#include <linux/delayacct.h>
#include <linux/init.h>
#include <linux/writeback.h>
+#include <linux/memcontrol.h>
+#include <linux/mmu_notifier.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
#include <linux/swapops.h>
#include <linux/elf.h>
+#include "internal.h"
+
#ifndef CONFIG_NEED_MULTIPLE_NODES
/* use the per-pgdat data instead for discontigmem - mbligh */
unsigned long max_mapnr;
* and ZONE_HIGHMEM.
*/
void * high_memory;
-unsigned long vmalloc_earlyreserve;
EXPORT_SYMBOL(num_physpages);
EXPORT_SYMBOL(high_memory);
-EXPORT_SYMBOL(vmalloc_earlyreserve);
-int randomize_va_space __read_mostly = 1;
+/*
+ * Randomize the address space (stacks, mmaps, brk, etc.).
+ *
+ * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization,
+ * as ancient (libc5 based) binaries can segfault. )
+ */
+int randomize_va_space __read_mostly =
+#ifdef CONFIG_COMPAT_BRK
+ 1;
+#else
+ 2;
+#endif
static int __init disable_randmaps(char *s)
{
*/
static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd)
{
- struct page *page = pmd_page(*pmd);
+ pgtable_t token = pmd_pgtable(*pmd);
pmd_clear(pmd);
- pte_lock_deinit(page);
- pte_free_tlb(tlb, page);
- dec_zone_page_state(page, NR_PAGETABLE);
+ pte_free_tlb(tlb, token);
tlb->mm->nr_ptes--;
}
*
* Must be called with pagetable lock held.
*/
-void free_pgd_range(struct mmu_gather **tlb,
+void free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
return;
start = addr;
- pgd = pgd_offset((*tlb)->mm, addr);
+ pgd = pgd_offset(tlb->mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
- free_pud_range(*tlb, pgd, addr, next, floor, ceiling);
+ free_pud_range(tlb, pgd, addr, next, floor, ceiling);
} while (pgd++, addr = next, addr != end);
-
- if (!(*tlb)->fullmm)
- flush_tlb_pgtables((*tlb)->mm, start, end);
}
-void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma,
+void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
unsigned long floor, unsigned long ceiling)
{
while (vma) {
int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
{
- struct page *new = pte_alloc_one(mm, address);
+ pgtable_t new = pte_alloc_one(mm, address);
if (!new)
return -ENOMEM;
- pte_lock_init(new);
+ /*
+ * Ensure all pte setup (eg. pte page lock and page clearing) are
+ * visible before the pte is made visible to other CPUs by being
+ * put into page tables.
+ *
+ * The other side of the story is the pointer chasing in the page
+ * table walking code (when walking the page table without locking;
+ * ie. most of the time). Fortunately, these data accesses consist
+ * of a chain of data-dependent loads, meaning most CPUs (alpha
+ * being the notable exception) will already guarantee loads are
+ * seen in-order. See the alpha page table accessors for the
+ * smp_read_barrier_depends() barriers in page table walking code.
+ */
+ smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */
+
spin_lock(&mm->page_table_lock);
- if (pmd_present(*pmd)) { /* Another has populated it */
- pte_lock_deinit(new);
- pte_free(new);
- } else {
+ if (!pmd_present(*pmd)) { /* Has another populated it ? */
mm->nr_ptes++;
- inc_zone_page_state(new, NR_PAGETABLE);
pmd_populate(mm, pmd, new);
+ new = NULL;
}
spin_unlock(&mm->page_table_lock);
+ if (new)
+ pte_free(mm, new);
return 0;
}
if (!new)
return -ENOMEM;
+ smp_wmb(); /* See comment in __pte_alloc */
+
spin_lock(&init_mm.page_table_lock);
- if (pmd_present(*pmd)) /* Another has populated it */
- pte_free_kernel(new);
- else
+ if (!pmd_present(*pmd)) { /* Has another populated it ? */
pmd_populate_kernel(&init_mm, pmd, new);
+ new = NULL;
+ }
spin_unlock(&init_mm.page_table_lock);
+ if (new)
+ pte_free_kernel(&init_mm, new);
return 0;
}
*
* The calling function must still handle the error.
*/
-void print_bad_pte(struct vm_area_struct *vma, pte_t pte, unsigned long vaddr)
+static void print_bad_pte(struct vm_area_struct *vma, pte_t pte,
+ unsigned long vaddr)
{
printk(KERN_ERR "Bad pte = %08llx, process = %s, "
"vm_flags = %lx, vaddr = %lx\n",
}
/*
- * This function gets the "struct page" associated with a pte.
+ * vm_normal_page -- This function gets the "struct page" associated with a pte.
+ *
+ * "Special" mappings do not wish to be associated with a "struct page" (either
+ * it doesn't exist, or it exists but they don't want to touch it). In this
+ * case, NULL is returned here. "Normal" mappings do have a struct page.
*
- * NOTE! Some mappings do not have "struct pages". A raw PFN mapping
- * will have each page table entry just pointing to a raw page frame
- * number, and as far as the VM layer is concerned, those do not have
- * pages associated with them - even if the PFN might point to memory
- * that otherwise is perfectly fine and has a "struct page".
+ * There are 2 broad cases. Firstly, an architecture may define a pte_special()
+ * pte bit, in which case this function is trivial. Secondly, an architecture
+ * may not have a spare pte bit, which requires a more complicated scheme,
+ * described below.
*
- * The way we recognize those mappings is through the rules set up
- * by "remap_pfn_range()": the vma will have the VM_PFNMAP bit set,
- * and the vm_pgoff will point to the first PFN mapped: thus every
- * page that is a raw mapping will always honor the rule
+ * A raw VM_PFNMAP mapping (ie. one that is not COWed) is always considered a
+ * special mapping (even if there are underlying and valid "struct pages").
+ * COWed pages of a VM_PFNMAP are always normal.
+ *
+ * The way we recognize COWed pages within VM_PFNMAP mappings is through the
+ * rules set up by "remap_pfn_range()": the vma will have the VM_PFNMAP bit
+ * set, and the vm_pgoff will point to the first PFN mapped: thus every special
+ * mapping will always honor the rule
*
* pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT)
*
- * and if that isn't true, the page has been COW'ed (in which case it
- * _does_ have a "struct page" associated with it even if it is in a
- * VM_PFNMAP range).
+ * And for normal mappings this is false.
+ *
+ * This restricts such mappings to be a linear translation from virtual address
+ * to pfn. To get around this restriction, we allow arbitrary mappings so long
+ * as the vma is not a COW mapping; in that case, we know that all ptes are
+ * special (because none can have been COWed).
+ *
+ *
+ * In order to support COW of arbitrary special mappings, we have VM_MIXEDMAP.
+ *
+ * VM_MIXEDMAP mappings can likewise contain memory with or without "struct
+ * page" backing, however the difference is that _all_ pages with a struct
+ * page (that is, those where pfn_valid is true) are refcounted and considered
+ * normal pages by the VM. The disadvantage is that pages are refcounted
+ * (which can be slower and simply not an option for some PFNMAP users). The
+ * advantage is that we don't have to follow the strict linearity rule of
+ * PFNMAP mappings in order to support COWable mappings.
+ *
*/
-struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+#ifdef __HAVE_ARCH_PTE_SPECIAL
+# define HAVE_PTE_SPECIAL 1
+#else
+# define HAVE_PTE_SPECIAL 0
+#endif
+struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
+ pte_t pte)
{
- unsigned long pfn = pte_pfn(pte);
+ unsigned long pfn;
- if (unlikely(vma->vm_flags & VM_PFNMAP)) {
- unsigned long off = (addr - vma->vm_start) >> PAGE_SHIFT;
- if (pfn == vma->vm_pgoff + off)
- return NULL;
- if (!is_cow_mapping(vma->vm_flags))
- return NULL;
+ if (HAVE_PTE_SPECIAL) {
+ if (likely(!pte_special(pte))) {
+ VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
+ return pte_page(pte);
+ }
+ VM_BUG_ON(!(vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)));
+ return NULL;
}
- /*
- * Add some anal sanity checks for now. Eventually,
- * we should just do "return pfn_to_page(pfn)", but
- * in the meantime we check that we get a valid pfn,
- * and that the resulting page looks ok.
