From e3306dd5f7eb2e699f36a4a313fca4b48b18d5e1 Mon Sep 17 00:00:00 2001 From: Davide Libenzi Date: Tue, 27 Sep 2005 21:45:33 -0700 Subject: [PATCH] [PATCH] epoll: handle timeout overflow Handle the timeout upper boundary for epoll. Signed-off-by: Davide Libenzi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/eventpoll.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 403b90a..4284cd3 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -101,6 +101,10 @@ /* Maximum number of poll wake up nests we are allowing */ #define EP_MAX_POLLWAKE_NESTS 4 +/* Maximum msec timeout value storeable in a long int */ +#define EP_MAX_MSTIMEO min(1000ULL * MAX_SCHEDULE_TIMEOUT / HZ, (LONG_MAX - 999ULL) / HZ) + + struct epoll_filefd { struct file *file; int fd; @@ -1506,8 +1510,8 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events, * and the overflow condition. The passed timeout is in milliseconds, * that why (t * HZ) / 1000. */ - jtimeout = timeout == -1 || timeout > (MAX_SCHEDULE_TIMEOUT - 1000) / HZ ? - MAX_SCHEDULE_TIMEOUT: (timeout * HZ + 999) / 1000; + jtimeout = (timeout < 0 || timeout >= EP_MAX_MSTIMEO) ? + MAX_SCHEDULE_TIMEOUT : (timeout * HZ + 999) / 1000; retry: write_lock_irqsave(&ep->lock, flags); -- 2.7.4