This fixes PR36927.
The issue is next. Imagine we have -Ttext 0x7c and code below.
.code16
.global _start
_start:
movb $_start+0x83,%ah
So we have R_386_8 relocation and _start at 0x7C.
Addend is 0x83 == 131. We will sign extend it to 0xffffffffffffff83.
Now, 0xffffffffffffff83 + 0x7c gives us 0xFFFFFFFFFFFFFFFF.
Techically 0x83 + 0x7c == 0xFF, we do not exceed 1 byte value, but
currently LLD errors out, because we use checkUInt<8>.
Let's try to use checkInt<8> now and the following code to see if it can help (no):
main.s:
.byte foo
input.s:
.globl foo
.hidden foo
foo = 0xff
Here, foo is 0xFF. And addend is 0x0. Final value is 0x00000000000000FF.
Again, it fits one byte well, but with checkInt<8>,
we would error out it, so we can't use it.
What we want to do is to check that the result fits 1 byte well.
Patch changes the check to checkIntUInt to fix the issue.
Differential revision: https://reviews.llvm.org/D45051
llvm-svn: 329061
// R_386_{PC,}{8,16} are not part of the i386 psABI, but they are
// being used for some 16-bit programs such as boot loaders, so
// we want to support them.
- checkUInt(Loc, Val, 8, Type);
+ checkIntUInt(Loc, Val, 8, Type);
*Loc = Val;
break;
case R_386_PC8:
*Loc = Val;
break;
case R_386_16:
- checkUInt(Loc, Val, 16, Type);
+ checkIntUInt(Loc, Val, 16, Type);
write16le(Loc, Val);
break;
case R_386_PC16:
--- /dev/null
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=i386-pc-linux %s -o %t
+# RUN: ld.lld -Ttext 0x7c00 %t -o %t2
+# RUN: llvm-objdump -s %t2 | FileCheck %s
+
+# CHECK: Contents of section .text:
+# CHECK-NEXT: 7c00 b800ff
+
+.code16
+.global _start
+_start:
+ movw $_start+0x8300,%ax
// CHECK-NEXT: 1000 42
// RUN: not ld.lld -shared %t %t2 -o %t4 2>&1 | FileCheck --check-prefix=ERROR %s
-// ERROR: relocation R_386_16 out of range: 65536 is not in [0, 65535]
+// ERROR: relocation R_386_16 out of range: 65536 is not in [-32768, 32767]
.short foo
--- /dev/null
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=i386-pc-linux %s -o %t
+# RUN: ld.lld -Ttext 0x7c %t -o %t2
+# RUN: llvm-objdump -s %t2 | FileCheck %s
+
+# CHECK: Contents of section .text:
+# CHECK-NEXT: 007c b4ff
+
+.code16
+.global _start
+_start:
+ movb $_start+0x83,%ah
// CHECK-NEXT: 1000 ff
// RUN: not ld.lld -shared %t %t2 -o %t4 2>&1 | FileCheck --check-prefix=ERROR %s
-// ERROR: relocation R_386_8 out of range: 256 is not in [0, 255]
+// ERROR: relocation R_386_8 out of range: 256 is not in [-128, 127]
.byte foo