Merge branch 'gup_flag-cleanups'

Merge the gup_flags cleanups from Lorenzo Stoakes:
 "This patch series adjusts functions in the get_user_pages* family such
  that desired FOLL_* flags are passed as an argument rather than
  implied by flags.

  The purpose of this change is to make the use of FOLL_FORCE explicit
  so it is easier to grep for and clearer to callers that this flag is
  being used.  The use of FOLL_FORCE is an issue as it overrides missing
  VM_READ/VM_WRITE flags for the VMA whose pages we are reading
  from/writing to, which can result in surprising behaviour.

  The patch series came out of the discussion around commit 38e088546522
  ("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"),
  which addressed a BUG_ON() being triggered when a page was faulted in
  with PROT_NONE set but having been overridden by FOLL_FORCE.
  do_numa_page() was run on the assumption the page _must_ be one marked
  for NUMA node migration as an actual PROT_NONE page would have been
  dealt with prior to this code path, however FOLL_FORCE introduced a
  situation where this assumption did not hold.

  See

      https://marc.info/?l=linux-mm&m=147585445805166

  for the patch proposal"

Additionally, there's a fix for an ancient bug related to FOLL_FORCE and
FOLL_WRITE by me.

[ This branch was rebased recently to add a few more acked-by's and
  reviewed-by's ]

* gup_flag-cleanups:
  mm: replace access_process_vm() write parameter with gup_flags
  mm: replace access_remote_vm() write parameter with gup_flags
  mm: replace __access_remote_vm() write parameter with gup_flags
  mm: replace get_user_pages_remote() write/force parameters with gup_flags
  mm: replace get_user_pages() write/force parameters with gup_flags
  mm: replace get_vaddr_frames() write/force parameters with gup_flags
  mm: replace get_user_pages_locked() write/force parameters with gup_flags
  mm: replace get_user_pages_unlocked() write/force parameters with gup_flags
  mm: remove write/force parameters from __get_user_pages_unlocked()
  mm: remove write/force parameters from __get_user_pages_locked()
  mm: remove gup_flags FOLL_WRITE games from __get_user_pages()

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/score/kernel/ptrace.c b/arch/score/kernel/ptrace.c
index 55836188b217..4f7314d5f334 100644
--- a/arch/score/kernel/ptrace.c
+++ b/arch/score/kernel/ptrace.c
@@ -131,7 +131,7 @@ read_tsk_long(struct task_struct *child,
 {
 	int copied;
 
-	copied = access_process_vm(child, addr, res, sizeof(*res), 0);
+	copied = access_process_vm(child, addr, res, sizeof(*res), FOLL_FORCE);
 
 	return copied != sizeof(*res) ? -EIO : 0;
 }
@@ -142,7 +142,7 @@ read_tsk_short(struct task_struct *child,
 {
 	int copied;
 
-	copied = access_process_vm(child, addr, res, sizeof(*res), 0);
+	copied = access_process_vm(child, addr, res, sizeof(*res), FOLL_FORCE);
 
 	return copied != sizeof(*res) ? -EIO : 0;
 }
@@ -153,7 +153,8 @@ write_tsk_short(struct task_struct *child,
 {
 	int copied;
 
-	copied = access_process_vm(child, addr, &val, sizeof(val), 1);
+	copied = access_process_vm(child, addr, &val, sizeof(val),
+			FOLL_FORCE | FOLL_WRITE);
 
 	return copied != sizeof(val) ? -EIO : 0;
 }
@@ -164,7 +165,8 @@ write_tsk_long(struct task_struct *child,
 {
 	int copied;
 
-	copied = access_process_vm(child, addr, &val, sizeof(val), 1);
+	copied = access_process_vm(child, addr, &val, sizeof(val),
+			FOLL_FORCE | FOLL_WRITE);
 
 	return copied != sizeof(val) ? -EIO : 0;
 }