* [PATCH] mfd: syscon: Don't free allocated name for regmap_config
@ 2020-09-03 16:02 ` Marc Zyngier
0 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-03 16:02 UTC (permalink / raw)
To: linux-kernel, linux-arm-kernel; +Cc: kernel-team, Lee Jones, Arnd Bergmann
The name allocated for the regmap_config structure is freed
pretty early, right after the registration of the MMIO region.
Unfortunately, that doesn't follow the life cycle that debugfs
expects, as it can access the name field long after the free
has occured.
Move the free on the error path, and keep it forever otherwise.
Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/mfd/syscon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index 75859e492984..7a660411c562 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
syscon_config.max_register = resource_size(&res) - reg_io_width;
regmap = regmap_init_mmio(NULL, base, &syscon_config);
- kfree(syscon_config.name);
if (IS_ERR(regmap)) {
pr_err("regmap init failed\n");
ret = PTR_ERR(regmap);
@@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
regmap_exit(regmap);
err_regmap:
iounmap(base);
+ kfree(syscon_config.name);
err_map:
kfree(syscon);
return ERR_PTR(ret);
--
2.27.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
2020-09-03 16:02 ` Marc Zyngier
@ 2020-09-08 8:22 ` Lee Jones
-1 siblings, 0 replies; 14+ messages in thread
From: Lee Jones @ 2020-09-08 8:22 UTC (permalink / raw)
To: Marc Zyngier
Cc: linux-kernel, linux-arm-kernel, Arnd Bergmann, Suman Anna, kernel-team
On Thu, 03 Sep 2020, Marc Zyngier wrote:
> The name allocated for the regmap_config structure is freed
> pretty early, right after the registration of the MMIO region.
>
> Unfortunately, that doesn't follow the life cycle that debugfs
> expects, as it can access the name field long after the free
> has occured.
>
> Move the free on the error path, and keep it forever otherwise.
>
> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/mfd/syscon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Does this work for you Suman, Arnd?
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index 75859e492984..7a660411c562 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> syscon_config.max_register = resource_size(&res) - reg_io_width;
>
> regmap = regmap_init_mmio(NULL, base, &syscon_config);
> - kfree(syscon_config.name);
> if (IS_ERR(regmap)) {
> pr_err("regmap init failed\n");
> ret = PTR_ERR(regmap);
> @@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> regmap_exit(regmap);
> err_regmap:
> iounmap(base);
> + kfree(syscon_config.name);
> err_map:
> kfree(syscon);
> return ERR_PTR(ret);
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
@ 2020-09-08 8:22 ` Lee Jones
0 siblings, 0 replies; 14+ messages in thread
From: Lee Jones @ 2020-09-08 8:22 UTC (permalink / raw)
To: Marc Zyngier; +Cc: kernel-team, Arnd Bergmann, linux-kernel, linux-arm-kernel
On Thu, 03 Sep 2020, Marc Zyngier wrote:
> The name allocated for the regmap_config structure is freed
> pretty early, right after the registration of the MMIO region.
>
> Unfortunately, that doesn't follow the life cycle that debugfs
> expects, as it can access the name field long after the free
> has occured.
>
> Move the free on the error path, and keep it forever otherwise.
>
> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/mfd/syscon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Does this work for you Suman, Arnd?
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index 75859e492984..7a660411c562 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> syscon_config.max_register = resource_size(&res) - reg_io_width;
>
> regmap = regmap_init_mmio(NULL, base, &syscon_config);
> - kfree(syscon_config.name);
> if (IS_ERR(regmap)) {
> pr_err("regmap init failed\n");
> ret = PTR_ERR(regmap);
> @@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> regmap_exit(regmap);
> err_regmap:
> iounmap(base);
> + kfree(syscon_config.name);
> err_map:
> kfree(syscon);
> return ERR_PTR(ret);
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
2020-09-03 16:02 ` Marc Zyngier
@ 2020-09-24 12:39 ` Lee Jones
-1 siblings, 0 replies; 14+ messages in thread
From: Lee Jones @ 2020-09-24 12:39 UTC (permalink / raw)
To: Marc Zyngier
Cc: linux-kernel, linux-arm-kernel, Arnd Bergmann, Suman Anna, kernel-team
On Thu, 03 Sep 2020, Marc Zyngier wrote:
> The name allocated for the regmap_config structure is freed
> pretty early, right after the registration of the MMIO region.
