[PATCH v10 0/5] Extended MODVERSIONS Support

[Luis Chamberlain]

On Sat, Nov 23, 2024 at 02:42:14AM +0000, Matthew Maurer wrote:
> This patch series is intended for use alongside the Implement DWARF
> modversions series [1] to enable RUST and MODVERSIONS at the same
> time.
> 
> Elsewhere, we've seen a desire for long symbol name support for LTO
> symbol names [2], and the previous series came up [3] as a possible
> solution rather than hashing, which some have objected [4] to.
> 
> This series adds a MODVERSIONS format which uses a section per column.
> This avoids userspace tools breaking if we need to make a similar change
> to the format in the future - we would do so by adding a new section,
> rather than editing the struct definition. In the new format, the name
> section is formatted as a concatenated sequence of NUL-terminated
> strings, which allows for arbitrary length names.
> 
> Emitting the extended format is guarded by CONFIG_EXTENDED_MODVERSIONS,
> but the kernel always knows how to validate both the original and
> extended formats.
> 
> Emitting the existing format is now guarded by CONFIG_BASIC_MODVERSIONS,
> but it is enabled by default when MODVERSIONS is enabled and must be
> explicitly disabled by the user.
> 
> Disabling CONFIG_BASIC_MODVERSIONS may cause some userspace tools to be
> unable to retrieve CRCs until they are patched to understand the new
> location. Even with CONFIG_BASIC_MODVERSIONS enabled, those tools will
> be unable to read the CRCs for long symbols until they are updated to
> read the new format. This is not expected to interfere with normal
> operation, as the primary use for CRCs embedded in the module is
> load-time verification by the kernel. Recording and monitoring of CRCs
> is typically done through Module.symvers.
> 
> Selecting RUST and MODVERSIONS is now possible if GENDWARFKSYMS is
> selected, and will implicitly select EXTENDED_MODVERSIONS.
> 
> This series depends upon the module verification refactor patches [5]
> that were split off of v5 (now in modules-next)
> and DWARF-based versions [1].

Thanks for doing all this.

Acked-by: Luis Chamberlain <mcgrof at kernel.org>

 Luis