Re: reading elf section data

[Gery <zaphod001@gmail.com>]

Glynn Clements wrote:
> Gery wrote:
>
>   
>> i put some structure with gcc attribute to special section named ".my_sec"
>> The structure is like
>> struct abc {
>> char *a;
>> char *b;
>> };
>> and global variable is
>> struct abc klm = { "this is 1st string", "this is 2nd string" };
>>     
>
> Like this:
>
> struct abc klm __attribute__ ((section (".my_sec"))) = { "this is 1st string", "this is 2nd string" };
>
> ?
>
>   
>> Which utility can show me just the data of that section?
>>     
>
> 	$ objdump -j .my_sec -d foo.o
>
> 	foo.o:     file format elf32-i386
> 	
> 	Disassembly of section .my_sec:
> 	
> 	00000000 <klm>:
> 	   0:	00 00 00 00 13 00 00 00                             ........
>
> Bear in mind that the structure only contains the pointers, not the
> strings themselves. String literals used as values are stored in the
> .rodata section. If you want them elsewhere, you'll have to store them
> in named variables, e.g.:
>
> 	static char s1[] __attribute__ ((section (".my_sec"))) = "this is 1st string";
> 	static char s2[] __attribute__ ((section (".my_sec"))) = "this is 2nd string";
> 	struct abc klm __attribute__ ((section (".my_sec"))) = { s1, s2 };
>
> 	$ objdump -j .my_sec -d foo.o
>
> 	foo.o:     file format elf32-i386
> 	
> 	Disassembly of section .my_sec:
> 	
> 	00000000 <s1>:
> 	   0:	74 68 69 73 20 69 73 20 31 73 74 20 73 74 72 69     this is 1st stri
> 	  10:	6e 67 00                                            ng.
> 	
> 	00000013 <s2>:
> 	  13:	74 68 69 73 20 69 73 20 32 6e 64 20 73 74 72 69     this is 2nd stri
> 	  23:	6e 67 00 00 00                                      ng...
> 	
> 	00000028 <klm>:
> 	  28:	00 00 00 00 13 00 00 00                             ........
>
>   
Thank you very much :))