>
> Unfortunately, that doesn't follow the life cycle that debugfs
> expects, as it can access the name field long after the free
> has occured.
>
> Move the free on the error path, and keep it forever otherwise.
>
> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/mfd/syscon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Fixed the spelling mistake and applied, thanks.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
@ 2020-09-24 12:39 ` Lee Jones
0 siblings, 0 replies; 14+ messages in thread
From: Lee Jones @ 2020-09-24 12:39 UTC (permalink / raw)
To: Marc Zyngier; +Cc: kernel-team, Arnd Bergmann, linux-kernel, linux-arm-kernel
On Thu, 03 Sep 2020, Marc Zyngier wrote:
> The name allocated for the regmap_config structure is freed
> pretty early, right after the registration of the MMIO region.
>
> Unfortunately, that doesn't follow the life cycle that debugfs
> expects, as it can access the name field long after the free
> has occured.
>
> Move the free on the error path, and keep it forever otherwise.
>
> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/mfd/syscon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Fixed the spelling mistake and applied, thanks.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
2020-09-24 12:39 ` Lee Jones
@ 2020-09-26 0:28 ` Suman Anna
-1 siblings, 0 replies; 14+ messages in thread
From: Suman Anna @ 2020-09-26 0:28 UTC (permalink / raw)
To: Lee Jones, Marc Zyngier
Cc: linux-kernel, linux-arm-kernel, Arnd Bergmann, kernel-team
On 9/24/20 7:39 AM, Lee Jones wrote:
> On Thu, 03 Sep 2020, Marc Zyngier wrote:
>
>> The name allocated for the regmap_config structure is freed
>> pretty early, right after the registration of the MMIO region.
>>
>> Unfortunately, that doesn't follow the life cycle that debugfs
>> expects, as it can access the name field long after the free
>> has occured.
>>
>> Move the free on the error path, and keep it forever otherwise.
>>
>> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>> drivers/mfd/syscon.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Fixed the spelling mistake and applied, thanks.
>
Marc,
Can you recheck the behavior once on the latest master to see if this patch is
still needed? I see a new patch within the regmap core that is dealing with the
delayed debugfs registration name. This follows the similar design logic I
suggested on your initial submission [1].
Please see commit 94cc89eb8fa5 ("regmap: debugfs: Fix handling of name string
for debugfs init delays") in mainline.
Lee,
I haven't seen this patch in -next yet, so maybe worthwhile to hold it a little
longer.
regards
Suman
[1] https://patchwork.kernel.org/comment/23575471/
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
@ 2020-09-26 0:28 ` Suman Anna
0 siblings, 0 replies; 14+ messages in thread
From: Suman Anna @ 2020-09-26 0:28 UTC (permalink / raw)
To: Lee Jones, Marc Zyngier
Cc: kernel-team, Arnd Bergmann, linux-kernel, linux-arm-kernel
On 9/24/20 7:39 AM, Lee Jones wrote:
> On Thu, 03 Sep 2020, Marc Zyngier wrote:
>
>> The name allocated for the regmap_config structure is freed
>> pretty early, right after the registration of the MMIO region.
>>
>> Unfortunately, that doesn't follow the life cycle that debugfs
>> expects, as it can access the name field long after the free
>> has occured.
>>
>> Move the free on the error path, and keep it forever otherwise.
>>
>> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>> drivers/mfd/syscon.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Fixed the spelling mistake and applied, thanks.
>
Marc,
Can you recheck the behavior once on the latest master to see if this patch is
still needed? I see a new patch within the regmap core that is dealing with the
delayed debugfs registration name. This follows the similar design logic I
suggested on your initial submission [1].
Please see commit 94cc89eb8fa5 ("regmap: debugfs: Fix handling of name string
for debugfs init delays") in mainline.
Lee,
I haven't seen this patch in -next yet, so maybe worthwhile to hold it a little
longer.
regards
Suman
[1] https://patchwork.kernel.org/comment/23575471/
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
2020-09-26 0:28 ` Suman Anna
@ 2020-09-28 9:19 ` Lee Jones
-1 siblings, 0 replies; 14+ messages in thread
From: Lee Jones @ 2020-09-28 9:19 UTC (permalink / raw)
To: Suman Anna
Cc: Marc Zyngier, linux-kernel, linux-arm-kernel, Arnd Bergmann, kernel-team
On Fri, 25 Sep 2020, Suman Anna wrote:
> On 9/24/20 7:39 AM, Lee Jones wrote:
> > On Thu, 03 Sep 2020, Marc Zyngier wrote:
> >
> >> The name allocated for the regmap_config structure is freed
> >> pretty early, right after the registration of the MMIO region.
