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//===- FuzzerUtilFuchsia.cpp - Misc utils for Fuchsia. --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// Misc utils implementation using Fuchsia/Zircon APIs.
//===----------------------------------------------------------------------===//
#include "FuzzerDefs.h"
#if LIBFUZZER_FUCHSIA
#include "FuzzerInternal.h"
#include "FuzzerUtil.h"
#include <cerrno>
#include <cinttypes>
#include <cstdint>
#include <fbl/unique_fd.h>
#include <fcntl.h>
#include <launchpad/launchpad.h>
#include <string>
#include <thread>
#include <zircon/errors.h>
#include <zircon/status.h>
#include <zircon/syscalls.h>
#include <zircon/syscalls/port.h>
#include <zircon/types.h>
#include <zx/object.h>
#include <zx/port.h>
#include <zx/process.h>
#include <zx/time.h>
namespace fuzzer {
namespace {
// A magic value for the Zircon exception port, chosen to spell 'FUZZING'
// when interpreted as a byte sequence on little-endian platforms.
const uint64_t kFuzzingCrash = 0x474e495a5a5546;
void AlarmHandler(int Seconds) {
while (true) {
SleepSeconds(Seconds);
Fuzzer::StaticAlarmCallback();
}
}
void InterruptHandler() {
// Ctrl-C sends ETX in Zircon.
while (getchar() != 0x03);
Fuzzer::StaticInterruptCallback();
}
void CrashHandler(zx::port *Port) {
std::unique_ptr<zx::port> ExceptionPort(Port);
zx_port_packet_t Packet;
ExceptionPort->wait(ZX_TIME_INFINITE, &Packet, 0);
// Unbind as soon as possible so we don't receive exceptions from this thread.
if (zx_task_bind_exception_port(ZX_HANDLE_INVALID, ZX_HANDLE_INVALID,
kFuzzingCrash, 0) != ZX_OK) {
// Shouldn't happen; if it does the safest option is to just exit.
Printf("libFuzzer: unable to unbind exception port; aborting!\n");
exit(1);
}
if (Packet.key != kFuzzingCrash) {
Printf("libFuzzer: invalid crash key: %" PRIx64 "; aborting!\n",
Packet.key);
exit(1);
}
// CrashCallback should not return from this call
Fuzzer::StaticCrashSignalCallback();
}
} // namespace
// Platform specific functions.
void SetSignalHandler(const FuzzingOptions &Options) {
zx_status_t rc;
// Set up alarm handler if needed.
if (Options.UnitTimeoutSec > 0) {
std::thread T(AlarmHandler, Options.UnitTimeoutSec / 2 + 1);
T.detach();
}
// Set up interrupt handler if needed.
if (Options.HandleInt || Options.HandleTerm) {
std::thread T(InterruptHandler);
T.detach();
}
// Early exit if no crash handler needed.
if (!Options.HandleSegv && !Options.HandleBus && !Options.HandleIll &&
!Options.HandleFpe && !Options.HandleAbrt)
return;
// Create an exception port
zx::port *ExceptionPort = new zx::port();
if ((rc = zx::port::create(0, ExceptionPort)) != ZX_OK) {
Printf("libFuzzer: zx_port_create failed: %s\n", zx_status_get_string(rc));
exit(1);
}
// Bind the port to receive exceptions from our process
if ((rc = zx_task_bind_exception_port(zx_process_self(), ExceptionPort->get(),
kFuzzingCrash, 0)) != ZX_OK) {
Printf("libFuzzer: unable to bind exception port: %s\n",
zx_status_get_string(rc));
exit(1);
}
// Set up the crash handler.
