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

[Szabolcs Nagy]

The 04/22/2021 13:55, Florian Weimer wrote:
> * 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?

$ cat /proc/sys/kernel/yama/ptrace_scope
0

and the -static test passes so there gdb works.
i can reproduce it on all ubuntu setups i have.