X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=arch%2Fum%2Fos-Linux%2Fsigio.c;h=abf47a7c4abd795c039f4c98136163819adb92a4;hb=4adeaaf51ebcc3f629f5512b96aebb5089388bca;hp=3fc43b33db667d370ceabf7e63794b43ab0df441;hpb=cb2ebc59ff52cee770cfd6ba5f23a6cc3c214648;p=linux-2.6-omap-h63xx.git

diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 3fc43b33db6..abf47a7c4ab 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -1,32 +1,33 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
 #include <unistd.h>
-#include <stdlib.h>
-#include <termios.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
 #include <pty.h>
+#include <sched.h>
 #include <signal.h>
-#include <errno.h>
 #include <string.h>
-#include <sched.h>
-#include <sys/socket.h>
-#include <sys/poll.h>
-#include "init.h"
-#include "user.h"
+#include "kern_constants.h"
 #include "kern_util.h"
-#include "user_util.h"
-#include "sigio.h"
+#include "init.h"
 #include "os.h"
+#include "sigio.h"
 #include "um_malloc.h"
+#include "user.h"
 
-/* Protected by sigio_lock(), also used by sigio_cleanup, which is an
+/*
+ * Protected by sigio_lock(), also used by sigio_cleanup, which is an
  * exitcall.
  */
 static int write_sigio_pid = -1;
+static unsigned long write_sigio_stack;
 
-/* These arrays are initialized before the sigio thread is started, and
+/*
+ * These arrays are initialized before the sigio thread is started, and
  * the descriptors closed after it is killed.  So, it can't see them change.
  * On the UML side, they are changed under the sigio_lock.
  */
@@ -41,7 +42,8 @@ struct pollfds {
 	int used;
 };
 
-/* Protected by sigio_lock().  Used by the sigio thread, but the UML thread
+/*
+ * Protected by sigio_lock().  Used by the sigio thread, but the UML thread
  * synchronizes with it.
  */
 static struct pollfds current_poll;
@@ -55,24 +57,28 @@ static int write_sigio_thread(void *unused)
 	int i, n, respond_fd;
 	char c;
 
-        signal(SIGWINCH, SIG_IGN);
+	signal(SIGWINCH, SIG_IGN);
 	fds = &current_poll;
-	while(1){
+	while (1) {
 		n = poll(fds->poll, fds->used, -1);
-		if(n < 0){
-			if(errno == EINTR) continue;
-			printk("write_sigio_thread : poll returned %d, "
-			       "errno = %d\n", n, errno);
+		if (n < 0) {
+			if (errno == EINTR)
+				continue;
+			printk(UM_KERN_ERR "write_sigio_thread : poll returned "
+			       "%d, errno = %d\n", n, errno);
 		}
-		for(i = 0; i < fds->used; i++){
+		for (i = 0; i < fds->used; i++) {
 			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));
-				if(n != sizeof(c))
-					printk("write_sigio_thread : "
+			if (p->revents == 0)
+				continue;
+			if (p->fd == sigio_private[1]) {
+				CATCH_EINTR(n = read(sigio_private[1], &c,
+						     sizeof(c)));
+				if (n != sizeof(c))
+					printk(UM_KERN_ERR
+					       "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 +91,11 @@ static int write_sigio_thread(void *unused)
 					(fds->used - i) * sizeof(*fds->poll));
 			}
 
-			n = os_write_file(respond_fd, &c, sizeof(c));
-			if(n != sizeof(c))
-				printk("write_sigio_thread : write on socket "
-				       "failed, err = %d\n", -n);
+			CATCH_EINTR(n = write(respond_fd, &c, sizeof(c)));
+			if (n != sizeof(c))
+				printk(UM_KERN_ERR "write_sigio_thread : "
+				       "write on socket failed, err = %d\n",
+				       errno);
 		}
 	}
 
@@ -99,12 +106,13 @@ static int need_poll(struct pollfds *polls, int n)
 {
 	struct pollfd *new;
 
