Skip to content

[msan] Enable msan-handle-asm-conservative for userspace by default #79251

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
Jan 24, 2024
Merged

[msan] Enable msan-handle-asm-conservative for userspace by default #79251

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
9 changes: 1 addition & 8 deletions llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -284,9 +284,6 @@ static cl::opt<bool> ClHandleLifetimeIntrinsics(
// passed into an assembly call. Note that this may cause false positives.
// Because it's impossible to figure out the array sizes, we can only unpoison
// the first sizeof(type) bytes for each type* pointer.
// The instrumentation is only enabled in KMSAN builds, and only if
// -msan-handle-asm-conservative is on. This is done because we may want to
// quickly disable assembly instrumentation when it breaks.
static cl::opt<bool> ClHandleAsmConservative(
"msan-handle-asm-conservative",
cl::desc("conservative handling of inline assembly"), cl::Hidden,
Expand Down Expand Up @@ -4103,11 +4100,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
// do the usual thing: check argument shadow and mark all outputs as
// clean. Note that any side effects of the inline asm that are not
// immediately visible in its constraints are not handled.
// For now, handle inline asm by default for KMSAN.
bool HandleAsm = ClHandleAsmConservative.getNumOccurrences()
? ClHandleAsmConservative
: MS.CompileKernel;
if (HandleAsm)
if (ClHandleAsmConservative)
visitAsmInstruction(CB);
else
visitInstruction(CB);
Expand Down
2 changes: 1 addition & 1 deletion llvm/test/Instrumentation/MemorySanitizer/msan_asm_conservative.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
; Test for handling of asm constraints in MSan instrumentation.
; RUN: opt < %s -msan-check-access-address=0 -msan-handle-asm-conservative=0 -S -passes=msan 2>&1 | \
; RUN: FileCheck %s
; RUN: opt < %s -msan-check-access-address=0 -msan-handle-asm-conservative=1 -S -passes=msan 2>&1 | \
; RUN: opt < %s -msan-check-access-address=0 -S -passes=msan 2>&1 | \
; RUN: FileCheck --check-prefixes=CHECK,USER-CONS %s
; RUN: opt < %s -msan-kernel=1 -msan-check-access-address=0 \
; RUN: -msan-handle-asm-conservative=0 -S -passes=msan 2>&1 | FileCheck \
Expand Down