commit 29832ba023cb9ef0b42fd71c6b573f5f21bd4d24
author Vitaly Buka <vitalybuka@google.com> Fri Apr 05 20:17:03 2019 +0000
committer Copybara-Service <copybara-worker@google.com> Thu Mar 25 23:19:21 2021 -0700
tree 087a3d72da0cbe60c46a1f9006e56eefbe87b56f
parent ad682a85899e411d3a10353cf32bf48c0852df57

Use binary write mode in WriteToFile function to avoid appended \r characters on Windows

Summary:
When using libfuzzer on Windows, in the contents of a crash sample, bytes that can be mistaken for a \n are replaced by a \r\n sequence. As a consequence, crashes are not reproducible. This patch will open files in binary mode to fix this issue. The patch does not affect POSIX systems.

Patch by tuktuk

Reviewers: kcc, vitalybuka

Reviewed By: vitalybuka

Subscribers: dexonsmith, jdoerfert, llvm-commits, #sanitizers

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D60008

llvm-svn: 357807
GitOrigin-RevId: 3db6ad2bcfc5fb38343cfd7ce6eb56d9415e2b1e

FuzzerIO.cpp

diff --git a/FuzzerIO.cpp b/FuzzerIO.cpp
index 290112a..423ab4b 100644
--- a/FuzzerIO.cpp
+++ b/FuzzerIO.cpp
@@ -62,7 +62,7 @@
 
 void WriteToFile(const Unit &U, const std::string &Path) {
   // Use raw C interface because this function may be called from a sig handler.
-  FILE *Out = fopen(Path.c_str(), "w");
+  FILE *Out = fopen(Path.c_str(), "wb");
   if (!Out) return;
   fwrite(U.data(), sizeof(U[0]), U.size(), Out);
   fclose(Out);