--- x/security/landlock/tsync.c +++ y/security/landlock/tsync.c @@ -441,7 +441,7 @@ int landlock_restrict_sibling_threads(co atomic_set(&shared_ctx.preparation_error, 0); init_completion(&shared_ctx.all_prepared); init_completion(&shared_ctx.ready_to_commit); - atomic_set(&shared_ctx.num_unfinished, 1); + atomic_set(&shared_ctx.num_unfinished, 0); init_completion(&shared_ctx.all_finished); shared_ctx.old_cred = old_cred; shared_ctx.new_cred = new_cred; @@ -502,11 +502,8 @@ int landlock_restrict_sibling_threads(co * of for_each_thread(). We can reset it on each loop iteration because * all previous loop iterations are done with it already. * - * num_preparing is initialized to 1 so that the counter can not go to 0 - * and mark the completion as done before all task works are registered. - * We decrement it at the end of the loop body. */ - atomic_set(&shared_ctx.num_preparing, 1); + atomic_set(&shared_ctx.num_preparing, 0); reinit_completion(&shared_ctx.all_prepared); /* @@ -515,11 +512,7 @@ int landlock_restrict_sibling_threads(co */ found_more_threads = schedule_task_work(&works, &shared_ctx); - /* - * Decrement num_preparing for current, to undo that we initialized it - * to 1 a few lines above. - */ - if (atomic_dec_return(&shared_ctx.num_preparing) > 0) { + if (atomic_read(&shared_ctx.num_preparing) > 0) { if (wait_for_completion_interruptible( &shared_ctx.all_prepared)) { /* In case of interruption, we need to retry the system call. */ @@ -548,11 +541,7 @@ int landlock_restrict_sibling_threads(co */ complete_all(&shared_ctx.ready_to_commit); - /* - * Decrement num_unfinished for current, to undo that we initialized it to 1 - * at the beginning. - */ - if (atomic_dec_return(&shared_ctx.num_unfinished) > 0) + if (atomic_read(&shared_ctx.num_unfinished) > 0) wait_for_completion(&shared_ctx.all_finished); tsync_works_release(&works);