We already prevent freeing buffers via sysfs interface in case there are existing users or if trace is active. Treat the existence of locked windows similarly and return -EBUSY on attempts to free the buffer. When the last window is unlocked, the freeing will succeed.
Signed-off-by: Alexander Shishkin <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> --- drivers/hwtracing/intel_th/msu.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c index fc9890e56e5b..f2d52c025528 100644 --- a/drivers/hwtracing/intel_th/msu.c +++ b/drivers/hwtracing/intel_th/msu.c @@ -703,6 +703,11 @@ static int msc_win_set_lockout(struct msc_window *win, int expect, int new) if (expect == WIN_LOCKED && old == new) return 0; + if (old == expect && new == WIN_LOCKED) + atomic_inc(&win->msc->user_count); + else if (old == expect && old == WIN_LOCKED) + atomic_dec(&win->msc->user_count); + if (WARN_ONCE(old != expect, "expected lockout state %d, got %d\n", expect, old)) return -EINVAL; -- 2.20.1
