a464465e2f
* Add `anyhow` dependency to `wasmtime-runtime`. * Revert `get_data` back to `fn`. * Remove `DataInitializer` and box the data in `Module` translation instead. * Improve comments on `MemoryInitialization`. * Remove `MemoryInitialization::OutOfBounds` in favor of proper bulk memory semantics. * Use segmented memory initialization except for when the uffd feature is enabled on Linux. * Validate modules with the allocator after translation. * Updated various functions in the runtime to return `anyhow::Result`. * Use a slice when copying pages instead of `ptr::copy_nonoverlapping`. * Remove unnecessary casts in `OnDemandAllocator::deallocate`. * Better document the `uffd` feature. * Use WebAssembly page-sized pages in the paged initialization. * Remove the stack pool from the uffd handler and simply protect just the guard pages.
93 lines
3.1 KiB
Rust
93 lines
3.1 KiB
Rust
use crate::builder::{ObjectBuilder, ObjectBuilderTarget};
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use crate::context::layout_vmcontext;
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use crate::data_segment::{declare_data_segment, emit_data_segment};
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use crate::table::{declare_table, emit_table};
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use anyhow::Result;
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use object::write::{Object, Relocation, StandardSection, Symbol, SymbolSection};
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use object::{RelocationEncoding, RelocationKind, SymbolFlags, SymbolKind, SymbolScope};
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use wasmtime_debug::DwarfSection;
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use wasmtime_environ::isa::TargetFrontendConfig;
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use wasmtime_environ::{CompiledFunctions, MemoryInitialization, Module};
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fn emit_vmcontext_init(
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obj: &mut Object,
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module: &Module,
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target_config: &TargetFrontendConfig,
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) -> Result<()> {
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let (data, table_relocs) = layout_vmcontext(module, target_config);
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let symbol_id = obj.add_symbol(Symbol {
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name: "_vmcontext_init".as_bytes().to_vec(),
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value: 0,
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size: 0,
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kind: SymbolKind::Data,
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scope: SymbolScope::Linkage,
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weak: false,
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section: SymbolSection::Undefined,
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flags: SymbolFlags::None,
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});
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let section_id = obj.section_id(StandardSection::Data);
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let section_offset = obj.add_symbol_data(symbol_id, section_id, &data, 1);
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for reloc in table_relocs.iter() {
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let target_name = format!("_table_{}", reloc.index);
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let target_symbol = obj.symbol_id(target_name.as_bytes()).unwrap();
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obj.add_relocation(
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section_id,
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Relocation {
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offset: section_offset + reloc.offset as u64,
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size: 64, // FIXME for all targets
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kind: RelocationKind::Absolute,
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encoding: RelocationEncoding::Generic,
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symbol: target_symbol,
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addend: 0,
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},
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)?;
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}
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Ok(())
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}
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/// Emits a module that has been emitted with the `wasmtime-environ` environment
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/// implementation to a native object file.
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pub fn emit_module(
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target: ObjectBuilderTarget,
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module: &Module,
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target_config: &TargetFrontendConfig,
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compilation: CompiledFunctions,
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dwarf_sections: Vec<DwarfSection>,
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) -> Result<Object> {
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let mut builder = ObjectBuilder::new(target, module, &compilation);
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builder.set_dwarf_sections(dwarf_sections);
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let mut obj = builder.build()?;
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// Append data, table and vmcontext_init code to the object file.
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match &module.memory_initialization {
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MemoryInitialization::Segmented(initializers) => {
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for (i, initializer) in initializers.iter().enumerate() {
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declare_data_segment(&mut obj, initializer, i)?;
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}
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}
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_ => unimplemented!(),
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}
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for i in 0..module.table_plans.len() {
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declare_table(&mut obj, i)?;
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}
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match &module.memory_initialization {
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MemoryInitialization::Segmented(initializers) => {
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for (i, initializer) in initializers.iter().enumerate() {
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emit_data_segment(&mut obj, initializer, i)?;
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}
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}
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_ => unimplemented!(),
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}
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for i in 0..module.table_plans.len() {
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emit_table(&mut obj, i)?;
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}
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emit_vmcontext_init(&mut obj, module, target_config)?;
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Ok(obj)
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}
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