[PATCH] mips: vmcore: forced convert 'hdr' in elf_check_arch()

yjin yanjiang.jin at windriver.com
Sun Sep 20 19:23:29 PDT 2015


It seems the last mail has been blocked, resend it.

On 2015年09月21日 10:16, yjin wrote:
> The new version patch only modifies mips/elf.h, so add Ralf Baechle 
> and cc linux-mips at linux-mips.org.
> This is a V2 patch, attach the V1 patch for reference.
>
> Thanks!
> Yanjiang
>
> On 2015年09月18日 15:42, yanjiang.jin at windriver.com wrote:
>> From: Yanjiang Jin <yanjiang.jin at windriver.com>
>>
>> elf_check_arch() will be called both in parse_crash_elf64_headers()
>> and parse_crash_elf32_headers(). But in these two functions, the type of
>> the parameter ehdr is different: Elf32_Ehdr and Elf64_Ehdr.
>>
>> Function parse_crash_elf_headers() reads e_ident[EI_CLASS] then 
>> decides to
>> call parse_crash_elf64_headers() or parse_crash_elf32_headers().
>> This happens in run time, not compile time. So compiler will report
>> the below warning:
>>
>> In file included from include/linux/elf.h:4:0,
>>                   from fs/proc/vmcore.c:13:
>> fs/proc/vmcore.c: In function 'parse_crash_elf32_headers':
>> arch/mips/include/asm/elf.h:258:23: warning: initializatio
>> n from incompatible pointer type
>>    struct elfhdr *__h = (hdr);     \
>>                         ^
>> fs/proc/vmcore.c:1071:4: note: in expansion of macro 'elf_
>> check_arch'
>>     !elf_check_arch(&ehdr) ||
>>      ^
>>
>> Signed-off-by: Yanjiang Jin <yanjiang.jin at windriver.com>
>> ---
>>   arch/mips/include/asm/elf.h | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
>> index f19e890..ece490d 100644
>> --- a/arch/mips/include/asm/elf.h
>> +++ b/arch/mips/include/asm/elf.h
>> @@ -224,7 +224,7 @@ struct mips_elf_abiflags_v0 {
>>   #define elf_check_arch(hdr)                        \
>>   ({                                    \
>>       int __res = 1;                            \
>> -    struct elfhdr *__h = (hdr);                    \
>> +    struct elfhdr *__h = (struct elfhdr *)(hdr);            \
>>                                       \
>>       if (__h->e_machine != EM_MIPS)                    \
>>           __res = 0;                        \
>> @@ -255,7 +255,7 @@ struct mips_elf_abiflags_v0 {
>>   #define elf_check_arch(hdr)                        \
>>   ({                                    \
>>       int __res = 1;                            \
>> -    struct elfhdr *__h = (hdr);                    \
>> +    struct elfhdr *__h = (struct elfhdr *)(hdr);            \
>>                                       \
>>       if (__h->e_machine != EM_MIPS)                    \
>>           __res = 0;                        \
>




More information about the kexec mailing list