[compiler-rt] e5b603a - [libFuzzer] don't use /dev/null for DiscardOuput in Fuchsia.
Marco Vanotti via llvm-commits
llvm-commits at lists.llvm.org
Thu Nov 21 16:56:20 PST 2019
Author: Marco Vanotti
Date: 2019-11-21T16:56:05-08:00
New Revision: e5b603a4c32044932c3a1d26ccbc7d43fec939d5
URL: https://github.com/llvm/llvm-project/commit/e5b603a4c32044932c3a1d26ccbc7d43fec939d5
DIFF: https://github.com/llvm/llvm-project/commit/e5b603a4c32044932c3a1d26ccbc7d43fec939d5.diff
LOG: [libFuzzer] don't use /dev/null for DiscardOuput in Fuchsia.
Summary:
This commit moves the `DiscardOutput` function in FuzzerIO to
FuzzerUtil, so fuchsia can have its own specialized version.
In fuchsia, accessing `/dev/null` is not supported, and there's nothing
similar to a file that discards everything that is written to it. The
way of doing something similar in fuchsia is by using `fdio_null_create`
and binding that to a file descriptor with `fdio_bind_to_fd`.
This change should fix one of the issues with the `-close_fd_mask` flag
in libfuzzer, in which closing stdout was not working due to
`fopen("/dev/null", "w")` returning `NULL`.
Reviewers: kcc, aarongreen
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D69593
Added:
Modified:
compiler-rt/lib/fuzzer/FuzzerIO.h
compiler-rt/lib/fuzzer/FuzzerIOPosix.cpp
compiler-rt/lib/fuzzer/FuzzerIOWindows.cpp
compiler-rt/lib/fuzzer/FuzzerUtil.h
compiler-rt/lib/fuzzer/FuzzerUtilDarwin.cpp
compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp
compiler-rt/lib/fuzzer/FuzzerUtilLinux.cpp
compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp
Removed:
################################################################################
diff --git a/compiler-rt/lib/fuzzer/FuzzerIO.h b/compiler-rt/lib/fuzzer/FuzzerIO.h
index fe0d7b451758..ae8dd24e373c 100644
--- a/compiler-rt/lib/fuzzer/FuzzerIO.h
+++ b/compiler-rt/lib/fuzzer/FuzzerIO.h
@@ -94,8 +94,6 @@ int DuplicateFile(int Fd);
void RemoveFile(const std::string &Path);
void RenameFile(const std::string &OldPath, const std::string &NewPath);
-void DiscardOutput(int Fd);
-
intptr_t GetHandleFromFd(int fd);
void MkDir(const std::string &Path);
diff --git a/compiler-rt/lib/fuzzer/FuzzerIOPosix.cpp b/compiler-rt/lib/fuzzer/FuzzerIOPosix.cpp
index cfd69bbc8111..fcd9b8d8b9c7 100644
--- a/compiler-rt/lib/fuzzer/FuzzerIOPosix.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerIOPosix.cpp
@@ -124,14 +124,6 @@ void RenameFile(const std::string &OldPath, const std::string &NewPath) {
rename(OldPath.c_str(), NewPath.c_str());
}
-void DiscardOutput(int Fd) {
- FILE* Temp = fopen("/dev/null", "w");
- if (!Temp)
- return;
- dup2(fileno(Temp), Fd);
- fclose(Temp);
-}
-
intptr_t GetHandleFromFd(int fd) {
return static_cast<intptr_t>(fd);
}
diff --git a/compiler-rt/lib/fuzzer/FuzzerIOWindows.cpp b/compiler-rt/lib/fuzzer/FuzzerIOWindows.cpp
index 510afebef738..56757aa09a37 100644
--- a/compiler-rt/lib/fuzzer/FuzzerIOWindows.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerIOWindows.cpp
@@ -223,14 +223,6 @@ void RenameFile(const std::string &OldPath, const std::string &NewPath) {
rename(OldPath.c_str(), NewPath.c_str());
}
-void DiscardOutput(int Fd) {
- FILE* Temp = fopen("nul", "w");
- if (!Temp)
- return;
- _dup2(_fileno(Temp), Fd);
- fclose(Temp);
-}
-
intptr_t GetHandleFromFd(int fd) {
return _get_osfhandle(fd);
}
diff --git a/compiler-rt/lib/fuzzer/FuzzerUtil.h b/compiler-rt/lib/fuzzer/FuzzerUtil.h
index 85c5571d684f..00ea6550646f 100644
--- a/compiler-rt/lib/fuzzer/FuzzerUtil.h
