Beata Michalska 606a5d4227 opp: Don't drop extra references to OPPs accidentally ... We are required to call dev_pm_opp_put() from outside of the opp_table->lock as debugfs removal needs to happen lock-less to avoid circular dependency issues. commit cf1fac943c ("opp: Reduce the size of critical section in _opp_kref_release()") tried to fix that introducing a new routine _opp_get_next() which keeps returning OPPs that can be freed by the callers and this routine shall be called without holding the opp_table->lock. Though the commit overlooked the fact that the OPPs can be referenced by other users as well and this routine will end up dropping references which were taken by other users and hence freeing the OPPs prematurely. In effect, other users of the OPPs will end up having invalid pointers at hand. We didn't see any crash reports earlier as the exact situation never happened, though it is certainly possible. We need a way to mark which OPPs are no longer referenced by the OPP core, so we don't drop extra references to them accidentally. This commit adds another OPP flag, "removed", which is used to track this. And now we should never end up dropping extra references to the OPPs. Cc: v5.11+ <stable@vger.kernel.org> # v5.11+ Fixes: cf1fac943c ("opp: Reduce the size of critical section in _opp_kref_release()") Signed-off-by: Beata Michalska <beata.michalska@arm.com> [ Viresh: Almost rewrote entire patch, added new "removed" field, rewrote commit log and added the correct Fixes tag. ] Co-developed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>		2021-03-12 09:26:52 +05:30
..
Kconfig	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
core.c	opp: Don't drop extra references to OPPs accidentally	2021-03-12 09:26:52 +05:30
cpu.c	opp: Remove _dev_pm_opp_find_and_remove_table() wrapper	2020-08-24 17:04:37 +05:30
debugfs.c	opp: Expose bandwidth information via debugfs	2020-05-29 10:15:12 +05:30
of.c	opp: Allow lazy-linking of required-opps	2021-02-02 10:30:53 +05:30
opp.h	opp: Don't drop extra references to OPPs accidentally	2021-03-12 09:26:52 +05:30
ti-opp-supply.c	opp: ti-opp-supply: Replace HTTP links with HTTPS ones	2020-07-24 08:05:54 +05:30