[ELF2/AArch64] Add support for R_AARCH64_CALL26 and R_AARCH64_JUMP26.

[ikudrin]

Summary

This patch covers only the case where no DSO is involved.

[davide]

ELF/Target.cpp

673

You can use or32le, no?

test/elf2/aarch64-relocs.s

62

Do you need the first nop?

[ruiu]

ELF/Target.cpp

669–672

I'd do this

if (!isInt<28>(X)) {
  if (Type == R_AARCH64_JUMP26)
    error("Relocation R_AARCH64_JUMP26 out of range");
  error("Relocation R_AARCH64_CALL26 out of range");
}

[ikudrin]

test/elf2/aarch64-relocs.s

62

It's just to make things a bit more interesting with a non-zero addend.

[davide]

Fine, looks good once you addressed other comments.

[ikudrin]

Thanks!

ELF/Target.cpp

void AArch64TargetInfo::relocateOne(uint8_t *Loc, uint8_t *BufEnd,
   }
   case R_AARCH64_ADR_PREL_PG_HI21: {
     uint64_t X = getAArch64Page(SA) - getAArch64Page(P);
     if (!isInt<33>(X))
       error("Relocation R_AARCH64_ADR_PREL_PG_HI21 out of range");
     updateAArch64Adr(Loc, (X >> 12) & 0x1FFFFF); // X[32:12]
     break;
   }
+  case R_AARCH64_JUMP26:
+  case R_AARCH64_CALL26: {
+    uint64_t X = SA - P;
+    if (!isInt<28>(X))
+      error(Twine("Relocation ") +
+            ((Type == R_AARCH64_CALL26) ? "R_AARCH64_CALL26"
+                                        : "R_AARCH64_JUMP26") +
+            " out of range");
+    write32le(Loc, read32le(Loc) | ((X & 0x0FFFFFFC) >> 2));
+    break;
+  }
   case R_AARCH64_LDST64_ABS_LO12_NC:
     // No overflow check needed.
     or32le(Loc, (SA & 0xFF8) << 7);
     break;
   case R_AARCH64_PREL16:
     if (!isInt<16>(SA))
       error("Relocation R_AARCH64_PREL16 out of range");
     write16le(Loc, SA - P);

test/elf2/aarch64-call26-error.s

+// RUN: llvm-mc -filetype=obj -triple=aarch64-pc-freebsd %S/Inputs/abs.s -o %tabs
+// RUN: llvm-mc -filetype=obj -triple=aarch64-pc-freebsd %s -o %t
+// RUN: not ld.lld2 -shared %t %tabs -o %t2 2>&1 | FileCheck %s
+// REQUIRES: aarch64
+
+.text
+    bl big
+
+// CHECK: R_AARCH64_CALL26 out of range

test/elf2/aarch64-jump26-error.s

+// RUN: llvm-mc -filetype=obj -triple=aarch64-pc-freebsd %S/Inputs/abs.s -o %tabs
+// RUN: llvm-mc -filetype=obj -triple=aarch64-pc-freebsd %s -o %t
+// RUN: not ld.lld2 -shared %t %tabs -o %t2 2>&1 | FileCheck %s
+// REQUIRES: aarch64
+
+.text
+    b big
+
+// CHECK: R_AARCH64_JUMP26 out of range

test/elf2/aarch64-relocs.s

foo:
   .size mystr, 3
 
 # S = 0x11024, A = 0x4
 # R = ((S + A) & 0xFFF) << 7 = 0x00001400
 # 0x00001400 | 0xf940177c = 0xf940177c
 # CHECK: Disassembly of section .R_AARCH64_LDST64_ABS_LO12_NC:
 # CHECK-NEXT: $x.6:
 # CHECK-NEXT:   11024:       7c 17 40 f9     ldr     x28, [x27, #40]
+
+.section .SUB,"ax",@progbits
+  nop
+sub:
+  nop
+
+# CHECK: Disassembly of section .SUB:
+# CHECK-NEXT: $x.8:
+# CHECK-NEXT:   1102c:       1f 20 03 d5     nop
+# CHECK: sub:
+# CHECK-NEXT:   11030:       1f 20 03 d5     nop
+
+.section .R_AARCH64_CALL26,"ax",@progbits
+call26:
+        bl sub
+
+# S = 0x1102c, A = 0x4, P = 0x11034
+# R = S + A - P = -0x4 = 0xfffffffc
+# (R & 0x0ffffffc) >> 2 = 0x03ffffff
+# 0x94000000 | 0x03ffffff = 0x97ffffff
+# CHECK: Disassembly of section .R_AARCH64_CALL26:
+# CHECK-NEXT: call26:
+# CHECK-NEXT:   11034:       ff ff ff 97     bl     #-4
+
+.section .R_AARCH64_JUMP26,"ax",@progbits
+jump26:
+        b sub
+
+# S = 0x1102c, A = 0x4, P = 0x11038
+# R = S + A - P = -0x8 = 0xfffffff8
+# (R & 0x0ffffffc) >> 2 = 0x03fffffe
+# 0x14000000 | 0x03fffffe = 0x17fffffe
+# CHECK: Disassembly of section .R_AARCH64_JUMP26:
+# CHECK-NEXT: jump26:
+# CHECK-NEXT:   11038:       fe ff ff 17     b      #-8