@@ -550,21 +550,16 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
return ret;
}
-SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
- void __user *, arg, unsigned int, nr_args)
+/*
+ * Given an 'fd' value, return the ctx associated with if. If 'registered' is
+ * true, then the registered index is used. Otherwise, the normal fd table.
+ * Caller must call fput() on the returned file, unless it's an ERR_PTR.
+ */
+struct file *io_uring_register_get_file(int fd, bool registered)
{
- struct io_ring_ctx *ctx;
- long ret = -EBADF;
struct file *file;
- bool use_registered_ring;
- use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING);
- opcode &= ~IORING_REGISTER_USE_REGISTERED_RING;
-
- if (opcode >= IORING_REGISTER_LAST)
- return -EINVAL;
-
- if (use_registered_ring) {
+ if (registered) {
/*
* Ring fd has been registered via IORING_REGISTER_RING_FDS, we
* need only dereference our task private array to find it.
@@ -572,27 +567,44 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
struct io_uring_task *tctx = current->io_uring;
if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX))
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
fd = array_index_nospec(fd, IO_RINGFD_REG_MAX);
file = tctx->registered_rings[fd];
- if (unlikely(!file))
- return -EBADF;
} else {
file = fget(fd);
- if (unlikely(!file))
- return -EBADF;
- ret = -EOPNOTSUPP;
- if (!io_is_uring_fops(file))
- goto out_fput;
}
+ if (unlikely(!file))
+ return ERR_PTR(-EBADF);
+ if (io_is_uring_fops(file))
+ return file;
+ fput(file);
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
+ void __user *, arg, unsigned int, nr_args)
+{
+ struct io_ring_ctx *ctx;
+ long ret = -EBADF;
+ struct file *file;
+ bool use_registered_ring;
+
+ use_registered_ring = !!(opcode & IORING_REGISTER_USE_REGISTERED_RING);
+ opcode &= ~IORING_REGISTER_USE_REGISTERED_RING;
+
+ if (opcode >= IORING_REGISTER_LAST)
+ return -EINVAL;
+
+ file = io_uring_register_get_file(fd, use_registered_ring);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
ctx = file->private_data;
mutex_lock(&ctx->uring_lock);
ret = __io_uring_register(ctx, opcode, arg, nr_args);
mutex_unlock(&ctx->uring_lock);
trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs, ret);
-out_fput:
if (!use_registered_ring)
fput(file);
return ret;
@@ -4,5 +4,6 @@
int io_eventfd_unregister(struct io_ring_ctx *ctx);
int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id);
+struct file *io_uring_register_get_file(int fd, bool registered);
#endif
Can be done in one of two ways: 1) Regular file descriptor, just fget() 2) Registered ring, index our own table for that In preparation for adding another register use of needing to get a ctx from a file descriptor, abstract out this helper and use it in the main register syscall as well. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- io_uring/register.c | 54 +++++++++++++++++++++++++++------------------ io_uring/register.h | 1 + 2 files changed, 34 insertions(+), 21 deletions(-)