Commit 66acd460 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc: select ARCH_WANT_IRQS_OFF_ACTIVATE_MM 



powerpc uses IPIs in some situations to switch a kernel thread away
from a lazy tlb mm, which is subject to the TLB flushing race
described in the changelog introducing ARCH_WANT_IRQS_OFF_ACTIVATE_MM.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914045219.3736466-3-npiggin@gmail.com
parent d53c3dfb

arch/powerpc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -149,6 +149,7 @@ config PPC 
	select ARCH_USE_QUEUED_RWLOCKS		if PPC_QUEUED_SPINLOCKS

	select ARCH_USE_QUEUED_SPINLOCKS	if PPC_QUEUED_SPINLOCKS

	select ARCH_WANT_IPC_PARSE_VERSION

	select ARCH_WANT_IRQS_OFF_ACTIVATE_MM

	select ARCH_WEAK_RELEASE_ACQUIRE

	select BINFMT_ELF

	select BUILDTIME_TABLE_SORT

arch/powerpc/include/asm/mmu_context.h

+1 −1
Original line number Diff line number Diff line
@@ -244,7 +244,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 
 */

static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)

{

	switch_mm(prev, next, current);

	switch_mm_irqs_off(prev, next, current);

}



/* We don't currently use enter_lazy_tlb() for anything */