+++ b/compiler-rt/lib/fuzzer/FuzzerUtil.h
@@ -79,6 +79,8 @@ inline std::pair<std::string, std::string> SplitBefore(std::string X,
return std::make_pair(S.substr(0, Pos), S.substr(Pos));
}
+void DiscardOutput(int Fd);
+
std::string DisassembleCmd(const std::string &FileName);
std::string SearchRegexCmd(const std::string &Regex);
diff --git a/compiler-rt/lib/fuzzer/FuzzerUtilDarwin.cpp b/compiler-rt/lib/fuzzer/FuzzerUtilDarwin.cpp
index 171db23570c4..d449bc248f09 100644
--- a/compiler-rt/lib/fuzzer/FuzzerUtilDarwin.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerUtilDarwin.cpp
@@ -17,6 +17,7 @@
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
+#include <unistd.h>
// There is no header for this on macOS so declare here
extern "C" char **environ;
@@ -156,6 +157,14 @@ int ExecuteCommand(const Command &Cmd) {
return ProcessStatus;
}
+void DiscardOutput(int Fd) {
+ FILE* Temp = fopen("/dev/null", "w");
+ if (!Temp)
+ return;
+ dup2(fileno(Temp), Fd);
+ fclose(Temp);
+}
+
} // namespace fuzzer
#endif // LIBFUZZER_APPLE
diff --git a/compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp b/compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp
index d869c3ec235e..bde9f68d62aa 100644
--- a/compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerUtilFuchsia.cpp
@@ -18,6 +18,7 @@
#include <cinttypes>
#include <cstdint>
#include <fcntl.h>
+#include <lib/fdio/fdio.h>
#include <lib/fdio/spawn.h>
#include <string>
#include <sys/select.h>
@@ -529,6 +530,18 @@ const void *SearchMemory(const void *Data, size_t DataLen, const void *Patt,
return memmem(Data, DataLen, Patt, PattLen);
}
+// In fuchsia, accessing /dev/null is not supported. There's nothing
+// similar to a file that discards everything that is written to it.
+// The way of doing something similar in fuchsia is by using
+// fdio_null_create and binding that to a file descriptor.
+void DiscardOutput(int Fd) {
+ fdio_t *fdio_null = fdio_null_create();
+ if (fdio_null == nullptr) return;
+ int nullfd = fdio_bind_to_fd(fdio_null, -1, 0);
+ if (nullfd < 0) return;
+ dup2(nullfd, Fd);
+}
+
} // namespace fuzzer
#endif // LIBFUZZER_FUCHSIA
diff --git a/compiler-rt/lib/fuzzer/FuzzerUtilLinux.cpp b/compiler-rt/lib/fuzzer/FuzzerUtilLinux.cpp
index d5a15d19f2a9..bf305b45a7e8 100644
--- a/compiler-rt/lib/fuzzer/FuzzerUtilLinux.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerUtilLinux.cpp
@@ -15,6 +15,7 @@
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
+#include <unistd.h>
namespace fuzzer {
@@ -27,6 +28,14 @@ int ExecuteCommand(const Command &Cmd) {
return exit_code;
}
+void DiscardOutput(int Fd) {
+ FILE* Temp = fopen("/dev/null", "w");
+ if (!Temp)
+ return;
+ dup2(fileno(Temp), Fd);
+ fclose(Temp);
+}
+
} // namespace fuzzer
#endif
diff --git a/compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp b/compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp
index ed90044c3f83..527e7dbd1cf6 100644
--- a/compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp
@@ -16,6 +16,7 @@
#include <chrono>
#include <cstring>
#include <errno.h>
+#include <io.h>
#include <iomanip>
#include <signal.h>
#include <stdio.h>
@@ -190,6 +191,14 @@ std::string SearchRegexCmd(const std::string &Regex) {
return "findstr /r \"" + Regex + "\"";
}
+void DiscardOutput(int Fd) {
+ FILE* Temp = fopen("nul", "w");
+ if (!Temp)
+ return;
+ _dup2(_fileno(Temp), Fd);
+ fclose(Temp);
+}
+
} // namespace fuzzer
#endif // LIBFUZZER_WINDOWS
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