Starting program: /usr/bin/hello1 
> 
> Breakpoint 1, main () at /usr/include/bits/stdio2.h:107
> 107    /usr/include/bits/stdio2.h: No such file or directory.
> (gdb) Continuing.
> Hello World!
> [Inferior 1 (process 156) exited normally]
> (gdb)
> 
> > I think the key to resolving this is will be to understanding how
> > to
> > reproduce it...
>  
> Two ways to reproduce the problem:
> 
> I) reproduce it via oe-selftest
> 1) . oe-init-build-env build-selftest
> 2) SANITY_TESTED_DISTROS = ""
> 3) oe-selftest -r package.PackageTests.test_gdb_hardlink_debug
> 
> II) reproduce it manually
> 1) add meta-selftest to bblayers.conf
> 2) IMAGE_INSTALL_append = " selftest-hardlink selftest-hardlink-dbg
> selftest-hardlink-gdb"
> 3) bitbake core-image-minimal
> 4) On target:
>      gdb /usr/bin/hello1
>      (gdb) b main

I confirmed I could also reproduce it. We've just been lucky with the
configuration the autobuilder tests. 

I think we need to improve the test case. Does installing the libc
headers/dev package so that stdio2.h is there help?

Cheers,

Richard