From 57480484f9f7631738ef28b952eca3c9081c4291 Mon Sep 17 00:00:00 2001 From: "Jon Medhurst (Tixy)" Date: Tue, 26 Jan 2016 17:59:13 +0000 Subject: [PATCH] component: Detach components when deleting master struct component_master_add_with_match calls find_components which, if any components already exist, it attaches to the master struct. However, if we later encounter an error the master struct is deleted, leaving components with a dangling pointer to it. If the error was a temporary one, e.g. for probe deferral, then when the master device is re-probed, it will fail to find the required components as they appear to already be attached to a master. Fix this by nulling components pointers to the master struct when it is deleted. This code is factored out into a separate function so it can be shared with component_master_del. Signed-off-by: Jon Medhurst Signed-off-by: Russell King --- drivers/base/component.c | 41 +++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 19 deletions(-) diff --git a/drivers/base/component.c b/drivers/base/component.c index 05cd26c02449..2738039aae9e 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -285,6 +285,24 @@ void component_match_add_release(struct device *master, } EXPORT_SYMBOL(component_match_add_release); +static void free_master(struct master *master) +{ + struct component_match *match = master->match; + int i; + + list_del(&master->node); + + if (match) { + for (i = 0; i < match->num; i++) { + struct component *c = match->compare[i].component; + if (c) + c->master = NULL; + } + } + + kfree(master); +} + int component_master_add_with_match(struct device *dev, const struct component_master_ops *ops, struct component_match *match) @@ -311,11 +329,9 @@ int component_master_add_with_match(struct device *dev, ret = try_to_bring_up_master(master, NULL); - if (ret < 0) { - /* Delete off the list if we weren't successful */ - list_del(&master->node); - kfree(master); - } + if (ret < 0) + free_master(master); + mutex_unlock(&component_mutex); return ret < 0 ? ret : 0; @@ -326,25 +342,12 @@ void component_master_del(struct device *dev, const struct component_master_ops *ops) { struct master *master; - int i; mutex_lock(&component_mutex); master = __master_find(dev, ops); if (master) { - struct component_match *match = master->match; - take_down_master(master); - - list_del(&master->node); - - if (match) { - for (i = 0; i < match->num; i++) { - struct component *c = match->compare[i].component; - if (c) - c->master = NULL; - } - } - kfree(master); + free_master(master); } mutex_unlock(&component_mutex); } -- 2.34.1