1 files changed, 74 insertions, 37 deletions
diff --git a/compiler-rt/include/sanitizer/dfsan_interface.h b/compiler-rt/include/sanitizer/dfsan_interface.h
index 18b2c81a6023..cd3b6d6e2b16 100644
--- a/compiler-rt/include/sanitizer/dfsan_interface.h
+++ b/compiler-rt/include/sanitizer/dfsan_interface.h
@@ -21,33 +21,15 @@
 extern "C" {
 #endif
 
-typedef uint16_t dfsan_label;
-
-/// Stores information associated with a specific label identifier.  A label
-/// may be a base label created using dfsan_create_label, with associated
-/// text description and user data, or an automatically created union label,
-/// which represents the union of two label identifiers (which may themselves
-/// be base or union labels).
-struct dfsan_label_info {
-  // Fields for union labels, set to 0 for base labels.
-  dfsan_label l1;
-  dfsan_label l2;
-
-  // Fields for base labels.
-  const char *desc;
-  void *userdata;
-};
+typedef uint8_t dfsan_label;
+typedef uint32_t dfsan_origin;
 
 /// Signature of the callback argument to dfsan_set_write_callback().
 typedef void (*dfsan_write_callback_t)(int fd, const void *buf, size_t count);
 
-/// Computes the union of \c l1 and \c l2, possibly creating a union label in
-/// the process.
+/// Computes the union of \c l1 and \c l2, resulting in a union label.
 dfsan_label dfsan_union(dfsan_label l1, dfsan_label l2);
 
-/// Creates and returns a base label with the given description and user data.
-dfsan_label dfsan_create_label(const char *desc, void *userdata);
-
 /// Sets the label for each address in [addr,addr+size) to \c label.
 void dfsan_set_label(dfsan_label label, void *addr, size_t size);
 
@@ -63,22 +45,18 @@ void dfsan_add_label(dfsan_label label, void *addr, size_t size);
 /// value.
 dfsan_label dfsan_get_label(long data);
 
+/// Retrieves the immediate origin associated with the given data. The returned
+/// origin may point to another origin.
+///
+/// The type of 'data' is arbitrary.
+dfsan_origin dfsan_get_origin(long data);
+
 /// Retrieves the label associated with the data at the given address.
 dfsan_label dfsan_read_label(const void *addr, size_t size);
 
-/// Retrieves a pointer to the dfsan_label_info struct for the given label.
-const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label);
-
 /// Returns whether the given label label contains the label elem.
 int dfsan_has_label(dfsan_label label, dfsan_label elem);
 
-/// If the given label label contains a label with the description desc, returns
-/// that label, else returns 0.
-dfsan_label dfsan_has_label_with_desc(dfsan_label label, const char *desc);
-
-/// Returns the number of labels allocated.
-size_t dfsan_get_label_count(void);
-
 /// Flushes the DFSan shadow, i.e. forgets about all labels currently associated
 /// with the application memory.  Use this call to start over the taint tracking
 /// within the same process.
@@ -92,12 +70,6 @@ void dfsan_flush(void);
 /// callback executes.  Pass in NULL to remove any callback.
 void dfsan_set_write_callback(dfsan_write_callback_t labeled_write_callback);
 
-/// Writes the labels currently used by the program to the given file
-/// descriptor. The lines of the output have the following format:
-///
-/// <label> <parent label 1> <parent label 2> <label description if any>
-void dfsan_dump_labels(int fd);
-
 /// Interceptor hooks.
 /// Whenever a dfsan's custom function is called the corresponding
 /// hook is called it non-zero. The hooks should be defined by the user.
@@ -110,6 +82,71 @@ void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2,
 void dfsan_weak_hook_strncmp(void *caller_pc, const char *s1, const char *s2,
                              size_t n, dfsan_label s1_label,
                              dfsan_label s2_label, dfsan_label n_label);
+
+/// Prints the origin trace of the label at the address addr to stderr. It also
+/// prints description at the beginning of the trace. If origin tracking is not
+/// on, or the address is not labeled, it prints nothing.
+void dfsan_print_origin_trace(const void *addr, const char *description);
+
+/// Prints the origin trace of the label at the address \p addr to a
+/// pre-allocated output buffer. If origin tracking is not on, or the address is
+/// not labeled, it prints nothing.
+///
+/// Typical usage:
+/// \code
+///   char kDescription[] = "...";
+///   char buf[1024];
+///   dfsan_sprint_origin_trace(&tainted_var, kDescription, buf, sizeof(buf));
+/// \endcode
+///
+/// Typical usage that handles truncation:
+/// \code
+///   char buf[1024];
+///   int len = dfsan_sprint_origin_trace(&var, nullptr, buf, sizeof(buf));
+///
+///   if (len < sizeof(buf)) {
+///     ProcessOriginTrace(buf);
+///   } else {
+///     char *tmpbuf = new char[len + 1];
+///     dfsan_sprint_origin_trace(&var, nullptr, tmpbuf, len + 1);
+///     ProcessOriginTrace(tmpbuf);
+///     delete[] tmpbuf;
+///   }
+/// \endcode
+///
+/// \param addr The tainted memory address whose origin we are printing.
+/// \param description A description printed at the beginning of the trace.
+/// \param [out] out_buf The output buffer to write the results to.
+/// \param out_buf_size The size of \p out_buf.
+///
+/// \returns The number of symbols that should have been written to \p out_buf
+/// (not including trailing null byte '\0'). Thus, the string is truncated iff
+/// return value is not less than \p out_buf_size.
+size_t dfsan_sprint_origin_trace(const void *addr, const char *description,
+                                 char *out_buf, size_t out_buf_size);
+
+/// Prints the stack trace leading to this call to a pre-allocated output
+/// buffer.
+///
+/// For usage examples, see dfsan_sprint_origin_trace.
+///
+/// \param [out] out_buf The output buffer to write the results to.
+/// \param out_buf_size The size of \p out_buf.
+///
+/// \returns The number of symbols that should have been written to \p out_buf
+/// (not including trailing null byte '\0'). Thus, the string is truncated iff
+/// return value is not less than \p out_buf_size.
+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"