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

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>

diff --git a/arch/mips/mm/gup.c b/arch/mips/mm/gup.c
index 42d124fb6474477c896e4618713e5b6d65d6e8f3..d8c3c159289a2953b8ae495a1da34d27d095b161 100644 (file)
--- a/arch/mips/mm/gup.c
+++ b/arch/mips/mm/gup.c
@@ -287,7 +287,7 @@ slow_irqon:
        pages += nr;
 
        ret = get_user_pages_unlocked(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) {

diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
index adb0c34bf431e121d66caff904c30fb7e63e933d..18d4107e10eefb5e2ea5935412a95e7a03f2ae41 100644 (file)
--- a/arch/s390/mm/gup.c
+++ b/arch/s390/mm/gup.c
@@ -266,7 +266,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
        /* Try to get the remaining pages with get_user_pages */
        start += nr << PAGE_SHIFT;
        pages += nr;
-       ret = get_user_pages_unlocked(start, nr_pages - nr, write, 0, pages);
+       ret = get_user_pages_unlocked(start, 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;

diff --git a/arch/sh/mm/gup.c b/arch/sh/mm/gup.c
index 40fa6c8adc43a361c60ffee8929aa39d2449e926..063c298ba56cc900479eb9b50a8c9587678f6893 100644 (file)
--- a/arch/sh/mm/gup.c
+++ b/arch/sh/mm/gup.c
@@ -258,7 +258,8 @@ slow_irqon:
                pages += nr;
 
                ret = get_user_pages_unlocked(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) {

diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c
index 4e06750a5d295649660ff4ca0998eb03b00da9e9..cd0e32bbcb1de0f6b16bce4ccd3f8b89acaa18b9 100644 (file)
--- a/arch/sparc/mm/gup.c
+++ b/arch/sparc/mm/gup.c
@@ -238,7 +238,8 @@ slow:
                pages += nr;
 
                ret = get_user_pages_unlocked(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) {

diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index b8b6a60b32cf47837070518bd44d4c4742910697..0d4fb3ebbbac9872aaaf26514211ae543a253299 100644 (file)
--- a/arch/x86/mm/gup.c
+++ b/arch/x86/mm/gup.c
@@ -435,7 +435,7 @@ slow_irqon:
 
                ret = get_user_pages_unlocked(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) {

diff --git a/drivers/media/pci/ivtv/ivtv-udma.c b/drivers/media/pci/ivtv/ivtv-udma.c
index 4769469fe842964574eae3a72b812f579ab5f63f..2c9232ef7baa4b57efd020547d0b2af3f42199d4 100644 (file)
--- a/drivers/media/pci/ivtv/ivtv-udma.c
+++ b/drivers/media/pci/ivtv/ivtv-udma.c
@@ -124,8 +124,8 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
        }
 
        /* Get user pages for DMA Xfer */
-       err = get_user_pages_unlocked(user_dma.uaddr, user_dma.page_count, 0,
-                       1, dma->map);
+       err = get_user_pages_unlocked(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",

diff --git a/drivers/media/pci/ivtv/ivtv-yuv.c b/drivers/media/pci/ivtv/ivtv-yuv.c
index b094054cda6e55b64852598d6d22dd6d57e6cdaa..f7299d3d82449ddaefc1ee76fd3f8cb33650e5b4 100644 (file)
--- a/drivers/media/pci/ivtv/ivtv-yuv.c
+++ b/drivers/media/pci/ivtv/ivtv-yuv.c
@@ -76,11 +76,12 @@ 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(y_dma.uaddr,
-                       y_dma.page_count, 0, 1, &dma->map[0]);
+                       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(uv_dma.uaddr,
-                               uv_dma.page_count, 0, 1, &dma->map[y_pages]);
+                               uv_dma.page_count, &dma->map[y_pages],
+                               FOLL_FORCE);
        }
 
        if (y_pages != y_dma.page_count || uv_pages != uv_dma.page_count) {

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 7af5226aa55ba0937b69b8b0f2d5d070f3eccf7d..618422ea3a4123d8d0b115f8811634e8225de8a1 100644 (file)
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4922,9 +4922,8 @@ static int sgl_map_user_pages(struct st_buffer *STbp,
        res = get_user_pages_unlocked(
                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)

diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c
index 3b1ca441107370d39c54bd4bffa24248eaa730c5..a2564ab91e62d3c2775441d292e54e1d25492a40 100644 (file)
--- a/drivers/video/fbdev/pvr2fb.c
+++ b/drivers/video/fbdev/pvr2fb.c
@@ -686,8 +686,8 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
        if (!pages)
                return -ENOMEM;
 
-       ret = get_user_pages_unlocked((unsigned long)buf, nr_pages, WRITE,
-                       0, pages);
+       ret = get_user_pages_unlocked((unsigned long)buf, nr_pages, pages,
+                       FOLL_WRITE);
 
        if (ret < nr_pages) {
                nr_pages = ret;

diff --git a/include/linux/mm.h b/include/linux/mm.h
index bcdea1f4e98ced8043e8ea1e99fa11ee50b9be23..abd53f2eb74ea30ca58c7324373e6ffc63643ed3 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1287,7 +1287,7 @@ long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
                               unsigned long start, unsigned long nr_pages,
                               struct page **pages, unsigned int gup_flags);
 long get_user_pages_unlocked(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);
 

diff --git a/mm/gup.c b/mm/gup.c
index e997f545b059e473ec6e711f516931bc028fdf54..373d1ec006e4f12a17578a9405d5e191a5718f1d 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -907,17 +907,10 @@ EXPORT_SYMBOL(__get_user_pages_unlocked);
  * "force" parameter).
  */
 long get_user_pages_unlocked(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(current, current->mm, start, nr_pages,
-                                        pages, flags);
+                                        pages, gup_flags | FOLL_TOUCH);
 }
 EXPORT_SYMBOL(get_user_pages_unlocked);
 
@@ -1535,7 +1528,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
                start += nr << PAGE_SHIFT;
                pages += nr;
 
-               ret = get_user_pages_unlocked(start, nr_pages - nr, write, 0, pages);
+               ret = get_user_pages_unlocked(start, nr_pages - nr, pages,
+                               write ? FOLL_WRITE : 0);
 
                /* Have to be a bit careful with return values */
                if (nr > 0) {

diff --git a/mm/nommu.c b/mm/nommu.c
index 925dcc1fa2f3e3fa1ed0592eb806f250bbc5cb99..7e27add39f7ef764f5d921f8e50fb3b14513ac27 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -197,17 +197,10 @@ long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
 EXPORT_SYMBOL(__get_user_pages_unlocked);
 
 long get_user_pages_unlocked(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(current, current->mm, start, nr_pages,
-                                        pages, flags);
+                                        pages, gup_flags);
 }
 EXPORT_SYMBOL(get_user_pages_unlocked);
 

diff --git a/mm/util.c b/mm/util.c
index 662cddf914af2048ab6c9c674f59d37a7aceba69..4c685bde5ebc00887c25a1c008f880c10fc471e3 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -283,7 +283,8 @@ EXPORT_SYMBOL_GPL(__get_user_pages_fast);
 int __weak get_user_pages_fast(unsigned long start,
                                int nr_pages, int write, struct page **pages)
 {
-       return get_user_pages_unlocked(start, nr_pages, write, 0, pages);
+       return get_user_pages_unlocked(start, nr_pages, pages,
+                                      write ? FOLL_WRITE : 0);
 }
 EXPORT_SYMBOL_GPL(get_user_pages_fast);
 

diff --git a/net/ceph/pagevec.c b/net/ceph/pagevec.c
index 00d2601407c5dfd5b8e8a94bf5de2160ae29cc38..1a7c9a79a53c22e8e61e3b6e8e1720db71d9f9a9 100644 (file)
--- a/net/ceph/pagevec.c
+++ b/net/ceph/pagevec.c
@@ -26,7 +26,7 @@ struct page **ceph_get_direct_page_vector(const void __user *data,
        while (got < num_pages) {
                rc = get_user_pages_unlocked(
                    (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);