Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/mm/filemap_xip.c |
| 3 | * |
| 4 | * Copyright (C) 2005 IBM Corporation |
| 5 | * Author: Carsten Otte <cotte@de.ibm.com> |
| 6 | * |
| 7 | * derived from linux/mm/filemap.c - Copyright (C) Linus Torvalds |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <linux/fs.h> |
| 12 | #include <linux/pagemap.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 13 | #include <linux/export.h> |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 14 | #include <linux/uio.h> |
| 15 | #include <linux/rmap.h> |
Andrea Arcangeli | cddb8a5 | 2008-07-28 15:46:29 -0700 | [diff] [blame] | 16 | #include <linux/mmu_notifier.h> |
Alexey Dobriyan | e8edc6e | 2007-05-21 01:22:52 +0400 | [diff] [blame] | 17 | #include <linux/sched.h> |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 18 | #include <linux/seqlock.h> |
| 19 | #include <linux/mutex.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 20 | #include <linux/gfp.h> |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 21 | #include <asm/tlbflush.h> |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 22 | #include <asm/io.h> |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 23 | |
| 24 | /* |
Carsten Otte | a76c0b9 | 2007-03-29 01:20:39 -0700 | [diff] [blame] | 25 | * We do use our own empty page to avoid interference with other users |
| 26 | * of ZERO_PAGE(), such as /dev/zero |
| 27 | */ |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 28 | static DEFINE_MUTEX(xip_sparse_mutex); |
John Stultz | 1ca7d67 | 2013-10-07 15:51:59 -0700 | [diff] [blame] | 29 | static seqcount_t xip_sparse_seq = SEQCNT_ZERO(xip_sparse_seq); |
Carsten Otte | a76c0b9 | 2007-03-29 01:20:39 -0700 | [diff] [blame] | 30 | static struct page *__xip_sparse_page; |
| 31 | |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 32 | /* called under xip_sparse_mutex */ |
Carsten Otte | a76c0b9 | 2007-03-29 01:20:39 -0700 | [diff] [blame] | 33 | static struct page *xip_sparse_page(void) |
| 34 | { |
| 35 | if (!__xip_sparse_page) { |
Akinobu Mita | c51b1a1 | 2008-01-08 15:32:57 -0800 | [diff] [blame] | 36 | struct page *page = alloc_page(GFP_HIGHUSER | __GFP_ZERO); |
| 37 | |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 38 | if (page) |
| 39 | __xip_sparse_page = page; |
Carsten Otte | a76c0b9 | 2007-03-29 01:20:39 -0700 | [diff] [blame] | 40 | } |
| 41 | return __xip_sparse_page; |
| 42 | } |
| 43 | |
| 44 | /* |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 45 | * This is a file read routine for execute in place files, and uses |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 46 | * the mapping->a_ops->get_xip_mem() function for the actual low-level |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 47 | * stuff. |
| 48 | * |
| 49 | * Note the struct file* is not used at all. It may be NULL. |
| 50 | */ |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 51 | static ssize_t |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 52 | do_xip_mapping_read(struct address_space *mapping, |
| 53 | struct file_ra_state *_ra, |
| 54 | struct file *filp, |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 55 | char __user *buf, |
| 56 | size_t len, |
| 57 | loff_t *ppos) |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 58 | { |
| 59 | struct inode *inode = mapping->host; |
Jan Kara | 2004dc8 | 2008-02-08 04:20:11 -0800 | [diff] [blame] | 60 | pgoff_t index, end_index; |
| 61 | unsigned long offset; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 62 | loff_t isize, pos; |
| 63 | size_t copied = 0, error = 0; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 64 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 65 | BUG_ON(!mapping->a_ops->get_xip_mem); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 66 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 67 | pos = *ppos; |
| 68 | index = pos >> PAGE_CACHE_SHIFT; |
| 69 | offset = pos & ~PAGE_CACHE_MASK; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 70 | |
| 71 | isize = i_size_read(inode); |
| 72 | if (!isize) |
| 73 | goto out; |
| 74 | |
| 75 | end_index = (isize - 1) >> PAGE_CACHE_SHIFT; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 76 | do { |
| 77 | unsigned long nr, left; |
| 78 | void *xip_mem; |
| 79 | unsigned long xip_pfn; |
| 80 | int zero = 0; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 81 | |
| 82 | /* nr is the maximum number of bytes to copy from this page */ |
| 83 | nr = PAGE_CACHE_SIZE; |
| 84 | if (index >= end_index) { |
| 85 | if (index > end_index) |
| 86 | goto out; |
| 87 | nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1; |
| 88 | if (nr <= offset) { |
| 89 | goto out; |
| 90 | } |
| 91 | } |
| 92 | nr = nr - offset; |
Martin Schwidefsky | 58984ce | 2009-04-02 16:56:42 -0700 | [diff] [blame] | 93 | if (nr > len - copied) |
| 94 | nr = len - copied; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 95 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 96 | error = mapping->a_ops->get_xip_mem(mapping, index, 0, |
| 97 | &xip_mem, &xip_pfn); |
| 98 | if (unlikely(error)) { |
| 99 | if (error == -ENODATA) { |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 100 | /* sparse */ |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 101 | zero = 1; |
| 102 | } else |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 103 | goto out; |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 104 | } |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 105 | |
| 106 | /* If users can be writing to this page using arbitrary |
| 107 | * virtual addresses, take care about potential aliasing |
| 108 | * before reading the page on the kernel side. |
| 109 | */ |
| 110 | if (mapping_writably_mapped(mapping)) |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 111 | /* address based flush */ ; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 112 | |
| 113 | /* |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 114 | * Ok, we have the mem, so now we can copy it to user space... |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 115 | * |
| 116 | * The actor routine returns how many bytes were actually used.. |
| 117 | * NOTE! This may not be the same as how much of a user buffer |
| 118 | * we filled up (we may be padding etc), so we can only update |
| 119 | * "pos" here (the actor routine has to update the user buffer |
| 120 | * pointers and the remaining count). |
| 121 | */ |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 122 | if (!zero) |
| 123 | left = __copy_to_user(buf+copied, xip_mem+offset, nr); |
| 124 | else |
| 125 | left = __clear_user(buf + copied, nr); |
| 126 | |
| 127 | if (left) { |
| 128 | error = -EFAULT; |
| 129 | goto out; |
| 130 | } |
| 131 | |
| 132 | copied += (nr - left); |
| 133 | offset += (nr - left); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 134 | index += offset >> PAGE_CACHE_SHIFT; |
| 135 | offset &= ~PAGE_CACHE_MASK; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 136 | } while (copied < len); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 137 | |
| 138 | out: |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 139 | *ppos = pos + copied; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 140 | if (filp) |
| 141 | file_accessed(filp); |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 142 | |
| 143 | return (copied ? copied : error); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 144 | } |
| 145 | |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 146 | ssize_t |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 147 | xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 148 | { |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 149 | if (!access_ok(VERIFY_WRITE, buf, len)) |
| 150 | return -EFAULT; |
| 151 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 152 | return do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp, |
| 153 | buf, len, ppos); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 154 | } |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 155 | EXPORT_SYMBOL_GPL(xip_file_read); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 156 | |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 157 | /* |
| 158 | * __xip_unmap is invoked from xip_unmap and |
| 159 | * xip_write |
| 160 | * |
| 161 | * This function walks all vmas of the address_space and unmaps the |
Carsten Otte | a76c0b9 | 2007-03-29 01:20:39 -0700 | [diff] [blame] | 162 | * __xip_sparse_page when found at pgoff. |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 163 | */ |
| 164 | static void |
| 165 | __xip_unmap (struct address_space * mapping, |
| 166 | unsigned long pgoff) |
| 167 | { |
| 168 | struct vm_area_struct *vma; |
| 169 | struct mm_struct *mm; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 170 | unsigned long address; |
| 171 | pte_t *pte; |
| 172 | pte_t pteval; |
Hugh Dickins | c071880 | 2005-10-29 18:16:31 -0700 | [diff] [blame] | 173 | spinlock_t *ptl; |
Hugh Dickins | 67b02f1 | 2005-10-29 18:16:31 -0700 | [diff] [blame] | 174 | struct page *page; |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 175 | unsigned count; |
| 176 | int locked = 0; |
| 177 | |
| 178 | count = read_seqcount_begin(&xip_sparse_seq); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 179 | |
Carsten Otte | a76c0b9 | 2007-03-29 01:20:39 -0700 | [diff] [blame] | 180 | page = __xip_sparse_page; |
| 181 | if (!page) |
| 182 | return; |
| 183 | |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 184 | retry: |
Peter Zijlstra | 3d48ae4 | 2011-05-24 17:12:06 -0700 | [diff] [blame] | 185 | mutex_lock(&mapping->i_mmap_mutex); |
Michel Lespinasse | 6b2dbba | 2012-10-08 16:31:25 -0700 | [diff] [blame] | 186 | vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 187 | mm = vma->vm_mm; |
| 188 | address = vma->vm_start + |
| 189 | ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); |
| 190 | BUG_ON(address < vma->vm_start || address >= vma->vm_end); |
Nick Piggin | 479db0b | 2008-08-20 14:09:18 -0700 | [diff] [blame] | 191 | pte = page_check_address(page, mm, address, &ptl, 1); |
Hugh Dickins | c071880 | 2005-10-29 18:16:31 -0700 | [diff] [blame] | 192 | if (pte) { |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 193 | /* Nuke the page table entry. */ |
Geert Uytterhoeven | 082ff0a | 2005-07-12 13:58:18 -0700 | [diff] [blame] | 194 | flush_cache_page(vma, address, pte_pfn(*pte)); |
Sagi Grimberg | 2ec74c3 | 2012-10-08 16:33:33 -0700 | [diff] [blame] | 195 | pteval = ptep_clear_flush(vma, address, pte); |
Hugh Dickins | edc315f | 2009-01-06 14:40:11 -0800 | [diff] [blame] | 196 | page_remove_rmap(page); |
KAMEZAWA Hiroyuki | d559db0 | 2010-03-05 13:41:39 -0800 | [diff] [blame] | 197 | dec_mm_counter(mm, MM_FILEPAGES); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 198 | BUG_ON(pte_dirty(pteval)); |
Hugh Dickins | c071880 | 2005-10-29 18:16:31 -0700 | [diff] [blame] | 199 | pte_unmap_unlock(pte, ptl); |
Sagi Grimberg | 2ec74c3 | 2012-10-08 16:33:33 -0700 | [diff] [blame] | 200 | /* must invalidate_page _before_ freeing the page */ |
| 201 | mmu_notifier_invalidate_page(mm, address); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 202 | page_cache_release(page); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 203 | } |
| 204 | } |
Peter Zijlstra | 3d48ae4 | 2011-05-24 17:12:06 -0700 | [diff] [blame] | 205 | mutex_unlock(&mapping->i_mmap_mutex); |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 206 | |
| 207 | if (locked) { |
| 208 | mutex_unlock(&xip_sparse_mutex); |
| 209 | } else if (read_seqcount_retry(&xip_sparse_seq, count)) { |
| 210 | mutex_lock(&xip_sparse_mutex); |
| 211 | locked = 1; |
| 212 | goto retry; |
| 213 | } |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 214 | } |
| 215 | |
| 216 | /* |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 217 | * xip_fault() is invoked via the vma operations vector for a |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 218 | * mapped memory region to read in file data during a page fault. |
| 219 | * |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 220 | * This function is derived from filemap_fault, but used for execute in place |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 221 | */ |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 222 | static int xip_file_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 223 | { |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 224 | struct file *file = vma->vm_file; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 225 | struct address_space *mapping = file->f_mapping; |
| 226 | struct inode *inode = mapping->host; |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 227 | pgoff_t size; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 228 | void *xip_mem; |
| 229 | unsigned long xip_pfn; |
| 230 | struct page *page; |
| 231 | int error; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 232 | |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 233 | /* XXX: are VM_FAULT_ codes OK? */ |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 234 | again: |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 235 | size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 236 | if (vmf->pgoff >= size) |
| 237 | return VM_FAULT_SIGBUS; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 238 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 239 | error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0, |
