Re: [PATCH v1 00/25] Server-side RPC call header parsing overhaul

[Jeff Layton <jlayton@kernel.org>]

On Mon, 2023-01-02 at 12:05 -0500, Chuck Lever wrote:
> Happy new year, campers.
> 
> The following series has been percolating for quite a while, thanks
> to the extended 6.1-rc cycle. I'd like to get this work reviewed
> for possible inclusion in v6.3, so I'm starting early.
> 
> The purpose of this series is to replace the svc_get* macros in the
> Linux kernel server's RPC call header parsing code with xdr_stream
> helpers. I've measured no change in CPU utilization after the
> overhaul; svc_recv() and friends remain the highest CPU consumers by
> an order of magnitude.
> 
> Memory safety: Buffer bounds checking after decoding each XDR item
> is more memory-safe than the current decoding mechanism. Subsequent
> memory safety improvements to the xdr_stream helpers will benefit
> all who use them.
> 
> Audit friendliness: The new code has lots of comments and other
> clean-up to help align it with the relevant RPC specifications. The
> use of common helpers also makes the decoders easier to audit.
> 
> I've split the full series in half to make it easier to review. The
> patches posted here handle RPC call header decoding. Remaining
> patches, to be posted later, deal with RPC reply header encoding.
> 
> Yes, there are a lot of patches, but they are each small, easily
> chewed mechanical changes.
> 
> ---
> 
> Chuck Lever (25):
>       SUNRPC: Push svcxdr_init_decode() into svc_process_common()
>       SUNRPC: Move svcxdr_init_decode() into ->accept methods
>       SUNRPC: Add an XDR decoding helper for struct opaque_auth
>       SUNRPC: Convert svcauth_null_accept() to use xdr_stream
>       SUNRPC: Convert svcauth_unix_accept() to use xdr_stream
>       SUNRPC: Convert svcauth_tls_accept() to use xdr_stream
>       SUNRPC: Move the server-side GSS upcall to a noinline function
>       SUNRPC: Hoist common verifier decoding code into svcauth_gss_proc_init()
>       SUNRPC: Remove gss_read_common_verf()
>       SUNRPC: Remove gss_read_verf()
>       SUNRPC: Convert server-side GSS upcall helpers to use xdr_stream
>       SUNRPC: Replace read_u32_from_xdr_buf() with existing XDR helper
>       SUNRPC: Rename automatic variables in unwrap_integ_data()
>       SUNRPC: Convert unwrap_integ_data() to use xdr_stream
>       SUNRPC: Rename automatic variables in unwrap_priv_data()
>       SUNRPC: Convert unwrap_priv_data() to use xdr_stream
>       SUNRPC: Convert gss_verify_header() to use xdr_stream
>       SUNRPC: Clean up svcauth_gss_accept's NULL procedure check
>       SUNRPC: Convert the svcauth_gss_accept() pre-amble to use xdr_stream
>       SUNRPC: Hoist init_decode out of svc_authenticate()
>       SUNRPC: Re-order construction of the first reply fields
>       SUNRPC: Eliminate unneeded variable
>       SUNRPC: Decode most of RPC header with xdr_stream
>       SUNRPC: Remove svc_process_common's argv parameter
>       SUNRPC: Hoist svcxdr_init_decode() into svc_process()
> 
> 
>  fs/lockd/svc.c                    |   1 -
>  fs/nfs/callback_xdr.c             |   1 -
>  fs/nfsd/nfssvc.c                  |   1 -
>  include/linux/sunrpc/msg_prot.h   |   5 +
>  include/linux/sunrpc/xdr.h        |   5 +-
>  net/sunrpc/auth_gss/svcauth_gss.c | 512 ++++++++++++++++--------------
>  net/sunrpc/svc.c                  |  69 ++--
>  net/sunrpc/svc_xprt.c             |   1 -
>  net/sunrpc/svcauth.c              |  13 +-
>  net/sunrpc/svcauth_unix.c         | 132 +++++---
>  net/sunrpc/xdr.c                  |  50 ++-
>  11 files changed, 468 insertions(+), 322 deletions(-)
> 
> --
> Chuck Lever
> 

I went through the whole set and it's all a mostly logical set of
methodical changes. You can add:

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