--- /dev/null
+// RUN: %clang_dfsan %s -mllvm -dfsan-combine-offset-labels-on-gep=false -o %t && %run %t
+// RUN: %clang_dfsan %s -DPROP_OFFSET_LABELS -o %t && %run %t
+//
+// REQUIRES: x86_64-target-arch
+
+// Tests that labels are propagated through GEP.
+
+#include <sanitizer/dfsan_interface.h>
+#include <assert.h>
+
+int main(void) {
+ int i = 1;
+ int *p = &i;
+ int j = 2;
+ // test that pointer arithmetic propagates labels in terms of the flag.
+ dfsan_set_label(1, &i, sizeof(i));
+ p += i;
+#ifdef PROP_OFFSET_LABELS
+ assert(dfsan_get_label(p) == 1);
+#else
+ assert(dfsan_get_label(p) == 0);
+#endif
+ // test that non-pointer operations always propagate labels.
+ dfsan_set_label(2, &j, sizeof(j));
+ j += i;
+ assert(dfsan_get_label(j) == 3);
+ return 0;
+}
"storing in memory."),
cl::Hidden, cl::init(false));
+// Controls whether the pass propagates labels of offsets in GEP instructions.
+static cl::opt<bool> ClCombineOffsetLabelsOnGEP(
+ "dfsan-combine-offset-labels-on-gep",
+ cl::desc(
+ "Combine the label of the offset with the label of the pointer when "
+ "doing pointer arithmetic."),
+ cl::Hidden, cl::init(true));
+
static cl::opt<bool> ClDebugNonzeroLabels(
"dfsan-debug-nonzero-labels",
cl::desc("Insert calls to __dfsan_nonzero_label on observing a parameter, "
}
void DFSanVisitor::visitGetElementPtrInst(GetElementPtrInst &GEPI) {
- visitInstOperands(GEPI);
+ if (ClCombineOffsetLabelsOnGEP) {
+ visitInstOperands(GEPI);
+ return;
+ }
+
+ // Only propagate shadow/origin of base pointer value but ignore those of
+ // offset operands.
+ Value *BasePointer = GEPI.getPointerOperand();
+ DFSF.setShadow(&GEPI, DFSF.getShadow(BasePointer));
+ if (DFSF.DFS.shouldTrackOrigins())
+ DFSF.setOrigin(&GEPI, DFSF.getOrigin(BasePointer));
}
void DFSanVisitor::visitExtractElementInst(ExtractElementInst &I) {
--- /dev/null
+; RUN: opt < %s -dfsan -dfsan-track-origins=1 -dfsan-combine-offset-labels-on-gep=false -dfsan-fast-8-labels=true -S | FileCheck %s --check-prefixes=CHECK,CHECK_ORIGIN
+; RUN: opt < %s -dfsan -dfsan-combine-offset-labels-on-gep=false -dfsan-fast-8-labels=true -S | FileCheck %s
+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"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK: @__dfsan_arg_tls = external thread_local(initialexec) global [[TLS_ARR:\[100 x i64\]]]
+; CHECK: @__dfsan_retval_tls = external thread_local(initialexec) global [[TLS_ARR]]
+; CHECK: @__dfsan_shadow_width_bits = weak_odr constant i32 [[#SBITS:]]
+
+define i32* @gepop([10 x [20 x i32]]* %p, i32 %a, i32 %b, i32 %c) {
+ ; CHECK: @"dfs$gepop"
+ ; CHECK_ORIGIN: %[[#PO:]] = load i32, i32* getelementptr inbounds ([200 x i32], [200 x i32]* @__dfsan_arg_origin_tls, i64 0, i64 0), align [[ALIGN_O:4]]
+ ; CHECK: %[[#PS:]] = load i[[#SBITS]], i[[#SBITS]]* bitcast ([[TLS_ARR]]* @__dfsan_arg_tls to i[[#SBITS]]*), align [[ALIGN_S:2]]
+ ; CHECK: %e = getelementptr [10 x [20 x i32]], [10 x [20 x i32]]* %p, i32 %a, i32 %b, i32 %c
+ ; CHECK: store i[[#SBITS]] %[[#PS]], i[[#SBITS]]* bitcast ([[TLS_ARR]]* @__dfsan_retval_tls to i[[#SBITS]]*), align [[ALIGN_S]]
+ ; CHECK_ORIGIN: store i32 %[[#PO]], i32* @__dfsan_retval_origin_tls, align [[ALIGN_O]]
+
+ %e = getelementptr [10 x [20 x i32]], [10 x [20 x i32]]* %p, i32 %a, i32 %b, i32 %c
+ ret i32* %e
+}
+