[RFC][PATCH v12 7/8] Restore separate libc loading for the TLS/namespace storage test

[Adhemerval Zanella]

On 08/07/2021 13:32, Vivek Das Mohapatra via Libc-alpha wrote:
> tst-tls-ie-dlmopen checks to see that new namespaces consume
> TLS memory as expected: This does not happen when new namespaces
> share the same libc instance (since TLS is allocated only when
> a new libc instance insitialises its threading infrastructure).
> 
> Adding RTLD_ISOLATE to the dlmopen flags in the test restores
> the old behaviour which allows the test to check what it
> actually needs to.

LGTM, but this patch should be merged with the
'Implement dlmopen RTLD_SHARED flag (bug 22745)' one to be logically
consistent.

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

> ---
>  elf/tst-tls-ie-dlmopen.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/elf/tst-tls-ie-dlmopen.c b/elf/tst-tls-ie-dlmopen.c
> index a579d72d2d..e67017db2d 100644
> --- a/elf/tst-tls-ie-dlmopen.c
> +++ b/elf/tst-tls-ie-dlmopen.c
> @@ -53,7 +53,7 @@ static void *
>  load_and_access (Lmid_t lmid, const char *mod, const char *func)
>  {
>    /* Load module with TLS.  */
> -  void *p = xdlmopen (lmid, mod, RTLD_NOW);
> +  void *p = xdlmopen (lmid, mod, RTLD_NOW|RTLD_ISOLATE);
>    /* Access the TLS variable to ensure it is allocated.  */
>    void (*f) (void) = (void (*) (void))xdlsym (p, func);
>    f ();
> @@ -95,7 +95,7 @@ do_test (void)
>       than 1024 bytes are available (exact number depends on TLS optimizations
>       and the libc TLS use).  */
>    printf ("The next dlmopen should fail...\n");
> -  void *p = dlmopen (LM_ID_BASE, "tst-tls-ie-mod4.so", RTLD_NOW);
> +  void *p = dlmopen (LM_ID_BASE, "tst-tls-ie-mod4.so", RTLD_NOW|RTLD_ISOLATE);
>    if (p != NULL)
>      FAIL_EXIT1 ("error: expected dlmopen to fail because there is "
>  		"not enough surplus static TLS.\n");
>