From patchwork Sun Jun 2 03:37:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13682662 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 608BD2BD0F; Sun, 2 Jun 2024 03:37:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717299446; cv=none; b=ZD50P8bYP328sZ9Tg4oWYhNmLbtYMgU1jR/6SEoJAAIvM+xDbWAs7w+EyXBjtJf1CWokhPi2iaviOV+M6blYauoQ7UgvID0xDcQ+NPEr4b1tWRFGB0w41/iRJfKqZ07X7JzjWzMy29xBXI8LvDLOoOy5oEOFJyMKsvkUms9eDjc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717299446; c=relaxed/simple; bh=RcRavuCzGHOOIG2b1OsJuToXe82mFmzkJ0VhaZCnWqg=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=TRDULX41v/+4AYfSFmJiHUQi2xv9EYwFprgldhVB9rzybwG0HUH5u0lvGzwDaxkCAJnFX+odAERYyYWy7FD0o2rXKp8UzrrgXA5FnWzOk54mbI6ku4yy89UyvauDZ+F/55NcFG0CRqvaOLJtMYtWTjhA5QCv2ygX0GLjD9noRcY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA666C4AF0E; Sun, 2 Jun 2024 03:37:25 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1sDc3F-000000094OQ-02Z0; Sat, 01 Jun 2024 23:38:33 -0400 Message-ID: <20240602033832.870736657@goodmis.org> User-Agent: quilt/0.68 Date: Sat, 01 Jun 2024 23:37:55 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Alexei Starovoitov , Florent Revest , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v2 11/27] ftrace: Allow subops filtering to be modified References: <20240602033744.563858532@goodmis.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Steven Rostedt (Google)" The subops filters use a "manager" ops to enable and disable its filters. The manager ops can handle more than one subops, and its filter is what controls what functions get set. Add a ftrace_hash_move_and_update_subops() function that will update the manager ops when the subops filters change. Signed-off-by: Steven Rostedt (Google) --- include/linux/ftrace.h | 3 ++ kernel/trace/ftrace.c | 96 ++++++++++++++++++++++++++++++++++++++---- 2 files changed, 90 insertions(+), 9 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 978a1d3b270a..63238a9a9270 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -227,6 +227,7 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); * ftrace_enabled. * DIRECT - Used by the direct ftrace_ops helper for direct functions * (internal ftrace only, should not be used by others) + * SUBOP - Is controlled by another op in field managed. */ enum { FTRACE_OPS_FL_ENABLED = BIT(0), @@ -247,6 +248,7 @@ enum { FTRACE_OPS_FL_TRACE_ARRAY = BIT(15), FTRACE_OPS_FL_PERMANENT = BIT(16), FTRACE_OPS_FL_DIRECT = BIT(17), + FTRACE_OPS_FL_SUBOP = BIT(18), }; #ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS @@ -336,6 +338,7 @@ struct ftrace_ops { struct list_head list; struct list_head subop_list; ftrace_ops_func_t ops_func; + struct ftrace_ops *managed; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS unsigned long direct_call; #endif diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 38fb2a634b04..e447b04c0c9c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3424,7 +3424,8 @@ int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int } else { free_ftrace_hash(save_filter_hash); free_ftrace_hash(save_notrace_hash); - subops->flags |= FTRACE_OPS_FL_ENABLED; + subops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP; + subops->managed = ops; } return ret; } @@ -3478,11 +3479,12 @@ int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int ret = ftrace_update_ops(ops, filter_hash, notrace_hash); free_ftrace_hash(filter_hash); free_ftrace_hash(notrace_hash); - if (ret < 0) + if (ret < 0) { list_del(&subops->list); - else - subops->flags |= FTRACE_OPS_FL_ENABLED; - + } else { + subops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP; + subops->managed = ops; + } return ret; } @@ -3527,6 +3529,8 @@ int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, in free_ftrace_hash(ops->func_hash->notrace_hash); ops->func_hash->filter_hash = EMPTY_HASH; ops->func_hash->notrace_hash = EMPTY_HASH; + subops->flags &= ~(FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP); + subops->managed = NULL; return 0; } @@ -3542,16 +3546,65 @@ int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, in } ret = ftrace_update_ops(ops, filter_hash, notrace_hash); - if (ret < 0) + if (ret < 0) { list_add(&subops->list, &ops->subop_list); - else - subops->flags &= ~FTRACE_OPS_FL_ENABLED; - + } else { + subops->flags &= ~(FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_SUBOP); + subops->managed = NULL; + } free_ftrace_hash(filter_hash); free_ftrace_hash(notrace_hash); return ret; } +static int ftrace_hash_move_and_update_subops(struct ftrace_ops *subops, + struct ftrace_hash **orig_subhash, + struct ftrace_hash *hash, + int enable) +{ + struct ftrace_ops *ops = subops->managed; + struct ftrace_hash **orig_hash; + struct ftrace_hash *save_hash; + struct ftrace_hash *new_hash; + int ret; + + /* Manager ops can not be subops (yet) */ + if (WARN_ON_ONCE(!ops || ops->flags & FTRACE_OPS_FL_SUBOP)) + return -EINVAL; + + /* Move the new hash over to the subops hash */ + save_hash = *orig_subhash; + *orig_subhash = __ftrace_hash_move(hash); + if (!*orig_subhash) { + *orig_subhash = save_hash; + return -ENOMEM; + } + + /* Create a new_hash to hold the ops new functions */ + if (enable) { + orig_hash = &ops->func_hash->filter_hash; + new_hash = append_hashes(ops); + } else { + orig_hash = &ops->func_hash->notrace_hash; + new_hash = intersect_hashes(ops); + } + + /* Move the hash over to the new hash */ + ret = ftrace_hash_move_and_update_ops(ops, orig_hash, new_hash, enable); + + free_ftrace_hash(new_hash); + + if (ret) { + /* Put back the original hash */ + free_ftrace_hash_rcu(*orig_subhash); + *orig_subhash = save_hash; + } else { + free_ftrace_hash_rcu(save_hash); + } + return ret; +} + + static u64 ftrace_update_time; unsigned long ftrace_update_tot_cnt; unsigned long ftrace_number_of_pages; @@ -4770,8 +4823,33 @@ static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, { struct ftrace_ops_hash old_hash_ops; struct ftrace_hash *old_hash; + struct ftrace_ops *op; int ret; + if (ops->flags & FTRACE_OPS_FL_SUBOP) + return ftrace_hash_move_and_update_subops(ops, orig_hash, hash, enable); + + /* + * If this ops is not enabled, it could be sharing its filters + * with a subop. If that's the case, update the subop instead of + * this ops. Shared filters are only allowed to have one ops set + * at a time, and if we update the ops that is not enabled, + * it will not affect subops that share it. + */ + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) { + /* Check if any other manager subops maps to this hash */ + do_for_each_ftrace_op(op, ftrace_ops_list) { + struct ftrace_ops *subops; + + list_for_each_entry(subops, &op->subop_list, list) { + if ((subops->flags & FTRACE_OPS_FL_ENABLED) && + subops->func_hash == ops->func_hash) { + return ftrace_hash_move_and_update_subops(subops, orig_hash, hash, enable); + } + } + } while_for_each_ftrace_op(op); + } + old_hash = *orig_hash; old_hash_ops.filter_hash = ops->func_hash->filter_hash; old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;