X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fum%2Fdrivers%2Fchan_user.c;h=0cad3546cb8922a013893d516111f9f669115fdb;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=714bace49972d5108f80e9fcfc9fc7f50620b64e;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c index 714bace49..0cad3546c 100644 --- a/arch/um/drivers/chan_user.c +++ b/arch/um/drivers/chan_user.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com) + * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com) * Licensed under the GPL */ @@ -7,9 +7,9 @@ #include #include #include -#include #include #include +#include #include #include #include @@ -17,73 +17,55 @@ #include "user_util.h" #include "chan_user.h" #include "user.h" -#include "helper.h" #include "os.h" #include "choose-mode.h" #include "mode.h" -void generic_close(int fd, void *unused) -{ - close(fd); -} - -int generic_read(int fd, char *c_out, void *unused) -{ - int n; - - n = read(fd, c_out, sizeof(*c_out)); - if(n < 0){ - if(errno == EAGAIN) return(0); - return(-errno); - } - else if(n == 0) return(-EIO); - return(1); -} - -int generic_write(int fd, const char *buf, int n, void *unused) -{ - int count; - - count = write(fd, buf, n); - if(count < 0) return(-errno); - return(count); -} - -int generic_console_write(int fd, const char *buf, int n, void *unused) +int generic_console_write(int fd, const char *buf, int n) { struct termios save, new; int err; if(isatty(fd)){ - tcgetattr(fd, &save); + CATCH_EINTR(err = tcgetattr(fd, &save)); + if (err) + goto error; new = save; + /* The terminal becomes a bit less raw, to handle \n also as + * "Carriage Return", not only as "New Line". Otherwise, the new + * line won't start at the first column.*/ new.c_oflag |= OPOST; - tcsetattr(fd, TCSAFLUSH, &new); + CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &new)); + if (err) + goto error; } err = generic_write(fd, buf, n, NULL); - if(isatty(fd)) tcsetattr(fd, TCSAFLUSH, &save); + /* Restore raw mode, in any case; we *must* ignore any error apart + * EINTR, except for debug.*/ + if(isatty(fd)) + CATCH_EINTR(tcsetattr(fd, TCSAFLUSH, &save)); return(err); +error: + return(-errno); } -int generic_window_size(int fd, void *unused, unsigned short *rows_out, - unsigned short *cols_out) -{ - struct winsize size; - int ret = 0; - - if(ioctl(fd, TIOCGWINSZ, &size) == 0){ - ret = ((*rows_out != size.ws_row) || - (*cols_out != size.ws_col)); - *rows_out = size.ws_row; - *cols_out = size.ws_col; - } - return(ret); -} - -void generic_free(void *data) -{ - kfree(data); -} +/* + * 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). + * + * 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). + * + * 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) { @@ -92,7 +74,6 @@ static void winch_handler(int sig) struct winch_data { int pty_fd; int pipe_fd; - int close_me; }; static int winch_thread(void *arg) @@ -100,103 +81,126 @@ static int winch_thread(void *arg) struct winch_data *data = arg; sigset_t sigs; int pty_fd, pipe_fd; + int count, err; char c = 1; - close(data->close_me); pty_fd = data->pty_fd; pipe_fd = data->pipe_fd; - if(write(pipe_fd, &c, sizeof(c)) != sizeof(c)) + count = os_write_file(pipe_fd, &c, sizeof(c)); + if(count != sizeof(c)) printk("winch_thread : failed to write synchronization " - "byte, errno = %d\n", errno); + "byte, err = %d\n", -count); + + /* We are not using SIG_IGN on purpose, so don't fix it as I thought to + * do! If using SIG_IGN, the sigsuspend() call below would not stop on + * SIGWINCH. */ signal(SIGWINCH, winch_handler); sigfillset(&sigs); - sigdelset(&sigs, SIGWINCH); + /* Block