Re: [PATCH v7 13/23] KVM: s390: Use arm64 code

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The AWK extraction script silently suppresses errors for unbalanced end markers if a valid block was already processed, potentially leading to silently dropped code.
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commit 695b985ed66a46463a7810ac95a1f61e48477f7a
Author: Steffen Eiden <seiden@linux.ibm.com>

KVM: s390: Use arm64 code

This commit adds infrastructure to extract KVM/arm64 code into s390 at build
time. It introduces copy-arm64c.awk to detect ARM64_S390_COMMON markers and
extract marked sections into .inc files.

> diff --git a/arch/s390/kvm/arm64/copy-arm64c.awk b/arch/s390/kvm/arm64/copy-arm64c.awk
> new file mode 100644
> index 0000000000000..20bd73c52ec48
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/copy-arm64c.awk
[ ... ]
> +$0 ~ end_pattern {
> +	if (!copying) { exit 1 }
> +	copying = 0
> +	next
> +}
[ ... ]
> +END {
> +	exit !found_marker || copying
> +}

[Severity: Medium]
Does the END block unintentionally suppress errors from unbalanced end markers?

If a source file contains a valid ARM64_S390_COMMON block, found_marker
becomes 1 and copying becomes 0 after it finishes. If an extra, unbalanced end
marker is encountered later in the file, the end_pattern block evaluates
if (!copying) and calls exit 1.

However, when exit 1 is called, awk proceeds to the END block. Since
found_marker is 1 and copying is 0, the expression !found_marker || copying
evaluates to 0. This causes the script to override the exit 1 with an exit 0,
silently returning success and stopping file processing instead of failing the
build.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260831144802.834315-1-seiden@linux.ibm.com?part=13