(2010/08/17 10:39), Huang Ying wrote:
> On Tue, 2010-08-17 at 08:58 +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.
>
> Good catch. Thanks.
>
>> 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 <jin.dongming@xxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/acpi/apei/ghes.c | 2 +-
>> drivers/acpi/apei/hest.c | 19 ++++++++++++++-----
>> 2 files changed, 15 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
>> index 385a605..b35c622 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..5a65e2a 100644
>> --- a/drivers/acpi/apei/hest.c
>> +++ b/drivers/acpi/apei/hest.c
>> @@ -137,20 +137,29 @@ 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;
>> + void **platform_data;
>> 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)
>> +
>> + platform_data = kmalloc(sizeof(void *), GFP_KERNEL);
>> + if (!platform_data)
>> + return -ENOMEM;
>> +
>> + *platform_data = hest_hdr;
>> + if (!((struct acpi_hest_generic *)*platform_data)->enabled)
>> return 0;
>> +
>> ghes_dev = platform_device_alloc("GHES", hest_hdr->source_id);
>> - if (!ghes_dev)
>> + if (!ghes_dev) {
>> + kfree(platform_data);
>> return -ENOMEM;
>> - ghes_dev->dev.platform_data = generic;
>> + }
>> +
>> + ghes_dev->dev.platform_data = platform_data;
>> rc = platform_device_add(ghes_dev);
>> if (rc)
>> goto err;
>
> Why not use platform_device_add_data?
Here what should be done is to transport the pointer of hest_hdr to platform_data,
so I think that it could be done successfully by allocating 8byte of memory.
If the platform_device_add_data() is used, the more memory will be allocated.
So I think this method is better than using platform_device_add_data().
>
> Best Regards,
> Huang Ying
>
>
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