On Fri, 29 May 2026 00:52:01 +0800, Runyu Xiao wrote:

The etb10 miscdevice uses drvdata->reading as a shared exclusivity gate for userspace buffer access. etb_open() claims that gate with local_cmpxchg(), and etb_release() clears it with local_set().

That gate is shared per-device state rather than CPU-local state. A running system can reach it whenever /dev/<etb> is opened, closed, and reopened by different tasks while the device remains registered, so the same drvdata->reading variable may be claimed on one CPU and later cleared on another.

[...]

Applied, thanks!

[1/1] coresight: etb10: restore atomic_t for shared reading state https://git.kernel.org/coresight/c/fa09f08ede3d

Best regards,