diff options
author | Zhang, Yanmin <yanmin_zhang@linux.intel.com> | 2006-03-22 11:08:50 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-22 18:54:03 +0300 |
commit | 8f860591ffb29738cf5539b6fbf27f50dcdeb380 (patch) | |
tree | 4265e45c4a79d86a16cd5175a836e8c531be8117 | |
parent | aed75ff3caafce404d9be7f0c088716375be5279 (diff) | |
download | linux-8f860591ffb29738cf5539b6fbf27f50dcdeb380.tar.xz |
[PATCH] Enable mprotect on huge pages
2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
mprotect.
From: David Gibson <david@gibson.dropbear.id.au>
Remove a test from the mprotect() path which checks that the mprotect()ed
range on a hugepage VMA is hugepage aligned (yes, really, the sense of
is_aligned_hugepage_range() is the opposite of what you'd guess :-/).
In fact, we don't need this test. If the given addresses match the
beginning/end of a hugepage VMA they must already be suitably aligned. If
they don't, then mprotect_fixup() will attempt to split the VMA. The very
first test in split_vma() will check for a badly aligned address on a
hugepage VMA and return -EINVAL if necessary.
From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
On i386 and x86-64, pte flag _PAGE_PSE collides with _PAGE_PROTNONE. The
identify of hugetlb pte is lost when changing page protection via mprotect.
A page fault occurs later will trigger a bug check in huge_pte_alloc().
The fix is to always make new pte a hugetlb pte and also to clean up
legacy code where _PAGE_PRESENT is forced on in the pre-faulting day.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | include/asm-i386/pgtable.h | 5 | ||||
-rw-r--r-- | include/asm-ia64/pgtable.h | 2 | ||||
-rw-r--r-- | include/asm-x86_64/pgtable.h | 4 | ||||
-rw-r--r-- | include/linux/hugetlb.h | 4 | ||||
-rw-r--r-- | mm/hugetlb.c | 29 | ||||
-rw-r--r-- | mm/mprotect.c | 12 |
6 files changed, 43 insertions, 13 deletions
diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h index 088a945bf26b..ee056c41a9fb 100644 --- a/include/asm-i386/pgtable.h +++ b/include/asm-i386/pgtable.h @@ -219,13 +219,12 @@ extern unsigned long pg0[]; * The following only work if pte_present() is true. * Undefined behaviour if not.. */ -#define __LARGE_PTE (_PAGE_PSE | _PAGE_PRESENT) static inline int pte_user(pte_t pte) { return (pte).pte_low & _PAGE_USER; } static inline int pte_read(pte_t pte) { return (pte).pte_low & _PAGE_USER; } static inline int pte_dirty(pte_t pte) { return (pte).pte_low & _PAGE_DIRTY; } static inline int pte_young(pte_t pte) { return (pte).pte_low & _PAGE_ACCESSED; } static inline int pte_write(pte_t pte) { return (pte).pte_low & _PAGE_RW; } -static inline int pte_huge(pte_t pte) { return ((pte).pte_low & __LARGE_PTE) == __LARGE_PTE; } +static inline int pte_huge(pte_t pte) { return (pte).pte_low & _PAGE_PSE; } /* * The following only works if pte_present() is not true. @@ -242,7 +241,7 @@ static inline pte_t pte_mkexec(pte_t pte) { (pte).pte_low |= _PAGE_USER; return static inline pte_t pte_mkdirty(pte_t pte) { (pte).pte_low |= _PAGE_DIRTY; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { (pte).pte_low |= _PAGE_ACCESSED; return pte; } static inline pte_t pte_mkwrite(pte_t pte) { (pte).pte_low |= _PAGE_RW; return pte; } -static inline pte_t pte_mkhuge(pte_t pte) { (pte).pte_low |= __LARGE_PTE; return pte; } +static inline pte_t pte_mkhuge(pte_t pte) { (pte).pte_low |= _PAGE_PSE; return pte; } #ifdef CONFIG_X86_PAE # include <asm/pgtable-3level.h> diff --git a/include/asm-ia64/pgtable.h b/include/asm-ia64/pgtable.h index e2560c58384b..5890972a69bf 100644 --- a/include/asm-ia64/pgtable.h +++ b/include/asm-ia64/pgtable.h @@ -314,7 +314,7 @@ ia64_phys_addr_valid (unsigned long addr) #define pte_mkyoung(pte) (__pte(pte_val(pte) | _PAGE_A)) #define pte_mkclean(pte) (__pte(pte_val(pte) & ~_PAGE_D)) #define pte_mkdirty(pte) (__pte(pte_val(pte) | _PAGE_D)) -#define pte_mkhuge(pte) (__pte(pte_val(pte) | _PAGE_P)) +#define pte_mkhuge(pte) (__pte(pte_val(pte))) /* * Macro to a page protection value as "uncacheable". Note that "protection" is really a diff --git a/include/asm-x86_64/pgtable.h b/include/asm-x86_64/pgtable.h index 715fd94cf577..a617d364d08d 100644 --- a/include/asm-x86_64/pgtable.h +++ b/include/asm-x86_64/pgtable.h @@ -273,7 +273,7 @@ static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW; } static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } -static inline int pte_huge(pte_t pte) { return (pte_val(pte) & __LARGE_PTE) == __LARGE_PTE; } +static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_PSE; } static inline pte_t pte_rdprotect(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_USER)); return pte; } static inline pte_t pte_exprotect(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_USER)); return pte; } @@ -285,7 +285,7 @@ static inline pte_t pte_mkexec(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _ static inline pte_t pte_mkdirty(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_DIRTY)); return pte; } static inline pte_t pte_mkyoung(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_ACCESSED)); return pte; } static inline pte_t pte_mkwrite(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_RW)); return pte; } -static inline pte_t pte_mkhuge(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | __LARGE_PTE)); return pte; } +static inline pte_t pte_mkhuge(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_PSE)); return pte; } struct vm_area_struct; diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 68d82ad6b17c..fa83836b63d2 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -41,6 +41,8 @@ struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write); int is_aligned_hugepage_range(unsigned long addr, unsigned long len); int pmd_huge(pmd_t pmd); +void hugetlb_change_protection(struct vm_area_struct *vma, + unsigned long address, unsigned long end, pgprot_t newprot); #ifndef ARCH_HAS_HUGEPAGE_ONLY_RANGE #define is_hugepage_only_range(mm, addr, len) 0 @@ -101,6 +103,8 @@ static inline unsigned long hugetlb_total_pages(void) #define free_huge_page(p) ({ (void)(p); BUG(); }) #define hugetlb_fault(mm, vma, addr, write) ({ BUG(); 0; }) +#define hugetlb_change_protection(vma, address, end, newprot) + #ifndef HPAGE_MASK #define HPAGE_MASK PAGE_MASK /* Keep the compiler happy */ #define HPAGE_SIZE PAGE_SIZE diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 20117a4b8ab6..783098f6cf8e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -565,3 +565,32 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, return i; } + +void hugetlb_change_protection(struct vm_area_struct *vma, + unsigned long address, unsigned long end, pgprot_t newprot) +{ + struct mm_struct *mm = vma->vm_mm; + unsigned long start = address; + pte_t *ptep; + pte_t pte; + + BUG_ON(address >= end); + flush_cache_range(vma, address, end); + + spin_lock(&mm->page_table_lock); + for (; address < end; address += HPAGE_SIZE) { + ptep = huge_pte_offset(mm, address); + if (!ptep) + continue; + if (!pte_none(*ptep)) { + pte = huge_ptep_get_and_clear(mm, address, ptep); + pte = pte_mkhuge(pte_modify(pte, newprot)); + set_huge_pte_at(mm, address, ptep, pte); + lazy_mmu_prot_update(pte); + } + } + spin_unlock(&mm->page_table_lock); + + flush_tlb_range(vma, start, end); +} + diff --git a/mm/mprotect.c b/mm/mprotect.c index 653b8571c1ed..4c14d4289b61 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -124,7 +124,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, * a MAP_NORESERVE private mapping to writable will now reserve. */ if (newflags & VM_WRITE) { - if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) { + if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))) { charged = nrpages; if (security_vm_enough_memory(charged)) return -ENOMEM; @@ -166,7 +166,10 @@ success: */ vma->vm_flags = newflags; vma->vm_page_prot = newprot; - change_protection(vma, start, end, newprot); + if (is_vm_hugetlb_page(vma)) + hugetlb_change_protection(vma, start, end, newprot); + else + change_protection(vma, start, end, newprot); vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); vm_stat_account(mm, newflags, vma->vm_file, nrpages); return 0; @@ -240,11 +243,6 @@ sys_mprotect(unsigned long start, size_t len, unsigned long prot) /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ - if (is_vm_hugetlb_page(vma)) { - error = -EACCES; - goto out; - } - newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); /* newflags >> 4 shift VM_MAY% in place of VM_% */ |