<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Jan 27, 2016 at 4:37 PM, Evgeniy Stepanov via llvm-commits <span dir="ltr"><<a href="mailto:llvm-commits@lists.llvm.org" target="_blank">llvm-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: eugenis<br>
Date: Wed Jan 27 18:37:54 2016<br>
New Revision: 259007<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=259007&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=259007&view=rev</a><br>
Log:<br>
[cfi] Fix recovery from out-of-bounds vtable error.<br>
<br>
Modified:<br>
    compiler-rt/trunk/lib/cfi/cfi.cc<br>
    compiler-rt/trunk/test/cfi/cross-dso/target_out_of_bounds.cpp<br>
<br>
Modified: compiler-rt/trunk/lib/cfi/cfi.cc<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/cfi/cfi.cc?rev=259007&r1=259006&r2=259007&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/cfi/cfi.cc?rev=259007&r1=259006&r2=259007&view=diff</a><br>
==============================================================================<br>
--- compiler-rt/trunk/lib/cfi/cfi.cc (original)<br>
+++ compiler-rt/trunk/lib/cfi/cfi.cc Wed Jan 27 18:37:54 2016<br>
@@ -306,12 +306,14 @@ ALWAYS_INLINE void CfiSlowPathCommon(u64<br>
     // FIXME: call the ubsan handler if DiagData != nullptr?<br>
     VReport(1, "CFI: invalid memory region for a check target: %p\n", Ptr);<br>
 #ifdef CFI_ENABLE_DIAG<br>
-    if (DiagData)<br>
+    if (DiagData) {<br>
       __ubsan_handle_cfi_check_fail(<br>
           reinterpret_cast<__ubsan::CFICheckFailData *>(DiagData),<br>
           reinterpret_cast<uptr>(Ptr));<br>
-    else<br>
+      return;<br>
+    } else {<br></blockquote><div><br></div><div>Drop the else-after-return, and possibly invert to reduce indentation:<br><br>  if (!DiagData)<br>    Trap();<br>  __ubsaN-handle_...</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
       Trap();<br>
+    }<br>
 #else<br>
     Trap();<br>
 #endif<br>
@@ -348,7 +350,8 @@ void InitializeFlags() {<br>
<br>
   SetVerbosity(common_flags()->verbosity);<br>
<br>
-  if (Verbosity()) ReportUnrecognizedFlags();<br>
+  if (Verbosity())<br>
+    ReportUnrecognizedFlags();<br>
<br>
   if (common_flags()->help) {<br>
     cfi_parser.PrintFlagDescriptions();<br>
<br>
Modified: compiler-rt/trunk/test/cfi/cross-dso/target_out_of_bounds.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/cfi/cross-dso/target_out_of_bounds.cpp?rev=259007&r1=259006&r2=259007&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/cfi/cross-dso/target_out_of_bounds.cpp?rev=259007&r1=259006&r2=259007&view=diff</a><br>
==============================================================================<br>
--- compiler-rt/trunk/test/cfi/cross-dso/target_out_of_bounds.cpp (original)<br>
+++ compiler-rt/trunk/test/cfi/cross-dso/target_out_of_bounds.cpp Wed Jan 27 18:37:54 2016<br>
@@ -20,9 +20,13 @@ int main(int argc, char *argv[]) {<br>
   // enough to handle unaddressable vtables. TODO: fix this.<br>
   void *empty = calloc(1, 128);<br>
   uintptr_t v = (uintptr_t)empty + 64;<br>
-  A *volatile p = new A();<br>
-  for (uintptr_t *q = (uintptr_t *)p; q < (uintptr_t *)(p + 1); ++q)<br>
+  char *volatile p = reinterpret_cast<char *>(new A());<br>
+  for (uintptr_t *q = (uintptr_t *)p; q < (uintptr_t *)(p + sizeof(A)); ++q)<br>
     *q = v;<br>
+<br>
+  // CHECK: runtime error: control flow integrity check for type 'A' failed during cast<br>
+  A *volatile pa = reinterpret_cast<A *>(p);<br>
+<br>
   // CHECK: untime error: control flow integrity check for type 'A' failed during virtual call<br>
-  p->f();<br>
+  pa->f();<br>
 }<br>
<br>
<br>
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</blockquote></div><br></div></div>