> >>
> >> Unfortunately, that doesn't follow the life cycle that debugfs
> >> expects, as it can access the name field long after the free
> >> has occured.
> >>
> >> Move the free on the error path, and keep it forever otherwise.
> >>
> >> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> >> Signed-off-by: Marc Zyngier <maz@kernel.org>
> >> ---
> >> drivers/mfd/syscon.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Fixed the spelling mistake and applied, thanks.
> >
>
> Marc,
> Can you recheck the behavior once on the latest master to see if this patch is
> still needed? I see a new patch within the regmap core that is dealing with the
> delayed debugfs registration name. This follows the similar design logic I
> suggested on your initial submission [1].
>
> Please see commit 94cc89eb8fa5 ("regmap: debugfs: Fix handling of name string
> for debugfs init delays") in mainline.
>
> Lee,
> I haven't seen this patch in -next yet, so maybe worthwhile to hold it a little
> longer.
It's already applied.
If the lines become superfluous please submit a subsequent patch.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
@ 2020-09-28 9:19 ` Lee Jones
0 siblings, 0 replies; 14+ messages in thread
From: Lee Jones @ 2020-09-28 9:19 UTC (permalink / raw)
To: Suman Anna
Cc: Marc Zyngier, kernel-team, Arnd Bergmann, linux-kernel, linux-arm-kernel
On Fri, 25 Sep 2020, Suman Anna wrote:
> On 9/24/20 7:39 AM, Lee Jones wrote:
> > On Thu, 03 Sep 2020, Marc Zyngier wrote:
> >
> >> The name allocated for the regmap_config structure is freed
> >> pretty early, right after the registration of the MMIO region.
> >>
> >> Unfortunately, that doesn't follow the life cycle that debugfs
> >> expects, as it can access the name field long after the free
> >> has occured.
> >>
> >> Move the free on the error path, and keep it forever otherwise.
> >>
> >> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> >> Signed-off-by: Marc Zyngier <maz@kernel.org>
> >> ---
> >> drivers/mfd/syscon.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Fixed the spelling mistake and applied, thanks.
> >
>
> Marc,
> Can you recheck the behavior once on the latest master to see if this patch is
> still needed? I see a new patch within the regmap core that is dealing with the
> delayed debugfs registration name. This follows the similar design logic I
> suggested on your initial submission [1].
>
> Please see commit 94cc89eb8fa5 ("regmap: debugfs: Fix handling of name string
> for debugfs init delays") in mainline.
>
> Lee,
> I haven't seen this patch in -next yet, so maybe worthwhile to hold it a little
> longer.
It's already applied.
If the lines become superfluous please submit a subsequent patch.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
2020-09-03 16:02 ` Marc Zyngier
@ 2021-02-16 6:34 ` Tomi Valkeinen
-1 siblings, 0 replies; 14+ messages in thread
From: Tomi Valkeinen @ 2021-02-16 6:34 UTC (permalink / raw)
To: Marc Zyngier, linux-kernel, linux-arm-kernel
Cc: kernel-team, Lee Jones, Arnd Bergmann, Suman Anna
Hi Marc,
On 03/09/2020 19:02, Marc Zyngier wrote:
> The name allocated for the regmap_config structure is freed
> pretty early, right after the registration of the MMIO region.
>
> Unfortunately, that doesn't follow the life cycle that debugfs
> expects, as it can access the name field long after the free
> has occured.
>
> Move the free on the error path, and keep it forever otherwise.
