Commit 64aaeb70 authored by Viresh Kumar's avatar Viresh Kumar
Browse files

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: default avatarStephan Gerhold <stephan.gerhold@kernkonzept.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Tested-by: default avatarStephan Gerhold <stephan.gerhold@kernkonzept.com>
parent 167eb2bd

drivers/opp/of.c

+12 −2
Original line number Diff line number Diff line
@@ -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);