[lfs-dev] kernel messages during gcc tests

[William Harrington]

On Wed, February 3, 2016 04:36, Bruce Dubbs wrote:
> I just updated several packages in LFS and did a complete LFS build
> including all Chapter 6 tests.  One thing I noticed that I haven't seen
> before is a ton of error messages in /var/log/kern.log.  The look like:
>
> Feb  2 20:52:05 lfs78 kernel: [1888937.495544] lib-42.exe[6559]: segfault
> at 8 ip 00007f63a68c1fbe sp 00007fffd02bbde0 error 4 in
> libgomp.so.1.0.0[7f63a68ab000+1f000]
>
> In addition to segfaults, there are some messages about 'trap invalid
> opcode' in overflow-add-4.exe.
>
>  From the time stamps, I traced these to the gcc testuite.  The test log
> does not show anything unusual.  There are two unexpected failures in
> libstdc++:
>
> FAIL: experimental/filesystem/iterators/directory_iterator.cc
> FAIL: experimental/filesystem/iterators/recursive_directory_iterator.cc
>
> But I've seen those before.
>
> Overall the build seems to have been normal.
>
> A couple of things to consider is that it may be a HW issue on my system.
>   It's a new Skylake i5, so gcc may be making the wrong assumptions about
> instruction set.  I can check this out on an Haswell i7 to see if it
> happens there.
>
> Overall, these may just artifacts in the gcc test procedure, but has
> anyone else seen anything like this?
>
>
>    -- Bruce
Hello Bruce,

I haven't checked kernel messages during GCC testuite builds, but I have
noticed segfaults via kernel messages when testing GLIBC in the past. Did
you get any during the GLIBC tests, too?

I will usually run dmesg at the end of the build to see if anything
strange occurred throughout the build.

Sincerely,

William Harrington