[dfsan] Expose dfsan_get_track_origins to get origin tracking status

This allows application code checks if origin tracking is on before
printing out traces.

-dfsan-track-origins can be 0,1,2.
The current code only distinguishes 1 and 2 in compile time, but not at runtime.
Made runtime distinguish 1 and 2 too.

Reviewed By: browneee

Differential Revision: https://reviews.llvm.org/D105128

diff --git a/compiler-rt/include/sanitizer/dfsan_interface.h b/compiler-rt/include/sanitizer/dfsan_interface.h
index ea22832..cd3b6d6 100644 (file)
--- a/compiler-rt/include/sanitizer/dfsan_interface.h
+++ b/compiler-rt/include/sanitizer/dfsan_interface.h
@@ -141,6 +141,12 @@ size_t dfsan_sprint_stack_trace(char *out_buf, size_t out_buf_size);
 /// Retrieves the very first origin associated with the data at the given
 /// address.
 dfsan_origin dfsan_get_init_origin(const void *addr);
+
+/// Returns the value of -dfsan-track-origins.
+/// * 0: do not track origins.
+/// * 1: track origins at memory store operations.
+/// * 2: track origins at memory load and store operations.
+int dfsan_get_track_origins(void);
 #ifdef __cplusplus
 }  // extern "C"
 

diff --git a/compiler-rt/lib/dfsan/dfsan.cpp b/compiler-rt/lib/dfsan/dfsan.cpp
index a029500..6f9ae14 100644 (file)
--- a/compiler-rt/lib/dfsan/dfsan.cpp
+++ b/compiler-rt/lib/dfsan/dfsan.cpp
@@ -55,10 +55,11 @@ SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL u32
 // Instrumented code may set this value in terms of -dfsan-track-origins.
 // * undefined or 0: do not track origins.
 // * 1: track origins at memory store operations.
-// * 2: TODO: track origins at memory store operations and callsites.
+// * 2: track origins at memory load and store operations.
+//      TODO: track callsites.
 extern "C" SANITIZER_WEAK_ATTRIBUTE const int __dfsan_track_origins;
 
-int __dfsan_get_track_origins() {
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE int dfsan_get_track_origins() {
   return &__dfsan_track_origins ? __dfsan_track_origins : 0;
 }
 
@@ -446,7 +447,7 @@ void dfsan_copy_memory(void *dst, const void *src, uptr size) {
   internal_memcpy(dst, src, size);
   internal_memcpy((void *)shadow_for(dst), (const void *)shadow_for(src),
                   size * sizeof(dfsan_label));
-  if (__dfsan_get_track_origins())
+  if (dfsan_get_track_origins())
     dfsan_mem_origin_transfer(dst, src, size);
 }
 
@@ -514,12 +515,12 @@ void SetShadow(dfsan_label label, void *addr, uptr size, dfsan_origin origin) {
   if (0 != label) {
     const uptr beg_shadow_addr = (uptr)__dfsan::shadow_for(addr);
     WriteShadowWithSize(label, beg_shadow_addr, size);
-    if (__dfsan_get_track_origins())
+    if (dfsan_get_track_origins())
       SetOrigin(addr, size, origin);
     return;
   }
 
-  if (__dfsan_get_track_origins())
+  if (dfsan_get_track_origins())
     ReleaseOrigins(addr, size);
 
   ReleaseOrClearShadows(addr, size);
@@ -533,7 +534,7 @@ extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __dfsan_set_label(
 SANITIZER_INTERFACE_ATTRIBUTE
 void dfsan_set_label(dfsan_label label, void *addr, uptr size) {
   dfsan_origin init_origin = 0;
-  if (label && __dfsan_get_track_origins()) {
+  if (label && dfsan_get_track_origins()) {
     GET_CALLER_PC_BP;
     GET_STORE_STACK_TRACE_PC_BP(pc, bp);
     init_origin = ChainOrigin(0, &stack, true);
@@ -546,7 +547,7 @@ void dfsan_add_label(dfsan_label label, void *addr, uptr size) {
   if (0 == label)
     return;
 
-  if (__dfsan_get_track_origins()) {
+  if (dfsan_get_track_origins()) {
     GET_CALLER_PC_BP;
     GET_STORE_STACK_TRACE_PC_BP(pc, bp);
     dfsan_origin init_origin = ChainOrigin(0, &stack, true);
@@ -648,7 +649,7 @@ void PrintInvalidOriginWarning(dfsan_label label, const void *address) {
 bool PrintOriginTraceToStr(const void *addr, const char *description,
                            InternalScopedString *out) {
   CHECK(out);
-  CHECK(__dfsan_get_track_origins());
+  CHECK(dfsan_get_track_origins());
   Decorator d;
 
   const dfsan_label label = *__dfsan::shadow_for(addr);
@@ -687,7 +688,7 @@ bool PrintOriginTraceToStr(const void *addr, const char *description,
 
 extern "C" SANITIZER_INTERFACE_ATTRIBUTE void dfsan_print_origin_trace(
     const void *addr, const char *description) {
-  if (!__dfsan_get_track_origins()) {
+  if (!dfsan_get_track_origins()) {
     PrintNoOriginTrackingWarning();
     return;
   }
@@ -713,7 +714,7 @@ dfsan_sprint_origin_trace(const void *addr, const char *description,
                           char *out_buf, size_t out_buf_size) {
   CHECK(out_buf);
 
