kernel.git/arch/s390/kernel/setup.c, branch linux-4.16.y

s390: correct nospec auto detection init order

2018-05-25T14:46:07Z

[ Upstream commit 6a3d1e81a434fc311f224b8be77258bafc18ccc6 ] With CONFIG_EXPOLINE_AUTO=y the call of spectre_v2_auto_early() via early_initcall is done *after* the early_param functions. This overwrites any settings done with the nobp/no_spectre_v2/spectre_v2 parameters. The code patching for the kernel is done after the evaluation of the early parameters but before the early_initcall is done. The end result is a kernel image that is patched correctly but the kernel modules are not. Make sure that the nospec auto detection function is called before the early parameters are evaluated and before the code patching is done. Fixes: 6e179d64126b ("s390: add automatic detection of the spectre defense") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390: add support for IBM z14 Model ZR1

2018-04-24T07:43:08Z

commit 451239eb3d397bd197a79cc3aab943da41ba0905 upstream. Just add the new machine type number to the two places that matter. Cc: # v4.14+ Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390: introduce execute-trampolines for branches

2018-02-07T14:57:02Z

Add CONFIG_EXPOLINE to enable the use of the new -mindirect-branch= and -mfunction_return= compiler options to create a kernel fortified against the specte v2 attack. With CONFIG_EXPOLINE=y all indirect branches will be issued with an execute type instruction. For z10 or newer the EXRL instruction will be used, for older machines the EX instruction. The typical indirect call basr %r14,%r1 is replaced with a PC relative call to a new thunk brasl %r14,__s390x_indirect_jump_r1 The thunk contains the EXRL/EX instruction to the indirect branch __s390x_indirect_jump_r1: exrl 0,0f j . 0: br %r1 The detour via the execute type instruction has a performance impact. To get rid of the detour the new kernel parameter "nospectre_v2" and "spectre_v2=[on,off,auto]" can be used. If the parameter is specified the kernel and module code will be patched at runtime. Signed-off-by: Martin Schwidefsky

s390/alternative: use a copy of the facility bit mask

2018-02-05T12:49:16Z

To be able to switch off specific CPU alternatives with kernel parameters make a copy of the facility bit mask provided by STFLE and use the copy for the decision to apply an alternative. Reviewed-by: David Hildenbrand Reviewed-by: Cornelia Huck Signed-off-by: Martin Schwidefsky

s390: kernel: add SPDX identifiers to the remaining files

2017-11-24T14:37:12Z

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the arch/s390/kernel/ files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Signed-off-by: Martin Schwidefsky

s390: simplify transactional execution elf hwcap handling

2017-11-09T15:54:30Z

Just use MACHINE_HAS_TE to decide if HWCAP_S390_TE needs to be added to elf_hwcap. Suggested-by: Dan Horák Reviewed-by: Christian Borntraeger Reviewed-by: Hendrik Brueckner Signed-off-by: Heiko Carstens

s390/virtio: remove unused header file kvm_virtio.h

2017-11-09T14:54:07Z

With commit 7fb2b2d51244 ("s390/virtio: remove the old KVM virtio transport") the pre-ccw virtio transport for s390 was removed. To complete the removal the uapi header file that contains the related data structures must also be removed. Signed-off-by: Christian Borntraeger Signed-off-by: Heiko Carstens

s390/nmi: allocation of the extended save area

2017-10-19T15:07:39Z

The machine check extended save area is needed to store the vector registers and the guarded storage control block when a CPU is interrupted by a machine check. Move the slab cache allocation of the full save area to nmi.c, for early boot use a static __initdata block. Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/vdso: move boot_vdso_data to vdso.c

2017-10-18T12:11:36Z

The boot_vdso_data variable is related to the vdso code, the magic of the initial vdso area for the early boot and the replacement of it in vdso_init should all be put into vdso.c. Signed-off-by: Martin Schwidefsky

s390: introduce CPU alternatives

2017-10-18T12:11:29Z

Implement CPU alternatives, which allows to optionally patch newer instructions at runtime, based on CPU facilities availability. A new kernel boot parameter "noaltinstr" disables patching. Current implementation is derived from x86 alternatives. Although ideal instructions padding (when altinstr is longer then oldinstr) is added at compile time, and no oldinstr nops optimization has to be done at runtime. Also couple of compile time sanity checks are done: 1. oldinstr and altinstr must be <= 254 bytes long, 2. oldinstr and altinstr must not have an odd length. alternative(oldinstr, altinstr, facility); alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2); Both compile time and runtime padding consists of either 6/4/2 bytes nop or a jump (brcl) + 2 bytes nop filler if padding is longer then 6 bytes. .altinstructions and .altinstr_replacement sections are part of __init_begin : __init_end region and are freed after initialization. Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky