From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 47AB62DFA3A for ; Wed, 7 Oct 2026 00:50:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791334209; cv=none; b=uKMPJMJGqkZazUxcB/BINdRr9F+zuL+lLwgYUH5ogE6xYKPQKhaF0gHv2NzCTE/EibI8gAKABP4ohauBo/D2dKKXoXsoIHPIea2RTVeiytd63fAlEAGU82Koc4CBP4MDKvI3Gwhd65raTzOJfmsIUuEyZeRqzENXLK4b+edlB3M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791334209; c=relaxed/simple; bh=GaImOTGT2vIR5l6FoAHG3AoSmt3SxbRwapo1vE5roIQ=; h=Date:To:From:Subject:Message-Id; b=k7cGi8Xk7/47FLb1CFZFC9Wf/wW4gs4mqJZ6E9RtDyKCHIDG0Gjgu08+MM+YyZEL2Yqt/fraV8o9kpv3YThJf/Qafp8fkLHVULFGoh23P1McuzlxD3DWsoJ91WLmKNlySbrBkmp0xpHDKVE2QM8rDgiLFHpB5WIZBmaR8MgxMAU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=T9RoTR3K; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="T9RoTR3K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 964711F0089E; Wed, 7 Oct 2026 00:50:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1791334207; bh=O2WWcxLxJTOs1dvuKt6zBiVpXbdnqfKCC2+9ztR3GQw=; h=Date:To:From:Subject; b=T9RoTR3KtFUWWVYQxfbrxv+bSxsWnBftUE2AJaoTONc5EnDaHHf80q8PcwwVxYxZ3 oD6fmRdnpRIxqbpcoUFHBm0yEvtZS6rr/8ZN1SdLfMbPqhjA0yVLfBXBDrDEnI5JI2 6FrxfF+aAHjcu858OvQBg3ITK1OV9fAfnS/FCUGg= Date: Tue, 06 Oct 2026 17:50:07 -0700 To: mm-commits@vger.kernel.org,tj@kernel.org,shuah@kernel.org,nphamcs@gmail.com,mkoutny@suse.com,hannes@cmpxchg.org,chengming.zhou@linux.dev,wfelipe@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] selftests-cgroup-test_zswap-fix-implicit-unsigned-promotion-bug-in-test_no_kmem_bypass.patch removed from -mm tree Message-Id: <20261007005007.964711F0089E@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: selftests/cgroup: test_zswap: fix implicit unsigned promotion bug in test_no_kmem_bypass has been removed from the -mm tree. Its filename was selftests-cgroup-test_zswap-fix-implicit-unsigned-promotion-bug-in-test_no_kmem_bypass.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Wilson Felipe Pereira Subject: selftests/cgroup: test_zswap: fix implicit unsigned promotion bug in test_no_kmem_bypass Date: Fri, 28 Aug 2026 03:37:32 +0000 In test_no_kmem_bypass(), delta (stored_pages * page_size - zswapped) is checked against stored_pages * page_size / 4 to verify that the pages pushed to zswap belong to the test memory cgroup. Due to slight stat update timing differences, delta can evaluate to a small negative number (e.g. -5MB out of 1GB). Because delta is declared as a signed int and stored_pages is an unsigned size_t, C's usual arithmetic conversions implicitly promote a negative delta to a large unsigned 64-bit integer, causing `delta < stored_pages * page_size / 4` to falsely evaluate to 0 and fail the test. Fix this by declaring zswapped and delta as signed long long and comparing against a signed threshold, ensuring negative deltas correctly evaluate to true. Link: https://lore.kernel.org/20260828033741.2184560-3-wfelipe@google.com Fixes: a549f9f31561a ("selftests: cgroup: add test_zswap with no kmem bypass test") Signed-off-by: Wilson Felipe Pereira Signed-off-by: Andrew Morton Acked-by: Michal Koutný Cc: Chengming Zhou Cc: Johannes Weiner Cc: Nhat Pham Cc: Shuah Khan Cc: Tejun Heo --- tools/testing/selftests/cgroup/test_zswap.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/tools/testing/selftests/cgroup/test_zswap.c~selftests-cgroup-test_zswap-fix-implicit-unsigned-promotion-bug-in-test_no_kmem_bypass +++ a/tools/testing/selftests/cgroup/test_zswap.c @@ -654,11 +654,14 @@ static int test_no_kmem_bypass(const cha break; /* If memory was pushed to zswap, verify it belongs to memcg */ if (stored_pages > stored_pages_threshold) { - int zswapped = cg_read_key_long(test_group, "memory.stat", "zswapped "); - int delta = stored_pages * page_size - zswapped; - int result_ok = delta < stored_pages * page_size / 4; + long zswapped = cg_read_key_long( + test_group, "memory.stat", "zswapped "); + long long delta = + (long long)stored_pages * page_size - zswapped; + long long max_delta = + (long long)stored_pages * page_size / 4; - ret = result_ok ? KSFT_PASS : KSFT_FAIL; + ret = (delta < max_delta) ? KSFT_PASS : KSFT_FAIL; break; } } _ Patches currently in -mm which might be from wfelipe@google.com are mm-zswap-convert-zswap_store_page-and-zswap_compress-to-take-a-folio.patch init-main-fix-off-by-one-in-argv_init-cleanup.patch init-main-fix-false-positive-kernel-panic-on-environment-variable-overwrite.patch