*/
#include <linux/slab.h>
+#include <linux/mm.h>
#include <linux/shm.h>
#include <linux/mman.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/syscalls.h>
+#include <linux/capability.h>
#include <linux/init.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/mempolicy.h>
#include <linux/rmap.h>
+#include <linux/random.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/tlb.h>
+static void unmap_region(struct mm_struct *mm,
+ struct vm_area_struct *vma, struct vm_area_struct *prev,
+ unsigned long start, unsigned long end);
+
/*
* WARNING: the debugging will use recursive algorithms so never enable this
* unless you know what you are doing.
int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
int sysctl_overcommit_ratio = 50; /* default is 50% */
-int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
+int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
atomic_t vm_committed_space = ATOMIC_INIT(0);
-EXPORT_SYMBOL(sysctl_overcommit_memory);
-EXPORT_SYMBOL(sysctl_overcommit_ratio);
-EXPORT_SYMBOL(sysctl_max_map_count);
-EXPORT_SYMBOL(vm_committed_space);
+/*
+ * Check that a process has enough memory to allocate a new virtual
+ * mapping. 0 means there is enough memory for the allocation to
+ * succeed and -ENOMEM implies there is not.
+ *
+ * We currently support three overcommit policies, which are set via the
+ * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting
+ *
+ * Strict overcommit modes added 2002 Feb 26 by Alan Cox.
+ * Additional code 2002 Jul 20 by Robert Love.
+ *
+ * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise.
+ *
+ * Note this is a helper function intended to be used by LSMs which
+ * wish to use this logic.
+ */
+int __vm_enough_memory(long pages, int cap_sys_admin)
+{
+ unsigned long free, allowed;
+
+ vm_acct_memory(pages);
+
+ /*
+ * Sometimes we want to use more memory than we have
+ */
+ if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS)
+ return 0;
+
+ if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
+ unsigned long n;
+
+ free = get_page_cache_size();
+ free += nr_swap_pages;
+
+ /*
+ * Any slabs which are created with the
+ * SLAB_RECLAIM_ACCOUNT flag claim to have contents
+ * which are reclaimable, under pressure. The dentry
+ * cache and most inode caches should fall into this
+ */
+ free += atomic_read(&slab_reclaim_pages);
+
+ /*
+ * Leave the last 3% for root
+ */
+ if (!cap_sys_admin)
+ free -= free / 32;
+
+ if (free > pages)
+ return 0;
+
+ /*
+ * nr_free_pages() is very expensive on large systems,
+ * only call if we're about to fail.
+ */
+ n = nr_free_pages();
+
+ /*
+ * Leave reserved pages. The pages are not for anonymous pages.
+ */
+ if (n <= totalreserve_pages)
+ goto error;
+ else
+ n -= totalreserve_pages;
+
+ /*
+ * Leave the last 3% for root
+ */
+ if (!cap_sys_admin)
+ n -= n / 32;
+ free += n;
+
+ if (free > pages)
+ return 0;
+
+ goto error;
+ }
+
+ allowed = (totalram_pages - hugetlb_total_pages())
+ * sysctl_overcommit_ratio / 100;
+ /*
+ * Leave the last 3% for root
+ */
+ if (!cap_sys_admin)
+ allowed -= allowed / 32;
+ allowed += total_swap_pages;
+
+ /* Don't let a single process grow too big:
+ leave 3% of the size of this process for other processes */
+ allowed -= current->mm->total_vm / 32;
+
+ /*
+ * cast `allowed' as a signed long because vm_committed_space
+ * sometimes has a negative value
+ */
+ if (atomic_read(&vm_committed_space) < (long)allowed)
+ return 0;
+error:
+ vm_unacct_memory(pages);
+
+ return -ENOMEM;
+}
+
+EXPORT_SYMBOL(__vm_enough_memory);
/*
* Requires inode->i_mapping->i_mmap_lock
}
/*
- * Remove one vm structure and free it.
+ * Unlink a file-based vm structure from its prio_tree, to hide
+ * vma from rmap and vmtruncate before freeing its page tables.
*/
-static void remove_vm_struct(struct vm_area_struct *vma)
+void unlink_file_vma(struct vm_area_struct *vma)
{
struct file *file = vma->vm_file;
- might_sleep();
if (file) {
struct address_space *mapping = file->f_mapping;
spin_lock(&mapping->i_mmap_lock);
__remove_shared_vm_struct(vma, file, mapping);
spin_unlock(&mapping->i_mmap_lock);
}
+}
+
+/*
+ * Close a vm structure and free it, returning the next.
+ */
+static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
+{
+ struct vm_area_struct *next = vma->vm_next;
+
+ might_sleep();
if (vma->vm_ops && vma->vm_ops->close)
vma->vm_ops->close(vma);
- if (file)
- fput(file);
- anon_vma_unlink(vma);
+ if (vma->vm_file)
+ fput(vma->vm_file);
mpol_free(vma_policy(vma));
kmem_cache_free(vm_area_cachep, vma);
+ return next;
}
-/*
- * sys_brk() for the most part doesn't need the global kernel
- * lock, except when an application is doing something nasty
- * like trying to un-brk an area that has already been mapped
- * to a regular file. in this case, the unmapping will need
- * to invoke file system routines that need the global lock.
