From c3fbd3ed22c2d5af02a637d4d9cb3732f0e125bc Mon Sep 17 00:00:00 2001 From: Ales Katona Date: Fri, 8 Jan 2021 22:38:23 -0800 Subject: [PATCH] WIP --- src/common/output.rs | 7 --- src/common/section.rs | 34 +++++-------- src/formats/elf/object.rs | 4 +- src/formats/elf/output.rs | 99 +++++++++++++++++++++----------------- src/formats/elf/segment.rs | 26 +++++----- src/linker.rs | 16 +----- 6 files changed, 80 insertions(+), 106 deletions(-) diff --git a/src/common/output.rs b/src/common/output.rs index 9e279b9..46532f7 100644 --- a/src/common/output.rs +++ b/src/common/output.rs @@ -4,8 +4,6 @@ use super::Section; use crate::error::Error; pub trait Output<'data> { - fn allocate(&mut self, size: u64) -> Result; - fn append_section(&mut self, section: Section<'data>) -> Result<(), Error>; // fn prepare_symbol(&mut self, symbol: impl Lazy) -> Result<&mut Self, Error>; @@ -16,11 +14,6 @@ pub trait Output<'data> { pub struct DummyOutput; impl<'data> Output<'data> for DummyOutput { - fn allocate(&mut self, size: u64) -> Result { - eprintln!("Allocating: {}", size); - Ok(size) - } - fn append_section(&mut self, section: Section<'data>) -> Result<(), Error> { eprintln!("Appending section: {}", section); Ok(()) diff --git a/src/common/section.rs b/src/common/section.rs index 47dbfaf..5cab17d 100644 --- a/src/common/section.rs +++ b/src/common/section.rs @@ -4,21 +4,22 @@ use std::{ fmt::{Display, Formatter}, }; -pub trait CBI<'data, T>: Iterator { - fn clone_to_box(&self) -> Box + 'data>; -} +// pub trait CBI<'data, T>: Iterator { +// fn clone_to_box(&self) -> Box + 'data>; +// } -impl<'data, T, X: 'data + Iterator + Clone> CBI<'data, T> for X { - fn clone_to_box(&self) -> Box + 'data> { - Box::new(self.clone()) - } -} +// impl<'data, T, X: 'data + Iterator + Clone> CBI<'data, T> for X { +// fn clone_to_box(&self) -> Box + 'data> { +// Box::new(self.clone()) +// } +// } -pub type SectionDataIterator<'data> = Box + 'data>; +// pub type SectionDataIterator<'data> = Box + 'data>; +#[derive(Clone)] pub struct SectionInfo<'data> { pub size: u64, - pub data: Option>, + pub data: Option<&'data [u8]>, pub offset: u64, } @@ -29,19 +30,6 @@ pub enum Section<'data> { Bss(SectionInfo<'data>), } -impl<'data> Clone for SectionInfo<'data> { - fn clone(&self) -> Self { - Self { - size: self.size, - data: match self.data.as_ref() { - Some(iter) => Some(iter.clone_to_box()), - None => None, - }, - offset: self.offset, - } - } -} - impl Section<'_> { pub fn size(&self) -> Result { match self { diff --git a/src/formats/elf/object.rs b/src/formats/elf/object.rs index 62b1ba4..1389f58 100644 --- a/src/formats/elf/object.rs +++ b/src/formats/elf/object.rs @@ -52,12 +52,12 @@ impl Relocatable for ElfObject { Type::ProgBits => { if s.header.sh_size > 0 { if let Some(di) = match &s.contents { - Contents64::Raw(v) => Some(v.iter()), + Contents64::Raw(v) => Some(v), _ => None, } { let si = SectionInfo { size: s.header.sh_size, - data: Some(Box::new(di.copied())), + data: Some(di), offset: s.header.sh_offset, }; let s_name: &str = &s.name; diff --git a/src/formats/elf/output.rs b/src/formats/elf/output.rs index cbc7e61..beb95c0 100644 --- a/src/formats/elf/output.rs +++ b/src/formats/elf/output.rs @@ -25,7 +25,7 @@ use super::ElfObject; pub struct ElfOutput<'data> { destination: PathBuf, file: ELF64, - segment_data: SegmentData<'data>, + input_data: InputData<'data>, } impl<'data> ElfOutput<'data> { @@ -44,7 +44,7 @@ impl<'data> ElfOutput<'data> { Self { destination, file: elf, - segment_data: SegmentData::new(), + input_data: InputData::new(), } } @@ -54,34 +54,32 @@ impl<'data> ElfOutput<'data> { Self { destination, file: elf_bin_from_object(other), - segment_data: SegmentData::new(), + input_data: InputData::new(), } } - fn populate_sections(&mut self) -> Result { + fn populate_sections(&mut self) -> Result<(), Error> { let mut names = Vec::new(); let mut name_idx = 0usize; - let mut result = 0u64; - for (name, sections) in self.segment_data.sections_mut() { - let mut data = Vec::new(); + for (name, sections) in