diff options
Diffstat (limited to 'osdep/subprocess-posix.c')
| -rw-r--r-- | osdep/subprocess-posix.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/osdep/subprocess-posix.c b/osdep/subprocess-posix.c index bae0ca2c78..c75d267cdd 100644 --- a/osdep/subprocess-posix.c +++ b/osdep/subprocess-posix.c @@ -16,7 +16,6 @@ */ #include <poll.h> -#include <pthread.h> #include <unistd.h> #include <sys/types.h> #include <sys/wait.h> @@ -33,6 +32,12 @@ extern char **environ; +#ifdef SIGRTMAX +#define SIGNAL_MAX SIGRTMAX +#else +#define SIGNAL_MAX 32 +#endif + #define SAFE_CLOSE(fd) do { if ((fd) >= 0) close((fd)); (fd) = -1; } while (0) // Async-signal-safe execvpe(). POSIX does not list it as async-signal-safe @@ -65,6 +70,20 @@ static int as_execvpe(const char *path, const char *file, char *const argv[], return -1; } +// In the child process, resets the signal mask to defaults. Also clears any +// signal handlers first so nothing funny happens. +static void reset_signals_child(void) +{ + struct sigaction sa = { 0 }; + sigset_t sigmask; + sa.sa_handler = SIG_DFL; + sigemptyset(&sigmask); + + for (int nr = 1; nr < SIGNAL_MAX; nr++) + sigaction(nr, &sa, NULL); + sigprocmask(SIG_SETMASK, &sigmask, NULL); +} + // Returns 0 on any error, valid PID on success. // This function must be async-signal-safe, as it may be called from a fork(). static pid_t spawn_process(const char *path, struct mp_subprocess_opts *opts, @@ -96,6 +115,7 @@ static pid_t spawn_process(const char *path, struct mp_subprocess_opts *opts, } if (fres == 0) { // child + reset_signals_child(); for (int n = 0; n < opts->num_fds; n++) { if (src_fds[n] == opts->fds[n].fd) { @@ -113,7 +133,7 @@ static pid_t spawn_process(const char *path, struct mp_subprocess_opts *opts, as_execvpe(path, opts->exe, opts->args, opts->env ? opts->env : environ); child_failed: - write(p[1], &(char){1}, 1); // shouldn't be able to fail + (void)write(p[1], &(char){1}, 1); // shouldn't be able to fail _exit(1); } @@ -261,7 +281,7 @@ void mp_subprocess2(struct mp_subprocess_opts *opts, if (pid) kill(pid, SIGKILL); killed_by_us = true; - break; + goto break_poll; } struct mp_subprocess_fd *fd = &opts->fds[n]; if (fd->on_read) { @@ -296,6 +316,8 @@ void mp_subprocess2(struct mp_subprocess_opts *opts, } } +break_poll: + // Note: it can happen that a child process closes the pipe, but does not // terminate yet. In this case, we would have to run waitpid() in // a separate thread and use pthread_cancel(), or use other weird |