From 8b7457ef9a9eb46cd1675d40d8e1fd3c47a38395 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Wed, 14 Dec 2016 15:06:55 -0800 Subject: mm: unexport __get_user_pages_unlocked() Unexport the low-level __get_user_pages_unlocked() function and replaces invocations with calls to more appropriate higher-level functions. In hva_to_pfn_slow() we are able to replace __get_user_pages_unlocked() with get_user_pages_unlocked() since we can now pass gup_flags. In async_pf_execute() and process_vm_rw_single_vec() we need to pass different tsk, mm arguments so get_user_pages_remote() is the sane replacement in these cases (having added manual acquisition and release of mmap_sem.) Additionally get_user_pages_remote() reintroduces use of the FOLL_TOUCH flag. However, this flag was originally silently dropped by commit 1e9877902dc7 ("mm/gup: Introduce get_user_pages_remote()"), so this appears to have been unintentional and reintroducing it is therefore not an issue. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20161027095141.2569-3-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes Acked-by: Michal Hocko Cc: Jan Kara Cc: Hugh Dickins Cc: Dave Hansen Cc: Rik van Riel Cc: Mel Gorman Cc: Paolo Bonzini Cc: Radim Krcmar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/process_vm_access.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'mm/process_vm_access.c') diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index be8dc8d1edb9..84d0c7eada2b 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -88,7 +88,7 @@ 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 = FOLL_REMOTE; + unsigned int flags = 0; /* Work out address and page range required */ if (len == 0) @@ -100,15 +100,19 @@ static int process_vm_rw_single_vec(unsigned long addr, while (!rc && nr_pages && iov_iter_count(iter)) { int pages = min(nr_pages, max_pages_per_loop); + int locked = 1; size_t bytes; /* * Get the pages we're interested in. We must - * add FOLL_REMOTE because task/mm might not + * access remotely because task/mm might not * current/current->mm */ - pages = __get_user_pages_unlocked(task, mm, pa, pages, - process_pages, flags); + down_read(&mm->mmap_sem); + pages = get_user_pages_remote(task, mm, pa, pages, flags, + process_pages, NULL, &locked); + if (locked) + up_read(&mm->mmap_sem); if (pages <= 0) return -EFAULT; -- cgit v1.2.3