yes, GOT is mentioned here: http://www.itee.uq.edu.au/~emmerik/elf.html But as I objdump the "vmlinux" I cannot find any ".got", but I can find in binaries like /bin/ls. why? objdump -h /boot/vmlinux /boot/vmlinux: file format elf32-i386 Sections: Idx Name Size VMA LMA File off Algn 0 .text.head 0000039d c1000000 01000000 00001000 2**2 CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE 1 .text 00255e90 c1001000 01001000 00002000 2**12 CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE 2 __ex_table 00000ed8 c1256e90 01256e90 00257e90 2**4 CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA 3 .rodata 00108da5 c1258000 01258000 00259000 2**7 CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA 4 .eh_frame 00000eac c1360da8 01360da8 00361da8 2**2 CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA 5 __bug_table 00003d5c c1361c58 01361c58 00362c58 2**0 CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA etc etc etc.....no ".got" listed. but in vdso32.lds I can find the following definition: SECTIONS { . = 0 + SIZEOF_HEADERS; .hash : { *(.hash) } :text .gnu.hash : { *(.gnu.hash) } .dynsym : { *(.dynsym) } .dynstr : { *(.dynstr) } .gnu.version : { *(.gnu.version) } .gnu.version_d : { *(.gnu.version_d) } .gnu.version_r : { *(.gnu.version_r) } .note : { *(.note.*) } :text :note .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr .eh_frame : { KEEP (*(.eh_frame)) } :text .dynamic : { *(.dynamic) } :text :dynamic .rodata : { *(.rodata*) } :text .data : { *(.data*) *(.sdata*) *(.got.plt) *(.got) *(.gnu.linkonce.d.*) *(.bss*) *(.dynbss*) *(.gnu.linkonce.b.*) } .altinstructions : { *(.altinstructions) } .altinstr_replacement : { *(.altinstr_replacement) } so does it mean that ".got" etc got clumped together into the ".data" section? On Sun, Oct 26, 2008 at 2:47 AM, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote: > Hi > > On Sat, Oct 25, 2008 at 10:02 PM, loody <miloody@xxxxxxxxx> wrote: >> Dear all: >> I find there is a section in vmlinux.lds defined as below: >> _got_start = .; >> .got : { *(.got) } >> _got_end = .; >> .got.plt : { *(.got.plt) } >> .data : { *(.data) } >> _edata = .; >> >> As far as I know, this file is used to generate vmlinux.lds and ld >> will use it to combine compressed kernel, proper head.s, by different >> cpu, and misc.c to zImage. >> >> so I think the .got sections will be defined in obj codes in this >> folder, compressed. >> But I cannot get any information about got, could someone tell me >> where it is and what it is used for? > > In short, GOT (global offset table) holds the address of external > functions (functions on external libraries). You can read more about > it in my article here: > http://www.linuxforums.org/misc/understanding_elf_using_readelf_and_objdump.html > > regards, > > Mulyadi. > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > Please read the FAQ at http://kernelnewbies.org/FAQ > > -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
