There are sleep in atomic context bugs when uploading device dump
data in mwifiex. The root cause is that dev_coredumpv could not
be used in atomic contexts, because it calls dev_set_name which
include operations that may sleep. The call tree shows execution
paths that could lead to bugs:
(Interrupt context)
fw_dump_timer_fn
mwifiex_upload_device_dump
dev_coredumpv(..., GFP_KERNEL)
dev_coredumpm()
kzalloc(sizeof(*devcd), gfp); //may sleep
dev_set_name
kobject_set_name_vargs
kvasprintf_const(GFP_KERNEL, ...); //may sleep
kstrdup(s, GFP_KERNEL); //may sleep
The corresponding fail log is shown below:
[ 135.275938] usb 1-1: == mwifiex dump information to /sys/class/devcoredump start
[ 135.281029] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265
...
[ 135.293613] Call Trace:
[ 135.293613] <IRQ>
[ 135.293613] dump_stack_lvl+0x57/0x7d
[ 135.293613] __might_resched.cold+0x138/0x173
[ 135.293613] ? dev_coredumpm+0xca/0x2e0
[ 135.293613] kmem_cache_alloc_trace+0x189/0x1f0
[ 135.293613] ? devcd_match_failing+0x30/0x30
[ 135.293613] dev_coredumpm+0xca/0x2e0
[ 135.293613] ? devcd_freev+0x10/0x10
[ 135.293613] dev_coredumpv+0x1c/0x20
[ 135.293613] ? devcd_match_failing+0x30/0x30
[ 135.293613] mwifiex_upload_device_dump+0x65/0xb0
[ 135.293613] ? mwifiex_dnld_fw+0x1b0/0x1b0
[ 135.293613] call_timer_fn+0x122/0x3d0
[ 135.293613] ? msleep_interruptible+0xb0/0xb0
[ 135.293613] ? lock_downgrade+0x3c0/0x3c0
[ 135.293613] ? __next_timer_interrupt+0x13c/0x160
[ 135.293613] ? lockdep_hardirqs_on_prepare+0xe/0x220
[ 135.293613] ? mwifiex_dnld_fw+0x1b0/0x1b0
[ 135.293613] __run_timers.part.0+0x3f8/0x540
[ 135.293613] ? call_timer_fn+0x3d0/0x3d0
[ 135.293613] ? arch_restore_msi_irqs+0x10/0x10
[ 135.293613] ? lapic_next_event+0x31/0x40
[ 135.293613] run_timer_softirq+0x4f/0xb0
[ 135.293613] __do_softirq+0x1c2/0x651
...
[ 135.293613] RIP: 0010:default_idle+0xb/0x10
[ 135.293613] RSP: 0018:ffff888006317e68 EFLAGS: 00000246
[ 135.293613] RAX: ffffffff82ad8d10 RBX: ffff888006301cc0 RCX: ffffffff82ac90e1
[ 135.293613] RDX: ffffed100d9ff1b4 RSI: ffffffff831ad140 RDI: ffffffff82ad8f20
[ 135.293613] RBP: 0000000000000003 R08: 0000000000000000 R09: ffff88806cff8d9b
[ 135.293613] R10: ffffed100d9ff1b3 R11: 0000000000000001 R12: ffffffff84593410
[ 135.293613] R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff11000c62fd2
...
[ 135.389205] usb 1-1: == mwifiex dump information to /sys/class/devcoredump end
This patch uses delayed work to replace timer and moves the operations
that may sleep into a delayed work in order to mitigate bugs, it was
tested on Marvell 88W8801 chip whose port is usb and the firmware is
usb8801_uapsta.bin. The following is the result after using delayed
work to replace timer.
[ 134.936453] usb 1-1: == mwifiex dump information to /sys/class/devcoredump start
[ 135.043344] usb 1-1: == mwifiex dump information to /sys/class/devcoredump end
As we can see, there is no bug now.
