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: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 1840615..8fe601b 100644 (file)
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -681,16 +681,16 @@ 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,
-                               struct vm_area_struct **prev,
-                               unsigned long start, unsigned long end)
+void userfaultfd_remove(struct vm_area_struct *vma,
+                       struct vm_area_struct **prev,
+                       unsigned long start, unsigned long end)
 {
        struct mm_struct *mm = vma->vm_mm;
        struct userfaultfd_ctx *ctx;
        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);
 

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index f431861..2521542 100644 (file)
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -61,10 +61,10 @@ 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,
-                                      struct vm_area_struct **prev,
-                                      unsigned long start,
-                                      unsigned long end);
+extern void userfaultfd_remove(struct vm_area_struct *vma,
+                              struct vm_area_struct **prev,
+                              unsigned long start,
+                              unsigned long end);
 
 #else /* CONFIG_USERFAULTFD */
 
@@ -112,10 +112,10 @@ static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
 {
 }
 
-static inline void madvise_userfault_dontneed(struct vm_area_struct *vma,
-                                             struct vm_area_struct **prev,
-                                             unsigned long start,
-                                             unsigned long end)
+static inline void userfaultfd_remove(struct vm_area_struct *vma,
+                                     struct vm_area_struct **prev,
+                                     unsigned long start,
+                                     unsigned long end)
 {
 }
 #endif /* CONFIG_USERFAULTFD */

diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 9ac4b68..b742c40 100644 (file)
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -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;

diff --git a/mm/madvise.c b/mm/madvise.c
index b530a49..ab5ef14 100644 (file)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -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;
 }

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 5a840a6..9eb77df 100644 (file)
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -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);