qemu/chardev/char-fd.c
zhanghailiang b19456dd0e char: Fix removing wrong GSource that be found by fd_in_tag
We use fd_in_tag to find a GSource, fd_in_tag is return value of
g_source_attach(GSource *source, GMainContext *context), the return
value is unique only in the same context, so we may get the same
values with different 'context' parameters.

It is no problem to find the right fd_in_tag by using
 g_main_context_find_source_by_id(GMainContext *context, guint source_id)
while there is only one default main context.

But colo-compare tries to create/use its own context, and if we pass wrong
'context' parameter with right fd_in_tag, we will find a wrong GSource to handle.
We tried to fix the related codes in commit b43decb015,
but it didn't fix the bug completely, because we still have some codes didn't pass
*right* context parameter for remove_fd_in_watch().

Let's fix it by record the GSource directly instead of fd_in_tag.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1492564532-91680-1-git-send-email-zhang.zhanghailiang@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-03 12:29:40 +02:00

171 lines
4.7 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu/sockets.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "sysemu/char.h"
#include "io/channel-file.h"
#include "char-fd.h"
#include "char-io.h"
/* Called with chr_write_lock held. */
static int fd_chr_write(Chardev *chr, const uint8_t *buf, int len)
{
FDChardev *s = FD_CHARDEV(chr);
return io_channel_send(s->ioc_out, buf, len);
}
static gboolean fd_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
{
Chardev *chr = CHARDEV(opaque);
FDChardev *s = FD_CHARDEV(opaque);
int len;
uint8_t buf[CHR_READ_BUF_LEN];
ssize_t ret;
len = sizeof(buf);
if (len > s->max_size) {
len = s->max_size;
}
if (len == 0) {
return TRUE;
}
ret = qio_channel_read(
chan, (gchar *)buf, len, NULL);
if (ret == 0) {
remove_fd_in_watch(chr);
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
return FALSE;
}
if (ret > 0) {
qemu_chr_be_write(chr, buf, ret);
}
return TRUE;
}
static int fd_chr_read_poll(void *opaque)
{
Chardev *chr = CHARDEV(opaque);
FDChardev *s = FD_CHARDEV(opaque);
s->max_size = qemu_chr_be_can_write(chr);
return s->max_size;
}
static GSource *fd_chr_add_watch(Chardev *chr, GIOCondition cond)
{
FDChardev *s = FD_CHARDEV(chr);
return qio_channel_create_watch(s->ioc_out, cond);
}
static void fd_chr_update_read_handler(Chardev *chr,
GMainContext *context)
{
FDChardev *s = FD_CHARDEV(chr);
remove_fd_in_watch(chr);
if (s->ioc_in) {
chr->gsource = io_add_watch_poll(chr, s->ioc_in,
fd_chr_read_poll,
fd_chr_read, chr,
context);
}
}
static void char_fd_finalize(Object *obj)
{
Chardev *chr = CHARDEV(obj);
FDChardev *s = FD_CHARDEV(obj);
remove_fd_in_watch(chr);
if (s->ioc_in) {
object_unref(OBJECT(s->ioc_in));
}
if (s->ioc_out) {
object_unref(OBJECT(s->ioc_out));
}
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
}
int qmp_chardev_open_file_source(char *src, int flags, Error **errp)
{
int fd = -1;
TFR(fd = qemu_open(src, flags, 0666));
if (fd == -1) {
error_setg_file_open(errp, errno, src);
}
return fd;
}
/* open a character device to a unix fd */
void qemu_chr_open_fd(Chardev *chr,
int fd_in, int fd_out)
{
FDChardev *s = FD_CHARDEV(chr);
char *name;
s->ioc_in = QIO_CHANNEL(qio_channel_file_new_fd(fd_in));
name = g_strdup_printf("chardev-file-in-%s", chr->label);
qio_channel_set_name(QIO_CHANNEL(s->ioc_in), name);
g_free(name);
s->ioc_out = QIO_CHANNEL(qio_channel_file_new_fd(fd_out));
name = g_strdup_printf("chardev-file-out-%s", chr->label);
qio_channel_set_name(QIO_CHANNEL(s->ioc_out), name);
g_free(name);
qemu_set_nonblock(fd_out);
s->chr = chr;
}
static void char_fd_class_init(ObjectClass *oc, void *data)
{
ChardevClass *cc = CHARDEV_CLASS(oc);
cc->chr_add_watch = fd_chr_add_watch;
cc->chr_write = fd_chr_write;
cc->chr_update_read_handler = fd_chr_update_read_handler;
}
static const TypeInfo char_fd_type_info = {
.name = TYPE_CHARDEV_FD,
.parent = TYPE_CHARDEV,
.instance_size = sizeof(FDChardev),
.instance_finalize = char_fd_finalize,
.class_init = char_fd_class_init,
.abstract = true,
};
static void register_types(void)
{
type_register_static(&char_fd_type_info);
}
type_init(register_types);