- */
- if (unlikely(!pfn_valid(pfn))) {
- print_bad_pte(vma, pte, addr);
- return NULL;
+ /* !HAVE_PTE_SPECIAL case follows: */
+
+ pfn = pte_pfn(pte);
+
+ if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
+ if (vma->vm_flags & VM_MIXEDMAP) {
+ if (!pfn_valid(pfn))
+ return NULL;
+ goto out;
+ } else {
+ unsigned long off;
+ off = (addr - vma->vm_start) >> PAGE_SHIFT;
+ if (pfn == vma->vm_pgoff + off)
+ return NULL;
+ if (!is_cow_mapping(vma->vm_flags))
+ return NULL;
+ }
}
+ VM_BUG_ON(!pfn_valid(pfn));
+
/*
- * NOTE! We still have PageReserved() pages in the page
- * tables.
+ * NOTE! We still have PageReserved() pages in the page tables.
*
- * The PAGE_ZERO() pages and various VDSO mappings can
- * cause them to exist.
+ * eg. VDSO mappings can cause them to exist.
*/
+out:
return pfn_to_page(pfn);
}
page = vm_normal_page(vma, addr, pte);
if (page) {
get_page(page);
- page_dup_rmap(page);
+ page_dup_rmap(page, vma, addr);
rss[!!PageAnon(page)]++;
}
if (progress >= 32) {
progress = 0;
if (need_resched() ||
- need_lockbreak(src_ptl) ||
- need_lockbreak(dst_ptl))
+ spin_needbreak(src_ptl) || spin_needbreak(dst_ptl))
break;
}
if (pte_none(*src_pte)) {
unsigned long next;
unsigned long addr = vma->vm_start;
unsigned long end = vma->vm_end;
+ int ret;
/*
* Don't copy ptes where a page fault will fill them correctly.
if (is_vm_hugetlb_page(vma))
return copy_hugetlb_page_range(dst_mm, src_mm, vma);
+ /*
+ * We need to invalidate the secondary MMU mappings only when
+ * there could be a permission downgrade on the ptes of the
+ * parent mm. And a permission downgrade will only happen if
+ * is_cow_mapping() returns true.
+ */
+ if (is_cow_mapping(vma->vm_flags))
+ mmu_notifier_invalidate_range_start(src_mm, addr, end);
+
+ ret = 0;
dst_pgd = pgd_offset(dst_mm, addr);
src_pgd = pgd_offset(src_mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(src_pgd))
continue;
- if (copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd,
- vma, addr, next))
- return -ENOMEM;
+ if (unlikely(copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd,
+ vma, addr, next))) {
+ ret = -ENOMEM;
+ break;
+ }
} while (dst_pgd++, src_pgd++, addr = next, addr != end);
- return 0;
+
+ if (is_cow_mapping(vma->vm_flags))
+ mmu_notifier_invalidate_range_end(src_mm,
+ vma->vm_start, end);
+ return ret;
}
static unsigned long zap_pte_range(struct mmu_gather *tlb,
if (pte_dirty(ptent))
set_page_dirty(page);
if (pte_young(ptent))
- mark_page_accessed(page);
+ SetPageReferenced(page);
file_rss--;
}
page_remove_rmap(page, vma);
unsigned long start = start_addr;
spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
int fullmm = (*tlbp)->fullmm;
+ struct mm_struct *mm = vma->vm_mm;
+ mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
unsigned long end;
}
if (unlikely(is_vm_hugetlb_page(vma))) {
- unmap_hugepage_range(vma, start, end);
- zap_work -= (end - start) /
- (HPAGE_SIZE / PAGE_SIZE);
+ /*
+ * It is undesirable to test vma->vm_file as it
+ * should be non-null for valid hugetlb area.
+ * However, vm_file will be NULL in the error
+ * cleanup path of do_mmap_pgoff. When
+ * hugetlbfs ->mmap method fails,
+ * do_mmap_pgoff() nullifies vma->vm_file
+ * before calling this function to clean up.
+ * Since no pte has actually been setup, it is
+ * safe to do nothing in this case.
+ */
+ if (vma->vm_file) {
+ unmap_hugepage_range(vma, start, end, NULL);
+ zap_work -= (end - start) /
+ pages_per_huge_page(hstate_vma(vma));
+ }
+
start = end;
} else
start = unmap_page_range(*tlbp, vma,
tlb_finish_mmu(*tlbp, tlb_start, start);
if (need_resched() ||
- (i_mmap_lock && need_lockbreak(i_mmap_lock))) {
+ (i_mmap_lock && spin_needbreak(i_mmap_lock))) {
if (i_mmap_lock) {
*tlbp = NULL;
goto out;
}
}
out:
+ mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
return start; /* which is now the end (or restart) address */
}
return end;
}
+/**
+ * zap_vma_ptes - remove ptes mapping the vma
+ * @vma: vm_area_struct holding ptes to be zapped
+ * @address: starting address of pages to zap
+ * @size: number of bytes to zap
+ *
+ * This function only unmaps ptes assigned to VM_PFNMAP vmas.
+ *
+ * The entire address range must be fully contained within the vma.
+ *
+ * Returns 0 if successful.
+ */
+int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
+ unsigned long size)
+{
+ if (address < vma->vm_start || address + size > vma->vm_end ||
+ !(vma->vm_flags & VM_PFNMAP))
+ return -1;
+ zap_page_range(vma, address, size, NULL);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(zap_vma_ptes);
+
/*
* Do a quick page-table lookup for a single page.
*/
goto no_page_table;
pud = pud_offset(pgd, address);
- if (pud_none(*pud) || unlikely(pud_bad(*pud)))
+ if (pud_none(*pud))
goto no_page_table;
-
- pmd = pmd_offset(pud, address);
- if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+ if (pud_huge(*pud)) {
+ BUG_ON(flags & FOLL_GET);
+ page = follow_huge_pud(mm, address, pud, flags & FOLL_WRITE);
+ goto out;
+ }
+ if (unlikely(pud_bad(*pud)))
goto no_page_table;
+ pmd = pmd_offset(pud, address);
+ if (pmd_none(*pmd))
+ goto no_page_table;
if (pmd_huge(*pmd)) {
BUG_ON(flags & FOLL_GET);
page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE);
goto out;
}
+ if (unlikely(pmd_bad(*pmd)))
+ goto no_page_table;
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (!ptep)
- goto out;
pte = *ptep;
if (!pte_present(pte))
- goto unlock;
+ goto no_page;
if ((flags & FOLL_WRITE) && !pte_write(pte))
goto unlock;
page = vm_normal_page(vma, address, pte);
if (unlikely(!page))
- goto unlock;
+ goto bad_page;
if (flags & FOLL_GET)
get_page(page);
out:
return page;
+bad_page:
+ pte_unmap_unlock(ptep, ptl);
+ return ERR_PTR(-EFAULT);
+
+no_page:
+ pte_unmap_unlock(ptep, ptl);
+ if (!pte_none(pte))
+ return page;
+ /* Fall through to ZERO_PAGE handling */
no_page_table:
/*
* When core dumping an enormous anonymous area that nobody
* has touched so far, we don't want to allocate page tables.
*/
if (flags & FOLL_ANON) {
- page = ZERO_PAGE(address);
+ page = ZERO_PAGE(0);
if (flags & FOLL_GET)
get_page(page);
BUG_ON(flags & FOLL_WRITE);
return page;
}
+/* Can we do the FOLL_ANON optimization? */
+static inline int use_zero_page(struct vm_area_struct *vma)
+{
+ /*
+ * We don't want to optimize FOLL_ANON for make_pages_present()
+ * when it tries to page in a VM_LOCKED region. As to VM_SHARED,
+ * we want to get the page from the page tables to make sure
+ * that we serialize and update with any other user of that
+ * mapping.
+ */
+ if (vma->vm_flags & (VM_LOCKED | VM_SHARED))
+ return 0;
+ /*
+ * And if we have a fault routine, it's not an anonymous region.
+ */
+ return !vma->vm_ops || !vma->vm_ops->fault;
+}
+
int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, int len, int write, int force,
struct page **pages, struct vm_area_struct **vmas)
int i;
unsigned int vm_flags;
+ if (len <= 0)
+ return 0;
/*
* Require read or write permissions.
* If 'force' is set, we only require the "MAY" flags.
if (is_vm_hugetlb_page(vma)) {
i = follow_hugetlb_page(mm, vma, pages, vmas,
- &start, &len, i);
+ &start, &len, i, write);
continue;
}
foll_flags = FOLL_TOUCH;
if (pages)
foll_flags |= FOLL_GET;
- if (!write && !(vma->vm_flags & VM_LOCKED) &&
- (!vma->vm_ops || !vma->vm_ops->nopage))
+ if (!write && use_zero_page(vma))
foll_flags |= FOLL_ANON;
do {
struct page *page;
+ /*
+ * If tsk is ooming, cut off its access to large memory
+ * allocations. It has a pending SIGKILL, but it can't
+ * be processed until returning to user space.
