uml: move SIGIO testing to sigio.c

This patch narrows the sigio interface.  The boot-time SIGIO testing used to
be in start_up.c, which meant that pty_output_sigio and pty_close_sigio needed
to be global.  By moving that code here, those can become static and the
declarations moved from user_util.h.

os_check_bugs is also here because it only does the SIGIO checking.  If it
does more, it'll probably move back to start_up.c.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 145 insertions, 148 deletions

diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h
index b52bc4084830..df4869aa9406 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -51,9 +51,6 @@ extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end;
 extern unsigned long _unprotected_end;
 extern unsigned long brk_start;
 
-extern int pty_output_sigio;
-extern int pty_close_sigio;
-
 extern void *add_signal_handler(int sig, void (*handler)(int));
 extern int linux_main(int argc, char **argv);
 extern void set_cmdline(char *cmd);
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 3fc43b33db66..c61d01bf46e4 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>
@@ -20,6 +21,7 @@
 #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.
@@ -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 +363,142 @@ 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(os_write_file(master, buf, sizeof(buf)) > 0) ;
+        if(errno != EAGAIN)
+                panic("check_sigio : write failed, errno = %d\n", errno);
+        while(((n = os_read_file(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("check_sigio : 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();
+}
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 1244179e6c83..1540f21d6997 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -553,148 +553,3 @@ int __init parse_iomem(char *str, int *add)
  out:
         return 1;
 }
-
-
-/* Changed during early boot */
-int pty_output_sigio = 0;
-int pty_close_sigio = 0;
-
-/* 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(os_write_file(master, buf, sizeof(buf)) > 0) ;
-        if(errno != EAGAIN)
-                panic("check_sigio : write failed, errno = %d\n", errno);
-        while(((n = os_read_file(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("check_sigio : 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);
-}
-
-void os_check_bugs(void)
-{
-        check_ptrace();
-        check_sigio();
-}
-