Commit 47872953 authored by Josef Bacik's avatar Josef Bacik Committed by Andrew Morton
Browse files

mm: cleanup flags usage in faultin_page 

Patch series "mm: some small page fault cleanups".

I was recently wreaking havoc in the page fault code and I noticed some
things that could be cleaned up.  We no longer modify the gup flags in
faultin_page, so we can clean up how we pass the flags in and remove the
extra variable in __get_user_pages.


This patch (of 2):

We're passing a pointer to the foll_flags for faultin_page, however we
never modify the flags in this call.  Change this to just take the flags
value instead.

Link: https://lkml.kernel.org/r/2df51a54c06bdf93e1cb09a19a9ef1df6557b59e.1721337845.git.josef@toxicpanda.com


Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c3954273

mm/gup.c

+10 −10
Original line number Diff line number Diff line
@@ -1153,19 +1153,19 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address, 
 * to 0 and -EBUSY returned.

 */

static int faultin_page(struct vm_area_struct *vma,

		unsigned long address, unsigned int *flags, bool unshare,

		unsigned long address, unsigned int flags, bool unshare,

		int *locked)

{

	unsigned int fault_flags = 0;

	vm_fault_t ret;



	if (*flags & FOLL_NOFAULT)

	if (flags & FOLL_NOFAULT)

		return -EFAULT;

	if (*flags & FOLL_WRITE)

	if (flags & FOLL_WRITE)

		fault_flags |= FAULT_FLAG_WRITE;

	if (*flags & FOLL_REMOTE)

	if (flags & FOLL_REMOTE)

		fault_flags |= FAULT_FLAG_REMOTE;

	if (*flags & FOLL_UNLOCKABLE) {

	if (flags & FOLL_UNLOCKABLE) {

		fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;

		/*

		 * FAULT_FLAG_INTERRUPTIBLE is opt-in. GUP callers must set
@@ -1173,12 +1173,12 @@ static int faultin_page(struct vm_area_struct *vma, 
		 * That's because some callers may not be prepared to

		 * handle early exits caused by non-fatal signals.

		 */

		if (*flags & FOLL_INTERRUPTIBLE)

		if (flags & FOLL_INTERRUPTIBLE)

			fault_flags |= FAULT_FLAG_INTERRUPTIBLE;

	}

	if (*flags & FOLL_NOWAIT)

	if (flags & FOLL_NOWAIT)

		fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT;

	if (*flags & FOLL_TRIED) {

	if (flags & FOLL_TRIED) {

		/*

		 * Note: FAULT_FLAG_ALLOW_RETRY and FAULT_FLAG_TRIED

		 * can co-exist
@@ -1212,7 +1212,7 @@ static int faultin_page(struct vm_area_struct *vma, 
	}



	if (ret & VM_FAULT_ERROR) {

		int err = vm_fault_to_errno(ret, *flags);

		int err = vm_fault_to_errno(ret, flags);



		if (err)

			return err;
@@ -1490,7 +1490,7 @@ static long __get_user_pages(struct mm_struct *mm, 


		page = follow_page_mask(vma, start, foll_flags, &ctx);

		if (!page || PTR_ERR(page) == -EMLINK) {

			ret = faultin_page(vma, start, &foll_flags,

			ret = faultin_page(vma, start, foll_flags,

					   PTR_ERR(page) == -EMLINK, locked);

			switch (ret) {

			case 0: