lkml.org 
[lkml]   [2022]   [Oct]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC][PATCH v2 19/31] timers: net: Use del_timer_shutdown() before freeing timer
On Fri, 28 Oct 2022 18:31:49 -0400 Steven Rostedt wrote:
> Could someone from networking confirm (or deny) that the timer being
> removed in sk_stop_timer() will no longer be used even if del_timer()
> returns false?
>
> net/core/sock.c:
>
> void sk_stop_timer(struct sock *sk, struct timer_list* timer)
> {
> if (del_timer(timer))
> __sock_put(sk);
> }
>
> If this is the case, then I'll add the following interface:
>
> del_timer_sync_shutdown() // the common case which syncs
>
> del_timer_shutdown() // the uncommon case, that returns immediately
> // used for those cases that add extra code to
> // handle it, like sk_stop_timer()

Sorry too many bugs at once :)

FWIW Paolo was saying privately earlier today that he spotted some cases
of reuse, he gave an example of ccid2_hc_tx_packet_recv()

So we can't convert all cases of sk_stop_timer() in one fell swoop :(

> Which has the same semantics as del_timer_sync() and del_timer()
> respectively, but will prevent the timer from being rearmed again.
>
> This way we can convert the sk_stop_timer() to:
>
> void sk_stop_timer(struct sock *sk, struct timer_list* timer)
> {
> if (del_timer_shutdown(timer))
> __sock_put(sk);
> }
>
>
> We can also add the del_timer_shutdown() to other locations that need to
> put a timer into a shutdown state before freeing, and where it's in a
> context that can not call del_timer_sync_shutdown().

\
 
 \ /
  Last update: 2022-10-29 00:46    [W:0.165 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site