Skip to content

[sancov] Fix stack-depth tracking to use debug locations #162428

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 2 commits into from
Oct 9, 2025
Merged

[sancov] Fix stack-depth tracking to use debug locations #162428

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
748de8d
[sancov] Fix stack-depth tracking to use debug locations
kees Oct 7, 2025
1abf5e6
Merge branch 'main' into fix-irbuilder
kees Oct 9, 2025
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
13 changes: 10 additions & 3 deletions llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1084,8 +1084,10 @@ void ModuleSanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
auto ThenTerm = SplitBlockAndInsertIfThen(
IRB.CreateIsNull(Load), &*IP, false,
MDBuilder(IRB.getContext()).createUnlikelyBranchWeights());
IRBuilder<> ThenIRB(ThenTerm);
InstrumentationIRBuilder ThenIRB(ThenTerm);
auto Store = ThenIRB.CreateStore(ConstantInt::getTrue(Int1Ty), FlagPtr);
if (EntryLoc)
Store->setDebugLoc(EntryLoc);
Load->setNoSanitizeMetadata();
Store->setNoSanitizeMetadata();
}
Expand Down Expand Up @@ -1131,7 +1133,10 @@ void ModuleSanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
EstimatedStackSize >= Options.StackDepthCallbackMin) {
if (InsertBefore)
IRB.SetInsertPoint(InsertBefore);
IRB.CreateCall(SanCovStackDepthCallback)->setCannotMerge();
auto Call = IRB.CreateCall(SanCovStackDepthCallback);
if (EntryLoc)
Call->setDebugLoc(EntryLoc);
Call->setCannotMerge();
}
} else {
// Check stack depth. If it's the deepest so far, record it.
Expand All @@ -1144,8 +1149,10 @@ void ModuleSanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
auto ThenTerm = SplitBlockAndInsertIfThen(
IsStackLower, &*IP, false,
MDBuilder(IRB.getContext()).createUnlikelyBranchWeights());
IRBuilder<> ThenIRB(ThenTerm);
InstrumentationIRBuilder ThenIRB(ThenTerm);
auto Store = ThenIRB.CreateStore(FrameAddrInt, SanCovLowestStack);
if (EntryLoc)
Store->setDebugLoc(EntryLoc);
LowestStack->setNoSanitizeMetadata();
Store->setNoSanitizeMetadata();
}
Expand Down
92 changes: 92 additions & 0 deletions llvm/test/Instrumentation/SanitizerCoverage/missing_dbg.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt < %s -passes='module(sancov-module)' -sanitizer-coverage-level=2 -S | FileCheck %s
; RUN: opt < %s -passes='module(sancov-module)' -sanitizer-coverage-level=1 -sanitizer-coverage-stack-depth -sanitizer-coverage-stack-depth-callback-min=1 -S | FileCheck %s --check-prefix=CHECK-STACK-CALLBACK
; RUN: opt < %s -passes='module(sancov-module)' -sanitizer-coverage-level=1 -sanitizer-coverage-stack-depth -S | FileCheck %s --check-prefix=CHECK-STACK-DEPTH

target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"

Expand Down Expand Up @@ -55,6 +57,86 @@ entry:
ret i32 %t
}

define i32 @with_dbg_stack_callback(ptr %a) !dbg !8 {
; CHECK-STACK-CALLBACK-LABEL: define i32 @with_dbg_stack_callback(
; CHECK-STACK-CALLBACK-SAME: ptr [[A:%.*]]) !dbg [[DBG8:![0-9]+]] {
; CHECK-STACK-CALLBACK-NEXT: entry:
; CHECK-STACK-CALLBACK-NEXT: [[BUF:%.*]] = alloca [64 x i8], align 1
; CHECK-STACK-CALLBACK-NEXT: call void @__sanitizer_cov_stack_depth() #[[ATTR1:[0-9]+]], !dbg [[DBG9:![0-9]+]]
; CHECK-STACK-CALLBACK-NEXT: %t = load i32, ptr [[A]], align 4
; CHECK-STACK-CALLBACK-NEXT: call void @external_func()
; CHECK-STACK-CALLBACK-NEXT: ret i32 %t
;
entry:
%buf = alloca [64 x i8], align 1
%t = load i32, ptr %a, align 4
call void @external_func()
ret i32 %t
}

define i32 @with_dbg_stack_depth(ptr %a) !dbg !10 {
; CHECK-STACK-DEPTH-LABEL: define i32 @with_dbg_stack_depth(
; CHECK-STACK-DEPTH-SAME: ptr [[A:%.*]]) !dbg [[DBG10:![0-9]+]] {
; CHECK-STACK-DEPTH-NEXT: entry:
; CHECK-STACK-DEPTH-NEXT: [[BUF:%.*]] = alloca [64 x i8], align 1
; CHECK-STACK-DEPTH-NEXT: [[TMP1:%.*]] = call ptr @llvm.frameaddress.p0(i32 0)
; CHECK-STACK-DEPTH-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; CHECK-STACK-DEPTH-NEXT: [[TMP3:%.*]] = load i64, ptr @__sancov_lowest_stack, align 8
; CHECK-STACK-DEPTH-NEXT: [[TMP4:%.*]] = icmp ult i64 [[TMP2]], [[TMP3]]
; CHECK-STACK-DEPTH-NEXT: br i1 [[TMP4]], label {{%.*}}, label {{%.*}}
; CHECK-STACK-DEPTH: store i64 [[TMP2]], ptr @__sancov_lowest_stack, align 8, !dbg [[DBG11:![0-9]+]], {{.*}}!nosanitize
; CHECK-STACK-DEPTH: %t = load i32, ptr [[A]], align 4
; CHECK-STACK-DEPTH-NEXT: call void @external_func()
; CHECK-STACK-DEPTH-NEXT: ret i32 %t
;
entry:
%buf = alloca [64 x i8], align 1
%t = load i32, ptr %a, align 4
call void @external_func()
ret i32 %t
}

define i32 @without_dbg_stack_callback(ptr %a) {
; CHECK-STACK-CALLBACK-LABEL: define i32 @without_dbg_stack_callback(
; CHECK-STACK-CALLBACK-SAME: ptr [[A:%.*]]) {
; CHECK-STACK-CALLBACK-NEXT: entry:
; CHECK-STACK-CALLBACK-NEXT: [[BUF:%.*]] = alloca [64 x i8], align 1
; CHECK-STACK-CALLBACK-NEXT: call void @__sanitizer_cov_stack_depth() #[[ATTR1]]
; CHECK-STACK-CALLBACK-NEXT: %t = load i32, ptr [[A]], align 4
; CHECK-STACK-CALLBACK-NEXT: call void @external_func()
; CHECK-STACK-CALLBACK-NEXT: ret i32 %t
;
entry:
%buf = alloca [64 x i8], align 1
%t = load i32, ptr %a, align 4
call void @external_func()
ret i32 %t
}

define i32 @without_dbg_stack_depth(ptr %a) {
; CHECK-STACK-DEPTH-LABEL: define i32 @without_dbg_stack_depth(
; CHECK-STACK-DEPTH-SAME: ptr [[A:%.*]]) {
; CHECK-STACK-DEPTH-NEXT: entry:
; CHECK-STACK-DEPTH-NEXT: [[BUF:%.*]] = alloca [64 x i8], align 1
; CHECK-STACK-DEPTH-NEXT: [[TMP1:%.*]] = call ptr @llvm.frameaddress.p0(i32 0)
; CHECK-STACK-DEPTH-NEXT: [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
; CHECK-STACK-DEPTH-NEXT: [[TMP3:%.*]] = load i64, ptr @__sancov_lowest_stack, align 8
; CHECK-STACK-DEPTH-NEXT: [[TMP4:%.*]] = icmp ult i64 [[TMP2]], [[TMP3]]
; CHECK-STACK-DEPTH-NEXT: br i1 [[TMP4]], label {{%.*}}, label {{%.*}}
; CHECK-STACK-DEPTH: store i64 [[TMP2]], ptr @__sancov_lowest_stack, align 8, {{.*}}!nosanitize
; CHECK-STACK-DEPTH: %t = load i32, ptr [[A]], align 4
; CHECK-STACK-DEPTH-NEXT: call void @external_func()
; CHECK-STACK-DEPTH-NEXT: ret i32 %t
;
entry:
%buf = alloca [64 x i8], align 1
%t = load i32, ptr %a, align 4
call void @external_func()
ret i32 %t
}

declare void @external_func()

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!2}

Expand All @@ -66,6 +148,10 @@ entry:
!5 = !{}
!6 = !DILocation(line: 192, scope: !3)
!7 = !DILocation(line: 0, scope: !3)
!8 = distinct !DISubprogram(name: "with_dbg_stack_callback", scope: !1, file: !1, line: 200, type: !4, scopeLine: 200, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!9 = !DILocation(line: 200, scope: !8)
!10 = distinct !DISubprogram(name: "with_dbg_stack_depth", scope: !1, file: !1, line: 210, type: !4, scopeLine: 210, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0)
!11 = !DILocation(line: 210, scope: !10)

;.
; CHECK: [[META0:![0-9]+]] = distinct !DICompileUnit(language: DW_LANG_C89, file: [[META1:![0-9]+]], isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, splitDebugInlining: false, nameTableKind: None)
Expand All @@ -76,3 +162,9 @@ entry:
; CHECK: [[DBG6]] = !DILocation(line: 192, scope: [[DBG3]])
; CHECK: [[DBG7]] = !DILocation(line: 0, scope: [[DBG3]])
;.
; CHECK-STACK-CALLBACK: [[DBG8]] = distinct !DISubprogram(name: "with_dbg_stack_callback", scope: {{.*}}, file: {{.*}}, line: 200
; CHECK-STACK-CALLBACK: [[DBG9]] = !DILocation(line: 200, scope: [[DBG8]])
;.
; CHECK-STACK-DEPTH: [[DBG10]] = distinct !DISubprogram(name: "with_dbg_stack_depth", scope: {{.*}}, file: {{.*}}, line: 210
; CHECK-STACK-DEPTH: [[DBG11]] = !DILocation(line: 210, scope: [[DBG10]])
;.