Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 431 insertions, 0 deletions

diff --git a/arch/um/kernel/sigio_user.c b/arch/um/kernel/sigio_user.c
new file mode 100644
index 000000000000..668df13d8c9d
--- /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 = &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);
+                }
+        }
+}
+
+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 = &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 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);