kernel/linux.git/include/linux/sunrpc/xdrgen, branch v6.12.80

xdrgen: Initialize data pointer for zero-length items

2026-03-04T12:20:05+00:00

[ Upstream commit 27b0fcae8f535fb882b1876227a935dcfdf576aa ] The xdrgen decoders for strings and opaque data had an optimization that skipped calling xdr_inline_decode() when the item length was zero. This left the data pointer uninitialized, which could lead to unpredictable behavior when callers access it. Remove the zero-length check and always call xdr_inline_decode(). When passed a length of zero, xdr_inline_decode() returns the current buffer position, which is valid and matches the behavior of hand-coded XDR decoders throughout the kernel. Fixes: 4b132aacb076 ("tools: Add xdrgen") Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin

xdrgen: Fix return code checking in built-in XDR decoders

2024-09-20T23:31:39+00:00

xdr_stream_encode_u32() returns XDR_UNIT on success. xdr_stream_decode_u32() returns zero or -EMSGSIZE, but never XDR_UNIT. Signed-off-by: Chuck Lever

tools: Add xdrgen

2024-09-20T23:31:39+00:00

Add a Python-based tool for translating XDR specifications into XDR encoder and decoder functions written in the Linux kernel's C coding style. The generator attempts to match the usual C coding style of the Linux kernel's SunRPC consumers. This approach is similar to the netlink code generator in tools/net/ynl . The maintainability benefits of machine-generated XDR code include: - Stronger type checking - Reduces the number of bugs introduced by human error - Makes the XDR code easier to audit and analyze - Enables rapid prototyping of new RPC-based protocols - Hardens the layering between protocol logic and marshaling - Makes it easier to add observability on demand - Unit tests might be built for both the tool and (automatically) for the generated code In addition, converting the XDR layer to use memory-safe languages such as Rust will be easier if much of the code can be converted automatically. Tested-by: Jeff Layton Signed-off-by: Chuck Lever