2021-09-06 04:21:59

by Zenghui Yu

Subject: [PATCH] drm/i915: Free the returned object of acpi_evaluate_dsm()

As per the comment on top of acpi_evaluate_dsm():

| * Evaluate device's _DSM method with specified GUID, revision id and
| * function number. Caller needs to free the returned object.

We should free the returned object of acpi_evaluate_dsm() to avoid memory
leakage. Otherwise the kmemleak splat will be triggered at boot time (if we
compile kernel with CONFIG_DEBUG_TEST_DRIVER_REMOVE=y).

Fixes: 8e55f99c510f ("drm/i915: Invoke another _DSM to enable MUX on HP Workstation laptops")
Cc: Kai-Heng Feng <[email protected]>
Signed-off-by: Zenghui Yu <[email protected]>
---
drivers/gpu/drm/i915/display/intel_acpi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
index 7cfe91fc05f2..68abeaf2d7d4 100644
--- a/drivers/gpu/drm/i915/display/intel_acpi.c
+++ b/drivers/gpu/drm/i915/display/intel_acpi.c
@@ -186,13 +186,16 @@ void intel_dsm_get_bios_data_funcs_supported(struct drm_i915_private *i915)
{
struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
acpi_handle dhandle;
+ union acpi_object *obj;

dhandle = ACPI_HANDLE(&pdev->dev);
if (!dhandle)
return;

- acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
- INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
+ obj = acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
+ INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
+ if (obj)
+ ACPI_FREE(obj);
}

/*
--
2.19.1

2021-10-07 09:50:51

by Zenghui Yu

Subject: Re: [PATCH] drm/i915: Free the returned object of acpi_evaluate_dsm()

[+linux-acpi]

ping

On 2021/9/6 11:35, Zenghui Yu wrote:
> As per the comment on top of acpi_evaluate_dsm():
>
> | * Evaluate device's _DSM method with specified GUID, revision id and
> | * function number. Caller needs to free the returned object.
>
> We should free the returned object of acpi_evaluate_dsm() to avoid memory
> leakage. Otherwise the kmemleak splat will be triggered at boot time (if we
> compile kernel with CONFIG_DEBUG_TEST_DRIVER_REMOVE=y).
>
> Fixes: 8e55f99c510f ("drm/i915: Invoke another _DSM to enable MUX on HP Workstation laptops")
> Cc: Kai-Heng Feng <[email protected]>
> Signed-off-by: Zenghui Yu <[email protected]>
> ---
> drivers/gpu/drm/i915/display/intel_acpi.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
> index 7cfe91fc05f2..68abeaf2d7d4 100644
> --- a/drivers/gpu/drm/i915/display/intel_acpi.c
> +++ b/drivers/gpu/drm/i915/display/intel_acpi.c
> @@ -186,13 +186,16 @@ void intel_dsm_get_bios_data_funcs_supported(struct drm_i915_private *i915)
> {
> struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> acpi_handle dhandle;
> + union acpi_object *obj;
>
> dhandle = ACPI_HANDLE(&pdev->dev);
> if (!dhandle)
> return;
>
> - acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
> - INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
> + obj = acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
> + INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
> + if (obj)
> + ACPI_FREE(obj);
> }
>
> /*
>

2021-10-07 10:16:13

by Ville Syrjälä

Subject: Re: [PATCH] drm/i915: Free the returned object of acpi_evaluate_dsm()

On Mon, Sep 06, 2021 at 11:35:41AM +0800, Zenghui Yu wrote:
> As per the comment on top of acpi_evaluate_dsm():
>
> | * Evaluate device's _DSM method with specified GUID, revision id and
> | * function number. Caller needs to free the returned object.
>
> We should free the returned object of acpi_evaluate_dsm() to avoid memory
> leakage. Otherwise the kmemleak splat will be triggered at boot time (if we
> compile kernel with CONFIG_DEBUG_TEST_DRIVER_REMOVE=y).
>
> Fixes: 8e55f99c510f ("drm/i915: Invoke another _DSM to enable MUX on HP Workstation laptops")
> Cc: Kai-Heng Feng <[email protected]>
> Signed-off-by: Zenghui Yu <[email protected]>

Applied to drm-intel-next. Thanks, and sorry for the lag.

> ---
> drivers/gpu/drm/i915/display/intel_acpi.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
> index 7cfe91fc05f2..68abeaf2d7d4 100644
> --- a/drivers/gpu/drm/i915/display/intel_acpi.c
> +++ b/drivers/gpu/drm/i915/display/intel_acpi.c
> @@ -186,13 +186,16 @@ void intel_dsm_get_bios_data_funcs_supported(struct drm_i915_private *i915)
> {
> struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> acpi_handle dhandle;
> + union acpi_object *obj;
>
> dhandle = ACPI_HANDLE(&pdev->dev);
> if (!dhandle)
> return;
>
> - acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
> - INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
> + obj = acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
> + INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
> + if (obj)
> + ACPI_FREE(obj);
> }
>
> /*
> --
> 2.19.1

--
Ville Syrj?l?
Intel