>
> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/mfd/syscon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index 75859e492984..7a660411c562 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> syscon_config.max_register = resource_size(&res) - reg_io_width;
>
> regmap = regmap_init_mmio(NULL, base, &syscon_config);
> - kfree(syscon_config.name);
> if (IS_ERR(regmap)) {
> pr_err("regmap init failed\n");
> ret = PTR_ERR(regmap);
> @@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> regmap_exit(regmap);
> err_regmap:
> iounmap(base);
> + kfree(syscon_config.name);
> err_map:
> kfree(syscon);
> return ERR_PTR(ret);
>
This patch causes lots of kmemleak reports, for example:
unreferenced object 0xc8e6f000 (size 64):
comm "kworker/1:1", pid 22, jiffies 4294938454 (age 95.540s)
hex dump (first 32 bytes):
64 73 70 5f 73 79 73 74 65 6d 40 34 30 64 30 30 dsp_system@40d00
30 30 30 00 e0 09 4d c1 ac 1b 4d c1 64 74 4c c1 000...M...M.dtL.
backtrace:
[<(ptrval)>] __kmalloc_track_caller+0x2bc/0x418
[<(ptrval)>] kvasprintf+0x9c/0x124
[<(ptrval)>] kasprintf+0x70/0xac
[<(ptrval)>] of_syscon_register+0x1f0/0x4f0
[<(ptrval)>] device_node_get_regmap+0x12c/0x158
[<(ptrval)>] syscon_regmap_lookup_by_phandle+0x5c/0x6c
[<(ptrval)>] omap_iommu_probe+0x6ac/0xc28
[<(ptrval)>] platform_probe+0x120/0x1e0
[<(ptrval)>] really_probe+0x2b4/0x121c
[<(ptrval)>] driver_probe_device+0x10c/0x4c0
[<(ptrval)>] __device_attach_driver+0x1d8/0x26c
[<(ptrval)>] bus_for_each_drv+0x174/0x200
[<(ptrval)>] __device_attach+0x2f0/0x45c
[<(ptrval)>] device_initial_probe+0x1c/0x20
[<(ptrval)>] bus_probe_device+0x224/0x2b8
[<(ptrval)>] device_add+0xad0/0x1e18
Tomi
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
@ 2021-02-16 6:34 ` Tomi Valkeinen
0 siblings, 0 replies; 14+ messages in thread
From: Tomi Valkeinen @ 2021-02-16 6:34 UTC (permalink / raw)
To: Marc Zyngier, linux-kernel, linux-arm-kernel
Cc: Lee Jones, Suman Anna, kernel-team, Arnd Bergmann
Hi Marc,
On 03/09/2020 19:02, Marc Zyngier wrote:
> The name allocated for the regmap_config structure is freed
> pretty early, right after the registration of the MMIO region.
>
> Unfortunately, that doesn't follow the life cycle that debugfs
> expects, as it can access the name field long after the free
> has occured.
>
> Move the free on the error path, and keep it forever otherwise.
>
> Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/mfd/syscon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index 75859e492984..7a660411c562 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> syscon_config.max_register = resource_size(&res) - reg_io_width;
>
> regmap = regmap_init_mmio(NULL, base, &syscon_config);
> - kfree(syscon_config.name);
> if (IS_ERR(regmap)) {
> pr_err("regmap init failed\n");
> ret = PTR_ERR(regmap);
> @@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> regmap_exit(regmap);
> err_regmap:
> iounmap(base);
> + kfree(syscon_config.name);
> err_map:
> kfree(syscon);
> return ERR_PTR(ret);
>
This patch causes lots of kmemleak reports, for example:
unreferenced object 0xc8e6f000 (size 64):
comm "kworker/1:1", pid 22, jiffies 4294938454 (age 95.540s)
hex dump (first 32 bytes):
64 73 70 5f 73 79 73 74 65 6d 40 34 30 64 30 30 dsp_system@40d00
30 30 30 00 e0 09 4d c1 ac 1b 4d c1 64 74 4c c1 000...M...M.dtL.
backtrace:
[<(ptrval)>] __kmalloc_track_caller+0x2bc/0x418
[<(ptrval)>] kvasprintf+0x9c/0x124
[<(ptrval)>] kasprintf+0x70/0xac
[<(ptrval)>] of_syscon_register+0x1f0/0x4f0
[<(ptrval)>] device_node_get_regmap+0x12c/0x158
[<(ptrval)>] syscon_regmap_lookup_by_phandle+0x5c/0x6c
[<(ptrval)>] omap_iommu_probe+0x6ac/0xc28
[<(ptrval)>] platform_probe+0x120/0x1e0
[<(ptrval)>] really_probe+0x2b4/0x121c
[<(ptrval)>] driver_probe_device+0x10c/0x4c0
[<(ptrval)>] __device_attach_driver+0x1d8/0x26c
[<(ptrval)>] bus_for_each_drv+0x174/0x200
[<(ptrval)>] __device_attach+0x2f0/0x45c
[<(ptrval)>] device_initial_probe+0x1c/0x20
[<(ptrval)>] bus_probe_device+0x224/0x2b8
[<(ptrval)>] device_add+0xad0/0x1e18
Tomi
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
2021-02-16 6:34 ` Tomi Valkeinen
@ 2021-02-16 8:42 ` Marc Zyngier
-1 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2021-02-16 8:42 UTC (permalink / raw)
To: Tomi Valkeinen
Cc: linux-kernel, linux-arm-kernel, kernel-team, Lee Jones,
Arnd Bergmann, Suman Anna
Hi Tomi,
On Tue, 16 Feb 2021 06:34:50 +0000,
Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> wrote:
>
> Hi Marc,
>
> On 03/09/2020 19:02, Marc Zyngier wrote:
> > The name allocated for the regmap_config structure is freed
> > pretty early, right after the registration of the MMIO region.
