From 079b7657767dcc0fb284225c277d2b9ce73e423b Mon Sep 17 00:00:00 2001 From: Vedant Kumar Date: Mon, 12 Jun 2017 18:42:51 +0000 Subject: [ubsan] Detect invalid unsigned pointer index expression (compiler-rt) Compiler-rt part of: https://reviews.llvm.org/D33910 Differential Revision: https://reviews.llvm.org/D33911 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@305217 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/ubsan/ubsan_handlers.cc | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'lib/ubsan/ubsan_handlers.cc') diff --git a/lib/ubsan/ubsan_handlers.cc b/lib/ubsan/ubsan_handlers.cc index 80cc8ad25..5dabbd8e0 100644 --- a/lib/ubsan/ubsan_handlers.cc +++ b/lib/ubsan/ubsan_handlers.cc @@ -566,8 +566,14 @@ static void handlePointerOverflowImpl(PointerOverflowData *Data, ScopedReport R(Opts, Loc, ET); - Diag(Loc, DL_Error, "pointer index expression with base %0 overflowed to %1") - << (void *)Base << (void*)Result; + if ((sptr(Base) >= 0) == (sptr(Result) >= 0)) + Diag(Loc, DL_Error, "unsigned pointer index expression result is %0, " + "preceding its base %1") + << (void *)Result << (void *)Base; + else + Diag(Loc, DL_Error, + "pointer index expression with base %0 overflowed to %1") + << (void *)Base << (void *)Result; } void __ubsan::__ubsan_handle_pointer_overflow(PointerOverflowData *Data, -- cgit v1.2.3