Commit d811914d authored by Mike Rapoport's avatar Mike Rapoport Committed by Linus Torvalds
Browse files

userfaultfd: non-cooperative: rename *EVENT_MADVDONTNEED to *EVENT_REMOVE 

Patch series "userfaultfd: non-cooperative: add madvise() event for
MADV_REMOVE request".

These patches add notification of madvise(MADV_REMOVE) event to
non-cooperative userfaultfd monitor.

The first pacth renames EVENT_MADVDONTNEED to EVENT_REMOVE along with
relevant functions and structures.  Using _REMOVE instead of
_MADVDONTNEED describes the event semantics more clearly and I hope it's
not too late for such change in the ABI.

This patch (of 3):

The UFFD_EVENT_MADVDONTNEED purpose is to notify uffd monitor about
removal of certain range from address space tracked by userfaultfd.
Hence, UFFD_EVENT_REMOVE seems to better reflect the operation
semantics.  Respectively, 'madv_dn' field of uffd_msg is renamed to
'remove' and the madvise_userfault_dontneed callback is renamed to
userfaultfd_remove.

Link: http://lkml.kernel.org/r/1484814154-1557-2-git-send-email-rppt@linux.vnet.ibm.com


Signed-off-by: default avatarMike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Acked-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0262d9c8

fs/userfaultfd.c

+7 −7
Original line number Diff line number Diff line
@@ -681,7 +681,7 @@ void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *vm_ctx, 
	userfaultfd_event_wait_completion(ctx, &ewq);

}



void madvise_userfault_dontneed(struct vm_area_struct *vma,

void userfaultfd_remove(struct vm_area_struct *vma,

			struct vm_area_struct **prev,

			unsigned long start, unsigned long end)

{
@@ -690,7 +690,7 @@ void madvise_userfault_dontneed(struct vm_area_struct *vma, 
	struct userfaultfd_wait_queue ewq;



	ctx = vma->vm_userfaultfd_ctx.ctx;

	if (!ctx || !(ctx->features & UFFD_FEATURE_EVENT_MADVDONTNEED))

	if (!ctx || !(ctx->features & UFFD_FEATURE_EVENT_REMOVE))

		return;



	userfaultfd_ctx_get(ctx);
@@ -700,9 +700,9 @@ void madvise_userfault_dontneed(struct vm_area_struct *vma, 


	msg_init(&ewq.msg);



	ewq.msg.event = UFFD_EVENT_MADVDONTNEED;

	ewq.msg.arg.madv_dn.start = start;

	ewq.msg.arg.madv_dn.end = end;

	ewq.msg.event = UFFD_EVENT_REMOVE;

	ewq.msg.arg.remove.start = start;

	ewq.msg.arg.remove.end = end;



	userfaultfd_event_wait_completion(ctx, &ewq);

include/linux/userfaultfd_k.h

+8 −8
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *, 
					unsigned long from, unsigned long to,

					unsigned long len);



extern void madvise_userfault_dontneed(struct vm_area_struct *vma,

extern void userfaultfd_remove(struct vm_area_struct *vma,

			       struct vm_area_struct **prev,

			       unsigned long start,

			       unsigned long end);
@@ -112,7 +112,7 @@ static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx, 
{

}



static inline void madvise_userfault_dontneed(struct vm_area_struct *vma,

static inline void userfaultfd_remove(struct vm_area_struct *vma,

				      struct vm_area_struct **prev,

				      unsigned long start,

				      unsigned long end)

include/uapi/linux/userfaultfd.h

+4 −4
Original line number Diff line number Diff line
@@ -20,7 +20,7 @@ 
#define UFFD_API ((__u64)0xAA)

#define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK |		\

			   UFFD_FEATURE_EVENT_REMAP |		\

			   UFFD_FEATURE_EVENT_MADVDONTNEED |	\

			   UFFD_FEATURE_EVENT_REMOVE |	\

			   UFFD_FEATURE_MISSING_HUGETLBFS |	\

			   UFFD_FEATURE_MISSING_SHMEM)

#define UFFD_API_IOCTLS				\
@@ -92,7 +92,7 @@ struct uffd_msg { 
		struct {

			__u64	start;

			__u64	end;

		} madv_dn;

		} remove;



		struct {

			/* unused reserved fields */
@@ -109,7 +109,7 @@ struct uffd_msg { 
#define UFFD_EVENT_PAGEFAULT	0x12

#define UFFD_EVENT_FORK		0x13

#define UFFD_EVENT_REMAP	0x14

#define UFFD_EVENT_MADVDONTNEED	0x15

#define UFFD_EVENT_REMOVE	0x15



/* flags for UFFD_EVENT_PAGEFAULT */

#define UFFD_PAGEFAULT_FLAG_WRITE	(1<<0)	/* If this was a write fault */
@@ -155,7 +155,7 @@ struct uffdio_api { 
#define UFFD_FEATURE_PAGEFAULT_FLAG_WP		(1<<0)

#define UFFD_FEATURE_EVENT_FORK			(1<<1)

#define UFFD_FEATURE_EVENT_REMAP		(1<<2)

#define UFFD_FEATURE_EVENT_MADVDONTNEED		(1<<3)

#define UFFD_FEATURE_EVENT_REMOVE		(1<<3)

#define UFFD_FEATURE_MISSING_HUGETLBFS		(1<<4)

#define UFFD_FEATURE_MISSING_SHMEM		(1<<5)

	__u64 features;

mm/madvise.c

+1 −1
Original line number Diff line number Diff line
@@ -479,7 +479,7 @@ static long madvise_dontneed(struct vm_area_struct *vma, 
	if (!can_madv_dontneed_vma(vma))

		return -EINVAL;



	madvise_userfault_dontneed(vma, prev, start, end);

	userfaultfd_remove(vma, prev, start, end);

	zap_page_range(vma, start, end - start);

	return 0;

}

tools/testing/selftests/vm/userfaultfd.c

+8 −8
Original line number Diff line number Diff line
@@ -398,12 +398,12 @@ static void *uffd_poll_thread(void *arg) 
			uffd = msg.arg.fork.ufd;

			pollfd[0].fd = uffd;

			break;

		case UFFD_EVENT_MADVDONTNEED:

			uffd_reg.range.start = msg.arg.madv_dn.start;

			uffd_reg.range.len = msg.arg.madv_dn.end -

				msg.arg.madv_dn.start;

		case UFFD_EVENT_REMOVE:

			uffd_reg.range.start = msg.arg.remove.start;

			uffd_reg.range.len = msg.arg.remove.end -

				msg.arg.remove.start;

			if (ioctl(uffd, UFFDIO_UNREGISTER, &uffd_reg.range))

				fprintf(stderr, "madv_dn failure\n"), exit(1);

				fprintf(stderr, "remove failure\n"), exit(1);

			break;

		case UFFD_EVENT_REMAP:

			area_dst = (char *)(unsigned long)msg.arg.remap.to;
@@ -570,7 +570,7 @@ static int userfaultfd_open(int features) 
 * mremap, the entire monitored area is accessed in a single pass for

 * HUGETLB_TEST.

 * The release of the pages currently generates event only for

 * anonymous memory (UFFD_EVENT_MADVDONTNEED), hence it is not checked

 * anonymous memory (UFFD_EVENT_REMOVE), hence it is not checked

 * for hugetlb and shmem.

 */

static int faulting_process(void)
@@ -715,14 +715,14 @@ static int userfaultfd_events_test(void) 
	pid_t pid;

	char c;



	printf("testing events (fork, remap, madv_dn): ");

	printf("testing events (fork, remap, remove): ");

	fflush(stdout);



	if (release_pages(area_dst))

		return 1;



	features = UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_EVENT_REMAP |

		UFFD_FEATURE_EVENT_MADVDONTNEED;

		UFFD_FEATURE_EVENT_REMOVE;

	if (userfaultfd_open(features) < 0)

		return 1;

	fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK);

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