[Clang] Disable use of the counted_by attribute for whole struct pointers #112636
+110
−194
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The whole struct is specificed in the __bdos. The calculation of the
whole size of the structure can be done in two ways:
1) sizeof(struct S) + count * sizeof(typeof(fam))
2) offsetof(struct S, fam) + count * sizeof(typeof(fam))
The first will add any remaining whitespace that might exist after
allocation while the second method is more precise, but not quite
expected from programmers. See [1] for a discussion of the topic.
GCC isn't (currently) able to calculate __bdos on a pointer to the whole
structure. Therefore, because of the above issue, we'll choose to match
what GCC does for consistency's sake.
[1] https://lore.kernel.org/lkml/ZvV6X5FPBBW7CO1f@archlinux/ for a
llvmbot
added
clang
|
@llvm/pr-subscribers-clang @llvm/pr-subscribers-clang-codegen Author: Bill Wendling (bwendling) ChangesThe whole struct is specificed in the __bdos. The calculation of the whole size of the structure can be done in two ways: The first will add any remaining whitespace that might exist after allocation while the second method is more precise, but not quite expected from programmers. See [1] for a discussion of the topic. GCC isn't (currently) able to calculate __bdos on a pointer to the whole structure. Therefore, because of the above issue, we'll choose to match what GCC does for consistency's sake. [1] https://lore.kernel.org/lkml/ZvV6X5FPBBW7CO1f@archlinux/ for a Patch is 54.41 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/112636.diff 2 Files Affected:
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index f6d7db2c204c12..362d9182e026f8 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1013,6 +1013,24 @@ CodeGenFunction::emitFlexibleArrayMemberSize(const Expr *E, unsigned Type,
// Can't find the field referenced by the "counted_by" attribute.
return nullptr;
+ if (isa<DeclRefExpr>(Base))
+ // The whole struct is specificed in the __bdos. The calculation of the
+ // whole size of the structure can be done in two ways:
+ //
+ // 1) sizeof(struct S) + count * sizeof(typeof(fam))
+ // 2) offsetof(struct S, fam) + count * sizeof(typeof(fam))
+ //
+ // The first will add any remaining whitespace that might exist after
+ // allocation while the second method is more precise, but not quite
+ // expected from programmers. See
+ // https://lore.kernel.org/lkml/ZvV6X5FPBBW7CO1f@archlinux/ for a
+ // discussion of the topic.
+ //
+ // GCC isn't (currently) able to calculate __bdos on a pointer to the whole
+ // structure. Therefore, because of the above issue, we'll choose to match
+ // what GCC does for consistency's sake.
+ return nullptr;
+
// Build a load of the counted_by field.
bool IsSigned = CountedByFD->getType()->isSignedIntegerType();
Value *CountedByInst = EmitLoadOfCountedByField(Base, FAMDecl, CountedByFD);
@@ -1043,32 +1061,9 @@ CodeGenFunction::emitFlexibleArrayMemberSize(const Expr *E, unsigned Type,
CharUnits Size = Ctx.getTypeSizeInChars(ArrayTy->getElementType());
llvm::Constant *ElemSize =
llvm::ConstantInt::get(ResType, Size.getQuantity(), IsSigned);
- Value *FAMSize =
+ Value *Res =
Builder.CreateMul(CountedByInst, ElemSize, "", !IsSigned, IsSigned);
- FAMSize = Builder.CreateIntCast(FAMSize, ResType, IsSigned);
- Value *Res = FAMSize;
-
- if (isa<DeclRefExpr>(Base)) {
- // The whole struct is specificed in the __bdos.
- const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(OuterRD);
-
- // Get the offset of the FAM.
- llvm::Constant *FAMOffset = ConstantInt::get(ResType, Offset, IsSigned);
- Value *OffsetAndFAMSize =
- Builder.CreateAdd(FAMOffset, Res, "", !IsSigned, IsSigned);
-
- // Get the full size of the struct.
