[ PATCH 2/7 ] UML - Move SIGIO testing to sigio.c

Jeff Dike
2007-03-22T16:10:06Z

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>
--
arch/um/include/user_util.h | 3
arch/um/os-Linux/sigio.c | 145 ++++++++++++++++++++++++++++++++++++++++++++
arch/um/os-Linux/start_up.c | 145 --------------------------------------------
3 files changed, 145 insertions(+), 148 deletions(-)

Index: linux-2.6.21-mm/arch/um/os-Linux/start_up.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/os-Linux/start_up.c 2007-03-21 15:22:48.000000000 -0400
+++ linux-2.6.21-mm/arch/um/os-Linux/start_up.c 2007-03-21 15:24:33.000000000 -0400
@@ -553,148 +553,3 @@ int __init parse_iomem(char *str, int *a
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();
-}
-
Index: linux-2.6.21-mm/arch/um/os-Linux/sigio.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/os-Linux/sigio.c 2007-03-21 15:22:48.000000000 -0400
+++ linux-2.6.21-mm/arch/um/os-Linux/sigio.c 2007-03-21 16:16:50.000000000 -0400
@@ -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();
+}
Index: linux-2.6.21-mm/arch/um/include/user_util.h
===================================================================
--- linux-2.6.21-mm.orig/arch/um/include/user_util.h 2007-03-21 16:16:43.000000000 -0400
+++ linux-2.6.21-mm/arch/um/include/user_util.h 2007-03-21 16:17:50.000000000 -0400
@@ -51,9 +51,6 @@ extern unsigned long _stext, _etext, _sd
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);