aarch64: Use explicit offsets in _dl_tlsdesc_dynamic

Commit 389d1f1b232b3d6b9d73ee2c50e543ace6675621 (“Partial ILP32
support for aarch64”) broke dynamic TLS support because a load
offset changed:

 0000000000000030 <_dl_tlsdesc_dynamic>:
   30:  a9bc7bfd        stp     x29, x30, [sp,#-64]!
   34:  910003fd        mov     x29, sp
   38:  a9020be1        stp     x1, x2, [sp,#32]
   3c:  a90313e3        stp     x3, x4, [sp,#48]
   40:  d53bd044        mrs     x4, tpidr_el0
   44:  c8dffc1f        ldar    xzr, [x0]
   48:  f9400401        ldr     x1, [x0,#8]
   4c:  f9400080        ldr     x0, [x4]
   50:  f9400823        ldr     x3, [x1,#16]
   54:  f9400002        ldr     x2, [x0]
   58:  eb02007f        cmp     x3, x2
   5c:  540001a8        b.hi    90 <_dl_tlsdesc_dynamic+0x60>
   60:  f9400022        ldr     x2, [x1]
   64:  8b021000        add     x0, x0, x2, lsl #4
   68:  f9400000        ldr     x0, [x0]
   6c:  b100041f        cmn     x0, #0x1
   70:  54000100        b.eq    90 <_dl_tlsdesc_dynamic+0x60>
-  74:  f9400421        ldr     x1, [x1,#8]
+  74:  f9400821        ldr     x1, [x1,#16]
   78:  8b010000        add     x0, x0, x1
…

This commit introduces explicit struct offsets, generated
from the C headers, fixing the regression.

1 files changed, 7 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 1be316c..f75137b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2016-12-02  Florian Weimer  <fweimer@redhat.com>
+
+	* sysdeps/aarch64/tlsdesc.sym (TCBHEAD_DTV, DTV_COUNTER)
+	(TLS_DTV_UNALLOCATED): Add.
+	* sysdeps/aarch64/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Use explicit
+	offsets.
+
 2016-12-02  Stefan Liebler  <stli@linux.vnet.ibm.com>
 
 	* sysdeps/s390/fpu/libm-test-ulps: Regenerated.