From nobody Sun Feb 8 08:27:48 2026 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 DEB3A31DDAB for ; Mon, 22 Dec 2025 15:00:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766415636; cv=none; b=diii16lExnUpXN5BKMj/N3CzV2mJzjGcnQu4tzJocIB0DnSPq8TCD/7ZAIVFDmlot3bCivkEHtAAK6uVa4Y2jNBLYp3AfRkgPEnwVgQ1E0HGwGPZ65jI+vXLjmWnjAsYxWgigLng8Mdpr4F31yf5BUocoxCxP/cE7BBP8OGxY/0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766415636; c=relaxed/simple; bh=iUx/KzxTUqm5OvRtocF/z3yRrTFJTMONFUZOZ5wDo1Q=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=lbVxbCcvazpApSsRQRU5UdtwsZIZ/cQZb4kqa52uvYG36AiiwaLwKQlFiuvcQvTfd3AVGnS4I345WjRXdlVOeiomTNoMk48Ksf0r63qUnMSGXp1pFcfAtDPWEM6GSiwf0vm3sMZpKPctW7gPoaiv/vBKSno//RN2BomzptN6pP4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--elver.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=bWiTdyOB; arc=none smtp.client-ip=209.85.128.74 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--elver.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bWiTdyOB" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-47788165c97so22905225e9.0 for ; Mon, 22 Dec 2025 07:00:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1766415633; x=1767020433; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=SLecpNCzVXawwP8cx0xrGTVH2kk35JOIvedfHtD8OOw=; b=bWiTdyOBzFxFWE50RsjylX8A3WvRDdYC4UNHQYT+NU0bae+yDFt7Twd5Cpj76pzFtw SFquMiuRDXZLpjQ7YypYXYTd55E/wbeMBgV2HDjjmU62Xsfal/FcKvHz7MS1pwXueIDw uLWkuYdrMKTOz1KjGK3l5DRSUKKCcXl20TV0ugXsT9lKN+M4k8xIVxtp219K0x0GDkqW GaHjPl4EjbxH8iAmlTJ8WDYyfxS+Dda6CBr+DW79m/FVn6xUXR/GIYuoZXHht/OuThky 77OvxkH8xXnPmsrWCuqYRx7Y8zA9omgx4th9uKMXBgcCGPv3+ZV7QAiABnnNozCqQdjG 2Mvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1766415633; x=1767020433; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=SLecpNCzVXawwP8cx0xrGTVH2kk35JOIvedfHtD8OOw=; b=E4NTzHUiPRBSdMbPM8oht2Ug09a8yDKRMM+pmi1ldKayLK4ArIgIYth3zWTkK1tifp CV0uVvORNzDq/bRQ/FuEBzueCjn9yhnllv5vxMskiIEHZPJJOl2OKwnEjeXysn/UV6U6 9S5aMStPNfqjUIjF4L+0oUR4F1xHkvcWKlg4x29z13Stp2WmQ79crrGsPKOj8dpxbn0y 362DCI0BjgNowoOj2Wqs5QOySOw7TJr2M5VvkJKVUzv2e0TYHKjnaxVwgtJ0VphQeXBb hwvlIeHBE80IBrXD6pewoZoU4Ya+L+LsAYlftduyvfinWhFpW//UK+jqqplN9qkphG1+ QxzQ== X-Forwarded-Encrypted: i=1; AJvYcCUpB/05v4TYGwl+RMsDPXV0QRafaOH10Acv5t7RbUXDuKZ3I7oFKIysVBAVYqobtW+oXKOsEHOqTb7ZHbQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yw/X92CHIc/jStUyBEfToMHpcq+stcuK5qMMkZStiZzn5MNLK1v 0hfolhvCep+wWWFDubUWBX44BnnP8vrbbuyH3SWYddpIbQ12q2gDz+QZYWWu+iptoGKYO9215/E 4kA== X-Google-Smtp-Source: AGHT+IGrVe5BwxTN1xBcqifymYkOlLo7MfVSee5M8PugpQUe7fIfSUpxJR3UYaitoT+KLjV38czMFVaTBA== X-Received: from wmco23.prod.google.com ([2002:a05:600c:a317:b0:477:93dd:bbb1]) (user=elver job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:46c4:b0:477:7bd2:693f with SMTP id 5b1f17b1804b1-47d1953b80bmr128913385e9.6.1766415633343; Mon, 22 Dec 2025 07:00:33 -0800 (PST) Date: Mon, 22 Dec 2025 16:00:06 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.52.0.322.g1dd061c0dc-goog Message-ID: <20251222150018.1349672-1-elver@google.com> Subject: [PATCH] docs: kernel-parameters: add kfence parameters From: Marco Elver To: elver@google.com, Andrew Morton Cc: Alexander Potapenko , Dmitry Vyukov , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kasan-dev@googlegroups.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a brief summary for KFENCE's kernel command-line parameters in admin-guide/kernel-parameters. Signed-off-by: Marco Elver --- .../admin-guide/kernel-parameters.txt | 35 +++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index a8d0afde7f85..1058f2a6d6a8 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2917,6 +2917,41 @@ Kernel parameters for Movable pages. "nn[KMGTPE]", "nn%", and "mirror" are exclusive, so you cannot specify multiple forms. =20 + kfence.burst=3D [MM,KFENCE] The number of additional successive + allocations to be attempted through KFENCE for each + sample interval. + Format: + Default: 0 + + kfence.check_on_panic=3D + [MM,KFENCE] Whether to check all KFENCE-managed objects' + canaries on panic. + Format: + Default: false + + kfence.deferrable=3D + [MM,KFENCE] Whether to use a deferrable timer to trigger + allocations. This avoids forcing CPU wake-ups if the + system is idle, at the risk of a less predictable + sample interval. + Format: + Default: CONFIG_KFENCE_DEFERRABLE + + kfence.sample_interval=3D + [MM,KFENCE] KFENCE's sample interval in milliseconds. + Format: + 0 - Disable KFENCE. + >0 - Enabled KFENCE with given sample interval. + Default: CONFIG_KFENCE_SAMPLE_INTERVAL + + kfence.skip_covered_thresh=3D + [MM,KFENCE] If pool utilization reaches this threshold + (pool usage%), KFENCE limits currently covered + allocations of the same source from further filling + up the pool. + Format: + Default: 75 + kgdbdbgp=3D [KGDB,HW,EARLY] kgdb over EHCI usb debug port. Format: [,poll interval] The controller # is the number of the ehci usb debug --=20 2.52.0.322.g1dd061c0dc-goog