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[PATCH] uml: move sigio_user.c to os-Linux/sigio.c

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The serial UML OS-abstraction layer patch (um/kernel dir).

This moves sigio_user.c to os-Linux dir

Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Jeff Dike
2006-03-27 01:14:33 -08:00
committed by Linus Torvalds
parent 8e367065ee
commit f206aabb03
6 changed files with 19 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
arch/um/os-Linux/Makefile
View File

@@ -3,14 +3,15 @@
# Licensed under the GPL
#
obj-y = aio.o elf_aux.o file.o helper.o irq.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/
USER_OBJS := aio.o elf_aux.o file.o helper.o irq.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
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

324
arch/um/os-Linux/sigio.c Normal file
View File

@@ -0,0 +1,324 @@
/*
* 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.
*/
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;
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_unlock;
write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
CLONE_FILES | CLONE_VM, &stack, 0);
if (write_sigio_pid < 0)
goto out_clear;
if (write_sigio_irq(l_write_sigio_fds[0]))
goto out_kill;
/* Success, finally. */
memcpy(write_sigio_fds, l_write_sigio_fds, sizeof(l_write_sigio_fds));
memcpy(sigio_private, l_sigio_private, sizeof(l_sigio_private));
current_poll = ((struct pollfds) { .poll = p,
.used = 1,
.size = 1 });
sigio_unlock();
return;
out_kill:
l_write_sigio_pid = write_sigio_pid;
write_sigio_pid = -1;
sigio_unlock();
/* Going to call waitpid, avoid holding the lock. */
os_kill_process(l_write_sigio_pid, 1);
goto out_free;
out_clear:
write_sigio_pid = -1;
out_unlock:
sigio_unlock();
out_free:
kfree(p);
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]);
return;
}
void sigio_cleanup(void)
{
if(write_sigio_pid != -1){
os_kill_process(write_sigio_pid, 1);
write_sigio_pid = -1;
}
}