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.

diff --git a/ChangeLog b/ChangeLog
index 1be316c0727bc2509f7b6b69f76527295e023df5..f75137bbea086036e15e0d8f730ea96a958705ab 100644 (file)
--- 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.

diff --git a/sysdeps/aarch64/dl-tlsdesc.S b/sysdeps/aarch64/dl-tlsdesc.S
index 42fa943859053d93e04d6c393cf67d9602bcf7d7..9e557dd1344eac72b8d6966f3763e0270f87f44e 100644 (file)
--- a/sysdeps/aarch64/dl-tlsdesc.S
+++ b/sysdeps/aarch64/dl-tlsdesc.S
@@ -154,7 +154,7 @@ _dl_tlsdesc_undefweak:
           _dl_tlsdesc_dynamic (struct tlsdesc *tdp)
           {
             struct tlsdesc_dynamic_arg *td = tdp->arg;
-            dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + DTV_OFFSET);
+            dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + TCBHEAD_DTV);
             if (__builtin_expect (td->gen_count <= dtv[0].counter
                && (dtv[td->tlsinfo.ti_module].pointer.val
                    != TLS_DTV_UNALLOCATED),
@@ -193,18 +193,18 @@ _dl_tlsdesc_dynamic:
           td->entry in _dl_tlsdesc_resolve_rela_fixup ensuring that the load
           from [x0,#PTR_SIZE] here happens after the initialization of td->arg.  */
        ldar    PTR_REG (zr), [x0]
-       ldr     PTR_REG (1), [x0,#PTR_SIZE]
-       ldr     PTR_REG (0), [x4]
-       ldr     PTR_REG (3), [x1,#(PTR_SIZE * 2)]
-       ldr     PTR_REG (2), [x0]
+       ldr     PTR_REG (1), [x0,#TLSDESC_ARG]
+       ldr     PTR_REG (0), [x4,#TCBHEAD_DTV]
+       ldr     PTR_REG (3), [x1,#TLSDESC_GEN_COUNT]
+       ldr     PTR_REG (2), [x0,#DTV_COUNTER]
        cmp     PTR_REG (3), PTR_REG (2)
        b.hi    2f
-       ldr     PTR_REG (2), [x1]
+       ldr     PTR_REG (2), [x1,#TLSDESC_MODID]
        add     PTR_REG (0), PTR_REG (0), PTR_REG (2), lsl #(PTR_LOG_SIZE + 1)
-       ldr     PTR_REG (0), [x0]
-       cmn     x0, #0x1
+       ldr     PTR_REG (0), [x0] /* Load val member of DTV entry.  */
+       cmp     x0, #TLS_DTV_UNALLOCATED
        b.eq    2f
-       ldr     PTR_REG (1), [x1,#(PTR_SIZE * 2)]
+       ldr     PTR_REG (1), [x1,#TLSDESC_MODOFF]
        add     PTR_REG (0), PTR_REG (0), PTR_REG (1)
        sub     PTR_REG (0), PTR_REG (0), PTR_REG (4)
 1:

diff --git a/sysdeps/aarch64/tlsdesc.sym b/sysdeps/aarch64/tlsdesc.sym
index 63766af612ac880bbde9dba1228cd19d334bee8d..a06a71977959fd2cc744f0f396f593c6cca8e950 100644 (file)
--- a/sysdeps/aarch64/tlsdesc.sym
+++ b/sysdeps/aarch64/tlsdesc.sym
@@ -13,3 +13,6 @@ TLSDESC_ARG                   offsetof(struct tlsdesc, arg)
 TLSDESC_GEN_COUNT      offsetof(struct tlsdesc_dynamic_arg, gen_count)
 TLSDESC_MODID          offsetof(struct tlsdesc_dynamic_arg, tlsinfo.ti_module)
 TLSDESC_MODOFF         offsetof(struct tlsdesc_dynamic_arg, tlsinfo.ti_offset)
+TCBHEAD_DTV            offsetof(tcbhead_t, dtv)
+DTV_COUNTER            offsetof(dtv_t, counter)
+TLS_DTV_UNALLOCATED    TLS_DTV_UNALLOCATED