diff options
| -rw-r--r-- | arch/um/drivers/chan_user.c | 70 | ||||
| -rw-r--r-- | arch/um/drivers/line.c | 60 | ||||
| -rw-r--r-- | arch/um/include/chan_user.h | 3 | ||||
| -rw-r--r-- | arch/um/os-Linux/skas/process.c | 2 |
4 files changed, 80 insertions, 55 deletions
diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c index 5d1289d..8b81bd5 100644 --- a/arch/um/drivers/chan_user.c +++ b/arch/um/drivers/chan_user.c @@ -51,19 +51,21 @@ error: /* * UML SIGWINCH handling * - * The point of this is to handle SIGWINCH on consoles which have host ttys and - * relay them inside UML to whatever might be running on the console and cares - * about the window size (since SIGWINCH notifies about terminal size changes). + * The point of this is to handle SIGWINCH on consoles which have host + * ttys and relay them inside UML to whatever might be running on the + * console and cares about the window size (since SIGWINCH notifies + * about terminal size changes). * - * So, we have a separate thread for each host tty attached to a UML device - * (side-issue - I'm annoyed that one thread can't have multiple controlling - * ttys for purposed of handling SIGWINCH, but I imagine there are other reasons - * that doesn't make any sense). + * So, we have a separate thread for each host tty attached to a UML + * device (side-issue - I'm annoyed that one thread can't have + * multiple controlling ttys for the purpose of handling SIGWINCH, but + * I imagine there are other reasons that doesn't make any sense). * - * SIGWINCH can't be received synchronously, so you have to set up to receive it - * as a signal. That being the case, if you are going to wait for it, it is - * convenient to sit in sigsuspend() and wait for the signal to bounce you out of - * it (see below for how we make sure to exit only on SIGWINCH). + * SIGWINCH can't be received synchronously, so you have to set up to + * receive it as a signal. That being the case, if you are going to + * wait for it, it is convenient to sit in sigsuspend() and wait for + * the signal to bounce you out of it (see below for how we make sure + * to exit only on SIGWINCH). */ static void winch_handler(int sig) @@ -112,7 +114,8 @@ static int winch_thread(void *arg) err = os_new_tty_pgrp(pty_fd, os_getpid()); if(err < 0){ - printk("winch_thread : new_tty_pgrp failed, err = %d\n", -err); + printk("winch_thread : new_tty_pgrp failed on fd %d, " + "err = %d\n", pty_fd, -err); exit(1); } @@ -126,8 +129,9 @@ static int winch_thread(void *arg) "err = %d\n", -count); while(1){ - /* This will be interrupted by SIGWINCH only, since other signals - * are blocked.*/ + /* This will be interrupted by SIGWINCH only, since + * other signals are blocked. + */ sigsuspend(&sigs); count = os_write_file(pipe_fd, &c, sizeof(c)); @@ -137,10 +141,10 @@ static int winch_thread(void *arg) } } -static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out) +static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out, + unsigned long *stack_out) { struct winch_data data; - unsigned long stack; int fds[2], n, err; char c; @@ -153,9 +157,11 @@ static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out) data = ((struct winch_data) { .pty_fd = fd, .pipe_fd = fds[1] } ); /* CLONE_FILES so this thread doesn't hold open files which are open - * now, but later closed. This is a problem with /dev/net/tun. + * now, but later closed in a different thread. This is a + * problem with /dev/net/tun, which if held open by this + * thread, prevents the TUN/TAP device from being reused. */ - err = run_helper_thread(winch_thread, &data, CLONE_FILES, &stack, 0); + err = run_helper_thread(winch_thread, &data, CLONE_FILES, stack_out, 0); if(err < 0){ printk("fork of winch_thread failed - errno = %d\n", -err); goto out_close; @@ -187,25 +193,25 @@ static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out) void register_winch(int fd, struct tty_struct *tty) { - int pid, thread, thread_fd = -1; - int count; + unsigned long stack; + int pid, thread, count, thread_fd = -1; char c = 1; if(!isatty(fd)) return; pid = tcgetpgrp(fd); - if(!