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authorJeff Dike <jdike@addtoit.com>2007-05-06 14:51:06 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-07 12:13:01 -0700
commitc65badbdf5dc117e45873e760f807063ad59a854 (patch)
treea83dd52066e3efef9b70c35bec8fccdf9db3d457 /arch/um/os-Linux/sigio.c
parentc5e631cf65f4d6875efcd571275436f2964a8b48 (diff)
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>
Diffstat (limited to 'arch/um/os-Linux/sigio.c')
-rw-r--r--arch/um/os-Linux/sigio.c145
1 files changed, 145 insertions, 0 deletions
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();
+}