diff options
| author | Stanislav Fomichev <sdf@google.com> | 2019-05-29 00:14:42 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-05-29 16:17:35 +0300 |
| commit | 02205d2ed6fe26a8f4fd9e9cec251d1dc7f79316 (patch) | |
| tree | ed0f1928b18a5950007b1c9ff27c3e79c778da81 /drivers/media/rc | |
| parent | 54e9c9d4b506b611228890752d1cfa960e0965e1 (diff) | |
| download | linux-02205d2ed6fe26a8f4fd9e9cec251d1dc7f79316.tar.xz | |
bpf: media: properly use bpf_prog_array api
Now that we don't have __rcu markers on the bpf_prog_array helpers,
let's use proper rcu_dereference_protected to obtain array pointer
under mutex.
Cc: linux-media@vger.kernel.org
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Sean Young <sean@mess.org>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'drivers/media/rc')
| -rw-r--r-- | drivers/media/rc/bpf-lirc.c | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c index ee657003c1a1..0a0ce620e4a2 100644 --- a/drivers/media/rc/bpf-lirc.c +++ b/drivers/media/rc/bpf-lirc.c @@ -8,6 +8,9 @@ #include <linux/bpf_lirc.h> #include "rc-core-priv.h" +#define lirc_rcu_dereference(p) \ + rcu_dereference_protected(p, lockdep_is_held(&ir_raw_handler_lock)) + /* * BPF interface for raw IR */ @@ -136,7 +139,7 @@ const struct bpf_verifier_ops lirc_mode2_verifier_ops = { static int lirc_bpf_attach(struct rc_dev *rcdev, struct bpf_prog *prog) { - struct bpf_prog_array __rcu *old_array; + struct bpf_prog_array *old_array; struct bpf_prog_array *new_array; struct ir_raw_event_ctrl *raw; int ret; @@ -154,12 +157,12 @@ static int lirc_bpf_attach(struct rc_dev *rcdev, struct bpf_prog *prog) goto unlock; } - if (raw->progs && bpf_prog_array_length(raw->progs) >= BPF_MAX_PROGS) { + old_array = lirc_rcu_dereference(raw->progs); + if (old_array && bpf_prog_array_length(old_array) >= BPF_MAX_PROGS) { ret = -E2BIG; goto unlock; } - old_array = raw->progs; ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); if (ret < 0) goto unlock; @@ -174,7 +177,7 @@ unlock: static int lirc_bpf_detach(struct rc_dev *rcdev, struct bpf_prog *prog) { - struct bpf_prog_array __rcu *old_array; + struct bpf_prog_array *old_array; struct bpf_prog_array *new_array; struct ir_raw_event_ctrl *raw; int ret; @@ -192,7 +195,7 @@ static int lirc_bpf_detach(struct rc_dev *rcdev, struct bpf_prog *prog) goto unlock; } - old_array = raw->progs; + old_array = lirc_rcu_dereference(raw->progs); ret = bpf_prog_array_copy(old_array, prog, NULL, &new_array); /* * Do not use bpf_prog_array_delete_safe() as we would end up @@ -223,21 +226,22 @@ void lirc_bpf_run(struct rc_dev *rcdev, u32 sample) /* * This should be called once the rc thread has been stopped, so there can be * no concurrent bpf execution. + * + * Should be called with the ir_raw_handler_lock held. */ void lirc_bpf_free(struct rc_dev *rcdev) { struct bpf_prog_array_item *item; + struct bpf_prog_array *array; - if (!rcdev->raw->progs) + array = lirc_rcu_dereference(rcdev->raw->progs); + if (!array) return; - item = rcu_dereference(rcdev->raw->progs)->items; - while (item->prog) { + for (item = array->items; item->prog; item++) bpf_prog_put(item->prog); - item++; - } - bpf_prog_array_free(rcdev->raw->progs); + bpf_prog_array_free(array); } int lirc_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) @@ -290,7 +294,7 @@ int lirc_prog_detach(const union bpf_attr *attr) int lirc_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) { __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); - struct bpf_prog_array __rcu *progs; + struct bpf_prog_array *progs; struct rc_dev *rcdev; u32 cnt, flags = 0; int ret; @@ -311,7 +315,7 @@ int lirc_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) if (ret) goto put; - progs = rcdev->raw->progs; + progs = lirc_rcu_dereference(rcdev->raw->progs); cnt = progs ? bpf_prog_array_length(progs) : 0; if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt))) { |