From: Mukesh Ojha quic_mojha@quicinc.com
stable inclusion from stable-v4.19.302 commit 49d11d329a92f348d3e6bcac9ebfe05d785f1bb1 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8T1U8
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit af54d778a03853801d681c98c0c2a6c316ef9ca7 ]
dev_coredumpm() creates a devcoredump device and adds it to the core kernel framework which eventually end up sending uevent to the user space and later creates a symbolic link to the failed device. An application running in userspace may be interested in this symbolic link to get the name of the failed device.
In a issue scenario, once uevent sent to the user space it start reading '/sys/class/devcoredump/devcdX/failing_device' to get the actual name of the device which might not been created and it is in its path of creation.
To fix this, suppress sending uevent till the failing device symbolic link gets created and send uevent once symbolic link is created successfully.
Fixes: 833c95456a70 ("device coredump: add new device coredump class") Signed-off-by: Mukesh Ojha quic_mojha@quicinc.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1700232572-25823-1-git-send-email-quic_mojha@quici... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zhang Zekun zhangzekun11@huawei.com --- drivers/base/devcoredump.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index 7a5e4971943c..7f74a1f61d0c 100644 --- a/drivers/base/devcoredump.c +++ b/drivers/base/devcoredump.c @@ -376,6 +376,7 @@ void dev_coredumpm(struct device *dev, struct module *owner, devcd->devcd_dev.class = &devcd_class;
mutex_lock(&devcd->mutex); + dev_set_uevent_suppress(&devcd->devcd_dev, true); if (device_add(&devcd->devcd_dev)) goto put_device;
@@ -387,6 +388,8 @@ void dev_coredumpm(struct device *dev, struct module *owner, "devcoredump")) /* nothing - symlink will be missing */;
+ dev_set_uevent_suppress(&devcd->devcd_dev, false); + kobject_uevent(&devcd->devcd_dev.kobj, KOBJ_ADD); INIT_DELAYED_WORK(&devcd->del_wk, devcd_del); schedule_delayed_work(&devcd->del_wk, DEVCD_TIMEOUT); mutex_unlock(&devcd->mutex);