| 240 | &xip_mem, &xip_pfn); |
| 241 | if (likely(!error)) |
| 242 | goto found; |
| 243 | if (error != -ENODATA) |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 244 | return VM_FAULT_OOM; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 245 | |
| 246 | /* sparse block */ |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 247 | if ((vma->vm_flags & (VM_WRITE | VM_MAYWRITE)) && |
| 248 | (vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) && |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 249 | (!(mapping->host->i_sb->s_flags & MS_RDONLY))) { |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 250 | int err; |
| 251 | |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 252 | /* maybe shared writable, allocate new block */ |
Nick Piggin | 14bac5a | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 253 | mutex_lock(&xip_sparse_mutex); |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 254 | error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 1, |
| 255 | &xip_mem, &xip_pfn); |
Nick Piggin | 14bac5a | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 256 | mutex_unlock(&xip_sparse_mutex); |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 257 | if (error) |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 258 | return VM_FAULT_SIGBUS; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 259 | /* unmap sparse mappings at pgoff from all other vmas */ |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 260 | __xip_unmap(mapping, vmf->pgoff); |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 261 | |
| 262 | found: |
| 263 | err = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address, |
| 264 | xip_pfn); |
| 265 | if (err == -ENOMEM) |
| 266 | return VM_FAULT_OOM; |
Carsten Otte | 99f02ef | 2012-02-03 15:37:14 -0800 | [diff] [blame] | 267 | /* |
| 268 | * err == -EBUSY is fine, we've raced against another thread |
| 269 | * that faulted-in the same page |
| 270 | */ |
| 271 | if (err != -EBUSY) |
| 272 | BUG_ON(err); |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 273 | return VM_FAULT_NOPAGE; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 274 | } else { |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 275 | int err, ret = VM_FAULT_OOM; |
| 276 | |
| 277 | mutex_lock(&xip_sparse_mutex); |
| 278 | write_seqcount_begin(&xip_sparse_seq); |
| 279 | error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0, |
| 280 | &xip_mem, &xip_pfn); |
| 281 | if (unlikely(!error)) { |
| 282 | write_seqcount_end(&xip_sparse_seq); |
| 283 | mutex_unlock(&xip_sparse_mutex); |
| 284 | goto again; |
| 285 | } |
| 286 | if (error != -ENODATA) |
| 287 | goto out; |
Carsten Otte | a76c0b9 | 2007-03-29 01:20:39 -0700 | [diff] [blame] | 288 | /* not shared and writable, use xip_sparse_page() */ |
| 289 | page = xip_sparse_page(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 290 | if (!page) |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 291 | goto out; |
| 292 | err = vm_insert_page(vma, (unsigned long)vmf->virtual_address, |
| 293 | page); |
| 294 | if (err == -ENOMEM) |
| 295 | goto out; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 296 | |
Nick Piggin | 538f8ea6 | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 297 | ret = VM_FAULT_NOPAGE; |
| 298 | out: |
| 299 | write_seqcount_end(&xip_sparse_seq); |
| 300 | mutex_unlock(&xip_sparse_mutex); |
| 301 | |
| 302 | return ret; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 303 | } |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 304 | } |
| 305 | |
Alexey Dobriyan | f0f37e2f | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 306 | static const struct vm_operations_struct xip_file_vm_ops = { |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 307 | .fault = xip_file_fault, |
Jan Kara | 4fcf1c6 | 2012-06-12 16:20:29 +0200 | [diff] [blame] | 308 | .page_mkwrite = filemap_page_mkwrite, |
Konstantin Khlebnikov | 0b173bc | 2012-10-08 16:28:46 -0700 | [diff] [blame] | 309 | .remap_pages = generic_file_remap_pages, |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 310 | }; |
| 311 | |
| 312 | int xip_file_mmap(struct file * file, struct vm_area_struct * vma) |
| 313 | { |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 314 | BUG_ON(!file->f_mapping->a_ops->get_xip_mem); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 315 | |
| 316 | file_accessed(file); |
| 317 | vma->vm_ops = &xip_file_vm_ops; |
Konstantin Khlebnikov | 0b173bc | 2012-10-08 16:28:46 -0700 | [diff] [blame] | 318 | vma->vm_flags |= VM_MIXEDMAP; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 319 | return 0; |
| 320 | } |
| 321 | EXPORT_SYMBOL_GPL(xip_file_mmap); |
| 322 | |
| 323 | static ssize_t |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 324 | __xip_file_write(struct file *filp, const char __user *buf, |
| 325 | size_t count, loff_t pos, loff_t *ppos) |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 326 | { |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 327 | struct address_space * mapping = filp->f_mapping; |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 328 | const struct address_space_operations *a_ops = mapping->a_ops; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 329 | struct inode *inode = mapping->host; |
| 330 | long status = 0; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 331 | size_t bytes; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 332 | ssize_t written = 0; |
| 333 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 334 | BUG_ON(!mapping->a_ops->get_xip_mem); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 335 | |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 336 | do { |
| 337 | unsigned long index; |
| 338 | unsigned long offset; |
| 339 | size_t copied; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 340 | void *xip_mem; |
| 341 | unsigned long xip_pfn; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 342 | |
| 343 | offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ |
| 344 | index = pos >> PAGE_CACHE_SHIFT; |
| 345 | bytes = PAGE_CACHE_SIZE - offset; |
| 346 | if (bytes > count) |
| 347 | bytes = count; |
| 348 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 349 | status = a_ops->get_xip_mem(mapping, index, 0, |
| 350 | &xip_mem, &xip_pfn); |
| 351 | if (status == -ENODATA) { |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 352 | /* we allocate a new page unmap it */ |
Nick Piggin | 14bac5a | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 353 | mutex_lock(&xip_sparse_mutex); |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 354 | status = a_ops->get_xip_mem(mapping, index, 1, |
| 355 | &xip_mem, &xip_pfn); |
Nick Piggin | 14bac5a | 2008-08-20 14:09:20 -0700 | [diff] [blame] | 356 | mutex_unlock(&xip_sparse_mutex); |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 357 | if (!status) |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 358 | /* unmap page at pgoff from all other vmas */ |
| 359 | __xip_unmap(mapping, index); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 360 | } |
| 361 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 362 | if (status) |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 363 | break; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 364 | |
Nick Piggin | 4a9e5ef | 2007-10-16 01:24:58 -0700 | [diff] [blame] | 365 | copied = bytes - |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 366 | __copy_from_user_nocache(xip_mem + offset, buf, bytes); |
Nick Piggin | 4a9e5ef | 2007-10-16 01:24:58 -0700 | [diff] [blame] | 367 | |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 368 | if (likely(copied > 0)) { |
| 369 | status = copied; |
| 370 | |
| 371 | if (status >= 0) { |
| 372 | written += status; |
| 373 | count -= status; |
| 374 | pos += status; |
| 375 | buf += status; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 376 | } |
| 377 | } |
| 378 | if (unlikely(copied != bytes)) |
| 379 | if (status >= 0) |
| 380 | status = -EFAULT; |
| 381 | if (status < 0) |
| 382 | break; |
| 383 | } while (count); |
| 384 | *ppos = pos; |
| 385 | /* |
| 386 | * No need to use i_size_read() here, the i_size |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 387 | * cannot change under us because we hold i_mutex. |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 388 | */ |
| 389 | if (pos > inode->i_size) { |
| 390 | i_size_write(inode, pos); |
| 391 | mark_inode_dirty(inode); |
| 392 | } |
| 393 | |
| 394 | return written ? written : status; |
| 395 | } |
| 396 | |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 397 | ssize_t |
| 398 | xip_file_write(struct file *filp, const char __user *buf, size_t len, |
| 399 | loff_t *ppos) |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 400 | { |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 401 | struct address_space *mapping = filp->f_mapping; |
