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aarch64: Use explicit offsets in _dl_tlsdesc_dynamic

Browse Source 
Commit 389d1f1b23 (“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.
This commit is contained in:
Florian Weimer 2016-12-02 16:52:57 +01:00
parent 8068094f6e
commit 67aae64512
3 changed files with 19 additions and 9 deletions
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7
ChangeLog
View File

@ -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.

18
sysdeps/aarch64/dl-tlsdesc.S
View File

@ -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:

3
sysdeps/aarch64/tlsdesc.sym
View File

@ -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