- */
asmlinkage unsigned long sys_brk(unsigned long brk)
{
unsigned long rlim, retval;
if (brk < mm->end_code)
goto out;
+
+ /*
+ * Check against rlimit here. If this check is done later after the test
+ * of oldbrk with newbrk then it can escape the test and let the data
+ * segment grow beyond its set limit the in case where the limit is
+ * not page aligned -Ram Gupta
+ */
+ rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+ if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
+ goto out;
+
newbrk = PAGE_ALIGN(brk);
oldbrk = PAGE_ALIGN(mm->brk);
if (oldbrk == newbrk)
goto out;
}
- /* Check against rlimit.. */
- rlim = current->rlim[RLIMIT_DATA].rlim_cur;
- if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
- goto out;
-
/* Check against existing mmap mappings. */
if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
goto out;
i = browse_rb(&mm->mm_rb);
if (i != mm->map_count)
printk("map_count %d rb %d\n", mm->map_count, i), bug = 1;
- if (bug)
- BUG();
+ BUG_ON(bug);
}
#else
#define validate_mm(mm) do { } while (0)
__vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct rb_node *rb_parent)
{
+ if (vma->vm_flags & VM_EXEC)
+ arch_add_exec_range(mm, vma->vm_end);
if (prev) {
vma->vm_next = prev->vm_next;
prev->vm_next = vma;
if (vma->vm_file)
mapping = vma->vm_file->f_mapping;
- if (mapping)
+ if (mapping) {
spin_lock(&mapping->i_mmap_lock);
+ vma->vm_truncate_count = mapping->truncate_count;
+ }
anon_vma_lock(vma);
__vma_link(mm, vma, prev, rb_link, rb_parent);
struct rb_node ** rb_link, * rb_parent;
__vma = find_vma_prepare(mm, vma->vm_start,&prev, &rb_link, &rb_parent);
- if (__vma && __vma->vm_start < vma->vm_end)
- BUG();
+ BUG_ON(__vma && __vma->vm_start < vma->vm_end);
__vma_link(mm, vma, prev, rb_link, rb_parent);
mm->map_count++;
}
rb_erase(&vma->vm_rb, &mm->mm_rb);
if (mm->mmap_cache == vma)
mm->mmap_cache = prev;
+ if (vma->vm_flags & VM_EXEC)
+ arch_remove_exec_range(mm, vma->vm_end);
}
/*
again: remove_next = 1 + (end > next->vm_end);
end = next->vm_end;
anon_vma = next->anon_vma;
+ importer = vma;
} else if (end > next->vm_start) {
/*
* vma expands, overlapping part of the next:
if (!(vma->vm_flags & VM_NONLINEAR))
root = &mapping->i_mmap;
spin_lock(&mapping->i_mmap_lock);
+ if (importer &&
+ vma->vm_truncate_count != next->vm_truncate_count) {
+ /*
+ * unmap_mapping_range might be in progress:
+ * ensure that the expanding vma is rescanned.
+ */
+ importer->vm_truncate_count = 0;
+ }
if (insert) {
+ insert->vm_truncate_count = vma->vm_truncate_count;
/*
* Put into prio_tree now, so instantiated pages
* are visible to arm/parisc __flush_dcache_page
* If the vma has a ->close operation then the driver probably needs to release
* per-vma resources, so we don't attempt to merge those.
*/
-#define VM_SPECIAL (VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_RESERVED)
+#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
static inline int is_mergeable_vma(struct vm_area_struct *vma,
struct file *file, unsigned long vm_flags)
} else /* cases 2, 5, 7 */
vma_adjust(prev, prev->vm_start,
end, prev->vm_pgoff, NULL);
+ if (prev->vm_flags & VM_EXEC)
+ arch_add_exec_range(mm, prev->vm_end);
return prev;
}
* (e.g. stash info in next's anon_vma_node when assigning
* an anon_vma, or when trying vma_merge). Another time.
*/
- if (find_vma_prev(vma->vm_mm, vma->vm_start, &near) != vma)
- BUG();
+ BUG_ON(find_vma_prev(vma->vm_mm, vma->vm_start, &near) != vma);
if (!near)
goto none;
}
#ifdef CONFIG_PROC_FS
-void __vm_stat_account(struct mm_struct *mm, unsigned long flags,
+void vm_stat_account(struct mm_struct *mm, unsigned long flags,
struct file *file, long pages)
{
const unsigned long stack_flags
= VM_STACK_FLAGS & (VM_GROWSUP|VM_GROWSDOWN);
-#ifdef CONFIG_HUGETLB
- if (flags & VM_HUGETLB) {
- if (!(flags & VM_DONTCOPY))
- mm->shared_vm += pages;
- return;
- }
-#endif /* CONFIG_HUGETLB */
-
- if (file)
+ if (file) {
mm->shared_vm += pages;
- else if (flags & stack_flags)
+ if ((flags & (VM_EXEC|VM_WRITE)) == VM_EXEC)
+ mm->exec_vm += pages;
+ } else if (flags & stack_flags)
mm->stack_vm += pages;
- if (flags & VM_EXEC)
- mm->exec_vm += pages;
if (flags & (VM_RESERVED|VM_IO))
mm->reserved_vm += pages;
}
int error;
struct rb_node ** rb_link, * rb_parent;
int accountable = 1;
- unsigned long charged = 0;
+ unsigned long charged = 0, reqprot = prot;
if (file) {
if (is_file_hugepages(file))
prot |= PROT_EXEC;
if (!len)
- return addr;
+ return -EINVAL;
+
+ error = arch_mmap_check(addr, len, flags);
+ if (error)
+ return error;
/* Careful about overflows.. */
len = PAGE_ALIGN(len);
if (!len || len > TASK_SIZE)
- return -EINVAL;
+ return -ENOMEM;
/* offset overflow? */
if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)
- return -EINVAL;
+ return -EOVERFLOW;
/* Too many mappings? */
if (mm->map_count > sysctl_max_map_count)
/* Obtain the address to map to. we verify (or select) it and ensure
* that it represents a valid section of the address space.
*/
- addr = get_unmapped_area(file, addr, len, pgoff, flags);
+ addr = get_unmapped_area_prot(file, addr, len, pgoff, flags, prot & PROT_EXEC);
if (addr & ~PAGE_MASK)
return addr;
/* mlock MCL_FUTURE? */
if (vm_flags & VM_LOCKED) {
unsigned long locked, lock_limit;
- locked = mm->locked_vm << PAGE_SHIFT;
- lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
- locked += len;
+ locked = len >> PAGE_SHIFT;
+ locked += mm->locked_vm;
+ lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit >>= PAGE_SHIFT;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
return -EAGAIN;
}
}
}
- error = security_file_mmap(file, prot, flags);
+ error = security_file_mmap(file, reqprot, prot, flags);
if (error)
return error;
}
/* Check against address space limit. */
- if ((mm->total_vm << PAGE_SHIFT) + len
- > current->rlim[RLIMIT_AS].rlim_cur)
- return -ENOMEM;
-
- /* check context space, maybe only Private writable mapping? */
- if (!vx_vmpages_avail(mm, len >> PAGE_SHIFT))
+ if (!may_expand_vm(mm, len >> PAGE_SHIFT))
return -ENOMEM;
if (accountable && (!(flags & MAP_NORESERVE) ||
* specific mapper. the address has already been validated, but
* not unmapped, but the maps are removed from the list.
*/
- vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+ vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (!vma) {
error = -ENOMEM;
goto unacct_error;
}
- memset(vma, 0, sizeof(*vma));
vma->vm_mm = mm;
vma->vm_start = addr;
* f_op->mmap method. -DaveM
*/
addr = vma->vm_start;
+ pgoff = vma->vm_pgoff;
+ vm_flags = vma->vm_flags;
if (!file || !vma_merge(mm, prev, addr, vma->vm_end,
vma->vm_flags, NULL, file, pgoff, vma_policy(vma))) {
+ file = vma->vm_file;
vma_link(mm, vma, prev, rb_link, rb_parent);
if (correct_wcount)
atomic_inc(&inode->i_writecount);
kmem_cache_free(vm_area_cachep, vma);
}
out:
- // mm->total_vm += len >> PAGE_SHIFT;
vx_vmpages_add(mm, len >> PAGE_SHIFT);
+ vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
if (vm_flags & VM_LOCKED) {
- // mm->locked_vm += len >> PAGE_SHIFT;
vx_vmlocked_add(mm, len >> PAGE_SHIFT);
make_pages_present(addr, addr + len);
}
pgoff, flags & MAP_NONBLOCK);
down_write(&mm->mmap_sem);
}
- __vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
return addr;
unmap_and_free_vma:
fput(file);
/* Undo any partial mapping done by a device driver. */
- zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+ unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
+ charged = 0;
free_vma:
kmem_cache_free(vm_area_cachep, vma);
unacct_error:
(!vma || addr + len <= vma->vm_start))
return addr;
}
- start_addr = addr = mm->free_area_cache;
+ if (len > mm->cached_hole_size) {
+ start_addr = addr = mm->free_area_cache;
+ } else {
+ start_addr = addr = TASK_UNMAPPED_BASE;
+ mm->cached_hole_size = 0;
+ }
full_search:
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
* some holes.
*/
if (start_addr != TASK_UNMAPPED_BASE) {
- start_addr = addr = TASK_UNMAPPED_BASE;
+ addr = TASK_UNMAPPED_BASE;
+ start_addr = addr;
+ mm->cached_hole_size = 0;
goto full_search;
}
return -ENOMEM;
mm->free_area_cache = addr + len;
return addr;
}
+ if (addr + mm->cached_hole_size < vma->vm_start)
+ mm->cached_hole_size = vma->vm_start - addr;
addr = vma->vm_end;
}
}
#endif
-void arch_unmap_area(struct vm_area_struct *area)
+void arch_unmap_area(struct mm_struct *mm, unsigned long addr)
{
/*
* Is this a new hole at the lowest possible address?
*/
- if (area->vm_start >= TASK_UNMAPPED_BASE &&
- area->vm_start < area->vm_mm->free_area_cache)
- area->vm_mm->free_area_cache = area->vm_start;
+ if (addr >= TASK_UNMAPPED_BASE && addr < mm->free_area_cache) {
+ mm->free_area_cache = addr;
+ mm->cached_hole_size = ~0UL;
+ }
}
/*
const unsigned long len, const unsigned long pgoff,
const unsigned long flags)
{
- struct vm_area_struct *vma, *prev_vma;
+ struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
- unsigned long base = mm->mmap_base, addr = addr0;
- int first_time = 1;
+ unsigned long addr = addr0;
/* requested length too big for entire address space */
if (len > TASK_SIZE)
return -ENOMEM;
- /* dont allow allocations above current base */
- if (mm->free_area_cache > base)
- mm->free_area_cache = base;
-
/* requesting a specific address */
if (addr) {
addr = PAGE_ALIGN(addr);
return addr;
}
-try_again:
+ /* check if free_area_cache is useful for us */
+ if (len <= mm->cached_hole_size) {
+ mm->cached_hole_size = 0;
+ mm->free_area_cache = mm->mmap_base;
+ }
+
+ /* either no address requested or can't fit in requested address hole */
+ addr = mm->free_area_cache;
+
/* make sure it can fit in the remaining address space */
- if (mm->free_area_cache < len)
- goto fail;
+ if (addr > len) {
+ vma = find_vma(mm, addr-len);
+ if (!vma || addr <= vma->vm_start)
+ /* remember the address as a hint for next time */
+ return (mm->free_area_cache = addr-len);
+ }
+
+ if (mm->mmap_base < len)
+ goto bottomup;
+
+ addr = mm->mmap_base-len;
- /* either no address requested or cant fit in requested address hole */
- addr = (mm->free_area_cache - len) & PAGE_MASK;
do {
/*
* Lookup failure means no vma is above this address,
- * i.e. return with success:
+ * else if new region fits below vma->vm_start,
+ * return with success:
*/
- if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
- return addr;
-
- /*
- * new region fits between prev_vma->vm_end and
- * vma->vm_start, use it:
- */
- if (addr+len <= vma->vm_start &&
- (!prev_vma || (addr >= prev_vma->vm_end)))
+ vma = find_vma(mm, addr);
+ if (!vma || addr+len <= vma->vm_start)
/* remember the address as a hint for next time */
return (mm->free_area_cache = addr);
- else
- /* pull free_area_cache down to the first hole */
- if (mm->free_area_cache == vma->vm_end)
- mm->free_area_cache = vma->vm_start;
+
+ /* remember the largest hole we saw so far */
+ if (addr + mm->cached_hole_size < vma->vm_start)
+ mm->cached_hole_size = vma->vm_start - addr;
/* try just below the current vma->vm_start */
addr = vma->vm_start-len;
- } while (len <= vma->vm_start);
+ } while (len < vma->vm_start);
-fail:
- /*
- * if hint left us with no space for the requested
- * mapping then try again:
- */
- if (first_time) {
- mm->free_area_cache = base;
- first_time = 0;
- goto try_again;
- }
+bottomup:
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
* can happen with large stack limits and large mmap()
* allocations.
