Following the pattern of io_uring, perf, skb, and bpf iommfd will use
user->locked_vm for accounting pinned pages. Ensure the value is included
in the struct and export free_uid() as iommufd is modular.
user->locked_vm is the correct accounting to use for ulimit because it is
per-user, and the ulimit is not supposed to be per-process. Other
places (vfio, vdpa and infiniband) have used mm->pinned_vm and/or
mm->locked_vm for accounting pinned pages, but this is only per-process
and inconsistent with the majority of the kernel.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
include/linux/sched/user.h | 2 +-
kernel/user.c | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/sched/user.h b/include/linux/sched/user.h
index 00ed419dd46413..c47dae71dad3c8 100644
--- a/include/linux/sched/user.h
+++ b/include/linux/sched/user.h
@@ -24,7 +24,7 @@ struct user_struct {
kuid_t uid;
#if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \
- defined(CONFIG_NET) || defined(CONFIG_IO_URING)
+ defined(CONFIG_NET) || defined(CONFIG_IO_URING) || IS_ENABLED(CONFIG_IOMMUFD)
atomic_long_t locked_vm;
#endif
#ifdef CONFIG_WATCH_QUEUE
diff --git a/kernel/user.c b/kernel/user.c
index e2cf8c22b539a7..d667debeafd609 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -185,6 +185,7 @@ void free_uid(struct user_struct *up)
if (refcount_dec_and_lock_irqsave(&up->__count, &uidhash_lock, &flags))
free_user(up, flags);
}
+EXPORT_SYMBOL_GPL(free_uid);
struct user_struct *alloc_uid(kuid_t uid)
{
--
2.35.1
