From 91429023342789a89f4b6ae95b47a7df71ab6d95 Mon Sep 17 00:00:00 2001 From: John Hubbard Date: Mon, 1 Jun 2020 21:48:27 -0700 Subject: [PATCH] mm/gup: introduce pin_user_pages_unlocked Introduce pin_user_pages_unlocked(), which is nearly identical to the get_user_pages_unlocked() that it wraps, except that it sets FOLL_PIN and rejects FOLL_GET. Signed-off-by: John Hubbard Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Cc: Andy Walls Cc: Mauro Carvalho Chehab Link: http://lkml.kernel.org/r/20200518012157.1178336-2-jhubbard@nvidia.com Signed-off-by: Linus Torvalds --- include/linux/mm.h | 2 ++ mm/gup.c | 17 +++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 92704fde64757..ebbb0acbeee23 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1713,6 +1713,8 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, int *locked); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); +long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages, + struct page **pages, unsigned int gup_flags); int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages); diff --git a/mm/gup.c b/mm/gup.c index ca723a33268ea..c3014669988b8 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2960,3 +2960,20 @@ long pin_user_pages(unsigned long start, unsigned long nr_pages, pages, vmas, gup_flags); } EXPORT_SYMBOL(pin_user_pages); + +/* + * pin_user_pages_unlocked() is the FOLL_PIN variant of + * get_user_pages_unlocked(). Behavior is the same, except that this one sets + * FOLL_PIN and rejects FOLL_GET. + */ +long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages, + struct page **pages, unsigned int gup_flags) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= FOLL_PIN; + return get_user_pages_unlocked(start, nr_pages, pages, gup_flags); +} +EXPORT_SYMBOL(pin_user_pages_unlocked); -- 2.30.2