kernel.git/arch/s390/kernel/early.c, branch linux-4.19.y

s390/kasan: fix early pgm check handler execution

2020-07-16T06:17:22Z

[ Upstream commit 998f5bbe3dbdab81c1cfb1aef7c3892f5d24f6c7 ] Currently if early_pgm_check_handler is called it ends up in pgm check loop. The problem is that early_pgm_check_handler is instrumented by KASAN but executed without DAT flag enabled which leads to addressing exception when KASAN checks try to access shadow memory. Fix that by executing early handlers with DAT flag on under KASAN as expected. Reported-and-tested-by: Alexander Egorenkov Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/early: improve machine detection

2019-01-31T07:14:35Z

commit 03aa047ef2db4985e444af6ee1c1dd084ad9fb4c upstream. Right now the early machine detection code check stsi 3.2.2 for "KVM" and set MACHINE_IS_VM if this is different. As the console detection uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux early for any non z/VM system that sets a different value than KVM. So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR, MACHINE_IS_VM, or MACHINE_IS_KVM. CC: stable@vger.kernel.org Reviewed-by: Heiko Carstens Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/boot: block uncompressed vmlinux booting attempts

2018-07-02T09:25:05Z

Since the plain vmlinux ELF file no longer carries all necessary parts for starting up (like the entry point and decompressor), add a check which would block boot process and encourage users to use bzImage or arch/s390/boot/compressed/vmlinux instead. The check relies on s390 linux entry point ABI definition, which is only present in bzImage and arch/s390/boot/compressed/vmlinux. Reported-by: Guenter Roeck Tested-by: Guenter Roeck Acked-by: Cornelia Huck Acked-by: Christian Borntraeger Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390/early: move functions which may not access bss section to extra file

2018-05-09T08:55:01Z

Move functions which may not access bss section to extra file. This makes it easier to verify that all early functions which may not rely on an initialized bss section are not accessing it. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/early: get rid of #ifdef CONFIG_BLK_DEV_INITRD

2018-05-09T08:55:01Z

Use IS_ENABLED to get rid of an #ifdef statement. Reviewed-by: Christian Borntraeger Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/early: get rid of memmove_early

2018-05-09T08:55:01Z

memmove_early was introduced with commit d543a106f96d6 ("s390: fix initrd corruptions with gcov/kcov instrumented kernels"). The reason for writing this extra memmove implementation was to be able to move memory from an unknown location (aka SCSI IPL parameter block) to a known location. This had to done early before it was known if the SCSI IPL parameter block pointer was valid or not, and therefore the memmove implementation was supposed to be able to handle program checks. The code has been changed and especially with commit d08091ac9654 ("s390/ipl: rely on diag308 store to get ipl info") and commit b4623d4e5b23 ("s390: provide memmove implementation") there is no need to have a memmove version that can handle program checks, and in addition it cannot be gcov/kcov instrumented anymore. Reviewed-by: Christian Borntraeger Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/ipl: rely on diag308 store to get ipl info

2018-04-10T05:38:59Z

For both ccw and fcp boot retrieve ipl info from ipl block received via diag308 store. Old scsi ipl parm block handling and cio_get_iplinfo are removed. Ipl type is deducted from ipl block (if valid). Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390/lpp: use assembler alternatives for the LPP instruction

2018-03-28T06:38:28Z

With the new macros for CPU alternatives the MACHINE_FLAG_LPP check around the LPP instruction can be optimized. After this is done the flag can be removed. Signed-off-by: Martin Schwidefsky

s390: unify linker symbols usage

2018-02-27T07:05:23Z

Common code defines linker symbols which denote sections start/end in a form of char []. Referencing those symbols as _symbol or &_symbol yields the same result, but "_symbol" form is more widespread across newly written code. Convert s390 specific code to this style. Also removes unused _text symbol definition in boot/compressed/misc.c. Signed-off-by: Vasily Gorbik Acked-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: add options to change branch prediction behaviour for the kernel

2018-02-05T12:49:17Z

Add the PPA instruction to the system entry and exit path to switch the kernel to a different branch prediction behaviour. The instructions are added via CPU alternatives and can be disabled with the "nospec" or the "nobp=0" kernel parameter. If the default behaviour selected with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be used to enable the changed kernel branch prediction. Acked-by: Cornelia Huck Signed-off-by: Martin Schwidefsky