Re: [PATCH] nptl: Add compiler barrier in nptl/tst-pthread-getattr

[Florian Weimer <fweimer at redhat dot com>]

* Carlos O'Donell:

>> tst-pthread-getattr.c: In function ‘allocate_and_test’:
>> tst-pthread-getattr.c:54:10: error: function returns address of local variable [-Werror=return-local-addr]
>>     54 |   return mem;
>>        |          ^~~
>> In file included from ../include/alloca.h:3,
>>                   from tst-pthread-getattr.c:26:
>> ../stdlib/alloca.h:35:23: note: declared here
>>     35 | # define alloca(size) __builtin_alloca (size)
>>        |                       ^~~~~~~~~~~~~~~~~~~~~~~
>> tst-pthread-getattr.c:51:9: note: in expansion of macro ‘alloca’
>>     51 |   mem = alloca ((size_t) (mem - target));
>>        |         ^~~~~~
>>
>> The address itself is used in a check in the caller, so using
>> uintptr_t instead is reasonable.
>
> Any reason why we wouldn't move the test into the function?

I think printf might fault because of its own stack usage (which can
easily exceed half a page in some cases).

Thanks,
Florian