[PATCH] check-uapi: reject zero and malformed job counts

[PATCH] check-uapi: reject zero and malformed job counts

[omer zalman]

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With -j 0, the per-header loop waits on an empty PID before any
worker starts. It counts that wait error as an ABI failure even when
the header passes. Reject non-positive or malformed job counts as
prerequisite errors before starting the check.

Signed-off-by: Omer Zalman <omerzalman42@gmail.com>

The exact git-format-patch file is attached because Gmail's web
composer removes tabs from inline diffs.

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From 37e0d18b7aaa621981ac1433fd4dbdac72194694 Mon Sep 17 00:00:00 2001
From: Omer Zalman <omerzalman42@gmail.com>
Date: Sun, 27 Sep 2026 08:41:10 -0400
Subject: [PATCH] check-uapi: reject zero and malformed job counts
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>, John Moon <quic_johmoo@quicinc.com>, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org

From: Omer Zalman <omerzalman42@gmail.com>

With -j 0, the per-header loop waits on an empty PID before any
worker starts. It counts that wait error as an ABI failure even when
the header passes. Reject non-positive or malformed job counts as
prerequisite errors before starting the check.

Signed-off-by: Omer Zalman <omerzalman42@gmail.com>
---
 scripts/check-uapi.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/scripts/check-uapi.sh b/scripts/check-uapi.sh
index e349d1f..a5b5995 100644
--- a/scripts/check-uapi.sh
+++ b/scripts/check-uapi.sh
@@ -575,6 +575,11 @@ main() {
 		exec > /dev/null 2>&1
 	fi
 
+	if ! [[ "$MAX_THREADS" =~ ^0*[1-9][0-9]*$ ]]; then
+		eprintf 'error - JOBS must be a positive integer\n'
+		exit "$FAIL_PREREQ"
+	fi
+
 	run "$base_ref" "$past_ref" "$abi_error_log" "$@"
 }
 

Re: [PATCH] check-uapi: reject zero and malformed job counts

[Greg KH]

On Mon, Sep 28, 2026 at 07:44:32PM -0400, omer zalman wrote:
> With -j 0, the per-header loop waits on an empty PID before any
> worker starts. It counts that wait error as an ABI failure even when
> the header passes. Reject non-positive or malformed job counts as
> prerequisite errors before starting the check.
> 
> Signed-off-by: Omer Zalman <omerzalman42@gmail.com>
> 
> The exact git-format-patch file is attached because Gmail's web
> composer removes tabs from inline diffs.

Please do not use gmail web interface for patches, the email
documentation in the kernel should explain how to do this properly.

thanks,

greg k-h