Thanks for your reply.
On 2024/8/15 19:39, NeilBrown wrote:
On Thu, 15 Aug 2024, Kunwu Chan wrote:
Thanks for your reply.
On 2024/8/14 18:28, NeilBrown wrote:
On Wed, 14 Aug 2024, kunwu.chan@xxxxxxxxx wrote:
From: Kunwu Chan <chentao@xxxxxxxxxx>
Increase size of the servername array to avoid truncated output warning.
net/sunrpc/clnt.c:582:75: error：‘%s’ directive output may be truncated
writing up to 107 bytes into a region of size 48
[-Werror=format-truncation=]
582 | snprintf(servername, sizeof(servername), "%s",
| ^~
net/sunrpc/clnt.c:582:33: note:‘snprintf’ output
between 1 and 108 bytes into a destination of size 48
582 | snprintf(servername, sizeof(servername), "%s",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
583 | sun->sun_path);
Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
---
net/sunrpc/clnt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 09f29a95f2bc..874085f3ed50 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -546,7 +546,7 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
.connect_timeout = args->connect_timeout,
.reconnect_timeout = args->reconnect_timeout,
};
- char servername[48];
+ char servername[108];
If we choose this approach to removing the warning, then we should use
UNIX_PATH_MAX rather than 108.
My negligence.
However the longest server name copied in here will in practice be
/var/run/rpcbind.sock
so the extra 60 bytes on the stack is wasted ... maybe that doesn't
matter.
I'm thinking about use a dynamic space alloc method like kasprintf to
avoid space waste.
The string is only used by xprt_create_transport() which requires it to
be less than RPC_MAXNETNAMELEN - which is 256.
So maybe that would be a better value to use for the array size .... if
we assume that stack space isn't a problem.
Thank you for the detailed explanation. I read the
xprt_create_transport, the RPC_MAXNETNAMELEN
is only use to xprt_create_transport .
What ever number we use, I'd rather it was a defined constant, and not
an apparently arbitrary number.
Whether we could check the sun->sun_path length before using snprintf?
The array size should smaller
than the minimum of sun->sun_path and RPC_MAXNETNAMELEN.
Or use the dynamic space allocate method to save space.
I think that dynamically allocating space is not a good idea. It means
you have to handle failure which is just a waste of code.
I'd suggest simply changing the array to RPC_MAXNETNAMELEN.
I'll follow your suggestion and change it in v2.
NeilBrown
Thanks,
NeilBrown
struct rpc_clnt *clnt;
int i;
--
2.40.1
--
Thanks,
Kunwu.Chan
--
Thanks,
Kunwu.Chan
