diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index dc8f99ee305fc4edd43232abdc0e5564b2c15434..7d7bcf990e9917abf9ab98208417a6d5ef59d017 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -27,13 +27,20 @@ do { \ * Largely same as above, but only sets the access flags (dirty, * accessed, and writable). Furthermore, we know it always gets set * to a "more permissive" setting, which allows most architectures - * to optimize this. + * to optimize this. We return whether the PTE actually changed, which + * in turn instructs the caller to do things like update__mmu_cache. + * This used to be done in the caller, but sparc needs minor faults to + * force that call on sun4c so we changed this macro slightly */ #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ -do { \ - set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \ - flush_tlb_page(__vma, __address); \ -} while (0) +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) { \ + set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \ + flush_tlb_page(__vma, __address); \ + } \ + __changed; \ +}) #endif #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h index d62bdb029efa3d5cc6ad562a24b6f0710ab2409e..628fa7747d0cce02dfd866c181c31dbd413c952c 100644 --- a/include/asm-i386/pgtable.h +++ b/include/asm-i386/pgtable.h @@ -285,13 +285,15 @@ static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep) */ #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS #define ptep_set_access_flags(vma, address, ptep, entry, dirty) \ -do { \ - if (dirty) { \ +({ \ + int __changed = !pte_same(*(ptep), entry); \ + if (__changed && dirty) { \ (ptep)->pte_low = (entry).pte_low; \ pte_update_defer((vma)->vm_mm, (address), (ptep)); \ flush_tlb_page(vma, address); \ } \ -} while (0) + __changed; \ +}) #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY #define ptep_test_and_clear_dirty(vma, addr, ptep) ({ \ diff --git a/include/asm-ia64/pgtable.h b/include/asm-ia64/pgtable.h index 670b706411b88c01c5a1785e467f387510ecfe2a..6580f31b31352c414fa55f6e5ddadcf287a9e9e3 100644 --- a/include/asm-ia64/pgtable.h +++ b/include/asm-ia64/pgtable.h @@ -533,16 +533,23 @@ extern void lazy_mmu_prot_update (pte_t pte); * daccess_bit in ivt.S). */ #ifdef CONFIG_SMP -# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \ -do { \ - if (__safely_writable) { \ - set_pte(__ptep, __entry); \ - flush_tlb_page(__vma, __addr); \ - } \ -} while (0) +# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \ +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed && __safely_writable) { \ + set_pte(__ptep, __entry); \ + flush_tlb_page(__vma, __addr); \ + } \ + __changed; \ +}) #else -# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \ - ptep_establish(__vma, __addr, __ptep, __entry) +# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \ +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) \ + ptep_establish(__vma, __addr, __ptep, __entry); \ + __changed; \ +}) #endif # ifdef CONFIG_VIRTUAL_MEM_MAP diff --git a/include/asm-powerpc/pgtable-ppc32.h b/include/asm-powerpc/pgtable-ppc32.h index c863bdb2889c11fae3879c38be57aef299ef9fbd..7fb730c62f8332cb8cc19a37858f557a8833bf10 100644 --- a/include/asm-powerpc/pgtable-ppc32.h +++ b/include/asm-powerpc/pgtable-ppc32.h @@ -673,10 +673,14 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty) } #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ - do { \ - __ptep_set_access_flags(__ptep, __entry, __dirty); \ - flush_tlb_page_nohash(__vma, __address); \ - } while(0) +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) { \ + __ptep_set_access_flags(__ptep, __entry, __dirty); \ + flush_tlb_page_nohash(__vma, __address); \ + } \ + __changed; \ +}) /* * Macro to mark a page protection value as "uncacheable". diff --git a/include/asm-powerpc/pgtable-ppc64.h b/include/asm-powerpc/pgtable-ppc64.h index 704c4e669fe0ac9a1b72818b2922d97732d980b0..3cfd98f44bfe82286b55b1ca5aa2af442e993c4c 100644 --- a/include/asm-powerpc/pgtable-ppc64.h +++ b/include/asm-powerpc/pgtable-ppc64.h @@ -413,10 +413,14 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty) :"cc"); } #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ - do { \ - __ptep_set_access_flags(__ptep, __entry, __dirty); \ - flush_tlb_page_nohash(__vma, __address); \ - } while(0) +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) { \ + __ptep_set_access_flags(__ptep, __entry, __dirty); \ + flush_tlb_page_nohash(__vma, __address); \ + } \ + __changed; \ +}) /* * Macro to mark a page protection value as "uncacheable". diff --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h index