Skip to content

[lld-macho] Fix ICF differentiation of safe_thunks relocs #111811

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Oct 10, 2024
Merged

[lld-macho] Fix ICF differentiation of safe_thunks relocs #111811

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 11 additions & 0 deletions lld/MachO/ICF.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -147,6 +147,17 @@ bool ICF::equalsConstant(const ConcatInputSection *ia,
isecB = rb.referent.get<InputSection *>();
}

// Typically, we should not encounter sections marked with `keepUnique` at
// this point as they would have resulted in different hashes and therefore
// no need for a full comparison.
// However, in `safe_thunks` mode, it's possible for two different
// relocations to reference identical `keepUnique` functions that will be
// distinguished later via thunks - so we need to handle this case
// explicitly.
if ((isecA != isecB) && ((isecA->keepUnique && isCodeSection(isecA)) ||
(isecB->keepUnique && isCodeSection(isecB))))
return false;

if (isecA->parent != isecB->parent)
return false;
// Sections with identical parents should be of the same kind.
Expand Down
49 changes: 49 additions & 0 deletions lld/test/MachO/icf-safe-thunks.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,13 @@
; CHECK-ARM64-NEXT: _func_3identical_v3_canmerge:
; CHECK-ARM64-NEXT: mov {{.*}}, #0x21
;
; CHECK-ARM64: _func_call_thunked_1_nomerge:
; CHECK-ARM64-NEXT: stp x29
;
; CHECK-ARM64: _func_call_thunked_2_nomerge:
; CHECK-ARM64-NEXT: _func_call_thunked_2_merge:
; CHECK-ARM64-NEXT: stp x29
;
; CHECK-ARM64: _call_all_funcs:
; CHECK-ARM64-NEXT: stp x29
;
Expand All @@ -43,6 +50,9 @@
; CHECK-ARM64-MAP-NEXT: 0x00000010 [ 2] _func_3identical_v1_canmerge
; CHECK-ARM64-MAP-NEXT: 0x00000000 [ 2] _func_3identical_v2_canmerge
; CHECK-ARM64-MAP-NEXT: 0x00000000 [ 2] _func_3identical_v3_canmerge
; CHECK-ARM64-MAP-NEXT: 0x00000020 [ 2] _func_call_thunked_1_nomerge
; CHECK-ARM64-MAP-NEXT: 0x00000020 [ 2] _func_call_thunked_2_nomerge
; CHECK-ARM64-MAP-NEXT: 0x00000000 [ 2] _func_call_thunked_2_merge
; CHECK-ARM64-MAP-NEXT: 0x00000034 [ 2] _call_all_funcs
; CHECK-ARM64-MAP-NEXT: 0x00000050 [ 2] _take_func_addr
; CHECK-ARM64-MAP-NEXT: 0x00000004 [ 2] _func_2identical_v2
Expand Down Expand Up @@ -125,6 +135,30 @@ entry:
ret void
}

; Function Attrs: mustprogress nofree noinline norecurse nounwind ssp memory(readwrite, argmem: none) uwtable(sync)
define void @func_call_thunked_1_nomerge() local_unnamed_addr #0 {
entry:
tail call void @func_2identical_v1()
store volatile i8 77, ptr @g_val, align 1, !tbaa !5
ret void
}

; Function Attrs: mustprogress nofree noinline norecurse nounwind ssp memory(readwrite, argmem: none) uwtable(sync)
define void @func_call_thunked_2_nomerge() local_unnamed_addr #0 {
entry:
tail call void @func_2identical_v2()
store volatile i8 77, ptr @g_val, align 1, !tbaa !5
ret void
}

; Function Attrs: mustprogress nofree noinline norecurse nounwind ssp memory(readwrite, argmem: none) uwtable(sync)
define void @func_call_thunked_2_merge() local_unnamed_addr #0 {
entry:
tail call void @func_2identical_v2()
store volatile i8 77, ptr @g_val, align 1, !tbaa !5
ret void
}

; Function Attrs: mustprogress nofree noinline norecurse nounwind ssp uwtable(sync)
define void @call_all_funcs() local_unnamed_addr #1 {
entry:
Expand Down Expand Up @@ -227,6 +261,21 @@ attributes #1 = { mustprogress nofree noinline norecurse nounwind ssp uwtable(sy
; g_val = 33;
; }
;
; ATTR void func_call_thunked_1_nomerge() {
; func_2identical_v1();
; g_val = 77;
; }
;
; ATTR void func_call_thunked_2_nomerge() {
; func_2identical_v2();
; g_val = 77;
; }
;
; ATTR void func_call_thunked_2_merge() {
; func_2identical_v2();
; g_val = 77;
; }
;
; ATTR void call_all_funcs() {
; func_unique_1();
; func_unique_2_canmerge();
Expand Down
Loading