7 files changed, 872 insertions, 15 deletions

diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile
index 08a4e628b24c..1659386b42bb 100644
--- a/arch/um/os-Linux/Makefile
+++ b/arch/um/os-Linux/Makefile
@@ -3,14 +3,17 @@
 # Licensed under the GPL
 #
 
-obj-y = aio.o elf_aux.o file.o helper.o main.o mem.o process.o signal.o \
-	start_up.o time.o trap.o tt.o tty.o uaccess.o umid.o user_syms.o \
-	util.o drivers/ sys-$(SUBARCH)/
+obj-y = aio.o elf_aux.o file.o helper.o irq.o main.o mem.o process.o sigio.o \
+	signal.o start_up.o time.o trap.o tt.o tty.o uaccess.o umid.o \
+	user_syms.o util.o drivers/ sys-$(SUBARCH)/
 
 obj-$(CONFIG_MODE_SKAS) += skas/
+obj-$(CONFIG_TTY_LOG) += tty_log.o
+user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
-USER_OBJS := aio.o elf_aux.o file.o helper.o main.o mem.o process.o signal.o \
-	start_up.o time.o trap.o tt.o tty.o uaccess.o umid.o util.o
+USER_OBJS := $(user-objs-y) aio.o elf_aux.o file.o helper.o irq.o main.o mem.o \
+	process.o sigio.o signal.o start_up.o time.o trap.o tt.o tty.o \
+	uaccess.o umid.o util.o
 