self.input_data.sections_mut() { + let mut data_size = 0; - for t in sections.iter_mut() { - if let Some(iter) = &mut t.data { - data.extend(iter.as_mut()); + for t in sections.iter() { + if let Some(bytes) = t.data { + data_size += bytes.len(); } } - if data.is_empty() { + if data_size == 0{ continue; } - result += data.len() as u64; names.push(name); let section = Section64 { name: name.into(), - header: make_section_header(name_idx, ShType::ProgBits, data.len()), - contents: Contents64::Raw(data), + header: make_section_header(name_idx, ShType::ProgBits, data_size), + contents: Contents64::Raw(Vec::new()), // placeholder only }; name_idx += name.len() + 1; self.file.add_section(section); @@ -90,7 +88,6 @@ impl<'data> ElfOutput<'data> { let name = ".shstrtab"; names.push(name); let string_table = build_string_table(names, true); - result += string_table.len() as u64; let section = Section64 { name: name.into(), header: make_section_header(name_idx, ShType::StrTab, string_table.len()), @@ -98,7 +95,7 @@ impl<'data> ElfOutput<'data> { }; self.file.add_section(section); - Ok(result) + Ok(()) } fn populate_segment(&mut self, offset: &mut u64, size: u64, which: SegmentType) { @@ -114,12 +111,15 @@ impl<'data> ElfOutput<'data> { segment.header.p_memsz = size; segment.header.p_offset = *offset; + let mut page_size = next_page(size); + match which { SegmentType::Text => segment.header.p_flags = PF_R | PF_X, SegmentType::Data => segment.header.p_flags = PF_R | PF_W, SegmentType::Bss => { segment.header.p_flags = PF_R; segment.header.p_memsz = 0; + page_size = 0; } } @@ -127,7 +127,7 @@ impl<'data> ElfOutput<'data> { self.file.ehdr.e_phnum += 1; self.file.ehdr.e_phentsize = size_of::() as u16; - *offset += next_page(size); + *offset += page_size; } fn populate_segments(&mut self) -> Result { @@ -136,29 +136,25 @@ impl<'data> ElfOutput<'data> { // contains .text + .rodata as one segment self.populate_segment( &mut offset, - self.segment_data.program_size(), + self.input_data.program_size(), SegmentType::Text, ); // contains .data as one segment self.populate_segment( &mut offset, - self.segment_data.data_size(), + self.input_data.data_size(), SegmentType::Data, ); // contains .bss as one segment - self.populate_segment(&mut offset, self.segment_data.bss_size(), SegmentType::Bss); + self.populate_segment(&mut offset, self.input_data.bss_size(), SegmentType::Bss); Ok(offset) } } impl<'data> Output<'data> for ElfOutput<'data> { - fn allocate(&mut self, size: u64) -> Result { - Ok(size) - } - fn append_section(&mut self, section: Section<'data>) -> Result<(), Error> { - self.segment_data.append_section(section) + self.input_data.append_section(section) } fn finalize(mut self) -> Result { @@ -169,20 +165,19 @@ impl<'data> Output<'data> for ElfOutput<'data> { self.populate_sections()?; let page_size = self.populate_segments()?; + self.file.ehdr.e_shnum = self.file.sections.len() as u16; + self.file.ehdr.e_entry = 4096; // TODO self.file.ehdr.e_phentsize = PHS; self.file.ehdr.e_shentsize = SHS; - self.file.ehdr.e_phoff = EHS; // TODO: align - self.file.ehdr.e_shoff = self.file.ehdr.e_phoff - + u64::from(self.file.ehdr.e_phnum * self.file.ehdr.e_phentsize) - + page_size; - self.file.ehdr.e_shnum = self.file.sections.len() as u16; - self.file.ehdr.e_entry = 0x100; // TODO + self.file.ehdr.e_phoff = EHS; + self.file.ehdr.e_shoff = self.file.ehdr.e_phoff + (usize::from(self.file.ehdr.e_phentsize) * self.file.segments.len()) as u64; let str_path = expand_path(&self.destination)?; let mut writer = file_writer(str_path, 0o755)?; let mut offset = 0; + // write ELF header offset += writer.write(&self.file.ehdr.to_le_bytes())?; // write program header table @@ -191,17 +186,32 @@ impl<'data> Output<'data> for ElfOutput<'data> { offset += writer.write(&seg.header.to_le_bytes())?; } - // write section/segment data + eprintln!