v3: - added IORING_RESTRICTION_SQE_FLAGS_ALLOWED and IORING_RESTRICTION_SQE_FLAGS_REQUIRED - removed IORING_RESTRICTION_FIXED_FILES_ONLY opcode - enabled restrictions only when the rings start RFC v2: https://lore.kernel.org/io-uring/20200716124833.93667-1-sgarzare@xxxxxxxxxx RFC v1: https://lore.kernel.org/io-uring/20200710141945.129329-1-sgarzare@xxxxxxxxxx Following the proposal that I send about restrictions [1], I wrote this series to add restrictions in io_uring. I also wrote helpers in liburing and a test case (test/register-restrictions.c) available in this repository: https://github.com/stefano-garzarella/liburing (branch: io_uring_restrictions) Just to recap the proposal, the idea is to add some restrictions to the operations (sqe opcode and flags, register opcode) to safely allow untrusted applications or guests to use io_uring queues. The first patch changes io_uring_register(2) opcodes into an enumeration to keep track of the last opcode available. The second patch adds IOURING_REGISTER_RESTRICTIONS opcode and the code to handle restrictions. The third patch adds IORING_SETUP_R_DISABLED flag to start the rings disabled, allowing the user to register restrictions, buffers, files, before to start processing SQEs. Comments and suggestions are very welcome. Thank you in advance, Stefano [1] https://lore.kernel.org/io-uring/20200609142406.upuwpfmgqjeji4lc@steredhat/ Stefano Garzarella (3): io_uring: use an enumeration for io_uring_register(2) opcodes io_uring: add IOURING_REGISTER_RESTRICTIONS opcode io_uring: allow disabling rings during the creation fs/io_uring.c | 167 ++++++++++++++++++++++++++++++++-- include/uapi/linux/io_uring.h | 60 +++++++++--- 2 files changed, 207 insertions(+), 20 deletions(-) -- 2.26.2