summaryrefslogtreecommitdiff
path: root/kernel/bpf/syscall.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/bpf/syscall.c')
-rw-r--r--kernel/bpf/syscall.c29
1 files changed, 16 insertions, 13 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 92a57efc77de..12955415d376 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2793,28 +2793,31 @@ static void bpf_link_put_deferred(struct work_struct *work)
bpf_link_free(link);
}
-/* bpf_link_put can be called from atomic context, but ensures that resources
- * are freed from process context
+/* bpf_link_put might be called from atomic context. It needs to be called
+ * from sleepable context in order to acquire sleeping locks during the process.
*/
void bpf_link_put(struct bpf_link *link)
{
if (!atomic64_dec_and_test(&link->refcnt))
return;
- if (in_atomic()) {
- INIT_WORK(&link->work, bpf_link_put_deferred);
- schedule_work(&link->work);
- } else {
- bpf_link_free(link);
- }
+ INIT_WORK(&link->work, bpf_link_put_deferred);
+ schedule_work(&link->work);
}
EXPORT_SYMBOL(bpf_link_put);
+static void bpf_link_put_direct(struct bpf_link *link)
+{
+ if (!atomic64_dec_and_test(&link->refcnt))
+ return;
+ bpf_link_free(link);
+}
+
static int bpf_link_release(struct inode *inode, struct file *filp)
{
struct bpf_link *link = filp->private_data;
- bpf_link_put(link);
+ bpf_link_put_direct(link);
return 0;
}
@@ -4787,7 +4790,7 @@ out_put_progs:
if (ret)
bpf_prog_put(new_prog);
out_put_link:
- bpf_link_put(link);
+ bpf_link_put_direct(link);
return ret;
}
@@ -4810,7 +4813,7 @@ static int link_detach(union bpf_attr *attr)
else
ret = -EOPNOTSUPP;
- bpf_link_put(link);
+ bpf_link_put_direct(link);
return ret;
}
@@ -4880,7 +4883,7 @@ static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
fd = bpf_link_new_fd(link);
if (fd < 0)
- bpf_link_put(link);
+ bpf_link_put_direct(link);
return fd;
}
@@ -4957,7 +4960,7 @@ static int bpf_iter_create(union bpf_attr *attr)
return PTR_ERR(link);
err = bpf_iter_new_fd(link);
- bpf_link_put(link);
+ bpf_link_put_direct(link);
return err;
}