diff options
Diffstat (limited to 'executor')
| -rw-r--r-- | executor/executor.cc | 113 |
1 files changed, 83 insertions, 30 deletions
diff --git a/executor/executor.cc b/executor/executor.cc index e126d466d..2c2aa9841 100644 --- a/executor/executor.cc +++ b/executor/executor.cc @@ -11,11 +11,14 @@ #include <unistd.h> #include <fcntl.h> #include <time.h> +#include <signal.h> +#include <limits.h> #include <sys/types.h> #include <sys/time.h> #include <sys/syscall.h> #include <sys/stat.h> #include <sys/mman.h> +#include <sys/wait.h> #include <linux/futex.h> #include <pthread.h> #include <grp.h> @@ -24,6 +27,8 @@ const int kInFd = 3; const int kOutFd = 4; +const int kInPipeFd = 5; +const int kOutPipeFd = 6; const int kCoverFd = 5; const int kMaxInput = 1 << 20; const int kMaxOutput = 16 << 20; @@ -39,6 +44,9 @@ const uint64_t arg_const = 0; const uint64_t arg_result = 1; const uint64_t arg_data = 2; +const int kFailStatus = 67; +const int kErrorStatus = 68; + // We use the default value instead of results of failed syscalls. // -1 is an invalid fd and an invalid address and deterministic, // so good enough for our purposes. @@ -89,6 +97,7 @@ __attribute__((noreturn)) void fail(const char* msg, ...); __attribute__((noreturn)) void error(const char* msg, ...); __attribute__((noreturn)) void exitf(const char* msg, ...); void debug(const char* msg, ...); +void execute_one(); uint64_t read_input(uint64_t** input_posp, bool peek = false); uint64_t read_arg(uint64_t** input_posp); uint64_t read_result(uint64_t** input_posp); @@ -112,35 +121,84 @@ int main() fail("mmap of input file failed"); if (mmap(&output_data[0], kMaxOutput, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, kOutFd, 0) != &output_data[0]) fail("mmap of output file failed"); -retry: - uint64_t* input_pos = (uint64_t*)&input_data[0]; - uint64_t flags = read_input(&input_pos); + char cwdbuf[64 << 10]; + char* cwd = getcwd(cwdbuf, sizeof(cwdbuf)); + + sigset_t sigchldset; + sigemptyset(&sigchldset); + sigaddset(&sigchldset, SIGCHLD); + if (sigprocmask(SIG_BLOCK, &sigchldset, NULL)) + fail("sigprocmask failed"); + + uint64_t flags = *(uint64_t*)input_data; flag_debug = flags & (1 << 0); flag_cover = flags & (1 << 1); flag_threaded = flags & (1 << 2); flag_collide = flags & (1 << 3); flag_deduplicate = flags & (1 << 4); flag_drop_privs = flags & (1 << 5); - output_pos = (uint32_t*)&output_data[0]; - write_output(0); // Number of executed syscalls (updated later). - if (flag_collide) flag_threaded = true; - if (!collide) { - cover_open(); - if (!flag_threaded) - cover_init(&threads[0]); - - if (flag_drop_privs) { - // TODO: 65534 is meant to be nobody - if (setgroups(0, NULL)) - fail("failed to setgroups"); - if (setresgid(65534, 65534, 65534)) - fail("failed to setresgid"); - if (setresuid(65534, 65534, 65534)) - fail("failed to setresuid"); + + cover_open(); + + for (;;) { + char tmp; + if (read(kInPipeFd, &tmp, 1) != 1) + fail("control pipe read failed"); + // The dir may have been recreated. + if (chdir(cwd)) + fail("failed to chdir"); + + int pid = fork(); + if (pid < 0) + fail("fork failed"); + if (pid == 0) { + setpgid(0, 0); + if (flag_drop_privs) { + // TODO: 65534 is meant to be nobody + if (setgroups(0, NULL)) + fail("failed to setgroups"); + if (setresgid(65534, 65534, 65534)) + fail("failed to setresgid"); + if (setresuid(65534, 65534, 65534)) + fail("failed to setresuid"); + } + execute_one(); + debug("exiting\n"); + return 0; } + + timespec ts = {}; + ts.tv_sec = 5; + ts.tv_nsec = 0; + if (sigtimedwait(&sigchldset, NULL, &ts) < 0) { + kill(-pid, SIGKILL); + kill(pid, SIGKILL); + } + int status = 0; + if (waitpid(pid, &status, 0) != pid) + fail("waitpid failed"); + status = WEXITSTATUS(status); + if (status == kFailStatus) + fail("child failed"); + if (status == kErrorStatus) + error("child errored"); + if (write(kOutPipeFd, &tmp, 1) != 1) + fail("control pipe write failed"); } +} + +void execute_one() +{ +retry: + uint64_t* input_pos = (uint64_t*)&input_data[0]; + read_input(&input_pos); // flags + output_pos = (uint32_t*)&output_data[0]; + write_output(0); // Number of executed syscalls (updated later). + + if (!collide && !flag_threaded) + cover_init(&threads[0]); int call_index = 0; for (int n = 0;; n++) { @@ -236,16 +294,11 @@ retry: } } - if (flag_collide) { - if (!collide) { - debug("enabling collider\n"); - collide = true; - goto retry; - } + if (flag_collide && !collide) { + debug("enabling collider\n"); + collide = true; + goto retry; } - - debug("exiting\n"); - return 0; } thread_t* schedule_call(int n, int call_index, int call_num, uint64_t num_args, uint64_t* args, uint64_t* pos) @@ -537,7 +590,7 @@ void fail(const char* msg, ...) vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); - exit(67); + exit(kFailStatus); } // kernel error (e.g. wrong syscall return value) @@ -549,7 +602,7 @@ void error(const char* msg, ...) vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, "\n"); - exit(68); + exit(kErrorStatus); } // just exit (e.g. due to temporal ENOMEM error) |