2008-06-07 01:15:08

by Chris Wright

[permalink] [raw]
Subject: [patch 50/50] cpufreq: fix null object access on Transmeta CPU

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: CHIKAMA masaki <[email protected]>

upstream commit: 879000f94442860e72c934f9e568989bc7fb8ec4

If cpu specific cpufreq driver(i.e. longrun) has "setpolicy" function,
governor object isn't set into cpufreq_policy object at "__cpufreq_set_policy"
function in driver/cpufreq/cpufreq.c .

This causes a null object access at "store_scaling_setspeed" and
"show_scaling_setspeed" function in driver/cpufreq/cpufreq.c when reading or
writing through /sys interface (ex. cat
/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed)

Addresses:
http://bugzilla.kernel.org/show_bug.cgi?id=10654
https://bugzilla.redhat.com/show_bug.cgi?id=443354

Signed-off-by: CHIKAMA Masaki <[email protected]>
Cc: Dave Jones <[email protected]>
Cc: Chuck Ebbert <[email protected]>
Acked-by: Dominik Brodowski <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
drivers/cpufreq/cpufreq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -607,7 +607,7 @@ static ssize_t store_scaling_setspeed(st
unsigned int freq = 0;
unsigned int ret;

- if (!policy->governor->store_setspeed)
+ if (!policy->governor || !policy->governor->store_setspeed)
return -EINVAL;

ret = sscanf(buf, "%u", &freq);
@@ -621,7 +621,7 @@ static ssize_t store_scaling_setspeed(st

static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
{
- if (!policy->governor->show_setspeed)
+ if (!policy->governor || !policy->governor->show_setspeed)
return sprintf(buf, "<unsupported>\n");

return policy->governor->show_setspeed(policy, buf);

--