Support PPC64 ELFs (PS3); refactor relocation processing

Author: encounter

README.md

@@ -19,7 +19,7 @@ Supports:
 - ARM (GBA, DS, 3DS)
 - ARM64 (Switch)
 - MIPS (N64, PS1, PS2, PSP)
-- PowerPC (GameCube, Wii, Xbox 360)
+- PowerPC (GameCube, Wii, PS3, Xbox 360)
 - SuperH (Saturn, Dreamcast)
 - x86, x86_64 (PC)
 

objdiff-core/Cargo.toml

@@ -128,7 +128,7 @@ itertools = { version = "0.14", default-features = false, features = ["use_alloc
 log = { version = "0.4", default-features = false, optional = true }
 memmap2 = { version = "0.9", optional = true }
 num-traits = { version = "0.2", default-features = false, optional = true }
-object = { git = "https://github.com/gimli-rs/object", rev = "16ff70aa6fbd97d6bb7b92375929f4d72414c32b", default-features = false, features = ["read_core", "elf", "pe"] }
+object = { git = "https://github.com/gimli-rs/object", rev = "16ff70aa6fbd97d6bb7b92375929f4d72414c32b", default-features = false, features = ["read_core", "elf", "coff"] }
 pbjson = { version = "0.7", default-features = false, optional = true }
 prost = { version = "0.13", default-features = false, features = ["prost-derive"], optional = true }
 regex = { version = "1.11", default-features = false, features = [], optional = true }

objdiff-core/src/arch/arm.rs

@@ -11,7 +11,7 @@ use object::{Endian as _, Object as _, ObjectSection as _, ObjectSymbol as _, el
 use unarm::{args, arm, thumb};
 
 use crate::{
-    arch::Arch,
+    arch::{Arch, RelocationOverride, RelocationOverrideTarget},
     diff::{ArmArchVersion, ArmR9Usage, DiffObjConfig, display::InstructionPart},
     obj::{
         InstructionRef, Relocation, RelocationFlags, ResolvedInstructionRef, ResolvedRelocation,
@@ -356,47 +356,57 @@ impl Arch for ArchArm {
         Ok(())
     }
 
-    fn implcit_addend(
+    fn relocation_override(
         &self,
         _file: &object::File<'_>,
         section: &object::Section,
         address: u64,
-        _relocation: &object::Relocation,
-        flags: RelocationFlags,
-    ) -> Result<Option<i64>> {
-        let section_data = section.data()?;
-        let address = address as usize;
-        Ok(Some(match flags {
-            // ARM calls
-            RelocationFlags::Elf(elf::R_ARM_PC24)
-            | RelocationFlags::Elf(elf::R_ARM_XPC25)
-            | RelocationFlags::Elf(elf::R_ARM_CALL) => {
-                let data = section_data[address..address + 4].try_into()?;
-                let addend = self.endianness.read_i32_bytes(data);
-                let imm24 = addend & 0xffffff;
-                (imm24 << 2) << 8 >> 8
-            }
+        relocation: &object::Relocation,
+    ) -> Result<Option<RelocationOverride>> {
+        match relocation.flags() {
+            // Handle ELF implicit relocations
+            object::RelocationFlags::Elf { r_type } => {
+                if relocation.has_implicit_addend() {
+                    let section_data = section.data()?;
+                    let address = address as usize;
+                    let addend = match r_type {
+                        // ARM calls
+                        elf::R_ARM_PC24 | elf::R_ARM_XPC25 | elf::R_ARM_CALL => {
+                            let data = section_data[address..address + 4].try_into()?;
+                            let addend = self.endianness.read_i32_bytes(data);
+                            let imm24 = addend & 0xffffff;
+                            (imm24 << 2) << 8 >> 8
+                        }
 
-            // Thumb calls
-            RelocationFlags::Elf(elf::R_ARM_THM_PC22)
-            | RelocationFlags::Elf(elf::R_ARM_THM_XPC22) => {
-                let data = section_data[address..address + 2].try_into()?;
-                let high = self.endianness.read_i16_bytes(data) as i32;
-                let data = section_data[address + 2..address + 4].try_into()?;
-                let low = self.endianness.read_i16_bytes(data) as i32;
+                        // Thumb calls
+                        elf::R_ARM_THM_PC22 | elf::R_ARM_THM_XPC22 => {
+                            let data = section_data[address..address + 2].try_into()?;
+                            let high = self.endianness.read_i16_bytes(data) as i32;
+                            let data = section_data[address + 2..address + 4].try_into()?;
+                            let low = self.endianness.read_i16_bytes(data) as i32;
 
-                let imm22 = ((high & 0x7ff) << 11) | (low & 0x7ff);
-                (imm22 << 1) << 9 >> 9
-            }
+                            let imm22 = ((high & 0x7ff) << 11) | (low & 0x7ff);
+                            (imm22 << 1) << 9 >> 9
+                        }
 
