Putting the cpumask on the stack is deprecated for a long time (since
2d3854a37e8), as these can be big. Given that, change the on-stack
allocation of allowed_mask to be dynamically allocated.
Fixes: f011c9cf04c0 ("io_uring/sqpoll: do not allow pinning outside of cpuset")
Signed-off-by: Felix Moessbauer <felix.moessbauer@xxxxxxxxxxx>
---
Changes since v2:
- reworded commit message
- make error checking consisten with pattern used in kernel
@Jens: Thanks for guiding me and helping me to get this right.
Much appreciated.
Changes since v1:
- don't leak mask in case CPU is not online or too big
Best regards,
Felix
io_uring/sqpoll.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c
index 7adfcf6818ff..7c79685baeb1 100644
--- a/io_uring/sqpoll.c
+++ b/io_uring/sqpoll.c
@@ -461,15 +461,22 @@ __cold int io_sq_offload_create(struct io_ring_ctx *ctx,
return 0;
if (p->flags & IORING_SETUP_SQ_AFF) {
- struct cpumask allowed_mask;
+ cpumask_var_t allowed_mask;
int cpu = p->sq_thread_cpu;
ret = -EINVAL;
if (cpu >= nr_cpu_ids || !cpu_online(cpu))
goto err_sqpoll;
- cpuset_cpus_allowed(current, &allowed_mask);
- if (!cpumask_test_cpu(cpu, &allowed_mask))
+ ret = -ENOMEM;
+ if (!alloc_cpumask_var(&allowed_mask, GFP_KERNEL))
goto err_sqpoll;
+ ret = -EINVAL;
+ cpuset_cpus_allowed(current, allowed_mask);
+ if (!cpumask_test_cpu(cpu, allowed_mask)) {
+ free_cpumask_var(allowed_mask);
+ goto err_sqpoll;
+ }
+ free_cpumask_var(allowed_mask);
sqd->sq_cpu = cpu;
} else {
sqd->sq_cpu = -1;
--
2.39.2