-  if (!__dfsan_get_track_origins()) {
+  if (!dfsan_get_track_origins()) {
     PrintNoOriginTrackingWarning();
     return 0;
   }
@@ -742,7 +743,7 @@ dfsan_sprint_origin_trace(const void *addr, const char *description,
 
 extern "C" SANITIZER_INTERFACE_ATTRIBUTE dfsan_origin
 dfsan_get_init_origin(const void *addr) {
-  if (!__dfsan_get_track_origins())
+  if (!dfsan_get_track_origins())
     return 0;
 
   const dfsan_label label = *__dfsan::shadow_for(addr);
@@ -829,7 +830,7 @@ void dfsan_clear_thread_local_state() {
   internal_memset(__dfsan_arg_tls, 0, sizeof(__dfsan_arg_tls));
   internal_memset(__dfsan_retval_tls, 0, sizeof(__dfsan_retval_tls));
 
-  if (__dfsan_get_track_origins()) {
+  if (dfsan_get_track_origins()) {
     internal_memset(__dfsan_arg_origin_tls, 0, sizeof(__dfsan_arg_origin_tls));
     internal_memset(&__dfsan_retval_origin_tls, 0,
                     sizeof(__dfsan_retval_origin_tls));
@@ -995,7 +996,7 @@ static void DFsanInit(int argc, char **argv, char **envp) {
 
   CheckASLR();
 
-  InitShadow(__dfsan_get_track_origins());
+  InitShadow(dfsan_get_track_origins());
 
   initialize_interceptors();
 

diff --git a/compiler-rt/lib/dfsan/done_abilist.txt b/compiler-rt/lib/dfsan/done_abilist.txt
index ca26eab..111c7d5 100644 (file)
--- a/compiler-rt/lib/dfsan/done_abilist.txt
+++ b/compiler-rt/lib/dfsan/done_abilist.txt
@@ -38,7 +38,8 @@ fun:dfsan_get_origin=uninstrumented
 fun:dfsan_get_origin=custom
 fun:dfsan_get_init_origin=uninstrumented
 fun:dfsan_get_init_origin=discard
-
+fun:dfsan_get_track_origins=uninstrumented
+fun:dfsan_get_track_origins=discard
 
 ###############################################################################
 # glibc

diff --git a/compiler-rt/test/dfsan/dfsan_get_track_origins.c b/compiler-rt/test/dfsan/dfsan_get_track_origins.c
new file mode 100644 (file)
index 0000000..4013fed
--- /dev/null
+++ b/compiler-rt/test/dfsan/dfsan_get_track_origins.c
@@ -0,0 +1,13 @@
+// RUN: %clang_dfsan -DTRACK_ORIGINS=2 -mllvm -dfsan-track-origins=2 %s -o %t && %run %t
+// RUN: %clang_dfsan -DTRACK_ORIGINS=1 -mllvm -dfsan-track-origins=1 %s -o %t && %run %t
+// RUN: %clang_dfsan -DTRACK_ORIGINS=0 %s -o %t && %run %t
+//
+// REQUIRES: x86_64-target-arch
+
+#include <sanitizer/dfsan_interface.h>
+
+#include <assert.h>
+
+int main(int argc, char *argv[]) {
+  assert(dfsan_get_track_origins() == TRACK_ORIGINS);
+}

diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
index 6588c88..63aa84e 100644 (file)
--- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -1397,7 +1397,8 @@ bool DataFlowSanitizer::runImpl(Module &M) {
     Changed = true;
     return new GlobalVariable(
         M, OriginTy, true, GlobalValue::WeakODRLinkage,
-        ConstantInt::getSigned(OriginTy, shouldTrackOrigins()),
+        ConstantInt::getSigned(OriginTy,
+                               shouldTrackOrigins() ? ClTrackOrigins : 0),
         "__dfsan_track_origins");
   });
 

diff --git a/llvm/test/Instrumentation/DataFlowSanitizer/basic.ll b/llvm/test/Instrumentation/DataFlowSanitizer/basic.ll
index 40e63f6..8f11036 100644 (file)
--- a/llvm/test/Instrumentation/DataFlowSanitizer/basic.ll
+++ b/llvm/test/Instrumentation/DataFlowSanitizer/basic.ll
@@ -1,5 +1,6 @@
 ; RUN: opt < %s -dfsan -S | FileCheck %s --check-prefixes=CHECK,CHECK_NO_ORIGIN -DSHADOW_XOR_MASK=87960930222080 --dump-input-context=100
-; RUN: opt < %s -dfsan -dfsan-track-origins=1  -S | FileCheck %s --check-prefixes=CHECK,CHECK_ORIGIN -DSHADOW_XOR_MASK=87960930222080 --dump-input-context=100
+; RUN: opt < %s -dfsan -dfsan-track-origins=1  -S | FileCheck %s --check-prefixes=CHECK,CHECK_ORIGIN1 -DSHADOW_XOR_MASK=87960930222080 --dump-input-context=100
+; RUN: opt < %s -dfsan -dfsan-track-origins=2  -S | FileCheck %s --check-prefixes=CHECK_ORIGIN2 -DSHADOW_XOR_MASK=87960930222080 --dump-input-context=100
 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"
 
@@ -8,7 +9,8 @@ target triple = "x86_64-unknown-linux-gnu"
 ; CHECK: @__dfsan_arg_origin_tls = external thread_local(initialexec) global [200 x i32]
 ; CHECK: @__dfsan_retval_origin_tls = external thread_local(initialexec) global i32
 ; CHECK_NO_ORIGIN: @__dfsan_track_origins = weak_odr constant i32 0
-; CHECK_ORIGIN: @__dfsan_track_origins = weak_odr constant i32 1
+; CHECK_ORIGIN1: @__dfsan_track_origins = weak_odr constant i32 1
+; CHECK_ORIGIN2: @__dfsan_track_origins = weak_odr constant i32 2
 ; CHECK: @__dfsan_shadow_width_bits = weak_odr constant i32 [[#SBITS:]]
 ; CHECK: @__dfsan_shadow_width_bytes = weak_odr constant i32 [[#SBYTES:]]