+ */
+ if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE)))
+ return i ? i : -ENOMEM;
+
if (write)
foll_flags |= FOLL_WRITE;
cond_resched();
while (!(page = follow_page(vma, start, foll_flags))) {
int ret;
- ret = __handle_mm_fault(mm, vma, start,
+ ret = handle_mm_fault(mm, vma, start,
foll_flags & FOLL_WRITE);
+ if (ret & VM_FAULT_ERROR) {
+ if (ret & VM_FAULT_OOM)
+ return i ? i : -ENOMEM;
+ else if (ret & VM_FAULT_SIGBUS)
+ return i ? i : -EFAULT;
+ BUG();
+ }
+ if (ret & VM_FAULT_MAJOR)
+ tsk->maj_flt++;
+ else
+ tsk->min_flt++;
+
/*
- * The VM_FAULT_WRITE bit tells us that do_wp_page has
- * broken COW when necessary, even if maybe_mkwrite
- * decided not to set pte_write. We can thus safely do
- * subsequent page lookups as if they were reads.
+ * The VM_FAULT_WRITE bit tells us that
+ * do_wp_page has broken COW when necessary,
+ * even if maybe_mkwrite decided not to set
+ * pte_write. We can thus safely do subsequent
+ * page lookups as if they were reads.
*/
if (ret & VM_FAULT_WRITE)
foll_flags &= ~FOLL_WRITE;
-
- switch (ret & ~VM_FAULT_WRITE) {
- case VM_FAULT_MINOR:
- tsk->min_flt++;
- break;
- case VM_FAULT_MAJOR:
- tsk->maj_flt++;
- break;
- case VM_FAULT_SIGBUS:
- return i ? i : -EFAULT;
- case VM_FAULT_OOM:
- return i ? i : -ENOMEM;
- default:
- BUG();
- }
+
cond_resched();
}
+ if (IS_ERR(page))
+ return i ? i : PTR_ERR(page);
if (pages) {
pages[i] = page;
}
EXPORT_SYMBOL(get_user_pages);
-static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd,
- unsigned long addr, unsigned long end, pgprot_t prot)
-{
- pte_t *pte;
- spinlock_t *ptl;
- int err = 0;
-
- pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
- if (!pte)
- return -EAGAIN;
- arch_enter_lazy_mmu_mode();
- do {
- struct page *page = ZERO_PAGE(addr);
- pte_t zero_pte = pte_wrprotect(mk_pte(page, prot));
-
- if (unlikely(!pte_none(*pte))) {
- err = -EEXIST;
- pte++;
- break;
- }
- page_cache_get(page);
- page_add_file_rmap(page);
- inc_mm_counter(mm, file_rss);
- set_pte_at(mm, addr, pte, zero_pte);
- } while (pte++, addr += PAGE_SIZE, addr != end);
- arch_leave_lazy_mmu_mode();
- pte_unmap_unlock(pte - 1, ptl);
- return err;
-}
-
-static inline int zeromap_pmd_range(struct mm_struct *mm, pud_t *pud,
- unsigned long addr, unsigned long end, pgprot_t prot)
-{
- pmd_t *pmd;
- unsigned long next;
- int err;
-
- pmd = pmd_alloc(mm, pud, addr);
- if (!pmd)
- return -EAGAIN;
- do {
- next = pmd_addr_end(addr, end);
- err = zeromap_pte_range(mm, pmd, addr, next, prot);
- if (err)
- break;
- } while (pmd++, addr = next, addr != end);
- return err;
-}
-
-static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd,
- unsigned long addr, unsigned long end, pgprot_t prot)
-{
- pud_t *pud;
- unsigned long next;
- int err;
-
- pud = pud_alloc(mm, pgd, addr);
- if (!pud)
- return -EAGAIN;
- do {
- next = pud_addr_end(addr, end);
- err = zeromap_pmd_range(mm, pud, addr, next, prot);
- if (err)
- break;
- } while (pud++, addr = next, addr != end);
- return err;
-}
-
-int zeromap_page_range(struct vm_area_struct *vma,
- unsigned long addr, unsigned long size, pgprot_t prot)
-{
- pgd_t *pgd;
- unsigned long next;
- unsigned long end = addr + size;
- struct mm_struct *mm = vma->vm_mm;
- int err;
-
- BUG_ON(addr >= end);
- pgd = pgd_offset(mm, addr);
- flush_cache_range(vma, addr, end);
- do {
- next = pgd_addr_end(addr, end);
- err = zeromap_pud_range(mm, pgd, addr, next, prot);
- if (err)
- break;
- } while (pgd++, addr = next, addr != end);
- return err;
-}
-
-pte_t * fastcall get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl)
+pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
+ spinlock_t **ptl)
{
pgd_t * pgd = pgd_offset(mm, addr);
pud_t * pud = pud_alloc(mm, pgd, addr);
* old drivers should use this, and they needed to mark their
* pages reserved for the old functions anyway.
*/
-static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)
+static int insert_page(struct vm_area_struct *vma, unsigned long addr,
+ struct page *page, pgprot_t prot)
{
+ struct mm_struct *mm = vma->vm_mm;
int retval;
pte_t *pte;
- spinlock_t *ptl;
+ spinlock_t *ptl;
+
+ retval = mem_cgroup_charge(page, mm, GFP_KERNEL);
+ if (retval)
+ goto out;
retval = -EINVAL;
if (PageAnon(page))
- goto out;
+ goto out_uncharge;
retval = -ENOMEM;
flush_dcache_page(page);
pte = get_locked_pte(mm, addr, &ptl);
if (!pte)
- goto out;
+ goto out_uncharge;
retval = -EBUSY;
if (!pte_none(*pte))
goto out_unlock;
set_pte_at(mm, addr, pte, mk_pte(page, prot));
retval = 0;
+ pte_unmap_unlock(pte, ptl);
+ return retval;
out_unlock:
pte_unmap_unlock(pte, ptl);
+out_uncharge:
+ mem_cgroup_uncharge_page(page);
out:
return retval;
}
*
* The page does not need to be reserved.
*/
-int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *page)
+int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
+ struct page *page)
{
if (addr < vma->vm_start || addr >= vma->vm_end)
return -EFAULT;
if (!page_count(page))
return -EINVAL;
vma->vm_flags |= VM_INSERTPAGE;
- return insert_page(vma->vm_mm, addr, page, vma->vm_page_prot);
+ return insert_page(vma, addr, page, vma->vm_page_prot);
}
EXPORT_SYMBOL(vm_insert_page);
+static int insert_pfn(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn, pgprot_t prot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int retval;
+ pte_t *pte, entry;
+ spinlock_t *ptl;
+
+ retval = -ENOMEM;
+ pte = get_locked_pte(mm, addr, &ptl);
+ if (!pte)
+ goto out;
+ retval = -EBUSY;
+ if (!pte_none(*pte))
+ goto out_unlock;
+
+ /* Ok, finally just insert the thing.. */
+ entry = pte_mkspecial(pfn_pte(pfn, prot));
+ set_pte_at(mm, addr, pte, entry);
+ update_mmu_cache(vma, addr, entry); /* XXX: why not for insert_page? */
+
+ retval = 0;
+out_unlock:
+ pte_unmap_unlock(pte, ptl);
+out:
+ return retval;
+}
+
+/**
+ * vm_insert_pfn - insert single pfn into user vma
+ * @vma: user vma to map to
+ * @addr: target user address of this page
+ * @pfn: source kernel pfn
+ *
+ * Similar to vm_inert_page, this allows drivers to insert individual pages
+ * they've allocated into a user vma. Same comments apply.
+ *
+ * This function should only be called from a vm_ops->fault handler, and
+ * in that case the handler should return NULL.
+ *
+ * vma cannot be a COW mapping.
+ *
+ * As this is called only for pages that do not currently exist, we
+ * do not need to flush old virtual caches or the TLB.
+ */
+int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn)
+{
+ /*
+ * Technically, architectures with pte_special can avoid all these
+ * restrictions (same for remap_pfn_range). However we would like
+ * consistency in testing and feature parity among all, so we should
+ * try to keep these invariants in place for everybody.
+ */
+ BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+ BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
+ (VM_PFNMAP|VM_MIXEDMAP));
+ BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
+ BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
+
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+ return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_insert_pfn);
+
+int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn)
+{
+ BUG_ON(!(vma->vm_flags & VM_MIXEDMAP));
+
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+
+ /*
+ * If we don't have pte special, then we have to use the pfn_valid()
+ * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
+ * refcount the page if pfn_valid is true (hence insert_page rather
+ * than insert_pfn).
+ */
+ if (!HAVE_PTE_SPECIAL && pfn_valid(pfn)) {
+ struct page *page;
+
+ page = pfn_to_page(pfn);
+ return insert_page(vma, addr, page, vma->vm_page_prot);
+ }
+ return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+}
+EXPORT_SYMBOL(vm_insert_mixed);
+
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
arch_enter_lazy_mmu_mode();
do {
BUG_ON(!pte_none(*pte));
- set_pte_at(mm, addr, pte, pfn_pte(pfn, prot));
+ set_pte_at(mm, addr, pte, pte_mkspecial(pfn_pte(pfn, prot)));
pfn++;
} while (pte++, addr += PAGE_SIZE, addr != end);
arch_leave_lazy_mmu_mode();
}
EXPORT_SYMBOL(remap_pfn_range);
-/*
- * handle_pte_fault chooses page fault handler according to an entry
- * which was read non-atomically. Before making any commitment, on
- * those architectures or configurations (e.g. i386 with PAE) which
- * might give a mix of unmatched parts, do_swap_page and do_file_page
- * must check under lock before unmapping the pte and proceeding
- * (but do_wp_page is only called after already making such a check;
- * and do_anonymous_page and do_no_page can safely check later on).
- */
-static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
- pte_t *page_table, pte_t orig_pte)
+static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
{
- int same = 1;
-#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
- if (sizeof(pte_t) > sizeof(unsigned long)) {
- spinlock_t *ptl = pte_lockptr(mm, pmd);
- spin_lock(ptl);
- same = pte_same(*page_table, orig_pte);
- spin_unlock(ptl);
- }
-#endif
- pte_unmap(page_table);
- return same;
-}
+ pte_t *pte;
+ int err;
+ pgtable_t token;
+ spinlock_t *uninitialized_var(ptl);
-/*
- * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
- * servicing faults for write access. In the normal case, do always want
- * pte_mkwrite. But get_user_pages can cause write faults for mappings
- * that do not have writing enabled, when used by access_process_vm.
- */
+ pte = (mm == &init_mm) ?
+ pte_alloc_kernel(pmd, addr) :
+ pte_alloc_map_lock(mm, pmd, addr, &ptl);
+ if (!pte)
+ return -ENOMEM;
+
+ BUG_ON(pmd_huge(*pmd));
+
+ token = pmd_pgtable(*pmd);
+
+ do {
+ err = fn(pte, token, addr, data);
+ if (err)
+ break;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+
+ if (mm != &init_mm)
+ pte_unmap_unlock(pte-1, ptl);
+ return err;
+}
+
+static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pmd_t *pmd;
+ unsigned long next;
+ int err;
+
+ BUG_ON(pud_huge(*pud));
+
+ pmd = pmd_alloc(mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+ err = apply_to_pte_range(mm, pmd, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pmd++, addr = next, addr != end);
+ return err;
+}
+
+static int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pud_t *pud;
+ unsigned long next;
+ int err;
+
+ pud = pud_alloc(mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ err = apply_to_pmd_range(mm, pud, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pud++, addr = next, addr != end);
+ return err;
+}
+
+/*
+ * Scan a region of virtual memory, filling in page tables as necessary
+ * and calling a provided function on each leaf page table.
+ */
+int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
+ unsigned long size, pte_fn_t fn, void *data)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long start = addr, end = addr + size;
+ int err;
+
+ BUG_ON(addr >= end);
+ mmu_notifier_invalidate_range_start(mm, start, end);
+ pgd = pgd_offset(mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = apply_to_pud_range(mm, pgd, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+ mmu_notifier_invalidate_range_end(mm, start, end);
+ return err;
+}
+EXPORT_SYMBOL_GPL(apply_to_page_range);
+
+/*
+ * handle_pte_fault chooses page fault handler according to an entry
+ * which was read non-atomically. Before making any commitment, on
+ * those architectures or configurations (e.g. i386 with PAE) which
+ * might give a mix of unmatched parts, do_swap_page and do_file_page
+ * must check under lock before unmapping the pte and proceeding
+ * (but do_wp_page is only called after already making such a check;
+ * and do_anonymous_page and do_no_page can safely check later on).
+ */
+static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
+ pte_t *page_table, pte_t orig_pte)
+{
+ int same = 1;
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
+ if (sizeof(pte_t) > sizeof(unsigned long)) {
+ spinlock_t *ptl = pte_lockptr(mm, pmd);
+ spin_lock(ptl);
+ same = pte_same(*page_table, orig_pte);
+ spin_unlock(ptl);
+ }
+#endif
+ pte_unmap(page_table);
+ return same;
+}
+
+/*
+ * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
+ * servicing faults for write access. In the normal case, do always want
+ * pte_mkwrite. But get_user_pages can cause write faults for mappings
+ * that do not have writing enabled, when used by access_process_vm.
+ */
static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
{
if (likely(vma->vm_flags & VM_WRITE))
memset(kaddr, 0, PAGE_SIZE);
kunmap_atomic(kaddr, KM_USER0);
flush_dcache_page(dst);
- return;
-
- }
- copy_user_highpage(dst, src, va, vma);
+ } else
+ copy_user_highpage(dst, src, va, vma);
}
/*
{
struct page *old_page, *new_page;
pte_t entry;
- int reuse = 0, ret = VM_FAULT_MINOR;
+ int reuse = 0, ret = 0;
+ int page_mkwrite = 0;
struct page *dirty_page = NULL;
old_page = vm_normal_page(vma, address, orig_pte);
- if (!old_page)
+ if (!old_page) {
+ /*
+ * VM_MIXEDMAP !pfn_valid() case
+ *
+ * We should not cow pages in a shared writeable mapping.
+ * Just mark the pages writable as we can't do any dirty
+ * accounting on raw pfn maps.
+ */
+ if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+ (VM_WRITE|VM_SHARED))
+ goto reuse;
goto gotten;
+ }
/*
* Take out anonymous pages first, anonymous shared vmas are
* not dirty accountable.
*/
if (PageAnon(old_page)) {
- if (!TestSetPageLocked(old_page)) {
+ if (trylock_page(old_page)) {
reuse = can_share_swap_page(old_page);
unlock_page(old_page);
}
if (vma->vm_ops->page_mkwrite(vma, old_page) < 0)
goto unwritable_page;
- page_cache_release(old_page);
-
/*
* Since we dropped the lock we need to revalidate
* the PTE as someone else may have changed it. If
*/
page_table = pte_offset_map_lock(mm, pmd, address,
&ptl);
+ page_cache_release(old_page);
if (!pte_same(*page_table, orig_pte))
goto unlock;
+
+ page_mkwrite = 1;
}
dirty_page = old_page;
get_page(dirty_page);
}
if (reuse) {
+reuse:
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);
ret |= VM_FAULT_WRITE;
goto unlock;
}
if (unlikely(anon_vma_prepare(vma)))
goto oom;
- if (old_page == ZERO_PAGE(address)) {
- new_page = alloc_zeroed_user_highpage(vma, address);
- if (!new_page)
- goto oom;
- } else {
- new_page = alloc_page_vma(GFP_HIGHUSER, vma, address);
- if (!new_page)
- goto oom;
- cow_user_page(new_page, old_page, address, vma);
- }
+ VM_BUG_ON(old_page == ZERO_PAGE(0));
+ new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+ if (!new_page)
+ goto oom;
+ cow_user_page(new_page, old_page, address, vma);
+ __SetPageUptodate(new_page);
+
+ if (mem_cgroup_charge(new_page, mm, GFP_KERNEL))
+ goto oom_free_new;
/*
* Re-check the pte - we dropped the lock
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
if (likely(pte_same(*page_table, orig_pte))) {
if (old_page) {
- page_remove_rmap(old_page, vma);
if (!PageAnon(old_page)) {
dec_mm_counter(mm, file_rss);
inc_mm_counter(mm, anon_rss);
flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- lazy_mmu_prot_update(entry);
/*
* Clear the pte entry and flush it first, before updating the
* pte with the new entry. This will avoid a race condition
* seen in the presence of one thread doing SMC and another
* thread doing COW.
*/
- ptep_clear_flush(vma, address, page_table);
+ ptep_clear_flush_notify(vma, address, page_table);
set_pte_at(mm, address, page_table, entry);
update_mmu_cache(vma, address, entry);
lru_cache_add_active(new_page);
page_add_new_anon_rmap(new_page, vma, address);
+ if (old_page) {
+ /*
+ * Only after switching the pte to the new page may
+ * we remove the mapcount here. Otherwise another
+ * process may come and find the rmap count decremented
+ * before the pte is switched to the new page, and
+ * "reuse" the old page writing into it while our pte
+ * here still points into it and can be read by other
+ * threads.
+ *
+ * The critical issue is to order this
+ * page_remove_rmap with the ptp_clear_flush above.
+ * Those stores are ordered by (if nothing else,)
+ * the barrier present in the atomic_add_negative
+ * in page_remove_rmap.
+ *
+ * Then the TLB flush in ptep_clear_flush ensures that
+ * no process can access the old page before the
+ * decremented mapcount is visible. And the old page
+ * cannot be reused until after the decremented
+ * mapcount is visible. So transitively, TLBs to
+ * old page will be flushed before it can be reused.
+ */
+ page_remove_rmap(old_page, vma);
+ }
+
/* Free the old page.. */
new_page = old_page;
ret |= VM_FAULT_WRITE;
- }
+ } else
+ mem_cgroup_uncharge_page(new_page);
+
if (new_page)
page_cache_release(new_page);
if (old_page)
unlock:
pte_unmap_unlock(page_table, ptl);
if (dirty_page) {
- set_page_dirty_balance(dirty_page);
+ if (vma->vm_file)
+ file_update_time(vma->vm_file);
+
+ /*
+ * Yes, Virginia, this is actually required to prevent a race
+ * with clear_page_dirty_for_io() from clearing the page dirty
+ * bit after it clear all dirty ptes, but before a racing
+ * do_wp_page installs a dirty pte.
+ *
+ * do_no_page is protected similarly.
+ */
+ wait_on_page_locked(dirty_page);
+ set_page_dirty_balance(dirty_page, page_mkwrite);
put_page(dirty_page);
}
return ret;
+oom_free_new:
+ page_cache_release(new_page);
oom:
if (old_page)
page_cache_release(old_page);
unsigned long restart_addr;
int need_break;
+ /*
+ * files that support invalidating or truncating portions of the
+ * file from under mmaped areas must have their ->fault function
+ * return a locked page (and set VM_FAULT_LOCKED in the return).
+ * This provides synchronisation against concurrent unmapping here.
+ */
+
again:
restart_addr = vma->vm_truncate_count;
if (is_restart_addr(restart_addr) && start_addr < restart_addr) {
restart_addr = zap_page_range(vma, start_addr,
end_addr - start_addr, details);
- need_break = need_resched() ||
- need_lockbreak(details->i_mmap_lock);
+ need_break = need_resched() || spin_needbreak(details->i_mmap_lock);
if (restart_addr >= end_addr) {
/* We have now completed this vma: mark it so */
}
/**
- * unmap_mapping_range - unmap the portion of all mmaps
- * in the specified address_space corresponding to the specified
- * page range in the underlying file.
+ * unmap_mapping_range - unmap the portion of all mmaps in the specified address_space corresponding to the specified page range in the underlying file.
* @mapping: the address space containing mmaps to be unmapped.
* @holebegin: byte in first page to unmap, relative to the start of
* the underlying file. This will be rounded down to a PAGE_SIZE
spin_lock(&mapping->i_mmap_lock);
- /* serialize i_size write against truncate_count write */
- smp_wmb();
- /* Protect against page faults, and endless unmapping loops */
+ /* Protect against endless unmapping loops */
mapping->truncate_count++;
- /*
- * For archs where spin_lock has inclusive semantics like ia64
- * this smp_mb() will prevent to read pagetable contents
- * before the truncate_count increment is visible to
- * other cpus.
- */
- smp_mb();
if (unlikely(is_restart_addr(mapping->truncate_count))) {
if (mapping->truncate_count == 0)
reset_vma_truncate_counts(mapping);
*/
int vmtruncate(struct inode * inode, loff_t offset)
{
- struct address_space *mapping = inode->i_mapping;
- unsigned long limit;
+ if (inode->i_size < offset) {
+ unsigned long limit;
+
+ limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+ if (limit != RLIM_INFINITY && offset > limit)
+ goto out_sig;
+ if (offset > inode->i_sb->s_maxbytes)
+ goto out_big;
+ i_size_write(inode, offset);
+ } else {
+ struct address_space *mapping = inode->i_mapping;
+
+ /*
+ * truncation of in-use swapfiles is disallowed - it would
+ * cause subsequent swapout to scribble on the now-freed
+ * blocks.
+ */
+ if (IS_SWAPFILE(inode))
+ return -ETXTBSY;
+ i_size_write(inode, offset);
+
+ /*
+ * unmap_mapping_range is called twice, first simply for
+ * efficiency so that truncate_inode_pages does fewer
+ * single-page unmaps. However after this first call, and
+ * before truncate_inode_pages finishes, it is possible for
+ * private pages to be COWed, which remain after
+ * truncate_inode_pages finishes, hence the second
+ * unmap_mapping_range call must be made for correctness.
+ */
+ unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
+ truncate_inode_pages(mapping, offset);
+ unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
+ }
- if (inode->i_size < offset)
- goto do_expand;
- /*
- * truncation of in-use swapfiles is disallowed - it would cause
- * subsequent swapout to scribble on the now-freed blocks.
- */
- if (IS_SWAPFILE(inode))
- goto out_busy;
- i_size_write(inode, offset);
- unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
- truncate_inode_pages(mapping, offset);
- goto out_truncate;
-
-do_expand:
- limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
- if (limit != RLIM_INFINITY && offset > limit)
- goto out_sig;
- if (offset > inode->i_sb->s_maxbytes)
- goto out_big;
- i_size_write(inode, offset);
-
-out_truncate:
if (inode->i_op && inode->i_op->truncate)
inode->i_op->truncate(inode);
return 0;
+
out_sig:
send_sig(SIGXFSZ, current, 0);
out_big:
return -EFBIG;
-out_busy:
- return -ETXTBSY;
}
EXPORT_SYMBOL(vmtruncate);
down_write(&inode->i_alloc_sem);
unmap_mapping_range(mapping, offset, (end - offset), 1);
truncate_inode_pages_range(mapping, offset, end);
+ unmap_mapping_range(mapping, offset, (end - offset), 1);
inode->i_op->truncate_range(inode, offset, end);
up_write(&inode->i_alloc_sem);
mutex_unlock(&inode->i_mutex);
return 0;
}
-/**
- * swapin_readahead - swap in pages in hope we need them soon
- * @entry: swap entry of this memory
- * @addr: address to start
- * @vma: user vma this addresses belong to
- *
- * Primitive swap readahead code. We simply read an aligned block of
- * (1 << page_cluster) entries in the swap area. This method is chosen
- * because it doesn't cost us any seek time. We also make sure to queue
- * the 'original' request together with the readahead ones...
- *
- * This has been extended to use the NUMA policies from the mm triggering
- * the readahead.
- *
- * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
- */
-void swapin_readahead(swp_entry_t entry, unsigned long addr,struct vm_area_struct *vma)
-{
-#ifdef CONFIG_NUMA
- struct vm_area_struct *next_vma = vma ? vma->vm_next : NULL;
-#endif
- int i, num;
- struct page *new_page;
- unsigned long offset;
-
- /*
- * Get the number of handles we should do readahead io to.
- */
- num = valid_swaphandles(entry, &offset);
- for (i = 0; i < num; offset++, i++) {
- /* Ok, do the async read-ahead now */
- new_page = read_swap_cache_async(swp_entry(swp_type(entry),
- offset), vma, addr);
- if (!new_page)
- break;
- page_cache_release(new_page);
-#ifdef CONFIG_NUMA
- /*
- * Find the next applicable VMA for the NUMA policy.