std::thread T(CrashHandler, ExceptionPort);
T.detach();
}
void SleepSeconds(int Seconds) {
zx::nanosleep(zx::deadline_after(ZX_SEC(Seconds)));
}
unsigned long GetPid() {
zx_status_t rc;
zx_info_handle_basic_t Info;
if ((rc = zx_object_get_info(zx_process_self(), ZX_INFO_HANDLE_BASIC, &Info,
sizeof(Info), NULL, NULL)) != ZX_OK) {
Printf("libFuzzer: unable to get info about self: %s\n",
zx_status_get_string(rc));
exit(1);
}
return Info.koid;
}
size_t GetPeakRSSMb() {
zx_status_t rc;
zx_info_task_stats_t Info;
if ((rc = zx_object_get_info(zx_process_self(), ZX_INFO_TASK_STATS, &Info,
sizeof(Info), NULL, NULL)) != ZX_OK) {
Printf("libFuzzer: unable to get info about self: %s\n",
zx_status_get_string(rc));
exit(1);
}
return (Info.mem_private_bytes + Info.mem_shared_bytes) >> 20;
}
int ExecuteCommand(const Command &Cmd) {
zx_status_t rc;
// Convert arguments to C array
auto Args = Cmd.getArguments();
size_t Argc = Args.size();
assert(Argc != 0);
std::unique_ptr<const char *[]> Argv(new const char *[Argc]);
for (size_t i = 0; i < Argc; ++i)
Argv[i] = Args[i].c_str();
// Create the basic launchpad. Clone everything except stdio.
launchpad_t *lp;
launchpad_create(ZX_HANDLE_INVALID, Argv[0], &lp);
launchpad_load_from_file(lp, Argv[0]);
launchpad_set_args(lp, Argc, Argv.get());
launchpad_clone(lp, LP_CLONE_ALL & (~LP_CLONE_FDIO_STDIO));
// Determine stdout
int FdOut = STDOUT_FILENO;
fbl::unique_fd OutputFile;
if (Cmd.hasOutputFile()) {
auto Filename = Cmd.getOutputFile();
OutputFile.reset(open(Filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0));
if (!OutputFile) {
Printf("libFuzzer: failed to open %s: %s\n", Filename.c_str(),
strerror(errno));
return ZX_ERR_IO;
}
FdOut = OutputFile.get();
}
// Determine stderr
int FdErr = STDERR_FILENO;
if (Cmd.isOutAndErrCombined())
FdErr = FdOut;
// Clone the file descriptors into the new process
if ((rc = launchpad_clone_fd(lp, STDIN_FILENO, STDIN_FILENO)) != ZX_OK ||
(rc = launchpad_clone_fd(lp, FdOut, STDOUT_FILENO)) != ZX_OK ||
(rc = launchpad_clone_fd(lp, FdErr, STDERR_FILENO)) != ZX_OK) {
Printf("libFuzzer: failed to clone FDIO: %s\n", zx_status_get_string(rc));
return rc;
}
// Start the process
zx_handle_t ProcessHandle = ZX_HANDLE_INVALID;
const char *ErrorMsg = nullptr;
if ((rc = launchpad_go(lp, &ProcessHandle, &ErrorMsg)) != ZX_OK) {
Printf("libFuzzer: failed to launch '%s': %s, %s\n", Argv[0], ErrorMsg,
zx_status_get_string(rc));
return rc;
}
zx::process Process(ProcessHandle);
// Now join the process and return the exit status.
if ((rc = Process.wait_one(ZX_PROCESS_TERMINATED, ZX_TIME_INFINITE,
nullptr)) != ZX_OK) {
Printf("libFuzzer: failed to join '%s': %s\n", Argv[0],
zx_status_get_string(rc));
return rc;
}
zx_info_process_t Info;
if ((rc = Process.get_info(ZX_INFO_PROCESS, &Info, sizeof(Info), nullptr,
nullptr)) != ZX_OK) {
Printf("libFuzzer: unable to get return code from '%s': %s\n", Argv[0],
zx_status_get_string(rc));
return rc;
}
return Info.return_code;
}
const void *SearchMemory(const void *Data, size_t DataLen, const void *Patt,
size_t PattLen) {
return memmem(Data, DataLen, Patt, PattLen);
}
} // namespace fuzzer
#endif // LIBFUZZER_FUCHSIA
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