static char *tp_from_combined_area(const struct tls_info *info,
void *combined_area, size_t tdb_size) {
size_t tls_size = info->tdata_size + info->tbss_size;
ptrdiff_t tdboff = __nacl_tp_tdb_offset(tdb_size);
if (tdboff < 0) {
/*
* The combined area is big enough to hold the TDB and then be aligned
* up to the $tp alignment requirement. If the whole area is aligned
* to the $tp requirement, then aligning the beginning of the area
* would give us the beginning unchanged, which is not what we need.
* Instead, align from the putative end of the TDB, to decide where
* $tp--the true end of the TDB--should actually lie.
*/
return aligned_addr((char *) combined_area + tdb_size, info->tls_alignment);
} else {
/*
* The linker increases the size of the TLS block up to its alignment
* requirement, and that total is subtracted from the $tp address to
* access the TLS area. To keep that final address properly aligned,
* we need to align up from the allocated space and then add the
* aligned size.
*/
tls_size = aligned_size(tls_size, info->tls_alignment);
return aligned_addr((char *) combined_area, info->tls_alignment) + tls_size;
}
}
int
is_addr_aligned(
vmi_instance_t vmi,
addr_t addr)
{
return (addr == aligned_addr(vmi, addr));
}
void *__nacl_tls_data_bss_initialize_from_template(void *combined_area,
size_t tdb_size) {
if (__nacl_tp_tdb_offset(tdb_size) != 0) {
/*
* This needs more work for ARM.
* For now abort via null pointer dereference.
*/
while (1) *(volatile int *) 0;
} else {
void *tdb = aligned_addr(((char *) combined_area) + tls_size +
SAFETY_PADDING , tls_align);
return _dl_allocate_tls(tdb);
}
}
