[PATCH 1/3] powerpc/64s: Disable preemption in hash lazy mmu mode
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2022-10-13 15:18:51
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
apply_to_page_range on kernel pages does not disable preemption, which is a requirement for hash's lazy mmu mode, which keeps track of the TLBs to flush with a per-cpu array. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/include/asm/book3s/64/tlbflush-hash.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
index fab8332fe1ad..751921f6db46 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h@@ -32,6 +32,11 @@ static inline void arch_enter_lazy_mmu_mode(void) if (radix_enabled()) return; + /* + * apply_to_page_range can call us this preempt enabled when + * operating on kernel page tables. + */ + preempt_disable(); batch = this_cpu_ptr(&ppc64_tlb_batch); batch->active = 1; }
@@ -47,6 +52,7 @@ static inline void arch_leave_lazy_mmu_mode(void) if (batch->index) __flush_tlb_pending(batch); batch->active = 0; + preempt_enable(); } #define arch_flush_lazy_mmu_mode() do {} while (0)
--
2.37.2