*/
- mm->free_area_cache = TASK_UNMAPPED_BASE;
+ mm->cached_hole_size = ~0UL;
+ mm->free_area_cache = TASK_UNMAPPED_BASE;
addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
/*
* Restore the topdown base:
*/
- mm->free_area_cache = base;
+ mm->free_area_cache = mm->mmap_base;
+ mm->cached_hole_size = ~0UL;
return addr;
}
#endif
-void arch_unmap_area_topdown(struct vm_area_struct *area)
+void arch_unmap_area_topdown(struct mm_struct *mm, unsigned long addr)
{
/*
* Is this a new hole at the highest possible address?
*/
- if (area->vm_end > area->vm_mm->free_area_cache)
- area->vm_mm->free_area_cache = area->vm_end;
+ if (addr > mm->free_area_cache)
+ mm->free_area_cache = addr;
+
+ /* dont allow allocations above current base */
+ if (mm->free_area_cache > mm->mmap_base)
+ mm->free_area_cache = mm->mmap_base;
}
+
unsigned long
-get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
- unsigned long pgoff, unsigned long flags)
+get_unmapped_area_prot(struct file *file, unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags, int exec)
{
- if (flags & MAP_FIXED) {
- unsigned long ret;
+ unsigned long ret;
+
+ if (!(flags & MAP_FIXED)) {
+ unsigned long (*get_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
+
+ if (exec && current->mm->get_unmapped_exec_area)
+ get_area = current->mm->get_unmapped_exec_area;
+ else
+ get_area = current->mm->get_unmapped_area;
- if (addr > TASK_SIZE - len)
+ if (file && file->f_op && file->f_op->get_unmapped_area)
+ get_area = file->f_op->get_unmapped_area;
+ addr = get_area(file, addr, len, pgoff, flags);
+ if (IS_ERR_VALUE(addr))
+ return addr;
+ }
+
+ if (addr > TASK_SIZE - len)
+ return -ENOMEM;
+ if (addr & ~PAGE_MASK)
+ return -EINVAL;
+ if (file && is_file_hugepages(file)) {
+ /*
+ * Check if the given range is hugepage aligned, and
+ * can be made suitable for hugepages.
+ */
+ ret = prepare_hugepage_range(addr, len);
+ } else {
+ /*
+ * Ensure that a normal request is not falling in a
+ * reserved hugepage range. For some archs like IA-64,
+ * there is a separate region for hugepages.
+ */
+ ret = is_hugepage_only_range(current->mm, addr, len);
+ }
+ if (ret)
+ return -EINVAL;
+ return addr;
+}
+
+EXPORT_SYMBOL(get_unmapped_area_prot);
+
+#define SHLIB_BASE 0x00111000
+
+unsigned long arch_get_unmapped_exec_area(struct file *filp, unsigned long addr0,
+ unsigned long len0, unsigned long pgoff, unsigned long flags)
+{
+ unsigned long addr = addr0, len = len0;
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long tmp;
+
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (!addr && !(flags & MAP_FIXED))
+ addr = randomize_range(SHLIB_BASE, 0x01000000, len);
+
+ if (addr) {
+ addr = PAGE_ALIGN(addr);
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vma->vm_start)) {
+ return addr;
+ }
+ }
+
+ addr = SHLIB_BASE;
+ for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
+ /* At this point: (!vma || addr < vma->vm_end). */
+ if (TASK_SIZE - len < addr)
return -ENOMEM;
- if (addr & ~PAGE_MASK)
- return -EINVAL;
- if (file && is_file_hugepages(file)) {
+
+ if (!vma || addr + len <= vma->vm_start) {
/*
- * Check if the given range is hugepage aligned, and
- * can be made suitable for hugepages.
+ * Must not let a PROT_EXEC mapping get into the
+ * brk area:
*/
- ret = prepare_hugepage_range(addr, len);
- } else {
+ if (addr + len > mm->brk)
+ goto failed;
+
/*
- * Ensure that a normal request is not falling in a
- * reserved hugepage range. For some archs like IA-64,
- * there is a separate region for hugepages.
+ * Up until the brk area we randomize addresses
+ * as much as possible:
*/
- ret = is_hugepage_only_range(addr, len);
+ if (addr >= 0x01000000) {
+ tmp = randomize_range(0x01000000, PAGE_ALIGN(max(mm->start_brk, (unsigned long)0x08000000)), len);
+ vma = find_vma(mm, tmp);
+ if (TASK_SIZE - len >= tmp &&
+ (!vma || tmp + len <= vma->vm_start))
+ return tmp;
+ }
+ /*
+ * Ok, randomization didnt work out - return
+ * the result of the linear search:
+ */
+ return addr;
}
- if (ret)
- return -EINVAL;
- return addr;
+ addr = vma->vm_end;
}
- if (file && file->f_op && file->f_op->get_unmapped_area)
- return file->f_op->get_unmapped_area(file, addr, len,
- pgoff, flags);
-
- return current->mm->get_unmapped_area(file, addr, len, pgoff, flags);
+failed:
+ return current->mm->get_unmapped_area(filp, addr0, len0, pgoff, flags);
}
-EXPORT_SYMBOL(get_unmapped_area);
/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr)
return prev ? prev->vm_next : vma;
}
-#ifdef CONFIG_STACK_GROWSUP
+static int over_stack_limit(unsigned long sz)
+{
+ if (sz < EXEC_STACK_BIAS)
+ return 0;
+ return (sz - EXEC_STACK_BIAS) >
+ current->signal->rlim[RLIMIT_STACK].rlim_cur;
+}
+
/*
- * vma is the first one with address > vma->vm_end. Have to extend vma.
