Martin Schwidefsky a38662084c s390/mm: always force a load of the primary ASCE on context switch ... The ASCE of an mm_struct can be modified after a task has been created, e.g. via crst_table_downgrade for a compat process. The active_mm logic to avoid the switch_mm call if the next task is a kernel thread can lead to a situation where switch_mm is called where 'prev == next' is true but 'prev->context.asce == next->context.asce' is not. This can lead to a situation where a CPU uses the outdated ASCE to run a task. The result can be a crash, endless loops and really subtle problem due to TLBs being created with an invalid ASCE. Cc: stable@kernel.org # v3.15+ Fixes: 53e857f308 ("s390/mm,tlb: race of lazy TLB flush vs. recreation") Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>		2019-01-11 17:12:02 +01:00
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asm	s390/mm: always force a load of the primary ASCE on context switch	2019-01-11 17:12:02 +01:00
uapi/asm	arch: remove redundant UAPI generic-y defines	2019-01-06 10:22:15 +09:00