2022-04-13 11:55:06

by baihaowen

[permalink] [raw]
Subject: [PATCH V2] clk: renesas: Fix memory leak of 'cpg'

Fix this issue by freeing the cpg when exiting the function in the
error/normal path.

Signed-off-by: Haowen Bai <[email protected]>
---
V1->V2: free both cpg&clks

drivers/clk/renesas/clk-r8a73a4.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/renesas/clk-r8a73a4.c b/drivers/clk/renesas/clk-r8a73a4.c
index cfed11c659d9..5a8d976f49e0 100644
--- a/drivers/clk/renesas/clk-r8a73a4.c
+++ b/drivers/clk/renesas/clk-r8a73a4.c
@@ -215,7 +215,7 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)

cpg->reg = of_iomap(np, 0);
if (WARN_ON(cpg->reg == NULL))
- return;
+ goto out_free_cpg;

for (i = 0; i < num_clks; ++i) {
const char *name;
@@ -233,6 +233,9 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
}

of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
+out_free_cpg:
+ kfree(cpg);
+ kfree(clks);
}
CLK_OF_DECLARE(r8a73a4_cpg_clks, "renesas,r8a73a4-cpg-clocks",
r8a73a4_cpg_clocks_init);
--
2.7.4


2022-04-13 20:29:00

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [PATCH V2] clk: renesas: Fix memory leak of 'cpg'

Hi Haowen,

On Wed, Apr 13, 2022 at 12:44 PM 白浩文 <[email protected]> wrote:
> But this function __init r8a73a4_cpg_clocks_init will auto free by system after boot

The memory containing the code for the function
r8a73a4_cpg_clocks_init() will indeed be freed. But the data
structures allocated and prepared by the function will continue to
exist afterwards.

> On Wed, Apr 13, 2022 at 11:24 AM baihaowen <[email protected]> wrote:
> > 在 4/13/22 4:41 PM, Geert Uytterhoeven 写道:
> > > On Wed, Apr 13, 2022 at 10:30 AM Haowen Bai <[email protected]> wrote:
> > >> Fix this issue by freeing the cpg when exiting the function in the
> > >> error/normal path.
> > >>
> > >> Signed-off-by: Haowen Bai <[email protected]>

> > >> --- a/drivers/clk/renesas/clk-r8a73a4.c
> > >> +++ b/drivers/clk/renesas/clk-r8a73a4.c
> > >> @@ -215,7 +215,7 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
> > >>
> > >> cpg->reg = of_iomap(np, 0);
> > >> if (WARN_ON(cpg->reg == NULL))
> > >> - return;
> > >> + goto out_free_cpg;
> > > Note that this is a fatal error, i.e. no chance the system will survive this,
> > > so cleaning up is moot.
> > >
> > >> for (i = 0; i < num_clks; ++i) {
> > >> const char *name;
> > >> @@ -233,6 +233,9 @@ static void __init r8a73a4_cpg_clocks_init(struct device_node *np)
> > >> }
> > >>
> > >> of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
> > >> +out_free_cpg:
> > >> + kfree(cpg);
> > >> + kfree(clks);
> > > Both cpg and clks are still used after returning from this function,
> > > through the registered clocks and clock provider.
> > >
> > >> }
> > >> CLK_OF_DECLARE(r8a73a4_cpg_clks, "renesas,r8a73a4-cpg-clocks",
> > >> r8a73a4_cpg_clocks_init);
> > > NAKed-by: Geert Uytterhoeven <[email protected]>
>
> > Could you show me how and when cpg & clks free ?
>
> They are never freed, as they stay in-use for the lifetime of the system.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2022-04-14 14:20:40

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [PATCH V2] clk: renesas: Fix memory leak of 'cpg'

Hi Sergei,

On Thu, Apr 14, 2022 at 11:29 AM Sergey Shtylyov <[email protected]> wrote:
> On 4/13/22 11:19 AM, Haowen Bai wrote:
> > Fix this issue by freeing the cpg when exiting the function in the
> > error/normal path.
> >
> > Signed-off-by: Haowen Bai <[email protected]>
> > ---
> > V1->V2: free both cpg&clks.
> >
> > drivers/clk/renesas/clk-r8a73a4.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
>
> 2 patches with the same name won't do -- you always need to include the chip name
> part of the file name in the subject (in this case r8a73a4).

Oh, they were for multiple drivers?
I hadn't even noticed , as Gmail collapsed them all into the same thread...

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2022-04-14 15:32:12

by baihaowen

[permalink] [raw]
Subject: Re: [PATCH V2] clk: renesas: Fix memory leak of 'cpg'

在 4/14/22 5:29 PM, Sergey Shtylyov 写道:
> Hello!
>
> On 4/13/22 11:19 AM, Haowen Bai wrote:
>
>> Fix this issue by freeing the cpg when exiting the function in the
>> error/normal path.
>>
>> Signed-off-by: Haowen Bai <[email protected]>
>> ---
>> V1->V2: free both cpg&clks.
>>
>> drivers/clk/renesas/clk-r8a73a4.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
> 2 patches with the same name won't do -- you always need to include the chip name
> part of the file name in the subject (in this case r8a73a4).
>
> MBR, Sergey
Got it, thank you for your kindly reminder.

--
Haowen Bai

2022-04-15 08:42:11

by Sergey Shtylyov

[permalink] [raw]
Subject: Re: [PATCH V2] clk: renesas: Fix memory leak of 'cpg'

On 4/14/22 12:32 PM, Geert Uytterhoeven wrote:

[...]
>>> Fix this issue by freeing the cpg when exiting the function in the
>>> error/normal path.
>>>
>>> Signed-off-by: Haowen Bai <[email protected]>
>>> ---
>>> V1->V2: free both cpg&clks.
>>>
>>> drivers/clk/renesas/clk-r8a73a4.c | 5 ++++-
>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> 2 patches with the same name won't do -- you always need to include the chip name
>> part of the file name in the subject (in this case r8a73a4).
>
> Oh, they were for multiple drivers?

I counted 3! :-)

> I hadn't even noticed , as Gmail collapsed them all into the same thread...

Hm, they weren't actually posted in the same thread...

> Gr{oetje,eeting}s,
>
> Geert
[...]

MBR, Sergey