Re: [PATCH v2 04/20] vmcore: allocate buffer for ELF headers on page-size alignment

HATAYAMA Daisuke
2013-03-06T09:15:06Z

From: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Subject: Re: [PATCH v2 04/20] vmcore: allocate buffer for ELF headers on page-size alignment
Date: Wed, 6 Mar 2013 14:57:50 +0800

> 于 2013年03月02日 16:36, HATAYAMA Daisuke 写道:
>> Allocate buffer for ELF headers on page-size aligned boudary to
>> satisfy mmap() requirement. For this, __get_free_pages() is used
>> instead of kmalloc().
>>
>> Also, later patch will decrease actually used buffer size for ELF
>> headers, so it's necessary to keep original buffer size and actually
>> used buffer size separately. elfcorebuf_sz_orig keeps the original one
>> and elfcorebuf_sz the actually used one.
>>
>> Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
>> ---
>>
>> fs/proc/vmcore.c | 30 +++++++++++++++++++++---------
>> 1 files changed, 21 insertions(+), 9 deletions(-)
>>

....

>> @@ -665,26 +671,31 @@ static int __init parse_crash_elf32_headers(void)
>>
>> /* Read in all elf headers. */
>> elfcorebuf_sz = ehdr.e_phoff + ehdr.e_phnum * sizeof(Elf32_Phdr);
>> - elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
>> + elfcorebuf_sz_orig = elfcorebuf_sz;
>> + elfcorebuf = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
>> + get_order(elfcorebuf_sz));
>
> Why not elfcorebuf_sz_orig here?
>

Thanks. I'll fix this.

Thanks.
HATAYAMA, Daisuke