-            // Data
-            RelocationFlags::Elf(elf::R_ARM_ABS32) => {
-                let data = section_data[address..address + 4].try_into()?;
-                self.endianness.read_i32_bytes(data)
-            }
+                        // Data
+                        elf::R_ARM_ABS32 => {
+                            let data = section_data[address..address + 4].try_into()?;
+                            self.endianness.read_i32_bytes(data)
+                        }
 
-            flags => bail!("Unsupported ARM implicit relocation {flags:?}"),
-        } as i64))
+                        flags => bail!("Unsupported ARM implicit relocation {flags:?}"),
+                    };
+                    Ok(Some(RelocationOverride {
+                        target: RelocationOverrideTarget::Keep,
+                        addend: addend as i64,
+                    }))
+                } else {
+                    Ok(None)
+                }
+            }
+            _ => Ok(None),
+        }
     }
 
     fn demangle(&self, name: &str) -> Option<String> {

objdiff-core/src/arch/arm64.rs

@@ -5,7 +5,7 @@ use alloc::{
 };
 use core::cmp::Ordering;
 
-use anyhow::{Result, bail};
+use anyhow::Result;
 use object::elf;
 use yaxpeax_arch::{Arch as YaxpeaxArch, Decoder, Reader, U8Reader};
 use yaxpeax_arm::armv8::a64::{
@@ -108,17 +108,6 @@ impl Arch for ArchArm64 {
         Ok(())
     }
 
-    fn implcit_addend(
-        &self,
-        _file: &object::File<'_>,
-        _section: &object::Section,
-        address: u64,
-        _relocation: &object::Relocation,
-        flags: RelocationFlags,
-    ) -> Result<Option<i64>> {
-        bail!("Unsupported ARM64 implicit relocation {:#x}:{:?}", address, flags)
-    }
-
     fn demangle(&self, name: &str) -> Option<String> {
         cpp_demangle::Symbol::new(name)
             .ok()

objdiff-core/src/arch/mips.rs

@@ -14,7 +14,7 @@ use rabbitizer::{
 };
 
 use crate::{
-    arch::Arch,
+    arch::{Arch, RelocationOverride, RelocationOverrideTarget},
     diff::{DiffObjConfig, MipsAbi, MipsInstrCategory, display::InstructionPart},
     obj::{
         InstructionArg, InstructionArgValue, InstructionRef, Relocation, RelocationFlags,
@@ -225,53 +225,67 @@ impl Arch for ArchMips {
         Ok(())
     }
 
-    fn implcit_addend(
+    fn relocation_override(
         &self,
         file: &object::File<'_>,
         section: &object::Section,
         address: u64,
-        reloc: &object::Relocation,
-        flags: RelocationFlags,
-    ) -> Result<Option<i64>> {
-        // Check for paired R_MIPS_HI16 and R_MIPS_LO16 relocations.
-        if let RelocationFlags::Elf(elf::R_MIPS_HI16 | elf::R_MIPS_LO16) = flags {
-            if let Some(addend) = self
-                .paired_relocations
-                .get(section.index().0)
-                .and_then(|m| m.get(&address).copied())
-            {
-                return Ok(Some(addend));
-            }
-        }
+        relocation: &object::Relocation,
+    ) -> Result<Option<RelocationOverride>> {
+        match relocation.flags() {
+            // Handle ELF implicit relocations
+            object::RelocationFlags::Elf { r_type } => {
+                if relocation.has_implicit_addend() {
+                    // Check for paired R_MIPS_HI16 and R_MIPS_LO16 relocations.
+                    if let elf::R_MIPS_HI16 | elf::R_MIPS_LO16 = r_type {
+                        if let Some(addend) = self
+                            .paired_relocations
+                            .get(section.index().0)
+                            .and_then(|m| m.get(&address).copied())
+                        {
+                            return Ok(Some(RelocationOverride {
+                                target: RelocationOverrideTarget::Keep,
+                                addend,
+                            }));
+                        }
+                    }
 