-	if(n <= polls->size)
+	if (n <= polls->size)
 		return 0;
 
-	new = um_kmalloc_atomic(n * sizeof(struct pollfd));
-	if(new == NULL){
-		printk("need_poll : failed to allocate new pollfds\n");
+	new = kmalloc(n * sizeof(struct pollfd), UM_GFP_ATOMIC);
+	if (new == NULL) {
+		printk(UM_KERN_ERR "need_poll : failed to allocate new "
+		       "pollfds\n");
 		return -ENOMEM;
 	}
 
@@ -116,7 +124,8 @@ static int need_poll(struct pollfds *polls, int n)
 	return 0;
 }
 
-/* Must be called with sigio_lock held, because it's needed by the marked
+/*
+ * Must be called with sigio_lock held, because it's needed by the marked
  * critical section.
  */
 static void update_thread(void)
@@ -126,15 +135,17 @@ static void update_thread(void)
 	char c;
 
 	flags = set_signals(0);
-	n = os_write_file(sigio_private[0], &c, sizeof(c));
-	if(n != sizeof(c)){
-		printk("update_thread : write failed, err = %d\n", -n);
+	CATCH_EINTR(n = write(sigio_private[0], &c, sizeof(c)));
+	if (n != sizeof(c)) {
+		printk(UM_KERN_ERR "update_thread : write failed, err = %d\n",
+		       errno);
 		goto fail;
 	}
 
-	n = os_read_file(sigio_private[0], &c, sizeof(c));
-	if(n != sizeof(c)){
-		printk("update_thread : read failed, err = %d\n", -n);
+	CATCH_EINTR(n = read(sigio_private[0], &c, sizeof(c)));
+	if (n != sizeof(c)) {
+		printk(UM_KERN_ERR "update_thread : read failed, err = %d\n",
+		       errno);
 		goto fail;
 	}
 
@@ -142,8 +153,10 @@ static void update_thread(void)
 	return;
  fail:
 	/* Critical section start */
-	if(write_sigio_pid != -1)
+	if (write_sigio_pid != -1) {
 		os_kill_process(write_sigio_pid, 1);
+		free_stack(write_sigio_stack, 0);
+	}
 	write_sigio_pid = -1;
 	close(sigio_private[0]);
 	close(sigio_private[1]);
@@ -159,23 +172,23 @@ int add_sigio_fd(int fd)
 	int err = 0, i, n;
 
 	sigio_lock();
-	for(i = 0; i < all_sigio_fds.used; i++){
-		if(all_sigio_fds.poll[i].fd == fd)
+	for (i = 0; i < all_sigio_fds.used; i++) {
+		if (all_sigio_fds.poll[i].fd == fd)
 			break;
 	}
-	if(i == all_sigio_fds.used)
+	if (i == all_sigio_fds.used)
 		goto out;
 
 	p = &all_sigio_fds.poll[i];
 
-	for(i = 0; i < current_poll.used; i++){
-		if(current_poll.poll[i].fd == fd)
+	for (i = 0; i < current_poll.used; i++) {
+		if (current_poll.poll[i].fd == fd)
 			goto out;
 	}
 
 	n = current_poll.used;
 	err = need_poll(&next_poll, n + 1);
-	if(err)
+	if (err)
 		goto out;
 
 	memcpy(next_poll.poll, current_poll.poll,
@@ -193,27 +206,29 @@ int ignore_sigio_fd(int fd)
 	struct pollfd *p;
 	int err = 0, i, n = 0;
 
