From nobody Mon Jun 8 17:38:08 2026 Received: from mail-wm1-f45.google.com (mail-wm1-f45.google.com [209.85.128.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B07944B662 for ; Wed, 27 May 2026 18:16:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.45 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779905764; cv=none; b=q2bBKSO5aknktW8bDBxiaV85BwfilFSNSjWF5/RiTSHwtMxhzBnZz3sulqftFRymsdE39ShHuI7OuM3j/hjtJIwmLNBptuUqYzIP9RsMCKt7DZEiSHpxPNFuxMykkFWowWkKFeErankjbQNgpE14EU2aaQVhWRXs+mInBYSv+OU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779905764; c=relaxed/simple; bh=2O98pcDodvf/w5L1Uqu7/tQOCDHAp85xEdv7VYL7Blk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=npTR/hje+eeCQV3VbagN/dhPsny+qLMs1tGCtFb4K857F0ZAhzvKvW+n3/9tsQkn1hvrlP73pRL3uimSnUtU8229VWKNPRb6wFJOcQFEhmCwF1gLUdtnK25wQ0Hli9REk2ASt5bJK6vO+S8+uWtCHlaqCmKgy8Xi16fmLEW4ChU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=PvYo2mqs; arc=none smtp.client-ip=209.85.128.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PvYo2mqs" Received: by mail-wm1-f45.google.com with SMTP id 5b1f17b1804b1-4903f7a90d1so50030685e9.2 for ; Wed, 27 May 2026 11:16:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1779905761; x=1780510561; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=cc56agp3MwuW21VE5gH+ln5C8u11biR7qsKK3i4wPsw=; b=PvYo2mqs/wh7+Gtx9zjLfbJ4dAsqBIAiMC3it/PnYlA43003rlAxkgsoUSSiqYBXYb 2FXd3+RiHxISB1a5AqebJd4dzH23POSbtKcMfO5uM0RJkmrfCUrt45bHhMGOIBKEJkEy 09Xpvo/aEl58LcbawVEmTwyLZiQl0rVHYGWQRUA6E0qQIIFSB+xQx4OO7Iq3x6w7lNU2 AIgerfSXKE8SdoA3AsFAPs6BB7J4cZR8H8MQvQ/ux94QNRzjg3ebCvjftV3mRdIzHj5s Dq20M4+dsLveoMCOlnXx0QVNJmPuju5OUjTjUc+hg7fd0bD41gRIerw0Q928iJ65jGEv rzTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779905761; x=1780510561; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=cc56agp3MwuW21VE5gH+ln5C8u11biR7qsKK3i4wPsw=; b=K3PMkYuzuwXLcaMsGGIJq2enTgG2lR1fnfwgo6ToHxfC8DBFF0CspA/D1eBzXkilWQ KNJPyp5iXI+9T7DV6jNyN9qSghI/AnMp8tgbMMEzOg4ZNG8dkFuf3TLLojjh244fQMrC 1IetAWteTBjCyJWYSKIVERnv1c9oPUsLkXQn5TPUcv6no/6EKFRHsdNDJqRsMC3eD68n 8HMkp7D6KihjzdKpb5NGLqF32GTfZ7jFr010526FX74jxmPgspit09hEuXCHEG353xBN ZfgpuolVuYm8fkbSMOXCzqyjoJ801or4PzCgZRjnIgzxi7LjV/UcjmAkMjLq+ggHatLM PQPA== X-Forwarded-Encrypted: i=1; AFNElJ+UUWdqJCcUAOG73qr0Bchwy4zTKKBvuACRAxJEI04znPcC2h6M9f70Xg8Ymn1IVMLwPmGV31u4Z16toPU=@vger.kernel.org X-Gm-Message-State: AOJu0YwwnuaDxzTKQo3vctKkRTzNhD9vr8gamxGFDk5AK6qyEbXomROW D4c39TkFPDlXA3Cc00S7q/3Xxxsm+9npt0fmwQWkRXRSYhphE5qc9gbjj7wJDw== X-Gm-Gg: Acq92OGiJ/G4hBQxEjUVBikCWLFQ/7nLhurQiQruyGh+8JOqCceRH8SRQIlACZ2Q6wC ovXR6kabsTbIpo3cw3iig3+O/wld7+P1iyzCTmFlPMKchMOJpILtufU68zNGm2b2StVvsrUTymM +b9pI5tqw9jq/PcbAHIGS5sJc2KUqGb3M9zd+HHXV/3ohzgNsH0xlZPBekbc9N+5X5daKRMFBKb 71o06UnEoEiHSbORRmbD31wgcEjl1B3y/htOmPQU1mAnNV6FI2KWqCzz6XHkqNDfsdASQ8Kxs5C sdnspjWEFCV4nbXI5UHk7rHd3VAMoe9Vs0yhCYO1NSvg5FsJe1xHhv7MsdkEqkwFeWfteQXHi/Y HJnX6hdkoVZSdU/S0CtqaibTdcUl6Cv/6XysIp+YXFr9aDf72ut8E9p66ViG6uH2Otra4W9q9L6 KJ0E34Y6IaR8SQTG6K0C3/v3z6id685g== X-Received: by 2002:a05:600c:35c8:b0:490:44eb:c1e7 with SMTP id 5b1f17b1804b1-49044ebc2d5mr442432465e9.30.1779905760422; Wed, 27 May 2026 11:16:00 -0700 (PDT) Received: from localhost ([212.73.77.104]) by smtp.gmail.com with UTF8SMTPSA id 5b1f17b1804b1-4904526c926sm736405855e9.1.2026.05.27.11.15.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 27 May 2026 11:15:59 -0700 (PDT) From: Askar Safin To: Alejandro Colomar , linux-man@vger.kernel.org Cc: Christian Brauner , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] man/man3/errno.3: clarify ENOTSUP and EOPNOTSUPP Date: Wed, 27 May 2026 18:15:48 +0000 Message-ID: <20260527181549.2237547-1-safinaskar@gmail.com> X-Mailer: git-send-email 2.47.3 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 Content-Type: text/plain; charset="utf-8" As revealed by Christian Brauner recently ( https://lore.kernel.org/all/20260527-fotowettbewerb-abwinken-einfach-83db= 3411945b@brauner/ ), EOPNOTSUPP is widely used on Linux to mean "Operation not supported", as opposed to "Operation not supported on socket". Also, as seen in POSIX issue 8: https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/errno.h.html POSIX doesn't require ENOTSUP and EOPNOTSUPP to be distinct, so let's update that, too. Signed-off-by: Askar Safin --- man/man3/errno.3 | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/man/man3/errno.3 b/man/man3/errno.3 index a070dab..fdd2710 100644 --- a/man/man3/errno.3 +++ b/man/man3/errno.3 @@ -477,13 +477,14 @@ Name not unique on network. No such device or address (POSIX.1-2001). .TP .B EOPNOTSUPP -Operation not supported on socket (POSIX.1-2001). +Operation not supported (POSIX.1-2001). +According to POSIX.1 this is "Operation not supported on socket", +but on Linux it effectively means just "Operation not supported". .IP .RB ( ENOTSUP and .B EOPNOTSUPP -have the same value on Linux, but -according to POSIX.1 these error values should be distinct.) +have the same value on Linux.) .TP .B EOVERFLOW Value too large to be stored in data type (POSIX.1-2001). base-commit: 9a4bfd0e50745c2649b6291db40b58e37c9c1c6b --=20 2.47.3