2022-07-19 14:06:19

by Chuck Lever III

Subject: [PATCH] SUNRPC: Fix xdr_encode_bool()

I discovered that xdr_encode_bool() was returning the same address
that was passed in the @p parameter. The documenting comment states
that the intent is to return the address of the next buffer
location, just like the other "xdr_encode_*" helpers.

The result was the encoded results of NFSv3 PATHCONF operations were
not formed correctly.

Fixes: ded04a587f6c ("NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream")
Signed-off-by: Chuck Lever <[email protected]>
---
include/linux/sunrpc/xdr.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 5860f32e3958..986c8a17ca5e 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -419,8 +419,8 @@ static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
*/
static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
{
- *p = n ? xdr_one : xdr_zero;
- return p++;
+ *p++ = n ? xdr_one : xdr_zero;
+ return p;
}

/**

2022-07-19 15:51:19

by Jeff Layton

Subject: Re: [PATCH] SUNRPC: Fix xdr_encode_bool()

On Tue, 2022-07-19 at 09:18 -0400, Chuck Lever wrote:
> I discovered that xdr_encode_bool() was returning the same address
> that was passed in the @p parameter. The documenting comment states
> that the intent is to return the address of the next buffer
> location, just like the other "xdr_encode_*" helpers.
>
> The result was the encoded results of NFSv3 PATHCONF operations were
> not formed correctly.
>
> Fixes: ded04a587f6c ("NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream")
> Signed-off-by: Chuck Lever <[email protected]>
> ---
> include/linux/sunrpc/xdr.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
> index 5860f32e3958..986c8a17ca5e 100644
> --- a/include/linux/sunrpc/xdr.h
> +++ b/include/linux/sunrpc/xdr.h
> @@ -419,8 +419,8 @@ static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
> */
> static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
> {
> - *p = n ? xdr_one : xdr_zero;
> - return p++;
> + *p++ = n ? xdr_one : xdr_zero;
> + return p;
> }
>
> /**
>
>

Nice catch. Postincrement operators strike again!

Reviewed-by: Jeff Layton <[email protected]>

2022-07-19 16:53:10

by Chuck Lever III

Subject: Re: [PATCH] SUNRPC: Fix xdr_encode_bool()

> On Jul 19, 2022, at 11:49 AM, Jeff Layton <[email protected]> wrote:
>
> On Tue, 2022-07-19 at 09:18 -0400, Chuck Lever wrote:
>> I discovered that xdr_encode_bool() was returning the same address
>> that was passed in the @p parameter. The documenting comment states
>> that the intent is to return the address of the next buffer
>> location, just like the other "xdr_encode_*" helpers.
>>
>> The result was the encoded results of NFSv3 PATHCONF operations were
>> not formed correctly.
>>
>> Fixes: ded04a587f6c ("NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream")
>> Signed-off-by: Chuck Lever <[email protected]>
>> ---
>> include/linux/sunrpc/xdr.h | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
>> index 5860f32e3958..986c8a17ca5e 100644
>> --- a/include/linux/sunrpc/xdr.h
>> +++ b/include/linux/sunrpc/xdr.h
>> @@ -419,8 +419,8 @@ static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
>> */
>> static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
>> {
>> - *p = n ? xdr_one : xdr_zero;
>> - return p++;
>> + *p++ = n ? xdr_one : xdr_zero;
>> + return p;
>> }
>>
>> /**
>>
>>
>
> Nice catch. Postincrement operators strike again!

The original patch description read "D'oh!".


> Reviewed-by: Jeff Layton <[email protected]>


--
Chuck Lever