+ * Verify that the stack growth is acceptable and
+ * update accounting. This is shared with both the
+ * grow-up and grow-down cases.
*/
-int expand_stack(struct vm_area_struct * vma, unsigned long address)
+static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, unsigned long grow)
{
- unsigned long grow;
+ struct mm_struct *mm = vma->vm_mm;
+ struct rlimit *rlim = current->signal->rlim;
+
+ /* address space limit tests */
+ if (!may_expand_vm(mm, grow))
+ return -ENOMEM;
+
+ /* Stack limit test */
+ if (over_stack_limit(size))
+ return -ENOMEM;
+
+ /* mlock limit tests */
+ if (vma->vm_flags & VM_LOCKED) {
+ unsigned long locked;
+ unsigned long limit;
+ locked = mm->locked_vm + grow;
+ limit = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+ if (locked > limit && !capable(CAP_IPC_LOCK))
+ return -ENOMEM;
+ }
+
+ /*
+ * Overcommit.. This must be the final test, as it will
+ * update security statistics.
+ */
+ if (security_vm_enough_memory(grow))
+ return -ENOMEM;
+
+ /* Ok, everything looks good - let it rip */
+ vx_vmpages_add(mm, grow);
+ if (vma->vm_flags & VM_LOCKED)
+ vx_vmlocked_add(mm, grow);
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow);
+ return 0;
+}
+
+#if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64)
+/*
+ * PA-RISC uses this for its stack; IA64 for its Register Backing Store.
+ * vma is the last one with address > vma->vm_end. Have to extend vma.
+ */
+#ifndef CONFIG_IA64
+static inline
+#endif
+int expand_upwards(struct vm_area_struct *vma, unsigned long address)
+{
+ int error;
if (!(vma->vm_flags & VM_GROWSUP))
return -EFAULT;
*/
address += 4 + PAGE_SIZE - 1;
address &= PAGE_MASK;
- grow = (address - vma->vm_end) >> PAGE_SHIFT;
+ error = 0;
- /* Overcommit.. vx check first to avoid vm_unacct_memory() */
- if (!vx_vmpages_avail(vma->vm_mm, grow) ||
- security_vm_enough_memory(grow)) {
- anon_vma_unlock(vma);
- return -ENOMEM;
- }
-
- if (address - vma->vm_start > current->rlim[RLIMIT_STACK].rlim_cur ||
- ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
- current->rlim[RLIMIT_AS].rlim_cur) {
- anon_vma_unlock(vma);
- vm_unacct_memory(grow);
- return -ENOMEM;
+ /* Somebody else might have raced and expanded it already */
+ if (address > vma->vm_end) {
+ unsigned long size, grow;
+
+ size = address - vma->vm_start;
+ grow = (address - vma->vm_end) >> PAGE_SHIFT;
+
+ error = acct_stack_growth(vma, size, grow);
+ if (!error)
+ vma->vm_end = address;
}
- vma->vm_end = address;
- // vma->vm_mm->total_vm += grow;
- vx_vmpages_add(vma->vm_mm, grow);
- if (vma->vm_flags & VM_LOCKED)
- // vma->vm_mm->locked_vm += grow;
- vx_vmlocked_add(vma->vm_mm, grow);
- __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow);
anon_vma_unlock(vma);
- return 0;
+ return error;
+}
+#endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
+
+#ifdef CONFIG_STACK_GROWSUP
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+ return expand_upwards(vma, address);
}
struct vm_area_struct *
*/
int expand_stack(struct vm_area_struct *vma, unsigned long address)
{
- unsigned long grow;
+ int error;
/*
* We must make sure the anon_vma is allocated
* anon_vma lock to serialize against concurrent expand_stacks.
*/
address &= PAGE_MASK;
- grow = (vma->vm_start - address) >> PAGE_SHIFT;
+ error = 0;
- /* Overcommit.. vx check first to avoid vm_unacct_memory() */
- if (!vx_vmpages_avail(vma->vm_mm, grow) ||
- security_vm_enough_memory(grow)) {
- anon_vma_unlock(vma);
- return -ENOMEM;
- }
-
- if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
- ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
- current->rlim[RLIMIT_AS].rlim_cur) {
- anon_vma_unlock(vma);
- vm_unacct_memory(grow);
- return -ENOMEM;
+ /* Somebody else might have raced and expanded it already */
+ if (address < vma->vm_start) {
+ unsigned long size, grow;
+
+ size = vma->vm_end - address;
+ grow = (vma->vm_start - address) >> PAGE_SHIFT;
+
+ error = acct_stack_growth(vma, size, grow);
+ if (!error) {
+ vma->vm_start = address;
+ vma->vm_pgoff -= grow;
+ }
}
- vma->vm_start = address;
- vma->vm_pgoff -= grow;
- // vma->vm_mm->total_vm += grow;
- vx_vmpages_add(vma->vm_mm, grow);
- if (vma->vm_flags & VM_LOCKED)
- // vma->vm_mm->locked_vm += grow;
- vx_vmlocked_add(vma->vm_mm, grow);
- __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow);
anon_vma_unlock(vma);
- return 0;
+ return error;
}
struct vm_area_struct *
#endif
/*
- * Try to free as many page directory entries as we can,
- * without having to work very hard at actually scanning
- * the page tables themselves.
