lkml.org 
[lkml]   [2019]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH net/tipc] Replace rcu_swap_protected() with rcu_replace_pointer()
From
Date
On 12/10/19 11:31 AM, Paul E. McKenney wrote:
> This commit replaces the use of rcu_swap_protected() with the more
> intuitively appealing rcu_replace_pointer() as a step towards removing
> rcu_swap_protected().
>
> Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=Z7-GGtM6wcvtyytXZA1+BHqta4gg6Hw@mail.gmail.com/
> Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> Cc: Jon Maloy <jon.maloy@ericsson.com>
> Cc: Ying Xue <ying.xue@windriver.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: <netdev@vger.kernel.org>
> Cc: <tipc-discussion@lists.sourceforge.net>
>
> diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
> index 990a872..64cf831 100644
> --- a/net/tipc/crypto.c
> +++ b/net/tipc/crypto.c
> @@ -258,7 +258,7 @@ static char *tipc_key_change_dump(struct tipc_key old, struct tipc_key new,
> rcu_dereference_protected((rcu_ptr), lockdep_is_held(lock))
>
> #define tipc_aead_rcu_swap(rcu_ptr, ptr, lock) \
> - rcu_swap_protected((rcu_ptr), (ptr), lockdep_is_held(lock))
> + rcu_replace_pointer((rcu_ptr), (ptr), lockdep_is_held(lock))

(ptr) = rcu_replace_pointer((rcu_ptr), (ptr), lockdep_is_held(lock))

>
> #define tipc_aead_rcu_replace(rcu_ptr, ptr, lock) \
> do { \
> @@ -1189,7 +1189,7 @@ static bool tipc_crypto_key_try_align(struct tipc_crypto *rx, u8 new_pending)
>
> /* Move passive key if any */
> if (key.passive) {
> - tipc_aead_rcu_swap(rx->aead[key.passive], tmp2, &rx->lock);
> + tmp2 = rcu_replace_pointer(rx->aead[key.passive], tmp2, &rx->lock);

tipc_aead_rcu_swap() is only called here in TIPC module. If we use
rcu_replace_pointer() to switch pointers instead of calling
tipc_aead_rcu_swap() macro, I think we should completely remove
tipc_aead_rcu_swap().

> x = (key.passive - key.pending + new_pending) % KEY_MAX;
> new_passive = (x <= 0) ? x + KEY_MAX : x;
> }
>

\
 
 \ /
  Last update: 2019-12-10 17:00    [W:0.037 / U:15.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site