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Diffstat (limited to 'arch')
-rw-r--r--arch/um/include/os.h1
-rw-r--r--arch/um/kernel/irq.c34
-rw-r--r--arch/um/os-Linux/sigio.c103
3 files changed, 67 insertions, 71 deletions
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 5316e8a4a4f..c73dfa78f94 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -329,6 +329,7 @@ extern void os_set_ioignore(void);
extern void init_irq_signals(int on_sigstack);
/* sigio.c */
+extern int add_sigio_fd(int fd);
extern int ignore_sigio_fd(int fd);
extern void maybe_sigio_broken(int fd, int read);
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 589c69a7504..ce7f233fc49 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -142,19 +142,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
.events = events,
.current_events = 0 } );
- /* Critical section - locked by a spinlock because this stuff can
- * be changed from interrupt handlers. The stuff above is done
- * outside the lock because it allocates memory.
- */
-
- /* Actually, it only looks like it can be called from interrupt
- * context. The culprit is reactivate_fd, which calls
- * maybe_sigio_broken, which calls write_sigio_workaround,
- * which calls activate_fd. However, write_sigio_workaround should
- * only be called once, at boot time. That would make it clear that
- * this is called only from process context, and can be locked with
- * a semaphore.
- */
spin_lock_irqsave(&irq_lock, flags);
for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
@@ -165,7 +152,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
}
}
- /*-------------*/
if (type == IRQ_WRITE)
fd = -1;
@@ -198,7 +184,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
spin_lock_irqsave(&irq_lock, flags);
}
- /*-------------*/
*last_irq_ptr = new_fd;
last_irq_ptr = &new_fd->next;
@@ -210,14 +195,14 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
*/
maybe_sigio_broken(fd, (type == IRQ_READ));
- return(0);
+ return 0;
out_unlock:
spin_unlock_irqrestore(&irq_lock, flags);
out_kfree:
kfree(new_fd);
out:
- return(err);
+ return err;
}
static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
@@ -302,10 +287,7 @@ void reactivate_fd(int fd, int irqnum)
os_set_pollfd(i, irq->fd);
spin_unlock_irqrestore(&irq_lock, flags);
- /* This calls activate_fd, so it has to be outside the critical
- * section.
- */
- maybe_sigio_broken(fd, (irq->type == IRQ_READ));
+ add_sigio_fd(fd);
}
void deactivate_fd(int fd, int irqnum)
@@ -316,11 +298,15 @@ void deactivate_fd(int fd, int irqnum)
spin_lock_irqsave(&irq_lock, flags);
irq = find_irq_by_fd(fd, irqnum, &i);
- if (irq == NULL)
- goto out;
+ if(irq == NULL){
+ spin_unlock_irqrestore(&irq_lock, flags);
+ return;
+ }
+
os_set_pollfd(i, -1);
- out:
spin_unlock_irqrestore(&irq_lock, flags);
+
+ ignore_sigio_fd(fd);
}
int deactivate_all_fds(void)
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 0ecac563c7b..f6457765b17 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -43,17 +43,9 @@ struct pollfds {
/* Protected by sigio_lock(). Used by the sigio thread, but the UML thread
* synchronizes with it.
