diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-08-13 00:19:19 +0200 |
|---|---|---|
| committer | Eduard Zingerman <eddyz87@gmail.com> | 2026-08-12 17:45:07 -0700 |
| commit | 6137fb7c5f830d07909cbc789f52b1e0fffd6cd2 (patch) | |
| tree | df340d27c103c4339f033385bf57ef1343224c13 /kernel | |
| parent | 14c950ac2be8cadb63e1bfe22111ab0fdc829eb8 (diff) | |
bpf: Attribute async callback instructions to verification roots
Asynchronous callbacks are explored as fresh frame-zero verifier states,
so normal callee-to-caller accounting cannot propagate their instruction
budget to the main or global subprogram whose verification scheduled them.
The callback exploration still happens within the same do_check_common()
invocation as that independent verification root. Record
env->insn_processed at do_check_common() entry and override the root's
inclusive count with the delta before returning. This includes all directly
and transitively scheduled asynchronous callbacks in the root's total
without maintaining a separate accounting call stack.
Static subprogram and callback totals remain local to their synchronous call
paths. Their self counts continue to account for each processed instruction
exactly once.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260812221925.3358041-3-memxor@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 51d754bdef5d..fced21ec2304 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -18448,6 +18448,7 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog) struct bpf_prog_aux *aux = env->prog->aux; struct bpf_verifier_state *state; struct bpf_reg_state *regs; + u32 insn_processed = env->insn_processed; int ret, i; env->prev_linfo = NULL; @@ -18590,6 +18591,15 @@ out: if (!ret && pop_log) bpf_vlog_reset(&env->log, 0); free_states(env); + + /* + * The override is needed to account for async subprograms, which + * are verified with their own set of stack frames and thus are + * not accounted as callees by account_current_path(). + * Accumulate their total counts as total counts of the main or + * global subprog hosting the async call. + */ + env->subprog_info[subprog].insns_total = env->insn_processed - insn_processed; return ret; } |