... we have to kmap()/kunmap(), otherwise this won't work as expected with highmem.
Fixes: c77369b437f9 ("mm/gup_test: start/stop/read functionality for PIN LONGTERM test") Signed-off-by: David Hildenbrand david@redhat.com --- mm/gup_test.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/gup_test.c b/mm/gup_test.c index 0d76d9b4bb5a..33f431e0da60 100644 --- a/mm/gup_test.c +++ b/mm/gup_test.c @@ -4,6 +4,7 @@ #include <linux/uaccess.h> #include <linux/ktime.h> #include <linux/debugfs.h> +#include <linux/highmem.h> #include "gup_test.h"
static void put_back_pages(unsigned int cmd, struct page **pages, @@ -297,10 +298,13 @@ static inline int pin_longterm_test_read(unsigned long arg) return -EFAULT;
for (i = 0; i < pin_longterm_test_nr_pages; i++) { - void *addr = page_to_virt(pin_longterm_test_pages[i]); + void *addr = kmap_local_page(pin_longterm_test_pages[i]); + unsigned long ret;
- if (copy_to_user((void __user *)(unsigned long)user_addr, addr, - PAGE_SIZE)) + ret = copy_to_user((void __user *)(unsigned long)user_addr, addr, + PAGE_SIZE); + kunmap_local(addr); + if (ret) return -EFAULT; user_addr += PAGE_SIZE; }