On 11/4/20 5:29 AM, Srinivas Kandagatla wrote:
running kernel with CONFIG_DEBUG_LOCKS_ALLOC enabled will below warning:
BUG: key ffff502e09807098 has not been registered!
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 5 PID: 129 at kernel/locking/lockdep.c:4623
lockdep_init_map_waits+0xe8/0x250
Modules linked in:
CPU: 5 PID: 129 Comm: kworker/5:1 Tainted: G
W 5.10.0-rc1-00277-ged49f224ca3f-dirty #1210
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Workqueue: events deferred_probe_work_func
pstate: 80c00005 (Nzcv daif +PAN +UAO -TCO BTYPE=--)
pc : lockdep_init_map_waits+0xe8/0x250
lr : lockdep_init_map_waits+0xe8/0x250
[ Trimmed ]
Call trace:
lockdep_init_map_waits+0xe8/0x250
__kernfs_create_file+0x78/0x180
sysfs_add_file_mode_ns+0x94/0x1c8
internal_create_group+0x110/0x3e0
sysfs_create_group+0x18/0x28
devm_device_add_group+0x4c/0xb0
add_all_attributes+0x438/0x490
sdw_slave_sysfs_dpn_init+0x128/0x138
sdw_slave_sysfs_init+0x80/0xa0
sdw_drv_probe+0x94/0x170
really_probe+0x118/0x3e0
driver_probe_device+0x5c/0xc0
[ Trimmed ]
CPU: 5 PID: 129 Comm: kworker/5:1 Tainted: G
W 5.10.0-rc1-00277-ged49f224ca3f-dirty #1210
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Workqueue: events deferred_probe_work_func
Call trace:
dump_backtrace+0x0/0x1c0
show_stack+0x18/0x68
dump_stack+0xd8/0x134
__warn+0xa0/0x158
report_bug+0xc8/0x178
bug_handler+0x20/0x78
brk_handler+0x70/0xc8
[ Trimmed ]
Fix this by initializing dynamically allocated sysfs attribute to keep lockdep happy!
Fixes: bcac59029955 ("soundwire: add Slave sysfs support")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
I added the exact same fix last Friday but you beat me to it.
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
My commit message was a bit more self-explanatory though, maybe you
could add the explanation at the end and possibly trim the logs?
"
when CONFIG_DEBUG_LOCK_ALLOC is enabled, a warning is thrown, e.g.
kernel: [ 4.078863] BUG: key ffff8a9203c92dc0 has not been registered!
kernel: [ 4.078865] ------------[ cut here ]------------
kernel: [ 4.078866] DEBUG_LOCKS_WARN_ON(1)
kernel: [ 4.078871] WARNING: CPU: 0 PID: 280 at
kernel/locking/lockdep.c:4623 lockdep_init_map_waits+0x177/0x200
kernel: [ 4.078902] Call Trace:
kernel: [ 4.078906] __kernfs_create_file+0x76/0x100
kernel: [ 4.078908] sysfs_add_file_mode_ns+0x9f/0x190
kernel: [ 4.078909] internal_create_group+0x112/0x380
kernel: [ 4.078912] devm_device_add_group+0x41/0x80
kernel: [ 4.078915] add_all_attributes+0x4bf/0x4e0 [soundwire_bus]
kernel: [ 4.078918] sdw_slave_sysfs_dpn_init+0x68/0xe0 [soundwire_bus]
kernel: [ 4.078920] sdw_slave_sysfs_init+0x6b/0x80 [soundwire_bus]
For DPn ports, the attributes are allocated dynamically and it's
required to use the macro sysfs_attr_init(), whose behavior is
precisely dependent on CONFIG_DEBUG_LOCK_ALLOC. See details in
linux/sysfs.h.
"
Thanks Srinivas!
---
drivers/soundwire/sysfs_slave_dpn.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/soundwire/sysfs_slave_dpn.c b/drivers/soundwire/sysfs_slave_dpn.c
index 05a721ea9830..c4b6543c09fd 100644
--- a/drivers/soundwire/sysfs_slave_dpn.c
+++ b/drivers/soundwire/sysfs_slave_dpn.c
@@ -37,6 +37,7 @@ static int field##_attribute_alloc(struct device *dev, \
return -ENOMEM; \
dpn_attr->N = N; \
dpn_attr->dir = dir; \
+ sysfs_attr_init(&dpn_attr->dev_attr.attr); \
dpn_attr->format_string = format_string; \
dpn_attr->dev_attr.attr.name = __stringify(field); \
dpn_attr->dev_attr.attr.mode = 0444; \
