| Message ID | 20220331083018.31995-1-xiam0nd.tong@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] opp: use list iterator only inside the loop | expand |
On 31-03-22, 16:30, Xiaomeng Tong wrote: > To move the list iterator variable into the list_for_each_entry_*() > macro in the future it should be avoided to use the list iterator > variable after the loop body. > > To *never* use the list iterator variable after the loop it was > concluded to use a separate dedicated pointer variable [1]. > > In this case, use a new variable 'iter' as the list iterator, while > use the old variable 'new_dev' as a dedicated pointer to point to the > found entry. And BUG_ON(!new_dev);. > > [1]: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ > > Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> > --- Applied. Thanks.
diff --git a/drivers/opp/debugfs.c b/drivers/opp/debugfs.c index 596c185b5dda..81b2bc4b5f43 100644 --- a/drivers/opp/debugfs.c +++ b/drivers/opp/debugfs.c @@ -187,14 +187,18 @@ void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table) static void opp_migrate_dentry(struct opp_device *opp_dev, struct opp_table *opp_table) { - struct opp_device *new_dev; + struct opp_device *new_dev = NULL, *iter; const struct device *dev; struct dentry *dentry; /* Look for next opp-dev */ - list_for_each_entry(new_dev, &opp_table->dev_list, node) - if (new_dev != opp_dev) + list_for_each_entry(iter, &opp_table->dev_list, node) + if (iter != opp_dev) { + new_dev = iter; break; + } + + BUG_ON(!new_dev); /* new_dev is guaranteed to be valid here */ dev = new_dev->dev;
To move the list iterator variable into the list_for_each_entry_*() macro in the future it should be avoided to use the list iterator variable after the loop body. To *never* use the list iterator variable after the loop it was concluded to use a separate dedicated pointer variable [1]. In this case, use a new variable 'iter' as the list iterator, while use the old variable 'new_dev' as a dedicated pointer to point to the found entry. And BUG_ON(!new_dev);. [1]: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> --- changes since v1: - use BUG_ON(!new_dev); instead of return; (Viresh Kumar) v1: https://lore.kernel.org/lkml/20220331015818.28045-1-xiam0nd.tong@gmail.com/ --- drivers/opp/debugfs.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)