bed452d4a5f0b1486990b223f7a1e711ae20ac81..9d0ce9ff584026df772125dff65d5e03c85395b4 100644 --- a/include/asm-ppc/pgtable.h +++ b/include/asm-ppc/pgtable.h @@ -694,10 +694,14 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty) } #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ - do { \ - __ptep_set_access_flags(__ptep, __entry, __dirty); \ - flush_tlb_page_nohash(__vma, __address); \ - } while(0) +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) { \ + __ptep_set_access_flags(__ptep, __entry, __dirty); \ + flush_tlb_page_nohash(__vma, __address); \ + } \ + __changed; \ +}) /* * Macro to mark a page protection value as "uncacheable". diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h index 8fe8d42e64c3dcafa0fc486cc8ce46ef723b5593..0a307bb2f35328d784f15c77fe27cd5f3e0814a9 100644 --- a/include/asm-s390/pgtable.h +++ b/include/asm-s390/pgtable.h @@ -744,7 +744,12 @@ ptep_establish(struct vm_area_struct *vma, } #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ - ptep_establish(__vma, __address, __ptep, __entry) +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) \ + ptep_establish(__vma, __address, __ptep, __entry); \ + __changed; \ +}) /* * Test and clear dirty bit in storage key. diff --git a/include/asm-sparc/pgtable.h b/include/asm-sparc/pgtable.h index 4f0a5ba0d6a033cf9c8e0923f343556f550914fa..59229aeba27b9c51a15a39985c088719d8bb5811 100644 --- a/include/asm-sparc/pgtable.h +++ b/include/asm-sparc/pgtable.h @@ -446,6 +446,17 @@ extern int io_remap_pfn_range(struct vm_area_struct *vma, #define GET_IOSPACE(pfn) (pfn >> (BITS_PER_LONG - 4)) #define GET_PFN(pfn) (pfn & 0x0fffffffUL) +#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS +#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) { \ + set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \ + flush_tlb_page(__vma, __address); \ + } \ + (sparc_cpu_model == sun4c) || __changed; \ +}) + #include #endif /* !(__ASSEMBLY__) */ diff --git a/include/asm-x86_64/pgtable.h b/include/asm-x86_64/pgtable.h index 08b9831f2e14f1efab15d594dd594d2a326cc098..0a71e0b9a619c162235f50bdd358da0a4942ff78 100644 --- a/include/asm-x86_64/pgtable.h +++ b/include/asm-x86_64/pgtable.h @@ -395,12 +395,14 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) * bit at the same time. */ #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ - do { \ - if (__dirty) { \ - set_pte(__ptep, __entry); \ - flush_tlb_page(__vma, __address); \ - } \ - } while (0) +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed && __dirty) { \ + set_pte(__ptep, __entry); \ + flush_tlb_page(__vma, __address); \ + } \ + __changed; \ +}) /* Encode and de-code a swap entry */ #define __swp_type(x) (((x).val >> 1) & 0x3f) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index eb7180db303326f73f7e099f84e2557e84cc87b1..a45d1f0691cecb63e088d02fb3ff287f025e4d78 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -326,9 +326,10 @@ static void set_huge_ptep_writable(struct vm_area_struct *vma, pte_t entry; entry = pte_mkwrite(pte_mkdirty(*ptep)); - ptep_set_access_flags(vma, address, ptep, entry, 1); - update_mmu_cache(vma, address, entry); - lazy_mmu_prot_update(entry); + if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { + update_mmu_cache(vma, address, entry); + lazy_mmu_prot_update(entry); + } } diff --git a/mm/memory.c b/mm/memory.c index cb94488ab96dad4eb3840fa037a7b08673154674..f64cbf9baa3633fc1755f675ec2b46c920c4ecef 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1691,9 +1691,10 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, flush_cache_page(vma, address, pte_pfn(orig_pte)); entry = pte_mkyoung(orig_pte); entry = maybe_mkwrite(pte_mkdirty(entry), vma); - ptep_set_access_flags(vma, address, page_table, entry, 1); - update_mmu_cache(vma, address, entry); - lazy_mmu_prot_update(entry); + if (ptep_set_access_flags(vma, address, page_table, entry,1)) { + update_mmu_cache(vma, address, entry); + lazy_mmu_prot_update(entry); + } ret |= VM_FAULT_WRITE; goto unlock; } @@ -2525,10 +2526,9 @@ static inline int handle_pte_fault(struct mm_struct *mm, pte_t *pte, pmd_t *pmd, int write_access) { pte_t entry; - pte_t old_entry; spinlock_t *ptl; - old_entry = entry = *pte; + entry = *pte; if (!pte_present(entry)) { if (pte_none(entry)) { if (vma->vm_ops) { @@ -2561,8 +2561,7 @@ static inline int handle_pte_fault(struct mm_struct *mm, entry = pte_mkdirty(entry); } entry = pte_mkyoung(entry); - if (!pte_same(old_entry, entry)) { - ptep_set_access_flags(vma, address, pte, entry, write_access); + if (ptep_set_access_flags(vma, address, pte, entry, write_access)) { update_mmu_cache(vma, address, entry); lazy_mmu_prot_update(entry); } else {