*/
-static struct pollfds current_poll = {
- .poll = NULL,
- .size = 0,
- .used = 0
-};
-
-static struct pollfds next_poll = {
- .poll = NULL,
- .size = 0,
- .used = 0
-};
+static struct pollfds current_poll;
+static struct pollfds next_poll;
+static struct pollfds all_sigio_fds;
static int write_sigio_thread(void *unused)
{
@@ -78,7 +70,8 @@ static int write_sigio_thread(void *unused)
n = os_read_file(sigio_private[1], &c, sizeof(c));
if(n != sizeof(c))
printk("write_sigio_thread : "
- "read failed, err = %d\n", -n);
+ "read on socket failed, "
+ "err = %d\n", -n);
tmp = current_poll;
current_poll = next_poll;
next_poll = tmp;
@@ -93,35 +86,36 @@ static int write_sigio_thread(void *unused)
n = os_write_file(respond_fd, &c, sizeof(c));
if(n != sizeof(c))
- printk("write_sigio_thread : write failed, "
- "err = %d\n", -n);
+ printk("write_sigio_thread : write on socket "
+ "failed, err = %d\n", -n);
}
}
return 0;
}
-static int need_poll(int n)
+static int need_poll(struct pollfds *polls, int n)
{
- if(n <= next_poll.size){
- next_poll.used = n;
- return(0);
+ if(n <= polls->size){
+ polls->used = n;
+ return 0;
}
- kfree(next_poll.poll);
- next_poll.poll = um_kmalloc_atomic(n * sizeof(struct pollfd));
- if(next_poll.poll == NULL){
+ kfree(polls->poll);
+ polls->poll = um_kmalloc_atomic(n * sizeof(struct pollfd));
+ if(polls->poll == NULL){
printk("need_poll : failed to allocate new pollfds\n");
- next_poll.size = 0;
- next_poll.used = 0;
- return(-1);
+ polls->size = 0;
+ polls->used = 0;
+ return -ENOMEM;
}
- next_poll.size = n;
- next_poll.used = n;
- return(0);
+ polls->size = n;
+ polls->used = n;
+ return 0;
}
/* Must be called with sigio_lock held, because it's needed by the marked
- * critical section. */
+ * critical section.
+ */
static void update_thread(void)
{
unsigned long flags;
@@ -156,34 +150,39 @@ static void update_thread(void)
set_signals(flags);
}
-static int add_sigio_fd(int fd, int read)
+int add_sigio_fd(int fd)
{
- int err = 0, i, n, events;
+ struct pollfd *p;
+ int err = 0, i, n;
sigio_lock();
+ for(i = 0; i < all_sigio_fds.used; i++){
+ if(all_sigio_fds.poll[i].fd == fd)
+ break;
+ }
+ if(i == all_sigio_fds.used)
+ goto out;
+
+ p = &all_sigio_fds.poll[i];
+
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);
+ err = need_poll(&next_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 });
+ next_poll.poll[n - 1] = *p;
update_thread();
out:
sigio_unlock();
- return(err);
+ return err;
}
int ignore_sigio_fd(int fd)
@@ -205,18 +204,14 @@ int ignore_sigio_fd(int fd)
if(i == current_poll.used)
goto out;
- err = need_poll(current_poll.used - 1);
+ err = need_poll(&next_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;
+ if(p->fd != fd)
+ next_poll.poll[n++] = *p;
}
update_thread();
@@ -234,7 +229,7 @@ static struct pollfd *setup_initial_poll(int fd)
printk("setup_initial_poll : failed to allocate poll\n");
return NULL;
}
- *p = ((struct pollfd) { .fd = fd,
+ *p = ((struct pollfd) { .fd = fd,
.events = POLLIN,
.revents = 0 });
return p;
@@ -323,6 +318,8 @@ out_close1:
void maybe_sigio_broken(int fd, int read)
{
+ int err;
+
if(!isatty(fd))
return;
@@ -330,7 +327,19 @@ void maybe_sigio_broken(int fd, int read)
return;
write_sigio_workaround();
- add_sigio_fd(fd, read);
+
+ sigio_lock();
+ err = need_poll(&all_sigio_fds, all_sigio_fds.used + 1);
+ if(err){
+ printk("maybe_sigio_broken - failed to add pollfd\n");
+ goto out;
+ }
+ all_sigio_fds.poll[all_sigio_fds.used++] =
+ ((struct pollfd) { .fd = fd,
+ .events = read ? POLLIN : POLLOUT,
+ .revents = 0 });
+out:
+ sigio_unlock();
}
static void sigio_cleanup(void)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-26 20:33:39 +0000