 elf_aux.o: $(ARCH_DIR)/kernel-offsets.h
 CFLAGS_elf_aux.o += -I$(objtree)/arch/um
diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c
new file mode 100644
index 000000000000..e599be423da1
--- /dev/null
+++ b/arch/um/os-Linux/irq.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/poll.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include "user_util.h"
+#include "kern_util.h"
+#include "user.h"
+#include "process.h"
+#include "sigio.h"
+#include "irq_user.h"
+#include "os.h"
+
+static struct pollfd *pollfds = NULL;
+static int pollfds_num = 0;
+static int pollfds_size = 0;
+
+int os_waiting_for_events(struct irq_fd *active_fds)
+{
+	struct irq_fd *irq_fd;
+	int i, n, err;
+
+	n = poll(pollfds, pollfds_num, 0);
+	if(n < 0){
+		err = -errno;
+		if(errno != EINTR)
+			printk("sigio_handler: os_waiting_for_events:"
+			       " poll returned %d, errno = %d\n", n, errno);
+		return err;
+	}
+
+	if(n == 0)
+		return 0;
+
+	irq_fd = active_fds;
+
+	for(i = 0; i < pollfds_num; i++){
+		if(pollfds[i].revents != 0){
+			irq_fd->current_events = pollfds[i].revents;
+			pollfds[i].fd = -1;
+		}
+		irq_fd = irq_fd->next;
+	}
+	return n;
+}
+
+int os_isatty(int fd)
+{
+	return(isatty(fd));
+}
+
+int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
+{
+	if (pollfds_num == pollfds_size) {
+		if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
+			/* return min size needed for new pollfds area */
+			return((pollfds_size + 1) * sizeof(pollfds[0]));
+		}
+
+		if(pollfds != NULL){
+			memcpy(tmp_pfd, pollfds,
+			       sizeof(pollfds[0]) * pollfds_size);
+			/* remove old pollfds */
+			kfree(pollfds);
+		}
+		pollfds = tmp_pfd;
+		pollfds_size++;
+	} else {
+		/* remove not used tmp_pfd */
+		if (tmp_pfd != NULL)
+			kfree(tmp_pfd);
+	}
+
+	pollfds[pollfds_num] = ((struct pollfd) { .fd 	= fd,
+						  .events 	= events,
+						  .revents 	= 0 });
+	pollfds_num++;
+
+	return(0);
+}
+
+void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
+		struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
+{
+	struct irq_fd **prev;
+	int i = 0;
+
+	prev = &active_fds;
+	while(*prev != NULL){
+		if((*test)(*prev, arg)){
+			struct irq_fd *old_fd = *prev;
+			if((pollfds[i].fd != -1) &&
+			   (pollfds[i].fd != (*prev)->fd)){
+				printk("os_free_irq_by_cb - mismatch between "
+				       "active_fds and pollfds, fd %d vs %d\n",
+				       (*prev)->fd, pollfds[i].fd);
+				goto out;
+			}
+
+			pollfds_num--;
+
+			/* This moves the *whole* array after pollfds[i]
+			 * (though it doesn't spot as such)!
+			 */
+
+			memmove(&pollfds[i], &pollfds[i + 1],
+			       (pollfds_num - i) * sizeof(pollfds[0]));
+			if(*last_irq_ptr2 == &old_fd->next)
+				*last_irq_ptr2 = prev;
+
+			*prev = (*prev)->next;
+			if(old_fd->type == IRQ_WRITE)
+				ignore_sigio_fd(old_fd->fd);
+			kfree(old_fd);
+			continue;
+		}
+		prev = &(*prev)->next;
+		i++;
+	}
+ out:
+	return;
+}
+
+
+int os_get_pollfd(int i)
+{
+	return(pollfds[i].fd);
+}
+
+void os_set_pollfd(int i, int fd)
+{
+	pollfds[i].fd = fd;
+}
+
+void os_set_ioignore(void)
+{
+	set_handler(SIGIO, SIG_IGN, 0, -1);
+}
+
+void init_irq_signals(int on_sigstack)
+{
+	__sighandler_t h;
+	int flags;
+
+	flags = on_sigstack ? SA_ONSTACK : 0;
+	if(timer_irq_inited) h = (__sighandler_t) alarm_handler;
