[PATCH 1/3] powerpc/64s: Disable preemption in hash lazy mmu mode
Nicholas Piggin
npiggin at gmail.com
Fri Oct 14 02:16:45 AEDT 2022
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 at roeck-us.net>
Signed-off-by: Nicholas Piggin <npiggin at 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
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