| From 80624263fa289b3416f7ca309491f1b75e579477 Mon Sep 17 00:00:00 2001 |
| From: Suzuki K Poulose <suzuki.poulose@arm.com> |
| Date: Thu, 29 Oct 2020 10:45:58 -0600 |
| Subject: coresight: cti: Initialize dynamic sysfs attributes |
| |
| From: Suzuki K Poulose <suzuki.poulose@arm.com> |
| |
| commit 80624263fa289b3416f7ca309491f1b75e579477 upstream. |
| |
| With LOCKDEP enabled, CTI driver triggers the following splat due |
| to uninitialized lock class for dynamically allocated attribute |
| objects. |
| |
| [ 5.372901] coresight etm0: CPU0: ETM v4.0 initialized |
| [ 5.376694] coresight etm1: CPU1: ETM v4.0 initialized |
| [ 5.380785] coresight etm2: CPU2: ETM v4.0 initialized |
| [ 5.385851] coresight etm3: CPU3: ETM v4.0 initialized |
| [ 5.389808] BUG: key ffff00000564a798 has not been registered! |
| [ 5.392456] ------------[ cut here ]------------ |
| [ 5.398195] DEBUG_LOCKS_WARN_ON(1) |
| [ 5.398233] WARNING: CPU: 1 PID: 32 at kernel/locking/lockdep.c:4623 lockdep_init_map_waits+0x14c/0x260 |
| [ 5.406149] Modules linked in: |
| [ 5.415411] CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.9.0-12034-gbbe85027ce80 #51 |
| [ 5.418553] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) |
| [ 5.426453] Workqueue: events amba_deferred_retry_func |
| [ 5.433299] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--) |
| [ 5.438252] pc : lockdep_init_map_waits+0x14c/0x260 |
| [ 5.444410] lr : lockdep_init_map_waits+0x14c/0x260 |
| [ 5.449007] sp : ffff800012bbb720 |
| ... |
| |
| [ 5.531561] Call trace: |
| [ 5.536847] lockdep_init_map_waits+0x14c/0x260 |
| [ 5.539027] __kernfs_create_file+0xa8/0x1c8 |
| [ 5.543539] sysfs_add_file_mode_ns+0xd0/0x208 |
| [ 5.548054] internal_create_group+0x118/0x3c8 |
| [ 5.552307] internal_create_groups+0x58/0xb8 |
| [ 5.556733] sysfs_create_groups+0x2c/0x38 |
| [ 5.561160] device_add+0x2d8/0x768 |
| [ 5.565148] device_register+0x28/0x38 |
| [ 5.568537] coresight_register+0xf8/0x320 |
| [ 5.572358] cti_probe+0x1b0/0x3f0 |
| |
| ... |
| |
| Fix this by initializing the attributes when they are allocated. |
| |
| Fixes: 3c5597e39812 ("coresight: cti: Add connection information to sysfs") |
| Reported-by: Leo Yan <leo.yan@linaro.org> |
| Tested-by: Leo Yan <leo.yan@linaro.org> |
| Cc: Mike Leach <mike.leach@linaro.org> |
| Cc: Mathieu Poirier <mathieu.poirier@linaro.org> |
| Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> |
| Cc: stable <stable@vger.kernel.org> |
| Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> |
| Link: https://lore.kernel.org/r/20201029164559.1268531-2-mathieu.poirier@linaro.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/hwtracing/coresight/coresight-cti-sysfs.c | 7 +++++++ |
| 1 file changed, 7 insertions(+) |
| |
| --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c |
| +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c |
| @@ -1065,6 +1065,13 @@ static int cti_create_con_sysfs_attr(str |
| } |
| eattr->var = con; |
| con->con_attrs[attr_idx] = &eattr->attr.attr; |
| + /* |
| + * Initialize the dynamically allocated attribute |
| + * to avoid LOCKDEP splat. See include/linux/sysfs.h |
| + * for more details. |
| + */ |
| + sysfs_attr_init(con->con_attrs[attr_idx]); |
| + |
| return 0; |
| } |
| |