diff options
Diffstat (limited to 'arch/um/os-Linux/sigio.c')
| -rw-r--r-- | arch/um/os-Linux/sigio.c | 128 |
1 files changed, 79 insertions, 49 deletions
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c index 00e9388e947..f6457765b17 100644 --- a/arch/um/os-Linux/sigio.c +++ b/arch/um/os-Linux/sigio.c @@ -43,17 +43,9 @@ struct pollfds { /* Protected by sigio_lock(). Used by the sigio thread, but the UML thread * synchronizes with it. */ -struct pollfds current_poll = { - .poll = NULL, - .size = 0, - .used = 0 -}; - -struct pollfds next_poll = { - .poll = NULL, - .size = 0, - .used = 0 -}; +static struct pollfds current_poll; +static struct pollfds next_poll; +static struct pollfds all_sigio_fds; static int write_sigio_thread(void *unused) { @@ -78,7 +70,8 @@ static int write_sigio_thread(void *unused) n = os_read_file(sigio_private[1], &c, sizeof(c)); if(n != sizeof(c)) printk("write_sigio_thread : " - "read failed, err = %d\n", -n); + "read on socket failed, " + "err = %d\n", -n); tmp = current_poll; current_poll = next_poll; next_poll = tmp; @@ -93,35 +86,36 @@ static int write_sigio_thread(void *unused) n = os_write_file(respond_fd, &c, sizeof(c)); if(n != sizeof(c)) - printk("write_sigio_thread : write failed, " - "err = %d\n", -n); + printk("write_sigio_thread : write on socket " + "failed, err = %d\n", -n); } } return 0; } -static int need_poll(int n) +static int need_poll(struct pollfds *polls, int n) { - if(n <= next_poll.size){ - next_poll.used = n; - return(0); + if(n <= polls->size){ + polls->used = n; + return 0; } - kfree(next_poll.poll); - next_poll.poll = um_kmalloc_atomic(n * sizeof(struct pollfd)); - if(next_poll.poll == NULL){ + kfree(polls->poll); + polls->poll = um_kmalloc_atomic(n * sizeof(struct pollfd)); + if(polls->poll == NULL){ printk("need_poll : failed to allocate new pollfds\n"); - next_poll.size = 0; - next_poll.used = 0; - return(-1); + polls->size = 0; + polls->used = 0; + return -ENOMEM; } - next_poll.size = n; - next_poll.used = n; - return(0); + polls->size = n; + polls->used = n; + return 0; } /* Must be called with sigio_lock held, because it's needed by the marked - * critical section. */ + * critical section. + */ static void update_thread(void) { unsigned long flags; @@ -156,34 +150,39 @@ static void update_thread(void) set_signals(flags); } -int add_sigio_fd(int fd, int read) +int add_sigio_fd(int fd) { - int err = 0, i, n, events; + struct pollfd *p; + int err = 0, i, n; sigio_lock(); + for(i = 0; i < all_sigio_fds.used; i++){ + if(all_sigio_fds.poll[i].fd == fd) + break; + } + if(i == all_sigio_fds.used) + goto out; + + p = &all_sigio_fds.poll[i]; + for(i = 0; i < current_poll.used; i++){ if(current_poll.poll[i].fd == fd) goto out; } n = current_poll.used + 1; - err = need_poll(n); + err = need_poll(&next_poll, n); if(err) goto out; for(i = 0; i < current_poll.used; i++) next_poll.poll[i] = current_poll.poll[i]; - if(read) events = POLLIN; - else events = POLLOUT; - - next_poll.poll[n - 1] = ((struct pollfd) { .fd = fd, - .events = events, - .revents = 0 }); + next_poll.poll[n - 1] = *p; update_thread(); out: sigio_unlock(); - return(err); + return err; } int ignore_sigio_fd(int fd) @@ -191,6 +190,13 @@ int ignore_sigio_fd(int fd) struct pollfd *p; int err = 0, i, n = 0; + /* This is called from exitcalls elsewhere in UML - if + * sigio_cleanup has already run, then update_thread will hang + * or fail because the thread is no longer running. + */ + if(write_sigio_pid == -1) + return -EIO; + sigio_lock(); for(i = 0; i < current_poll.used; i++){ if(current_poll.poll[i].fd == fd) break; @@ -198,24 +204,20 @@ int ignore_sigio_fd(int fd) if(i == current_poll.used) goto out; - err = need_poll(current_poll.used - 1); + err = need_poll(&next_poll, current_poll.used - 1); if(err) goto out; for(i = 0; i < current_poll.used; i++){ p = ¤t_poll.poll[i]; - if(p->fd != fd) next_poll.poll[n++] = current_poll.poll[i]; - } - if(n == i){ - printk("ignore_sigio_fd : fd %d not found\n", fd); - err = -1; - goto out; + if(p->fd != fd) + next_poll.poll[n++] = *p; } update_thread(); out: sigio_unlock(); - return(err); + return err; } static struct pollfd *setup_initial_poll(int fd) @@ -227,13 +229,13 @@ static struct pollfd *setup_initial_poll(int fd) printk("setup_initial_poll : failed to allocate poll\n"); return NULL; } - *p = ((struct pollfd) { .fd = fd, + *p = ((struct pollfd) { .fd = fd, .events = POLLIN, .revents = 0 }); return p; } -void write_sigio_workaround(void) +static void write_sigio_workaround(void) { unsigned long stack; struct pollfd *p; @@ -314,10 +316,38 @@ out_close1: close(l_write_sigio_fds[1]); } -void sigio_cleanup(void) +void maybe_sigio_broken(int fd, int read) +{ + int err; + + if(!isatty(fd)) + return; + + if((read || pty_output_sigio) && (!read || pty_close_sigio)) + return; + + write_sigio_workaround(); + + sigio_lock(); + err = need_poll(&all_sigio_fds, all_sigio_fds.used + 1); + if(err){ + printk("maybe_sigio_broken - failed to add pollfd\n"); + goto out; + } + all_sigio_fds.poll[all_sigio_fds.used++] = + ((struct pollfd) { .fd = fd, + .events = read ? POLLIN : POLLOUT, + .revents = 0 }); +out: + sigio_unlock(); +} + +static void sigio_cleanup(void) { if(write_sigio_pid != -1){ os_kill_process(write_sigio_pid, 1); write_sigio_pid = -1; } } + +__uml_exitcall(sigio_cleanup); |