diff options
| author | Vladimir Oltean <olteanv@gmail.com> | 2019-10-01 21:58:19 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-10-02 19:19:53 +0300 |
| commit | 3e8db7e56082156a37b71d7334860c10fcea8025 (patch) | |
| tree | 4df7d4391813771487132a4d01471064dbda15ce /net | |
| parent | d6530e5ad45089c018c3cc5b5957a34721249f6f (diff) | |
| download | linux-3e8db7e56082156a37b71d7334860c10fcea8025.tar.xz | |
net: dsa: sja1105: Fix sleeping while atomic in .port_hwtstamp_set
Currently this stack trace can be seen with CONFIG_DEBUG_ATOMIC_SLEEP=y:
[ 41.568348] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:909
[ 41.576757] in_atomic(): 1, irqs_disabled(): 0, pid: 208, name: ptp4l
[ 41.583212] INFO: lockdep is turned off.
[ 41.587123] CPU: 1 PID: 208 Comm: ptp4l Not tainted 5.3.0-rc6-01445-ge950f2d4bc7f-dirty #1827
[ 41.599873] [<c0313d7c>] (unwind_backtrace) from [<c030e13c>] (show_stack+0x10/0x14)
[ 41.607584] [<c030e13c>] (show_stack) from [<c1212d50>] (dump_stack+0xd4/0x100)
[ 41.614863] [<c1212d50>] (dump_stack) from [<c037dfc8>] (___might_sleep+0x1c8/0x2b4)
[ 41.622574] [<c037dfc8>] (___might_sleep) from [<c122ea90>] (__mutex_lock+0x48/0xab8)
[ 41.630368] [<c122ea90>] (__mutex_lock) from [<c122f51c>] (mutex_lock_nested+0x1c/0x24)
[ 41.638340] [<c122f51c>] (mutex_lock_nested) from [<c0c6fe08>] (sja1105_static_config_reload+0x30/0x27c)
[ 41.647779] [<c0c6fe08>] (sja1105_static_config_reload) from [<c0c7015c>] (sja1105_hwtstamp_set+0x108/0x1cc)
[ 41.657562] [<c0c7015c>] (sja1105_hwtstamp_set) from [<c0feb650>] (dev_ifsioc+0x18c/0x330)
[ 41.665788] [<c0feb650>] (dev_ifsioc) from [<c0febbd8>] (dev_ioctl+0x320/0x6e8)
[ 41.673064] [<c0febbd8>] (dev_ioctl) from [<c0f8b1f4>] (sock_ioctl+0x334/0x5e8)
[ 41.680340] [<c0f8b1f4>] (sock_ioctl) from [<c05404a8>] (do_vfs_ioctl+0xb0/0xa10)
[ 41.687789] [<c05404a8>] (do_vfs_ioctl) from [<c0540e3c>] (ksys_ioctl+0x34/0x58)
[ 41.695151] [<c0540e3c>] (ksys_ioctl) from [<c0301000>] (ret_fast_syscall+0x0/0x28)
[ 41.702768] Exception stack(0xe8495fa8 to 0xe8495ff0)
[ 41.707796] 5fa0: beff4a8c 00000001 00000011 000089b0 beff4a8c beff4a80
[ 41.715933] 5fc0: beff4a8c 00000001 0000000c 00000036 b6fa98c8 004e19c1 00000001 00000000
[ 41.724069] 5fe0: 004dcedc beff4a6c 004c0738 b6e7af4c
[ 41.729860] BUG: scheduling while atomic: ptp4l/208/0x00000002
[ 41.735682] INFO: lockdep is turned off.
Enabling RX timestamping will logically disturb the fastpath (processing
of meta frames). Replace bool hwts_rx_en with a bit that is checked
atomically from the fastpath and temporarily unset from the sleepable
context during a change of the RX timestamping process (a destructive
operation anyways, requires switch reset).
If found unset, the fastpath (net/dsa/tag_sja1105.c) will just drop any
received meta frame and not take the meta_lock at all.
Fixes: a602afd200f5 ("net: dsa: sja1105: Expose PTP timestamping ioctls to userspace")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/dsa/tag_sja1105.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c index 9c9aff3e52cf..63ef2a14c934 100644 --- a/net/dsa/tag_sja1105.c +++ b/net/dsa/tag_sja1105.c @@ -156,7 +156,11 @@ static struct sk_buff /* Step 1: A timestampable frame was received. * Buffer it until we get its meta frame. */ - if (is_link_local && sp->data->hwts_rx_en) { + if (is_link_local) { + if (!test_bit(SJA1105_HWTS_RX_EN, &sp->data->state)) + /* Do normal processing. */ + return skb; + spin_lock(&sp->data->meta_lock); /* Was this a link-local frame instead of the meta * that we were expecting? @@ -187,6 +191,12 @@ static struct sk_buff } else if (is_meta) { struct sk_buff *stampable_skb; + /* Drop the meta frame if we're not in the right state + * to process it. + */ + if (!test_bit(SJA1105_HWTS_RX_EN, &sp->data->state)) + return NULL; + spin_lock(&sp->data->meta_lock); stampable_skb = sp->data->stampable_skb; |