Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6
[safe/jmp/linux-2.6] / fs / proc / task_mmu.c
index 183f8ff..47f5b14 100644 (file)
@@ -4,6 +4,7 @@
 #include <linux/seq_file.h>
 #include <linux/highmem.h>
 #include <linux/ptrace.h>
+#include <linux/slab.h>
 #include <linux/pagemap.h>
 #include <linux/mempolicy.h>
 #include <linux/swap.h>
@@ -246,25 +247,6 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
                                } else if (vma->vm_start <= mm->start_stack &&
                                           vma->vm_end >= mm->start_stack) {
                                        name = "[stack]";
-                               } else {
-                                       unsigned long stack_start;
-                                       struct proc_maps_private *pmp;
-
-                                       pmp = m->private;
-                                       stack_start = pmp->task->stack_start;
-
-                                       if (vma->vm_start <= stack_start &&
-                                           vma->vm_end >= stack_start) {
-                                               pad_len_spaces(m, len);
-                                               seq_printf(m,
-                                                "[threadstack:%08lx]",
-#ifdef CONFIG_STACK_GROWSUP
-                                                vma->vm_end - stack_start
-#else
-                                                stack_start - vma->vm_start
-#endif
-                                               );
-                                       }
                                }
                        } else {
                                name = "[vdso]";
@@ -406,6 +388,7 @@ static int show_smap(struct seq_file *m, void *v)
 
        memset(&mss, 0, sizeof mss);
        mss.vma = vma;
+       /* mmap_sem is held in m_start */
        if (vma->vm_mm && !is_vm_hugetlb_page(vma))
                walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
 
@@ -552,7 +535,8 @@ const struct file_operations proc_clear_refs_operations = {
 };
 
 struct pagemapread {
-       u64 __user *out, *end;
+       int pos, len;
+       u64 *buffer;
 };
 
 #define PM_ENTRY_BYTES      sizeof(u64)
@@ -575,10 +559,8 @@ struct pagemapread {
 static int add_to_pagemap(unsigned long addr, u64 pfn,
                          struct pagemapread *pm)
 {
-       if (put_user(pfn, pm->out))
-               return -EFAULT;
-       pm->out++;
-       if (pm->out >= pm->end)
+       pm->buffer[pm->pos++] = pfn;
+       if (pm->pos >= pm->len)
                return PM_END_OF_BUFFER;
        return 0;
 }
@@ -661,31 +643,18 @@ static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset)
        return pme;
 }
 
-static int pagemap_hugetlb_range(pte_t *pte, unsigned long addr,
-                                unsigned long end, struct mm_walk *walk)
+/* This function walks within one hugetlb entry in the single call */
+static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
+                                unsigned long addr, unsigned long end,
+                                struct mm_walk *walk)
 {
-       struct vm_area_struct *vma;
        struct pagemapread *pm = walk->private;
-       struct hstate *hs = NULL;
        int err = 0;
+       u64 pfn;
 
-       vma = find_vma(walk->mm, addr);
-       if (vma)
-               hs = hstate_vma(vma);
        for (; addr != end; addr += PAGE_SIZE) {
-               u64 pfn = PM_NOT_PRESENT;
-
-               if (vma && (addr >= vma->vm_end)) {
-                       vma = find_vma(walk->mm, addr);
-                       if (vma)
-                               hs = hstate_vma(vma);
-               }
-
-               if (vma && (vma->vm_start <= addr) && is_vm_hugetlb_page(vma)) {
-                       /* calculate pfn of the "raw" page in the hugepage. */
-                       int offset = (addr & ~huge_page_mask(hs)) >> PAGE_SHIFT;
-                       pfn = huge_pte_to_pagemap_entry(*pte, offset);
-               }
+               int offset = (addr & ~hmask) >> PAGE_SHIFT;
+               pfn = huge_pte_to_pagemap_entry(*pte, offset);
                err = add_to_pagemap(addr, pfn, pm);
                if (err)
                        return err;
@@ -720,21 +689,20 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long addr,
  * determine which areas of memory are actually mapped and llseek to
  * skip over unmapped regions.
  */
+#define PAGEMAP_WALK_SIZE      (PMD_SIZE)
 static ssize_t pagemap_read(struct file *file, char __user *buf,
                            size_t count, loff_t *ppos)
 {
        struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
-       struct page **pages, *page;
-       unsigned long uaddr, uend;
        struct mm_struct *mm;
        struct pagemapread pm;
-       int pagecount;
        int ret = -ESRCH;
        struct mm_walk pagemap_walk = {};
        unsigned long src;
        unsigned long svpfn;
        unsigned long start_vaddr;
        unsigned long end_vaddr;
+       int copied = 0;
 
        if (!task)
                goto out;
@@ -757,35 +725,12 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
        if (!mm)
                goto out_task;
 
-
-       uaddr = (unsigned long)buf & PAGE_MASK;
-       uend = (unsigned long)(buf + count);
-       pagecount = (PAGE_ALIGN(uend) - uaddr) / PAGE_SIZE;
-       ret = 0;
-       if (pagecount == 0)
-               goto out_mm;
-       pages = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
+       pm.len = PM_ENTRY_BYTES * (PAGEMAP_WALK_SIZE >> PAGE_SHIFT);
+       pm.buffer = kmalloc(pm.len, GFP_TEMPORARY);
        ret = -ENOMEM;
-       if (!pages)
+       if (!pm.buffer)
                goto out_mm;
 
-       down_read(&current->mm->mmap_sem);
-       ret = get_user_pages(current, current->mm, uaddr, pagecount,
-                            1, 0, pages, NULL);
-       up_read(&current->mm->mmap_sem);
-
-       if (ret < 0)
-               goto out_free;
-
-       if (ret != pagecount) {
-               pagecount = ret;
-               ret = -EFAULT;
-               goto out_pages;
-       }
-
-       pm.out = (u64 __user *)buf;
-       pm.end = (u64 __user *)(buf + count);
-
        pagemap_walk.pmd_entry = pagemap_pte_range;
        pagemap_walk.pte_hole = pagemap_pte_hole;
        pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
@@ -807,23 +752,36 @@ 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(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 += (char __user *)pm.out - buf;
-       if (!ret)
-               ret = (char __user *)pm.out - buf;
-
-out_pages:
-       for (; pagecount; pagecount--) {
-               page = pages[pagecount-1];
-               if (!PageReserved(page))
-                       SetPageDirty(page);
-               page_cache_release(page);
+       ret = 0;
+       while (count && (start_vaddr < end_vaddr)) {
+               int len;
+               unsigned long end;
+
+               pm.pos = 0;
+               end = start_vaddr + PAGEMAP_WALK_SIZE;
+               /* overflow ? */
+               if (end < start_vaddr || end > end_vaddr)
+                       end = end_vaddr;
+               down_read(&mm->mmap_sem);
+               ret = walk_page_range(start_vaddr, end, &pagemap_walk);
+               up_read(&mm->mmap_sem);
+               start_vaddr = end;
+
+               len = min(count, PM_ENTRY_BYTES * pm.pos);
+               if (copy_to_user(buf, pm.buffer, len)) {
+                       ret = -EFAULT;
+                       goto out_free;
+               }
+               copied += len;
+               buf += len;
+               count -= len;
        }
+       *ppos += copied;
+       if (!ret || ret == PM_END_OF_BUFFER)
+               ret = copied;
+
 out_free:
-       kfree(pages);
+       kfree(pm.buffer);
 out_mm:
        mmput(mm);
 out_task: