Merge tag 'for-linus-6.11-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

 - some trivial cleanups

 - a fix for the Xen timer

 - add boot time selectable debug capability to the Xen multicall
   handling

 - two fixes for the recently added Xen irqfd handling

* tag 'for-linus-6.11-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: remove deprecated xen_nopvspin boot parameter
  x86/xen: eliminate some private header files
  x86/xen: make some functions static
  xen: make multicall debug boot time selectable
  xen/arm: Convert comma to semicolon
  xen: privcmd: Fix possible access to a freed kirqfd instance
  xen: privcmd: Switch from mutex to spinlock for irqfds
  xen: add missing MODULE_DESCRIPTION() macros
  x86/xen: Convert comma to semicolon
  x86/xen/time: Reduce Xen timer tick
  xen/manage: Constify struct shutdown_handler

5 files changed, 29 insertions, 12 deletions

diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index f6a2216c2c87..9b7fcc7dbb38 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -729,4 +729,5 @@ static void __exit evtchn_cleanup(void)
 module_init(evtchn_init);
 module_exit(evtchn_cleanup);
 
+MODULE_DESCRIPTION("Xen /dev/xen/evtchn device driver");
 MODULE_LICENSE("GPL");
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index c16df629907e..b4b4ebed68da 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -208,7 +208,7 @@ static void do_reboot(void)
 	orderly_reboot();
 }
 
-static struct shutdown_handler shutdown_handlers[] = {
+static const struct shutdown_handler shutdown_handlers[] = {
 	{ "poweroff",	true,	do_poweroff },
 	{ "halt",	false,	do_poweroff },
 	{ "reboot",	true,	do_reboot   },
diff --git a/drivers/xen/privcmd-buf.c b/drivers/xen/privcmd-buf.c
index 2fa10ca5be14..0f0dad427d7e 100644
--- a/drivers/xen/privcmd-buf.c
+++ b/drivers/xen/privcmd-buf.c
@@ -19,6 +19,7 @@
 
 #include "privcmd.h"
 
+MODULE_DESCRIPTION("Xen Mmap of hypercall buffers");
 MODULE_LICENSE("GPL");
 
 struct privcmd_buf_private {
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 67dfa4778864..9563650dfbaf 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -17,6 +17,7 @@
 #include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/srcu.h>
 #include <linux/string.h>
 #include <linux/workqueue.h>
 #include <linux/errno.h>
@@ -48,6 +49,7 @@
 
 #include "privcmd.h"
 
+MODULE_DESCRIPTION("Xen hypercall passthrough driver");
 MODULE_LICENSE("GPL");
 
 #define PRIV_VMA_LOCKED ((void *)1)
@@ -845,7 +847,8 @@ out:
 #ifdef CONFIG_XEN_PRIVCMD_EVENTFD
 /* Irqfd support */
 static struct workqueue_struct *irqfd_cleanup_wq;
-static DEFINE_MUTEX(irqfds_lock);
+static DEFINE_SPINLOCK(irqfds_lock);
+DEFINE_STATIC_SRCU(irqfds_srcu);
 static LIST_HEAD(irqfds_list);
 
 struct privcmd_kernel_irqfd {
@@ -873,6 +876,9 @@ static void irqfd_shutdown(struct work_struct *work)
 		container_of(work, struct privcmd_kernel_irqfd, shutdown);
 	u64 cnt;
 
+	/* Make sure irqfd has been initialized in assign path */
+	synchronize_srcu(&irqfds_srcu);
+
 	eventfd_ctx_remove_wait_queue(kirqfd->eventfd, &kirqfd->wait, &cnt);
 	eventfd_ctx_put(kirqfd->eventfd);
 	kfree(kirqfd);
@@ -909,9 +915,11 @@ irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
 		irqfd_inject(kirqfd);
 
 	if (flags & EPOLLHUP) {
-		mutex_lock(&irqfds_lock);
+		unsigned long flags;
+
+		spin_lock_irqsave(&irqfds_lock, flags);
 		irqfd_deactivate(kirqfd);
-		mutex_unlock(&irqfds_lock);
+		spin_unlock_irqrestore(&irqfds_lock, flags);
 	}
 