- */
- addr += PAGE_SIZE;
- if (addr == 0)
- vma = NULL;
- if (vma) {
- if (addr >= vma->vm_end) {
- vma = next_vma;
- next_vma = vma ? vma->vm_next : NULL;
- }
- if (vma && addr < vma->vm_start)
- vma = NULL;
- } else {
- if (next_vma && addr >= next_vma->vm_start) {
- vma = next_vma;
- next_vma = vma->vm_next;
- }
- }
-#endif
- }
- lru_add_drain(); /* Push any new pages onto the LRU now */
-}
-
/*
* We enter with non-exclusive mmap_sem (to exclude vma changes,
* but allow concurrent faults), and pte mapped but not yet locked.
struct page *page;
swp_entry_t entry;
pte_t pte;
- int ret = VM_FAULT_MINOR;
+ int ret = 0;
if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
goto out;
page = lookup_swap_cache(entry);
if (!page) {
grab_swap_token(); /* Contend for token _before_ read-in */
- swapin_readahead(entry, address, vma);
- page = read_swap_cache_async(entry, vma, address);
+ page = swapin_readahead(entry,
+ GFP_HIGHUSER_MOVABLE, vma, address);
if (!page) {
/*
* Back out if somebody else faulted in this pte
count_vm_event(PGMAJFAULT);
}
- delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ ret = VM_FAULT_OOM;
+ goto out;
+ }
+
mark_page_accessed(page);
lock_page(page);
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
/*
* Back out if somebody else already faulted in this pte.
unlock_page(page);
if (write_access) {
- if (do_wp_page(mm, vma, address,
- page_table, pmd, ptl, pte) == VM_FAULT_OOM)
- ret = VM_FAULT_OOM;
+ ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte);
+ if (ret & VM_FAULT_ERROR)
+ ret &= VM_FAULT_ERROR;
goto out;
}
/* No need to invalidate - it was non-present before */
update_mmu_cache(vma, address, pte);
- lazy_mmu_prot_update(pte);
unlock:
pte_unmap_unlock(page_table, ptl);
out:
return ret;
out_nomap:
+ mem_cgroup_uncharge_page(page);
pte_unmap_unlock(page_table, ptl);
unlock_page(page);
page_cache_release(page);
spinlock_t *ptl;
pte_t entry;
- if (write_access) {
- /* Allocate our own private page. */
- pte_unmap(page_table);
+ /* Allocate our own private page. */
+ pte_unmap(page_table);
- if (unlikely(anon_vma_prepare(vma)))
- goto oom;
- page = alloc_zeroed_user_highpage(vma, address);
- if (!page)
- goto oom;
+ if (unlikely(anon_vma_prepare(vma)))
+ goto oom;
+ page = alloc_zeroed_user_highpage_movable(vma, address);
+ if (!page)
+ goto oom;
+ __SetPageUptodate(page);
- entry = mk_pte(page, vma->vm_page_prot);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ if (mem_cgroup_charge(page, mm, GFP_KERNEL))
+ goto oom_free_page;
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
- if (!pte_none(*page_table))
- goto release;
- inc_mm_counter(mm, anon_rss);
- lru_cache_add_active(page);
- page_add_new_anon_rmap(page, vma, address);
- } else {
- /* Map the ZERO_PAGE - vm_page_prot is readonly */
- page = ZERO_PAGE(address);
- page_cache_get(page);
- entry = mk_pte(page, vma->vm_page_prot);
-
- ptl = pte_lockptr(mm, pmd);
- spin_lock(ptl);
- if (!pte_none(*page_table))
- goto release;
- inc_mm_counter(mm, file_rss);
- page_add_file_rmap(page);
- }
+ entry = mk_pte(page, vma->vm_page_prot);
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (!pte_none(*page_table))
+ goto release;
+ inc_mm_counter(mm, anon_rss);
+ lru_cache_add_active(page);
+ page_add_new_anon_rmap(page, vma, address);
set_pte_at(mm, address, page_table, entry);
/* No need to invalidate - it was non-present before */
update_mmu_cache(vma, address, entry);
- lazy_mmu_prot_update(entry);
unlock:
pte_unmap_unlock(page_table, ptl);
- return VM_FAULT_MINOR;
+ return 0;
release:
+ mem_cgroup_uncharge_page(page);
page_cache_release(page);
goto unlock;
+oom_free_page:
+ page_cache_release(page);
oom:
return VM_FAULT_OOM;
}
/*
- * do_no_page() tries to create a new page mapping. It aggressively
+ * __do_fault() tries to create a new page mapping. It aggressively
* tries to share with existing pages, but makes a separate copy if
- * the "write_access" parameter is true in order to avoid the next
- * page fault.
+ * the FAULT_FLAG_WRITE is set in the flags parameter in order to avoid
+ * the next page fault.
*
* As this is called only for pages that do not currently exist, we
* do not need to flush old virtual caches or the TLB.
*
* We enter with non-exclusive mmap_sem (to exclude vma changes,
- * but allow concurrent faults), and pte mapped but not yet locked.
+ * but allow concurrent faults), and pte neither mapped nor locked.
* We return with mmap_sem still held, but pte unmapped and unlocked.
*/
-static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table, pmd_t *pmd,
- int write_access)
+static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmd,
+ pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
{
+ pte_t *page_table;
spinlock_t *ptl;
- struct page *new_page;
- struct address_space *mapping = NULL;
+ struct page *page;
pte_t entry;
- unsigned int sequence = 0;
- int ret = VM_FAULT_MINOR;
int anon = 0;
struct page *dirty_page = NULL;
+ struct vm_fault vmf;
+ int ret;
+ int page_mkwrite = 0;
- pte_unmap(page_table);
- BUG_ON(vma->vm_flags & VM_PFNMAP);
+ vmf.virtual_address = (void __user *)(address & PAGE_MASK);
+ vmf.pgoff = pgoff;
+ vmf.flags = flags;
+ vmf.page = NULL;
+
+ ret = vma->vm_ops->fault(vma, &vmf);
+ if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
+ return ret;
- if (vma->vm_file) {
- mapping = vma->vm_file->f_mapping;
- sequence = mapping->truncate_count;
- smp_rmb(); /* serializes i_size against truncate_count */
- }
-retry:
- new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
/*
- * No smp_rmb is needed here as long as there's a full
- * spin_lock/unlock sequence inside the ->nopage callback
- * (for the pagecache lookup) that acts as an implicit
- * smp_mb() and prevents the i_size read to happen
- * after the next truncate_count read.
+ * For consistency in subsequent calls, make the faulted page always
+ * locked.
*/
-
- /* no page was available -- either SIGBUS, OOM or REFAULT */
- if (unlikely(new_page == NOPAGE_SIGBUS))
- return VM_FAULT_SIGBUS;
- else if (unlikely(new_page == NOPAGE_OOM))
- return VM_FAULT_OOM;
- else if (unlikely(new_page == NOPAGE_REFAULT))
- return VM_FAULT_MINOR;
+ if (unlikely(!(ret & VM_FAULT_LOCKED)))
+ lock_page(vmf.page);
+ else
+ VM_BUG_ON(!PageLocked(vmf.page));
/*
* Should we do an early C-O-W break?
*/
- if (write_access) {
+ page = vmf.page;
+ if (flags & FAULT_FLAG_WRITE) {
if (!(vma->vm_flags & VM_SHARED)) {
- struct page *page;
-
- if (unlikely(anon_vma_prepare(vma)))
- goto oom;
- page = alloc_page_vma(GFP_HIGHUSER, vma, address);
- if (!page)
- goto oom;
- copy_user_highpage(page, new_page, address, vma);
- page_cache_release(new_page);
- new_page = page;
anon = 1;
-
+ if (unlikely(anon_vma_prepare(vma))) {
+ ret = VM_FAULT_OOM;
+ goto out;
+ }
+ page = alloc_page_vma(GFP_HIGHUSER_MOVABLE,
+ vma, address);
+ if (!page) {
+ ret = VM_FAULT_OOM;
+ goto out;
+ }
+ copy_user_highpage(page, vmf.page, address, vma);
+ __SetPageUptodate(page);
} else {
- /* if the page will be shareable, see if the backing
+ /*
+ * If the page will be shareable, see if the backing
* address space wants to know that the page is about
- * to become writable */
- if (vma->vm_ops->page_mkwrite &&
- vma->vm_ops->page_mkwrite(vma, new_page) < 0
- ) {
- page_cache_release(new_page);
- return VM_FAULT_SIGBUS;
+ * to become writable
+ */
+ if (vma->vm_ops->page_mkwrite) {
+ unlock_page(page);
+ if (vma->vm_ops->page_mkwrite(vma, page) < 0) {
+ ret = VM_FAULT_SIGBUS;
+ anon = 1; /* no anon but release vmf.page */
+ goto out_unlocked;
+ }
+ lock_page(page);
+ /*
+ * XXX: this is not quite right (racy vs
+ * invalidate) to unlock and relock the page
+ * like this, however a better fix requires
+ * reworking page_mkwrite locking API, which
+ * is better done later.
+ */
+ if (!page->mapping) {
+ ret = 0;
+ anon = 1; /* no anon but release vmf.page */
+ goto out;
+ }
+ page_mkwrite = 1;
}
}
+
}
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
- /*
- * For a file-backed vma, someone could have truncated or otherwise
- * invalidated this page. If unmap_mapping_range got called,
- * retry getting the page.