+	else h = boot_timer_handler;
+
+	set_handler(SIGVTALRM, h, flags | SA_RESTART,
+		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
+	set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
+		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
+	signal(SIGWINCH, SIG_IGN);
+}
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
new file mode 100644
index 000000000000..9ba942947146
--- /dev/null
+++ b/arch/um/os-Linux/sigio.c
@@ -0,0 +1,323 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <termios.h>
+#include <pty.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_util.h"
+#include "user_util.h"
+#include "sigio.h"
+#include "os.h"
+
+/* Protected by sigio_lock(), also used by sigio_cleanup, which is an
+ * exitcall.
+ */
+static int write_sigio_pid = -1;
+
+/* 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.
+ */
+#define SIGIO_FDS_INIT {-1, -1}
+
+static int write_sigio_fds[2] = SIGIO_FDS_INIT;
+static int sigio_private[2] = SIGIO_FDS_INIT;
+
+struct pollfds {
+	struct pollfd *poll;
+	int size;
+	int used;
+};
+
+/* Protected by sigio_lock().  Used by the sigio thread, but the UML thread
+ * synchronizes with it.
+ */
+struct pollfds current_poll = {
+	.poll  		= NULL,
+	.size 		= 0,
+	.used 		= 0
+};
+
+struct pollfds next_poll = {
+	.poll  		= NULL,
+	.size 		= 0,
+	.used 		= 0
+};
+
+static int write_sigio_thread(void *unused)
+{
+	struct pollfds *fds, tmp;
+	struct pollfd *p;
+	int i, n, respond_fd;
+	char c;
+
+        signal(SIGWINCH, SIG_IGN);
+	fds = &current_poll;
+	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);
+		}
+		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 : "
+					       "read failed, err = %d\n", -n);
+				tmp = current_poll;
+				current_poll = next_poll;
+				next_poll = tmp;
+				respond_fd = sigio_private[1];
+			}
+			else {
+				respond_fd = write_sigio_fds[1];
+				fds->used--;
+				memmove(&fds->poll[i], &fds->poll[i + 1],
+					(fds->used - i) * sizeof(*fds->poll));
+			}
+
+			n = os_write_file(respond_fd, &c, sizeof(c));
+			if(n != sizeof(c))
+				printk("write_sigio_thread : write failed, "
+				       "err = %d\n", -n);
+		}
+	}
+
+	return 0;
+}
+
+static int need_poll(int n)
+{
+	if(n <= next_poll.size){
+		next_poll.used = n;
+		return(0);
+	}
+	kfree(next_poll.poll);
+	next_poll.poll = um_kmalloc_atomic(n * sizeof(struct pollfd));
+	if(next_poll.poll == NULL){
+		printk("need_poll : failed to allocate new pollfds\n");
+		next_poll.size = 0;
+		next_poll.used = 0;
+		return(-1);
+	}
+	next_poll.size = n;
+	next_poll.used = n;
+	return(0);
+}
+
+/* Must be called with sigio_lock held, because it's needed by the marked
+ * critical section. */
+static void update_thread(void)
+{
+	unsigned long flags;
+	int n;
+	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);
+		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);
+		goto fail;
+	}
+
+	set_signals(flags);
+	return;
+ fail:
+	/* Critical section start */
+	if(write_sigio_pid != -1)
+		os_kill_process(write_sigio_pid, 1);
+	write_sigio_pid = -1;
+	close(sigio_private[0]);
+	close(sigio_private[1]);
+	close(write_sigio_fds[0]);
+	close(write_sigio_fds[1]);
+	/* Critical section end */
+	set_signals(flags);
+}
+
+int add_sigio_fd(int fd, int read)
