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Message-ID: <000201c86d53$569297e0$453c822c@dg8ngn>
Date: Tue, 12 Feb 2008 09:43:26 +0100
From: "Jann Traschewski" <jann@....de>
To: "'Jarek Poplawski'" <jarkao2@...il.com>,
"'David Miller'" <davem@...emloft.net>
Cc: "'Bernard Pidoux F6BVP'" <f6bvp@...e.fr>,
"'Ralf Baechle DL5RB'" <ralf@...ux-mips.org>,
<netdev@...r.kernel.org>
Subject: Re: [PATCH][AX25] ax25_route: make ax25_route_lock BH safe
Applied on 2.6.24.2 and up without any problems/warnings since 12 hours.
Thanks,
Jann
> -----Ursprüngliche Nachricht-----
> Von: Jarek Poplawski [mailto:jarkao2@...il.com]
> Gesendet: Montag, 11. Februar 2008 13:43
> An: David Miller
> Cc: Jann Traschewski; Bernard Pidoux F6BVP; Ralf Baechle
> DL5RB; netdev@...r.kernel.org
> Betreff: [PATCH][AX25] ax25_route: make ax25_route_lock BH safe
>
>
> Subject: [AX25] ax25_route: make ax25_route_lock BH safe
>
> > =================================
> > [ INFO: inconsistent lock state ]
> > 2.6.24-dg8ngn-p02 #1
> > ---------------------------------
> > inconsistent {softirq-on-W} -> {in-softirq-R} usage.
> > linuxnet/3046 [HC0[0]:SC1[2]:HE1:SE0] takes:
> > (ax25_route_lock){--.+}, at: [<f8a0cfb7>] ax25_get_route+0x18/0xb7
> > [ax25] {softirq-on-W} state was registered at:
> ...
>
> This lockdep report shows that ax25_route_lock is taken for
> reading in softirq context, and for writing in process
> context with BHs enabled.
> So, to make this safe, all write_locks in ax25_route.c are
> changed to _bh versions.
>
>
> Reported-by: Jann Traschewski <jann@....de>,
> Signed-off-by: Jarek Poplawski <jarkao2@...il.com>
>
> ---
>
> diff -Nurp 2.6.24-mm1-/net/ax25/ax25_route.c
> 2.6.24-mm1+/net/ax25/ax25_route.c
> --- 2.6.24-mm1-/net/ax25/ax25_route.c 2008-02-05
> 07:45:38.000000000 +0000
> +++ 2.6.24-mm1+/net/ax25/ax25_route.c 2008-02-11
> 11:58:47.000000000 +0000
> @@ -45,7 +45,7 @@ void ax25_rt_device_down(struct net_devi {
> ax25_route *s, *t, *ax25_rt;
>
> - write_lock(&ax25_route_lock);
> + write_lock_bh(&ax25_route_lock);
> ax25_rt = ax25_route_list;
> while (ax25_rt != NULL) {
> s = ax25_rt;
> @@ -68,7 +68,7 @@ void ax25_rt_device_down(struct net_devi
> }
> }
> }
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
> }
>
> static int __must_check ax25_rt_add(struct
> ax25_routes_struct *route) @@ -82,7 +82,7 @@ static int
> __must_check ax25_rt_add(stru
> if (route->digi_count > AX25_MAX_DIGIS)
> return -EINVAL;
>
> - write_lock(&ax25_route_lock);
> + write_lock_bh(&ax25_route_lock);
>
> ax25_rt = ax25_route_list;
> while (ax25_rt != NULL) {
> @@ -92,7 +92,7 @@ static int __must_check ax25_rt_add(stru
> ax25_rt->digipeat = NULL;
> if (route->digi_count != 0) {
> if ((ax25_rt->digipeat =
> kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
> - write_unlock(&ax25_route_lock);
> +
> write_unlock_bh(&ax25_route_lock);
> return -ENOMEM;
> }
> ax25_rt->digipeat->lastrepeat =
> -1; @@ -102,14 +102,14 @@ static int __must_check ax25_rt_add(stru
>
> ax25_rt->digipeat->calls[i] = route->digi_addr[i];
> }
> }
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
> return 0;
> }
> ax25_rt = ax25_rt->next;
> }
>
> if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC))
> == NULL) {
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
> return -ENOMEM;
> }
>
> @@ -120,7 +120,7 @@ static int __must_check ax25_rt_add(stru
> ax25_rt->ip_mode = ' ';
> if (route->digi_count != 0) {
> if ((ax25_rt->digipeat =
> kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
> kfree(ax25_rt);
> return -ENOMEM;
> }
> @@ -133,7 +133,7 @@ static int __must_check ax25_rt_add(stru
> }
> ax25_rt->next = ax25_route_list;
> ax25_route_list = ax25_rt;
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
>
> return 0;
> }
> @@ -152,7 +152,7 @@ static int ax25_rt_del(struct ax25_route
> if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
> return -EINVAL;
>
> - write_lock(&ax25_route_lock);
> + write_lock_bh(&ax25_route_lock);
>
> ax25_rt = ax25_route_list;
> while (ax25_rt != NULL) {
> @@ -174,7 +174,7 @@ static int ax25_rt_del(struct ax25_route
> }
> }
> }
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
>
> return 0;
> }
> @@ -188,7 +188,7 @@ static int ax25_rt_opt(struct ax25_route
> if ((ax25_dev =
> ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
> return -EINVAL;
>
> - write_lock(&ax25_route_lock);
> + write_lock_bh(&ax25_route_lock);
>
> ax25_rt = ax25_route_list;
> while (ax25_rt != NULL) {
> @@ -216,7 +216,7 @@ static int ax25_rt_opt(struct ax25_route
> }
>
> out:
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
> return err;
> }
>
> @@ -492,7 +492,7 @@ void __exit ax25_rt_free(void) {
> ax25_route *s, *ax25_rt = ax25_route_list;
>
> - write_lock(&ax25_route_lock);
> + write_lock_bh(&ax25_route_lock);
> while (ax25_rt != NULL) {
> s = ax25_rt;
> ax25_rt = ax25_rt->next;
> @@ -500,5 +500,5 @@ void __exit ax25_rt_free(void)
> kfree(s->digipeat);
> kfree(s);
> }
> - write_unlock(&ax25_route_lock);
> + write_unlock_bh(&ax25_route_lock);
> }
--
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