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#include "../config-host.h"
/* SPDX-License-Identifier: MIT */
/*
* Description: test ring resize failure handling when mmap fails.
* Ensures the previous ring state remains valid and usable on failure.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/resource.h>
#include "liburing.h"
#include "helpers.h"
static long get_vm_size_pages(void)
{
FILE *f = fopen("/proc/self/statm", "r");
if (!f)
return -1;
long pages = 0;
if (fscanf(f, "%ld", &pages) != 1)
pages = -1;
fclose(f);
return pages;
}
int main(int argc, char *argv[])
{
struct io_uring_params p = { };
struct io_uring ring;
struct rlimit old_rlim, new_rlim;
long pages, page_size;
int ret;
if (argc > 1)
return T_EXIT_SKIP;
/* Initialize small ring */
ret = io_uring_queue_init(8, &ring, 0);
if (ret) {
fprintf(stderr, "ring setup failed: %d\n", ret);
return T_EXIT_FAIL;
}
/* Verify original ring works before any resize */
struct io_uring_sqe *sqe = io_uring_get_sqe(&ring);
if (!sqe) {
fprintf(stderr, "Failed to get sqe\n");
return T_EXIT_FAIL;
}
io_uring_prep_nop(sqe);
ret = io_uring_submit_and_wait(&ring, 1);
if (ret < 0) {
fprintf(stderr, "submit failed: %d\n", ret);
return T_EXIT_FAIL;
}
struct io_uring_cqe *cqe;
ret = io_uring_peek_cqe(&ring, &cqe);
if (ret < 0) {
fprintf(stderr, "peek cqe failed: %d\n", ret);
return T_EXIT_FAIL;
}
io_uring_cqe_seen(&ring, cqe);
/* Get virtual memory size and pagesize */
pages = get_vm_size_pages();
page_size = sysconf(_SC_PAGESIZE);
if (pages < 0 || page_size < 0) {
fprintf(stderr, "Failed to get VM size or page size\n");
return T_EXIT_SKIP;
}
/* Get old resource limit */
if (getrlimit(RLIMIT_AS, &old_rlim) < 0) {
perror("getrlimit");
return T_EXIT_FAIL;
}
/* Set tight virtual memory limit to current usage + 2 pages */
new_rlim.rlim_cur = (pages + 2) * page_size;
new_rlim.rlim_max = old_rlim.rlim_max;
if (setrlimit(RLIMIT_AS, &new_rlim) < 0) {
perror("setrlimit");
return T_EXIT_FAIL;
}
/* Attempt resize to a larger size which is guaranteed to exceed the memory limit */
memset(&p, 0, sizeof(p));
p.sq_entries = 64;
p.cq_entries = 128;
ret = io_uring_resize_rings(&ring, &p);
/* Restore old limit immediately so standard calls are safe */
setrlimit(RLIMIT_AS, &old_rlim);
/* We expect resize to fail with -ENOMEM due to our tight memory limit */
if (ret >= 0) {
fprintf(stderr, "Resize unexpectedly succeeded under memory pressure\n");
io_uring_queue_exit(&ring);
return T_EXIT_FAIL;
}
/* Ensure the old ring is STILL fully functional and did not crash */
sqe = io_uring_get_sqe(&ring);
if (!sqe) {
fprintf(stderr, "Failed to get sqe after failed resize (ring is broken)\n");
return T_EXIT_FAIL;
}
io_uring_prep_nop(sqe);
ret = io_uring_submit_and_wait(&ring, 1);
if (ret < 0) {
fprintf(stderr, "Submit failed after failed resize (ring is broken): %d\n", ret);
return T_EXIT_FAIL;
}
ret = io_uring_peek_cqe(&ring, &cqe);
if (ret < 0) {
fprintf(stderr, "Peek cqe failed after failed resize: %d\n", ret);
return T_EXIT_FAIL;
}
io_uring_cqe_seen(&ring, cqe);
io_uring_queue_exit(&ring);
return T_EXIT_PASS;
}
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