From: Kees Cook <kees@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <kees@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
"Paul E. McKenney" <paulmck@kernel.org>,
Randy Dunlap <rdunlap@infradead.org>,
linux-doc@vger.kernel.org, Nathan Chancellor <nathan@kernel.org>,
Vegard Nossum <vegard.nossum@oracle.com>,
Miguel Ojeda <ojeda@kernel.org>,
Linus Walleij <linus.walleij@linaro.org>,
Jeff Johnson <jeff.johnson@oss.qualcomm.com>,
David Woodhouse <dwmw2@infradead.org>,
"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Marco Elver <elver@google.com>,
Przemek Kitszel <przemyslaw.kitszel@intel.com>,
Ramon de C Valle <rcvalle@google.com>,
Nicolas Schier <nicolas.schier@linux.dev>,
Masahiro Yamada <masahiroy@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
Sami Tolvanen <samitolvanen@google.com>,
Mark Rutland <mark.rutland@arm.com>,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
linux-kbuild@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, x86@kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH v2 3/9] x86/cfi: Document the "cfi=" bootparam options
Date: Wed, 3 Sep 2025 20:46:42 -0700 [thread overview]
Message-ID: <20250904034656.3670313-3-kees@kernel.org> (raw)
In-Reply-To: <20250904033217.it.414-kees@kernel.org>
The kernel-parameters.txt didn't have a section for the cfi= options.
Add it.
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <linux-doc@vger.kernel.org>
---
Documentation/admin-guide/kernel-parameters.txt | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 747a55abf494..8bbffbb334ab 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -608,6 +608,23 @@
ccw_timeout_log [S390]
See Documentation/arch/s390/common_io.rst for details.
+ cfi= [X86-64] Set Control Flow Integrity checking features
+ when CONFIG_FINEIBT is enabled.
+ Format: feature[,feature...]
+ Default: auto
+
+ auto: Use FineIBT if IBT available, otherwise kCFI.
+ Under FineIBT, enable "paranoid" mode when
+ FRED is not available.
+ off: Turn off CFI checking.
+ kcfi: Use kCFI (disable FineIBT).
+ fineibt: Use FineIBT (even if IBT not available).
+ norand: Do not re-randomize CFI hashes.
+ paranoid: Add caller hash checking under FineIBT.
+ bhi: Enable register poisoning to stop speculation
+ across FineIBT. (Disabled by default.)
+ warn: Do not enforce CFI checking: warn only.
+
cgroup_disable= [KNL] Disable a particular controller or optional feature
Format: {name of the controller(s) or feature(s) to disable}
The effects of cgroup_disable=foo are:
--
2.34.1
next prev parent reply other threads:[~2025-09-04 3:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-04 3:46 [PATCH v2 0/9] kcfi: Prepare for GCC support Kees Cook
2025-09-04 3:46 ` [PATCH v2 1/9] compiler_types.h: Move __nocfi out of compiler-specific header Kees Cook
2025-09-04 18:28 ` Nathan Chancellor
2025-09-04 3:46 ` [PATCH v2 2/9] x86/traps: Clarify KCFI instruction layout Kees Cook
2025-09-04 3:46 ` Kees Cook [this message]
2025-09-04 18:32 ` [PATCH v2 3/9] x86/cfi: Document the "cfi=" bootparam options Nathan Chancellor
2025-09-04 3:46 ` [PATCH v2 4/9] x86/cfi: Standardize on common "CFI:" prefix for CFI reports Kees Cook
2025-09-04 18:40 ` Nathan Chancellor
2025-09-05 0:40 ` Kees Cook
2025-09-04 3:46 ` [PATCH v2 5/9] x86/cfi: Add "debug" option to "cfi=" bootparam Kees Cook
2025-09-04 7:00 ` Peter Zijlstra
2025-09-04 3:46 ` [PATCH v2 6/9] x86/cfi: Remove __noinitretpoline and __noretpoline Kees Cook
2025-09-04 3:46 ` [PATCH v2 7/9] kconfig: Add transitional symbol attribute for migration support Kees Cook
2025-09-04 3:46 ` [PATCH v2 8/9] kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI Kees Cook
2025-09-04 3:46 ` [PATCH v2 9/9] ARM: traps: Implement KCFI trap handler for ARM32 Kees Cook
2025-09-04 7:04 ` [PATCH v2 0/9] kcfi: Prepare for GCC support Peter Zijlstra
2025-09-04 16:37 ` Kees Cook
2025-09-04 20:01 ` Peter Zijlstra
2025-09-05 0:42 ` Kees Cook
2025-09-05 7:44 ` Miguel Ojeda
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