[PATCH v2 4/4] eventfd: make eventfd_signal{_mask}() void

Christian Brauner
2023-11-22T12:50:08Z

No caller care about the return value.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/eventfd.c | 40 +++++++++++++++-------------------------
include/linux/eventfd.h | 16 +++++++---------
2 files changed, 22 insertions(+), 34 deletions(-)

diff --git a/fs/eventfd.c b/fs/eventfd.c
index a9a6de920fb4..13be2fb7fc96 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -43,10 +43,19 @@ struct eventfd_ctx {
int id;
};

-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
+/**
+ * eventfd_signal - Adds @n to the eventfd counter.
+ * @ctx: [in] Pointer to the eventfd context.
+ * @mask: [in] poll mask
+ *
+ * This function is supposed to be called by the kernel in paths that do not
+ * allow sleeping. In this function we allow the counter to reach the ULLONG_MAX
+ * value, and we signal this as overflow condition by returning a EPOLLERR
+ * to poll(2).
+ */
+void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
{
unsigned long flags;
- __u64 n = 1;

/*
* Deadlock or stack overflow issues can happen if we recurse here
@@ -57,37 +66,18 @@ __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
* safe context.
*/
if (WARN_ON_ONCE(current->in_eventfd))
- return 0;
+ return;

spin_lock_irqsave(&ctx->wqh.lock, flags);
current->in_eventfd = 1;
- if (ULLONG_MAX - ctx->count < n)
- n = ULLONG_MAX - ctx->count;
- ctx->count += n;
+ if (ctx->count < ULLONG_MAX)
+ ctx->count++;
if (waitqueue_active(&ctx->wqh))
wake_up_locked_poll(&ctx->wqh, EPOLLIN | mask);
current->in_eventfd = 0;
spin_unlock_irqrestore(&ctx->wqh.lock, flags);
-
- return n == 1;
-}
-
-/**
- * eventfd_signal - Adds @n to the eventfd counter.
- * @ctx: [in] Pointer to the eventfd context.
- *
- * This function is supposed to be called by the kernel in paths that do not
- * allow sleeping. In this function we allow the counter to reach the ULLONG_MAX
- * value, and we signal this as overflow condition by returning a EPOLLERR
- * to poll(2).
- *
- * Returns the amount by which the counter was incremented.
- */
-__u64 eventfd_signal(struct eventfd_ctx *ctx)
-{
- return eventfd_signal_mask(ctx, 0);
}
-EXPORT_SYMBOL_GPL(eventfd_signal);
+EXPORT_SYMBOL_GPL(eventfd_signal_mask);

static void eventfd_free_ctx(struct eventfd_ctx *ctx)
{
diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
index 4f8aac7eb62a..fea7c4eb01d6 100644
--- a/include/linux/eventfd.h
+++ b/include/linux/eventfd.h
@@ -35,8 +35,7 @@ void eventfd_ctx_put(struct eventfd_ctx *ctx);
struct file *eventfd_fget(int fd);
struct eventfd_ctx *eventfd_ctx_fdget(int fd);
struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
-__u64 eventfd_signal(struct eventfd_ctx *ctx);
-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
+void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,
__u64 *cnt);
void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt);
@@ -58,14 +57,8 @@ static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
return ERR_PTR(-ENOSYS);
}

-static inline int eventfd_signal(struct eventfd_ctx *ctx)
+static inline void eventfd_signal_mask(struct eventfd_ctx *ctx, unsigned mask)
{
- return -ENOSYS;
-}
-
-static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, unsigned mask)
-{
- return -ENOSYS;
}

static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
@@ -91,5 +84,10 @@ static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt)

#endif

+static inline void eventfd_signal(struct eventfd_ctx *ctx)
+{
+ eventfd_signal_mask(ctx, 0);
+}
+
#endif /* _LINUX_EVENTFD_H */

--
2.42.0