Skip to content
Draft
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 11 additions & 0 deletions tests/containers/io-uring/Containerfile
Original file line number Diff line number Diff line change
@@ -0,0 +1,11 @@
FROM quay.io/centos/centos:stream9 AS builder

RUN dnf install -y --enablerepo=crb gcc glibc-static

WORKDIR /build
COPY io_uring_write_raw.c .
RUN cc -static -o io_uring_write_raw io_uring_write_raw.c

FROM quay.io/centos/centos:stream9-minimal

COPY --from=builder /build/io_uring_write_raw /usr/local/bin/
167 changes: 167 additions & 0 deletions tests/containers/io-uring/io_uring_write_raw.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,167 @@
/*
* Helper that uses raw io_uring syscalls to write content to a file.
* No liburing dependency — only uses io_uring_setup/io_uring_enter
* syscalls directly, so it can be statically linked.
*
* Usage: io_uring_write_raw <file> <content>
*
* Exit codes:
* 0 - success
* 1 - usage error
* 2 - io_uring not available
* 3 - I/O error
*/
#include <errno.h>
#include <fcntl.h>
#include <linux/io_uring.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <unistd.h>

struct ring {
int fd;
struct io_uring_sqe *sqes;
unsigned *sq_tail;
unsigned *sq_mask;
unsigned *sq_array;
struct io_uring_cqe *cqes;
unsigned *cq_head;
unsigned *cq_tail;
unsigned *cq_mask;
};

static int ring_init(struct ring *r, unsigned entries)
{
struct io_uring_params p;

memset(&p, 0, sizeof(p));

int fd = syscall(__NR_io_uring_setup, entries, &p);
if (fd < 0)
return -1;

size_t sq_sz = p.sq_off.array + p.sq_entries * sizeof(unsigned);
size_t cq_sz = p.cq_off.cqes +
p.cq_entries * sizeof(struct io_uring_cqe);
size_t sqe_sz = p.sq_entries * sizeof(struct io_uring_sqe);

void *sq = mmap(NULL, sq_sz, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING);
void *cq = mmap(NULL, cq_sz, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_CQ_RING);
void *sqes = mmap(NULL, sqe_sz, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQES);

if (sq == MAP_FAILED || cq == MAP_FAILED || sqes == MAP_FAILED) {
close(fd);
return -1;
}

r->fd = fd;
r->sqes = sqes;
r->sq_tail = sq + p.sq_off.tail;
r->sq_mask = sq + p.sq_off.ring_mask;
r->sq_array = sq + p.sq_off.array;
r->cqes = cq + p.cq_off.cqes;
r->cq_head = cq + p.cq_off.head;
r->cq_tail = cq + p.cq_off.tail;
r->cq_mask = cq + p.cq_off.ring_mask;

return 0;
}

static struct io_uring_sqe *get_sqe(struct ring *r)
{
unsigned tail = __atomic_load_n(r->sq_tail, __ATOMIC_RELAXED);
unsigned idx = tail & *r->sq_mask;
struct io_uring_sqe *sqe = &r->sqes[idx];

memset(sqe, 0, sizeof(*sqe));
return sqe;
}

static int submit_and_wait(struct ring *r, struct io_uring_cqe **cqe)
{
unsigned tail = __atomic_load_n(r->sq_tail, __ATOMIC_RELAXED);
unsigned idx = tail & *r->sq_mask;

r->sq_array[idx] = idx;
__atomic_store_n(r->sq_tail, tail + 1, __ATOMIC_RELEASE);

int ret = syscall(__NR_io_uring_enter, r->fd, 1, 1,
IORING_ENTER_GETEVENTS, NULL, 0);
if (ret < 0)
return -1;

unsigned head = __atomic_load_n(r->cq_head, __ATOMIC_RELAXED);

*cqe = &r->cqes[head & *r->cq_mask];
return 0;
}

static void cqe_advance(struct ring *r)
{
unsigned head = __atomic_load_n(r->cq_head, __ATOMIC_RELAXED);

__atomic_store_n(r->cq_head, head + 1, __ATOMIC_RELEASE);
}

int main(int argc, char *argv[])
{
struct ring r;
struct io_uring_sqe *sqe;
struct io_uring_cqe *cqe;

if (argc != 3) {
fprintf(stderr, "Usage: %s <file> <content>\n", argv[0]);
return 1;
}

if (ring_init(&r, 4) < 0) {
fprintf(stderr, "io_uring_setup: %s\n", strerror(errno));
return 2;
}