- llvm::Constant *SizeofStruct =
- ConstantInt::get(ResType, Layout.getSize().getQuantity(), IsSigned);
-
- // max(sizeof(struct s),
- // offsetof(struct s, array) + p->count * sizeof(*p->array))
- Res = IsSigned
- ? Builder.CreateBinaryIntrinsic(llvm::Intrinsic::smax,
- OffsetAndFAMSize, SizeofStruct)
- : Builder.CreateBinaryIntrinsic(llvm::Intrinsic::umax,
- OffsetAndFAMSize, SizeofStruct);
- }
+ Res = Builder.CreateIntCast(Res, ResType, IsSigned);
// A negative \p IdxInst or \p CountedByInst means that the index lands
// outside of the flexible array member. If that's the case, we want to
diff --git a/clang/test/CodeGen/attr-counted-by.c b/clang/test/CodeGen/attr-counted-by.c
index 4a130c5e3d401f..f70e552bca26ab 100644
--- a/clang/test/CodeGen/attr-counted-by.c
+++ b/clang/test/CodeGen/attr-counted-by.c
@@ -66,7 +66,7 @@ struct anon_struct {
// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = icmp ult i64 [[IDXPROM]], [[TMP0]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP1]], label [[CONT3:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF3:![0-9]+]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: handler.out_of_bounds:
-// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB1:[0-9]+]], i64 [[IDXPROM]]) #[[ATTR10:[0-9]+]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB1:[0-9]+]], i64 [[IDXPROM]]) #[[ATTR9:[0-9]+]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: cont3:
// SANITIZE-WITH-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 12
@@ -114,7 +114,7 @@ void test1(struct annotated *p, int index, int val) {
// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = icmp ult i64 [[INDEX]], [[TMP0]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP1]], label [[CONT3:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF3]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: handler.out_of_bounds:
-// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB3:[0-9]+]], i64 [[INDEX]]) #[[ATTR10]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB3:[0-9]+]], i64 [[INDEX]]) #[[ATTR9]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: cont3:
// SANITIZE-WITH-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 12
@@ -197,42 +197,26 @@ size_t test2_bdos(struct annotated *p) {
// SANITIZE-WITH-ATTR-LABEL: define dso_local void @test3(
// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
// SANITIZE-WITH-ATTR-NEXT: entry:
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD:%.*]] = load i32, ptr [[DOT_COUNTED_BY_GEP]], align 4
-// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = zext i32 [[DOT_COUNTED_BY_LOAD]] to i64, !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: [[DOTCOUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
+// SANITIZE-WITH-ATTR-NEXT: [[DOTCOUNTED_BY_LOAD:%.*]] = load i32, ptr [[DOTCOUNTED_BY_GEP]], align 4
+// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = zext i32 [[DOTCOUNTED_BY_LOAD]] to i64, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = icmp ult i64 [[INDEX]], [[TMP0]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP1]], label [[CONT3:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF3]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: handler.out_of_bounds:
-// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB4:[0-9]+]], i64 [[INDEX]]) #[[ATTR10]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB4:[0-9]+]], i64 [[INDEX]]) #[[ATTR9]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: cont3:
// SANITIZE-WITH-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 12
// SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds nuw [0 x i32], ptr [[ARRAY]], i64 0, i64 [[INDEX]]
-// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = sext i32 [[DOT_COUNTED_BY_LOAD]] to i64
-// SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = shl nsw i64 [[TMP2]], 2
-// SANITIZE-WITH-ATTR-NEXT: [[TMP4:%.*]] = tail call i64 @llvm.smax.i64(i64 [[TMP3]], i64 4)
-// SANITIZE-WITH-ATTR-NEXT: [[TMP5:%.*]] = trunc i64 [[TMP4]] to i32
-// SANITIZE-WITH-ATTR-NEXT: [[TMP6:%.*]] = add i32 [[TMP5]], 12
-// SANITIZE-WITH-ATTR-NEXT: [[DOTINV:%.*]] = icmp slt i32 [[DOT_COUNTED_BY_LOAD]], 0
-// SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = select i1 [[DOTINV]], i32 0, i32 [[TMP6]]
-// SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA4]]
+// SANITIZE-WITH-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA4]]
// SANITIZE-WITH-ATTR-NEXT: ret void
//
// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local void @test3(
-// NO-SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i64 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
// NO-SANITIZE-WITH-ATTR-NEXT: entry:
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD:%.*]] = load i32, ptr [[DOT_COUNTED_BY_GEP]], align 4
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = sext i32 [[DOT_COUNTED_BY_LOAD]] to i64
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = shl nsw i64 [[TMP0]], 2
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = tail call i64 @llvm.smax.i64(i64 [[TMP1]], i64 4)
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = trunc i64 [[TMP2]] to i32
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP4:%.*]] = add i32 [[TMP3]], 12
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOTINV:%.*]] = icmp slt i32 [[DOT_COUNTED_BY_LOAD]], 0
-// NO-SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = select i1 [[DOTINV]], i32 0, i32 [[TMP4]]
// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAY:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 12
// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds nuw [0 x i32], ptr [[ARRAY]], i64 0, i64 [[INDEX]]
-// NO-SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITH-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
// NO-SANITIZE-WITH-ATTR-NEXT: ret void
//
// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test3(
@@ -254,34 +238,18 @@ size_t test2_bdos(struct annotated *p) {
void test3(struct annotated *p, size_t index) {
// This test differs from 'test2' by checking bdos on the whole array and not
// just the FAM.
