mirror of
https://git.yoctoproject.org/meta-ti
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Koen Kooi
df83a59b6b
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net> Signed-off-by: Denys Dmytriyenko <denys@ti.com>
116 lines
4.6 KiB
Diff
116 lines
4.6 KiB
Diff
From f525976c33830cfe23b1a73eb9ae853820c5c085 Mon Sep 17 00:00:00 2001
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From: Neil Horman <nhorman@tuxdriver.com>
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Date: Fri, 27 Apr 2012 10:11:48 +0000
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Subject: [PATCH 63/70] drop_monitor: fix sleeping in invalid context warning
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commit cde2e9a651b76d8db36ae94cd0febc82b637e5dd upstream.
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Eric Dumazet pointed out this warning in the drop_monitor protocol to me:
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[ 38.352571] BUG: sleeping function called from invalid context at kernel/mutex.c:85
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[ 38.352576] in_atomic(): 1, irqs_disabled(): 0, pid: 4415, name: dropwatch
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[ 38.352580] Pid: 4415, comm: dropwatch Not tainted 3.4.0-rc2+ #71
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[ 38.352582] Call Trace:
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[ 38.352592] [<ffffffff8153aaf0>] ? trace_napi_poll_hit+0xd0/0xd0
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[ 38.352599] [<ffffffff81063f2a>] __might_sleep+0xca/0xf0
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[ 38.352606] [<ffffffff81655b16>] mutex_lock+0x26/0x50
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[ 38.352610] [<ffffffff8153aaf0>] ? trace_napi_poll_hit+0xd0/0xd0
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[ 38.352616] [<ffffffff810b72d9>] tracepoint_probe_register+0x29/0x90
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[ 38.352621] [<ffffffff8153a585>] set_all_monitor_traces+0x105/0x170
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[ 38.352625] [<ffffffff8153a8ca>] net_dm_cmd_trace+0x2a/0x40
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[ 38.352630] [<ffffffff8154a81a>] genl_rcv_msg+0x21a/0x2b0
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[ 38.352636] [<ffffffff810f8029>] ? zone_statistics+0x99/0xc0
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[ 38.352640] [<ffffffff8154a600>] ? genl_rcv+0x30/0x30
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[ 38.352645] [<ffffffff8154a059>] netlink_rcv_skb+0xa9/0xd0
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[ 38.352649] [<ffffffff8154a5f0>] genl_rcv+0x20/0x30
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[ 38.352653] [<ffffffff81549a7e>] netlink_unicast+0x1ae/0x1f0
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[ 38.352658] [<ffffffff81549d76>] netlink_sendmsg+0x2b6/0x310
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[ 38.352663] [<ffffffff8150824f>] sock_sendmsg+0x10f/0x130
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[ 38.352668] [<ffffffff8150abe0>] ? move_addr_to_kernel+0x60/0xb0
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[ 38.352673] [<ffffffff81515f04>] ? verify_iovec+0x64/0xe0
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[ 38.352677] [<ffffffff81509c46>] __sys_sendmsg+0x386/0x390
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[ 38.352682] [<ffffffff810ffaf9>] ? handle_mm_fault+0x139/0x210
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[ 38.352687] [<ffffffff8165b5bc>] ? do_page_fault+0x1ec/0x4f0
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[ 38.352693] [<ffffffff8106ba4d>] ? set_next_entity+0x9d/0xb0
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[ 38.352699] [<ffffffff81310b49>] ? tty_ldisc_deref+0x9/0x10
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[ 38.352703] [<ffffffff8106d363>] ? pick_next_task_fair+0x63/0x140
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[ 38.352708] [<ffffffff8150b8d4>] sys_sendmsg+0x44/0x80
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[ 38.352713] [<ffffffff8165f8e2>] system_call_fastpath+0x16/0x1b
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It stems from holding a spinlock (trace_state_lock) while attempting to register
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or unregister tracepoint hooks, making in_atomic() true in this context, leading
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to the warning when the tracepoint calls might_sleep() while its taking a mutex.
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Since we only use the trace_state_lock to prevent trace protocol state races, as
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well as hardware stat list updates on an rcu write side, we can just convert the
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spinlock to a mutex to avoid this problem.
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Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
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Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
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CC: David Miller <davem@davemloft.net>
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Acked-by: Eric Dumazet <edumazet@google.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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---
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net/core/drop_monitor.c | 14 +++++++-------
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1 files changed, 7 insertions(+), 7 deletions(-)
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diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
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index 7f36b38..f74d7d7 100644
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--- a/net/core/drop_monitor.c
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+++ b/net/core/drop_monitor.c
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@@ -42,7 +42,7 @@ static void send_dm_alert(struct work_struct *unused);
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* netlink alerts
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*/
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static int trace_state = TRACE_OFF;
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-static DEFINE_SPINLOCK(trace_state_lock);
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+static DEFINE_MUTEX(trace_state_mutex);
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struct per_cpu_dm_data {
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struct work_struct dm_alert_work;
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@@ -213,7 +213,7 @@ static int set_all_monitor_traces(int state)
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struct dm_hw_stat_delta *new_stat = NULL;
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struct dm_hw_stat_delta *temp;
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- spin_lock(&trace_state_lock);
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+ mutex_lock(&trace_state_mutex);
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if (state == trace_state) {
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rc = -EAGAIN;
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@@ -252,7 +252,7 @@ static int set_all_monitor_traces(int state)
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rc = -EINPROGRESS;
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out_unlock:
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- spin_unlock(&trace_state_lock);
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+ mutex_unlock(&trace_state_mutex);
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return rc;
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}
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@@ -295,12 +295,12 @@ static int dropmon_net_event(struct notifier_block *ev_block,
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new_stat->dev = dev;
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new_stat->last_rx = jiffies;
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- spin_lock(&trace_state_lock);
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+ mutex_lock(&trace_state_mutex);
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list_add_rcu(&new_stat->list, &hw_stats_list);
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- spin_unlock(&trace_state_lock);
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+ mutex_unlock(&trace_state_mutex);
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break;
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case NETDEV_UNREGISTER:
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- spin_lock(&trace_state_lock);
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+ mutex_lock(&trace_state_mutex);
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list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
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if (new_stat->dev == dev) {
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new_stat->dev = NULL;
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@@ -311,7 +311,7 @@ static int dropmon_net_event(struct notifier_block *ev_block,
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}
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}
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}
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- spin_unlock(&trace_state_lock);
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+ mutex_unlock(&trace_state_mutex);
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break;
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}
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out:
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--
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1.7.7.6
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