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authorSuzuki K Poulose <suzuki.poulose@arm.com>2020-10-29 19:45:58 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-29 22:10:25 +0300
commit80624263fa289b3416f7ca309491f1b75e579477 (patch)
tree70390910ed32194aa8e359d7dd856995243b00d4 /drivers/hwtracing
parent39a7661dcf655c8198fd5d72412f5030a8e58444 (diff)
downloadlinux-80624263fa289b3416f7ca309491f1b75e579477.tar.xz
coresight: cti: Initialize dynamic sysfs attributes
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>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight-cti-sysfs.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 392757f3a019..7ff7e7780bbf 100644
--- 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(struct device *dev,
}
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;
}