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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt48
1 files changed, 37 insertions, 11 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1666576acc0e..9cd9cd06538b 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -446,6 +446,9 @@
arm64.nobti [ARM64] Unconditionally disable Branch Target
Identification support
+ arm64.nogcs [ARM64] Unconditionally disable Guarded Control Stack
+ support
+
arm64.nomops [ARM64] Unconditionally disable Memory Copy and Memory
Set instructions support
@@ -918,12 +921,16 @@
the parameter has no effect.
crash_kexec_post_notifiers
- Run kdump after running panic-notifiers and dumping
- kmsg. This only for the users who doubt kdump always
- succeeds in any situation.
- Note that this also increases risks of kdump failure,
- because some panic notifiers can make the crashed
- kernel more unstable.
+ Only jump to kdump kernel after running the panic
+ notifiers and dumping kmsg. This option increases
+ the risks of a kdump failure, since some panic
+ notifiers can make the crashed kernel more unstable.
+ In configurations where kdump may not be reliable,
+ running the panic notifiers could allow collecting
+ more data on dmesg, like stack traces from other CPUS
+ or extra data dumped by panic_print. Note that some
+ configurations enable this option unconditionally,
+ like Hyper-V, PowerPC (fadump) and AMD SEV-SNP.
crashkernel=size[KMG][@offset[KMG]]
[KNL,EARLY] Using kexec, Linux can switch to a 'crash kernel'
@@ -1546,6 +1553,7 @@
failslab=
fail_usercopy=
fail_page_alloc=
+ fail_skb_realloc=
fail_make_request=[KNL]
General fault injection mechanism.
Format: <interval>,<probability>,<space>,<times>
@@ -5412,11 +5420,6 @@
Set time (jiffies) between CPU-hotplug operations,
or zero to disable CPU-hotplug testing.
- rcutorture.read_exit= [KNL]
- Set the number of read-then-exit kthreads used
- to test the interaction of RCU updaters and
- task-exit processing.
-
rcutorture.read_exit_burst= [KNL]
The number of times in a given read-then-exit
episode that a set of read-then-exit kthreads
@@ -5426,6 +5429,14 @@
The delay, in seconds, between successive
read-then-exit testing episodes.
+ rcutorture.reader_flavor= [KNL]
+ A bit mask indicating which readers to use.
+ If there is more than one bit set, the readers
+ are entered from low-order bit up, and are
+ exited in the opposite order. For SRCU, the
+ 0x1 bit is normal readers, 0x2 NMI-safe readers,
+ and 0x4 light-weight readers.
+
rcutorture.shuffle_interval= [KNL]
Set task-shuffle interval (s). Shuffling tasks
allows some CPUs to go into dyntick-idle mode
@@ -6727,6 +6738,15 @@
torture.verbose_sleep_duration= [KNL]
Duration of each verbose-printk() sleep in jiffies.
+ tpm.disable_pcr_integrity= [HW,TPM]
+ Do not protect PCR registers from unintended physical
+ access, or interposers in the bus by the means of
+ having an integrity protected session wrapped around
+ TPM2_PCR_Extend command. Consider this in a situation
+ where TPM is heavily utilized by IMA, thus protection
+ causing a major performance hit, and the space where
+ machines are deployed is by other means guarded.
+
tpm_suspend_pcr=[HW,TPM]
Format: integer pcr id
Specify that at suspend time, the tpm driver
@@ -6867,6 +6887,12 @@
reserve_mem=12M:4096:trace trace_instance=boot_map^traceoff^traceprintk@trace,sched,irq
+ Note, saving the trace buffer across reboots does require that the system
+ is set up to not wipe memory. For instance, CONFIG_RESET_ATTACK_MITIGATION
+ can force a memory reset on boot which will clear any trace that was stored.
+ This is just one of many ways that can clear memory. Make sure your system
+ keeps the content of memory across reboots before relying on this option.
+
See also Documentation/trace/debugging.rst