diff options
Diffstat (limited to 'fs/proc/task_mmu.c')
| -rw-r--r-- | fs/proc/task_mmu.c | 115 |
1 files changed, 46 insertions, 69 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 183f8ff5f40..070553427dd 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -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> @@ -406,6 +407,7 @@ 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 +554,8 @@ 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 +578,8 @@ 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 +662,18 @@ 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 +708,20 @@ 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 +744,12 @@ 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(¤t->mm->mmap_sem); - ret = get_user_pages(current, current->mm, uaddr, pagecount, - 1, 0, pages, NULL); - up_read(¤t->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 +771,36 @@ 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: |