* [PATCH net-next] net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats
@ 2018-03-18 18:23 Florian Fainelli
2018-03-18 18:54 ` Andrew Lunn
2018-03-18 20:36 ` David Miller
0 siblings, 2 replies; 3+ messages in thread
From: Florian Fainelli @ 2018-03-18 18:23 UTC (permalink / raw)
To: netdev; +Cc: Florian Fainelli, Andrew Lunn, Vivien Didelot, open list
We can hit the register lock not held assertion with the following path:
[ 34.170631] mv88e6085 0.1:00: Switch registers lock not held!
[ 34.176510] CPU: 0 PID: 950 Comm: ethtool Not tainted 4.16.0-rc4 #143
[ 34.182985] Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
[ 34.189519] Backtrace:
[ 34.192033] [<8010c4b4>] (dump_backtrace) from [<8010c788>] (show_stack+0x20/0x24)
[ 34.199680] r6:9f5dc010 r5:00000011 r4:9f5dc010 r3:00000000
[ 34.205434] [<8010c768>] (show_stack) from [<80679d38>] (dump_stack+0x24/0x28)
[ 34.212719] [<80679d14>] (dump_stack) from [<804844a8>] (mv88e6xxx_read+0x70/0x7c)
[ 34.220376] [<80484438>] (mv88e6xxx_read) from [<804870dc>] (mv88e6xxx_port_get_cmode+0x34/0x4c)
[ 34.229257] r5:a09cd128 r4:9ee31d07
[ 34.232880] [<804870a8>] (mv88e6xxx_port_get_cmode) from [<80487e6c>] (mv88e6352_port_has_serdes+0x24/0x64)
[ 34.242690] r4:9f5dc010
[ 34.245309] [<80487e48>] (mv88e6352_port_has_serdes) from [<804880b8>] (mv88e6352_serdes_get_stats+0x28/0x12c)
[ 34.255389] r4:00000001
[ 34.257973] [<80488090>] (mv88e6352_serdes_get_stats) from [<804811e8>] (mv88e6xxx_get_ethtool_stats+0xb0/0xc0)
[ 34.268156] r10:00000000 r9:00000000 r8:00000000 r7:a09cd020 r6:00000001 r5:9f5dc01c
[ 34.276052] r4:9f5dc010
[ 34.278631] [<80481138>] (mv88e6xxx_get_ethtool_stats) from [<8064f740>] (dsa_slave_get_ethtool_stats+0xbc/0xc4)
mv88e6xxx_get_ethtool_stats() calls mv88e6xxx_get_stats() which calls both
chip->info->ops->stats_get_stats(), which holds the register lock, and
chip->info->ops->serdes_get_stats() which does not. Have
chip->info->ops->serdes_get_stats() be running with the register lock held to
avoid such assertions.
Fixes: 436fe17d273b ("net: dsa: mv88e6xxx: Allow the SERDES interfaces to have statistics")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/net/dsa/mv88e6xxx/chip.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index bd3ee84770c7..c22c18ed2de3 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -849,7 +849,9 @@ static void mv88e6xxx_get_stats(struct mv88e6xxx_chip *chip, int port,
if (chip->info->ops->serdes_get_stats) {
data += count;
+ mutex_lock(&chip->reg_lock);
chip->info->ops->serdes_get_stats(chip, port, data);
+ mutex_unlock(&chip->reg_lock);
}
}
--
2.14.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats
2018-03-18 18:23 [PATCH net-next] net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats Florian Fainelli
@ 2018-03-18 18:54 ` Andrew Lunn
2018-03-18 20:36 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: Andrew Lunn @ 2018-03-18 18:54 UTC (permalink / raw)
To: Florian Fainelli; +Cc: netdev, Vivien Didelot, open list
On Sun, Mar 18, 2018 at 11:23:05AM -0700, Florian Fainelli wrote:
> We can hit the register lock not held assertion with the following path:
>
> [ 34.170631] mv88e6085 0.1:00: Switch registers lock not held!
> [ 34.176510] CPU: 0 PID: 950 Comm: ethtool Not tainted 4.16.0-rc4 #143
> [ 34.182985] Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
> [ 34.189519] Backtrace:
> [ 34.192033] [<8010c4b4>] (dump_backtrace) from [<8010c788>] (show_stack+0x20/0x24)
> [ 34.199680] r6:9f5dc010 r5:00000011 r4:9f5dc010 r3:00000000
> [ 34.205434] [<8010c768>] (show_stack) from [<80679d38>] (dump_stack+0x24/0x28)
> [ 34.212719] [<80679d14>] (dump_stack) from [<804844a8>] (mv88e6xxx_read+0x70/0x7c)
> [ 34.220376] [<80484438>] (mv88e6xxx_read) from [<804870dc>] (mv88e6xxx_port_get_cmode+0x34/0x4c)
> [ 34.229257] r5:a09cd128 r4:9ee31d07
> [ 34.232880] [<804870a8>] (mv88e6xxx_port_get_cmode) from [<80487e6c>] (mv88e6352_port_has_serdes+0x24/0x64)
> [ 34.242690] r4:9f5dc010
> [ 34.245309] [<80487e48>] (mv88e6352_port_has_serdes) from [<804880b8>] (mv88e6352_serdes_get_stats+0x28/0x12c)
> [ 34.255389] r4:00000001
> [ 34.257973] [<80488090>] (mv88e6352_serdes_get_stats) from [<804811e8>] (mv88e6xxx_get_ethtool_stats+0xb0/0xc0)
> [ 34.268156] r10:00000000 r9:00000000 r8:00000000 r7:a09cd020 r6:00000001 r5:9f5dc01c
> [ 34.276052] r4:9f5dc010
> [ 34.278631] [<80481138>] (mv88e6xxx_get_ethtool_stats) from [<8064f740>] (dsa_slave_get_ethtool_stats+0xbc/0xc4)
>
> mv88e6xxx_get_ethtool_stats() calls mv88e6xxx_get_stats() which calls both
> chip->info->ops->stats_get_stats(), which holds the register lock, and
> chip->info->ops->serdes_get_stats() which does not. Have
> chip->info->ops->serdes_get_stats() be running with the register lock held to
> avoid such assertions.
>
> Fixes: 436fe17d273b ("net: dsa: mv88e6xxx: Allow the SERDES interfaces to have statistics")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Yes, i have the same patch in my backlog of patches.
Andrew
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats
2018-03-18 18:23 [PATCH net-next] net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats Florian Fainelli
2018-03-18 18:54 ` Andrew Lunn
@ 2018-03-18 20:36 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2018-03-18 20:36 UTC (permalink / raw)
To: f.fainelli; +Cc: netdev, andrew, vivien.didelot, linux-kernel
From: Florian Fainelli <f.fainelli@gmail.com>
Date: Sun, 18 Mar 2018 11:23:05 -0700
> We can hit the register lock not held assertion with the following path:
...
> mv88e6xxx_get_ethtool_stats() calls mv88e6xxx_get_stats() which calls both
> chip->info->ops->stats_get_stats(), which holds the register lock, and
> chip->info->ops->serdes_get_stats() which does not. Have
> chip->info->ops->serdes_get_stats() be running with the register lock held to
> avoid such assertions.
>
> Fixes: 436fe17d273b ("net: dsa: mv88e6xxx: Allow the SERDES interfaces to have statistics")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Applied, thanks Florian.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-03-18 18:23 [PATCH net-next] net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats Florian Fainelli
2018-03-18 18:54 ` Andrew Lunn
2018-03-18 20:36 ` David Miller
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