From ed5207afc580937cd6cc671357fe1119f1b5b0f5 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Fri, 5 Jul 2019 17:14:24 +0300 Subject: intel_th: msu: Prevent freeing buffers while locked windows exist 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 Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20190705141425.19894-5-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/intel_th/msu.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/hwtracing') diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c index a6c0eb09c515..b200d9d1c7a0 100644 --- a/drivers/hwtracing/intel_th/msu.c +++ b/drivers/hwtracing/intel_th/msu.c @@ -724,6 +724,11 @@ static int msc_win_set_lockout(struct msc_window *win, win->lockout = new; + 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); + unlock: spin_unlock_irqrestore(&win->lo_lock, flags); -- cgit v1.2.3