@@ -426,6 +426,7 @@ struct bpf_verifier_state {
* while they are still in use.
*/
bool used_as_loop_entry;
+ bool in_sleepable;
/* first and last insn idx of this verifier state */
u32 first_insn_idx;
@@ -1434,6 +1434,7 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
}
dst_state->speculative = src->speculative;
dst_state->active_rcu_lock = src->active_rcu_lock;
+ dst_state->in_sleepable = src->in_sleepable;
dst_state->curframe = src->curframe;
dst_state->active_lock.ptr = src->active_lock.ptr;
dst_state->active_lock.id = src->active_lock.id;
@@ -2407,7 +2408,7 @@ static void init_func_state(struct bpf_verifier_env *env,
/* Similar to push_stack(), but for async callbacks */
static struct bpf_verifier_state *push_async_cb(struct bpf_verifier_env *env,
int insn_idx, int prev_insn_idx,
- int subprog)
+ int subprog, bool is_sleepable)
{
struct bpf_verifier_stack_elem *elem;
struct bpf_func_state *frame;
@@ -2434,6 +2435,7 @@ static struct bpf_verifier_state *push_async_cb(struct bpf_verifier_env *env,
* Initialize it similar to do_check_common().
*/
elem->st.branches = 1;
+ elem->st.in_sleepable = is_sleepable;
frame = kzalloc(sizeof(*frame), GFP_KERNEL);
if (!frame)
goto err;
@@ -5279,7 +5281,8 @@ static int map_kptr_match_type(struct bpf_verifier_env *env,
static bool in_sleepable(struct bpf_verifier_env *env)
{
- return env->prog->sleepable;
+ return env->prog->sleepable ||
+ (env->cur_state && env->cur_state->in_sleepable);
}
/* The non-sleepable programs and sleepable programs with explicit bpf_rcu_read_lock()
@@ -9493,7 +9496,8 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins
/* there is no real recursion here. timer callbacks are async */
env->subprog_info[subprog].is_async_cb = true;
async_cb = push_async_cb(env, env->subprog_info[subprog].start,
- insn_idx, subprog);
+ insn_idx, subprog,
+ is_bpf_timer_set_sleepable_cb_impl_kfunc(insn->imm));
if (!async_cb)
return -EFAULT;
callee = async_cb->frame[0];
@@ -16941,6 +16945,9 @@ static bool states_equal(struct bpf_verifier_env *env,
if (old->active_rcu_lock != cur->active_rcu_lock)
return false;
+ if (old->in_sleepable != cur->in_sleepable)
+ return false;
+
/* for states to be equal callsites have to be the same
* and all frame states need to be equivalent
*/
Now that we have bpf_timer_set_sleepable_cb() available and working, we can tag the attached callback as sleepable, and let the verifier check in the correct context the calls and kfuncs. Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> --- no changes in v5 changes in v4: - use a function parameter to forward the sleepable information new in v3 (split from v2 02/10) --- include/linux/bpf_verifier.h | 1 + kernel/bpf/verifier.c | 13 ++++++++++--- 2 files changed, 11 insertions(+), 3 deletions(-)