Commit 643d95aa authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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Revert "x86/mm: Introduce lookup_address_in_mm()" 



Drop lookup_address_in_mm() now that KVM is providing it's own variant
of lookup_address_in_pgd() that is safe for use with user addresses, e.g.
guards against page tables being torn down.  A variant that provides a
non-init mm is inherently dangerous and flawed, as the only reason to use
an mm other than init_mm is to walk a userspace mapping, and
lookup_address_in_pgd() does not play nice with userspace mappings, e.g.
doesn't disable IRQs to block TLB shootdowns and doesn't use READ_ONCE()
to ensure an upper level entry isn't converted to a huge page between
checking the PAGE_SIZE bit and grabbing the address of the next level
down.

This reverts commit 13c72c060f1ba6f4eddd7b1c4f52a8aded43d6d9.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <YmwIi3bXr/1yhYV/@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 73331c5d

arch/x86/include/asm/pgtable_types.h

+0 −4
Original line number Diff line number Diff line
@@ -559,10 +559,6 @@ static inline void update_page_count(int level, unsigned long pages) { } 
extern pte_t *lookup_address(unsigned long address, unsigned int *level);

extern pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address,

				    unsigned int *level);



struct mm_struct;

extern pte_t *lookup_address_in_mm(struct mm_struct *mm, unsigned long address,

				   unsigned int *level);

extern pmd_t *lookup_pmd_address(unsigned long address);

extern phys_addr_t slow_virt_to_phys(void *__address);

extern int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn,

arch/x86/mm/pat/set_memory.c

+0 −11
Original line number Diff line number Diff line
@@ -638,17 +638,6 @@ pte_t *lookup_address(unsigned long address, unsigned int *level) 
}

EXPORT_SYMBOL_GPL(lookup_address);



/*

 * Lookup the page table entry for a virtual address in a given mm. Return a

 * pointer to the entry and the level of the mapping.

 */

pte_t *lookup_address_in_mm(struct mm_struct *mm, unsigned long address,

			    unsigned int *level)

{

	return lookup_address_in_pgd(pgd_offset(mm, address), address, level);

}

EXPORT_SYMBOL_GPL(lookup_address_in_mm);



static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address,

				  unsigned int *level)

{