[AArch64] Relax TLS local dynamic traditional into local executable

The linker relaxation logic will be:

Code sequence I (tiny):

    0x00 adr  x0, :tlsldm:x
    0x04 bl   __tls_get_addr
         |
         V
    0x00 mrs  x0, tpidr_el0
    0x04 add  x0, x0, TCB_SIZE

Code sequence II (small):

    0x00 adrp a0, :tlsldm:x
    0x04 add  a0, #:tlsldm_lo12:x
    0x08 bl   __tls_get_addr
         |
         V
    0x00 mrs  x0, tpidr_el0
    0x04 add  x0, x0, TCB_SIZE
    0x08 nop

2015-09-09  Jiong Wang  <jiong.wang@arm.com>

bfd/
  * elfnn-aarch64.c (aarch64_tls_transition_without_check): Support
  three TLS local dynamic traditional relocations types.
  (elfNN_aarch64_tls_relax): Support TLS local dynamic traditional to
  local executable relaxation.

ld/testsuite/
  * ld-aarch64/tls-relax-ld-le-tiny.s: New testcase.
  * ld-aarch64/tls-relax-ld-le-small.s: Likewise.
  * ld-aarch64/tls-relax-ld-le-tiny.d: New expectation file.
  * ld-aarch64/tls-relax-ld-le-small.d: Likewise.
  * ld-aarch64/aarch64-elf.exp: Run new testcases.
This commit is contained in:
Jiong Wang 2015-09-09 14:19:28 +01:00
parent d660d56578
commit 259364adb8
8 changed files with 148 additions and 0 deletions

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@ -1,3 +1,10 @@
2015-09-09 Jiong Wang <jiong.wang@arm.com>
* elfnn-aarch64.c (aarch64_tls_transition_without_check): Support three
TLS local dynamic traditional relocations types.
(elfNN_aarch64_tls_relax): Support TLS local dynamic traditional to
local executable relaxation.
2015-09-03 H.J. Lu <hongjiu.lu@intel.com>
* elf64-x86-64.c (elf_x86_64_convert_mov_to_lea): Remove

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@ -213,6 +213,9 @@
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSIE_LD_GOTTPREL_PREL19 \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSIE_LDNN_GOTTPREL_LO12_NC \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSLD_ADD_LO12_NC \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSLD_ADR_PAGE21 \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSLD_ADR_PREL21 \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSDESC_ADR_PAGE21 \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSDESC_ADR_PREL21 \
|| (R_TYPE) == BFD_RELOC_AARCH64_TLSDESC_LD_PREL19 \
@ -4390,6 +4393,11 @@ aarch64_tls_transition_without_check (bfd_reloc_code_real_type r_type,
/* Instructions with these relocations will become NOPs. */
return BFD_RELOC_AARCH64_NONE;
case BFD_RELOC_AARCH64_TLSLD_ADD_LO12_NC:
case BFD_RELOC_AARCH64_TLSLD_ADR_PAGE21:
case BFD_RELOC_AARCH64_TLSLD_ADR_PREL21:
return is_local ? BFD_RELOC_AARCH64_NONE : r_type;
default:
break;
}
@ -5616,6 +5624,51 @@ elfNN_aarch64_tls_relax (struct elf_aarch64_link_hash_table *globals,
}
return bfd_reloc_continue;
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
*/
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);
bfd_putl32 (0xd53bd040, contents + rel->r_offset + 0);
bfd_putl32 (0x91004000, contents + rel->r_offset + 4);
return bfd_reloc_ok;
}
return bfd_reloc_continue;
case BFD_RELOC_AARCH64_TLSLD_ADR_PAGE21:
/* LD->LE relaxation (small):
adrp x0, :tlsldm:x => mrs x0, tpidr_el0
*/
if (is_local)
{
bfd_putl32 (0xd53bd040, contents + rel->r_offset);
return bfd_reloc_ok;
}
return bfd_reloc_continue;
case BFD_RELOC_AARCH64_TLSLD_ADD_LO12_NC:
/* LD->LE relaxation (small):
add x0, #:tlsldm_lo12:x => add x0, x0, TCB_SIZE
bl __tls_get_addr => nop
*/
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);
bfd_putl32 (0x91004000, contents + rel->r_offset + 0);
bfd_putl32 (0xd503201f, contents + rel->r_offset + 4);
return bfd_reloc_ok;
}
return bfd_reloc_continue;
default:
return bfd_reloc_continue;
}

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@ -1,3 +1,11 @@
2015-09-09 Jiong Wang <jiong.wang@arm.com>
* ld-aarch64/tls-relax-ld-le-tiny.s: New testcase.
* ld-aarch64/tls-relax-ld-le-small.s: Likewise.
* ld-aarch64/tls-relax-ld-le-tiny.d: New expectation file.
* ld-aarch64/tls-relax-ld-le-small.d: Likewise.
* ld-aarch64/aarch64-elf.exp: Run new testcases.
2015-09-07 Andrew Burgess <andrew.burgess@embecosm.com>
* ld-elf/orphan-7.map: Allow for other discarded sections.

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@ -178,6 +178,8 @@ run_dump_test "tls-relax-gdesc-le"
run_dump_test "tls-relax-gd-ie"
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-tiny"
run_dump_test "tls-desc-ie"
run_dump_test "tls-relax-gdesc-ie-2"
run_dump_test "tls-relax-gdesc-le-2"

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@ -0,0 +1,13 @@
#source: tls-relax-ld-le-small.s
#ld: -T relocs.ld -e0
#objdump: -dr
#...
+10000: 910003fd mov x29, sp
+10004: d53bd040 mrs x0, tpidr_el0
+10008: 91004000 add x0, x0, #0x10
+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

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@ -0,0 +1,27 @@
.cpu generic+fp+simd
.section .text.startup,"ax",%progbits
.align 2
.p2align 3,,7
.global main
.type main, %function
main:
add x29, sp, 0
adrp x0, :tlsldm:global_a0
add x0, x0, #:tlsldm_lo12_nc:global_a0
bl __tls_get_addr
nop
add x1, x0, #:dtprel_hi12:global_a0, lsl #12
add x1, x1, #:dtprel_lo12_nc:global_a0
adrp x0, .LC0
ret
.size main, .-main
.section .rodata.str1.8,"aMS",%progbits,1
.align 3
.LC0:
.string "Hello world %d\n"
.section .tdata,"awT",%progbits
.align 2
.type global_a0, %object
.size global_a0, 4
global_a0:
.word 16

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@ -0,0 +1,12 @@
#source: tls-relax-ld-le-tiny.s
#ld: -T relocs.ld -e0
#objdump: -dr
#...
+10000: 910003fd mov x29, sp
+10004: d53bd040 mrs x0, tpidr_el0
+10008: 91004000 add x0, x0, #0x10
+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

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@ -0,0 +1,26 @@
.cpu generic+fp+simd
.section .text.startup,"ax",%progbits
.align 2
.p2align 3,,7
.global main
.type main, %function
main:
add x29, sp, 0
adr x0, :tlsldm:global_a0
bl __tls_get_addr
nop
add x1, x0, #:dtprel_hi12:global_a0, lsl #12
add x1, x1, #:dtprel_lo12_nc:global_a0
adrp x0, .LC0
ret
.size main, .-main
.section .rodata.str1.8,"aMS",%progbits,1
.align 3
.LC0:
.string "Hello world %d\n"
.section .tdata,"awT",%progbits
.align 2
.type global_a0, %object
.size global_a0, 4
global_a0:
.word 16