("SH start: {}", offset); + // write section header table for sec in self.file.sections.iter_mut() { - sec.header.sh_offset = offset as u64; - offset += write_padded(&mut writer, offset, &sec.to_le_bytes())?; + if sec.header.get_type() == ShType::StrTab { + sec.header.sh_offset = offset as u64 + u64::from(SHS); + } + offset += writer.write(&sec.header.to_le_bytes())?; + if sec.header.get_type() == ShType::StrTab { + offset += writer.write(&sec.to_le_bytes())?; + } } - eprintln!("SHT: {}", offset); - // write section header table - for sec in self.file.sections.iter() { - offset += writer.write(&sec.header.to_le_bytes())?; + // program data (segments) + offset += pad_to_next_page(&mut writer, offset)?; + eprintln!("Prog start: {}", offset); + // write section/segment data + for bytes in self.input_data.program_bytes() { + offset += writer.write(bytes)?; + } + offset += pad_to_next_page(&mut writer, offset)?; + + eprintln!("Data start: {}", offset); + for bytes in self.input_data.data_bytes() { + offset += writer.write(bytes)?; } + writer.flush()?; Ok(self.destination) @@ -213,7 +223,7 @@ fn file_writer(output_filename: &str, permission: u32) -> Result let file = std::fs::OpenOptions::new() .create(true) - .read(true) + .truncate(true) .write(true) .mode(permission) .open(output_filename)?; @@ -271,14 +281,13 @@ fn next_page(size: u64) -> u64 { page_size * pages_needed } -fn write_padded(writer: &mut BufWriter, offset: usize, data: &[u8]) -> Result { +fn pad_to_next_page(writer: &mut BufWriter, offset: usize) -> Result { let page_size = page_size::get(); - let mut written = 0usize; - written += writer.write(data)?; - let padding = page_size - (page_size % offset); + let padding = page_size - (offset % page_size); - written += writer.get_mut().seek(SeekFrom::Current(padding as i64))? as usize; + eprintln!("Padding from: {} with: {}", offset, padding); + writer.seek(SeekFrom::Current(padding.try_into()?))?; - Ok(written) + Ok(padding) } diff --git a/src/formats/elf/segment.rs b/src/formats/elf/segment.rs index 4ad8d22..56a3ff6 100644 --- a/src/formats/elf/segment.rs +++ b/src/formats/elf/segment.rs @@ -1,5 +1,5 @@ use crate::common::SectionInfo; -use crate::common::{Section, SectionDataIterator}; +use crate::common::{Section}; use crate::error::Error; const SI_TEXT: usize = 0; @@ -15,9 +15,9 @@ pub enum SegmentType { const SEGMENT_NAMES: [&str; 4] = [".text", ".rodata", ".data", ".bss"]; -pub struct SegmentData<'data>([Vec>; 4]); +pub struct InputData<'data>([Vec>; 4]); -impl<'data> SegmentData<'data> { +impl<'data> InputData<'data> { pub fn new() -> Self { Self([Vec::new(), Vec::new(), Vec::new(), Vec::new()]) } @@ -42,20 +42,18 @@ impl<'data> SegmentData<'data> { .map(|(i, s)| (SEGMENT_NAMES[i], s)) } - pub fn program_data<'local>(&'local self) -> Box + 'local> { + pub fn program_bytes<'local>(&'local self) -> impl Iterator { let text_iter = self.0[SI_TEXT].iter(); let rodata_iter = self.0[SI_RODATA].iter(); - let data1 = text_iter.filter_map(|si| match si.data.as_ref() { - Some(iter) => Some(iter.clone_to_box()), - None => None, - }); - let data2 = rodata_iter.filter_map(|si| match si.data.as_ref() { - Some(iter) => Some(iter.clone_to_box()), - None => None, - }); + let data1 = text_iter.filter_map(|si| si.data); + let data2 = rodata_iter.filter_map(|si| si.data); - Box::new(data1.chain(data2).flatten()) + data1.chain(data2) + } + + pub fn data_bytes<'local>(&'local self) -> impl Iterator { + self.0[SI_DATA].iter().filter_map(|si| si.data) } // .text + .rodata @@ -92,7 +90,7 @@ impl<'data> SegmentData<'data> { } } -impl Default for SegmentData<'_> { +impl Default for InputData<'_> { fn default() -> Self { Self::new() } diff --git a/src/linker.rs b/src/linker.rs index a3bf6f6..3a9cd94 100644 --- a/src/linker.rs +++ b/src/linker.rs @@ -19,27 +19,13 @@ impl<'data> Linker<'data> { } pub fn link(&'data self, output: &mut dyn Output<'data>) -> Result { - let allocated = output.allocate(self.total_size()?)?; - for r in self.relocatables.iter() { for s in r.sections() { output.append_section(s?)?; } } - Ok(allocated) - } - - fn total_size(&self) -> Result { - let mut result = 0u64; - - for o in self.relocatables.iter() { - for s in o.sections() { - result += s?.size()?; - } - } - - Ok(result) + Ok(0) } }