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| author | Fenghua Yu <fenghua.yu@intel.com> | 2021-03-22 13:53:25 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-03-28 22:52:16 +0200 |
| commit | ebca17707e38f2050b188d837bd4646b29a1b0c2 (patch) | |
| tree | 5302abc15def8faeb762187b66451dd25193e533 | |
| parent | ebb1064e7c2e90b56e4d40ab154ef9796060a1c3 (diff) | |
| download | lwn-ebca17707e38f2050b188d837bd4646b29a1b0c2.tar.gz lwn-ebca17707e38f2050b188d837bd4646b29a1b0c2.zip | |
Documentation/admin-guide: Change doc for split_lock_detect parameter
Since #DB for bus lock detect changes the split_lock_detect parameter,
update the documentation for the changes.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210322135325.682257-4-fenghua.yu@intel.com
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 04545725f187..aef927cec602 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5100,27 +5100,37 @@ spia_peddr= split_lock_detect= - [X86] Enable split lock detection + [X86] Enable split lock detection or bus lock detection When enabled (and if hardware support is present), atomic instructions that access data across cache line - boundaries will result in an alignment check exception. + boundaries will result in an alignment check exception + for split lock detection or a debug exception for + bus lock detection. off - not enabled - warn - the kernel will emit rate limited warnings + warn - the kernel will emit rate-limited warnings about applications triggering the #AC - exception. This mode is the default on CPUs - that supports split lock detection. + exception or the #DB exception. This mode is + the default on CPUs that support split lock + detection or bus lock detection. Default + behavior is by #AC if both features are + enabled in hardware. fatal - the kernel will send SIGBUS to applications - that trigger the #AC exception. + that trigger the #AC exception or the #DB + exception. Default behavior is by #AC if + both features are enabled in hardware. If an #AC exception is hit in the kernel or in firmware (i.e. not while executing in user mode) the kernel will oops in either "warn" or "fatal" mode. + #DB exception for bus lock is triggered only when + CPL > 0. + srbds= [X86,INTEL] Control the Special Register Buffer Data Sampling (SRBDS) mitigation. |