mm: unexport __get_user_pages()
This patch unexports the low-level __get_user_pages() function.
Recent refactoring of the get_user_pages* functions allow flags to be
passed through get_user_pages() which eliminates the need for access to
this function from its one user, kvm.
We can see that the two calls to get_user_pages() which replace
__get_user_pages() in kvm_main.c are equivalent by examining their call
stacks:
get_user_page_nowait():
get_user_pages(start, 1, flags, page, NULL)
__get_user_pages_locked(current, current->mm, start, 1, page, NULL, NULL,
false, flags | FOLL_TOUCH)
__get_user_pages(current, current->mm, start, 1,
flags | FOLL_TOUCH | FOLL_GET, page, NULL, NULL)
check_user_page_hwpoison():
get_user_pages(addr, 1, flags, NULL, NULL)
__get_user_pages_locked(current, current->mm, addr, 1, NULL, NULL, NULL,
false, flags | FOLL_TOUCH)
__get_user_pages(current, current->mm, addr, 1, flags | FOLL_TOUCH, NULL,
NULL, NULL)
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3a19185..a92c8d7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1271,10 +1271,6 @@
extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
void *buf, int len, unsigned int gup_flags);
-long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, unsigned long nr_pages,
- unsigned int foll_flags, struct page **pages,
- struct vm_area_struct **vmas, int *nonblocking);
long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
diff --git a/mm/gup.c b/mm/gup.c
index 7aa113c..ec4f827 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -526,7 +526,7 @@
* instead of __get_user_pages. __get_user_pages should be used only if
* you need some special @gup_flags.
*/
-long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
struct vm_area_struct **vmas, int *nonblocking)
@@ -631,7 +631,6 @@
} while (nr_pages);
return i;
}
-EXPORT_SYMBOL(__get_user_pages);
bool vma_permits_fault(struct vm_area_struct *vma, unsigned int fault_flags)
{
diff --git a/mm/nommu.c b/mm/nommu.c
index db5fd17..8b8faaf 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -109,7 +109,7 @@
return PAGE_SIZE << compound_order(page);
}
-long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
unsigned int foll_flags, struct page **pages,
struct vm_area_struct **vmas, int *nonblocking)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 28510e7..2907b7b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1346,21 +1346,19 @@
static int get_user_page_nowait(unsigned long start, int write,
struct page **page)
{
- int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
+ int flags = FOLL_NOWAIT | FOLL_HWPOISON;
if (write)
flags |= FOLL_WRITE;
- return __get_user_pages(current, current->mm, start, 1, flags, page,
- NULL, NULL);
+ return get_user_pages(start, 1, flags, page, NULL);
}
static inline int check_user_page_hwpoison(unsigned long addr)
{
- int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
+ int rc, flags = FOLL_HWPOISON | FOLL_WRITE;
- rc = __get_user_pages(current, current->mm, addr, 1,
- flags, NULL, NULL, NULL);
+ rc = get_user_pages(addr, 1, flags, NULL, NULL);
return rc == -EHWPOISON;
}