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mm: replace get_user_pages_unlocked() write/force parameters with gup_flags

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commit c164154f66f0c9b02673f07aa4f044f1d9c70274 upstream.

This removes the 'write' and 'force' use from get_user_pages_unlocked()
and replaces them with 'gup_flags' to make the use of FOLL_FORCE
explicit in callers as use of this flag can result in surprising
behaviour (and hence bugs) within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 4.4:
 - Also update calls from process_vm_rw_single_vec() and async_pf_execute()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lorenzo Stoakes 2016-10-13 01:20:13 +01:00 committed by Greg Kroah-Hartman
parent ff099ed774
commit 2b29980eb7
16 changed files with 31 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/mips/mm/gup.c
View File

@ -303,7 +303,7 @@ slow_irqon:
ret = get_user_pages_unlocked(current, mm, start,
(end - start) >> PAGE_SHIFT,
write, 0, pages);
pages, write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0) {

2
arch/s390/mm/gup.c
View File

@ -242,7 +242,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
start += nr << PAGE_SHIFT;
pages += nr;
ret = get_user_pages_unlocked(current, mm, start,
nr_pages - nr, write, 0, pages);
nr_pages - nr, pages, write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0)
ret = (ret < 0) ? nr : ret + nr;

3
arch/sh/mm/gup.c
View File

@ -258,7 +258,8 @@ slow_irqon:
pages += nr;
ret = get_user_pages_unlocked(current, mm, start,
(end - start) >> PAGE_SHIFT, write, 0, pages);
(end - start) >> PAGE_SHIFT, pages,
write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0) {

3
arch/sparc/mm/gup.c
View File

@ -250,7 +250,8 @@ slow:
pages += nr;
ret = get_user_pages_unlocked(current, mm, start,
(end - start) >> PAGE_SHIFT, write, 0, pages);
(end - start) >> PAGE_SHIFT, pages,
write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0) {

2
arch/x86/mm/gup.c
View File

@ -388,7 +388,7 @@ slow_irqon:
ret = get_user_pages_unlocked(current, mm, start,
(end - start) >> PAGE_SHIFT,
write, 0, pages);
pages, write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0) {

3
drivers/media/pci/ivtv/ivtv-udma.c
View File

@ -125,7 +125,8 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
/* Get user pages for DMA Xfer */
err = get_user_pages_unlocked(current, current->mm,
user_dma.uaddr, user_dma.page_count, 0, 1, dma->map);
user_dma.uaddr, user_dma.page_count, dma->map,
FOLL_FORCE);
if (user_dma.page_count != err) {
IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",

8
drivers/media/pci/ivtv/ivtv-yuv.c
View File

@ -76,13 +76,13 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma,
/* Get user pages for DMA Xfer */
y_pages = get_user_pages_unlocked(current, current->mm,
y_dma.uaddr, y_dma.page_count, 0, 1,
&dma->map[0]);
y_dma.uaddr, y_dma.page_count,
&dma->map[0], FOLL_FORCE);
uv_pages = 0; /* silence gcc. value is set and consumed only if: */
if (y_pages == y_dma.page_count) {
uv_pages = get_user_pages_unlocked(current, current->mm,
uv_dma.uaddr, uv_dma.page_count, 0, 1,
&dma->map[y_pages]);
uv_dma.uaddr, uv_dma.page_count,
&dma->map[y_pages], FOLL_FORCE);
}
if (y_pages != y_dma.page_count || uv_pages != uv_dma.page_count) {

5
drivers/scsi/st.c
View File

@ -4821,9 +4821,8 @@ static int sgl_map_user_pages(struct st_buffer *STbp,
current->mm,
uaddr,
nr_pages,
rw == READ,
0, /* don't force */
pages);
pages,
rw == READ ? FOLL_WRITE : 0); /* don't force */
/* Errors and no page mapped should return here */
if (res < nr_pages)

2
drivers/video/fbdev/pvr2fb.c
View File

@ -687,7 +687,7 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
return -ENOMEM;
ret = get_user_pages_unlocked(current, current->mm, (unsigned long)buf,
nr_pages, WRITE, 0, pages);
nr_pages, pages, FOLL_WRITE);
if (ret < nr_pages) {
nr_pages = ret;

2
include/linux/mm.h
View File

@ -1210,7 +1210,7 @@ long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
struct page **pages, unsigned int gup_flags);
long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
int write, int force, struct page **pages);
struct page **pages, unsigned int gup_flags);
int get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages);

14
mm/gup.c
View File

@ -797,17 +797,10 @@ EXPORT_SYMBOL(__get_user_pages_unlocked);
*/
long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
int write, int force, struct page **pages)
struct page **pages, unsigned int gup_flags)
{
unsigned int flags = FOLL_TOUCH;
if (write)
flags |= FOLL_WRITE;
if (force)
flags |= FOLL_FORCE;
return __get_user_pages_unlocked(tsk, mm, start, nr_pages,
pages, flags);
pages, gup_flags | FOLL_TOUCH);
}
EXPORT_SYMBOL(get_user_pages_unlocked);
@ -1427,7 +1420,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
pages += nr;
ret = get_user_pages_unlocked(current, mm, start,
nr_pages - nr, write, 0, pages);
nr_pages - nr, pages,
write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0) {

11
mm/nommu.c
View File

@ -224,17 +224,10 @@ EXPORT_SYMBOL(__get_user_pages_unlocked);
long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
int write, int force, struct page **pages)
struct page **pages, unsigned int gup_flags)
{
unsigned int flags = 0;
if (write)
flags |= FOLL_WRITE;
if (force)
flags |= FOLL_FORCE;
return __get_user_pages_unlocked(tsk, mm, start, nr_pages,
pages, flags);
pages, gup_flags);
}
EXPORT_SYMBOL(get_user_pages_unlocked);

6
mm/process_vm_access.c
View File

@ -88,19 +88,23 @@ static int process_vm_rw_single_vec(unsigned long addr,
ssize_t rc = 0;
unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
/ sizeof(struct pages *);
unsigned int flags = 0;
/* Work out address and page range required */
if (len == 0)
return 0;
nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
if (vm_write)
flags |= FOLL_WRITE;
while (!rc && nr_pages && iov_iter_count(iter)) {
int pages = min(nr_pages, max_pages_per_loop);
size_t bytes;
/* Get the pages we're interested in */
pages = get_user_pages_unlocked(task, mm, pa, pages,
vm_write, 0, process_pages);
process_pages, flags);
if (pages <= 0)
return -EFAULT;

2
mm/util.c
View File

@ -278,7 +278,7 @@ int __weak get_user_pages_fast(unsigned long start,
{
struct mm_struct *mm = current->mm;
return get_user_pages_unlocked(current, mm, start, nr_pages,
write, 0, pages);
pages, write ? FOLL_WRITE : 0);
}
EXPORT_SYMBOL_GPL(get_user_pages_fast);

2
net/ceph/pagevec.c
View File

@ -26,7 +26,7 @@ struct page **ceph_get_direct_page_vector(const void __user *data,
while (got < num_pages) {
rc = get_user_pages_unlocked(current, current->mm,
(unsigned long)data + ((unsigned long)got * PAGE_SIZE),
num_pages - got, write_page, 0, pages + got);
num_pages - got, pages + got, write_page ? FOLL_WRITE : 0);
if (rc < 0)
break;
BUG_ON(rc == 0);

2
virt/kvm/async_pf.c
View File

@ -80,7 +80,7 @@ static void async_pf_execute(struct work_struct *work)
might_sleep();
get_user_pages_unlocked(NULL, mm, addr, 1, 1, 0, NULL);
get_user_pages_unlocked(NULL, mm, addr, 1, NULL, FOLL_WRITE);
kvm_async_page_present_sync(vcpu, apf);
spin_lock(&vcpu->async_pf.lock);