+{
+	int err = 0, i, n, events;
+
+	sigio_lock();
+	for(i = 0; i < current_poll.used; i++){
+		if(current_poll.poll[i].fd == fd)
+			goto out;
+	}
+
+	n = current_poll.used + 1;
+	err = need_poll(n);
+	if(err)
+		goto out;
+
+	for(i = 0; i < current_poll.used; i++)
+		next_poll.poll[i] = current_poll.poll[i];
+
+	if(read) events = POLLIN;
+	else events = POLLOUT;
+
+	next_poll.poll[n - 1] = ((struct pollfd) { .fd  	= fd,
+						   .events 	= events,
+						   .revents 	= 0 });
+	update_thread();
+ out:
+	sigio_unlock();
+	return(err);
+}
+
+int ignore_sigio_fd(int fd)
+{
+	struct pollfd *p;
+	int err = 0, i, n = 0;
+
+	sigio_lock();
+	for(i = 0; i < current_poll.used; i++){
+		if(current_poll.poll[i].fd == fd) break;
+	}
+	if(i == current_poll.used)
+		goto out;
+
+	err = need_poll(current_poll.used - 1);
+	if(err)
+		goto out;
+
+	for(i = 0; i < current_poll.used; i++){
+		p = &current_poll.poll[i];
+		if(p->fd != fd) next_poll.poll[n++] = current_poll.poll[i];
+	}
+	if(n == i){
+		printk("ignore_sigio_fd : fd %d not found\n", fd);
+		err = -1;
+		goto out;
+	}
+
+	update_thread();
+ out:
+	sigio_unlock();
+	return(err);
+}
+
+static struct pollfd *setup_initial_poll(int fd)
+{
+	struct pollfd *p;
+
+	p = um_kmalloc(sizeof(struct pollfd));
+	if (p == NULL) {
+		printk("setup_initial_poll : failed to allocate poll\n");
+		return NULL;
+	}
+	*p = ((struct pollfd) { .fd  	= fd,
+				.events 	= POLLIN,
+				.revents 	= 0 });
+	return p;
+}
+
+void write_sigio_workaround(void)
+{
+	unsigned long stack;
+	struct pollfd *p;
+	int err;
+	int l_write_sigio_fds[2];
+	int l_sigio_private[2];
+	int l_write_sigio_pid;
+
+	/* We call this *tons* of times - and most ones we must just fail. */
+	sigio_lock();
+	l_write_sigio_pid = write_sigio_pid;
+	sigio_unlock();
+
+	if (l_write_sigio_pid != -1)
+		return;
+
+	err = os_pipe(l_write_sigio_fds, 1, 1);
+	if(err < 0){
+		printk("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, "
+		       "err = %d\n", -err);
+		goto out_close1;
+	}
+
+	p = setup_initial_poll(l_sigio_private[1]);
+	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)
+		goto out_free;
+
+	current_poll = ((struct pollfds) { .poll 	= p,
+					   .used 	= 1,
+					   .size 	= 1 });
+
+	if (write_sigio_irq(l_write_sigio_fds[0]))
+		goto out_clear_poll;
+
+	memcpy(write_sigio_fds, l_write_sigio_fds, sizeof(l_write_sigio_fds));
+	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);
+
+	if (write_sigio_pid < 0)
+		goto out_clear;
+
+	sigio_unlock();
+	return;
+
+out_clear:
+	write_sigio_pid = -1;
+	write_sigio_fds[0] = -1;
+	write_sigio_fds[1] = -1;
+	sigio_private[0] = -1;
+	sigio_private[1] = -1;
+out_clear_poll:
+	current_poll = ((struct pollfds) { .poll	= NULL,
+					   .size	= 0,
+					   .used	= 0 });
+out_free:
+	kfree(p);
+	sigio_unlock();
+out_close2:
+	close(l_sigio_private[0]);
+	close(l_sigio_private[1]);
+out_close1:
+	close(l_write_sigio_fds[0]);
+	close(l_write_sigio_fds[1]);
+}
+
+void sigio_cleanup(void)
+{
+	if(write_sigio_pid != -1){
+		os_kill_process(write_sigio_pid, 1);
+		write_sigio_pid = -1;
+	}
+}
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 829d6b0d8b02..32753131f8d8 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -3,6 +3,7 @@
  * Licensed under the GPL
  */
 