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd, - tty) && (pid == -1)){ - thread = winch_tramp(fd, tty, &thread_fd); - if(thread > 0){ - register_winch_irq(thread_fd, fd, thread, tty); - - count = os_write_file(thread_fd, &c, sizeof(c)); - if(count != sizeof(c)) - printk("register_winch : failed to write " - "synchronization byte, err = %d\n", - -count); - } + if (!CHOOSE_MODE_PROC(is_tracer_winch, is_skas_winch, pid, fd, tty) && + (pid == -1)) { + thread = winch_tramp(fd, tty, &thread_fd, &stack); + if (thread < 0) + return; + + register_winch_irq(thread_fd, fd, thread, tty, stack); + + count = os_write_file(thread_fd, &c, sizeof(c)); + if(count != sizeof(c)) + printk("register_winch : failed to write " + "synchronization byte, err = %d\n", -count); } } diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c index 1fb3e51..3e0b68e 100644 --- a/arch/um/drivers/line.c +++ b/arch/um/drivers/line.c @@ -749,8 +749,24 @@ struct winch { int tty_fd; int pid; struct tty_struct *tty; + unsigned long stack; }; +static void free_winch(struct winch *winch, int free_irq_ok) +{ + list_del(&winch->list); + + if (winch->pid != -1) + os_kill_process(winch->pid, 1); + if (winch->fd != -1) + os_close_file(winch->fd); + if (winch->stack != 0) + free_stack(winch->stack, 0); + if (free_irq_ok) + free_irq(WINCH_IRQ, winch); + kfree(winch); +} + static irqreturn_t winch_interrupt(int irq, void *data) { struct winch *winch = data; @@ -767,12 +783,13 @@ static irqreturn_t winch_interrupt(int irq, void *data) "errno = %d\n", -err); printk("fd %d is losing SIGWINCH support\n", winch->tty_fd); + free_winch(winch, 0); return IRQ_HANDLED; } goto out; } } - tty = winch->tty; + tty = winch->tty; if (tty != NULL) { line = tty->driver_data; chan_window_size(&line->chan_list, &tty->winsize.ws_row, @@ -785,43 +802,44 @@ static irqreturn_t winch_interrupt(int irq, void *data) return IRQ_HANDLED; } -void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty) +void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty, + unsigned long stack) { struct winch *winch; winch = kmalloc(sizeof(*winch), GFP_KERNEL); if (winch == NULL) { printk("register_winch_irq - kmalloc failed\n"); - return; + goto cleanup; } *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list), .fd = fd, .tty_fd = tty_fd, .pid = pid, - .tty = tty }); + .tty = tty, + .stack = stack }); + + if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt, + IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM, + "winch", winch) < 0) { + printk("register_winch_irq - failed to register IRQ\n"); + goto out_free; + } spin_lock(&winch_handler_lock); list_add(&winch->list, &winch_handlers); spin_unlock(&winch_handler_lock); - if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt, - IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM, - "winch", winch) < 0) - printk("register_winch_irq - failed to register IRQ\n"); -} - -static void free_winch(struct winch *winch) -{ - list_del(&winch->list); - - if(winch->pid != -1) - os_kill_process(winch->pid, 1); - if(winch->fd != -1) - os_close_file(winch->fd); + return; - free_irq(WINCH_IRQ, winch); + out_free: kfree(winch); + cleanup: + os_kill_process(pid, 1); + os_close_file(fd); + if (stack != 0) + free_stack(stack, 0); } static void unregister_winch(struct tty_struct *tty) @@ -834,7 +852,7 @@ static void unregister_winch(struct tty_struct *tty) list_for_each(ele, &winch_handlers){ winch = list_entry(ele, struct winch, list); if(winch->tty == tty){ - free_winch(winch); + free_winch(winch, 1); break; } } @@ -850,7 +868,7 @@ static void winch_cleanup(void) list_for_each_safe(ele, next, &winch_handlers){ winch = list_entry(ele, struct winch, list); - free_winch(winch); + free_winch(winch, 1); } spin_unlock(&winch_handler_lock); diff --git a/arch/um/include/chan_user.h b/arch/um/include/chan_user.h index 714b713..5a2263e 100644 --- a/arch/um/include/chan_user.h +++ b/arch/um/include/chan_user.h @@ -42,7 +42,8 @@ extern void generic_free(void *data); struct tty_struct; extern void register_winch(int fd, struct tty_struct *tty); -extern void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty); +extern void register_winch_irq(int fd, int tty_fd, int pid, + struct tty_struct *tty, unsigned long stack); #define __channel_help(fn, prefix) \ __uml_help(fn, prefix "[0-9]*=<channel description>\n" \ diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 46c00cc..ba9af8d 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -41,7 +41,7 @@ int is_skas_winch(int pid, int fd, void *data) if(pid != os_getpgrp()) return(0); - register_winch_irq(-1, fd, -1, data); + register_winch_irq(-1, fd, -1, data, 0); return(1); } |
