Re: [PATCH 1/4] livepatch-build: allow patch file name sizes up to 127 characters

[Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>]

On Thu, Nov 7, 2024 at 3:15 PM Roger Pau Monne <roger.pau@xxxxxxxxxx> wrote:
>
> XenServer uses quite long Xen version names, and encode such in the livepatch
> filename, and it's currently running out of space in the file name.
>
> Bump max filename size to 127, so it also matches the patch name length in the
> hypervisor interface.  Note the size of the buffer is 128 characters, and the
> last one is reserved for the null terminator.
>
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> ---
> Changes since v1:
>  - Take into account the null terminator.
> ---
>  livepatch-build | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/livepatch-build b/livepatch-build
> index 948b2acfc2f6..f3ca9399d149 100755
> --- a/livepatch-build
> +++ b/livepatch-build
> @@ -72,8 +72,9 @@ function make_patch_name()
>      fi
>
>      # Only allow alphanumerics and '_' and '-' in the patch name.  Everything
> -    # else is replaced with '-'.  Truncate to 48 chars.
> -    echo ${PATCHNAME//[^a-zA-Z0-9_-]/-} |cut -c 1-48
> +    # else is replaced with '-'.  Truncate to 127 chars
> +    # (XEN_LIVEPATCH_NAME_SIZE - 1).
> +    echo ${PATCHNAME//[^a-zA-Z0-9_-]/-} |cut -c -127
>  }

I think this 48 char limit erroneously came from kpatch / Linux's module
name length limit and is therefore not relevant.

Reviewed-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>

Thanks