+#include <pty.h>
 #include <stdio.h>
 #include <stddef.h>
 #include <stdarg.h>
@@ -539,3 +540,130 @@ int __init parse_iomem(char *str, int *add)
 	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 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 = os_sigio_async(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();
+	check_devanon();
+}
+
diff --git a/arch/um/os-Linux/tt.c b/arch/um/os-Linux/tt.c
index 919d19f11537..5461a065bbb9 100644
--- a/arch/um/os-Linux/tt.c
+++ b/arch/um/os-Linux/tt.c
@@ -110,6 +110,16 @@ int wait_for_stop(int pid, int sig, int cont_type, void *relay)
 	}
 }
 
+void forward_ipi(int fd, int pid)
+{
+	int err;
+
+	err = os_set_owner(fd, pid);
+	if(err < 0)
+		printk("forward_ipi: set_owner failed, fd = %d, me = %d, "
+		       "target = %d, err = %d\n", fd, os_getpid(), pid, -err);
+}
+
 /*
  *-------------------------
  * only for tt mode (will be deleted in future...)
diff --git a/arch/um/os-Linux/tty_log.c b/arch/um/os-Linux/tty_log.c
new file mode 100644
index 000000000000..c6ba56c1560f
--- /dev/null
+++ b/arch/um/os-Linux/tty_log.c
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) and
+ * geoffrey hing <ghing@net.ohio-state.edu>
+ * Licensed under the GPL
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include "init.h"
+#include "user.h"
+#include "kern_util.h"
+#include "os.h"
+
+#define TTY_LOG_DIR "./"
+
+/* Set early in boot and then unchanged */
+static char *tty_log_dir = TTY_LOG_DIR;
+static int tty_log_fd = -1;
+
+#define TTY_LOG_OPEN 1
+#define TTY_LOG_CLOSE 2
+#define TTY_LOG_WRITE 3
+#define TTY_LOG_EXEC 4
+
+#define TTY_READ 1
+#define TTY_WRITE 2
+
+struct tty_log_buf {
+	int what;
+	unsigned long tty;
+	int len;
+	int direction;
+	unsigned long sec;
+	unsigned long usec;
+};
+
+int open_tty_log(void *tty, void *current_tty)
+{
+	struct timeval tv;
+	struct tty_log_buf data;
+	char buf[strlen(tty_log_dir) + sizeof("01234567890-01234567\0")];
+	int fd;
+
+	gettimeofday(&tv, NULL);
+	if(tty_log_fd != -1){
+		data = ((struct tty_log_buf) { .what 	= TTY_LOG_OPEN,
+					       .tty  = (unsigned long) tty,
+					       .len  = sizeof(current_tty),
+					       .direction = 0,
+					       .sec = tv.tv_sec,
+					       .usec = tv.tv_usec } );
+		os_write_file(tty_log_fd, &data, sizeof(data));
+		os_write_file(tty_log_fd, &current_tty, data.len);
+		return(tty_log_fd);
+	}
+
+	sprintf(buf, "%s/%0u-%0u", tty_log_dir, (unsigned int) tv.tv_sec,
+ 		(unsigned int) tv.tv_usec);
+
+	fd = os_open_file(buf, of_append(of_create(of_rdwr(OPENFLAGS()))),
+			  0644);
+	if(fd < 0){
+		printk("open_tty_log : couldn't open '%s', errno = %d\n",
+		       buf, -fd);
+	}
+	return(fd);
+}
+
+void close_tty_log(int fd, void *tty)
+{
+	struct tty_log_buf data;
+	struct timeval tv;
+
+	if(tty_log_fd != -1){
+		gettimeofday(&tv, NULL);
+		data = ((struct tty_log_buf) { .what 	= TTY_LOG_CLOSE,
+					       .tty  = (unsigned long) tty,
+					       .len  = 0,
+					       .direction = 0,
+					       .sec = tv.tv_sec,
+					       .usec = tv.tv_usec } );
+		os_write_file(tty_log_fd, &data, sizeof(data));
+		return;
+	}
+	os_close_file(fd);
+}
+
+static int log_chunk(int fd, const char *buf, int len)
+{
+	int total = 0, try, missed, n;
+	char chunk[64];
+
+	while(len > 0){
+		try = (len > sizeof(chunk)) ? sizeof(chunk) : len;
+		missed = copy_from_user_proc(chunk, (char *) buf, try);
+		try -= missed;
+		n = os_write_file(fd, chunk, try);
+		if(n != try) {
+			if(n < 0)
+				return(n);
+			return(-EIO);
+		}
+		if(missed != 0)
+			return(-EFAULT);
+
+		len -= try;
+		total += try;
+		buf += try;
+	}
+
+	return(total);
+}
+
+int write_tty_log(int fd, const char *buf, int len, void *tty, int is_read)
+{
+	struct timeval tv;
+	struct tty_log_buf data;
+	int direction;
+
+	if(fd == tty_log_fd){
+		gettimeofday(&tv, NULL);
+		direction = is_read ? TTY_READ : TTY_WRITE;
+		data = ((struct tty_log_buf) { .what 	= TTY_LOG_WRITE,
+					       .tty  = (unsigned long) tty,
+					       .len  = len,
+					       .direction = direction,
+					       .sec = tv.tv_sec,
+					       .usec = tv.tv_usec } );
+		os_write_file(tty_log_fd, &data, sizeof(data));
+	}
+
+	return(log_chunk(fd, buf, len));
+}
+
+void log_exec(char **argv, void *tty)
+{
+	struct timeval tv;
+	struct tty_log_buf data;
+	char **ptr,*arg;
+	int len;
+
+	if(tty_log_fd == -1) return;
+
+	gettimeofday(&tv, NULL);
+
+	len = 0;
+	for(ptr = argv; ; ptr++){
+		if(copy_from_user_proc(&arg, ptr, sizeof(arg)))
+			return;
+		if(arg == NULL) break;
+		len += strlen_user_proc(arg);
+	}
+
+	data = ((struct tty_log_buf) { .what 	= TTY_LOG_EXEC,
+				       .tty  = (unsigned long) tty,
+				       .len  = len,
+				       .direction = 0,
+				       .sec = tv.tv_sec,
+				       .usec = tv.tv_usec } );
+	os_write_file(tty_log_fd, &data, sizeof(data));
+
+	for(ptr = argv; ; ptr++){
+		if(copy_from_user_proc(&arg, ptr, sizeof(arg)))
+			return;
+		if(arg == NULL) break;
+		log_chunk(tty_log_fd, arg, strlen_user_proc(arg));
+	}
+}
+
+extern void register_tty_logger(int (*opener)(void *, void *),
+				int (*writer)(int, const char *, int,
+					      void *, int),
+				void (*closer)(int, void *));
+
+static int register_logger(void)
+{
+	register_tty_logger(open_tty_log, write_tty_log, close_tty_log);
+	return(0);
+}
+
+__uml_initcall(register_logger);
+
+static int __init set_tty_log_dir(char *name, int *add)
+{
+	tty_log_dir = name;
+	return 0;
+}
+
+__uml_setup("tty_log_dir=", set_tty_log_dir,
+"tty_log_dir=<directory>\n"
+"    This is used to specify the directory where the logs of all pty\n"
+"    data from this UML machine will be written.\n\n"
+);
+
+static int __init set_tty_log_fd(char *name, int *add)
+{
+	char *end;
+
+	tty_log_fd = strtoul(name, &end, 0);
+	if((*end != '\0') || (end == name)){
+		printf("set_tty_log_fd - strtoul failed on '%s'\n", name);
+		tty_log_fd = -1;
+	}
+
+	*add = 0;
+	return 0;
+}
+
+__uml_setup("tty_log_fd=", set_tty_log_fd,
+"tty_log_fd=<fd>\n"
+"    This is used to specify a preconfigured file descriptor to which all\n"
+"    tty data will be written.  Preconfigure the descriptor with something\n"
+"    like '10>tty_log tty_log_fd=10'.\n\n"
+);
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index ecf107ae5ac8..198e59163288 100644
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -143,8 +143,10 @@ static int not_dead_yet(char *dir)
 		goto out_close;
 	}
 