all signals possible. */ if(sigprocmask(SIG_SETMASK, &sigs, NULL) < 0){ printk("winch_thread : sigprocmask failed, errno = %d\n", errno); exit(1); } + /* In sigsuspend(), block anything else than SIGWINCH. */ + sigdelset(&sigs, SIGWINCH); if(setsid() < 0){ printk("winch_thread : setsid failed, errno = %d\n", errno); exit(1); } - if(ioctl(pty_fd, TIOCSCTTY, 0) < 0){ - printk("winch_thread : TIOCSCTTY failed, errno = %d\n", errno); - exit(1); - } - if(tcsetpgrp(pty_fd, os_getpid()) < 0){ - printk("winch_thread : tcsetpgrp failed, errno = %d\n", errno); + err = os_new_tty_pgrp(pty_fd, os_getpid()); + if(err < 0){ + printk("winch_thread : new_tty_pgrp failed, err = %d\n", -err); exit(1); } - if(read(pipe_fd, &c, sizeof(c)) != sizeof(c)) + /* These are synchronization calls between various UML threads on the + * host - since they are not different kernel threads, we cannot use + * kernel semaphores. We don't use SysV semaphores because they are + * persistent. */ + count = os_read_file(pipe_fd, &c, sizeof(c)); + if(count != sizeof(c)) printk("winch_thread : failed to read synchronization byte, " - "errno = %d\n", errno); + "err = %d\n", -count); while(1){ - pause(); - - if(write(pipe_fd, &c, sizeof(c)) != sizeof(c)){ - printk("winch_thread : write failed, errno = %d\n", - errno); - } + /* This will be interrupted by SIGWINCH only, since other signals + * are blocked.*/ + sigsuspend(&sigs); + + count = os_write_file(pipe_fd, &c, sizeof(c)); + if(count != sizeof(c)) + printk("winch_thread : write failed, err = %d\n", + -count); } } -static int winch_tramp(int fd, void *device_data, int *fd_out) +static int winch_tramp(int fd, struct tty_struct *tty, int *fd_out) { struct winch_data data; unsigned long stack; - int fds[2], pid, n, err; + int fds[2], n, err; char c; err = os_pipe(fds, 1, 1); - if(err){ - printk("winch_tramp : os_pipe failed, errno = %d\n", -err); - return(err); + if(err < 0){ + printk("winch_tramp : os_pipe failed, err = %d\n", -err); + goto out; } data = ((struct winch_data) { .pty_fd = fd, - .pipe_fd = fds[1], - .close_me = fds[0] } ); - pid = run_helper_thread(winch_thread, &data, 0, &stack, 0); - if(pid < 0){ + .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. + */ + err = run_helper_thread(winch_thread, &data, CLONE_FILES, &stack, 0); + if(err < 0){ printk("fork of winch_thread failed - errno = %d\n", errno); - return(pid); + goto out_close; } - close(fds[1]); *fd_out = fds[0]; - n = read(fds[0], &c, sizeof(c)); + n = os_read_file(fds[0], &c, sizeof(c)); if(n != sizeof(c)){ printk("winch_tramp : failed to read synchronization byte\n"); - printk("read returned %d, errno = %d\n", n, errno); + printk("read failed, err = %d\n", -n); printk("fd %d will not support SIGWINCH\n", fd); - *fd_out = -1; + err = -EINVAL; + goto out_close; } - return(pid); + return err ; + + out_close: + os_close_file(fds[1]); + os_close_file(fds[0]); + out: + return err; } -void register_winch(int fd, void *device_data) +void register_winch(int fd, struct tty_struct *tty) { - int pid, thread, thread_fd; + int pid, thread, thread_fd = -1; + int count; char c = 1; - if(!isatty(fd)) return; + if(!isatty(fd)) + return; pid = tcgetpgrp(fd); - if(!CHOOSE_MODE(is_tracer_winch(pid, fd, device_data), 0) && - (pid == -1)){ - thread = winch_tramp(fd, device_data, &thread_fd); - if(fd != -1){ - register_winch_irq(thread_fd, fd, thread, device_data); - - if(write(thread_fd, &c, sizeof(c)) != sizeof(c)) + 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\n"); + "synchronization byte, err = %d\n", + -count); } } }