From: Johannes Berg johannes.berg@intel.com
[ Upstream commit 96178631c3f53398044ed437010f7632ad764bf8 ]
Since this is deep in the architecture, and the code is called nested into other deep management code, this really needs to be a raw spinlock. Convert it.
Link: https://patch.msgid.link/20250110125550.32479-8-johannes@sipsolutions.net Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- arch/um/kernel/irq.c | 79 ++++++++++++++++++++++++++------------------ 1 file changed, 47 insertions(+), 32 deletions(-)
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c index 338450741aac5..a4991746f5eac 100644 --- a/arch/um/kernel/irq.c +++ b/arch/um/kernel/irq.c @@ -52,7 +52,7 @@ struct irq_entry { bool sigio_workaround; };
-static DEFINE_SPINLOCK(irq_lock); +static DEFINE_RAW_SPINLOCK(irq_lock); static LIST_HEAD(active_fds); static DECLARE_BITMAP(irqs_allocated, UM_LAST_SIGNAL_IRQ); static bool irqs_suspended; @@ -257,7 +257,7 @@ static struct irq_entry *get_irq_entry_by_fd(int fd) return NULL; }
-static void free_irq_entry(struct irq_entry *to_free, bool remove) +static void remove_irq_entry(struct irq_entry *to_free, bool remove) { if (!to_free) return; @@ -265,7 +265,6 @@ static void free_irq_entry(struct irq_entry *to_free, bool remove) if (remove) os_del_epoll_fd(to_free->fd); list_del(&to_free->list); - kfree(to_free); }
static bool update_irq_entry(struct irq_entry *entry) @@ -286,17 +285,19 @@ static bool update_irq_entry(struct irq_entry *entry) return false; }
-static void update_or_free_irq_entry(struct irq_entry *entry) +static struct irq_entry *update_or_remove_irq_entry(struct irq_entry *entry) { - if (!update_irq_entry(entry)) - free_irq_entry(entry, false); + if (update_irq_entry(entry)) + return NULL; + remove_irq_entry(entry, false); + return entry; }
static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id, void (*timetravel_handler)(int, int, void *, struct time_travel_event *)) { - struct irq_entry *irq_entry; + struct irq_entry *irq_entry, *to_free = NULL; int err, events = os_event_mask(type); unsigned long flags;
@@ -304,9 +305,10 @@ static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id, if (err < 0) goto out;
- spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); irq_entry = get_irq_entry_by_fd(fd); if (irq_entry) { +already: /* cannot register the same FD twice with the same type */ if (WARN_ON(irq_entry->reg[type].events)) { err = -EALREADY; @@ -316,11 +318,22 @@ static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id, /* temporarily disable to avoid IRQ-side locking */ os_del_epoll_fd(fd); } else { - irq_entry = kzalloc(sizeof(*irq_entry), GFP_ATOMIC); - if (!irq_entry) { - err = -ENOMEM; - goto out_unlock; + struct irq_entry *new; + + /* don't restore interrupts */ + raw_spin_unlock(&irq_lock); + new = kzalloc(sizeof(*irq_entry), GFP_ATOMIC); + if (!new) { + local_irq_restore(flags); + return -ENOMEM; } + raw_spin_lock(&irq_lock); + irq_entry = get_irq_entry_by_fd(fd); + if (irq_entry) { + to_free = new; + goto already; + } + irq_entry = new; irq_entry->fd = fd; list_add_tail(&irq_entry->list, &active_fds); maybe_sigio_broken(fd); @@ -339,12 +352,11 @@ static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id, #endif
WARN_ON(!update_irq_entry(irq_entry)); - spin_unlock_irqrestore(&irq_lock, flags); - - return 0; + err = 0; out_unlock: - spin_unlock_irqrestore(&irq_lock, flags); + raw_spin_unlock_irqrestore(&irq_lock, flags); out: + kfree(to_free); return err; }
@@ -358,19 +370,20 @@ void free_irq_by_fd(int fd) struct irq_entry *to_free; unsigned long flags;
- spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); to_free = get_irq_entry_by_fd(fd); - free_irq_entry(to_free, true); - spin_unlock_irqrestore(&irq_lock, flags); + remove_irq_entry(to_free, true); + raw_spin_unlock_irqrestore(&irq_lock, flags); + kfree(to_free); } EXPORT_SYMBOL(free_irq_by_fd);
static void free_irq_by_irq_and_dev(unsigned int irq, void *dev) { - struct irq_entry *entry; + struct irq_entry *entry, *to_free = NULL; unsigned long flags;
- spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); list_for_each_entry(entry, &active_fds, list) { enum um_irq_type i;
@@ -386,12 +399,13 @@ static void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
os_del_epoll_fd(entry->fd); reg->events = 0; - update_or_free_irq_entry(entry); + to_free = update_or_remove_irq_entry(entry); goto out; } } out: - spin_unlock_irqrestore(&irq_lock, flags); + raw_spin_unlock_irqrestore(&irq_lock, flags); + kfree(to_free); }
void deactivate_fd(int fd, int irqnum) @@ -402,7 +416,7 @@ void deactivate_fd(int fd, int irqnum)
os_del_epoll_fd(fd);
- spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); entry = get_irq_entry_by_fd(fd); if (!entry) goto out; @@ -414,9 +428,10 @@ void deactivate_fd(int fd, int irqnum) entry->reg[i].events = 0; }
- update_or_free_irq_entry(entry); + entry = update_or_remove_irq_entry(entry); out: - spin_unlock_irqrestore(&irq_lock, flags); + raw_spin_unlock_irqrestore(&irq_lock, flags); + kfree(entry);
ignore_sigio_fd(fd); } @@ -546,7 +561,7 @@ void um_irqs_suspend(void)
irqs_suspended = true;
- spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); list_for_each_entry(entry, &active_fds, list) { enum um_irq_type t; bool clear = true; @@ -579,7 +594,7 @@ void um_irqs_suspend(void) !__ignore_sigio_fd(entry->fd); } } - spin_unlock_irqrestore(&irq_lock, flags); + raw_spin_unlock_irqrestore(&irq_lock, flags); }
void um_irqs_resume(void) @@ -588,7 +603,7 @@ void um_irqs_resume(void) unsigned long flags;
- spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); list_for_each_entry(entry, &active_fds, list) { if (entry->suspended) { int err = os_set_fd_async(entry->fd); @@ -602,7 +617,7 @@ void um_irqs_resume(void) } } } - spin_unlock_irqrestore(&irq_lock, flags); + raw_spin_unlock_irqrestore(&irq_lock, flags);
irqs_suspended = false; send_sigio_to_self(); @@ -613,7 +628,7 @@ static int normal_irq_set_wake(struct irq_data *d, unsigned int on) struct irq_entry *entry; unsigned long flags;
- spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); list_for_each_entry(entry, &active_fds, list) { enum um_irq_type t;
@@ -628,7 +643,7 @@ static int normal_irq_set_wake(struct irq_data *d, unsigned int on) } } unlock: - spin_unlock_irqrestore(&irq_lock, flags); + raw_spin_unlock_irqrestore(&irq_lock, flags); return 0; } #else