-	if((kill(p, 0) == 0) || (errno != ESRCH))
+	if((kill(p, 0) == 0) || (errno != ESRCH)){
+		printk("umid \"%s\" is already in use by pid %d\n", umid, p);
 		return 1;
+	}
 
 	err = actually_do_remove(dir);
 	if(err)
@@ -234,33 +236,44 @@ int __init make_umid(void)
 	err = mkdir(tmp, 0777);
 	if(err < 0){
 		err = -errno;
-		if(errno != EEXIST)
+		if(err != -EEXIST)
 			goto err;
 
-		if(not_dead_yet(tmp) < 0)
+		/* 1   -> this umid is already in use
+		 * < 0 -> we couldn't remove the umid directory
+		 * In either case, we can't use this umid, so return -EEXIST.
+		 */
+		if(not_dead_yet(tmp) != 0)
 			goto err;
 
 		err = mkdir(tmp, 0777);
 	}
-	if(err < 0){
-		printk("Failed to create '%s' - err = %d\n", umid, err);
-		goto err_rmdir;
+	if(err){
+		err = -errno;
+		printk("Failed to create '%s' - err = %d\n", umid, -errno);
+		goto err;
 	}
 
 	umid_setup = 1;
 
 	create_pid_file();
 
-	return 0;
-
- err_rmdir:
-	rmdir(tmp);
+	err = 0;
  err:
 	return err;
 }
 
 static int __init make_umid_init(void)
 {
+	if(!make_umid())
+		return 0;
+
+	/* If initializing with the given umid failed, then try again with
+	 * a random one.
+	 */
+	printk("Failed to initialize umid \"%s\", trying with a random umid\n",
+	       umid);
+	*umid = '\0';
 	make_umid();
 
 	return 0;