- */
- if (mapping && unlikely(sequence != mapping->truncate_count)) {
- pte_unmap_unlock(page_table, ptl);
- page_cache_release(new_page);
- cond_resched();
- sequence = mapping->truncate_count;
- smp_rmb();
- goto retry;
+ if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
+ ret = VM_FAULT_OOM;
+ goto out;
}
+ page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+
/*
* This silly early PAGE_DIRTY setting removes a race
* due to the bad i386 page protection. But it's valid
* handle that later.
*/
/* Only go through if we didn't race with anybody else... */
- if (pte_none(*page_table)) {
- flush_icache_page(vma, new_page);
- entry = mk_pte(new_page, vma->vm_page_prot);
- if (write_access)
+ if (likely(pte_same(*page_table, orig_pte))) {
+ flush_icache_page(vma, page);
+ entry = mk_pte(page, vma->vm_page_prot);
+ if (flags & FAULT_FLAG_WRITE)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
set_pte_at(mm, address, page_table, entry);
if (anon) {
- inc_mm_counter(mm, anon_rss);
- lru_cache_add_active(new_page);
- page_add_new_anon_rmap(new_page, vma, address);
+ inc_mm_counter(mm, anon_rss);
+ lru_cache_add_active(page);
+ page_add_new_anon_rmap(page, vma, address);
} else {
inc_mm_counter(mm, file_rss);
- page_add_file_rmap(new_page);
- if (write_access) {
- dirty_page = new_page;
+ page_add_file_rmap(page);
+ if (flags & FAULT_FLAG_WRITE) {
+ dirty_page = page;
get_page(dirty_page);
}
}
+
+ /* no need to invalidate: a not-present page won't be cached */
+ update_mmu_cache(vma, address, entry);
} else {
- /* One of our sibling threads was faster, back out. */
- page_cache_release(new_page);
- goto unlock;
+ mem_cgroup_uncharge_page(page);
+ if (anon)
+ page_cache_release(page);
+ else
+ anon = 1; /* no anon but release faulted_page */
}
- /* no need to invalidate: a not-present page shouldn't be cached */
- update_mmu_cache(vma, address, entry);
- lazy_mmu_prot_update(entry);
-unlock:
pte_unmap_unlock(page_table, ptl);
- if (dirty_page) {
- set_page_dirty_balance(dirty_page);
+
+out:
+ unlock_page(vmf.page);
+out_unlocked:
+ if (anon)
+ page_cache_release(vmf.page);
+ else if (dirty_page) {
+ if (vma->vm_file)
+ file_update_time(vma->vm_file);
+
+ set_page_dirty_balance(dirty_page, page_mkwrite);
put_page(dirty_page);
}
+
return ret;
-oom:
- page_cache_release(new_page);
- return VM_FAULT_OOM;
}
-/*
- * do_no_pfn() tries to create a new page mapping for a page without
- * a struct_page backing it
- *
- * As this is called only for pages that do not currently exist, we
- * do not need to flush old virtual caches or the TLB.
- *
- * We enter with non-exclusive mmap_sem (to exclude vma changes,
- * but allow concurrent faults), and pte mapped but not yet locked.
- * We return with mmap_sem still held, but pte unmapped and unlocked.
- *
- * It is expected that the ->nopfn handler always returns the same pfn
- * for a given virtual mapping.
- *
- * Mark this `noinline' to prevent it from bloating the main pagefault code.
- */
-static noinline int do_no_pfn(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *page_table, pmd_t *pmd,
- int write_access)
+static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *page_table, pmd_t *pmd,
+ int write_access, pte_t orig_pte)
{
- spinlock_t *ptl;
- pte_t entry;
- unsigned long pfn;
- int ret = VM_FAULT_MINOR;
+ pgoff_t pgoff = (((address & PAGE_MASK)
+ - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0);
pte_unmap(page_table);
- BUG_ON(!(vma->vm_flags & VM_PFNMAP));
- BUG_ON(is_cow_mapping(vma->vm_flags));
-
- pfn = vma->vm_ops->nopfn(vma, address & PAGE_MASK);
- if (pfn == NOPFN_OOM)
- return VM_FAULT_OOM;
- if (pfn == NOPFN_SIGBUS)
- return VM_FAULT_SIGBUS;
-
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
-
- /* Only go through if we didn't race with anybody else... */
- if (pte_none(*page_table)) {
- entry = pfn_pte(pfn, vma->vm_page_prot);
- if (write_access)
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- set_pte_at(mm, address, page_table, entry);
- }
- pte_unmap_unlock(page_table, ptl);
- return ret;
+ return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
}
/*
* but allow concurrent faults), and pte mapped but not yet locked.
* We return with mmap_sem still held, but pte unmapped and unlocked.
*/
-static int do_file_page(struct mm_struct *mm, struct vm_area_struct *vma,
+static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
int write_access, pte_t orig_pte)
{
+ unsigned int flags = FAULT_FLAG_NONLINEAR |
+ (write_access ? FAULT_FLAG_WRITE : 0);
pgoff_t pgoff;
- int err;
if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
- return VM_FAULT_MINOR;
+ return 0;
- if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) {
+ if (unlikely(!(vma->vm_flags & VM_NONLINEAR) ||
+ !(vma->vm_flags & VM_CAN_NONLINEAR))) {
/*
* Page table corrupted: show pte and kill process.
*/
print_bad_pte(vma, orig_pte, address);
return VM_FAULT_OOM;
}
- /* We can then assume vm->vm_ops && vma->vm_ops->populate */
pgoff = pte_to_pgoff(orig_pte);
- err = vma->vm_ops->populate(vma, address & PAGE_MASK, PAGE_SIZE,
- vma->vm_page_prot, pgoff, 0);
- if (err == -ENOMEM)
- return VM_FAULT_OOM;
- if (err)
- return VM_FAULT_SIGBUS;
- return VM_FAULT_MAJOR;
+ return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
}
/*
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) {
- if (vma->vm_ops->nopage)
- return do_no_page(mm, vma, address,
- pte, pmd,
- write_access);
- if (unlikely(vma->vm_ops->nopfn))
- return do_no_pfn(mm, vma, address, pte,
- pmd, write_access);
+ if (likely(vma->vm_ops->fault))
+ return do_linear_fault(mm, vma, address,
+ pte, pmd, write_access, entry);
}
return do_anonymous_page(mm, vma, address,
pte, pmd, write_access);
}
if (pte_file(entry))
- return do_file_page(mm, vma, address,
+ return do_nonlinear_fault(mm, vma, address,
pte, pmd, write_access, entry);
return do_swap_page(mm, vma, address,
pte, pmd, write_access, entry);
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 {
/*
* This is needed only for protection faults but the arch code
}
unlock:
pte_unmap_unlock(pte, ptl);
- return VM_FAULT_MINOR;
+ return 0;
}
/*
* By the time we get here, we already hold the mm semaphore
*/
-int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, int write_access)
{
pgd_t *pgd;
return handle_pte_fault(mm, vma, address, pte, pmd, write_access);
}
-EXPORT_SYMBOL_GPL(__handle_mm_fault);
-
#ifndef __PAGETABLE_PUD_FOLDED
/*
* Allocate page upper directory.
if (!new)
return -ENOMEM;
+ smp_wmb(); /* See comment in __pte_alloc */
+
spin_lock(&mm->page_table_lock);
if (pgd_present(*pgd)) /* Another has populated it */
- pud_free(new);
+ pud_free(mm, new);
else
pgd_populate(mm, pgd, new);
spin_unlock(&mm->page_table_lock);
return 0;
}
-#else
-/* Workaround for gcc 2.96 */
-int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
-{
- return 0;
-}
#endif /* __PAGETABLE_PUD_FOLDED */
#ifndef __PAGETABLE_PMD_FOLDED
if (!new)
return -ENOMEM;
+ smp_wmb(); /* See comment in __pte_alloc */
+
spin_lock(&mm->page_table_lock);
#ifndef __ARCH_HAS_4LEVEL_HACK
if (pud_present(*pud)) /* Another has populated it */
- pmd_free(new);
+ pmd_free(mm, new);
else
pud_populate(mm, pud, new);
#else
if (pgd_present(*pud)) /* Another has populated it */
- pmd_free(new);
+ pmd_free(mm, new);
else
pgd_populate(mm, pud, new);
#endif /* __ARCH_HAS_4LEVEL_HACK */
spin_unlock(&mm->page_table_lock);
return 0;
}
-#else
-/* Workaround for gcc 2.96 */
-int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
-{
- return 0;
-}
#endif /* __PAGETABLE_PMD_FOLDED */
int make_pages_present(unsigned long addr, unsigned long end)
vma = find_vma(current->mm, addr);
if (!vma)
- return -1;
+ return -ENOMEM;
write = (vma->vm_flags & VM_WRITE) != 0;
BUG_ON(addr >= end);
BUG_ON(end > vma->vm_end);
- len = (end+PAGE_SIZE-1)/PAGE_SIZE-addr/PAGE_SIZE;
+ len = DIV_ROUND_UP(end, PAGE_SIZE) - addr/PAGE_SIZE;
ret = get_user_pages(current, current->mm, addr,
len, write, 0, NULL, NULL);
- if (ret < 0)
+ if (ret < 0) {
+ /*
+ SUS require strange return value to mlock
+ - invalid addr generate to ENOMEM.
