Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0b0968a3 authored by David S. Miller's avatar David S. Miller
Browse files

[SPARC64]: Fix D-cache corruption in mremap 



If we move a mapping from one virtual address to another,
and this changes the virtual color of the mapping to those
pages, we can see corrupt data due to D-cache aliasing.

Check for and deal with this by overriding the move_pte()
macro.  Set things up so that other platforms can cleanly
override the move_pte() macro too.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 951bc82c

include/asm-generic/pgtable.h

+1 −10
Original line number Diff line number Diff line
@@ -159,17 +159,8 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres 
#define lazy_mmu_prot_update(pte)	do { } while (0)

#endif



#ifndef __HAVE_ARCH_MULTIPLE_ZERO_PAGE

#ifndef __HAVE_ARCH_MOVE_PTE

#define move_pte(pte, prot, old_addr, new_addr)	(pte)

#else

#define move_pte(pte, prot, old_addr, new_addr)				\

({									\

 	pte_t newpte = (pte);						\

	if (pte_present(pte) && pfn_valid(pte_pfn(pte)) &&		\

			pte_page(pte) == ZERO_PAGE(old_addr))		\

		newpte = mk_pte(ZERO_PAGE(new_addr), (prot));		\

	newpte;								\

})

#endif



/*

include/asm-mips/pgtable.h

+9 −1
Original line number Diff line number Diff line
@@ -70,7 +70,15 @@ extern unsigned long zero_page_mask; 
#define ZERO_PAGE(vaddr) \

	(virt_to_page(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask)))



#define __HAVE_ARCH_MULTIPLE_ZERO_PAGE

#define __HAVE_ARCH_MOVE_PTE

#define move_pte(pte, prot, old_addr, new_addr)				\

({									\

 	pte_t newpte = (pte);						\

	if (pte_present(pte) && pfn_valid(pte_pfn(pte)) &&		\

			pte_page(pte) == ZERO_PAGE(old_addr))		\

		newpte = mk_pte(ZERO_PAGE(new_addr), (prot));		\

	newpte;								\

})



extern void paging_init(void);

include/asm-sparc64/pgtable.h

+17 −0
Original line number Diff line number Diff line
@@ -689,6 +689,23 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *p 
#define pte_clear(mm,addr,ptep)		\

	set_pte_at((mm), (addr), (ptep), __pte(0UL))



#ifdef DCACHE_ALIASING_POSSIBLE

#define __HAVE_ARCH_MOVE_PTE

#define move_pte(pte, prot, old_addr, new_addr)				\

({									\

 	pte_t newpte = (pte);						\

	if (tlb_type != hypervisor && pte_present(pte)) {		\

		unsigned long this_pfn = pte_pfn(pte);			\

									\

		if (pfn_valid(this_pfn) &&				\

		    (((old_addr) ^ (new_addr)) & (1 << 13)))		\

			flush_dcache_page_all(current->mm,		\

					      pfn_to_page(this_pfn));	\

	}								\

	newpte;								\

})

#endif



extern pgd_t swapper_pg_dir[2048];

extern pmd_t swapper_low_pmd_dir[2048];