| 402 | struct inode *inode = mapping->host; |
| 403 | size_t count; |
| 404 | loff_t pos; |
| 405 | ssize_t ret; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 406 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 407 | mutex_lock(&inode->i_mutex); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 408 | |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 409 | if (!access_ok(VERIFY_READ, buf, len)) { |
| 410 | ret=-EFAULT; |
| 411 | goto out_up; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 412 | } |
| 413 | |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 414 | pos = *ppos; |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 415 | count = len; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 416 | |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 417 | /* We can write back this queue in page reclaim */ |
| 418 | current->backing_dev_info = mapping->backing_dev_info; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 419 | |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 420 | ret = generic_write_checks(filp, &pos, &count, S_ISBLK(inode->i_mode)); |
| 421 | if (ret) |
| 422 | goto out_backing; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 423 | if (count == 0) |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 424 | goto out_backing; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 425 | |
Miklos Szeredi | 2f1936b | 2008-06-24 16:50:14 +0200 | [diff] [blame] | 426 | ret = file_remove_suid(filp); |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 427 | if (ret) |
| 428 | goto out_backing; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 429 | |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 430 | ret = file_update_time(filp); |
| 431 | if (ret) |
| 432 | goto out_backing; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 433 | |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 434 | ret = __xip_file_write (filp, buf, count, pos, ppos); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 435 | |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 436 | out_backing: |
| 437 | current->backing_dev_info = NULL; |
| 438 | out_up: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 439 | mutex_unlock(&inode->i_mutex); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 440 | return ret; |
| 441 | } |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 442 | EXPORT_SYMBOL_GPL(xip_file_write); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 443 | |
| 444 | /* |
| 445 | * truncate a page used for execute in place |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 446 | * functionality is analog to block_truncate_page but does use get_xip_mem |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 447 | * to get the page instead of page cache |
| 448 | */ |
| 449 | int |
| 450 | xip_truncate_page(struct address_space *mapping, loff_t from) |
| 451 | { |
| 452 | pgoff_t index = from >> PAGE_CACHE_SHIFT; |
| 453 | unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| 454 | unsigned blocksize; |
| 455 | unsigned length; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 456 | void *xip_mem; |
| 457 | unsigned long xip_pfn; |
| 458 | int err; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 459 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 460 | BUG_ON(!mapping->a_ops->get_xip_mem); |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 461 | |
| 462 | blocksize = 1 << mapping->host->i_blkbits; |
| 463 | length = offset & (blocksize - 1); |
| 464 | |
| 465 | /* Block boundary? Nothing to do */ |
| 466 | if (!length) |
| 467 | return 0; |
| 468 | |
| 469 | length = blocksize - length; |
| 470 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 471 | err = mapping->a_ops->get_xip_mem(mapping, index, 0, |
| 472 | &xip_mem, &xip_pfn); |
| 473 | if (unlikely(err)) { |
| 474 | if (err == -ENODATA) |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 475 | /* Hole? No need to truncate */ |
| 476 | return 0; |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 477 | else |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 478 | return err; |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 479 | } |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 480 | memset(xip_mem + offset, 0, length); |
Carsten Otte | eb6fe0c | 2005-06-23 22:05:28 -0700 | [diff] [blame] | 481 | return 0; |
Carsten Otte | ceffc078 | 2005-06-23 22:05:25 -0700 | [diff] [blame] | 482 | } |
| 483 | EXPORT_SYMBOL_GPL(xip_truncate_page); |