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authorAlexander Shishkin <alexander.shishkin@linux.intel.com>2019-07-05 17:14:24 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-25 13:03:19 +0200
commited5207afc580937cd6cc671357fe1119f1b5b0f5 (patch)
treead448f597fecc9421936cf8ae2e086253f7e1902 /drivers/hwtracing/intel_th
parent57b69a1f66486d632e188fb167950fb4bdf84221 (diff)
downloadlinux-ed5207afc580937cd6cc671357fe1119f1b5b0f5.tar.bz2
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 <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>
Diffstat (limited to 'drivers/hwtracing/intel_th')
-rw-r--r--drivers/hwtracing/intel_th/msu.c5
1 files changed, 5 insertions, 0 deletions
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);