Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/um/kernel/sigio_user.c b/arch/um/kernel/sigio_user.c
new file mode 100644
index 0000000..668df13
--- /dev/null
+++ b/arch/um/kernel/sigio_user.c
@@ -0,0 +1,431 @@
+/*
+ * 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 "helper.h"
+#include "os.h"
+
+/* 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;
+
+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;
+}
+
+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);
+
+ os_close_file(master);
+ os_close_file(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...");
+
+ os_close_file(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);
+}
+
+/* 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.
+ */
+static int write_sigio_fds[2] = { -1, -1 };
+static int sigio_private[2] = { -1, -1 };
+
+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;
+
+ fds = ¤t_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);
+ }
+ }
+}
+
+static int need_poll(int n)
+{
+ if(n <= next_poll.size){
+ next_poll.used = n;
+ return(0);
+ }
+ if(next_poll.poll != NULL) 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;
+ os_close_file(sigio_private[0]);
+ os_close_file(sigio_private[1]);
+ os_close_file(write_sigio_fds[0]);
+ os_close_file(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 = ¤t_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 int 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(-1);
+ }
+ *p = ((struct pollfd) { .fd = fd,
+ .events = POLLIN,
+ .revents = 0 });
+ current_poll = ((struct pollfds) { .poll = p,
+ .used = 1,
+ .size = 1 });
+ return(0);
+}
+
+void write_sigio_workaround(void)
+{
+ unsigned long stack;
+ int err;
+
+ sigio_lock();
+ if(write_sigio_pid != -1)
+ goto out;
+
+ err = os_pipe(write_sigio_fds, 1, 1);
+ if(err < 0){
+ printk("write_sigio_workaround - os_pipe 1 failed, "
+ "err = %d\n", -err);
+ goto out;
+ }
+ err = os_pipe(sigio_private, 1, 1);
+ if(err < 0){
+ printk("write_sigio_workaround - os_pipe 2 failed, "
+ "err = %d\n", -err);
+ goto out_close1;
+ }
+ if(setup_initial_poll(sigio_private[1]))
+ goto out_close2;
+
+ write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
+ CLONE_FILES | CLONE_VM, &stack, 0);
+
+ if(write_sigio_pid < 0) goto out_close2;
+
+ if(write_sigio_irq(write_sigio_fds[0]))
+ goto out_kill;
+
+ out:
+ sigio_unlock();
+ return;
+
+ out_kill:
+ os_kill_process(write_sigio_pid, 1);
+ write_sigio_pid = -1;
+ out_close2:
+ os_close_file(sigio_private[0]);
+ os_close_file(sigio_private[1]);
+ out_close1:
+ os_close_file(write_sigio_fds[0]);
+ os_close_file(write_sigio_fds[1]);
+ sigio_unlock();
+}
+
+int read_sigio_fd(int fd)
+{
+ int n;
+ char c;
+
+ n = os_read_file(fd, &c, sizeof(c));
+ if(n != sizeof(c)){
+ if(n < 0) {
+ printk("read_sigio_fd - read failed, err = %d\n", -n);
+ return(n);
+ }
+ else {
+ printk("read_sigio_fd - short read, bytes = %d\n", n);
+ return(-EIO);
+ }
+ }
+ return(n);
+}
+
+static void sigio_cleanup(void)
+{
+ if (write_sigio_pid != -1) {
+ os_kill_process(write_sigio_pid, 1);
+ write_sigio_pid = -1;
+ }
+}
+
+__uml_exitcall(sigio_cleanup);