diff options
Diffstat (limited to 'arch/um/os-Linux/sigio.c')
| -rw-r--r-- | arch/um/os-Linux/sigio.c | 164 |
1 files changed, 155 insertions, 9 deletions
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c index 3fc43b33db66..8d4e0c6b8c92 100644 --- a/arch/um/os-Linux/sigio.c +++ b/arch/um/os-Linux/sigio.c @@ -8,6 +8,7 @@ #include <termios.h> #include <pty.h> #include <signal.h> +#include <fcntl.h> #include <errno.h> #include <string.h> #include <sched.h> @@ -16,10 +17,10 @@ #include "init.h" #include "user.h" #include "kern_util.h" -#include "user_util.h" #include "sigio.h" #include "os.h" #include "um_malloc.h" +#include "init.h" /* Protected by sigio_lock(), also used by sigio_cleanup, which is an * exitcall. @@ -68,11 +69,12 @@ static int write_sigio_thread(void *unused) p = &fds->poll[i]; if(p->revents == 0) continue; if(p->fd == sigio_private[1]){ - n = os_read_file(sigio_private[1], &c, sizeof(c)); + CATCH_EINTR(n = read(sigio_private[1], &c, + sizeof(c))); if(n != sizeof(c)) printk("write_sigio_thread : " "read on socket failed, " - "err = %d\n", -n); + "err = %d\n", errno); tmp = current_poll; current_poll = next_poll; next_poll = tmp; @@ -85,10 +87,10 @@ static int write_sigio_thread(void *unused) (fds->used - i) * sizeof(*fds->poll)); } - n = os_write_file(respond_fd, &c, sizeof(c)); + CATCH_EINTR(n = write(respond_fd, &c, sizeof(c))); if(n != sizeof(c)) printk("write_sigio_thread : write on socket " - "failed, err = %d\n", -n); + "failed, err = %d\n", errno); } } @@ -126,15 +128,15 @@ static void update_thread(void) char c; flags = set_signals(0); - n = os_write_file(sigio_private[0], &c, sizeof(c)); + n = write(sigio_private[0], &c, sizeof(c)); if(n != sizeof(c)){ - printk("update_thread : write failed, err = %d\n", -n); + printk("update_thread : write failed, err = %d\n", errno); goto fail; } - n = os_read_file(sigio_private[0], &c, sizeof(c)); + CATCH_EINTR(n = read(sigio_private[0], &c, sizeof(c))); if(n != sizeof(c)){ - printk("update_thread : read failed, err = %d\n", -n); + printk("update_thread : read failed, err = %d\n", errno); goto fail; } @@ -320,6 +322,10 @@ out_close1: close(l_write_sigio_fds[1]); } +/* Changed during early boot */ +static int pty_output_sigio = 0; +static int pty_close_sigio = 0; + void maybe_sigio_broken(int fd, int read) { int err; @@ -357,3 +363,143 @@ static void sigio_cleanup(void) } __uml_exitcall(sigio_cleanup); + +/* Used as a flag during SIGIO testing early in boot */ +static volatile int got_sigio = 0; + +static void __init handler(int sig) +{ + got_sigio = 1; +} + +struct openpty_arg { + int master; + int slave; + int err; +}; + +static void openpty_cb(void *arg) +{ + struct openpty_arg *info = arg; + + info->err = 0; + if(openpty(&info->master, &info->slave, NULL, NULL, NULL)) + info->err = -errno; +} + +static int async_pty(int master, int slave) +{ + int flags; + + flags = fcntl(master, F_GETFL); + if(flags < 0) + return -errno; + + if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) || + (fcntl(master, F_SETOWN, os_getpid()) < 0)) + return -errno; + + if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0)) + return -errno; + + return(0); +} + +static void __init check_one_sigio(void (*proc)(int, int)) +{ + struct sigaction old, new; + struct openpty_arg pty = { .master = -1, .slave = -1 }; + int master, slave, err; + + initial_thread_cb(openpty_cb, &pty); + if(pty.err){ + printk("openpty failed, errno = %d\n", -pty.err); + return; + } + + master = pty.master; + slave = pty.slave; + + if((master == -1) || (slave == -1)){ + printk("openpty failed to allocate a pty\n"); + return; + } + + /* Not now, but complain so we now where we failed. */ + err = raw(master); + if (err < 0) + panic("check_sigio : __raw failed, errno = %d\n", -err); + + err = async_pty(master, slave); + if(err < 0) + panic("tty_fds : sigio_async failed, err = %d\n", -err); + + if(sigaction(SIGIO, NULL, &old) < 0) + panic("check_sigio : sigaction 1 failed, errno = %d\n", errno); + new = old; + new.sa_handler = handler; + if(sigaction(SIGIO, &new, NULL) < 0) + panic("check_sigio : sigaction 2 failed, errno = %d\n", errno); + + got_sigio = 0; + (*proc)(master, slave); + + close(master); + close(slave); + + if(sigaction(SIGIO, &old, NULL) < 0) + panic("check_sigio : sigaction 3 failed, errno = %d\n", errno); +} + +static void tty_output(int master, int slave) +{ + int n; + char buf[512]; + + printk("Checking that host ptys support output SIGIO..."); + + memset(buf, 0, sizeof(buf)); + + while(write(master, buf, sizeof(buf)) > 0) ; + if(errno != EAGAIN) + panic("tty_output : write failed, errno = %d\n", errno); + while(((n = read(slave, buf, sizeof(buf))) > 0) && !got_sigio) ; + + if(got_sigio){ + printk("Yes\n"); + pty_output_sigio = 1; + } + else if(n == -EAGAIN) + printk("No, enabling workaround\n"); + else panic("tty_output : read failed, err = %d\n", n); +} + +static void tty_close(int master, int slave) +{ + printk("Checking that host ptys support SIGIO on close..."); + + close(slave); + if(got_sigio){ + printk("Yes\n"); + pty_close_sigio = 1; + } + else printk("No, enabling workaround\n"); +} + +void __init check_sigio(void) +{ + if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) && + (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){ + printk("No pseudo-terminals available - skipping pty SIGIO " + "check\n"); + return; + } + check_one_sigio(tty_output); + check_one_sigio(tty_close); +} + +/* Here because it only does the SIGIO testing for now */ +void __init os_check_bugs(void) +{ + check_sigio(); +} |