Re: [PATCH] elf: Remove dead l_need_tls_init static-TLS init path

[Florian Weimer <fweimer@redhat.com>]

* Adhemerval Zanella Netto:

> On 09/06/26 11:13, Florian Weimer wrote:
>> * Adhemerval Zanella:
>> 
>>> @@ -671,16 +641,18 @@ dl_open_worker_begin (void *a)
>>>    if (mode & RTLD_GLOBAL)
>>>      add_to_global_resize (new);
>>>  
>>> -  /* Install the new modules in the DTV slotinfo and initialise their
>>> -     static TLS *before* relocation, so an IFUNC resolver firing during
>>> -     the relocation loop below can reach its DSO's __thread storage via
>>> -     __tls_get_addr / TLSDESC.  Without this, the resolver's TLS access
>>> -     for a just-loaded module would index into an unallocated DTV slot
>>> -     and crash.  If relocation later fails, the subsequent _dl_close_worker
>>> -     cleans up these slotinfo entries via remove_slotinfo.  */
>>> +  /* Register the new modules in the DTV slotinfo and bump the TLS
>>> +     generation counter *before* relocation, so an IFUNC resolver firing
>>> +     during the relocation loop below can reach its DSO's __thread storage
>>> +     via __tls_get_addr / TLSDESC.  Without this, the new module is not yet
>>> +     in GL(dl_tls_dtv_slotinfo_list), so the resolver's dynamic-TLS lookup
>>> +     fails to find it and faults.  The static-TLS image itself is copied
>>> +     lazily on first access; for the initial-exec model the static-TLS
>>> +     offset is reserved inline during relocation (see
>>> +     _dl_try_allocate_static_tls), not here.  If relocation later fails,
>>> +     the subsequent _dl_close_worker cleans up these slotinfo entries via
>>> +     remove_slotinfo.  */
>>>    if (any_tls)
>>> -    /* FIXME: This calls _dl_update_slotinfo, which aborts the process
>>> -       on memory allocation failure.  See bug 16134.  */
>>>      update_tls_slotinfo (new);
>> 
>> Is the FIXME truly gone?
> No, BZ 16134 is not fixed, only relocated. That lazy path still aborts:
>   
>   __tls_get_addr -> _dl_update_slotinfo -> _dl_resize_dtv -> oom
>
> Per:
>
> elf/dt-tls.c
>
>  921                   /* Resizing the dtv aborts on failure: bug 16134.  */
>  922                   dtv = _dl_resize_dtv (dtv, max_modid, THREAD_SELF);

Sorry, then why remove the comment?

Thanks,
Florian