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authorPavel Begunkov <asml.silence@gmail.com>2022-07-12 21:52:42 +0100
committerJens Axboe <axboe@kernel.dk>2022-07-24 18:41:07 -0600
commitbc24d6bd32df0be19df3d30e74be4ba56493c0e2 (patch)
tree5eb3dd69a67f4eb5f256ec5e9253c16ab72c462b /io_uring
parent68ef5578efc8893489400b1ec30af66dab4f75ff (diff)
io_uring: add notification slot registration
Let the userspace to register and unregister notification slots. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/a0aa8161fe3ebb2a4cc6e5dbd0cffb96e6881cf5.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
-rw-r--r--io_uring/io_uring.c9
-rw-r--r--io_uring/notif.c43
-rw-r--r--io_uring/notif.h3
3 files changed, 55 insertions, 0 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 20e65d45ca1c..cae11374456e 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3870,6 +3870,15 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
break;
ret = io_register_file_alloc_range(ctx, arg);
break;
+ case IORING_REGISTER_NOTIFIERS:
+ ret = io_notif_register(ctx, arg, nr_args);
+ break;
+ case IORING_UNREGISTER_NOTIFIERS:
+ ret = -EINVAL;
+ if (arg || nr_args)
+ break;
+ ret = io_notif_unregister(ctx);
+ break;
default:
ret = -EINVAL;
break;
diff --git a/io_uring/notif.c b/io_uring/notif.c
index 0a2e98bd74f6..e6d98dc208c7 100644
--- a/io_uring/notif.c
+++ b/io_uring/notif.c
@@ -162,5 +162,48 @@ __cold int io_notif_unregister(struct io_ring_ctx *ctx)
kvfree(ctx->notif_slots);
ctx->notif_slots = NULL;
ctx->nr_notif_slots = 0;
+ io_notif_cache_purge(ctx);
+ return 0;
+}
+
+__cold int io_notif_register(struct io_ring_ctx *ctx,
+ void __user *arg, unsigned int size)
+ __must_hold(&ctx->uring_lock)
+{
+ struct io_uring_notification_slot __user *slots;
+ struct io_uring_notification_slot slot;
+ struct io_uring_notification_register reg;
+ unsigned i;
+
+ if (ctx->nr_notif_slots)
+ return -EBUSY;
+ if (size != sizeof(reg))
+ return -EINVAL;
+ if (copy_from_user(&reg, arg, sizeof(reg)))
+ return -EFAULT;
+ if (!reg.nr_slots || reg.nr_slots > IORING_MAX_NOTIF_SLOTS)
+ return -EINVAL;
+ if (reg.resv || reg.resv2 || reg.resv3)
+ return -EINVAL;
+
+ slots = u64_to_user_ptr(reg.data);
+ ctx->notif_slots = kvcalloc(reg.nr_slots, sizeof(ctx->notif_slots[0]),
+ GFP_KERNEL_ACCOUNT);
+ if (!ctx->notif_slots)
+ return -ENOMEM;
+
+ for (i = 0; i < reg.nr_slots; i++, ctx->nr_notif_slots++) {
+ struct io_notif_slot *notif_slot = &ctx->notif_slots[i];
+
+ if (copy_from_user(&slot, &slots[i], sizeof(slot))) {
+ io_notif_unregister(ctx);
+ return -EFAULT;
+ }
+ if (slot.resv[0] | slot.resv[1] | slot.resv[2]) {
+ io_notif_unregister(ctx);
+ return -EINVAL;
+ }
+ notif_slot->tag = slot.tag;
+ }
return 0;
}
diff --git a/io_uring/notif.h b/io_uring/notif.h
index 1dd48efb7744..00efe164bdc4 100644
--- a/io_uring/notif.h
+++ b/io_uring/notif.h
@@ -6,6 +6,7 @@
#include <linux/nospec.h>
#define IO_NOTIF_SPLICE_BATCH 32
+#define IORING_MAX_NOTIF_SLOTS (1U << 10)
struct io_notif {
struct ubuf_info uarg;
@@ -48,6 +49,8 @@ struct io_notif_slot {
u32 seq;
};
+int io_notif_register(struct io_ring_ctx *ctx,
+ void __user *arg, unsigned int size);
int io_notif_unregister(struct io_ring_ctx *ctx);
void io_notif_cache_purge(struct io_ring_ctx *ctx);