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 [email protected]....$.. ...
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 <[email protected]>
Signed-off-by: Suman Anna <[email protected]>
---
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
On 03/27/2018 05:52 AM, Suman Anna wrote:
> 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 [email protected]....$.. ...
> 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 <[email protected]>
Acked, I'm aware of the false-postive one, this is good to fix both one,
thanks~
Cheers,
Zumeng
> Signed-off-by: Suman Anna <[email protected]>
> ---
> 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;
> }
On 26-03-18, 16:52, Suman Anna wrote:
> 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
I don't agree to this reasoning for this particular patch. The code is just fine
and kmemleak is something that requires a fix.
> 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.
Maybe that could have been fixed in a separate patch, cc'ing stable kernels as
well.
> 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 [email protected]....$.. ...
> 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 <[email protected]>
> Signed-off-by: Suman Anna <[email protected]>
> ---
> 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;
> }
I am fine with the diff though, as that makes sense. So maybe do this ?
- send separate patch for ENODEV thing
- and another patch to move to devres with a different reason than fixing false
positive.
--
viresh
Hi Viresh,
On 04/02/2018 01:32 AM, Viresh Kumar wrote:
> On 26-03-18, 16:52, Suman Anna wrote:
>> 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
>
> I don't agree to this reasoning for this particular patch. The code is just fine
> and kmemleak is something that requires a fix.
>
>> 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.
>
> Maybe that could have been fixed in a separate patch, cc'ing stable kernels as
> well.
>
>> 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 [email protected]....$.. ...
>> 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 <[email protected]>
>> Signed-off-by: Suman Anna <[email protected]>
>> ---
>> 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;
>> }
>
> I am fine with the diff though, as that makes sense. So maybe do this ?
>
> - send separate patch for ENODEV thing
> - and another patch to move to devres with a different reason than fixing false
> positive
OK, thanks for your comments. Will split this patch and post the new
patches.
regards
Suman