-	/* This is called from exitcalls elsewhere in UML - if
+	/*
+	 * This is called from exitcalls elsewhere in UML - if
 	 * sigio_cleanup has already run, then update_thread will hang
 	 * or fail because the thread is no longer running.
 	 */
-	if(write_sigio_pid == -1)
+	if (write_sigio_pid == -1)
 		return -EIO;
 
 	sigio_lock();
-	for(i = 0; i < current_poll.used; i++){
-		if(current_poll.poll[i].fd == fd) break;
+	for (i = 0; i < current_poll.used; i++) {
+		if (current_poll.poll[i].fd == fd)
+			break;
 	}
-	if(i == current_poll.used)
+	if (i == current_poll.used)
 		goto out;
 
 	err = need_poll(&next_poll, current_poll.used - 1);
-	if(err)
+	if (err)
 		goto out;
 
-	for(i = 0; i < current_poll.used; i++){
+	for (i = 0; i < current_poll.used; i++) {
 		p = &current_poll.poll[i];
-		if(p->fd != fd)
+		if (p->fd != fd)
 			next_poll.poll[n++] = *p;
 	}
 	next_poll.used = current_poll.used - 1;
@@ -228,9 +243,10 @@ static struct pollfd *setup_initial_poll(int fd)
 {
 	struct pollfd *p;
 
-	p = um_kmalloc(sizeof(struct pollfd));
+	p = kmalloc(sizeof(struct pollfd), UM_GFP_KERNEL);
 	if (p == NULL) {
-		printk("setup_initial_poll : failed to allocate poll\n");
+		printk(UM_KERN_ERR "setup_initial_poll : failed to allocate "
+		       "poll\n");
 		return NULL;
 	}
 	*p = ((struct pollfd) { .fd		= fd,
@@ -241,7 +257,6 @@ static struct pollfd *setup_initial_poll(int fd)
 
 static void write_sigio_workaround(void)
 {
-	unsigned long stack;
 	struct pollfd *p;
 	int err;
 	int l_write_sigio_fds[2];
@@ -257,27 +272,29 @@ static void write_sigio_workaround(void)
 		return;
 
 	err = os_pipe(l_write_sigio_fds, 1, 1);
-	if(err < 0){
-		printk("write_sigio_workaround - os_pipe 1 failed, "
+	if (err < 0) {
+		printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 1 failed, "
 		       "err = %d\n", -err);
 		return;
 	}
 	err = os_pipe(l_sigio_private, 1, 1);
-	if(err < 0){
-		printk("write_sigio_workaround - os_pipe 2 failed, "
+	if (err < 0) {
+		printk(UM_KERN_ERR "write_sigio_workaround - os_pipe 2 failed, "
 		       "err = %d\n", -err);
 		goto out_close1;
 	}
 
 	p = setup_initial_poll(l_sigio_private[1]);
-	if(!p)
+	if (!p)
 		goto out_close2;
 
 	sigio_lock();
 
-	/* Did we race? Don't try to optimize this, please, it's not so likely
-	 * to happen, and no more than once at the boot. */
-	if(write_sigio_pid != -1)
+	/*
+	 * Did we race? Don't try to optimize this, please, it's not so likely
+	 * to happen, and no more than once at the boot.
+	 */
+	if (write_sigio_pid != -1)
 		goto out_free;
 
 	current_poll = ((struct pollfds) { .poll 	= p,
@@ -291,7 +308,8 @@ static void write_sigio_workaround(void)
 	memcpy(sigio_private, l_sigio_private, sizeof(l_sigio_private));
 
 	write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
-					    CLONE_FILES | CLONE_VM, &stack, 0);
+					    CLONE_FILES | CLONE_VM,
+					    &write_sigio_stack);
 
 	if (write_sigio_pid < 0)
 		goto out_clear;
@@ -320,23 +338,27 @@ 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;
 
-	if(!isatty(fd))
+	if (!isatty(fd))
 		return;
 
-	if((read || pty_output_sigio) && (!read || pty_close_sigio))
+	if ((read || pty_output_sigio) && (!read || pty_close_sigio))
 		return;
 
 	write_sigio_workaround();
 
 	sigio_lock();
 	err = need_poll(&all_sigio_fds, all_sigio_fds.used + 1);
-	if(err){
-		printk("maybe_sigio_broken - failed to add pollfd for "
-		       "descriptor %d\n", fd);
+	if (err) {
+		printk(UM_KERN_ERR "maybe_sigio_broken - failed to add pollfd "
+		       "for descriptor %d\n", fd);
 		goto out;
 	}
 
