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authorHenrik Rydberg <rydberg@euromail.se>2013-09-26 08:33:16 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-05 07:13:12 -0700
commit332769e13b075c82ae7b9f79be29506f8c6aceb2 (patch)
treebf4b30ebf211f38949cad43daa102a3c1fb2c372 /drivers/hwmon
parent37482f9cfb0269e082a817f31ad2a5f0204163f9 (diff)
hwmon: (applesmc) Check key count before proceeding
commit 5f4513864304672e6ea9eac60583eeac32e679f2 upstream. After reports from Chris and Josh Boyer of a rare crash in applesmc, Guenter pointed at the initialization problem fixed below. The patch has not been verified to fix the crash, but should be applied regardless. Reported-by: <jwboyer@fedoraproject.org> Suggested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/applesmc.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index 62c2e32e25e..98814d12a60 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -525,16 +525,25 @@ static int applesmc_init_smcreg_try(void)
{
struct applesmc_registers *s = &smcreg;
bool left_light_sensor, right_light_sensor;
+ unsigned int count;
u8 tmp[1];
int ret;
if (s->init_complete)
return 0;
- ret = read_register_count(&s->key_count);
+ ret = read_register_count(&count);
if (ret)
return ret;
+ if (s->cache && s->key_count != count) {
+ pr_warn("key count changed from %d to %d\n",
+ s->key_count, count);
+ kfree(s->cache);
+ s->cache = NULL;
+ }
+ s->key_count = count;
+
if (!s->cache)
s->cache = kcalloc(s->key_count, sizeof(*s->cache), GFP_KERNEL);
if (!s->cache)