 	return 0;
@@ -929,10 +937,11 @@ irqfd_poll_func(struct file *file, wait_queue_head_t *wqh, poll_table *pt)
 static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
 {
 	struct privcmd_kernel_irqfd *kirqfd, *tmp;
+	unsigned long flags;
 	__poll_t events;
 	struct fd f;
 	void *dm_op;
-	int ret;
+	int ret, idx;
 
 	kirqfd = kzalloc(sizeof(*kirqfd) + irqfd->size, GFP_KERNEL);
 	if (!kirqfd)
@@ -968,18 +977,19 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
 	init_waitqueue_func_entry(&kirqfd->wait, irqfd_wakeup);
 	init_poll_funcptr(&kirqfd->pt, irqfd_poll_func);
 
-	mutex_lock(&irqfds_lock);
+	spin_lock_irqsave(&irqfds_lock, flags);
 
 	list_for_each_entry(tmp, &irqfds_list, list) {
 		if (kirqfd->eventfd == tmp->eventfd) {
 			ret = -EBUSY;
-			mutex_unlock(&irqfds_lock);
+			spin_unlock_irqrestore(&irqfds_lock, flags);
 			goto error_eventfd;
 		}
 	}
 
+	idx = srcu_read_lock(&irqfds_srcu);
 	list_add_tail(&kirqfd->list, &irqfds_list);
-	mutex_unlock(&irqfds_lock);
+	spin_unlock_irqrestore(&irqfds_lock, flags);
 
 	/*
 	 * Check if there was an event already pending on the eventfd before we
@@ -989,6 +999,8 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
 	if (events & EPOLLIN)
 		irqfd_inject(kirqfd);
 
+	srcu_read_unlock(&irqfds_srcu, idx);
+
 	/*
 	 * Do not drop the file until the kirqfd is fully initialized, otherwise
 	 * we might race against the EPOLLHUP.
@@ -1011,12 +1023,13 @@ static int privcmd_irqfd_deassign(struct privcmd_irqfd *irqfd)
 {
 	struct privcmd_kernel_irqfd *kirqfd;
 	struct eventfd_ctx *eventfd;
+	unsigned long flags;
 
 	eventfd = eventfd_ctx_fdget(irqfd->fd);
 	if (IS_ERR(eventfd))
 		return PTR_ERR(eventfd);
 
-	mutex_lock(&irqfds_lock);
+	spin_lock_irqsave(&irqfds_lock, flags);
 
 	list_for_each_entry(kirqfd, &irqfds_list, list) {
 		if (kirqfd->eventfd == eventfd) {
@@ -1025,7 +1038,7 @@ static int privcmd_irqfd_deassign(struct privcmd_irqfd *irqfd)
 		}
 	}
 
-	mutex_unlock(&irqfds_lock);
+	spin_unlock_irqrestore(&irqfds_lock, flags);
 
 	eventfd_ctx_put(eventfd);
 
@@ -1073,13 +1086,14 @@ static int privcmd_irqfd_init(void)
 static void privcmd_irqfd_exit(void)
 {
 	struct privcmd_kernel_irqfd *kirqfd, *tmp;
+	unsigned long flags;
 
-	mutex_lock(&irqfds_lock);
+	spin_lock_irqsave(&irqfds_lock, flags);
 
 	list_for_each_entry_safe(kirqfd, tmp, &irqfds_list, list)
 		irqfd_deactivate(kirqfd);
 
-	mutex_unlock(&irqfds_lock);
+	spin_unlock_irqrestore(&irqfds_lock, flags);
 
 	destroy_workqueue(irqfd_cleanup_wq);
 }
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index e34b623e4b41..4faebbb84999 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -1708,5 +1708,6 @@ static void __exit xen_pcibk_cleanup(void)
 module_init(xen_pcibk_init);
 module_exit(xen_pcibk_cleanup);
 
+MODULE_DESCRIPTION("Xen PCI-device stub driver");
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_ALIAS("xen-backend:pci");