diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 119 |
1 files changed, 97 insertions, 22 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 7737ab5d04b2..d9c171ce4190 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -649,6 +649,13 @@ /proc/<pid>/coredump_filter. See also Documentation/filesystems/proc.txt. + coresight_cpu_debug.enable + [ARM,ARM64] + Format: <bool> + Enable/disable the CPU sampling based debugging. + 0: default value, disable debugging + 1: enable debugging at boot time + cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system @@ -720,7 +727,8 @@ See also Documentation/input/joystick-parport.txt ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot - time. See Documentation/dynamic-debug-howto.txt for + time. See + Documentation/admin-guide/dynamic-debug-howto.rst for details. Deprecated, see dyndbg. debug [KNL] Enable kernel debugging (events log level). @@ -883,7 +891,8 @@ dyndbg[="val"] [KNL,DYNAMIC_DEBUG] module.dyndbg[="val"] Enable debug messages at boot time. See - Documentation/dynamic-debug-howto.txt for details. + Documentation/admin-guide/dynamic-debug-howto.rst + for details. nompx [X86] Disables Intel Memory Protection Extensions. See Documentation/x86/intel_mpx.txt for more @@ -954,6 +963,12 @@ must already be setup and configured. Options are not yet supported. + owl,<addr> + Start an early, polled-mode console on a serial port + of an Actions Semi SoC, such as S500 or S900, at the + specified address. The serial port must already be + setup and configured. Options are not yet supported. + smh Use ARM semihosting calls for early console. s3c2410,<addr> @@ -1486,12 +1501,21 @@ in crypto/hash_info.h. ima_policy= [IMA] - The builtin measurement policy to load during IMA - setup. Specyfing "tcb" as the value, measures all - programs exec'd, files mmap'd for exec, and all files - opened with the read mode bit set by either the - effective uid (euid=0) or uid=0. - Format: "tcb" + The builtin policies to load during IMA setup. + Format: "tcb | appraise_tcb | secure_boot" + + The "tcb" policy measures all programs exec'd, files + mmap'd for exec, and all files opened with the read + mode bit set by either the effective uid (euid=0) or + uid=0. + + The "appraise_tcb" policy appraises the integrity of + all files owned by root. (This is the equivalent + of ima_appraise_tcb.) + + The "secure_boot" policy appraises the integrity + of files (eg. kexec kernel image, kernel modules, + firmware, policy, etc) based on file signatures. ima_tcb [IMA] Deprecated. Use ima_policy= instead. Load a policy which meets the needs of the Trusted @@ -1838,6 +1862,18 @@ for all guests. Default is 1 (enabled) if in 64-bit or 32-bit PAE mode. + kvm-arm.vgic_v3_group0_trap= + [KVM,ARM] Trap guest accesses to GICv3 group-0 + system registers + + kvm-arm.vgic_v3_group1_trap= + [KVM,ARM] Trap guest accesses to GICv3 group-1 + system registers + + kvm-arm.vgic_v3_common_trap= + [KVM,ARM] Trap guest accesses to GICv3 common + system registers + kvm-intel.ept= [KVM,Intel] Disable extended page tables (virtualized MMU) support on capable Intel chips. Default is 1 (enabled) @@ -2136,6 +2172,12 @@ memmap=nn[KMG]@ss[KMG] [KNL] Force usage of a specific region of memory. Region of memory to be used is from ss to ss+nn. + If @ss[KMG] is omitted, it is equivalent to mem=nn[KMG], + which limits max address to nn[KMG]. + Multiple different regions can be specified, + comma delimited. + Example: + memmap=100M@2G,100M#3G,1G!1024G memmap=nn[KMG]#ss[KMG] [KNL,ACPI] Mark specific memory as ACPI data. @@ -2148,6 +2190,9 @@ memmap=64K$0x18690000 or memmap=0x10000$0x18690000 + Some bootloaders may need an escape character before '$', + like Grub2, otherwise '$' and the following number + will be eaten. memmap=nn[KMG]!ss[KMG] [KNL,X86] Mark specific memory