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Commit 0d61f0b3 authored Jul 18, 2015 by Scott Wood

powerpc/booke64: Move mb() to __set_pte_at() with kernel-addr test



map_kernel() doesn't catch all places that create kernel PTEs.  In
particular, vmalloc() calls set_pte_at() directly.  This causes a
crash when booting a non-SMP kernel on e6500.

Move the sync to __set_pte(), to be executed only for kernel addresses.

Signed-off-by: Scott Wood <scottwood@freescale.com>

parent cf184dc2

arch/powerpc/include/asm/pgtable.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -169,6 +169,17 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
		* cases, and 32-bit non-hash with 32-bit PTEs.
		*/
		*ptep = pte;

		#ifdef CONFIG_PPC_BOOK3E_64
		/*
		* With hardware tablewalk, a sync is needed to ensure that
		* subsequent accesses see the PTE we just wrote. Unlike userspace
		* mappings, we can't tolerate spurious faults, so make sure
		* the new PTE will be seen the first time.
		*/
		if (is_kernel_addr(addr))
		mb();
		#endif
		#endif
		}

arch/powerpc/mm/pgtable_64.c

+0 −10

Original line number	Diff line number	Diff line
		@@ -149,17 +149,7 @@ int map_kernel_page(unsigned long ea, unsigned long pa, int flags)
		#endif /* !CONFIG_PPC_MMU_NOHASH */
		}

		#ifdef CONFIG_PPC_BOOK3E_64
		/*
		* With hardware tablewalk, a sync is needed to ensure that
		* subsequent accesses see the PTE we just wrote. Unlike userspace
		* mappings, we can't tolerate spurious faults, so make sure
		* the new PTE will be seen the first time.
		*/
		mb();
		#else
		smp_wmb();
		#endif
		return 0;
		}