brk randomization: introduce CONFIG_COMPAT_BRK
[sfrench/cifs-2.6.git] / mm / memory.c
index 4b0144b24c123681dcd9e95e715ae56b009355d7..9d073fa0a2d02631f53ba3117e80b32efc2b9ae9 100644 (file)
@@ -82,7 +82,18 @@ void * high_memory;
 EXPORT_SYMBOL(num_physpages);
 EXPORT_SYMBOL(high_memory);
 
-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)
 {
@@ -305,7 +316,7 @@ int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
        spin_lock(&mm->page_table_lock);
        if (pmd_present(*pmd)) {        /* Another has populated it */
                pte_lock_deinit(new);
-               pte_free(new);
+               pte_free(mm, new);
        } else {
                mm->nr_ptes++;
                inc_zone_page_state(new, NR_PAGETABLE);
@@ -323,7 +334,7 @@ int __pte_alloc_kernel(pmd_t *pmd, unsigned long address)
 
        spin_lock(&init_mm.page_table_lock);
        if (pmd_present(*pmd))          /* Another has populated it */
-               pte_free_kernel(new);
+               pte_free_kernel(&init_mm, new);
        else
                pmd_populate_kernel(&init_mm, pmd, new);
        spin_unlock(&init_mm.page_table_lock);
@@ -513,8 +524,7 @@ again:
                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)) {
@@ -853,7 +863,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
                        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;
@@ -1110,7 +1120,8 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 }
 EXPORT_SYMBOL(get_user_pages);
 
-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);
@@ -1518,10 +1529,8 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
                        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);
 }
 
 /*
@@ -1630,6 +1639,7 @@ gotten:
        if (!new_page)
                goto oom;
        cow_user_page(new_page, old_page, address, vma);
+       __SetPageUptodate(new_page);
 
        /*
         * Re-check the pte - we dropped the lock
@@ -1768,8 +1778,7 @@ again:
 
        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 */
@@ -1911,50 +1920,49 @@ EXPORT_SYMBOL(unmap_mapping_range);
  */
 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;
 
-       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);
+               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);
+       }
 
-       /*
-        * 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);
-       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);
 
@@ -1982,67 +1990,6 @@ int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
        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.
@@ -2070,8 +2017,8 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
        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
@@ -2165,6 +2112,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
        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);
@@ -2265,6 +2213,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                                goto out;
                        }
                        copy_user_highpage(page, vmf.page, address, vma);
+                       __SetPageUptodate(page);
                } else {
                        /*
                         * If the page will be shareable, see if the backing
@@ -2565,7 +2514,7 @@ int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
 
        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);
@@ -2587,12 +2536,12 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
        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 */
@@ -2620,46 +2569,6 @@ int make_pages_present(unsigned long addr, unsigned long end)
        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));
-}
-
-EXPORT_SYMBOL(vmalloc_to_pfn);
-
 #if !defined(__HAVE_ARCH_GATE_AREA)
 
 #if defined(AT_SYSINFO_EHDR)
@@ -2756,3 +2665,34 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in
 
        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;
+
+       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_dentry, f->f_vfsmnt, 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(&current->mm->mmap_sem);
+}