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Commit ee62c6b2 authored by Sha Zhengju's avatar Sha Zhengju Committed by Linus Torvalds
Browse files

eventfd: change int to __u64 in eventfd_signal() 



eventfd_ctx->count is an __u64 counter which is allowed to reach
ULLONG_MAX.  eventfd_write() adds a __u64 value to "count", but the kernel
side eventfd_signal() only adds an int value to it.  Make them consistent.

[akpm@linux-foundation.org: update interface documentation]
Signed-off-by: default avatarSha Zhengju <handai.szj@taobao.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 71ca97da

fs/eventfd.c

+4 −8
Original line number Original line Diff line number Diff line
@@ -46,20 +46,16 @@ struct eventfd_ctx { 
 * value, and we signal this as overflow condition by returining a POLLERR

 * value, and we signal this as overflow condition by returining a POLLERR

 * to poll(2).

 * to poll(2).

 *

 *

 * Returns @n in case of success, a non-negative number lower than @n in case

 * Returns the amount by which the counter was incrememnted.  This will be less

 * of overflow, or the following error codes:

 * than @n if the counter has overflowed.

 *

 * -EINVAL    : The value of @n is negative.

 */

 */

int eventfd_signal(struct eventfd_ctx *ctx, int n)

__u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n)

{

{

	unsigned long flags;

	unsigned long flags;





	if (n < 0)

		return -EINVAL;

	spin_lock_irqsave(&ctx->wqh.lock, flags);

	spin_lock_irqsave(&ctx->wqh.lock, flags);

	if (ULLONG_MAX - ctx->count < n)

	if (ULLONG_MAX - ctx->count < n)

		n = (int) (ULLONG_MAX - ctx->count);

		n = ULLONG_MAX - ctx->count;

	ctx->count += n;

	ctx->count += n;

	if (waitqueue_active(&ctx->wqh))

	if (waitqueue_active(&ctx->wqh))

		wake_up_locked_poll(&ctx->wqh, POLLIN);

		wake_up_locked_poll(&ctx->wqh, POLLIN);

include/linux/eventfd.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -34,7 +34,7 @@ void eventfd_ctx_put(struct eventfd_ctx *ctx); 
struct file *eventfd_fget(int fd);

struct file *eventfd_fget(int fd);

struct eventfd_ctx *eventfd_ctx_fdget(int fd);

struct eventfd_ctx *eventfd_ctx_fdget(int fd);

struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);

struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);

int eventfd_signal(struct eventfd_ctx *ctx, int n);

__u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n);

ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt);

ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt);

int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_t *wait,

int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_t *wait,

				  __u64 *cnt);

				  __u64 *cnt);