pagemap: fix large pages in pagemap
[pandora-kernel.git] / fs / proc / task_mmu.c
index 88717c0..ab8ccc9 100644 (file)
@@ -315,9 +315,9 @@ struct mem_size_stats {
 };
 
 static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
-                          void *private)
+                          struct mm_walk *walk)
 {
-       struct mem_size_stats *mss = private;
+       struct mem_size_stats *mss = walk->private;
        struct vm_area_struct *vma = mss->vma;
        pte_t *pte, ptent;
        spinlock_t *ptl;
@@ -365,19 +365,21 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
        return 0;
 }
 
-static struct mm_walk smaps_walk = { .pmd_entry = smaps_pte_range };
-
 static int show_smap(struct seq_file *m, void *v)
 {
        struct vm_area_struct *vma = v;
        struct mem_size_stats mss;
        int ret;
+       struct mm_walk smaps_walk = {
+               .pmd_entry = smaps_pte_range,
+               .mm = vma->vm_mm,
+               .private = &mss,
+       };
 
        memset(&mss, 0, sizeof mss);
        mss.vma = vma;
        if (vma->vm_mm && !is_vm_hugetlb_page(vma))
-               walk_page_range(vma->vm_mm, vma->vm_start, vma->vm_end,
-                               &smaps_walk, &mss);
+               walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
 
        ret = show_map(m, v);
        if (ret)
@@ -426,9 +428,9 @@ const struct file_operations proc_smaps_operations = {
 };
 
 static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
-                               unsigned long end, void *private)
+                               unsigned long end, struct mm_walk *walk)
 {
-       struct vm_area_struct *vma = private;
+       struct vm_area_struct *vma = walk->private;
        pte_t *pte, ptent;
        spinlock_t *ptl;
        struct page *page;
@@ -452,8 +454,6 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
        return 0;
 }
 
-static struct mm_walk clear_refs_walk = { .pmd_entry = clear_refs_pte_range };
-
 static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                                size_t count, loff_t *ppos)
 {
@@ -476,11 +476,17 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
                return -ESRCH;
        mm = get_task_mm(task);
        if (mm) {
+               static struct mm_walk clear_refs_walk;
+               memset(&clear_refs_walk, 0, sizeof(clear_refs_walk));
+               clear_refs_walk.pmd_entry = clear_refs_pte_range;
+               clear_refs_walk.mm = mm;
                down_read(&mm->mmap_sem);
-               for (vma = mm->mmap; vma; vma = vma->vm_next)
+               for (vma = mm->mmap; vma; vma = vma->vm_next) {
+                       clear_refs_walk.private = vma;
                        if (!is_vm_hugetlb_page(vma))
-                               walk_page_range(mm, vma->vm_start, vma->vm_end,
-                                               &clear_refs_walk, vma);
+                               walk_page_range(vma->vm_start, vma->vm_end,
+                                               &clear_refs_walk);
+               }
                flush_tlb_mm(mm);
                up_read(&mm->mmap_sem);
                mmput(mm);
@@ -496,7 +502,7 @@ const struct file_operations proc_clear_refs_operations = {
 };
 
 struct pagemapread {
-       char __user *out, *end;
+       u64 __user *out, *end;
 };
 
 #define PM_ENTRY_BYTES      sizeof(u64)
@@ -519,28 +525,18 @@ struct pagemapread {
 static int add_to_pagemap(unsigned long addr, u64 pfn,
                          struct pagemapread *pm)
 {
-       /*
-        * Make sure there's room in the buffer for an
-        * entire entry.  Otherwise, only copy part of
-        * the pfn.
-        */
-       if (pm->out + PM_ENTRY_BYTES >= pm->end) {
-               if (copy_to_user(pm->out, &pfn, pm->end - pm->out))
-                       return -EFAULT;
-               pm->out = pm->end;
-               return PM_END_OF_BUFFER;
-       }
-
        if (put_user(pfn, pm->out))
                return -EFAULT;
-       pm->out += PM_ENTRY_BYTES;
+       pm->out++;
+       if (pm->out >= pm->end)
+               return PM_END_OF_BUFFER;
        return 0;
 }
 
 static int pagemap_pte_hole(unsigned long start, unsigned long end,
-                               void *private)
+                               struct mm_walk *walk)
 {
-       struct pagemapread *pm = private;
+       struct pagemapread *pm = walk->private;
        unsigned long addr;
        int err = 0;
        for (addr = start; addr < end; addr += PAGE_SIZE) {
@@ -557,24 +553,45 @@ static u64 swap_pte_to_pagemap_entry(pte_t pte)
        return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
 }
 
+static unsigned long pte_to_pagemap_entry(pte_t pte)
+{
+       unsigned long pme = 0;
+       if (is_swap_pte(pte))
+               pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
+                       | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
+       else if (pte_present(pte))
+               pme = PM_PFRAME(pte_pfn(pte))
+                       | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
+       return pme;
+}
+
 static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
-                            void *private)
+                            struct mm_walk *walk)
 {
-       struct pagemapread *pm = private;
+       struct vm_area_struct *vma;
+       struct pagemapread *pm = walk->private;
        pte_t *pte;
        int err = 0;
 
+       /* find the first VMA at or above 'addr' */
+       vma = find_vma(walk->mm, addr);
        for (; addr != end; addr += PAGE_SIZE) {
                u64 pfn = PM_NOT_PRESENT;
-               pte = pte_offset_map(pmd, addr);
-               if (is_swap_pte(*pte))
-                       pfn = PM_PFRAME(swap_pte_to_pagemap_entry(*pte))
-                               | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
-               else if (pte_present(*pte))
-                       pfn = PM_PFRAME(pte_pfn(*pte))
-                               | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
-               /* unmap so we're not in atomic when we copy to userspace */
-               pte_unmap(pte);
+
+               /* check to see if we've left 'vma' behind
+                * and need a new, higher one */
+               if (vma && (addr >= vma->vm_end))
+                       vma = find_vma(walk->mm, addr);
+
+               /* check that 'vma' actually covers this address,
+                * and that it isn't a huge page vma */
+               if (vma && (vma->vm_start <= addr) &&
+                   !is_vm_hugetlb_page(vma)) {
+                       pte = pte_offset_map(pmd, addr);
+                       pfn = pte_to_pagemap_entry(*pte);
+                       /* unmap before userspace copy */
+                       pte_unmap(pte);
+               }
                err = add_to_pagemap(addr, pfn, pm);
                if (err)
                        return err;
@@ -634,7 +651,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
 
        ret = -EINVAL;
        /* file position must be aligned */
-       if (*ppos % PM_ENTRY_BYTES)
+       if ((*ppos % PM_ENTRY_BYTES) || (count % PM_ENTRY_BYTES))
                goto out_task;
 
        ret = 0;
@@ -664,8 +681,8 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
                goto out_pages;
        }
 
-       pm.out = buf;
-       pm.end = buf + count;
+       pm.out = (u64 *)buf;
+       pm.end = (u64 *)(buf + count);
 
        if (!ptrace_may_attach(task)) {
                ret = -EIO;
@@ -685,14 +702,14 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
                 * user buffer is tracked in "pm", and the walk
                 * will stop when we hit the end of the buffer.
                 */
-               ret = walk_page_range(mm, start_vaddr, end_vaddr,
-                                       &pagemap_walk, &pm);
+               ret = walk_page_range(start_vaddr, end_vaddr,
+                                       &pagemap_walk);
                if (ret == PM_END_OF_BUFFER)
                        ret = 0;
                /* don't need mmap_sem for these, but this looks cleaner */
-               *ppos += pm.out - buf;
+               *ppos += (char *)pm.out - buf;
                if (!ret)
-                       ret = pm.out - buf;
+                       ret = (char *)pm.out - buf;
        }
 
 out_pages: