tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/microcode head: 71da8a554f25713964a919311c324e5a32f08239 commit: 35da8ad78e9b1a25d95a281966c439da1ef9a98a [1/2] x86/microcode: Document the whole late loading problem reproduce: make htmldocs If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> Documentation/admin-guide/tainted-kernels.rst:143: WARNING: Block quote ends without a blank line; unexpected unindent. vim +143 Documentation/admin-guide/tainted-kernels.rst 896dd323abbf6a Thorsten Leemhuis 2019-01-08 111 896dd323abbf6a Thorsten Leemhuis 2019-01-08 112 0) ``G`` if all modules loaded have a GPL or compatible license, ``P`` if 337c188dff4a85 Mauro Carvalho Chehab 2016-11-07 113 any proprietary module has been loaded. Modules without a 337c188dff4a85 Mauro Carvalho Chehab 2016-11-07 114 MODULE_LICENSE or with a MODULE_LICENSE that is not recognised by 337c188dff4a85 Mauro Carvalho Chehab 2016-11-07 115 insmod as GPL compatible are assumed to be proprietary. 337c188dff4a85 Mauro Carvalho Chehab 2016-11-07 116 896dd323abbf6a Thorsten Leemhuis 2019-01-08 117 1) ``F`` if any module was force loaded by ``insmod -f``, ``' '`` if all 337c188dff4a85 Mauro Carvalho Chehab 2016-11-07 118 modules were loaded normally. 337c188dff4a85 Mauro Carvalho Chehab 2016-11-07 119 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 120 2) ``S`` if the kernel is running on a processor or system that is out of 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 121 specification: hardware has been put into an unsupported configuration, 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 122 therefore proper execution cannot be guaranteed. 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 123 Kernel will be tainted if, for example: 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 124 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 125 - on x86: PAE is forced through forcepae on intel CPUs (such as Pentium M) 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 126 which do not report PAE but may have a functional implementation, an SMP 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 127 kernel is running on non officially capable SMP Athlon CPUs, MSRs are 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 128 being poked at from userspace. 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 129 - on arm: kernel running on certain CPUs (such as Keystone 2) without 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 130 having certain kernel features enabled. 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 131 - on arm64: there are mismatched hardware features between CPUs, the 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 132 bootloader has booted CPUs in different modes. 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 133 - certain drivers are being used on non supported architectures (such as 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 134 scsi/snic on something else than x86_64, scsi/ips on non 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 135 x86/x86_64/itanium, have broken firmware settings for the 547f574fd9d5e3 Mathieu Chouquet-Stringer 2020-12-02 136 irqchip/irq-gic on arm64 ...). 35da8ad78e9b1a Ashok Raj 2022-08-13 137 - x86/x86_64: Microcode late loading is dangerous and will result in 35da8ad78e9b1a Ashok Raj 2022-08-13 138 tainting the kernel. It requires that all CPUs rendezvous to make sure 35da8ad78e9b1a Ashok Raj 2022-08-13 139 the update happens when the system is as quiescent as possible. However, 35da8ad78e9b1a Ashok Raj 2022-08-13 140 a higher priority MCE/SMI/NMI can move control flow away from that 35da8ad78e9b1a Ashok Raj 2022-08-13 141 rendezvous and interrupt the update, which can be detrimental to the 35da8ad78e9b1a Ashok Raj 2022-08-13 142 machine. 35da8ad78e9b1a Ashok Raj 2022-08-13 @143 e -- 0-DAY CI Kernel Test Service https://01.org/lkp
