executor: simple freebsd executor

2 files changed, 200 insertions, 0 deletions

diff --git a/executor/common_freebsd.h b/executor/common_freebsd.h
new file mode 100644
index 000000000..87daa17ff
--- /dev/null
+++ b/executor/common_freebsd.h
@@ -0,0 +1,100 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// This file is shared between executor and csource package.
+
+#include <unistd.h>
+#if defined(SYZ_EXECUTOR) || defined(SYZ_THREADED) || defined(SYZ_COLLIDE)
+#include <pthread.h>
+#include <stdlib.h>
+#endif
+#if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT))
+#include <errno.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <time.h>
+#endif
+
+#define doexit exit
+#define NORETURN __attribute__((noreturn))
+
+#include "common.h"
+
+#if defined(SYZ_EXECUTOR) || defined(SYZ_HANDLE_SEGV)
+static __thread int skip_segv;
+static __thread jmp_buf segv_env;
+
+static void segv_handler(int sig, siginfo_t* info, void* uctx)
+{
+	// Generated programs can contain bad (unmapped/protected) addresses,
+	// which cause SIGSEGVs during copyin/copyout.
+	// This handler ignores such crashes to allow the program to proceed.
+	// We additionally opportunistically check that the faulty address
+	// is not within executable data region, because such accesses can corrupt
+	// output region and then fuzzer will fail on corrupted data.
+	uintptr_t addr = (uintptr_t)info->si_addr;
+	const uintptr_t prog_start = 1 << 20;
+	const uintptr_t prog_end = 100 << 20;
+	if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && (addr < prog_start || addr > prog_end)) {
+		debug("SIGSEGV on %p, skipping\n", addr);
+		_longjmp(segv_env, 1);
+	}
+	debug("SIGSEGV on %p, exiting\n", addr);
+	doexit(sig);
+	for (;;) {
+	}
+}
+
+static void install_segv_handler()
+{
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = segv_handler;
+	sa.sa_flags = SA_NODEFER | SA_SIGINFO;
+	sigaction(SIGSEGV, &sa, NULL);
+	sigaction(SIGBUS, &sa, NULL);
+}
+
+#define NONFAILING(...)                                              \
+	{                                                            \
+		__atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \
+		if (_setjmp(segv_env) == 0) {                        \
+			__VA_ARGS__;                                 \
+		}                                                    \
+		__atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \
+	}
+#endif
+
+#if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT))
+static uint64_t current_time_ms()
+{
+	struct timespec ts;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &ts))
+		fail("clock_gettime failed");
+	return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
+}
+#endif
+
+#if defined(SYZ_EXECUTOR)
+static void sleep_ms(uint64_t ms)
+{
+	usleep(ms * 1000);
+}
+#endif
+
+#if defined(SYZ_EXECUTOR) || defined(SYZ_FAULT_INJECTION)
+static int inject_fault(int nth)
+{
+	return 0;
+}
+
+static int fault_injected(int fail_fd)
+{
+	return 0;
+}
+#endif
diff --git a/executor/executor_freebsd.cc b/executor/executor_freebsd.cc
new file mode 100644
index 000000000..8435d4465
--- /dev/null
+++ b/executor/executor_freebsd.cc
@@ -0,0 +1,100 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// +build
+
+#define SYZ_EXECUTOR
+#include "common_freebsd.h"
+
+#include "executor_posix.h"
+
+#include "executor.h"
+
+#include "syscalls_freebsd.h"
+
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+char input_data[kMaxInput];
+uint32_t output;
+
+int main(int argc, char** argv)
+{
+	if (argc == 2 && strcmp(argv[1], "version") == 0) {
+		puts("linux " GOARCH " " SYZ_REVISION " " GIT_REVISION);
+		return 0;
+	}
+
+	// Some minimal sandboxing.
+	struct rlimit rlim;
+	rlim.rlim_cur = rlim.rlim_max = 128 << 20;
+	setrlimit(RLIMIT_AS, &rlim);
+	rlim.rlim_cur = rlim.rlim_max = 8 << 20;
+	setrlimit(RLIMIT_MEMLOCK, &rlim);
+	rlim.rlim_cur = rlim.rlim_max = 1 << 20;
+	setrlimit(RLIMIT_FSIZE, &rlim);
+	rlim.rlim_cur = rlim.rlim_max = 1 << 20;
+	setrlimit(RLIMIT_STACK, &rlim);
+	rlim.rlim_cur = rlim.rlim_max = 0;
+	setrlimit(RLIMIT_CORE, &rlim);
+
+	install_segv_handler();
+	int pos = 0;
+	for (;;) {
+		int rv = read(0, input_data + pos, sizeof(input_data) - pos);
+		if (rv < 0)
+			fail("read failed");
+		if (rv == 0)
+			break;
+		pos += rv;
+	}
+	if (pos < 24)
+		fail("truncated input");
+
+	uint64_t flags = *(uint64_t*)input_data;
+	flag_debug = flags & (1 << 0);
+	flag_threaded = flags & (1 << 2);
+	flag_collide = flags & (1 << 3);
+	if (!flag_threaded)
+		flag_collide = false;
+	uint64_t executor_pid = *((uint64_t*)input_data + 2);
+	debug("input %d, threaded=%d collide=%d pid=%llu\n",
+	      pos, flag_threaded, flag_collide, executor_pid);
+
+	execute_one(((uint64_t*)input_data) + 3);
+	return 0;
+}
+
+long execute_syscall(call_t* c, long a0, long a1, long a2, long a3, long a4, long a5, long a6, long a7, long a8)
+{
+	if (c->call)
+		return c->call(a0, a1, a2, a3, a4, a5, a6, a7, a8);
+	return syscall(c->sys_nr, a0, a1, a2, a3, a4, a5);
+}
+
+void cover_open()
+{
+}
+
+void cover_enable(thread_t* th)
+{
+}
+
+void cover_reset(thread_t* th)
+{
+}
+
+uint64_t read_cover_size(thread_t* th)
+{
+	return 0;
+}
+
+uint32_t* write_output(uint32_t v)
+{
+	return &output;
+}
+
+void write_completed(uint32_t completed)
+{
+}