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ld: aarch64: fix TLS relaxation where TCB_SIZE is used 

TCB_SIZE is 2*sizeof(void *), which is 0x10 for lp64, and 0x8 for
ilp32. During relaxation, ld goes to do a replace:
bl   __tls_get_addr => add R0, R0, TCB_SIZE

But actual implementation is:
bfd_putl32 (0x91004000, contents + rel->r_offset + 4);

Which is equivalent of add x0, x0, 0x10. This is wrong for ilp32.

The possible fix for it is:
bfd_putl32 (0x91000000 | (TCB_SIZE<<10), contents + rel->r_offset + 4);

But ilp32 also needs w-registers, so it's simpler to put proper
instruction in #if/#else condition.

There are 2 such relaxations in elfNN_aarch64_tls_relax(), and so 2 new
tests added for ilp32 mode to test it.

Yury

	* bfd/elfnn-aarch64.c: fix TLS relaxations for ilp32 where
	TCB_SIZE is used.
	* ld/testsuite/ld-aarch64/aarch64-elf.exp: Add tests for the case.
	* ld/testsuite/ld-aarch64/tls-relax-ld-le-small-ilp32.d: New file.
	* ld/testsuite/ld-aarch64/tls-relax-ld-le-tiny-ilp32.d: New file.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
This commit is contained in:
Yury Norov 2016-12-03 18:50:43 +05:30
parent 7acd51d697
commit c1fc2d7ee5
6 changed files with 56 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
bfd/ChangeLog
View File

@ -1,3 +1,8 @@
2016-12-14 Yury Norov <ynorov@caviumnetworks.com>
* bfd/elfnn-aarch64.c: fix TLS relaxations for ilp32 where
TCB_SIZE is used.
2016-12-13 Alan Modra <amodra@gmail.com>
* elf64-hppa.c (elf64_hppa_modify_segment_map): Don't add PHDR

20
bfd/elfnn-aarch64.c
View File

@ -5951,8 +5951,9 @@ elfNN_aarch64_tls_relax (struct elf_aarch64_link_hash_table *globals,
case BFD_RELOC_AARCH64_TLSLD_ADR_PREL21:
/* LD->LE relaxation (tiny):
adr x0, :tlsldm:x => mrs x0, tpidr_el0
bl __tls_get_addr => add x0, x0, TCB_SIZE
*/
bl __tls_get_addr => add R0, R0, TCB_SIZE
Where R is x for lp64 mode, and w for ilp32 mode. */
if (is_local)
{
BFD_ASSERT (rel->r_offset + 4 == rel[1].r_offset);
@ -5960,7 +5961,11 @@ elfNN_aarch64_tls_relax (struct elf_aarch64_link_hash_table *globals,
/* No need of CALL26 relocation for tls_get_addr. */
rel[1].r_info = ELFNN_R_INFO (STN_UNDEF, R_AARCH64_NONE);
bfd_putl32 (0xd53bd040, contents + rel->r_offset + 0);
#if ARCH_SIZE == 64
bfd_putl32 (0x91004000, contents + rel->r_offset + 4);
#else
bfd_putl32 (0x11002000, contents + rel->r_offset + 4);
#endif
return bfd_reloc_ok;
}
return bfd_reloc_continue;
@ -5978,17 +5983,22 @@ elfNN_aarch64_tls_relax (struct elf_aarch64_link_hash_table *globals,
case BFD_RELOC_AARCH64_TLSLD_ADD_LO12_NC:
/* LD->LE relaxation (small):
add x0, #:tlsldm_lo12:x => add x0, x0, TCB_SIZE
add x0, #:tlsldm_lo12:x => add R0, R0, TCB_SIZE
bl __tls_get_addr => nop
*/
Where R is x for lp64 mode, and w for ilp32 mode. */
if (is_local)
{
BFD_ASSERT (rel->r_offset + 4 == rel[1].r_offset);
BFD_ASSERT (ELFNN_R_TYPE (rel[1].r_info) == AARCH64_R (CALL26));
/* No need of CALL26 relocation for tls_get_addr. */
rel[1].r_info = ELFNN_R_INFO (STN_UNDEF, R_AARCH64_NONE);
#if ARCH_SIZE == 64
bfd_putl32 (0x91004000, contents + rel->r_offset + 0);
bfd_putl32 (0xd503201f, contents + rel->r_offset + 4);
#else
bfd_putl32 (0x11002000, contents + rel->r_offset + 0);
#endif
bfd_putl32 (INSN_NOP, contents + rel->r_offset + 4);
return bfd_reloc_ok;
}
return bfd_reloc_continue;

7
ld/ChangeLog
View File

@ -1,3 +1,10 @@
2016-12-14 Yury Norov <ynorov@caviumnetworks.com>
* ld/testsuite/ld-aarch64/aarch64-elf.exp: Add tests for tiny and
small ld-le relaxations in ilp32 mode.
* ld/testsuite/ld-aarch64/tls-relax-ld-le-small-ilp32.d: New file.
* ld/testsuite/ld-aarch64/tls-relax-ld-le-tiny-ilp32.d: New file.
2016-12-13 Jiong Wang <jiong.wang@arm.com>
* testsuite/ld-aarch64/aarch64-elf.exp (aarch64_choose_lp64_emul): New

2
ld/testsuite/ld-aarch64/aarch64-elf.exp
View File

@ -228,7 +228,9 @@ run_dump_test_lp64 "tls-relax-large-desc-le-be"
run_dump_test "tls-relax-gdesc-ie"
run_dump_test "tls-relax-ie-le"
run_dump_test "tls-relax-ld-le-small"
run_dump_test "tls-relax-ld-le-small-ilp32"
run_dump_test "tls-relax-ld-le-tiny"
run_dump_test "tls-relax-ld-le-tiny-ilp32"
run_dump_test "tls-desc-ie"
run_dump_test "tls-relax-gdesc-ie-2"
run_dump_test "tls-relax-gdesc-le-2"

14
ld/testsuite/ld-aarch64/tls-relax-ld-le-small-ilp32.d Normal file
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@ -0,0 +1,14 @@
#source: tls-relax-ld-le-small.s
#as: -mabi=ilp32
#ld: -m [aarch64_choose_ilp32_emul] -T relocs-ilp32.ld -e0
#objdump: -dr
#...
+10000: 910003fd mov x29, sp
+10004: d53bd040 mrs x0, tpidr_el0
+10008: 11002000 add w0, w0, #0x8
+1000c: d503201f nop
+10010: d503201f nop
+10014: 91400001 add x1, x0, #0x0, lsl #12
+10018: 91000021 add x1, x1, #0x0
+1001c: 90000000 adrp x0, 10000 <.*>
+10020: d65f03c0 ret

13
ld/testsuite/ld-aarch64/tls-relax-ld-le-tiny-ilp32.d Normal file
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@ -0,0 +1,13 @@
#source: tls-relax-ld-le-tiny.s
#as: -mabi=ilp32
#ld: -m [aarch64_choose_ilp32_emul] -T relocs-ilp32.ld -e0
#objdump: -dr
#...
+10000: 910003fd mov x29, sp
+10004: d53bd040 mrs x0, tpidr_el0
+10008: 11002000 add w0, w0, #0x8
+1000c: d503201f nop
+10010: 91400001 add x1, x0, #0x0, lsl #12
+10014: 91000021 add x1, x1, #0x0
+10018: 90000000 adrp x0, 10000 <main>
+1001c: d65f03c0 ret