+ - out of memory should generate EAGAIN.
+ */
+ if (ret == -EFAULT)
+ ret = -ENOMEM;
+ else if (ret == -ENOMEM)
+ ret = -EAGAIN;
return ret;
- return ret == len ? 0 : -1;
-}
-
-/*
- * Map a vmalloc()-space virtual address to the physical page.
- */
-struct page * vmalloc_to_page(void * vmalloc_addr)
-{
- unsigned long addr = (unsigned long) vmalloc_addr;
- struct page *page = NULL;
- pgd_t *pgd = pgd_offset_k(addr);
- pud_t *pud;
- pmd_t *pmd;
- pte_t *ptep, pte;
-
- if (!pgd_none(*pgd)) {
- pud = pud_offset(pgd, addr);
- if (!pud_none(*pud)) {
- pmd = pmd_offset(pud, addr);
- if (!pmd_none(*pmd)) {
- ptep = pte_offset_map(pmd, addr);
- pte = *ptep;
- if (pte_present(pte))
- page = pte_page(pte);
- pte_unmap(ptep);
- }
- }
}
- return page;
-}
-
-EXPORT_SYMBOL(vmalloc_to_page);
-
-/*
- * Map a vmalloc()-space virtual address to the physical page frame number.
- */
-unsigned long vmalloc_to_pfn(void * vmalloc_addr)
-{
- return page_to_pfn(vmalloc_to_page(vmalloc_addr));
+ return ret == len ? 0 : -ENOMEM;
}
-EXPORT_SYMBOL(vmalloc_to_pfn);
-
#if !defined(__HAVE_ARCH_GATE_AREA)
#if defined(AT_SYSINFO_EHDR)
gate_vma.vm_end = FIXADDR_USER_END;
gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
gate_vma.vm_page_prot = __P101;
+ /*
+ * Make sure the vDSO gets into every core dump.
+ * Dumping its contents makes post-mortem fully interpretable later
+ * without matching up the same kernel and hardware config to see
+ * what PC values meant.
+ */
+ gate_vma.vm_flags |= VM_ALWAYSDUMP;
return 0;
}
__initcall(gate_vma_init);
#endif /* __HAVE_ARCH_GATE_AREA */
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+static resource_size_t follow_phys(struct vm_area_struct *vma,
+ unsigned long address, unsigned int flags,
+ unsigned long *prot)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep, pte;
+ spinlock_t *ptl;
+ resource_size_t phys_addr = 0;
+ struct mm_struct *mm = vma->vm_mm;
+
+ VM_BUG_ON(!(vma->vm_flags & (VM_IO | VM_PFNMAP)));
+
+ pgd = pgd_offset(mm, address);
+ if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+ goto no_page_table;
+
+ pud = pud_offset(pgd, address);
+ if (pud_none(*pud) || unlikely(pud_bad(*pud)))
+ goto no_page_table;
+
+ pmd = pmd_offset(pud, address);
+ if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+ goto no_page_table;
+
+ /* We cannot handle huge page PFN maps. Luckily they don't exist. */
+ if (pmd_huge(*pmd))
+ goto no_page_table;
+
+ ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (!ptep)
+ goto out;
+
+ pte = *ptep;
+ if (!pte_present(pte))
+ goto unlock;
+ if ((flags & FOLL_WRITE) && !pte_write(pte))
+ goto unlock;
+ phys_addr = pte_pfn(pte);
+ phys_addr <<= PAGE_SHIFT; /* Shift here to avoid overflow on PAE */
+
+ *prot = pgprot_val(pte_pgprot(pte));
+
+unlock:
+ pte_unmap_unlock(ptep, ptl);
+out:
+ return phys_addr;
+no_page_table:
+ return 0;
+}
+
+int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
+ void *buf, int len, int write)
+{
+ resource_size_t phys_addr;
+ unsigned long prot = 0;
+ void *maddr;
+ int offset = addr & (PAGE_SIZE-1);
+
+ if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+ return -EINVAL;
+
+ phys_addr = follow_phys(vma, addr, write, &prot);
+
+ if (!phys_addr)
+ return -EINVAL;
+
+ maddr = ioremap_prot(phys_addr, PAGE_SIZE, prot);
+ if (write)
+ memcpy_toio(maddr + offset, buf, len);
+ else
+ memcpy_fromio(buf, maddr + offset, len);
+ iounmap(maddr);
+
+ return len;
+}
+#endif
+
/*
* Access another process' address space.
* Source/target buffer must be kernel space,
{
struct mm_struct *mm;
struct vm_area_struct *vma;
- struct page *page;
void *old_buf = buf;
mm = get_task_mm(tsk);
return 0;
down_read(&mm->mmap_sem);
- /* ignore errors, just check how much was sucessfully transfered */
+ /* ignore errors, just check how much was successfully transferred */
while (len) {
int bytes, ret, offset;
void *maddr;
+ struct page *page = NULL;
ret = get_user_pages(tsk, mm, addr, 1,
write, 1, &page, &vma);
- if (ret <= 0)
- break;
-
- bytes = len;
- offset = addr & (PAGE_SIZE-1);
- if (bytes > PAGE_SIZE-offset)
- bytes = PAGE_SIZE-offset;
-
- maddr = kmap(page);
- if (write) {
- copy_to_user_page(vma, page, addr,
- maddr + offset, buf, bytes);
- set_page_dirty_lock(page);
+ if (ret <= 0) {
+ /*
+ * Check if this is a VM_IO | VM_PFNMAP VMA, which
+ * we can access using slightly different code.
+ */
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+ vma = find_vma(mm, addr);
+ if (!vma)
+ break;
+ if (vma->vm_ops && vma->vm_ops->access)
+ ret = vma->vm_ops->access(vma, addr, buf,
+ len, write);
+ if (ret <= 0)
+#endif
+ break;
+ bytes = ret;
} else {
- copy_from_user_page(vma, page, addr,
- buf, maddr + offset, bytes);
+ bytes = len;
+ offset = addr & (PAGE_SIZE-1);
+ if (bytes > PAGE_SIZE-offset)
+ bytes = PAGE_SIZE-offset;
+
+ maddr = kmap(page);
+ if (write) {
+ copy_to_user_page(vma, page, addr,
+ maddr + offset, buf, bytes);
+ set_page_dirty_lock(page);
+ } else {
+ copy_from_user_page(vma, page, addr,
+ buf, maddr + offset, bytes);
+ }
+ kunmap(page);
+ page_cache_release(page);
}
- kunmap(page);
- page_cache_release(page);
len -= bytes;
buf += bytes;
addr += bytes;
return buf - old_buf;
}
+
+/*
+ * Print the name of a VMA.
+ */
+void print_vma_addr(char *prefix, unsigned long ip)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ /*
+ * Do not print if we are in atomic
+ * contexts (in exception stacks, etc.):
+ */
+ if (preempt_count())
+ return;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, ip);
+ if (vma && vma->vm_file) {
+ struct file *f = vma->vm_file;
+ char *buf = (char *)__get_free_page(GFP_KERNEL);
+ if (buf) {
+ char *p, *s;
+
+ p = d_path(&f->f_path, buf, PAGE_SIZE);
+ if (IS_ERR(p))
+ p = "?";
+ s = strrchr(p, '/');
+ if (s)
+ p = s+1;
+ printk("%s%s[%lx+%lx]", prefix, p,
+ vma->vm_start,
+ vma->vm_end - vma->vm_start);
+ free_page((unsigned long)buf);
+ }
+ }
+ up_read(¤t->mm->mmap_sem);
+}
Code Review / linux-2.6.git / blobdiff