[AllocToken] Enable alloc token instrumentation for size-returning functions #168840
+9
−9
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…nctions Consider a newly added "malloc_span" attribute in the allocation token instrumentation to ensure that __size_returning_new variants are correctly identified as memory allocation functions. Adjust the allocation token tests to verify this new behavior.
llvmbot
added
clang
Member
|
@llvm/pr-subscribers-clang @llvm/pr-subscribers-clang-codegen Author: Aleksandr Nogikh (a-nogikh) ChangesConsider a newly added "malloc_span" attribute in the allocation token instrumentation to ensure that __size_returning_new variants are correctly identified as memory allocation functions. Adjust the allocation token tests to verify this new behavior. Full diff: https://github.com/llvm/llvm-project/pull/168840.diff 2 Files Affected:
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index f2451b16e78be..712bec62f0a68 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -6644,6 +6644,7 @@ RValue CodeGenFunction::EmitCall(QualType CalleeType,
if (auto *CalleeDecl = dyn_cast_or_null<FunctionDecl>(TargetDecl)) {
if (CalleeDecl->hasAttr<RestrictAttr>() ||
+ CalleeDecl->hasAttr<MallocSpanAttr>() ||
CalleeDecl->hasAttr<AllocSizeAttr>()) {
// Function has 'malloc' (aka. 'restrict') or 'alloc_size' attribute.
if (SanOpts.has(SanitizerKind::AllocToken)) {
diff --git a/clang/test/CodeGenCXX/alloc-token.cpp b/clang/test/CodeGenCXX/alloc-token.cpp
index feed808a3b89b..98842206dfc00 100644
--- a/clang/test/CodeGenCXX/alloc-token.cpp
+++ b/clang/test/CodeGenCXX/alloc-token.cpp
@@ -17,10 +17,10 @@ struct __sized_ptr_t {
size_t n;
};
enum class __hot_cold_t : uint8_t;
-__sized_ptr_t __size_returning_new(size_t size);
-__sized_ptr_t __size_returning_new_hot_cold(size_t, __hot_cold_t);
-__sized_ptr_t __size_returning_new_aligned(size_t, std::align_val_t);
-__sized_ptr_t __size_returning_new_aligned_hot_cold(size_t, std::align_val_t, __hot_cold_t);
+__sized_ptr_t __size_returning_new(size_t size) __attribute__((malloc_span));
+__sized_ptr_t __size_returning_new_hot_cold(size_t, __hot_cold_t) __attribute__((malloc_span));
+__sized_ptr_t __size_returning_new_aligned(size_t, std::align_val_t) __attribute__((malloc_span));
+__sized_ptr_t __size_returning_new_aligned_hot_cold(size_t, std::align_val_t, __hot_cold_t) __attribute__((malloc_span));
}
void *sink; // prevent optimizations from removing the calls
@@ -101,12 +101,11 @@ int *test_new_array_nothrow() {
}
// CHECK-LABEL: define dso_local void @_Z23test_size_returning_newv(
-// CHECK: call { ptr, i64 } @__size_returning_new(i64 noundef 8)
-// CHECK: call { ptr, i64 } @__size_returning_new_hot_cold(i64 noundef 8, i8 noundef zeroext 1)
-// CHECK: call { ptr, i64 } @__size_returning_new_aligned(i64 noundef 8, i64 noundef 32)
-// CHECK: call { ptr, i64 } @__size_returning_new_aligned_hot_cold(i64 noundef 8, i64 noundef 32, i8 noundef zeroext 1)
+// CHECK: call { ptr, i64 } @__size_returning_new(i64 noundef 8){{.*}} !alloc_token [[META_LONG]]
+// CHECK: call { ptr, i64 } @__size_returning_new_hot_cold(i64 noundef 8, i8 noundef zeroext 1){{.*}} !alloc_token [[META_LONG]]
+// CHECK: call { ptr, i64 } @__size_returning_new_aligned(i64 noundef 8, i64 noundef 32){{.*}} !alloc_token [[META_LONG]]
+// CHECK: call { ptr, i64 } @__size_returning_new_aligned_hot_cold(i64 noundef 8, i64 noundef 32, i8 noundef zeroext 1){{.*}}_token [[META_LONG]]
void test_size_returning_new() {
- // FIXME: Support __size_returning_new variants.
sink = __size_returning_new(sizeof(long)).p;
sink = __size_returning_new_hot_cold(sizeof(long), __hot_cold_t{1}).p;
sink = __size_returning_new_aligned(sizeof(long), std::align_val_t{32}).p;
|
melver
approved these changes
Nov 20, 2025
Contributor
melver
left a comment
melver
left a comment
There was a problem hiding this comment.
LGTM
Re commit desc: Not only __size_returning_new (all decls will need the attribute to work, it won't work automatically), but all functions where we add the attribute.
With -fsanitize-alloc-token-extended it'll also work for custom non-standard allocations functions that add the attribute.
🐧 Linux x64 Test Results
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Consider a newly added "malloc_span" attribute in the allocation token instrumentation to ensure that allocation functions with the "malloc_span" attribute are processed similarly to other memory allocation functions.
Update the tests to demonstrate applicability to __size_returning_new.