sparse was unable to verify endianness correctness due to reassignment
from le32_to_cpu to the same variable - fix this warning up by providing
a proper __le32 type and initializing it. This is not actually fixing
any bug - rather just addressing the sparse warning.
Signed-off-by: Nicholas Mc Guire <[email protected]>
---
Problem located by an experimental coccinelle script to locate
patters that make sparse unhappy (false positives):
sparse was unhappy about:
net/qrtr/qrtr.c:811:24: warning: cast to restricted __le32
The patch does change the binary - from inspection of the .lst files
it seems that the additional variable as well instruction reordering
constraints change the code even if the code-logic is the same.
Patch was compile-tested with: qcom_defconfig + QRTR=m
Patch is against 5.1 (localversion-next is next-20190509)
net/qrtr/qrtr.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index dd0e97f..c90edaa 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -733,7 +733,8 @@ static int qrtr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
struct qrtr_node *node;
struct sk_buff *skb;
size_t plen;
- u32 type = QRTR_TYPE_DATA;
+ u32 type = 0;
+ __le32 qrtr_type = cpu_to_le32(QRTR_TYPE_DATA);
int rc;
if (msg->msg_flags & ~(MSG_DONTWAIT))
@@ -807,8 +808,8 @@ static int qrtr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
}
/* control messages already require the type as 'command' */
- skb_copy_bits(skb, 0, &type, 4);
- type = le32_to_cpu(type);
+ skb_copy_bits(skb, 0, &qrtr_type, 4);
+ type = le32_to_cpu(qrtr_type);
}
rc = enqueue_fn(node, skb, type, &ipc->us, addr);
--
2.1.4
From: Nicholas Mc Guire <[email protected]>
Date: Fri, 10 May 2019 03:08:53 +0200
> diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
> index dd0e97f..c90edaa 100644
> --- a/net/qrtr/qrtr.c
> +++ b/net/qrtr/qrtr.c
> @@ -733,7 +733,8 @@ static int qrtr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
> struct qrtr_node *node;
> struct sk_buff *skb;
> size_t plen;
> - u32 type = QRTR_TYPE_DATA;
> + u32 type = 0;
> + __le32 qrtr_type = cpu_to_le32(QRTR_TYPE_DATA);
> int rc;
Please try to preserve as much of the reverse chrimstas tree here rather
than making it worse.
Thank you.
On Fri, May 10, 2019 at 01:28:00PM -0700, David Miller wrote:
> From: Nicholas Mc Guire <[email protected]>
> Date: Fri, 10 May 2019 03:08:53 +0200
>
> > diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
> > index dd0e97f..c90edaa 100644
> > --- a/net/qrtr/qrtr.c
> > +++ b/net/qrtr/qrtr.c
> > @@ -733,7 +733,8 @@ static int qrtr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
> > struct qrtr_node *node;
> > struct sk_buff *skb;
> > size_t plen;
> > - u32 type = QRTR_TYPE_DATA;
> > + u32 type = 0;
> > + __le32 qrtr_type = cpu_to_le32(QRTR_TYPE_DATA);
> > int rc;
>
> Please try to preserve as much of the reverse chrimstas tree here rather
> than making it worse.
>
sorry - did not really think about that at all - will re-order the declarations and resend
thx!
hofrat