fortrangoingonforty/afs-ld / 1eae32b

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Respect direct address materialization

Authored by espadonne
SHA
1eae32b5b9e0b24c3c0c371cc89cf7490363aeb9
Parents
9454823
Tree
14fc4c3

2 changed files

StatusFile+-
M src/icf.rs 14 7
M tests/linker_run.rs 98 0
src/icf.rsmodified
@@ -3,9 +3,7 @@ use std::fmt;
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 use crate::atom::{Atom, AtomFlags, AtomSection, AtomTable};
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 use crate::layout::LayoutInput;
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-use crate::reloc::{
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-    parse_raw_relocs, parse_relocs, Referent, Reloc, RelocKind, RelocLength,
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-};
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+use crate::reloc::{parse_raw_relocs, parse_relocs, Referent, Reloc, RelocKind, RelocLength};
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 use crate::resolve::{AtomId, InputId, Symbol, SymbolId, SymbolTable};
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 #[derive(Debug, Clone, Default)]
@@ -227,8 +225,10 @@ fn fold_order_key(
227225
     order_by_input: &HashMap<InputId, (usize, Option<u32>)>,
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     atom_id: AtomId,
229227
 ) -> (usize, u32, u32, u32) {
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-    let (load_order, archive_member_offset) =
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-        order_by_input.get(&atom.origin).copied().unwrap_or((usize::MAX, None));
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+    let (load_order, archive_member_offset) = order_by_input
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+        .get(&atom.origin)
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+        .copied()
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+        .unwrap_or((usize::MAX, None));
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     (
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         load_order,
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         archive_member_offset.unwrap_or(0),
@@ -363,6 +363,8 @@ fn marks_address_taken(kind: RelocKind) -> bool {
363363
     matches!(
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         kind,
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         RelocKind::Unsigned
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+            | RelocKind::Page21
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+            | RelocKind::PageOff12
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             | RelocKind::PointerToGot
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             | RelocKind::GotLoadPage21
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             | RelocKind::GotLoadPageOff12
@@ -375,7 +377,9 @@ fn relocs_for_atom<'a>(relocs: &'a [Reloc], atom: &Atom) -> impl Iterator<Item =
375377
     let start = atom.input_offset;
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     let end = atom.input_offset.saturating_add(atom.size);
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     relocs.iter().copied().filter(move |reloc| {
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-        let reloc_end = reloc.offset.saturating_add(reloc.length.byte_width() as u32);
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+        let reloc_end = reloc
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+            .offset
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+            .saturating_add(reloc.length.byte_width() as u32);
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         reloc.offset >= start && reloc_end <= end
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     })
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 }
@@ -469,7 +473,10 @@ fn atom_symbols(atom: &Atom) -> impl Iterator<Item = SymbolId> + '_ {
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 }
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 fn symbol_name(sym_table: &SymbolTable, symbol_id: SymbolId) -> String {
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-    sym_table.interner.resolve(sym_table.get(symbol_id).name()).to_string()
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+    sym_table
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+        .interner
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+        .resolve(sym_table.get(symbol_id).name())
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+        .to_string()
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 }
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475482
 fn target_atoms_for_reloc(
tests/linker_run.rsmodified
@@ -7051,6 +7051,104 @@ fn linker_run_icf_safe_keeps_address_taken_functions_distinct() {
70517051
     let _ = fs::remove_file(our_out);
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 }
70537053
7054
+#[test]
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+fn linker_run_icf_safe_keeps_adrp_add_address_taken_functions_distinct() {
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+    if !have_xcrun() {
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+        eprintln!("skipping: xcrun unavailable");
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+        return;
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+    };
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+
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+    let obj = scratch("icf-adrp-address-taken.o");
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+    let baseline_out = scratch("icf-adrp-address-taken-baseline.out");
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+    let our_out = scratch("icf-adrp-address-taken-ours.out");
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+    let src = r#"
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+        .section __TEXT,__text,regular,pure_instructions
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+        .globl _main
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+        _main:
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+            stp x29, x30, [sp, #-16]!
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+            mov x29, sp
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+            adrp x10, _helper1@PAGE
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+            add x10, x10, _helper1@PAGEOFF
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+            adrp x11, _helper2@PAGE
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+            add x11, x11, _helper2@PAGEOFF
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+            cmp x10, x11
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+            b.ne 1f
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+            mov w0, #1
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+            ldp x29, x30, [sp], #16
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+            ret
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+        1:
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+            mov w0, #0
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+            ldp x29, x30, [sp], #16
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+            ret
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+
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+        .private_extern _helper1
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+        _helper1:
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+            mov w0, #7
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+            ret
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+
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+        .private_extern _helper2
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+        _helper2:
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+            mov w0, #7
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+            ret
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+        .subsections_via_symbols
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+    "#;
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+    if let Err(e) = assemble(src, &obj) {
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+        eprintln!("skipping: assemble failed: {e}");
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+        return;
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+    }
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+
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+    let baseline_opts = LinkOptions {
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+        inputs: vec![obj.clone()],
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+        output: Some(baseline_out.clone()),
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+        kind: OutputKind::Executable,
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+        ..LinkOptions::default()
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+    };
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+    Linker::run(&baseline_opts).unwrap();
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+
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+    let opts = LinkOptions {
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+        inputs: vec![obj.clone()],
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+        output: Some(our_out.clone()),
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+        kind: OutputKind::Executable,
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+        icf_mode: afs_ld::IcfMode::Safe,
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+        ..LinkOptions::default()
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+    };
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+    Linker::run(&opts).unwrap();
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+
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+    let baseline_bytes = fs::read(&baseline_out).unwrap();
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+    let our_bytes = fs::read(&our_out).unwrap();
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+    let baseline_symbols = symbol_values(&baseline_bytes);
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+    let our_symbols = symbol_values(&our_bytes);
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+    let baseline_text = output_section(&baseline_bytes, "__TEXT", "__text")
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+        .unwrap()
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+        .1;
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+    let our_text = output_section(&our_bytes, "__TEXT", "__text").unwrap().1;
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+
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+    assert_ne!(
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+        our_symbols.get("_helper1"),
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+        our_symbols.get("_helper2"),
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+        "adrp/add address-taken helpers should not be folded by afs-ld -icf=safe"
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+    );
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+    assert_ne!(
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+        baseline_symbols.get("_helper1"),
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+        baseline_symbols.get("_helper2"),
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+        "baseline link should keep adrp/add address-taken helpers separate"
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+    );
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+    assert_eq!(
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+        Command::new(&our_out).status().unwrap().code(),
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+        Some(0),
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+        "adrp/add address-taken executable should preserve pointer inequality"
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+    );
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+    assert_eq!(
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+        our_text.len(),
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+        baseline_text.len(),
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+        "adrp/add address-taken helpers should not shrink under -icf=safe"
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+    );
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+
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+    let _ = fs::remove_file(obj);
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+    let _ = fs::remove_file(baseline_out);
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+    let _ = fs::remove_file(our_out);
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+}
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+
70547152
 #[test]
70557153
 fn linker_run_icf_safe_folds_matching_branch_relocs() {
70567154
     if !have_xcrun() {