as protected. @@ -2270,8 +2315,11 @@ that the amount of memory usable for all allocations is not too small. - movable_node [KNL] Boot-time switch to enable the effects - of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details. + movable_node [KNL] Boot-time switch to make hotplugable memory + NUMA nodes to be movable. This means that the memory + of such nodes will be usable only for movable + allocations which rules out almost all kernel + allocations. Use with caution! MTD_Partition= [MTD] Format: <name>,<region-number>,<size>,<offset> @@ -3238,21 +3286,17 @@ rcutree.gp_cleanup_delay= [KNL] Set the number of jiffies to delay each step of - RCU grace-period cleanup. This only has effect - when CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP is set. + RCU grace-period cleanup. rcutree.gp_init_delay= [KNL] Set the number of jiffies to delay each step of - RCU grace-period initialization. This only has - effect when CONFIG_RCU_TORTURE_TEST_SLOW_INIT - is set. + RCU grace-period initialization. rcutree.gp_preinit_delay= [KNL] Set the number of jiffies to delay each step of RCU grace-period pre-initialization, that is, the propagation of recent CPU-hotplug changes up - the rcu_node combining tree. This only has effect - when CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT is set. + the rcu_node combining tree. rcutree.rcu_fanout_exact= [KNL] Disable autobalancing of the rcu_node combining @@ -3328,6 +3372,17 @@ This wake_up() will be accompanied by a WARN_ONCE() splat and an ftrace_dump(). + rcuperf.gp_async= [KNL] + Measure performance of asynchronous + grace-period primitives such as call_rcu(). + + rcuperf.gp_async_max= [KNL] + Specify the maximum number of outstanding + callbacks per writer thread. When a writer + thread exceeds this limit, it invokes the + corresponding flavor of rcu_barrier() to allow + previously posted callbacks to drain. + rcuperf.gp_exp= [KNL] Measure performance of expedited synchronous grace-period primitives. @@ -3355,17 +3410,22 @@ rcuperf.perf_runnable= [BOOT] Start rcuperf running at boot time. + rcuperf.perf_type= [KNL] + Specify the RCU implementation to test. + rcuperf.shutdown= [KNL] Shut the system down after performance tests complete. This is useful for hands-off automated testing. - rcuperf.perf_type= [KNL] - Specify the RCU implementation to test. - rcuperf.verbose= [KNL] Enable additional printk() statements. + rcuperf.writer_holdoff= [KNL] + Write-side holdoff between grace periods, + in microseconds. The default of zero says + no holdoff. + rcutorture.cbflood_inter_holdoff= [KNL] Set holdoff time (jiffies) between successive callback-flood tests. @@ -3715,8 +3775,14 @@ slab_nomerge [MM] Disable merging of slabs with similar size. May be necessary if there is some reason to distinguish - allocs to different slabs. Debug options disable - merging on their own. + allocs to different slabs, especially in hardened + environments where the risk of heap overflows and + layout control by attackers can usually be + frustrated by disabling merging. This will reduce + most of the exposure of a heap attack to a single + cache (risks via metadata attacks are mostly + unchanged). Debug options disable merging on their + own. For more information see Documentation/vm/slub.txt. slab_max_order= [MM, SLAB] @@ -3803,6 +3869,15 @@ spia_pedr= spia_peddr= + srcutree.counter_wrap_check [KNL] + Specifies how frequently to check for + grace-period sequence counter wrap for the + srcu_data structure's ->srcu_gp_seq_needed field. + The greater the number of bits set in this kernel + parameter, the less frequently counter wrap will + be checked for. Note that the bottom two bits + are ignored. + srcutree.exp_holdoff [KNL] Specifies how many nanoseconds must elapse since the end of the last SRCU grace period for |