Fixes: f5ecd02a8b20 ("mwifiex: device dump support for usb interface")
Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
---
Changes in v5:
- Use delayed work to replace timer.
drivers/net/wireless/marvell/mwifiex/init.c | 10 ++++++----
drivers/net/wireless/marvell/mwifiex/main.h | 2 +-
drivers/net/wireless/marvell/mwifiex/sta_event.c | 6 +++---
3 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/init.c b/drivers/net/wireless/marvell/mwifiex/init.c
index 88c72d1827a..3713f3e323f 100644
--- a/drivers/net/wireless/marvell/mwifiex/init.c
+++ b/drivers/net/wireless/marvell/mwifiex/init.c
@@ -63,9 +63,11 @@ static void wakeup_timer_fn(struct timer_list *t)
adapter->if_ops.card_reset(adapter);
}
-static void fw_dump_timer_fn(struct timer_list *t)
+static void fw_dump_work(struct work_struct *work)
{
- struct mwifiex_adapter *adapter = from_timer(adapter, t, devdump_timer);
+ struct mwifiex_adapter *adapter = container_of(work,
+ struct mwifiex_adapter,
+ devdump_work.work);
mwifiex_upload_device_dump(adapter);
}
@@ -321,7 +323,7 @@ static void mwifiex_init_adapter(struct mwifiex_adapter *adapter)
adapter->active_scan_triggered = false;
timer_setup(&adapter->wakeup_timer, wakeup_timer_fn, 0);
adapter->devdump_len = 0;
- timer_setup(&adapter->devdump_timer, fw_dump_timer_fn, 0);
+ INIT_DELAYED_WORK(&adapter->devdump_work, fw_dump_work);
}
/*
@@ -400,7 +402,7 @@ static void
mwifiex_adapter_cleanup(struct mwifiex_adapter *adapter)
{
del_timer(&adapter->wakeup_timer);
- del_timer_sync(&adapter->devdump_timer);
+ cancel_delayed_work_sync(&adapter->devdump_work);
mwifiex_cancel_all_pending_cmd(adapter);
wake_up_interruptible(&adapter->cmd_wait_q.wait);
wake_up_interruptible(&adapter->hs_activate_wait_q);
diff --git a/drivers/net/wireless/marvell/mwifiex/main.h b/drivers/net/wireless/marvell/mwifiex/main.h
index 332dd1c8db3..6530c6ee308 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.h
+++ b/drivers/net/wireless/marvell/mwifiex/main.h
@@ -1055,7 +1055,7 @@ struct mwifiex_adapter {
/* Device dump data/length */
void *devdump_data;
int devdump_len;
- struct timer_list devdump_timer;
+ struct delayed_work devdump_work;
bool ignore_btcoex_events;
};
diff --git a/drivers/net/wireless/marvell/mwifiex/sta_event.c b/drivers/net/wireless/marvell/mwifiex/sta_event.c
index 7d42c5d2dbf..4d93386494c 100644
--- a/drivers/net/wireless/marvell/mwifiex/sta_event.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_event.c
@@ -623,8 +623,8 @@ mwifiex_fw_dump_info_event(struct mwifiex_private *priv,
* transmission event get lost, in this cornel case,
* user would still get partial of the dump.
*/
- mod_timer(&adapter->devdump_timer,
- jiffies + msecs_to_jiffies(MWIFIEX_TIMER_10S));
+ schedule_delayed_work(&adapter->devdump_work,
+ msecs_to_jiffies(MWIFIEX_TIMER_10S));
}
/* Overflow check */
@@ -643,7 +643,7 @@ mwifiex_fw_dump_info_event(struct mwifiex_private *priv,
return;
upload_dump:
- del_timer_sync(&adapter->devdump_timer);
+ cancel_delayed_work_sync(&adapter->devdump_work);
mwifiex_upload_device_dump(adapter);
}
--
2.17.1
