| Message ID | 20200904180647.21080-1-trix@redhat.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | i2c: amd_mp2: handle num is 0 input for i2c_amd_xfer | expand |
Acked-by: Elie Morisse <syniurge@gmail.com> Le ven. 4 sept. 2020 à 20:06, <trix@redhat.com> a écrit : > > From: Tom Rix <trix@redhat.com> > > clang static analyzer reports this problem > > i2c-amd-mp2-plat.c:174:9: warning: Branch condition evaluates > to a garbage value > return err ? err : num; > ^~~ > > err is not initialized, it depends on the being set in the > transfer loop which will not happen if num is 0. Surveying > other master_xfer() implementations show all handle a 0 num. > > Because returning 0 is expected, initialize err to 0. > > Signed-off-by: Tom Rix <trix@redhat.com> > --- > drivers/i2c/busses/i2c-amd-mp2-plat.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-amd-mp2-plat.c b/drivers/i2c/busses/i2c-amd-mp2-plat.c > index 17df9e8845b6..506433bc0ff2 100644 > --- a/drivers/i2c/busses/i2c-amd-mp2-plat.c > +++ b/drivers/i2c/busses/i2c-amd-mp2-plat.c > @@ -155,7 +155,7 @@ static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap); > int i; > struct i2c_msg *pmsg; > - int err; > + int err = 0; > > /* the adapter might have been deleted while waiting for the bus lock */ > if (unlikely(!i2c_dev->common.mp2_dev)) > -- > 2.18.1 >
On Fri, Sep 04, 2020 at 11:06:47AM -0700, trix@redhat.com wrote: > From: Tom Rix <trix@redhat.com> > > clang static analyzer reports this problem > > i2c-amd-mp2-plat.c:174:9: warning: Branch condition evaluates > to a garbage value > return err ? err : num; > ^~~ > > err is not initialized, it depends on the being set in the > transfer loop which will not happen if num is 0. Surveying > other master_xfer() implementations show all handle a 0 num. > > Because returning 0 is expected, initialize err to 0. Well, it is not expected. The core does: 2019 if (WARN_ON(!msgs || num < 1)) 2020 return -EINVAL; Dunno if we should apply the patch nonetheless or add a comment that num is guaranteed to be at least 1. > > Signed-off-by: Tom Rix <trix@redhat.com> > --- > drivers/i2c/busses/i2c-amd-mp2-plat.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-amd-mp2-plat.c b/drivers/i2c/busses/i2c-amd-mp2-plat.c > index 17df9e8845b6..506433bc0ff2 100644 > --- a/drivers/i2c/busses/i2c-amd-mp2-plat.c > +++ b/drivers/i2c/busses/i2c-amd-mp2-plat.c > @@ -155,7 +155,7 @@ static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap); > int i; > struct i2c_msg *pmsg; > - int err; > + int err = 0; > > /* the adapter might have been deleted while waiting for the bus lock */ > if (unlikely(!i2c_dev->common.mp2_dev)) > -- > 2.18.1 >
On Fri, Sep 04, 2020 at 11:06:47AM -0700, trix@redhat.com wrote: > From: Tom Rix <trix@redhat.com> > > clang static analyzer reports this problem > > i2c-amd-mp2-plat.c:174:9: warning: Branch condition evaluates > to a garbage value > return err ? err : num; > ^~~ > > err is not initialized, it depends on the being set in the > transfer loop which will not happen if num is 0. Surveying > other master_xfer() implementations show all handle a 0 num. > > Because returning 0 is expected, initialize err to 0. > > Signed-off-by: Tom Rix <trix@redhat.com> Applied to for-next, thanks!
diff --git a/drivers/i2c/busses/i2c-amd-mp2-plat.c b/drivers/i2c/busses/i2c-amd-mp2-plat.c index 17df9e8845b6..506433bc0ff2 100644 --- a/drivers/i2c/busses/i2c-amd-mp2-plat.c +++ b/drivers/i2c/busses/i2c-amd-mp2-plat.c @@ -155,7 +155,7 @@ static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap); int i; struct i2c_msg *pmsg; - int err; + int err = 0; /* the adapter might have been deleted while waiting for the bus lock */ if (unlikely(!i2c_dev->common.mp2_dev))