- p->array[index] = __builtin_dynamic_object_size(p, 1);
+ p->array[index] = __builtin_dynamic_object_size(p, 0);
}
-// SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 0, 8589934601) i64 @test3_bdos(
-// SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef readonly [[P:%.*]]) local_unnamed_addr #[[ATTR2]] {
+// SANITIZE-WITH-ATTR-LABEL: define dso_local i64 @test3_bdos(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef readnone [[P:%.*]]) local_unnamed_addr #[[ATTR3:[0-9]+]] {
// SANITIZE-WITH-ATTR-NEXT: entry:
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD:%.*]] = load i32, ptr [[DOT_COUNTED_BY_GEP]], align 4
-// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = sext i32 [[DOT_COUNTED_BY_LOAD]] to i64
-// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = shl nsw i64 [[TMP0]], 2
-// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = tail call i64 @llvm.smax.i64(i64 [[TMP1]], i64 4)
-// SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = add nuw nsw i64 [[TMP2]], 12
-// SANITIZE-WITH-ATTR-NEXT: [[TMP4:%.*]] = icmp sgt i32 [[DOT_COUNTED_BY_LOAD]], -1
-// SANITIZE-WITH-ATTR-NEXT: [[TMP5:%.*]] = select i1 [[TMP4]], i64 [[TMP3]], i64 0
-// SANITIZE-WITH-ATTR-NEXT: ret i64 [[TMP5]]
+// SANITIZE-WITH-ATTR-NEXT: ret i64 -1
//
-// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 0, 8589934601) i64 @test3_bdos(
-// NO-SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef readonly [[P:%.*]]) local_unnamed_addr #[[ATTR2]] {
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local i64 @test3_bdos(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr noundef readnone [[P:%.*]]) local_unnamed_addr #[[ATTR3:[0-9]+]] {
// NO-SANITIZE-WITH-ATTR-NEXT: entry:
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD:%.*]] = load i32, ptr [[DOT_COUNTED_BY_GEP]], align 4
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = sext i32 [[DOT_COUNTED_BY_LOAD]] to i64
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = shl nsw i64 [[TMP0]], 2
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = tail call i64 @llvm.smax.i64(i64 [[TMP1]], i64 4)
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = add nuw nsw i64 [[TMP2]], 12
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP4:%.*]] = icmp sgt i32 [[DOT_COUNTED_BY_LOAD]], -1
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP5:%.*]] = select i1 [[TMP4]], i64 [[TMP3]], i64 0
-// NO-SANITIZE-WITH-ATTR-NEXT: ret i64 [[TMP5]]
+// NO-SANITIZE-WITH-ATTR-NEXT: ret i64 -1
//
// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local i64 @test3_bdos(
// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef readnone [[P:%.*]]) local_unnamed_addr #[[ATTR2:[0-9]+]] {
@@ -294,7 +262,7 @@ void test3(struct annotated *p, size_t index) {
// NO-SANITIZE-WITHOUT-ATTR-NEXT: ret i64 -1
//
size_t test3_bdos(struct annotated *p) {
- return __builtin_dynamic_object_size(p, 1);
+ return __builtin_dynamic_object_size(p, 0);
}
// SANITIZE-WITH-ATTR-LABEL: define dso_local void @test4(
@@ -308,7 +276,7 @@ size_t test3_bdos(struct annotated *p) {
// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = icmp ult i64 [[IDXPROM]], [[TMP0]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP1]], label [[CONT4:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF3]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: handler.out_of_bounds:
-// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB5:[0-9]+]], i64 [[IDXPROM]]) #[[ATTR10]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB5:[0-9]+]], i64 [[IDXPROM]]) #[[ATTR9]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: cont4:
// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = icmp sgt i32 [[DOT_COUNTED_BY_LOAD]], 2
@@ -325,7 +293,7 @@ size_t test3_bdos(struct annotated *p) {
// SANITIZE-WITH-ATTR-NEXT: [[TMP7:%.*]] = icmp ult i64 [[IDXPROM12]], [[TMP6]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP7]], label [[CONT19:%.*]], label [[HANDLER_OUT_OF_BOUNDS15:%.*]], !prof [[PROF3]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: handler.out_of_bounds15:
-// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB6:[0-9]+]], i64 [[IDXPROM12]]) #[[ATTR10]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB6:[0-9]+]], i64 [[IDXPROM12]]) #[[ATTR9]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: cont19:
