| From 10470dec3decaf5ed3c596f85debd7c42777ae12 Mon Sep 17 00:00:00 2001 |
| From: Ivan Kokshaysky <ink@jurassic.park.msu.ru> |
| Date: Sat, 20 Jun 2020 17:44:49 +0100 |
| Subject: cpufreq: dt: fix oops on armada37xx |
| |
| From: Ivan Kokshaysky <ink@jurassic.park.msu.ru> |
| |
| commit 10470dec3decaf5ed3c596f85debd7c42777ae12 upstream. |
| |
| Commit 0c868627e617e43a295d8 (cpufreq: dt: Allow platform specific |
| intermediate callbacks) added two function pointers to the |
| struct cpufreq_dt_platform_data. However, armada37xx_cpufreq_driver_init() |
| has this struct (pdata) located on the stack and uses only "suspend" |
| and "resume" fields. So these newly added "get_intermediate" and |
| "target_intermediate" pointers are uninitialized and contain arbitrary |
| non-null values, causing all kinds of trouble. |
| |
| For instance, here is an oops on espressobin after an attempt to change |
| the cpefreq governor: |
| |
| [ 29.174554] Unable to handle kernel execute from non-executable memory at virtual address ffff00003f87bdc0 |
| ... |
| [ 29.269373] pc : 0xffff00003f87bdc0 |
| [ 29.272957] lr : __cpufreq_driver_target+0x138/0x580 |
| ... |
| |
| Fixed by zeroing out pdata before use. |
| |
| Cc: <stable@vger.kernel.org> # v5.7+ |
| Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> |
| Reviewed-by: Andrew Lunn <andrew@lunn.ch> |
| Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/cpufreq/armada-37xx-cpufreq.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| --- a/drivers/cpufreq/armada-37xx-cpufreq.c |
| +++ b/drivers/cpufreq/armada-37xx-cpufreq.c |
| @@ -456,6 +456,7 @@ static int __init armada37xx_cpufreq_dri |
| /* Now that everything is setup, enable the DVFS at hardware level */ |
| armada37xx_cpufreq_enable_dvfs(nb_pm_base); |
| |
| + memset(&pdata, 0, sizeof(pdata)); |
| pdata.suspend = armada37xx_cpufreq_suspend; |
| pdata.resume = armada37xx_cpufreq_resume; |
| |
