https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102772
--- Comment #17 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to r...@cebitec.uni-bielefeld.de from comment #16)
> Same here:
>
> Program Headers:
> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
> [...]
> TLS 0x00c3d0 0x0806c3d0 0x00000000 0x00000 0x00024 RW 0x10
If both linkers reproduce the problem and the PT_TLS is 16-byte aligned
and thr.1 in it is at offset 0 (or multiple of 16), then I'd think that points
to the dynamic linker.
The TLS transitions are performed by the linker.
> > But the question is if in
> > struct __attribute__((aligned (32))) S { long long buf[4]; };
> > __thread struct S s;
> > S *foo (void) { return &s; }
> > it won't return not properly 32-byte aligned pointer too (and is that in all
> > threads or just some (initial vs. other threads)?
>
> I've wrapped that in a small test programming, calling foo both from the
> initial thread and a new one: in all cases, the return value from foo
> was 32-byte aligned as expected.
Perhaps the problem only shows when the PT_TLS size is not a multiple of the
alignment? Or depends on other PT_TLS segments in shared libraries in the same
process. The pointer2.f90 testcase will link against libgomp which uses TLS as
well.
So perhaps try:
struct __attribute__((aligned (16))) S { char buf[0x24]; };
__thread struct S s;
__attribute__((noipa)) S *foo (void) { return &s; }
int
main ()
{
#pragma omp parallel
__builtin_printf ("%p\n", foo ());
return 0;
}
?
