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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
eventfd: make eventfd_signal{_mask}() void
No caller care about the return value.
Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-4-bd549b14ce0c@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
+22
-34
+15
-25
fs/eventfd.c
+15
-25
fs/eventfd.c
···
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int id;
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};
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-
__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
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/**
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* eventfd_signal_mask - Increment the event counter
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* @ctx: [in] Pointer to the eventfd context.
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* @mask: [in] poll mask
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*
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* This function is supposed to be called by the kernel in paths that do not
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* allow sleeping. In this function we allow the counter to reach the ULLONG_MAX
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* value, and we signal this as overflow condition by returning a EPOLLERR
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* to poll(2).
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*/
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void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
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{
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unsigned long flags;
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-
__u64 n = 1;
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/*
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* Deadlock or stack overflow issues can happen if we recurse here
···
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* safe context.
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*/
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if (WARN_ON_ONCE(current->in_eventfd))
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return 0;
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return;
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spin_lock_irqsave(&ctx->wqh.lock, flags);
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current->in_eventfd = 1;
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if (ULLONG_MAX - ctx->count < n)
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n = ULLONG_MAX - ctx->count;
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ctx->count += n;
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if (ctx->count < ULLONG_MAX)
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ctx->count++;
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if (waitqueue_active(&ctx->wqh))
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wake_up_locked_poll(&ctx->wqh, EPOLLIN | mask);
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current->in_eventfd = 0;
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spin_unlock_irqrestore(&ctx->wqh.lock, flags);
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-
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return n == 1;
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}
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-
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/**
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* eventfd_signal - Increment the event counter
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* @ctx: [in] Pointer to the eventfd context.
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*
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* This function is supposed to be called by the kernel in paths that do not
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* allow sleeping. In this function we allow the counter to reach the ULLONG_MAX
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* value, and we signal this as overflow condition by returning a EPOLLERR
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* to poll(2).
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*
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* Returns the amount by which the counter was incremented.
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*/
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__u64 eventfd_signal(struct eventfd_ctx *ctx)
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{
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return eventfd_signal_mask(ctx, 0);
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}
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EXPORT_SYMBOL_GPL(eventfd_signal);
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EXPORT_SYMBOL_GPL(eventfd_signal_mask);
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static void eventfd_free_ctx(struct eventfd_ctx *ctx)
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{
+7
-9
include/linux/eventfd.h
+7
-9
include/linux/eventfd.h
···
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struct file *eventfd_fget(int fd);
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struct eventfd_ctx *eventfd_ctx_fdget(int fd);
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struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
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__u64 eventfd_signal(struct eventfd_ctx *ctx);
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__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
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void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
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int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,
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__u64 *cnt);
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void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt);
···
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return ERR_PTR(-ENOSYS);
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}
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-
static inline int eventfd_signal(struct eventfd_ctx *ctx)
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static inline void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
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{
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-
return -ENOSYS;
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}
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static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
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{
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return -ENOSYS;
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}
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static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
···
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}
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#endif
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static inline void eventfd_signal(struct eventfd_ctx *ctx)
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{
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eventfd_signal_mask(ctx, 0);
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}
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#endif /* _LINUX_EVENTFD_H */
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