Re: [PATCH v2 03/14] elf: Fix comments and logic in _dl_add_to_slotinfo

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 13/04/2021 05:18, Szabolcs Nagy via Libc-alpha wrote:
> Since
> 
>   commit a509eb117fac1d764b15eba64993f4bdb63d7f3c
>   Avoid late dlopen failure due to scope, TLS slotinfo updates [BZ #25112]
> 
> the generation counter update is not needed in the failure path.
> That commit ensures allocation in _dl_add_to_slotinfo happens before
> the demarcation point in dlopen (it is called twice, first time is for
> allocation only where dlopen can still be reverted on failure, then
> second time actual dtv updates are done which then cannot fail).


LGTM, the commit is more clear now.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> 
> --
> v2:
> - expanded the commit message a bit.
> ---
>  elf/dl-tls.c | 11 +----------
>  1 file changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/elf/dl-tls.c b/elf/dl-tls.c
> index 79b93ad91b..24d00c14ef 100644
> --- a/elf/dl-tls.c
> +++ b/elf/dl-tls.c
> @@ -998,16 +998,7 @@ _dl_add_to_slotinfo (struct link_map *l, bool do_add)
>  		+ TLS_SLOTINFO_SURPLUS * sizeof (struct dtv_slotinfo));
>        if (listp == NULL)
>  	{
> -	  /* We ran out of memory.  We will simply fail this
> -	     call but don't undo anything we did so far.  The
> -	     application will crash or be terminated anyway very
> -	     soon.  */
> -
> -	  /* We have to do this since some entries in the dtv
> -	     slotinfo array might already point to this
> -	     generation.  */
> -	  ++GL(dl_tls_generation);
> -
> +	  /* We ran out of memory while resizing the dtv slotinfo list.  */
>  	  _dl_signal_error (ENOMEM, "dlopen", NULL, N_("\
>  cannot create TLS data structures"));
>  	}
>