[ELF][AArch64] Support for movz, movk tprel relocations

This patch Implements the R_AARCH64_TLSLE_MOVW_TPREL_G*[_NC]. These are
logically the same calculation as the existing TLSLE relocations with
the result written back to mov[nz] and movk instructions. A typical code
sequence is:
movz x0, #:tprel_g2:foo    // bits [47:32] of R_TLS with overflow check
movk x0, #:tprel_g1_nc:foo // bits [31:16] of R_TLS with no overflow check
movk x0, #:tprel_g0_nc:foo // bits [15:0] of R_TLS with no overflow check

This type of code sequence is usually used with a large code model.

Differential Revision: https://reviews.llvm.org/D65882

Fixes: PR42853
llvm-svn: 368293
This commit is contained in:
Peter Smith 2019-08-08 13:38:09 +00:00
parent 59fabf9c60
commit d4695e1d75
3 changed files with 94 additions and 0 deletions

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@ -90,6 +90,11 @@ RelExpr AArch64::getRelExpr(RelType type, const Symbol &s,
case R_AARCH64_TLSLE_LDST32_TPREL_LO12_NC:
case R_AARCH64_TLSLE_LDST64_TPREL_LO12_NC:
case R_AARCH64_TLSLE_LDST128_TPREL_LO12_NC:
case R_AARCH64_TLSLE_MOVW_TPREL_G0:
case R_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
case R_AARCH64_TLSLE_MOVW_TPREL_G1:
case R_AARCH64_TLSLE_MOVW_TPREL_G1_NC:
case R_AARCH64_TLSLE_MOVW_TPREL_G2:
return R_TLS;
case R_AARCH64_CALL26:
case R_AARCH64_CONDBR19:
@ -376,20 +381,25 @@ void AArch64::relocateOne(uint8_t *loc, RelType type, uint64_t val) const {
break;
case R_AARCH64_MOVW_PREL_G0:
case R_AARCH64_MOVW_SABS_G0:
case R_AARCH64_TLSLE_MOVW_TPREL_G0:
checkInt(loc, val, 17, type);
LLVM_FALLTHROUGH;
case R_AARCH64_MOVW_PREL_G0_NC:
case R_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
writeSMovWImm(loc, val);
break;
case R_AARCH64_MOVW_PREL_G1:
case R_AARCH64_MOVW_SABS_G1:
case R_AARCH64_TLSLE_MOVW_TPREL_G1:
checkInt(loc, val, 33, type);
LLVM_FALLTHROUGH;
case R_AARCH64_MOVW_PREL_G1_NC:
case R_AARCH64_TLSLE_MOVW_TPREL_G1_NC:
writeSMovWImm(loc, val >> 16);
break;
case R_AARCH64_MOVW_PREL_G2:
case R_AARCH64_MOVW_SABS_G2:
case R_AARCH64_TLSLE_MOVW_TPREL_G2:
checkInt(loc, val, 49, type);
LLVM_FALLTHROUGH;
case R_AARCH64_MOVW_PREL_G2_NC:

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@ -34,3 +34,22 @@ movn x0, #:prel_g0:.-0x10001
movn x0, #:prel_g1:.-0x100010000
# CHECK: relocation R_AARCH64_MOVW_PREL_G2 out of range: -281479271677952 is not in [-281474976710656, 281474976710655]
movn x0, #:prel_g2:.-0x1000100000000
movz x0, #:tprel_g0: v1
# CHECK: relocation R_AARCH64_TLSLE_MOVW_TPREL_G0 out of range: 65552 is not in [-65536, 65535]
movz x0, #:tprel_g1: v2
# CHECK: relocation R_AARCH64_TLSLE_MOVW_TPREL_G1 out of range: 4295032848 is not in [-4294967296, 4294967295]
movz x0, #:tprel_g2: v3
# CHECK: relocation R_AARCH64_TLSLE_MOVW_TPREL_G2 out of range: 281479271743496 is not in [-281474976710656, 281474976710655]
.section .tbss,"awT",@nobits
.balign 16
.space 0x10000
v1:
.quad 0
.space 0x100000000 - 8
v2:
.quad 0
.space 0x1000000000000 - 16
v3:
.quad 0

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@ -0,0 +1,65 @@
# REQUIRES: aarch64
# RUN: llvm-mc -filetype=obj -triple=aarch64-linux-gnu %s -o %t.o
# RUN: ld.lld %t.o -o %t
# RUN: llvm-objdump -d %t
# RUN: llvm-readobj --symbols %t
# RUN: llvm-objdump --no-show-raw-insn -d %t | FileCheck %s
# RUN: llvm-readobj --symbols %t | FileCheck --check-prefix=CHECK-SYM %s
## Test the the local exec relocations that map to:
## R_AARCH64_TLSLE_MOVW_TPREL_G2
## R_AARCH64_TLSLE_MOVW_TPREL_G1
## R_AARCH64_TLSLE_MOVW_TPREL_G1_NC
## R_AARCH64_TLSLE_MOVW_TPREL_G0
## R_AARCH64_TLSLE_MOVW_TPREL_G0_NC
## They calculate the same value as the other TPREL relocations, namely the
## offset from the thread pointer TP. The G0, G1 and G2 refer to partitions
## of the result with G2 bits [47:32], G1 bits [31:16] and G0 bits [15:0]
## the NC variant does not check for overflow.
## In AArch64 the structure of the TLS at runtime is:
## | TCB | Alignment Padding | TLS Block |
## With TP pointing to the start of the TCB. All offsets will be positive.
.text
## Access variable in first partition
movz x0, #:tprel_g0:v0
## TCB + 0 == 16
# CHECK: mov x0, #16
# CHECK-SYM: Name: v0
# CHECK-SYM-NEXT: Value: 0x0
## Access variable in second partition
movz x0, #:tprel_g1:v1
movk x0, #:tprel_g0_nc:v1
## TCB + 65536 across movz and movk
# CHECK-NEXT: mov x0, #65536
# CHECK-NEXT: movk x0, #16
# CHECK-SYM: Name: v1
# CHECK-SYM-NEXT: Value: 0x10000
## Access variable in third partition
movz x0, #:tprel_g2:v2
movk x0, #:tprel_g1_nc:v2
movk x0, #:tprel_g0_nc:v2
## TCB + 65536 + 4294967296 across movz and 2 movk instructions
# CHECK-NEXT: mov x0, #4294967296
# CHECK-NEXT: movk x0, #1, lsl #16
# CHECK-NEXT: movk x0, #16
# CHECK-SYM: Name: v2
# CHECK-SYM-NEXT: Value: 0x100010000
.section .tbss,"awT",@nobits
.balign 16
v0:
.quad 0
.space 0x10000 - 8
v1:
.quad 0
.space 0x100000000 - 8
v2:
.quad 0