[PATCH v3] nptl_db: Support different libpthread/ld.so load orders (bug 27744)

[Florian Weimer]

* Szabolcs Nagy:

> The 04/22/2021 10:05, Szabolcs Nagy via Gdb-patches wrote:
>> The 04/22/2021 10:33, Florian Weimer wrote:
>> > * Szabolcs Nagy:
>> > > on the aarch64 buildbot i see
>> > >
>> > > FAIL: nptl/tst-pthread-gdb-attach
>> > >
>> > > $ cat nptl/tst-pthread-gdb-attach.out
>> > > +set debug libthread-db 1
>> > > +add-symbol-file /work/glibc-aarch64-linux/build/build/nptl/tst-pthread-gdb-attach
>> > > add symbol table from file "/work/glibc-aarch64-linux/build/build/nptl/tst-pthread-gdb-attach"
>> > > +set auto-load safe-path /work/glibc-aarch64-linux/build/build/nptl_db
>> > > +set libthread-db-search-path /work/glibc-aarch64-linux/build/build/nptl_db
>> > > +attach 461328
>> > > [New LWP 461329]
>> > > Trying host libthread_db library: /work/glibc-aarch64-linux/build/build/nptl_db/libthread_db.so.1.
>> > > td_ta_new failed: application not linked with libthread
>> > > thread_db_load_search returning 0
>> > 
>> > Unfortunately I cannot reproduce this with binutils 2.30, GDB 8.2 and
>> > GCC 8.4.1.  Has your environment newer or older versions?
>> 
>> ubuntu flavour of
>> 
>> gcc 8.2.0
>> binutils 2.31.1
>> gdb 8.2
>> 
>> happens on armhf and aarch64 too.
>
> happens with gcc-10.2.0, gdb-9.2, binutils-2.34 too
> (still ubuntu)

Still no luck with binutils 2.35.1, a GCC 11 snapshot, and GDB 10.1.

Do you run this test as a regular user?  Could it be caused by YAMA
ptrace policies?

Thanks,
Florian