From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Fri, 12 Dec 2014 15:04:16 -0800 Subject: [PATCH] clk: Really fix deadlock with mmap_sem Message-ID: <1418425456-19364-1-git-send-email-sboyd@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Commit 6314b6796e3c (clk: Don't hold prepare_lock across debugfs creation, 2014-09-04) forgot to update one place where we hold the prepare_lock while creating debugfs directories. This means we still have the chance of a deadlock that the commit was trying to fix. Actually fix it by moving the debugfs creation outside the prepare_lock. Reported-by: Russell King - ARM Linux Fixes: 6314b6796e3c "clk: Don't hold prepare_lock across debugfs creation" Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 44cdc47a6cc5..c9430653ddc9 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -240,12 +240,13 @@ static const struct file_operations clk_dump_fops = { .release = single_release, }; -/* caller must hold prepare_lock */ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) { struct dentry *d; int ret = -ENOMEM; + lockdep_assert_held(clk_debug_lock); + if (!clk || !pdentry) { ret = -EINVAL; goto out; @@ -1944,7 +1945,6 @@ int __clk_init(struct device *dev, struct clk *clk) else clk->rate = 0; - clk_debug_register(clk); /* * walk the list of orphan clocks and reparent any that are children of * this clock @@ -1979,6 +1979,9 @@ int __clk_init(struct device *dev, struct clk *clk) out: clk_prepare_unlock(); + if (!ret) + clk_debug_register(clk); + return ret; } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project