Hi Russell,
On Tue, 3 Feb 2009, Paul Walmsley wrote:
> On Sat, 31 Jan 2009, Russell King - ARM Linux wrote:
>
> > On Tue, Jan 27, 2009 at 07:44:08PM -0700, Paul Walmsley wrote:
> > > diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
> > > index 55c5d67..7aa09f5 100644
> > > --- a/arch/arm/mach-omap2/clock.c
> > > +++ b/arch/arm/mach-omap2/clock.c
> > > @@ -77,17 +77,17 @@ void omap2_init_clk_clkdm(struct clk *clk)
...
> > This is unsafe - if the clock domain can not be found, you leave the
> > union pointing at the string, and there's no way for this to prevent
> > the clock from being registered.
>
> Agreed. Now that omap2_init_clk_clkdm() is called by the
> OMAP arch-specific clk_register(), this should be pretty easy to
> implement. Will send a patch that applies on top of F 06.
The following patch prevents a clock with a bad or missing clockdomain
from registering. It applies after F 06.
- Paul
From: Paul Walmsley <paul@xxxxxxxxx>
Date: Wed, 4 Feb 2009 15:11:20 -0700
OMAP2/3 clock: prevent clock registration with bad or missing clockdomain
If clk_register() is called on a struct clk without a clockdomain
name, or a struct clk which contains an invalid clockdomain name, fail
the clock registration. This prevents later code from inadvertently
dereferencing the clockdomain name string as a struct clockdomain
pointer.
Problem reported by Russell King <linux@xxxxxxxxxxxxxxxx>.
Tested on BeagleBoard ES2.1.
Signed-off-by: Paul Walmsley <paul@xxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>.
---
arch/arm/mach-omap2/clock.c | 21 ++++++++++-----------
1 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index 600b2f4..53069cd 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -188,26 +188,32 @@ static int _dpll_test_fint(struct clk *clk, u8 n)
}
/**
- * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
+ * _omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
* @clk: OMAP clock struct ptr to use
*
* Convert a clockdomain name stored in a struct clk 'clk' into a
* clockdomain pointer, and save it into the struct clk. Intended to be
- * called during clk_register(). No return value.
+ * called during clk_register(). Returns 0 on success or -ENOENT if the
+ * clockdomain is not found.
*/
-void omap2_init_clk_clkdm(struct clk *clk)
+static int _omap2_init_clk_clkdm(struct clk *clk)
{
struct clockdomain *clkdm;
+ int ret;
clkdm = clkdm_lookup(clk->clkdm.name);
if (clkdm) {
pr_debug("clock: associated clk %s to clkdm %s\n",
clk->name, clk->clkdm.name);
clk->clkdm.ptr = clkdm;
+ ret = 0;
} else {
pr_err("clock: %s: could not associate to clkdm %s\n",
clk->name, clk->clkdm.name);
+ ret = -ENOENT;
}
+
+ return ret;
}
/**
@@ -1082,12 +1088,5 @@ void omap2_clk_disable_unused(struct clk *clk)
int omap2_clk_register(struct clk *clk)
{
- if (!clk->clkdm.name) {
- pr_debug("clock: %s: missing clockdomain", clk->name);
- WARN_ON(1);
- return -EINVAL;
- }
-
- omap2_init_clk_clkdm(clk);
- return 0;
+ return _omap2_init_clk_clkdm(clk);
}
--
1.6.0.2.GIT
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