[PATCH] cpufreq: ti-cpufreq: Fix couple of minor issues in probe()

From: Suman Anna
Date: Mon Mar 26 2018 - 17:53:02 EST


Commit 05829d9431df ("cpufreq: ti-cpufreq: kfree opp_data when
failure") has fixed a memory leak in the failure path, however
kmemleak still keeps reporting a leak even on successful probes.
This is a false-positive and is mostly a result of the opp_data
variable not being stored anywhere in the probe function. The
patch also returned a positive value on the get_cpu_device()
failure instead of a negative value.

unreferenced object 0xecae4d80 (size 64):
comm "swapper/0", pid 1, jiffies 4294937673 (age 154.420s)
hex dump (first 32 bytes):
10 40 d9 ee 74 b7 db ee 00 24 ac ec 20 a3 ea c0 .@..t....$.. ...
00 26 ac ec 00 00 00 00 00 00 00 00 00 00 00 00 .&..............
backtrace:
[<ec080d62>] platform_drv_probe+0x50/0xac
[<cbde8566>] driver_probe_device+0x24c/0x330
[<a5818eb4>] bus_for_each_drv+0x54/0xb8
[<2c6f7021>] __device_attach+0xcc/0x13c
[<a04478a2>] bus_probe_device+0x88/0x90
[<b322c963>] device_add+0x38c/0x5b4
[<6f1af99b>] platform_device_add+0x100/0x220
[<cef42bca>] platform_device_register_full+0xf0/0x104
[<4d492439>] ti_cpufreq_init+0x44/0x6c
[<81222e89>] do_one_initcall+0x48/0x190
[<3bebf42a>] kernel_init_freeable+0x1f4/0x2b8
[<230ad7df>] kernel_init+0x8/0x110
[<43a165c3>] ret_from_fork+0x14/0x20
[< (null)>] (null)
[<87288797>] 0xffffffff

Fix both issues by replacing the previous logic by using the devres
managed API for allocating the opp_data variable, and simplifying
the get_cpu_device() failure return path.

Fixes: 05829d9431df ("cpufreq: ti-cpufreq: kfree opp_data when failure")
Cc: Zumeng Chen <zumeng.chen@xxxxxxxxx>
Signed-off-by: Suman Anna <s-anna@xxxxxx>
---
drivers/cpufreq/ti-cpufreq.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
index a099b7bf74cd..7d353a21935b 100644
--- a/drivers/cpufreq/ti-cpufreq.c
+++ b/drivers/cpufreq/ti-cpufreq.c
@@ -217,7 +217,7 @@ static int ti_cpufreq_probe(struct platform_device *pdev)
if (!match)
return -ENODEV;

- opp_data = kzalloc(sizeof(*opp_data), GFP_KERNEL);
+ opp_data = devm_kzalloc(&pdev->dev, sizeof(*opp_data), GFP_KERNEL);
if (!opp_data)
return -ENOMEM;

@@ -226,8 +226,7 @@ static int ti_cpufreq_probe(struct platform_device *pdev)
opp_data->cpu_dev = get_cpu_device(0);
if (!opp_data->cpu_dev) {
pr_err("%s: Failed to get device for CPU0\n", __func__);
- ret = ENODEV;
- goto free_opp_data;
+ return -ENODEV;
}

opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
@@ -285,8 +284,6 @@ static int ti_cpufreq_probe(struct platform_device *pdev)

fail_put_node:
of_node_put(opp_data->opp_node);
-free_opp_data:
- kfree(opp_data);

return ret;
}
--
2.16.2