-        let data = section.data()?;
-        let code = data[address as usize..address as usize + 4].try_into()?;
-        let addend = self.endianness.read_u32_bytes(code);
-        Ok(Some(match flags {
-            RelocationFlags::Elf(elf::R_MIPS_32) => addend as i64,
-            RelocationFlags::Elf(elf::R_MIPS_26) => ((addend & 0x03FFFFFF) << 2) as i64,
-            RelocationFlags::Elf(elf::R_MIPS_HI16) => ((addend & 0x0000FFFF) << 16) as i32 as i64,
-            RelocationFlags::Elf(elf::R_MIPS_LO16 | elf::R_MIPS_GOT16 | elf::R_MIPS_CALL16) => {
-                (addend & 0x0000FFFF) as i16 as i64
-            }
-            RelocationFlags::Elf(elf::R_MIPS_GPREL16 | elf::R_MIPS_LITERAL) => {
-                let object::RelocationTarget::Symbol(idx) = reloc.target() else {
-                    bail!("Unsupported R_MIPS_GPREL16 relocation against a non-symbol");
-                };
-                let sym = file.symbol_by_index(idx)?;
+                    let data = section.data()?;
+                    let code = self
+                        .endianness
+                        .read_u32_bytes(data[address as usize..address as usize + 4].try_into()?);
+                    let addend = match r_type {
+                        elf::R_MIPS_32 => code as i64,
+                        elf::R_MIPS_26 => ((code & 0x03FFFFFF) << 2) as i64,
+                        elf::R_MIPS_HI16 => ((code & 0x0000FFFF) << 16) as i32 as i64,
+                        elf::R_MIPS_LO16 | elf::R_MIPS_GOT16 | elf::R_MIPS_CALL16 => {
+                            (code & 0x0000FFFF) as i16 as i64
+                        }
+                        elf::R_MIPS_GPREL16 | elf::R_MIPS_LITERAL => {
+                            let object::RelocationTarget::Symbol(idx) = relocation.target() else {
+                                bail!("Unsupported R_MIPS_GPREL16 relocation against a non-symbol");
+                            };
+                            let sym = file.symbol_by_index(idx)?;
 
-                // if the symbol we are relocating against is in a local section we need to add
-                // the ri_gp_value from .reginfo to the addend.
-                if sym.section().index().is_some() {
-                    ((addend & 0x0000FFFF) as i16 as i64) + self.ri_gp_value as i64
+                            // if the symbol we are relocating against is in a local section we need to add
+                            // the ri_gp_value from .reginfo to the addend.
+                            if sym.section().index().is_some() {
+                                ((code & 0x0000FFFF) as i16 as i64) + self.ri_gp_value as i64
+                            } else {
+                                (code & 0x0000FFFF) as i16 as i64
+                            }
+                        }
+                        elf::R_MIPS_PC16 => 0, // PC-relative relocation
+                        R_MIPS15_S3 => ((code & 0x001FFFC0) >> 3) as i64,
+                        flags => bail!("Unsupported MIPS implicit relocation {flags:?}"),
+                    };
+                    Ok(Some(RelocationOverride { target: RelocationOverrideTarget::Keep, addend }))
                 } else {
-                    (addend & 0x0000FFFF) as i16 as i64
+                    Ok(None)
                 }
             }
-            RelocationFlags::Elf(elf::R_MIPS_PC16) => 0, // PC-relative relocation
-            RelocationFlags::Elf(R_MIPS15_S3) => ((addend & 0x001FFFC0) >> 3) as i64,
-            flags => bail!("Unsupported MIPS implicit relocation {flags:?}"),
-        }))
+            _ => Ok(None),
+        }
     }
 
     fn demangle(&self, name: &str) -> Option<String> {

objdiff-core/src/arch/mod.rs

@@ -357,14 +357,15 @@ pub trait Arch: Send + Sync + Debug {
         None
     }
 
-    fn implcit_addend(
+    fn relocation_override(
         &self,
-        file: &object::File<'_>,
-        section: &object::Section,
-        address: u64,
-        relocation: &object::Relocation,
-        flags: RelocationFlags,
-    ) -> Result<Option<i64>>;
+        _file: &object::File<'_>,
+        _section: &object::Section,
+        _address: u64,
+        _relocation: &object::Relocation,
+    ) -> Result<Option<RelocationOverride>> {
+        Ok(None)
+    }
 
     fn demangle(&self, _name: &str) -> Option<String> { None }
 
@@ -411,7 +412,9 @@ pub fn new_arch(object: &object::File) -> Result<Box<dyn Arch>> {
     use object::Object as _;
     Ok(match object.architecture() {
         #[cfg(feature = "ppc")]
-        object::Architecture::PowerPc => Box::new(ppc::ArchPpc::new(object)?),
+        object::Architecture::PowerPc | object::Architecture::PowerPc64 => {
+            Box::new(ppc::ArchPpc::new(object)?)
+        }
         #[cfg(feature = "mips")]
         object::Architecture::Mips => Box::new(mips::ArchMips::new(object)?),
         #[cfg(feature = "x86")]
@@ -456,16 +459,17 @@ impl Arch for ArchDummy {
         Ok(())
     }
 
-    fn implcit_addend(
-        &self,
-        _file: &object::File<'_>,
-        _section: &object::Section,
-        _address: u64,
-        _relocation: &object::Relocation,
-        _flags: RelocationFlags,
-    ) -> Result<Option<i64>> {
-        Ok(Some(0))
-    }
-
     fn data_reloc_size(&self, _flags: RelocationFlags) -> usize { 0 }
 }
+
+pub enum RelocationOverrideTarget {
+    Keep,
+    Skip,
+    Symbol(object::SymbolIndex),
+    Section(object::SectionIndex),
+}
+
+pub struct RelocationOverride {
+    pub target: RelocationOverrideTarget,
+    pub addend: i64,
+}