The following commit has been merged into the x86/core branch of tip:
Commit-ID: 24452d9ef17502965021ce5df30f4e184245a5ac
Gitweb: https://git.kernel.org/tip/24452d9ef17502965021ce5df30f4e184245a5ac
Author: Kees Cook <kees@kernel.org>
AuthorDate: Wed, 03 Sep 2025 20:46:42 -07:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 04 Sep 2025 21:59:08 +02:00
x86/cfi: Document the "cfi=" bootparam options
The kernel-parameters.txt didn't have a section for the cfi= options.
Add it.
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250904034656.3670313-3-kees@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 747a55a..8bbffbb 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: