clk: validate pointer in __clk_disable()
commite47c6a3408ea6bcfc5204f23d5a5b209de6e68b9
authorFengguang Wu <fengguang.wu@intel.com>
Mon, 30 Jul 2012 21:39:54 +0000 (30 14:39 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 31 Jul 2012 00:25:13 +0000 (30 17:25 -0700)
tree0f515a18546fb2875a46d5cead87cb90e1401e38
parent7041717e7c6ca33310d0c7333d9f7cebc65b2534
clk: validate pointer in __clk_disable()

clk_get() returns -ENOENT on error and some careless caller might
dereference it without error checking:

In mxc_rnga_remove():

        struct clk *clk = clk_get(&pdev->dev, "rng");

// ...

        clk_disable(clk);

Since it's insane to audit the lots of existing and future clk users,
let's add a check in the callee to avoid kernel panic and warn about
any buggy user.

Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
Cc: viresh kumar <viresh.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/clk/clk.c