read/macho: handle ARM64_RELOC_ADDEND

gimli-rs · Oct 24, 2023 · df35618 · df35618
1 parent edd17a5
commit df35618
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Showing 2 changed files with 13 additions and 8 deletions.
diff --git a/crates/examples/testfiles/macho/reloc-aarch64.o.objdump b/crates/examples/testfiles/macho/reloc-aarch64.o.objdump
@@ -20,14 +20,11 @@ __text relocations
 (20, Relocation { kind: MachO { value: 8, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
 (1c, Relocation { kind: MachO { value: 6, relative: false }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
 (18, Relocation { kind: MachO { value: 5, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
-(14, Relocation { kind: MachO { value: a, relative: false }, encoding: Generic, size: 20, target: Section(SectionIndex(14)), addend: 0, implicit_addend: true })
-(14, Relocation { kind: MachO { value: 4, relative: false }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
-(10, Relocation { kind: MachO { value: a, relative: false }, encoding: Generic, size: 20, target: Section(SectionIndex(14)), addend: 0, implicit_addend: true })
-(10, Relocation { kind: MachO { value: 3, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
+(14, Relocation { kind: MachO { value: 4, relative: false }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 14, implicit_addend: false })
+(10, Relocation { kind: MachO { value: 3, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 14, implicit_addend: false })
 (c, Relocation { kind: MachO { value: 4, relative: false }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
 (8, Relocation { kind: MachO { value: 3, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
-(4, Relocation { kind: MachO { value: a, relative: false }, encoding: Generic, size: 20, target: Section(SectionIndex(14)), addend: 0, implicit_addend: true })
-(4, Relocation { kind: MachO { value: 2, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
+(4, Relocation { kind: MachO { value: 2, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 14, implicit_addend: false })
 (0, Relocation { kind: MachO { value: 2, relative: true }, encoding: Generic, size: 20, target: Symbol(SymbolIndex(3)), addend: 0, implicit_addend: true })
 
 __data relocations

diff --git a/src/read/macho/relocation.rs b/src/read/macho/relocation.rs
@@ -34,6 +34,7 @@ where
     type Item = (u64, Relocation);
 
     fn next(&mut self) -> Option<Self::Item> {
+        let mut paired_addend = 0;
         loop {
             let reloc = self.relocations.next()?;
             let endian = self.file.endian;
@@ -56,6 +57,12 @@ where
                 macho::CPU_TYPE_ARM64 | macho::CPU_TYPE_ARM64_32 => {
                     match (reloc.r_type, reloc.r_pcrel) {
                         (macho::ARM64_RELOC_UNSIGNED, false) => RelocationKind::Absolute,
+                        (macho::ARM64_RELOC_ADDEND, _) => {
+                            paired_addend = i64::from(reloc.r_symbolnum)
+                                .wrapping_shl(64 - 24)
+                                .wrapping_shr(64 - 24);
+                            continue;
+                        }
                         _ => RelocationKind::MachO {
                             value: reloc.r_type,
                             relative: reloc.r_pcrel,
@@ -100,7 +107,8 @@ where
             } else {
                 RelocationTarget::Section(SectionIndex(reloc.r_symbolnum as usize))
             };
-            let mut addend = 0;
+            let implicit_addend = paired_addend == 0;
+            let mut addend = paired_addend;
             if reloc.r_pcrel {
                 // For PC relative relocations on some architectures, the
                 // addend does not include the offset required due to the
@@ -132,7 +140,7 @@ where
                     size,
                     target,
                     addend,
-                    implicit_addend: true,
+                    implicit_addend,
                 },
             ));
         }