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Merge branch 'p12' into 'master'

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fix(ld_so/dso): `TPOFF` with undefined symbol index

See merge request redox-os/relibc!874
This commit is contained in:
Jeremy Soller
2026-01-07 22:10:05 -07:00
parent 8c20bc7899 79c0df3dda
commit 2c11d0f3cb
1 changed files with 23 additions and 8 deletions
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src/ld_so/dso.rs
+23 -8
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@@ -62,6 +62,9 @@ mod shim {
pub use shim::*;
/// Undefined Symbol Index
pub const STN_UNDEF: SymbolIndex = SymbolIndex(0);
enum HashTable<'a> {
Gnu(GnuHashTable<'a, FileHeader>),
Sysv(SysVHashTable<'a, FileHeader>),
@@ -878,7 +881,7 @@ impl DSO {
fn static_relocate(&self, global_scope: &Scope, reloc: Relocation) -> object::Result<()> {
let b = self.mmap.as_ptr() as usize;
let (sym, my_sym) = if reloc.sym.0 > 0 {
let (sym, my_sym) = if reloc.sym != STN_UNDEF {
let name = self.dynamic.symbol_name(reloc.sym).unwrap();
let lookup_scopes = [global_scope, self.scope()];
@@ -896,11 +899,18 @@ impl DSO {
(None, None)
};
let (s, t, tls_id) = sym
let (s, tls_obj) = sym
.as_ref()
.map(|(sym, obj)| (sym.as_ptr() as usize, obj.tls_offset, obj.tls_module_id))
// TODO: is self.tls_module_id the right fallback?
.unwrap_or((0, 0, self.tls_module_id));
.map(|(sym, obj)| (sym.as_ptr() as usize, obj.as_ref()))
// (1) According to the System V gABI (Chapter 4, "Relocation"): if
// the symbol index (`reloc.sym`) is undefined, the symbol value
// (`s`) is defined as 0.
//
// (2) According to Drepper's ELF Handling For Thread-Local Storage
// (Section 4.2, "Local Dynamic TLS Model"): a relocation with
// undefined symbol index implies a reference to the current module
// itself. Hence we resolve the object to `self`.
.unwrap_or((0, self));
let ptr = if self.pie {
(b + reloc.offset) as *mut u8
@@ -922,7 +932,7 @@ impl DSO {
};
match reloc.kind {
RelocationKind::DTPMOD => set_usize(tls_id),
RelocationKind::DTPMOD => set_usize(tls_obj.tls_module_id),
// TODO: Subtract DTP_OFFSET, which is 0x800 on riscv64, 0 on x86?
RelocationKind::DTPOFF => {
if reloc.sym.0 > 0 {
@@ -939,13 +949,18 @@ impl DSO {
RelocationKind::RELATIVE => set_usize(b + a),
RelocationKind::SYMBOLIC => set_usize(s + a),
RelocationKind::TPOFF => {
assert!(
!tls_obj.dlopened,
"The {{local/initial}}-exec access model is used for symbol '{}' in '{}', which requires a static TLS block. However, the definition in '{}' resides in the dynamic TLS block because the object was loaded via dlopen(2).",
reloc.sym, self.name, tls_obj.name
);
if reloc.sym.0 > 0 {
let (sym, _) = sym
.as_ref()
.expect("RelocationKind::TPOFF called without valid symbol");
set_usize((sym.value + a).wrapping_sub(t));
set_usize((sym.value + a).wrapping_sub(tls_obj.tls_offset));
} else {
set_usize(a.wrapping_sub(t));
set_usize(a.wrapping_sub(tls_obj.tls_offset));
}
}
RelocationKind::IRELATIVE => unsafe {