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-rw-r--r--drivers/char/misc.c41
-rw-r--r--drivers/char/virtio_console.c26
-rw-r--r--drivers/char/xillybus/xillybus_class.c7
-rw-r--r--drivers/char/xillybus/xillyusb.c22
4 files changed, 62 insertions, 34 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index cba19bfdc44d..05727f0daa6b 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -61,7 +61,29 @@ static DEFINE_MUTEX(misc_mtx);
* Assigned numbers, used for dynamic minors
*/
#define DYNAMIC_MINORS 128 /* like dynamic majors */
-static DECLARE_BITMAP(misc_minors, DYNAMIC_MINORS);
+static DEFINE_IDA(misc_minors_ida);
+
+static int misc_minor_alloc(void)
+{
+ int ret;
+
+ ret = ida_alloc_max(&misc_minors_ida, DYNAMIC_MINORS - 1, GFP_KERNEL);
+ if (ret >= 0) {
+ ret = DYNAMIC_MINORS - ret - 1;
+ } else {
+ ret = ida_alloc_range(&misc_minors_ida, MISC_DYNAMIC_MINOR + 1,
+ MINORMASK, GFP_KERNEL);
+ }
+ return ret;
+}
+
+static void misc_minor_free(int minor)
+{
+ if (minor < DYNAMIC_MINORS)
+ ida_free(&misc_minors_ida, DYNAMIC_MINORS - minor - 1);
+ else if (minor > MISC_DYNAMIC_MINOR)
+ ida_free(&misc_minors_ida, minor);
+}
#ifdef CONFIG_PROC_FS
static void *misc_seq_start(struct seq_file *seq, loff_t *pos)
@@ -183,14 +205,13 @@ int misc_register(struct miscdevice *misc)
mutex_lock(&misc_mtx);
if (is_dynamic) {
- int i = find_first_zero_bit(misc_minors, DYNAMIC_MINORS);
+ int i = misc_minor_alloc();
- if (i >= DYNAMIC_MINORS) {
+ if (i < 0) {
err = -EBUSY;
goto out;
}
- misc->minor = DYNAMIC_MINORS - i - 1;
- set_bit(i, misc_minors);
+ misc->minor = i;
} else {
struct miscdevice *c;
@@ -209,10 +230,7 @@ int misc_register(struct miscdevice *misc)
misc, misc->groups, "%s", misc->name);
if (IS_ERR(misc->this_device)) {
if (is_dynamic) {
- int i = DYNAMIC_MINORS - misc->minor - 1;
-
- if (i < DYNAMIC_MINORS && i >= 0)
- clear_bit(i, misc_minors);
+ misc_minor_free(misc->minor);
misc->minor = MISC_DYNAMIC_MINOR;
}
err = PTR_ERR(misc->this_device);
@@ -240,16 +258,13 @@ EXPORT_SYMBOL(misc_register);
void misc_deregister(struct miscdevice *misc)
{
- int i = DYNAMIC_MINORS - misc->minor - 1;
-
if (WARN_ON(list_empty(&misc->list)))
return;
mutex_lock(&misc_mtx);
list_del(&misc->list);
device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));
- if (i < DYNAMIC_MINORS && i >= 0)
- clear_bit(i, misc_minors);
+ misc_minor_free(misc->minor);
mutex_unlock(&misc_mtx);
}
EXPORT_SYMBOL(misc_deregister);
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 9fa3c76a267f..6a821118d553 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -13,6 +13,7 @@
#include <linux/fs.h>
#include <linux/splice.h>
#include <linux/pagemap.h>
+#include <linux/idr.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/poll.h>
@@ -48,22 +49,11 @@ struct ports_driver_data {
/* List of all the devices we're handling */
struct list_head portdevs;
- /*
- * This is used to keep track of the number of hvc consoles
- * spawned by this driver. This number is given as the first
- * argument to hvc_alloc(). To correctly map an initial
- * console spawned via hvc_instantiate to the console being
- * hooked up via hvc_alloc, we need to pass the same vtermno.
- *
- * We also just assume the first console being initialised was
- * the first one that got used as the initial console.
- */
- unsigned int next_vtermno;
-
/* All the console devices handled by this driver */
struct list_head consoles;
};
-static struct ports_driver_data pdrvdata = { .next_vtermno = 1};
+
+static struct ports_driver_data pdrvdata;
static DEFINE_SPINLOCK(pdrvdata_lock);
static DECLARE_COMPLETION(early_console_added);
@@ -89,6 +79,8 @@ struct console {
u32 vtermno;
};
+static DEFINE_IDA(vtermno_ida);
+
struct port_buffer {
char *buf;
@@ -1244,18 +1236,21 @@ static int init_port_console(struct port *port)
* pointers. The final argument is the output buffer size: we
* can do any size, so we put PAGE_SIZE here.
*/
- port->cons.vtermno = pdrvdata.next_vtermno;
+ ret = ida_alloc_min(&vtermno_ida, 1, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+ port->cons.vtermno = ret;
port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
if (IS_ERR(port->cons.hvc)) {
ret = PTR_ERR(port->cons.hvc);
dev_err(port->dev,
"error %d allocating hvc for port\n", ret);
port->cons.hvc = NULL;
+ ida_free(&vtermno_ida, port->cons.vtermno);
return ret;
}
spin_lock_irq(&pdrvdata_lock);
- pdrvdata.next_vtermno++;
list_add_tail(&port->cons.list, &pdrvdata.consoles);
spin_unlock_irq(&pdrvdata_lock);
port->guest_connected = true;
@@ -1532,6 +1527,7 @@ static void unplug_port(struct port *port)
list_del(&port->cons.list);
spin_unlock_irq(&pdrvdata_lock);
hvc_remove(port->cons.hvc);
+ ida_free(&vtermno_ida, port->cons.vtermno);
}
remove_port_data(port);
diff --git a/drivers/char/xillybus/xillybus_class.c b/drivers/char/xillybus/xillybus_class.c
index 0f238648dcfe..e9a288e61c15 100644
--- a/drivers/char/xillybus/xillybus_class.c
+++ b/drivers/char/xillybus/xillybus_class.c
@@ -227,14 +227,15 @@ int xillybus_find_inode(struct inode *inode,
break;
}
- mutex_unlock(&unit_mutex);
-
- if (!unit)
+ if (!unit) {
+ mutex_unlock(&unit_mutex);
return -ENODEV;
+ }
*private_data = unit->private_data;
*index = minor - unit->lowest_minor;
+ mutex_unlock(&unit_mutex);
return 0;
}
EXPORT_SYMBOL(xillybus_find_inode);
diff --git a/drivers/char/xillybus/xillyusb.c b/drivers/char/xillybus/xillyusb.c
index 39bcbfd908b4..5a5afa14ca8c 100644
--- a/drivers/char/xillybus/xillyusb.c
+++ b/drivers/char/xillybus/xillyusb.c
@@ -184,6 +184,14 @@ struct xillyusb_dev {
struct mutex process_in_mutex; /* synchronize wakeup_all() */
};
+/*
+ * kref_mutex is used in xillyusb_open() to prevent the xillyusb_dev
+ * struct from being freed during the gap between being found by
+ * xillybus_find_inode() and having its reference count incremented.
+ */
+
+static DEFINE_MUTEX(kref_mutex);
+
/* FPGA to host opcodes */
enum {
OPCODE_DATA = 0,
@@ -1237,9 +1245,16 @@ static int xillyusb_open(struct inode *inode, struct file *filp)
int rc;
int index;
+ mutex_lock(&kref_mutex);
+
rc = xillybus_find_inode(inode, (void **)&xdev, &index);
- if (rc)
+ if (rc) {
+ mutex_unlock(&kref_mutex);
return rc;
+ }
+
+ kref_get(&xdev->kref);
+ mutex_unlock(&kref_mutex);
chan = &xdev->channels[index];
filp->private_data = chan;
@@ -1275,8 +1290,6 @@ static int xillyusb_open(struct inode *inode, struct file *filp)
((filp->f_mode & FMODE_WRITE) && chan->open_for_write))
goto unmutex_fail;
- kref_get(&xdev->kref);
-
if (filp->f_mode & FMODE_READ)
chan->open_for_read = 1;
@@ -1413,6 +1426,7 @@ unopen:
return rc;
unmutex_fail:
+ kref_put(&xdev->kref, cleanup_dev);
mutex_unlock(&chan->lock);
return rc;
}
@@ -2227,7 +2241,9 @@ static void xillyusb_disconnect(struct usb_interface *interface)
xdev->dev = NULL;
+ mutex_lock(&kref_mutex);
kref_put(&xdev->kref, cleanup_dev);
+ mutex_unlock(&kref_mutex);
}
static struct usb_driver xillyusb_driver = {
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-20 01:59:15 +0000