From patchwork Wed Jul 19 15:00:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 704404 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 462F0C0729B for ; Wed, 19 Jul 2023 15:00:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231485AbjGSPAb (ORCPT ); Wed, 19 Jul 2023 11:00:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231403AbjGSPA1 (ORCPT ); Wed, 19 Jul 2023 11:00:27 -0400 Received: from albert.telenet-ops.be (albert.telenet-ops.be [IPv6:2a02:1800:110:4::f00:1a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD66D1733 for ; Wed, 19 Jul 2023 08:00:20 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed40:51f7:4083:c317:cdf]) by albert.telenet-ops.be with bizsmtp id P30G2A00E2xuRWb0630Grg; Wed, 19 Jul 2023 17:00:16 +0200 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtp (Exim 4.95) (envelope-from ) id 1qM8es-001tPF-8Z; Wed, 19 Jul 2023 17:00:16 +0200 Received: from geert by rox.of.borg with local (Exim 4.95) (envelope-from ) id 1qM8f2-001Ass-97; Wed, 19 Jul 2023 17:00:16 +0200 From: Geert Uytterhoeven To: Rob Herring , Frank Rowand , Pantelis Antoniou Cc: devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH 01/13] of: dynamic: Do not use "%pOF" while holding devtree_lock Date: Wed, 19 Jul 2023 17:00:01 +0200 Message-Id: <416d1ea056bb2d7ec6f21d8919b96a3d48099344.1689776064.git.geert+renesas@glider.be> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Formatting strings using "%pOF" while holding devtree_lock causes a deadlock. Lockdep reports: of_get_parent from of_fwnode_get_parent+0x18/0x24 ^^^^^^^^^^^^^ of_fwnode_get_parent from fwnode_count_parents+0xc/0x28 fwnode_count_parents from fwnode_full_name_string+0x18/0xac fwnode_full_name_string from device_node_string+0x1a0/0x404 device_node_string from pointer+0x3c0/0x534 pointer from vsnprintf+0x248/0x36c vsnprintf from vprintk_store+0x130/0x3b4 Fix this by making the locking cover only the parts that really need it. Fixes: 0d638a07d3a1e98a ("of: Convert to using %pOF instead of full_name") Signed-off-by: Geert Uytterhoeven --- drivers/of/dynamic.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index e311d406b1705306..eae45a1c673ee05f 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -601,13 +601,16 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) __of_changeset_entry_dump(ce); - raw_spin_lock_irqsave(&devtree_lock, flags); switch (ce->action) { case OF_RECONFIG_ATTACH_NODE: + raw_spin_lock_irqsave(&devtree_lock, flags); __of_attach_node(ce->np); + raw_spin_unlock_irqrestore(&devtree_lock, flags); break; case OF_RECONFIG_DETACH_NODE: + raw_spin_lock_irqsave(&devtree_lock, flags); __of_detach_node(ce->np); + raw_spin_unlock_irqrestore(&devtree_lock, flags); break; case OF_RECONFIG_ADD_PROPERTY: /* If the property is in deadprops then it must be removed */ @@ -619,7 +622,9 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) } } + raw_spin_lock_irqsave(&devtree_lock, flags); ret = __of_add_property(ce->np, ce->prop); + raw_spin_unlock_irqrestore(&devtree_lock, flags); if (ret) { pr_err("changeset: add_property failed @%pOF/%s\n", ce->np, @@ -628,7 +633,9 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) } break; case OF_RECONFIG_REMOVE_PROPERTY: + raw_spin_lock_irqsave(&devtree_lock, flags); ret = __of_remove_property(ce->np, ce->prop); + raw_spin_unlock_irqrestore(&devtree_lock, flags); if (ret) { pr_err("changeset: remove_property failed @%pOF/%s\n", ce->np, @@ -647,7 +654,9 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) } } + raw_spin_lock_irqsave(&devtree_lock, flags); ret = __of_update_property(ce->np, ce->prop, &old_prop); + raw_spin_unlock_irqrestore(&devtree_lock, flags); if (ret) { pr_err("changeset: update_property failed @%pOF/%s\n", ce->np, @@ -658,7 +667,6 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) default: ret = -EINVAL; } - raw_spin_unlock_irqrestore(&devtree_lock, flags); if (ret) return ret;