- *
- * Right now we try to free page tables if we have a nice
- * PGDIR-aligned area that got free'd up. We could be more
- * granular if we want to, but this is fast and simple,
- * and covers the bad cases.
- *
- * "prev", if it exists, points to a vma before the one
- * we just free'd - but there's no telling how much before.
- */
-static void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *prev,
- unsigned long start, unsigned long end)
-{
- unsigned long first = start & PGDIR_MASK;
- unsigned long last = end + PGDIR_SIZE - 1;
- unsigned long start_index, end_index;
- struct mm_struct *mm = tlb->mm;
-
- if (!prev) {
- prev = mm->mmap;
- if (!prev)
- goto no_mmaps;
- if (prev->vm_end > start) {
- if (last > prev->vm_start)
- last = prev->vm_start;
- goto no_mmaps;
- }
- }
- for (;;) {
- struct vm_area_struct *next = prev->vm_next;
-
- if (next) {
- if (next->vm_start < start) {
- prev = next;
- continue;
- }
- if (last > next->vm_start)
- last = next->vm_start;
- }
- if (prev->vm_end > first)
- first = prev->vm_end + PGDIR_SIZE - 1;
- break;
- }
-no_mmaps:
- if (last < first) /* for arches with discontiguous pgd indices */
- return;
- /*
- * If the PGD bits are not consecutive in the virtual address, the
- * old method of shifting the VA >> by PGDIR_SHIFT doesn't work.
- */
- start_index = pgd_index(first);
- if (start_index < FIRST_USER_PGD_NR)
- start_index = FIRST_USER_PGD_NR;
- end_index = pgd_index(last);
- if (end_index > start_index) {
- clear_page_tables(tlb, start_index, end_index - start_index);
- flush_tlb_pgtables(mm, first & PGDIR_MASK, last & PGDIR_MASK);
- }
-}
-
-/* Normal function to fix up a mapping
- * This function is the default for when an area has no specific
- * function. This may be used as part of a more specific routine.
- *
- * By the time this function is called, the area struct has been
- * removed from the process mapping list.
- */
-static void unmap_vma(struct mm_struct *mm, struct vm_area_struct *area)
-{
- size_t len = area->vm_end - area->vm_start;
-
- // area->vm_mm->total_vm -= len >> PAGE_SHIFT;
- vx_vmpages_sub(area->vm_mm, len >> PAGE_SHIFT);
-
- if (area->vm_flags & VM_LOCKED)
- // area->vm_mm->locked_vm -= len >> PAGE_SHIFT;
- vx_vmlocked_sub(area->vm_mm, len >> PAGE_SHIFT);
- vm_stat_unaccount(area);
- area->vm_mm->unmap_area(area);
- remove_vm_struct(area);
-}
-
-/*
- * Update the VMA and inode share lists.
- *
- * Ok - we have the memory areas we should free on the 'free' list,
+ * Ok - we have the memory areas we should free on the vma list,
* so release them, and do the vma updates.
+ *
+ * Called with the mm semaphore held.
*/
-static void unmap_vma_list(struct mm_struct *mm,
- struct vm_area_struct *mpnt)
+static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
{
+ /* Update high watermark before we lower total_vm */
+ update_hiwater_vm(mm);
do {
- struct vm_area_struct *next = mpnt->vm_next;
- unmap_vma(mm, mpnt);
- mpnt = next;
- } while (mpnt != NULL);
+ long nrpages = vma_pages(vma);
+
+ vx_vmpages_sub(mm, nrpages);
+ if (vma->vm_flags & VM_LOCKED)
+ vx_vmlocked_sub(mm, nrpages);
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages);
+ vma = remove_vma(vma);
+ } while (vma);
validate_mm(mm);
}
/*
* Get rid of page table information in the indicated region.
*
- * Called with the page table lock held.
+ * Called with the mm semaphore held.
*/
static void unmap_region(struct mm_struct *mm,
- struct vm_area_struct *vma,
- struct vm_area_struct *prev,
- unsigned long start,
- unsigned long end)
+ struct vm_area_struct *vma, struct vm_area_struct *prev,
+ unsigned long start, unsigned long end)
{
+ struct vm_area_struct *next = prev? prev->vm_next: mm->mmap;
struct mmu_gather *tlb;
unsigned long nr_accounted = 0;
lru_add_drain();
tlb = tlb_gather_mmu(mm, 0);
- unmap_vmas(&tlb, mm, vma, start, end, &nr_accounted, NULL);
+ update_hiwater_rss(mm);
+ unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
-
- if (is_hugepage_only_range(start, end - start))
- hugetlb_free_pgtables(tlb, prev, start, end);
- else
- free_pgtables(tlb, prev, start, end);
+ free_pgtables(&tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS,
+ next? next->vm_start: 0);
tlb_finish_mmu(tlb, start, end);
}
{
struct vm_area_struct **insertion_point;
struct vm_area_struct *tail_vma = NULL;
+ unsigned long addr;
insertion_point = (prev ? &prev->vm_next : &mm->mmap);
do {
} while (vma && vma->vm_start < end);
*insertion_point = vma;
tail_vma->vm_next = NULL;
+ if (mm->unmap_area == arch_unmap_area)
+ addr = prev ? prev->vm_end : mm->mmap_base;
+ else
+ addr = vma ? vma->vm_start : mm->mmap_base;
+ mm->unmap_area(mm, addr);
mm->mmap_cache = NULL; /* Kill the cache. */
}
struct mempolicy *pol;
struct vm_area_struct *new;
+ if (is_vm_hugetlb_page(vma) && (addr & ~HPAGE_MASK))
+ return -EINVAL;
+
if (mm->map_count >= sysctl_max_map_count)
return -ENOMEM;
if (new->vm_ops && new->vm_ops->open)
new->vm_ops->open(new);
- if (new_below)
+ if (new_below) {
+ unsigned long old_end = vma->vm_end;
+
vma_adjust(vma, addr, vma->vm_end, vma->vm_pgoff +
((addr - new->vm_start) >> PAGE_SHIFT), new);
- else
+ if (vma->vm_flags & VM_EXEC)
+ arch_remove_exec_range(mm, old_end);
+ } else
vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new);
return 0;
int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
{
unsigned long end;
- struct vm_area_struct *mpnt, *prev, *last;
+ struct vm_area_struct *vma, *prev, *last;
if ((start & ~PAGE_MASK) || start > TASK_SIZE || len > TASK_SIZE-start)
return -EINVAL;
return -EINVAL;
/* Find the first overlapping VMA */
- mpnt = find_vma_prev(mm, start, &prev);
- if (!mpnt)
+ vma = find_vma_prev(mm, start, &prev);
+ if (!vma)
return 0;
- /* we have start < mpnt->vm_end */
-
- if (is_vm_hugetlb_page(mpnt)) {
- int ret = is_aligned_hugepage_range(start, len);
-
- if (ret)
- return ret;
- }
+ /* we have start < vma->vm_end */
/* if it doesn't overlap, we have nothing.. */
end = start + len;
- if (mpnt->vm_start >= end)
+ if (vma->vm_start >= end)
return 0;
/*
* unmapped vm_area_struct will remain in use: so lower split_vma
* places tmp vma above, and higher split_vma places tmp vma below.
