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intel_th: msu: Prevent freeing buffers while locked windows exist

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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 <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190705141425.19894-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexander Shishkin 2019-07-05 17:14:24 +03:00 committed by Greg Kroah-Hartman
parent 57b69a1f66
commit ed5207afc5
1 changed files with 5 additions and 0 deletions
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5
drivers/hwtracing/intel_th/msu.c
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@ -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);