Re: [PATCH v3 2/2] s390: Warn if kernel command line contains non-printable EBCDIC characters

[sashiko-bot@kernel.org]

> Users may accidentally add multi-byte UTF-8 characters to zipl.conf
> parmline, for example, by copying snippets containing non-breaking
> spaces (\xC2\xA0) from web pages.
> 
> The kernel will then interpret the entire command line as EBCDIC,
> making it unusable. Distinguish this situation from the legitimate
> EBCDIC conversion by looking for non-printable characters and issue
> a warning.
> 
> The current solution deliberately makes the following tradeoffs:
> 
> * Do not make this a hard failure, there may be a very small number
>   of users who put characters with diacritics on their EBCDIC-encoded
>   command lines.
> * Do not use heuristics with arbitrary thresholds, these may fail
>   intermittently on, e.g., punctuation-heavy command lines, and having
>   to tune thresholds in subsequent patches is not desirable.
> * Use the invariant subset of EBCDIC to determine whether characters
>   are printable, the vast majority of command lines will contain
>   characters from this subset.
> 
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260828140057.1728173-1-iii@linux.ibm.com?part=2