2010-08-17 23:48:46

by Jin Dongming

Subject: [PATCH 2/2][Patch-next -v2] ACPI, APEI, HEST Fix the unsuitable usage of platform_data.

platform_data in hest_parse_ghes() is used for saving the address of entry
information of erst_tab. When the device is failed to be added, platform_data
will be freed by platform_device_put(). But the value saved in platform_data
should not be freed here. If it is done, it will make system panic.

So I think platform_data should save the address of allocated memory
which saves entry information of erst_tab.

This patch fixed it and I confirmed it on x86_64 next-tree.

Signed-off-by: Jin Dongming <[email protected]>
---
drivers/acpi/apei/ghes.c | 2 +-
drivers/acpi/apei/hest.c | 11 +++++++----
2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 385a605..0d505e5 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -302,7 +302,7 @@ static int __devinit ghes_probe(struct platform_device *ghes_dev)
struct ghes *ghes = NULL;
int rc = -EINVAL;

- generic = ghes_dev->dev.platform_data;
+ generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
if (!generic->enabled)
return -ENODEV;

diff --git a/drivers/acpi/apei/hest.c b/drivers/acpi/apei/hest.c
index 343168d..1a3508a 100644
--- a/drivers/acpi/apei/hest.c
+++ b/drivers/acpi/apei/hest.c
@@ -137,20 +137,23 @@ static int hest_parse_ghes_count(struct acpi_hest_header *hest_hdr, void *data)

static int hest_parse_ghes(struct acpi_hest_header *hest_hdr, void *data)
{
- struct acpi_hest_generic *generic;
struct platform_device *ghes_dev;
struct ghes_arr *ghes_arr = data;
int rc;

if (hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR)
return 0;
- generic = (struct acpi_hest_generic *)hest_hdr;
- if (!generic->enabled)
+
+ if (!((struct acpi_hest_generic *)hest_hdr)->enabled)
return 0;
ghes_dev = platform_device_alloc("GHES", hest_hdr->source_id);
if (!ghes_dev)
return -ENOMEM;
- ghes_dev->dev.platform_data = generic;
+
+ rc = platform_device_add_data(ghes_dev, &hest_hdr, sizeof(void *));
+ if (rc)
+ goto err;
+
rc = platform_device_add(ghes_dev);
if (rc)
goto err;
--
1.7.1.1

2010-08-18 04:18:06

by Huang, Ying

Subject: Re: [PATCH 2/2][Patch-next -v2] ACPI, APEI, HEST Fix the unsuitable usage of platform_data.

On Wed, 2010-08-18 at 07:49 +0800, Jin Dongming wrote:
> platform_data in hest_parse_ghes() is used for saving the address of entry
> information of erst_tab. When the device is failed to be added, platform_data
> will be freed by platform_device_put(). But the value saved in platform_data
> should not be freed here. If it is done, it will make system panic.
>
> So I think platform_data should save the address of allocated memory
> which saves entry information of erst_tab.
>
> This patch fixed it and I confirmed it on x86_64 next-tree.
>
> Signed-off-by: Jin Dongming <[email protected]>
Acked-by: Huang Ying <[email protected]>

Best Regards,
Huang Ying