linux-dev/drivers/s390/char/Makefile, branch master

drivers/s390/char: Add Ultravisor io device

2022-05-20T14:38:35Z

This patch adds a new miscdevice to expose some Ultravisor functions to userspace. Userspace can send IOCTLs to the uvdevice that will then emit a corresponding Ultravisor Call and hands the result over to userspace. The uvdevice is available if the Ultravisor Call facility is present. Userspace can call the Retrieve Attestation Measurement Ultravisor Call using IOCTLs on the uvdevice. The uvdevice will do some sanity checks first. Then, copy the request data to kernel space, build the UVCB, perform the UV call, and copy the result back to userspace. Signed-off-by: Steffen Eiden Reviewed-by: Janosch Frank Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/kvm/20220516113335.338212-1-seiden@linux.ibm.com/ Message-Id: <20220516113335.338212-1-seiden@linux.ibm.com> Signed-off-by: Janosch Frank (whitespace and tristate fixes, pick)

s390/sclp: Add support for SCLP AP adapter config/deconfig

2020-10-07T19:50:00Z

Add support for AP bus adapter config and deconfig to the sclp core code. The code is statically build into the kernel when ZCRYPT is configured either as module or with static support. This is the base functionality for having configure/deconfigure support in the AP bus and card code. Another patch will exploit this soon. Signed-off-by: Harald Freudenberger Suggested-by: Pierre Morel Signed-off-by: Vasily Gorbik

s390: clean .bss before running uncompressed kernel

2019-08-21T10:58:52Z

Clean uncompressed kernel .bss section in the startup code before the uncompressed kernel is executed. At this point of time initrd and certificates have been already rescued. Uncompressed kernel .bss size is known from vmlinux_info. It is also taken into consideration during uncompressed kernel positioning by kaslr (so it is safe to clean it). With that uncompressed kernel is starting with .bss section zeroed and no .bss section usage restrictions apply. Which makes chkbss checks for uncompressed kernel objects obsolete and they can be removed. early_nobss.c is also not needed anymore. Parts of it which are still relevant are moved to early.c. Kasan initialization code is now called directly from head64 (early.c is instrumented and should not be executed before kasan shadow memory is set up). Reviewed-by: Philipp Rudo Signed-off-by: Vasily Gorbik

s390/sclp: remove call home support

2019-06-19T15:54:27Z

This feature has never been used, so remove it. Acked-by: Vasily Gorbik Acked-by: Hendrik Brueckner Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/kasan: avoid instrumentation of early C code

2018-10-09T09:21:17Z

Instrumented C code cannot run without the kasan shadow area. Exempt source code files from kasan which are running before / used during kasan initialization. Reviewed-by: Martin Schwidefsky Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390/decompressor: avoid reusing uncompressed image objects

2018-06-25T08:14:39Z

Re-compile ebcdic.c and sclp_early_core.c for the decompressor, using proper decompressor CFLAGS. This also allows to potentially use instrumentation for those files when built for the main kernel image. With kbuild there is no easy way to re-compile a source file from another directory. Bypass ugly rules and Makefile meta-programming with relative path includes of original files. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390: introduce compile time check for empty .bss section

2018-05-09T08:55:01Z

Introduce compile time check for files which should avoid using .bss section, because of the following reasons: - .bss section has not been zeroed yet, - initrd has not been moved to a safe location and could be overlapping with .bss section. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390/sclp: Add support for Store Data SCLP interface

2018-02-22T14:31:23Z

Add functions to retrieve data associated with an SCLP Store Data entity. Automatically retrieve data for the "config" entity during boot and make that data available to user-space via sysfs: /sys/firmware/sclp_sd/config/data Reading from this file will return config data contents. /sys/firmware/sclp_sd/config/reload Writing to this file will cause the latest version of data related to the config entity to be read from the SCLP interface. Generate a KOBJ_CHANGE whenever new data is retrieved. Signed-off-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky

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/sclp: disable FORTIFY_SOURCE for early sclp code

2017-12-13T15:57:02Z

Michal Suchánek reported the following compile error with FORTIFY_SOURCE enabled: drivers/s390/char/sclp_early_core.o: In function `memcpy': include/linux/string.h:340: undefined reference to `fortify_panic' To fix this simply disable FORTIFY_SOURCE on the early sclp code as well, which I forgot on the initial commit. Fixes: 79962038dffa ("s390: add support for FORTIFY_SOURCE") Reported-by: Michal Suchánek Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky