diff options
Diffstat (limited to 'vendor/object/src/read/macho/relocation.rs')
| -rw-r--r-- | vendor/object/src/read/macho/relocation.rs | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/vendor/object/src/read/macho/relocation.rs b/vendor/object/src/read/macho/relocation.rs new file mode 100644 index 0000000..709f1a4 --- /dev/null +++ b/vendor/object/src/read/macho/relocation.rs @@ -0,0 +1,158 @@ +use core::{fmt, slice}; + +use crate::endian::Endianness; +use crate::macho; +use crate::read::{ + ReadRef, Relocation, RelocationEncoding, RelocationKind, RelocationTarget, SectionIndex, + SymbolIndex, +}; + +use super::{MachHeader, MachOFile}; + +/// An iterator for the relocations in a [`MachOSection32`](super::MachOSection32). +pub type MachORelocationIterator32<'data, 'file, Endian = Endianness, R = &'data [u8]> = + MachORelocationIterator<'data, 'file, macho::MachHeader32<Endian>, R>; +/// An iterator for the relocations in a [`MachOSection64`](super::MachOSection64). +pub type MachORelocationIterator64<'data, 'file, Endian = Endianness, R = &'data [u8]> = + MachORelocationIterator<'data, 'file, macho::MachHeader64<Endian>, R>; + +/// An iterator for the relocations in a [`MachOSection`](super::MachOSection). +pub struct MachORelocationIterator<'data, 'file, Mach, R = &'data [u8]> +where + Mach: MachHeader, + R: ReadRef<'data>, +{ + pub(super) file: &'file MachOFile<'data, Mach, R>, + pub(super) relocations: slice::Iter<'data, macho::Relocation<Mach::Endian>>, +} + +impl<'data, 'file, Mach, R> Iterator for MachORelocationIterator<'data, 'file, Mach, R> +where + Mach: MachHeader, + R: ReadRef<'data>, +{ + 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; + let cputype = self.file.header.cputype(endian); + if reloc.r_scattered(endian, cputype) { + // FIXME: handle scattered relocations + // We need to add `RelocationTarget::Address` for this. + continue; + } + let reloc = reloc.info(self.file.endian); + let mut encoding = RelocationEncoding::Generic; + let kind = match cputype { + macho::CPU_TYPE_ARM => match (reloc.r_type, reloc.r_pcrel) { + (macho::ARM_RELOC_VANILLA, false) => RelocationKind::Absolute, + _ => RelocationKind::MachO { + value: reloc.r_type, + relative: reloc.r_pcrel, + }, + }, + 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, + }, + } + } + macho::CPU_TYPE_X86 => match (reloc.r_type, reloc.r_pcrel) { + (macho::GENERIC_RELOC_VANILLA, false) => RelocationKind::Absolute, + _ => RelocationKind::MachO { + value: reloc.r_type, + relative: reloc.r_pcrel, + }, + }, + macho::CPU_TYPE_X86_64 => match (reloc.r_type, reloc.r_pcrel) { + (macho::X86_64_RELOC_UNSIGNED, false) => RelocationKind::Absolute, + (macho::X86_64_RELOC_SIGNED, true) => { + encoding = RelocationEncoding::X86RipRelative; + RelocationKind::Relative + } + (macho::X86_64_RELOC_BRANCH, true) => { + encoding = RelocationEncoding::X86Branch; + RelocationKind::Relative + } + (macho::X86_64_RELOC_GOT, true) => RelocationKind::GotRelative, + (macho::X86_64_RELOC_GOT_LOAD, true) => { + encoding = RelocationEncoding::X86RipRelativeMovq; + RelocationKind::GotRelative + } + _ => RelocationKind::MachO { + value: reloc.r_type, + relative: reloc.r_pcrel, + }, + }, + _ => RelocationKind::MachO { + value: reloc.r_type, + relative: reloc.r_pcrel, + }, + }; + let size = 8 << reloc.r_length; + let target = if reloc.r_extern { + RelocationTarget::Symbol(SymbolIndex(reloc.r_symbolnum as usize)) + } else { + RelocationTarget::Section(SectionIndex(reloc.r_symbolnum as usize)) + }; + 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 + // PC being different from the place of the relocation. + // This differs from other file formats, so adjust the + // addend here to account for this. + match cputype { + macho::CPU_TYPE_X86 => { + addend -= 1 << reloc.r_length; + } + macho::CPU_TYPE_X86_64 => { + addend -= 1 << reloc.r_length; + match reloc.r_type { + macho::X86_64_RELOC_SIGNED_1 => addend -= 1, + macho::X86_64_RELOC_SIGNED_2 => addend -= 2, + macho::X86_64_RELOC_SIGNED_4 => addend -= 4, + _ => {} + } + } + // TODO: maybe missing support for some architectures and relocations + _ => {} + } + } + return Some(( + reloc.r_address as u64, + Relocation { + kind, + encoding, + size, + target, + addend, + implicit_addend, + }, + )); + } + } +} + +impl<'data, 'file, Mach, R> fmt::Debug for MachORelocationIterator<'data, 'file, Mach, R> +where + Mach: MachHeader, + R: ReadRef<'data>, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("MachORelocationIterator").finish() + } +} |