From 2f65e506ec18c7d9c683b6042e0d2d93f5afa78d Mon Sep 17 00:00:00 2001 From: Jake Ehrlich Date: Fri, 11 Oct 2019 23:35:13 +0000 Subject: [libFuzzer] Don't prefix absolute paths in fuchsia. The ExecuteCommand function in fuchsia used to prefix the getOutputFile for each command run with the artifact_prefix flag if it was available, because fuchsia components don't have a writable working directory. However, if a file with a global path is provided, fuchsia should honor that. An example of this is using the global /tmp directory to store stuff. In fuchsia it ended up being translated to data///tmp, whereas we want to make sure it is using /tmp (which is available to components using the isolated-temp feature). To test this I made the change, compiled fuchsia with this toolchain and ran a fuzzer with the -fork=1 flag (that mode makes use of the /tmp directory). I also tested that normal fuzzing workflow was not affected by this. Author: charco (Marco Vanotti) Differential Revision: https://reviews.llvm.org/D68774 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@374612 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/fuzzer/FuzzerUtilFuchsia.cpp | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/lib/fuzzer/FuzzerUtilFuchsia.cpp b/lib/fuzzer/FuzzerUtilFuchsia.cpp index 50071a7e5..79fd950bb 100644 --- a/lib/fuzzer/FuzzerUtilFuchsia.cpp +++ b/lib/fuzzer/FuzzerUtilFuchsia.cpp @@ -407,13 +407,14 @@ int ExecuteCommand(const Command &Cmd) { // that lacks a mutable working directory. Fortunately, when this is the case // a mutable output directory must be specified using "-artifact_prefix=...", // so write the log file(s) there. + // However, we don't want to apply this logic for absolute paths. int FdOut = STDOUT_FILENO; if (Cmd.hasOutputFile()) { - std::string Path; - if (Cmd.hasFlag("artifact_prefix")) - Path = Cmd.getFlagValue("artifact_prefix") + "/" + Cmd.getOutputFile(); - else - Path = Cmd.getOutputFile(); + std::string Path = Cmd.getOutputFile(); + bool IsAbsolutePath = Path.length() > 1 && Path[0] == '/'; + if (!IsAbsolutePath && Cmd.hasFlag("artifact_prefix")) + Path = Cmd.getFlagValue("artifact_prefix") + "/" + Path; + FdOut = open(Path.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0); if (FdOut == -1) { Printf("libFuzzer: failed to open %s: %s\n", Path.c_str(), -- cgit v1.2.1