> >
> > Unfortunately, that doesn't follow the life cycle that debugfs
> > expects, as it can access the name field long after the free
> > has occured.
> >
> > Move the free on the error path, and keep it forever otherwise.
> >
> > Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > ---
> > drivers/mfd/syscon.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> > index 75859e492984..7a660411c562 100644
> > --- a/drivers/mfd/syscon.c
> > +++ b/drivers/mfd/syscon.c
> > @@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> > syscon_config.max_register = resource_size(&res) - reg_io_width;
> >
> > regmap = regmap_init_mmio(NULL, base, &syscon_config);
> > - kfree(syscon_config.name);
> > if (IS_ERR(regmap)) {
> > pr_err("regmap init failed\n");
> > ret = PTR_ERR(regmap);
> > @@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> > regmap_exit(regmap);
> > err_regmap:
> > iounmap(base);
> > + kfree(syscon_config.name);
> > err_map:
> > kfree(syscon);
> > return ERR_PTR(ret);
> >
>
> This patch causes lots of kmemleak reports, for example:
It may trigger some kmemleak reports, but at the time it was written,
this patch avoided some very nasty memory corruption with debugfs. The
problem is that the memory management responsibilities between syscon,
regmap and debugfs are rather obscure.
If you can come up with an accurate description of the life cycle of
syscon_config.name across these 3 subsystems, we may be able to fix it
for good.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH] mfd: syscon: Don't free allocated name for regmap_config
@ 2021-02-16 8:42 ` Marc Zyngier
0 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2021-02-16 8:42 UTC (permalink / raw)
To: Tomi Valkeinen
Cc: Arnd Bergmann, kernel-team, linux-kernel, Suman Anna, Lee Jones,
linux-arm-kernel
Hi Tomi,
On Tue, 16 Feb 2021 06:34:50 +0000,
Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> wrote:
>
> Hi Marc,
>
> On 03/09/2020 19:02, Marc Zyngier wrote:
> > The name allocated for the regmap_config structure is freed
> > pretty early, right after the registration of the MMIO region.
> >
> > Unfortunately, that doesn't follow the life cycle that debugfs
> > expects, as it can access the name field long after the free
> > has occured.
> >
> > Move the free on the error path, and keep it forever otherwise.
> >
> > Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > ---
> > drivers/mfd/syscon.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> > index 75859e492984..7a660411c562 100644
> > --- a/drivers/mfd/syscon.c
> > +++ b/drivers/mfd/syscon.c
> > @@ -108,7 +108,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> > syscon_config.max_register = resource_size(&res) - reg_io_width;
> >
> > regmap = regmap_init_mmio(NULL, base, &syscon_config);
> > - kfree(syscon_config.name);
> > if (IS_ERR(regmap)) {
> > pr_err("regmap init failed\n");
> > ret = PTR_ERR(regmap);
> > @@ -145,6 +144,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
> > regmap_exit(regmap);
> > err_regmap:
> > iounmap(base);
> > + kfree(syscon_config.name);
> > err_map:
> > kfree(syscon);
> > return ERR_PTR(ret);
> >
>
> This patch causes lots of kmemleak reports, for example:
It may trigger some kmemleak reports, but at the time it was written,
this patch avoided some very nasty memory corruption with debugfs. The
problem is that the memory management responsibilities between syscon,
regmap and debugfs are rather obscure.
If you can come up with an accurate description of the life cycle of
syscon_config.name across these 3 subsystems, we may be able to fix it
for good.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread