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From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Jeff Layton <jlayton@kernel.org>
CC:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH] SUNRPC: Fix xdr_encode_bool()
Thread-Topic: [PATCH] SUNRPC: Fix xdr_encode_bool()
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Date:   Tue, 19 Jul 2022 16:51:56 +0000
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> On Jul 19, 2022, at 11:49 AM, Jeff Layton <jlayton@kernel.org> wrote:
>=20
> 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.
>>=20
>> The result was the encoded results of NFSv3 PATHCONF operations were
>> not formed correctly.
>>=20
>> Fixes: ded04a587f6c ("NFSD: Update the NFSv3 PATHCONF3res encoder to use=
 struct xdr_stream")
>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
>> ---
>> include/linux/sunrpc/xdr.h |    4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>=20
>> 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(stru=
ct xdr_stream *xdr)
>>  */
>> static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
>> {
>> -	*p =3D n ? xdr_one : xdr_zero;
>> -	return p++;
>> +	*p++ =3D n ? xdr_one : xdr_zero;
>> +	return p;
>> }
>>=20
>> /**
>>=20
>>=20
>=20
> Nice catch. Postincrement operators strike again!

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


> Reviewed-by: Jeff Layton <jlayton@kernel.org>


--
Chuck Lever