/* Open file via io_uring */
sqe = get_sqe(&r);
sqe->opcode = IORING_OP_OPENAT;
sqe->fd = AT_FDCWD;
sqe->addr = (unsigned long)argv[1];
sqe->open_flags = O_WRONLY | O_TRUNC;
if (submit_and_wait(&r, &cqe) < 0 || cqe->res < 0) {
fprintf(stderr, "openat: %s\n",
strerror(-(cqe ? cqe->res : errno)));
return 3;
}
int fd = cqe->res;
cqe_advance(&r);

/* Write content via io_uring */
sqe = get_sqe(&r);
sqe->opcode = IORING_OP_WRITE;
sqe->fd = fd;
sqe->addr = (unsigned long)argv[2];
sqe->len = strlen(argv[2]);
if (submit_and_wait(&r, &cqe) < 0 || cqe->res < 0) {
fprintf(stderr, "write: %s\n",
strerror(-(cqe ? cqe->res : errno)));
return 3;
}
cqe_advance(&r);

/* Close file via io_uring */
sqe = get_sqe(&r);
sqe->opcode = IORING_OP_CLOSE;
sqe->fd = fd;
if (submit_and_wait(&r, &cqe) < 0 || cqe->res < 0) {
fprintf(stderr, "close: %s\n",
strerror(-(cqe ? cqe->res : errno)));
return 3;
}
cqe_advance(&r);

close(r.fd);
return 0;
}
124 changes: 124 additions & 0 deletions tests/test_io_uring.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,124 @@
from __future__ import annotations

import os

import docker
import docker.models.containers
import docker.models.images
import pytest

from event import Event, EventType, Process
from server import EventServer


@pytest.fixture(scope='session')
def io_uring_image(docker_client: docker.DockerClient):
image, _ = docker_client.images.build(
path='containers/io-uring',
tag='io-uring:latest',
dockerfile='Containerfile',
)
return image


@pytest.fixture
def get_io_uring_container(
io_uring_image: docker.models.images.Image,
docker_client: docker.DockerClient,
monitored_dir: str,
):
container = docker_client.containers.run(
io_uring_image.tags[0],
detach=True,
tty=True,
name='io-uring',
security_opt=['seccomp=unconfined'],
volumes={
monitored_dir: {
'bind': '/data',
'mode': 'z',
},
},
)

yield container

container.stop(timeout=1)
container.remove()


def test_io_uring_write(
monitored_dir: str,
server: EventServer,
get_io_uring_container: docker.models.containers.Container,
):
"""
Verifies that io_uring write operations are tracked by fact.

Creates a file with 'hi', modifies it to 'bye' via io_uring
(open, write, and close all go through io_uring, bypassing the
normal syscall path), then verifies the content changed and that
the io_uring file open is captured via the file_open LSM hook.
"""
fut = os.path.join(monitored_dir, 'io_uring_test.txt')
process = Process.from_proc()

# Create file with initial content via normal I/O.
with open(fut, 'w') as f:
f.write('hi')

creation = Event(
process=process,
event_type=EventType.CREATION,
file=fut,
host_path=fut,
)
server.wait_events([creation])

# Modify the file using io_uring inside the container.
# Use the low-level Docker API to obtain the exec PID, which
# appears in the io_uring worker thread name (iou-wrk-<pid>).
container = get_io_uring_container
assert container.id is not None
cmd = ['io_uring_write_raw', '/data/io_uring_test.txt', 'bye']
exec_id = container.client.api.exec_create(container.id, cmd)['Id']
output = container.client.api.exec_start(exec_id)
exec_info = container.client.api.exec_inspect(exec_id)
exit_code = exec_info['ExitCode']
exec_pid = exec_info['Pid']

if exit_code == 2:
pytest.skip(f'io_uring not supported: {output.decode()}')
assert exit_code == 0, f'io_uring write failed: {output.decode()}'

# The io_uring OPENAT operation triggers the file_open LSM hook.
# io_uring offloads blocking ops to worker threads named
# iou-wrk-<pid>, where pid is the owning process PID.
io_uring_process = Process.in_container(
exe_path='/usr/local/bin/io_uring_write_raw',
args='io_uring_write_raw /data/io_uring_test.txt bye',
name=f'iou-wrk-{exec_pid}',
container_id=container.id[:12],
)
io_uring_open = Event(
process=io_uring_process,
event_type=EventType.OPEN,
file='/data/io_uring_test.txt',
host_path=fut,
)
# Create a sentinel file via normal I/O to verify event ordering.
sentinel = os.path.join(monitored_dir, 'sentinel.txt')
with open(sentinel, 'w') as f:
f.write('sentinel')

sentinel_event = Event(
process=process,
event_type=EventType.CREATION,
file=sentinel,
host_path=sentinel,
)
server.wait_events([io_uring_open, sentinel_event])

# Verify the file was actually modified by io_uring.
with open(fut) as f:
assert f.read() == 'bye'
Loading