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firewire: cdev: use mutex for phy receiver list

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In the cdev layer, the list of phy packet receivers is currently
protected by a spinlock. This requires GFP_ATOMIC for memory allocation
when enumerating the list in fw_cdev_handle_phy_packet(). However, the
function is guaranteed to be invoked in process context, so GFP_KERNEL
can be used by switching from the spinlock to a mutex.

Link: https://lore.kernel.org/r/20260920083659.191855-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit is contained in:
Takashi Sakamoto 2026-09-20 17:36:56 +09:00
parent 567a656d92
commit a520ce89fc
1 changed files with 6 additions and 14 deletions
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20
drivers/firewire/core-cdev.c
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@ -47,7 +47,7 @@
#define FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW 5
#define FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP 6
static DEFINE_SPINLOCK(phy_receiver_list_lock);
static DEFINE_MUTEX(phy_receiver_list_mutex);
static LIST_HEAD(phy_receiver_list);
struct client {
@ -1761,9 +1761,7 @@ static int ioctl_receive_phy_packets(struct client *client, union ioctl_arg *arg
if (!client->device->is_local)
return -ENOSYS;
// NOTE: This can be without irq when we can guarantee that __fw_send_request() for local
// destination never runs in any type of IRQ context.
scoped_guard(spinlock_irq, &phy_receiver_list_lock)
scoped_guard(mutex, &phy_receiver_list_mutex)
list_move_tail(&client->phy_receiver_link, &phy_receiver_list);
client->phy_receiver_closure = a->closure;
@ -1775,18 +1773,14 @@ void fw_cdev_handle_phy_packet(struct fw_card *card, struct fw_packet *p)
{
struct client *client;
// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for local
// destination never runs in any type of IRQ context.
guard(spinlock_irqsave)(&phy_receiver_list_lock);
guard(mutex)(&phy_receiver_list_mutex);
list_for_each_entry(client, &phy_receiver_list, phy_receiver_link) {
struct inbound_phy_packet_event *e;
if (client->device->card != card)
continue;
e = kmalloc(sizeof(*e) + 8, GFP_ATOMIC);
if (e == NULL)
struct inbound_phy_packet_event *e = kmalloc(sizeof(*e) + 8, GFP_KERNEL);
if (!e)
break;
if (client->version < FW_CDEV_VERSION_EVENT_ASYNC_TSTAMP) {
@ -1953,9 +1947,7 @@ static int fw_device_op_release(struct inode *inode, struct file *file)
struct client_resource *resource;
unsigned long index;
// NOTE: This can be without irq when we can guarantee that __fw_send_request() for local
// destination never runs in any type of IRQ context.
scoped_guard(spinlock_irq, &phy_receiver_list_lock)
scoped_guard(mutex, &phy_receiver_list_mutex)
list_del(&client->phy_receiver_link);
scoped_guard(mutex, &client->device->client_list_mutex)