From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 708915684 for ; Mon, 28 Apr 2025 02:02:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745805779; cv=none; b=TQcnycZU+ERFRhaZ4VQPczDg6AUU4LIytgY2yj8z5CHndl+R7LuyIvEoJLw1r78zRVbKaoHnVXEBAL+7/DMJFsLdbL+hLOWd361k9Jj/eQAHUk8g/DDKYgwLHsRj0vJGjLkfmp9gQOzQJb0XyaQjdJPwQnQ2pLFvVQjpju+huEo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745805779; c=relaxed/simple; bh=MopX525TCkQcHROpN7GoVWZdKANhbXQk4hSnGtc3nPw=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=jw7IU7mJvy7WTLIC999Dt1ks2aWrEMZgkwJb4/7ifdX+9LG6FAzgUc7FATP39VA4jJYNLVj6tb0UopwhaC6jNOgmsinFml/ySWcAdE0r2XtTsPF3EGXu0MCZaqrkmKZHWSJYjE00ipfBxQ5nPfh+fIfZtFRg0oBduTXhRBCfmjI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tweek.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=QFC8hkE9; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tweek.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="QFC8hkE9" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2ff8a2c7912so3118537a91.1 for ; Sun, 27 Apr 2025 19:02:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1745805777; x=1746410577; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:from:to:cc:subject:date:message-id:reply-to; bh=MopX525TCkQcHROpN7GoVWZdKANhbXQk4hSnGtc3nPw=; b=QFC8hkE9mjkqVcneJUoqYOPnaC11mePjBqFGtkYklczbGWoeYCEa9LrhhDEQZyv1u6 1oIGTLV2OUP4Ql0hx01DVCZh+OFsv8AUa6B39Y7ehukkAjUauVJeuc0T5Z73zn2pC2Y1 3+LBmMuVHEs9XyPYa+5WC9oa1IJC4/DM8lg1Pivk+aTXsGeOe9vgaryXlihp2DCAPhuu sr7aMFZq2c3wj3wlLB1ncGs1yzj/HY1U5ZLYPPFBrp1KOICS1jODYP3Xuw5Xfd+8NQGk IwGXLG28dD5gGdANkwxl/2xUKMFW8WV//1gpXE7+460xCOlzMZVQh88cOc4nCsLIwBW8 xB1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745805777; x=1746410577; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=MopX525TCkQcHROpN7GoVWZdKANhbXQk4hSnGtc3nPw=; b=wjQxfQEw5l71F20YnuwECW33UubBroz8pCmbCNfd2997l7Fk9ZHET2XgEn28jmUrDY SGJelvmBkNvrN4QwGw4b26Z4vua8VqGoD+zHsWrFBqXurwmfU+cYm4oOm56ErTSbhz5w bD3DT48HuPF4cH8T1nIAllfgQWXicnh+uOCmQmc0EBHHu+VM3oCHkg++Kif4ag6BgpDJ 2oMTQATGzARbLsfNsvi4zwm0WimRdns3Rkq+XjakGY8boAnLMO3TohrZi/VOB6SoxLGa xVAQ5/cDVQUl/MSzf58Xp4hb0Js5vktSbV5eolKTmRtZw13ghQ5pCJtb9ptcthtKHRHC YbLw== X-Gm-Message-State: AOJu0YxkCDA+Y07MxbUJZsuNUJgPHH1sT93GNCouVIu+MqpoPTFwVdqi rfCSBuQ+3hcS0fBCldsiPukFKQfCDP24RSrMUDXRia/5jgBRYJ7h0Kg6o8ed0/Vs+0Y7nyV4Gw= = X-Google-Smtp-Source: AGHT+IFfoiwCDkOFIvbjFMK+2SL2coc68INeilGDD1gRNw1HHbQBEamy/oazrklOQVaOxo7EbepwydsXgg== X-Received: from pjur4.prod.google.com ([2002:a17:90a:d404:b0:301:2679:9d9]) (user=tweek job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3c87:b0:2fa:17e4:b1cf with SMTP id 98e67ed59e1d1-309f895d396mr14658036a91.2.1745805777687; Sun, 27 Apr 2025 19:02:57 -0700 (PDT) Date: Mon, 28 Apr 2025 12:02:52 +1000 Precedence: bulk X-Mailing-List: linux-man@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.49.0.850.g28803427d3-goog Message-ID: <20250428020252.1569621-1-tweek@google.com> Subject: [PATCH v2] man/man2/memfd_secret.2: Update default state From: "=?UTF-8?q?Thi=C3=A9baud=20Weksteen?=" To: Alejandro Colomar Cc: linux-man@vger.kernel.org, Mike Rapoport , "=?UTF-8?q?Thi=C3=A9baud=20Weksteen?=" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable In commit b758fe6df50 ("mm/secretmem: make it on by default"), memfd_secret was updated to be enabled by default. Signed-off-by: Thi=C3=A9baud Weksteen --- Changes since v1: - Move the paragraph to the HISTORY section. - Drop reference to the performance concern. - Follow semantic newlines rule. man/man2/memfd_secret.2 | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/man/man2/memfd_secret.2 b/man/man2/memfd_secret.2 index 322d67a41..b3896b12d 100644 --- a/man/man2/memfd_secret.2 +++ b/man/man2/memfd_secret.2 @@ -136,6 +136,13 @@ or has not been enabled on the kernel command-line wit= h Linux. .SH HISTORY Linux 5.14. +.P +Before Linux 6.5, +.\" commit b758fe6df50daf68fef089d8f3c1cd49fc794ed2 +.BR memfd_secret () +was disabled by default and only available if the system +administrator turned it on using "secretmem.enable=3Dy" kernel +parameter. .SH NOTES The .BR memfd_secret () @@ -182,13 +189,6 @@ or spawn a new privileged user-space process to perfor= m secrets exfiltration using .BR ptrace (2). .P -The way -.BR memfd_secret () -allocates and locks the memory may impact overall system performance, -therefore the system call is disabled by default and only available -if the system administrator turned it on using -"secretmem.enable=3Dy" kernel parameter. -.P To prevent potential data leaks of memory regions backed by .BR memfd_secret () from a hybernation image, --=20 2.49.0.850.g28803427d3-goog