@@ -350,10 +372,171 @@ out:
 
 static void sigio_cleanup(void)
 {
-	if(write_sigio_pid != -1){
-		os_kill_process(write_sigio_pid, 1);
-		write_sigio_pid = -1;
-	}
+	if (write_sigio_pid == -1)
+		return;
+
+	os_kill_process(write_sigio_pid, 1);
+	free_stack(write_sigio_stack, 0);
+	write_sigio_pid = -1;
 }
 
 __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(UM_KERN_ERR "check_one_sigio failed, errno = %d\n",
+		       -pty.err);
+		return;
+	}
+
+	master = pty.master;
+	slave = pty.slave;
+
+	if ((master == -1) || (slave == -1)) {
+		printk(UM_KERN_ERR "check_one_sigio failed to allocate a "
+		       "pty\n");
+		return;
+	}
+
+	/* Not now, but complain so we now where we failed. */
+	err = raw(master);
+	if (err < 0) {
+		printk(UM_KERN_ERR "check_one_sigio : raw failed, errno = %d\n",
+		      -err);
+		return;
+	}
+
+	err = async_pty(master, slave);
+	if (err < 0) {
+		printk(UM_KERN_ERR "check_one_sigio : sigio_async failed, "
+		       "err = %d\n", -err);
+		return;
+	}
+
+	if (sigaction(SIGIO, NULL, &old) < 0) {
+		printk(UM_KERN_ERR "check_one_sigio : sigaction 1 failed, "
+		       "errno = %d\n", errno);
+		return;
+	}
+
+	new = old;
+	new.sa_handler = handler;
+	if (sigaction(SIGIO, &new, NULL) < 0) {
+		printk(UM_KERN_ERR "check_one_sigio : sigaction 2 failed, "
+		       "errno = %d\n", errno);
+		return;
+	}
+
+	got_sigio = 0;
+	(*proc)(master, slave);
+
+	close(master);
+	close(slave);
+
+	if (sigaction(SIGIO, &old, NULL) < 0)
+		printk(UM_KERN_ERR "check_one_sigio : sigaction 3 failed, "
+		       "errno = %d\n", errno);
+}
+
+static void tty_output(int master, int slave)
+{
+	int n;
+	char buf[512];
+
+	printk(UM_KERN_INFO "Checking that host ptys support output SIGIO...");
+
+	memset(buf, 0, sizeof(buf));
+
+	while (write(master, buf, sizeof(buf)) > 0) ;
+	if (errno != EAGAIN)
+		printk(UM_KERN_ERR "tty_output : write failed, errno = %d\n",
+		       errno);
+	while (((n = read(slave, buf, sizeof(buf))) > 0) && !got_sigio)
+		;
+
+	if (got_sigio) {
+		printk(UM_KERN_CONT "Yes\n");
+		pty_output_sigio = 1;
+	} else if (n == -EAGAIN)
+		printk(UM_KERN_CONT "No, enabling workaround\n");
+	else
+		printk(UM_KERN_CONT "tty_output : read failed, err = %d\n", n);
+}
+
+static void tty_close(int master, int slave)
+{
+	printk(UM_KERN_INFO "Checking that host ptys support SIGIO on "
+	       "close...");
+
+	close(slave);
+	if (got_sigio) {
+		printk(UM_KERN_CONT "Yes\n");
+		pty_close_sigio = 1;
+	} else
+		printk(UM_KERN_CONT "No, enabling workaround\n");
+}
+
+void __init check_sigio(void)
+{
+	if ((access("/dev/ptmx", R_OK) < 0) &&
+	    (access("/dev/ptyp0", R_OK) < 0)) {
+		printk(UM_KERN_WARNING "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();
+}