| Message ID | c0bac65236cf77fa8ac17c2645449544b73a0104.1686210112.git.viresh.kumar@linaro.org (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | viresh kumar |
| Headers | show |
| Series | [1/2] OPP: Staticize `lazy_opp_tables` in of.c | expand |
On Thu, Jun 08, 2023 at 01:13:23PM +0530, Viresh Kumar wrote: > 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 <stephan.gerhold@kernkonzept.com> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > Stephan: Can you please give this a try ? Thanks, works fine for me. (Note that I don't have any races or corruption without this patch either so the testing result might not mean too much.) The patch also looks good! Tested-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com> > > drivers/opp/of.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > 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); > > -- > 2.31.1.272.g89b43f80a514 >
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);
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 <stephan.gerhold@kernkonzept.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- Stephan: Can you please give this a try ? drivers/opp/of.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)