From 64aaeb708245acdcbe51cf30c84418668c044d80 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 8 Jun 2023 13:10:14 +0530 Subject: OPP: Protect `lazy_opp_tables` list with `opp_table_lock` The `opp_table_lock` lock is already used to protect the list elsewhere, use it while adding or removing entries from it. Reported-by: Stephan Gerhold Signed-off-by: Viresh Kumar Tested-by: Stephan Gerhold --- drivers/opp/of.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/opp') diff --git a/drivers/opp/of.c b/drivers/opp/of.c index c740a907ef76..ac2179d5da4c 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -21,7 +21,7 @@ #include "opp.h" -/* OPP tables with uninitialized required OPPs */ +/* OPP tables with uninitialized required OPPs, protected by opp_table_lock */ static LIST_HEAD(lazy_opp_tables); /* @@ -148,7 +148,10 @@ static void _opp_table_free_required_tables(struct opp_table *opp_table) opp_table->required_opp_count = 0; opp_table->required_opp_tables = NULL; + + mutex_lock(&opp_table_lock); list_del(&opp_table->lazy); + mutex_unlock(&opp_table_lock); } /* @@ -197,8 +200,15 @@ static void _opp_table_alloc_required_tables(struct opp_table *opp_table, } /* Let's do the linking later on */ - if (lazy) + if (lazy) { + /* + * The OPP table is not held while allocating the table, take it + * now to avoid corruption to the lazy_opp_tables list. + */ + mutex_lock(&opp_table_lock); list_add(&opp_table->lazy, &lazy_opp_tables); + mutex_unlock(&opp_table_lock); + } else _update_set_required_opps(opp_table); -- cgit v1.2.3-70-g09d2