OMAP: powerdomain: Fix overflow when doing powerdomain deps lookups.

At the end of the list pd is a pointer to a NULL struct, so checking
if the address == NULL doesn't help here. In fact the original code
will just keep running past the struct to read who knows what in
memory.

This case manifests itself when from clkdms_setup() when enabling auto
idle for a clock domain and the clockdomain usecount is greater than
0. When _clkdm_add_autodeps() tries to add the a dependency that does
not exist in the powerdomain->wkdep_srcs array the for loop will run
past the wkdep_srcs array.

Currently in linux-omap you won't hit this because the not found case
is never executed, unless you start modifying powerdomains and their
wakeup/sleep deps.

Signed-off-by: Mike Chan <mike@android.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>

diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index 983f1cb..66206b6 100644 (file)
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -83,7 +83,7 @@ static struct powerdomain *_pwrdm_deps_lookup(struct powerdomain *pwrdm,
        if (!pwrdm || !deps || !omap_chip_is(pwrdm->omap_chip))
                return ERR_PTR(-EINVAL);
 
-       for (pd = deps; pd; pd++) {
+       for (pd = deps; pd->pwrdm_name; pd++) {
 
                if (!omap_chip_is(pd->omap_chip))
                        continue;
@@ -96,7 +96,7 @@ static struct powerdomain *_pwrdm_deps_lookup(struct powerdomain *pwrdm,
 
        }
 
-       if (!pd)
+       if (!pd->pwrdm_name)
                return ERR_PTR(-ENOENT);
 
        return pd->pwrdm;