*/
- if (start > mpnt->vm_start) {
- if (split_vma(mm, mpnt, start, 0))
- return -ENOMEM;
- prev = mpnt;
+ if (start > vma->vm_start) {
+ int error = split_vma(mm, vma, start, 0);
+ if (error)
+ return error;
+ prev = vma;
}
/* Does it split the last one? */
last = find_vma(mm, end);
if (last && end > last->vm_start) {
- if (split_vma(mm, last, end, 1))
- return -ENOMEM;
+ int error = split_vma(mm, last, end, 1);
+ if (error)
+ return error;
}
- mpnt = prev? prev->vm_next: mm->mmap;
+ vma = prev? prev->vm_next: mm->mmap;
/*
* Remove the vma's, and unmap the actual pages
*/
- detach_vmas_to_be_unmapped(mm, mpnt, prev, end);
- spin_lock(&mm->page_table_lock);
- unmap_region(mm, mpnt, prev, start, end);
- spin_unlock(&mm->page_table_lock);
+ detach_vmas_to_be_unmapped(mm, vma, prev, end);
+ unmap_region(mm, vma, prev, start, end);
/* Fix up all other VM information */
- unmap_vma_list(mm, mpnt);
+ remove_vma_list(mm, vma);
return 0;
}
return ret;
}
+static inline void verify_mm_writelocked(struct mm_struct *mm)
+{
+#ifdef CONFIG_DEBUG_VM
+ if (unlikely(down_read_trylock(&mm->mmap_sem))) {
+ WARN_ON(1);
+ up_read(&mm->mmap_sem);
+ }
+#endif
+}
+
/*
* this is really a simplified "do_mmap". it only handles
* anonymous maps. eventually we may be able to do some
unsigned long flags;
struct rb_node ** rb_link, * rb_parent;
pgoff_t pgoff = addr >> PAGE_SHIFT;
+ int error;
len = PAGE_ALIGN(len);
if (!len)
if ((addr + len) > TASK_SIZE || (addr + len) < addr)
return -EINVAL;
+ flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
+
+ error = arch_mmap_check(addr, len, flags);
+ if (error)
+ return error;
+
/*
* mlock MCL_FUTURE?
*/
if (mm->def_flags & VM_LOCKED) {
unsigned long locked, lock_limit;
- locked = mm->locked_vm << PAGE_SHIFT;
- lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
- locked += len;
+ locked = len >> PAGE_SHIFT;
+ locked += mm->locked_vm;
+ lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit >>= PAGE_SHIFT;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
return -EAGAIN;
if (!vx_vmlocked_avail(mm, len >> PAGE_SHIFT))
return -ENOMEM;
}
+ /*
+ * mm->mmap_sem is required to protect against another thread
+ * changing the mappings in case we sleep.
