| Message ID | 20230804092636.91357-1-lizetao1@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [net-next] net/mlx5: Devcom, only use devcom after NULL check in mlx5_devcom_send_event() | expand |
On 04/08/2023 10:26, Li Zetao wrote: > There is a warning reported by kernel test robot: > > smatch warnings: > drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c:264 > mlx5_devcom_send_event() warn: variable dereferenced before > IS_ERR check devcom (see line 259) > > The reason for the warning is that the pointer is used before check, put > the assignment to comp after devcom check to silence the warning. > > Fixes: 88d162b47981 ("net/mlx5: Devcom, Infrastructure changes") > Reported-by: kernel test robot <lkp@intel.com> > Reported-by: Dan Carpenter <error27@gmail.com> > Closes: https://lore.kernel.org/r/202308041028.AkXYDwJ6-lkp@intel.com/ > Signed-off-by: Li Zetao <lizetao1@huawei.com> > --- > drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c > index feb62d952643..2bc18274858c 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c > @@ -256,7 +256,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom_comp_dev *devcom, > int event, int rollback_event, > void *event_data) > { > - struct mlx5_devcom_comp *comp = devcom->comp; > + struct mlx5_devcom_comp *comp; > struct mlx5_devcom_comp_dev *pos; The code should end up with reverse x-mas tree order. The change itself LGTM. > int err = 0; > void *data; > @@ -264,6 +264,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom_comp_dev *devcom, > if (IS_ERR_OR_NULL(devcom)) > return -ENODEV; > > + comp = devcom->comp; > down_write(&comp->sem); > list_for_each_entry(pos, &comp->comp_dev_list_head, list) { > data = rcu_dereference_protected(pos->data, lockdep_is_held(&comp->sem));
On 04/08/2023 23:53, Vadim Fedorenko wrote: > On 04/08/2023 10:26, Li Zetao wrote: >> There is a warning reported by kernel test robot: >> >> smatch warnings: >> drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c:264 >> mlx5_devcom_send_event() warn: variable dereferenced before >> IS_ERR check devcom (see line 259) >> >> The reason for the warning is that the pointer is used before check, put >> the assignment to comp after devcom check to silence the warning. >> >> Fixes: 88d162b47981 ("net/mlx5: Devcom, Infrastructure changes") >> Reported-by: kernel test robot <lkp@intel.com> >> Reported-by: Dan Carpenter <error27@gmail.com> >> Closes: https://lore.kernel.org/r/202308041028.AkXYDwJ6-lkp@intel.com/ >> Signed-off-by: Li Zetao <lizetao1@huawei.com> >> --- >> drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c >> index feb62d952643..2bc18274858c 100644 >> --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c >> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c >> @@ -256,7 +256,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom_comp_dev *devcom, >> int event, int rollback_event, >> void *event_data) >> { >> - struct mlx5_devcom_comp *comp = devcom->comp; >> + struct mlx5_devcom_comp *comp; >> struct mlx5_devcom_comp_dev *pos; > > The code should end up with reverse x-mas tree order. > The change itself LGTM. > Hi Li, Are you going to submit v2 ? Thanks, Roi >> int err = 0; >> void *data; >> @@ -264,6 +264,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom_comp_dev *devcom, >> if (IS_ERR_OR_NULL(devcom)) >> return -ENODEV; >> + comp = devcom->comp; >> down_write(&comp->sem); >> list_for_each_entry(pos, &comp->comp_dev_list_head, list) { >> data = rcu_dereference_protected(pos->data, lockdep_is_held(&comp->sem)); >
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c index feb62d952643..2bc18274858c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c @@ -256,7 +256,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom_comp_dev *devcom, int event, int rollback_event, void *event_data) { - struct mlx5_devcom_comp *comp = devcom->comp; + struct mlx5_devcom_comp *comp; struct mlx5_devcom_comp_dev *pos; int err = 0; void *data; @@ -264,6 +264,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom_comp_dev *devcom, if (IS_ERR_OR_NULL(devcom)) return -ENODEV; + comp = devcom->comp; down_write(&comp->sem); list_for_each_entry(pos, &comp->comp_dev_list_head, list) { data = rcu_dereference_protected(pos->data, lockdep_is_held(&comp->sem));
There is a warning reported by kernel test robot: smatch warnings: drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c:264 mlx5_devcom_send_event() warn: variable dereferenced before IS_ERR check devcom (see line 259) The reason for the warning is that the pointer is used before check, put the assignment to comp after devcom check to silence the warning. Fixes: 88d162b47981 ("net/mlx5: Devcom, Infrastructure changes") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/r/202308041028.AkXYDwJ6-lkp@intel.com/ Signed-off-by: Li Zetao <lizetao1@huawei.com> --- drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)