// SANITIZE-WITH-ATTR-NEXT: [[TMP8:%.*]] = icmp sgt i32 [[DOT_COUNTED_BY_LOAD6]], 3
@@ -342,7 +310,7 @@ size_t test3_bdos(struct annotated *p) {
// SANITIZE-WITH-ATTR-NEXT: [[TMP13:%.*]] = icmp ult i64 [[IDXPROM28]], [[TMP12]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP13]], label [[CONT35:%.*]], label [[HANDLER_OUT_OF_BOUNDS31:%.*]], !prof [[PROF3]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: handler.out_of_bounds31:
-// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB7:[0-9]+]], i64 [[IDXPROM28]]) #[[ATTR10]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB7:[0-9]+]], i64 [[IDXPROM28]]) #[[ATTR9]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: cont35:
// SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX33:%.*]] = getelementptr inbounds [0 x i32], ptr [[ARRAY]], i64 0, i64 [[IDXPROM28]]
@@ -488,39 +456,27 @@ size_t test4_bdos(struct annotated *p, int index) {
// SANITIZE-WITH-ATTR-LABEL: define dso_local void @test5(
// SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i32 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
// SANITIZE-WITH-ATTR-NEXT: entry:
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD:%.*]] = load i64, ptr [[DOT_COUNTED_BY_GEP]], align 4
// SANITIZE-WITH-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
-// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = icmp ugt i64 [[DOT_COUNTED_BY_LOAD]], [[IDXPROM]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: [[DOTCOUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
+// SANITIZE-WITH-ATTR-NEXT: [[DOTCOUNTED_BY_LOAD:%.*]] = load i64, ptr [[DOTCOUNTED_BY_GEP]], align 4
+// SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = icmp ugt i64 [[DOTCOUNTED_BY_LOAD]], [[IDXPROM]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: br i1 [[TMP0]], label [[CONT3:%.*]], label [[HANDLER_OUT_OF_BOUNDS:%.*]], !prof [[PROF3]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: handler.out_of_bounds:
-// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB8:[0-9]+]], i64 [[IDXPROM]]) #[[ATTR10]], !nosanitize [[META2]]
+// SANITIZE-WITH-ATTR-NEXT: tail call void @__ubsan_handle_out_of_bounds_abort(ptr nonnull @[[GLOB8:[0-9]+]], i64 [[IDXPROM]]) #[[ATTR9]], !nosanitize [[META2]]
// SANITIZE-WITH-ATTR-NEXT: unreachable, !nosanitize [[META2]]
// SANITIZE-WITH-ATTR: cont3:
// SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 16
// SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [0 x i32], ptr [[TMP1]], i64 0, i64 [[IDXPROM]]
-// SANITIZE-WITH-ATTR-NEXT: [[DOTINV:%.*]] = icmp slt i64 [[DOT_COUNTED_BY_LOAD]], 0
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD_TR:%.*]] = trunc i64 [[DOT_COUNTED_BY_LOAD]] to i32
-// SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = shl i32 [[DOT_COUNTED_BY_LOAD_TR]], 2
-// SANITIZE-WITH-ATTR-NEXT: [[TMP3:%.*]] = add i32 [[TMP2]], 16
-// SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = select i1 [[DOTINV]], i32 0, i32 [[TMP3]]
-// SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA4]]
+// SANITIZE-WITH-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA4]]
// SANITIZE-WITH-ATTR-NEXT: ret void
//
// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local void @test5(
-// NO-SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef [[P:%.*]], i32 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITH-ATTR-SAME: ptr noundef [[P:%.*]], i32 noundef [[INDEX:%.*]]) local_unnamed_addr #[[ATTR0]] {
// NO-SANITIZE-WITH-ATTR-NEXT: entry:
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD:%.*]] = load i64, ptr [[DOT_COUNTED_BY_GEP]], align 4
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOTINV:%.*]] = icmp slt i64 [[DOT_COUNTED_BY_LOAD]], 0
-// NO-SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_LOAD_TR:%.*]] = trunc i64 [[DOT_COUNTED_BY_LOAD]] to i32
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = shl i32 [[DOT_COUNTED_BY_LOAD_TR]], 2
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP1:%.*]] = add i32 [[TMP0]], 16
-// NO-SANITIZE-WITH-ATTR-NEXT: [[CONV:%.*]] = select i1 [[DOTINV]], i32 0, i32 [[TMP1]]
-// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP2:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 16
+// NO-SANITIZE-WITH-ATTR-NEXT: [[TMP0:%.*]] = getelementptr inbounds nuw i8, ptr [[P]], i64 16
// NO-SANITIZE-WITH-ATTR-NEXT: [[IDXPROM:%.*]] = sext i32 [[INDEX]] to i64
-// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [0 x i32], ptr [[TMP2]], i64 0, i64 [[IDXPROM]]
-// NO-SANITIZE-WITH-ATTR-NEXT: store i32 [[CONV]], ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// NO-SANITIZE-WITH-ATTR-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [0 x i32], ptr [[TMP0]], i64 0, i64 [[IDXPROM]]
+// NO-SANITIZE-WITH-ATTR-NEXT: store i32 -1, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
// NO-SANITIZE-WITH-ATTR-NEXT: ret void
//
// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local void @test5(
@@ -545,27 +501,15 @@ void test5(struct anon_struct *p, int index) {
p->array[index] = __builtin_dynamic_object_size(p, 1);
}
-// SANITIZE-WITH-ATTR-LABEL: define dso_local range(i64 16, 1) i64 @test5_bdos(
-// SANITIZE-WITH-ATTR-SAME: ptr nocapture noundef readonly [[P:%.*]]) local_unnamed_addr #[[ATTR2]] {
+// SANITIZE-WITH-ATTR-LABEL: define dso_local i64 @test5_bdos(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef readnone [[P:%.*]]) local_unnamed_addr #[[ATTR3]] {
// SANITIZE-WITH-ATTR-NEXT: entry:
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COUNTED_BY_GEP:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 8
-// SANITIZE-WITH-ATTR-NEXT: [[DOT_COU...
[truncated]
|
efriedma-quic
approved these changes
Oct 17, 2024
| @@ -1013,6 +1013,24 @@ CodeGenFunction::emitFlexibleArrayMemberSize(const Expr *E, unsigned Type, | |||
| // Can't find the field referenced by the "counted_by" attribute. | |||
| return nullptr; | |||
|
|
|||
| if (isa<DeclRefExpr>(Base)) | |||
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I'm not sure this reliably detects a "whole struct"? It's not clear to me why we want to treat int f(struct X*p) { return __builtin_dynamic_object_size(p, 0); } differently from int f2(struct X**p) { return __builtin_dynamic_object_size(*p, 0); } here.
Maybe this is fine if other parts of the code detect "whole struct" the same way, though.
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It's possibly a bug, but we currently don't support int f2(struct X **p) { return __builtin_dynamic_object_size(*p, 0); } and just return -1. We do, however, support something like &p->array[0], which the hope is that it's more common than the previous. From what I can tell, this builtin is kind of a "best effort", so falling back to -1 when faced with something unexpected should hopefully only result in a bug report.
Co-authored-by: Eli Friedman <efriedma@quicinc.com>
bwendling
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to bwendling/llvm-project
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Oct 17, 2024
…ters (llvm#112636) The whole struct is specificed in the __bdos. The calculation of the whole size of the structure can be done in two ways: 1) sizeof(struct S) + count * sizeof(typeof(fam)) 2) offsetof(struct S, fam) + count * sizeof(typeof(fam)) The first will add any remaining whitespace that might exist after allocation while the second method is more precise, but not quite expected from programmers. See [1] for a discussion of the topic. GCC isn't (currently) able to calculate __bdos on a pointer to the whole structure. Therefore, because of the above issue, we'll choose to match what GCC does for consistency's sake. [1] https://lore.kernel.org/lkml/ZvV6X5FPBBW7CO1f@archlinux/ Co-authored-by: Eli Friedman <efriedma@quicinc.com>
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The whole struct is specificed in the __bdos. The calculation of the whole size of the structure can be done in two ways:
The first will add any remaining whitespace that might exist after allocation while the second method is more precise, but not quite expected from programmers. See [1] for a discussion of the topic.
GCC isn't (currently) able to calculate __bdos on a pointer to the whole structure. Therefore, because of the above issue, we'll choose to match what GCC does for consistency's sake.
[1] https://lore.kernel.org/lkml/ZvV6X5FPBBW7CO1f@archlinux/