+ */
+ verify_mm_writelocked(mm);
+
/*
* Clear old maps. this also does some error checking for us
*/
}
/* Check against address space limits *after* clearing old maps... */
- if ((mm->total_vm << PAGE_SHIFT) + len
- > current->rlim[RLIMIT_AS].rlim_cur)
+ if (!may_expand_vm(mm, len >> PAGE_SHIFT))
return -ENOMEM;
if (mm->map_count > sysctl_max_map_count)
!vx_vmpages_avail(mm, len >> PAGE_SHIFT))
return -ENOMEM;
- flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
-
/* Can we just expand an old private anonymous mapping? */
if (vma_merge(mm, prev, addr, addr + len, flags,
NULL, NULL, pgoff, NULL))
/*
* create a vma struct for an anonymous mapping
*/
- vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+ vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (!vma) {
vm_unacct_memory(len >> PAGE_SHIFT);
return -ENOMEM;
}
- memset(vma, 0, sizeof(*vma));
vma->vm_mm = mm;
vma->vm_start = addr;
vma->vm_page_prot = protection_map[flags & 0x0f];
vma_link(mm, vma, prev, rb_link, rb_parent);
out:
- // mm->total_vm += len >> PAGE_SHIFT;
vx_vmpages_add(mm, len >> PAGE_SHIFT);
if (flags & VM_LOCKED) {
- // mm->locked_vm += len >> PAGE_SHIFT;
vx_vmlocked_add(mm, len >> PAGE_SHIFT);
make_pages_present(addr, addr + len);
}
void exit_mmap(struct mm_struct *mm)
{
struct mmu_gather *tlb;
- struct vm_area_struct *vma;
+ struct vm_area_struct *vma = mm->mmap;
unsigned long nr_accounted = 0;
+ unsigned long end;
- lru_add_drain();
-
- spin_lock(&mm->page_table_lock);
+#ifdef arch_exit_mmap
+ arch_exit_mmap(mm);
+#endif
- tlb = tlb_gather_mmu(mm, 1);
+ lru_add_drain();
flush_cache_mm(mm);
- /* Use ~0UL here to ensure all VMAs in the mm are unmapped */
- mm->map_count -= unmap_vmas(&tlb, mm, mm->mmap, 0,
- ~0UL, &nr_accounted, NULL);
+ tlb = tlb_gather_mmu(mm, 1);
+ /* Don't update_hiwater_rss(mm) here, do_exit already did */
+ /* Use -1 here to ensure all VMAs in the mm are unmapped */
+ end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
- BUG_ON(mm->map_count); /* This is just debugging */
- clear_page_tables(tlb, FIRST_USER_PGD_NR, USER_PTRS_PER_PGD);
- tlb_finish_mmu(tlb, 0, MM_VM_SIZE(mm));
+ free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);
+ tlb_finish_mmu(tlb, 0, end);
+ arch_flush_exec_range(mm);
- vma = mm->mmap;
- mm->mmap = mm->mmap_cache = NULL;
- mm->mm_rb = RB_ROOT;
- // mm->rss = 0;
- vx_rsspages_sub(mm, mm->rss);
- // mm->total_vm = 0;
+ set_mm_counter(mm, file_rss, 0);
+ set_mm_counter(mm, anon_rss, 0);
vx_vmpages_sub(mm, mm->total_vm);
- // mm->locked_vm = 0;
vx_vmlocked_sub(mm, mm->locked_vm);
- spin_unlock(&mm->page_table_lock);
-
/*
- * Walk the list again, actually closing and freeing it
- * without holding any MM locks.
+ * Walk the list again, actually closing and freeing it,
+ * with preemption enabled, without holding any MM locks.
*/
- while (vma) {
- struct vm_area_struct *next = vma->vm_next;
- remove_vm_struct(vma);
- vma = next;
- }
+ while (vma)
+ vma = remove_vma(vma);
+
+ BUG_ON(mm->nr_ptes > (FIRST_USER_ADDRESS+PMD_SIZE-1)>>PMD_SHIFT);
}
/* Insert vm structure into process list sorted by address
* and into the inode's i_mmap tree. If vm_file is non-NULL
* then i_mmap_lock is taken here.
*/
-void insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma)
+int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma)
{
struct vm_area_struct * __vma, * prev;
struct rb_node ** rb_link, * rb_parent;
}
__vma = find_vma_prepare(mm,vma->vm_start,&prev,&rb_link,&rb_parent);
if (__vma && __vma->vm_start < vma->vm_end)
- BUG();
+ return -ENOMEM;
+ if ((vma->vm_flags & VM_ACCOUNT) &&
+ (security_vm_enough_memory(vma_pages(vma)) ||
+ !vx_vmpages_avail(mm, vma_pages(vma))))
+ return -ENOMEM;
vma_link(mm, vma, prev, rb_link, rb_parent);
+ return 0;
}
/*
}
return new_vma;
}
+
+/*
+ * Return true if the calling process may expand its vm space by the passed
+ * number of pages
+ */
+int may_expand_vm(struct mm_struct *mm, unsigned long npages)
+{
+ unsigned long cur = mm->total_vm; /* pages */
+ unsigned long lim;
+
+ lim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+
+ if (cur + npages > lim)
+ return 0;
+ if (!vx_vmpages_avail(mm, npages))
+ return 0;
+ return 1;
+}
+
+
+static struct page *
+special_mapping_nopage(struct vm_area_struct *vma,
+ unsigned long address, int *type)
+{
+ struct page **pages;
+
+ BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+
+ address -= vma->vm_start;
+ for (pages = vma->vm_private_data; address > 0 && *pages; ++pages)
+ address -= PAGE_SIZE;
+
+ if (*pages) {
+ get_page(*pages);
+ return *pages;
+ }
+
+ return NOPAGE_SIGBUS;
+}
+
+static struct vm_operations_struct special_mapping_vmops = {
+ .nopage = special_mapping_nopage,
+};
+
+unsigned int vdso_populate = 1;
+
+/*
+ * Insert a new vma covering the given region, with the given flags and
+ * protections. Its pages are supplied by the given null-terminated array.
+ * The region past the last page supplied will always produce SIGBUS.
+ * The array pointer and the pages it points to are assumed to stay alive
+ * for as long as this mapping might exist.
+ */
+int install_special_mapping(struct mm_struct *mm,
+ unsigned long addr, unsigned long len,
+ unsigned long vm_flags, pgprot_t pgprot,
+ struct page **pages)
+{
+ struct vm_area_struct *vma;
+ int err;
+
+ vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+ if (unlikely(vma == NULL))
+ return -ENOMEM;
+ memset(vma, 0, sizeof(*vma));
+
+ vma->vm_mm = mm;
+ vma->vm_start = addr;
+ vma->vm_end = addr + len;
+
+ vma->vm_flags = vm_flags;
+ vma->vm_page_prot = pgprot;
+
+ vma->vm_ops = &special_mapping_vmops;
+ vma->vm_private_data = pages;
+
+ insert_vm_struct(mm, vma);
+ mm->total_vm += len >> PAGE_SHIFT;
+
+ if (!vdso_populate)
+ return 0;
+
+ err = 0;
+ while (*pages) {
+ struct page *page = *pages++;
+ get_page(page);
+ err = install_page(mm, vma, addr, page, vma->vm_page_prot);
+ if (err) {
+ put_page(page);
+ break;
+ }
+ addr += PAGE_SIZE;
+ }
+
+ return err;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff