From nobody Mon Feb 9 11:38:08 2026 Received: from smtpbgeu1.qq.com (smtpbgeu1.qq.com [52.59.177.22]) (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 B0B9335EDB2; Wed, 14 Jan 2026 05:32:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.59.177.22 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768368762; cv=none; b=A70uSxDfg2M4llSUNqScBsb8v/BK4wYr/zD2i4SxvmsUsK8dczKNC7vFKcm4AYp9GFPld8nZr1spcs21gTgNKRJFYUDTYxF+eq68tNjVeTkuCWKxVuPKiilZFWWzOkrMqnhV+lA8hlFirR5SPU60a3DUQ7Vgx0dvwFKJGjIOT98= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768368762; c=relaxed/simple; bh=RgB2UdTm+24rF+4O4bAjYfUxAKD+cHQqt9VTHHJtUJk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=hbBdtdEZzLK3IZFJJ3XgzVnEBxZNLi5RDu0B12g2A4UGvI9mm4cxCTJTcRVt4t6qnvHMaHYSfm3n5+p7wF0xMhoMzCK12sSEvITba23J7my9Wab9U8A8hTEIsatzXhYM06/QnITlsomKMckKgV+4ys3DSFyNkhAHndLb0Pyw+h8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=uniontech.com; spf=pass smtp.mailfrom=uniontech.com; dkim=pass (1024-bit key) header.d=uniontech.com header.i=@uniontech.com header.b=IqrCaQBA; arc=none smtp.client-ip=52.59.177.22 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=uniontech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=uniontech.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=uniontech.com header.i=@uniontech.com header.b="IqrCaQBA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uniontech.com; s=onoh2408; t=1768368729; bh=FI7bkbgrIX+fBW6u4Ru5bB8HmN+BY5ejYxIceYoJcNw=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=IqrCaQBAlOK02L477cDk44Ard4G7syz9CyLssoodrF1L54QEcPSgJFkfsDtUcS+QX +WKsj20Crchuv1UWoEQ8EzHa+kUgQWWOGbpc51MoQZ63ne47Dgr5CgTKpCR8RBR1Ti Vl0yWd+K2NQRaf0uFIviJDEb4Iga8ueEVSNT5k90= X-QQ-mid: esmtpgz12t1768368698t2836aeba X-QQ-Originating-IP: X+7Y3qpth4VEaCUA6K/uKhUtNkMF/TiVYAMSZwThpTE= Received: from uos-PC ( [113.57.152.160]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 14 Jan 2026 13:31:36 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 1 X-BIZMAIL-ID: 15513342025828384446 EX-QQ-RecipientCnt: 6 From: Morduan Zang To: ardb@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: guanwentao@uniontech.com, zhangdandan@uniontech.com, niecheng1@uniontech.com Subject: [PATCH] efi/cper: Fix cper_bits_to_str buffer handling and return value Date: Wed, 14 Jan 2026 13:30:33 +0800 Message-ID: <7E55C4CEDE596906+20260114053033.124359-1-zhangdandan@uniontech.com> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-QQ-SENDSIZE: 520 Feedback-ID: esmtpgz:uniontech.com:qybglogicsvrgz:qybglogicsvrgz6b-0 X-QQ-XMAILINFO: MGsW0jV72LNN14RfY2Qrd24FJ88SZIt6EWOUvwgGLKCrOQfQ48GzhcNK Mw4GZqwaHT/KBZD3IJo03kN1IFfckBr0DY7vGqm+0vzXOB1UhV9COz9ZQ46WqPg7wm4NMXs OhfxYZ5KNmuDb24FVzr2PUS5pFoLw8NHLflxhv0yPb9uVj77C4PRI/CIWUnqu3H76XsBn6F F2hnrQdKfIFWWPcIwDjGJ7HaZMMq3Ivrg4ReoH6yZaf/581p18aYxaCbN++unRbbwBMvAJv XWU+cDdFk7qYMTiGyTv48lwRdesOZhQyte4wT2P5nR17G70a+9CsDo7j2JRbEiCxvWibl/K rV3SOV2rEr9pKQovjoBQfa4LIddzHa7S4+DelZ/wX166K4MzZrYw8GHRJzbmqXOG89stOMl KkT5+lRLXD0Sw2//0Do3OSz+qjRu963F/7qezNHXG8d/5U0DVb8Zlaxj3W1xal2g6Gr/LWH 8La5pvvpxBwLwa3UWoXhQ/CZSfR0fvVwJ/ZOdnbQYC9NY2zcSUIHLYvdBWE0nqgjd03tqcu tB0dWcIExJCX2BAewrpSoxCrpCt2LmxeoyRFlUF/RoNK4SuI0C+oCsnWJemROPP2eIsboxl 2adhIJ4ZGEr3IPRPG9WXdlsyKPXAbfLjfAwpahg+vklaIqKLo1jcwB5Q3Lyz8e+7ec71aX2 htC5xeEvYRioF27RBTi8eXxjqy4xu6F+hPDVwu7hEqnPP1i03wm3d5DZaBJOpc9Y0e2/Bqr DbOT8yYD2I3zCf793GFLpv1XsFjuXC9WbSKk5hqQ7EeWuuomw6M9EfKnqKZi8gdMHb2rtXF vayYPaSyv2hdCd0b5zmOubZQo/99QyrY8tZ8HG8vDGrLn8H/Z6vPxsD9D234raitxYliFED DAhs+7B54ZIEIL/g8to6bLUmivVdqHU88zLp3POEiC84K18pUHeAdFRxILTXTOpkTMojp+h JxYwEXBvzfEDJEkb32mget9VqzadfPzPCVefI6HHwg8Xh+4j0VicapHyUZbeNzyXG/hZGqD 3Uw4BlPcZRrt6um+uN50VlNHfv7L1c4xTL6ge4wkr6c76KenNpfQP5HfbxQkTOft+Hs3JwE P38+rP9LWE4 X-QQ-XMRINFO: NI4Ajvh11aEjEMj13RCX7UuhPEoou2bs1g== X-QQ-RECHKSPAM: 0 Content-Type: text/plain; charset="utf-8" The return value calculation was incorrect: `return len - buf_size;` Initially `len =3D buf_size`, then `len` decreases with each operation. This results in a negative return value on success. Fix by returning `buf_size - len` which correctly calculates the actual number of bytes written. Fixes: a976d790f494 ("efi/cper: Add a new helper function to print bitmasks= ") Signed-off-by: Morduan Zang --- drivers/firmware/efi/cper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c index 0232bd040f61..bd99802cb0ca 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -162,7 +162,7 @@ int cper_bits_to_str(char *buf, int buf_size, unsigned = long bits, len -=3D size; str +=3D size; } - return len - buf_size; + return buf_size - len; } EXPORT_SYMBOL_GPL(cper_bits_to_str); =20 --=20 2.50.1