Re: [PATCH 7/8] nptl: Add public rseq symbols and <sys/rseq.h>

[Florian Weimer <fweimer@redhat.com>]

* Szabolcs Nagy:

> The 12/07/2021 14:03, Florian Weimer via Libc-alpha wrote:
>> diff --git a/sysdeps/unix/sysv/linux/tst-rseq.c b/sysdeps/unix/sysv/linux/tst-rseq.c
>> index 926376b6a5..572c11166f 100644
>> --- a/sysdeps/unix/sysv/linux/tst-rseq.c
>> +++ b/sysdeps/unix/sysv/linux/tst-rseq.c
>> @@ -29,12 +29,20 @@
>>  # include <stdlib.h>
>>  # include <string.h>
>>  # include <syscall.h>
>> +# include <thread_pointer.h>
>> +# include <tls.h>
>>  # include "tst-rseq.h"
>>  
>>  static void
>>  do_rseq_main_test (void)
>>  {
>> +  struct pthread *pd = THREAD_SELF;
>> +
>>    TEST_VERIFY_EXIT (rseq_thread_registered ());
>> +  TEST_COMPARE (__rseq_flags, 0);
>> +  TEST_VERIFY ((char *) __thread_pointer () + __rseq_offset
>> +               == (char *) &pd->rseq_area);
>> +  TEST_COMPARE (__rseq_size, sizeof (pd->rseq_area));
>>  }
>
> sorry i just tested the committed patches on 32bit arm
> (on 64bit kernel) and there is a tls alignment issue
>
> FAIL: nptl/tst-tls3
> FAIL: nptl/tst-tls3-malloc
> FAIL: nptl/tst-tls5
>
> outputs:
>
> initial thread's struct pthread not aligned enough
> initial thread's struct pthread not aligned enough
> pthread_self () = 0xf7e2d350, size 1408, align 32, WRONG ALIGNMENT
>
> and rseq registration fails with EINVAL causing
>
> FAIL: misc/tst-rseq

I missed that we have both TCB_ALIGNMENT and TLS_TCB_ALIGN.
I think we need to remove the latter.  I will try to work on a patch
later today.

Thanks,
Florian