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authorAnton Vorontsov <avorontsov@ru.mvista.com>2009-09-23 03:49:27 +0400
committerAnton Vorontsov <avorontsov@ru.mvista.com>2009-09-23 03:49:27 +0400
commitf056878332a91ed984a116bad4e7d49aefff9e6e (patch)
tree572f4757c8e7811d45e0be0c2ae529c78fb63441 /mm/nommu.c
parent3961f7c3cf247eee5df7fabadc7a40f2deeb98f3 (diff)
parent7fa07729e439a6184bd824746d06a49cca553f15 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts: drivers/power/wm97xx_battery.c
Diffstat (limited to 'mm/nommu.c')
-rw-r--r--mm/nommu.c76
1 files changed, 57 insertions, 19 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index bf0cc762a7d2..1a4473faac48 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -33,6 +33,7 @@
#include <asm/uaccess.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
#include "internal.h"
static inline __attribute__((format(printf, 1, 2)))
@@ -56,8 +57,6 @@ void no_printk(const char *fmt, ...)
no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
#endif
-#include "internal.h"
-
void *high_memory;
struct page *mem_map;
unsigned long max_mapnr;
@@ -69,9 +68,6 @@ int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS;
int heap_stack_gap = 0;
-/* amount of vm to protect from userspace access */
-unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
-
atomic_long_t mmap_pages_allocated;
EXPORT_SYMBOL(mem_map);
@@ -173,21 +169,20 @@ unsigned int kobjsize(const void *objp)
}
int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, int nr_pages, int flags,
+ unsigned long start, int nr_pages, int foll_flags,
struct page **pages, struct vm_area_struct **vmas)
{
struct vm_area_struct *vma;
unsigned long vm_flags;
int i;
- int write = !!(flags & GUP_FLAGS_WRITE);
- int force = !!(flags & GUP_FLAGS_FORCE);
- int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
/* calculate required read or write permissions.
- * - if 'force' is set, we only require the "MAY" flags.
+ * If FOLL_FORCE is set, we only require the "MAY" flags.
*/
- vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
- vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
+ vm_flags = (foll_flags & FOLL_WRITE) ?
+ (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
+ vm_flags &= (foll_flags & FOLL_FORCE) ?
+ (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
for (i = 0; i < nr_pages; i++) {
vma = find_vma(mm, start);
@@ -195,8 +190,8 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
goto finish_or_fault;
/* protect what we can, including chardevs */
- if (vma->vm_flags & (VM_IO | VM_PFNMAP) ||
- (!ignore && !(vm_flags & vma->vm_flags)))
+ if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+ !(vm_flags & vma->vm_flags))
goto finish_or_fault;
if (pages) {
@@ -215,7 +210,6 @@ finish_or_fault:
return i ? : -EFAULT;
}
-
/*
* get a list of pages in an address range belonging to the specified process
* and indicate the VMA that covers each page
@@ -230,14 +224,35 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
int flags = 0;
if (write)
- flags |= GUP_FLAGS_WRITE;
+ flags |= FOLL_WRITE;
if (force)
- flags |= GUP_FLAGS_FORCE;
+ flags |= FOLL_FORCE;
return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
}
EXPORT_SYMBOL(get_user_pages);
+/**
+ * follow_pfn - look up PFN at a user virtual address
+ * @vma: memory mapping
+ * @address: user virtual address
+ * @pfn: location to store found PFN
+ *
+ * Only IO mappings and raw PFN mappings are allowed.
+ *
+ * Returns zero and the pfn at @pfn on success, -ve otherwise.
+ */
+int follow_pfn(struct vm_area_struct *vma, unsigned long address,
+ unsigned long *pfn)
+{
+ if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+ return -EINVAL;
+
+ *pfn = address >> PAGE_SHIFT;
+ return 0;
+}
+EXPORT_SYMBOL(follow_pfn);
+
DEFINE_RWLOCK(vmlist_lock);
struct vm_struct *vmlist;
@@ -609,6 +624,22 @@ static void put_nommu_region(struct vm_region *region)
}
/*
+ * update protection on a vma
+ */
+static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
+{
+#ifdef CONFIG_MPU
+ struct mm_struct *mm = vma->vm_mm;
+ long start = vma->vm_start & PAGE_MASK;
+ while (start < vma->vm_end) {
+ protect_page(mm, start, flags);
+ start += PAGE_SIZE;
+ }
+ update_protections(mm);
+#endif
+}
+
+/*
* add a VMA into a process's mm_struct in the appropriate place in the list
* and tree and add to the address space's page tree also if not an anonymous
* page
@@ -627,6 +658,8 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
mm->map_count++;
vma->vm_mm = mm;
+ protect_vma(vma, vma->vm_flags);
+
/* add the VMA to the mapping */
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
@@ -689,6 +722,8 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
kenter("%p", vma);
+ protect_vma(vma, 0);
+
mm->map_count--;
if (mm->mmap_cache == vma)
mm->mmap_cache = NULL;
@@ -901,6 +936,10 @@ static int validate_mmap_request(struct file *file,
if (!file->f_op->read)
capabilities &= ~BDI_CAP_MAP_COPY;
+ /* The file shall have been opened with read permission. */
+ if (!(file->f_mode & FMODE_READ))
+ return -EACCES;
+
if (flags & MAP_SHARED) {
/* do checks for writing, appending and locking */
if ((prot & PROT_WRITE) &&
@@ -1330,6 +1369,7 @@ unsigned long do_mmap_pgoff(struct file *file,
}
vma->vm_region = region;
+ add_nommu_region(region);
/* set up the mapping */
if (file && vma->vm_flags & VM_SHARED)
@@ -1339,8 +1379,6 @@ unsigned long do_mmap_pgoff(struct file *file,
if (ret < 0)
goto error_put_region;
- add_nommu_region(region);
-
/* okay... we have a mapping; now we have to register it */
result = vma->vm_start;