Why is my nasm program killing itself?
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From: Evenbit on 15 Apr 2008 04:09 On Apr 13, 12:12 pm, Frank Kotler <fbkot...(a)verizon.net> wrote: > > (We *can* do dynamic > linking! Have you looked at Stephen Pelc's example at all?) Interesting paper! NEXT STEP: Use this method to access the GObject system and you'll be creating GUI apps without a linker! :) http://en.wikipedia.org/wiki/GObject http://library.gnome.org/devel/gobject/unstable/ Nathan.
From: Herbert Kleebauer on 15 Apr 2008 05:31 Frank Kotler wrote: > Herbert Kleebauer wrote: > >> (We *can* do dynamic > >> linking! Have you looked at Stephen Pelc's example at all?) Searched in the my saved documentation. Yes, it was his article I read. > > I have read one article about doing it manually by using a trivial > > hash table, but I think I would prefer to modify the assembler > > so it would generate a real hash table. > > Okay. What's wrong with the "trivial" one? I'll have to look at It's like your assembler doesn't for some reason assemble the instruction "inc edx". I don't have any problem to use "db 0x42" instead, the generated binary is the same (this is like including the elf header with "db" statements in the assembler source). But I wouldn't like to replace any "inc edx" by the sequence: xchg eax,edx inc eax xchg eax,edx just because my assembler doesn't support the "inc edx" instruction. I think then it is better to modify the assembler so it will support the "inc edx" instruction and the same is true for the hash table for dynamic linking. I understand that this is a problem for the wide spread NASM. But in my case it doesn't matter whether in include the additional code in the source code of the assembly program or in the C source of the assembler. I also don't need macro support, because when ever I need something like a macro, I can implement it in the assembler instead in the assembly source code. As Betov included the assembly source in the binary, I (logically) include the in C written assembler source in the assembly source a therefore have the full power of the C compiler available. > Here's one more way to fix a broken executable. More complicated than it > needs to be - I was inspired by Almas! :) I don't know if it's even > "right". Works on the few I've tried it on... I'll have to boot to 12.0 > and make a few more. Or, hmmm, what if I copied over the missing > libraries... > > Best, > Frank > > ; fetches byte 48h, rounds up to a multiple of 4 > ; and stuffs it into byte 58h I don't think this will solve the problem, there are still 3 bytes missing (from the "align 4") in the output file and therefore the data segment starts at an odd file address. Try it with a program which prints an initialized variable. The correct calculation would be: even 4 @=(@+4095)/4096*4096+(@@\4096) data_offset=@@ data_addr: But it does: @=(@+3)/4*4 @@1=(@@+3)/4*4 @=(@+4095)/4096*4096+(@@1\4096) data_offset=@@ data_addr:
From: Herbert Kleebauer on 15 Apr 2008 09:33 Frank Kotler wrote: > Okay. What's wrong with the "trivial" one? I'll have to look at > Stephen's code again Maybe this is useful: Here a complete disassembly of the following C program I made two years ago. ------------------------------------------------------------------------------ char uninit_global_char, init_global_char=1; int uninit_global_int, init_global_int=2; main() {char uninit_local_char, init_local_char=3; int uninit_local_int, init_local_int=4; uninit_local_char = init_global_char; uninit_local_int = init_global_int; uninit_global_char= init_local_char; uninit_global_int = init_local_int; printf("hello world %d %d %d %d %d %d %d %d\n", uninit_global_char, init_global_char, uninit_global_int, init_global_int, uninit_local_char, init_local_char, uninit_local_int, init_local_int); } ------------------------------------------------------------------------------ nop=$90 seg32 @=$08048000 ;============================================================================= ;=== Start of Segment 2 === ;============================================================================= SEGM02_type=1 ; PT_LOAD Loadable segment SEGM02_flags=5 ; PF_R + PF_X (1: execute 2: write 4:read) SEGM02_align=4096 even 4 @=(@+SEGM02_align-1)/SEGM02_align*SEGM02_align+(@@\SEGM02_align) SEGM02_offset=@@ SEGM02_vaddr: SEGM02_paddr: ;***************************************************************************** ;*** Start of ELF HEADER *** ;***************************************************************************** EI_NIDENT=16 ; e_ident[EI_NIDENT] dc.b $7f,"ELF" ; EI_MAG[0:3] File identification dc.b 1 ; EI_CLASS ELFCASS32 32-bit objects dc.b 1 ; EI_DATA ELFDATA2LSB 2's comp. little endian dc.b 1 ; EI_VERSION EV_CURRENT blk.b EI_NIDENT-@@,0 ; EI_PAD dc.w 2 ; e_type ET_EXEC Executable file dc.w 3 ; e_machine EM_386 Intel386 dc.l 1 ; e_version EV_CURRENT Current version dc.l start ; e_entry Virtal address of starting point dc.l e_phoff ; e_phoff Offset to program header table dc.l e_shoff ; e_shoff Offset to section header table dc.l 0 ; e_flags Processor-specific flags dc.w e_ehsize ; e_ehsize Size of ELF header dc.w e_phentsize ; e_phentsize Size of a program header table entry dc.w e_phnum ; e_phnum Number of entries in program header table dc.w e_shentsize ; e_shentsize Size of a section header table entry dc.w e_shnum ; e_shnum Number of entries in section header table dc.w e_shstrndx ; e_shstrndx Table index for section name string table e_ehsize=@@ ;***************************************************************************** ;*** End of ELF HEADER *** ;***************************************************************************** ;***************************************************************************** ;*** Start of Program header table *** ;***************************************************************************** e_phoff=@@ ;============================================================================= ;=== Start of Segment 0 === ;============================================================================= SEGM00_type=6 ; PT_PHDR Program header table SEGM00_flags=5 ; PF_R + PF_X (1: execute 2: write 4:read) SEGM00_align=4 even SEGM00_align ; oder "even 4" ?????????? SEGM00_offset=@@ SEGM00_vaddr: SEGM00_paddr: ; Segment 0 PT_PHDR Program header table dc.l SEGM00_type ; p_type dc.l SEGM00_offset ; p_offset dc.l SEGM00_vaddr ; p_vaddr dc.l SEGM00_paddr ; p_paddr dc.l SEGM00_filez ; p_filez dc.l SEGM00_memsz ; p_memsz dc.l SEGM00_flags ; P_flags dc.l SEGM00_align ; p_align e_phentsize=@@-e_phoff ; Segment 1 PT_INTERP Path name to interpreter dc.l SEGM01_type ; p_type dc.l SEGM01_offset ; p_offset dc.l SEGM01_vaddr ; p_vaddr dc.l SEGM01_paddr ; p_paddr dc.l SEGM01_filez ; p_filez dc.l SEGM01_memsz ; p_memsz dc.l SEGM01_flags ; P_flags dc.l SEGM01_align ; p_align ; Segment 2 ; PT_LOAD Loadable segment dc.l SEGM02_type ; p_type dc.l SEGM02_offset ; p_offset dc.l SEGM02_vaddr ; p_vaddr dc.l SEGM02_paddr ; p_paddr dc.l SEGM02_filez ; p_filez dc.l SEGM02_memsz ; p_memsz dc.l SEGM02_flags ; P_flags dc.l SEGM02_align ; p_align ; Segment 3 ; PT_LOAD Loadable segment dc.l SEGM03_type ; p_type dc.l SEGM03_offset ; p_offset dc.l SEGM03_vaddr ; p_vaddr dc.l SEGM03_paddr ; p_paddr dc.l SEGM03_filez ; p_filez dc.l SEGM03_memsz ; p_memsz dc.l SEGM03_flags ; P_flags dc.l SEGM03_align ; p_align ; Segment 4 ; PT_DYNAMIC Dynamic linking dc.l SEGM04_type ; p_type dc.l SEGM04_offset ; p_offset dc.l SEGM04_vaddr ; p_vaddr dc.l SEGM04_paddr ; p_paddr dc.l SEGM04_filez ; p_filez dc.l SEGM04_memsz ; p_memsz dc.l SEGM04_flags ; P_flags dc.l SEGM04_align ; p_align ; Segment 5 ; PT_NOTE Auxilary information dc.l SEGM05_type ; p_type dc.l SEGM05_offset ; p_offset dc.l SEGM05_vaddr ; p_vaddr dc.l SEGM05_paddr ; p_paddr dc.l SEGM05_filez ; p_filez dc.l SEGM05_memsz ; p_memsz dc.l SEGM05_flags ; P_flags dc.l SEGM05_align ; p_align ; Segment 6 ; ??????Stack????? dc.l $6474e551 ; p_type ; ?????? dc.l $00000000 ; p_offset dc.l $00000000 ; p_vaddr dc.l $00000000 ; p_paddr dc.l $00000000 ; p_filez dc.l $00000000 ; p_memsz dc.l $00000006 ; P_flags dc.l $00000004 ; p_align SEGM00_filez=@@-SEGM00_offset SEGM00_memsz=@-SEGM00_vaddr ;============================================================================= ;=== End of Segment 0 === ;============================================================================= e_phnum=(@@-e_phoff)/e_phentsize ;***************************************************************************** ;*** End of Program header table *** ;***************************************************************************** ;============================================================================= ;=== Start of Segment 1 === ;============================================================================= SEGM01_type=3 ; PT_INTERP Path name to interpreter SEGM01_flags=4 ; PF_R (1: execute 2: write 4:read) SEGM01_align=1 even SEGM01_align ; oder "even 4" ?????????? SEGM01_offset=@@ SEGM01_vaddr: SEGM01_paddr: ;----------------------------------------------------------------------------- ;--- Start of Section 1 --- ;----------------------------------------------------------------------------- SECT01_name=sect_name02 ; ".interp" SECT01_type=1 ; SHT_PROGBITS SECT01_flags=2 ; SHF_ALLOC SECT01_link=0 SECT01_info=0 SECT01_addralign=1 SECT01_entsize=0 even SECT01_addralign SECT01_offset=@@ SECT01_addr: dc.b "/lib/ld-linux.so.2",0 SECT01_size=@@-SECT01_offset ;----------------------------------------------------------------------------- ;--- End of Section 1 --- ;----------------------------------------------------------------------------- SEGM01_filez=@@-SEGM01_offset SEGM01_memsz=@-SEGM01_vaddr ;============================================================================= ;=== End of Segment 1 === ;============================================================================= ;============================================================================= ;=== Start of Segment 5 === ;============================================================================= SEGM05_type=4 ; PT_NOTE Auxilary information SEGM05_flags=4 ; PF_R (1: execute 2: write 4:read) SEGM05_align=4 even SEGM05_align ; oder "even 4" ?????????? SEGM05_offset=@@ SEGM05_vaddr: SEGM05_paddr: ;----------------------------------------------------------------------------- ;--- Start of Section 2 --- ;----------------------------------------------------------------------------- SECT02_name=sect_name03 ; ".note.ABI-tag" SECT02_type=7 ; SHT_NOTE SECT02_flags=2 ; SHF_ALLOC SECT02_link=0 SECT02_info=0 SECT02_addralign=4 SECT02_entsize=0 even SECT02_addralign SECT02_offset=@@ SECT02_addr: dc.l _name_l ; namesz dc.l _desc_l ; descsz dc.l 1 ; type _name: dc.b "GNU",0 _name_l=@-_name _desc: dc.l 0,2,2,0 _desc_l=@-_desc SECT02_size=@@-SECT02_offset ;----------------------------------------------------------------------------- ;--- End of Section 2 --- ;----------------------------------------------------------------------------- SEGM05_filez=@@-SEGM05_offset SEGM05_memsz=@-SEGM05_vaddr ;============================================================================= ;=== End of Segment 5 === ;============================================================================= ;----------------------------------------------------------------------------- ;--- Start of Section 3 --- ;----------------------------------------------------------------------------- SECT03_name=sect_name04 ; ".hash" SECT03_type=5 ; SHT_HASH SECT03_flags=2 ; SHF_ALLOC SECT03_link=4 ; this hash is for symbol tabel in SECT04 SECT03_info=0 SECT03_addralign=4 SECT03_entsize=4 even SECT03_addralign SECT03_offset=@@ SECT03_addr: DT_HASH: dc.l 3 ; nbucket dc.l 6 ; nchain dc.l 5 ; bucket[0] dc.l 1 ; bucket[1] dc.l 3 ; bucket[2] dc.l 0 ; chain[0] dc.l 0 ; chain[1] dc.l 0 ; chain[2] dc.l 2 ; chain[3] dc.l 0 ; chain[4] dc.l 4 ; chain[5] SECT03_size=@@-SECT03_offset ;----------------------------------------------------------------------------- ;--- End of Section 3 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 4 --- ;----------------------------------------------------------------------------- SECT04_name=sect_name05 ; ".dynsym" SECT04_type=11 ; SHT_DYNSYM SECT04_flags=2 ; SHF_ALLOC SECT04_link=5 ; associated string table ->SECT05 SECT04_info=1 ; 1 + 0 : no local symbols????? SECT04_addralign=4 SECT04_entsize=16 even SECT04_addralign SECT04_offset=@@ SECT04_addr: DT_SYMTAB: dc.l 0 ; st_name dc.l 0 ; st_value dc.l 0 ; st_size dc.b 0 ; st_info dc.b 0 ; st_other dc.w 0 ; st_shndx DT_SYMENT=@-DT_SYMTAB sym_tab_libc_start_main=(@-DT_SYMTAB)/DT_SYMENT dc.l dyn_name06 ; st_name "__libc_start_main" dc.l 0 ; st_value dc.l $fa ; st_size dc.b $12 ; st_info STB_GLOBAL + STT_FUNC dc.b 0 ; st_other dc.w 0 ; st_shndx sym_tab_printf=(@-DT_SYMTAB)/DT_SYMENT dc.l dyn_name04 ; st_name "printf" dc.l 0 ; st_value dc.l $39 ; st_size dc.b $12 ; st_info STB_GLOBAL + STT_FUNC dc.b 0 ; st_other dc.w 0 ; st_shndx dc.l dyn_name05 ; st_name "_IO_stdin_used" dc.l IO_stdin_used ; st_value dc.l 4 ; st_size dc.b $11 ; st_info STB_GLOBAL + STT_OBJECT dc.b 0 ; st_other dc.w 14 ; st_shndx defined in section 14 dc.l dyn_name01 ; st_name "_Jv_RegisterClasses" dc.l 0 ; st_value dc.l 0 ; st_size dc.b $20 ; st_info STB_WEAK + STT_NOTYPE dc.b 0 ; st_other dc.w 0 ; st_shndx sym_tab_gmon_start=(@-DT_SYMTAB)/DT_SYMENT dc.l dyn_name02 ; st_name __gmon_start__" dc.l 0 ; st_value dc.l 0 ; st_size dc.b $20 ; st_info STB_WEAK + STT_NOTYPE dc.b 0 ; st_other dc.w 0 ; st_shndx SECT04_size=@@-SECT04_offset ;----------------------------------------------------------------------------- ;--- End of Section 4 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 5 --- ;----------------------------------------------------------------------------- SECT05_name=sect_name06 ; ".dynstr" SECT05_type=3 ; SHT_STRTAB SECT05_flags=2 ; SHF_ALLOC SECT05_link=0 SECT05_info=0 SECT05_addralign=1 SECT05_entsize=0 even SECT05_addralign SECT05_offset=@@ SECT05_addr: DT_STRTAB: @1=@ dyn_name00=@-@1 dc.b 0 dyn_name01=@-@1 dc.b "_Jv_RegisterClasses",0 dyn_name02=@-@1 dc.b "__gmon_start__",0 DT_NEEDED=@-DT_STRTAB dyn_name03=@-@1 dc.b "libc.so.6",0 dyn_name04=@-@1 dc.b "printf",0 dyn_name05=@-@1 dc.b "_IO_stdin_used",0 dyn_name06=@-@1 dc.b "__libc_start_main",0 dyn_name07=@-@1 dc.b "GLIBC_2.0",0 DT_STRSZ=@-DT_STRTAB SECT05_size=@@-SECT05_offset ;----------------------------------------------------------------------------- ;--- End of Section 5 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 6 --- ;----------------------------------------------------------------------------- SECT06_name=sect_name07 ; ".gnu.version" SECT06_type=$6fffffff ; ???????? SECT06_flags=2 ; SHF_ALLOC SECT06_link=4 ; ?????????? SECT06_info=0 SECT06_addralign=2 SECT06_entsize=2 even SECT06_addralign SECT06_offset=@@ SECT06_addr: DT_Y: dc.l $00020000, $00010002, 0 SECT06_size=@@-SECT06_offset ;----------------------------------------------------------------------------- ;--- End of Section 6 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 7 --- ;----------------------------------------------------------------------------- SECT07_name=sect_name08 ; ".gnu.version.r" SECT07_type=$6ffffffe ; ????????? SECT07_flags=2 ; SHF_ALLOC SECT07_link=5 ; ????????? SECT07_info=1 SECT07_addralign=4 SECT07_entsize=0 even SECT07_addralign SECT07_offset=@@ SECT07_addr: DT_X: dc.l $00010001, $00000024, $00000010, 0 dc.l $0d696910, $00020000, $00000056, 0 SECT07_size=@@-SECT07_offset ;----------------------------------------------------------------------------- ;--- End of Section 7 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 8 --- ;----------------------------------------------------------------------------- SECT08_name=sect_name09 ; ".rel.dyn" SECT08_type=9 ; SHT_REL SECT08_flags=2 ; SHF_ALLOC SECT08_link=4 ; associated symbole tabel -> SECT04 SECT08_info=0 ; relocation applies to no section (SECT0) ??? SECT08_addralign=4 SECT08_entsize=8 even SECT08_addralign SECT08_offset=@@ SECT08_addr: DT_REL: dc.l gmon_start, (sym_tab_gmon_start<<8) + 6 ; R_386_GLOB_DAT DT_RELENT=@-DT_REL DT_RELSZ=@-DT_REL SECT08_size=@@-SECT08_offset ;----------------------------------------------------------------------------- ;--- End of Section 8 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 9 --- ;----------------------------------------------------------------------------- SECT09_name=sect_name10 ; ".rel.plt" SECT09_type=9 ; SHT_REL SECT09_flags=2 ; SHF_ALLOC SECT09_link=4 ; associated symbole tabel -> SECT04 SECT09_info=11 ; relocation applies to SECT11 SECT09_addralign=4 SECT09_entsize=8 even SECT09_addralign SECT09_offset=@@ SECT09_addr: DT_JUMPREL: @1=@ rel_tab_libc_start_main=@-@1 dc.l got_libc_start_main,(sym_tab_libc_start_main<<8)+7 ;R_386_JMP_SLOT rel_tab_printf=@-@1 dc.l got_printf, (sym_tab_printf<<8)+7 ; R_386_JMP_SLOT DT_PLTRELSZ=@-DT_JUMPREL SECT09_size=@@-SECT09_offset ;----------------------------------------------------------------------------- ;--- End of Section 9 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 10 --- ;----------------------------------------------------------------------------- SECT10_name=sect_name12 ; ".init" SECT10_type=1 ; SHT_PROGBITS SECT10_flags=6 ; SHF_ALLOC + SHF_EXECINSTR SECT10_link=0 SECT10_info=0 SECT10_addralign=4 SECT10_entsize=0 even SECT10_addralign SECT10_offset=@@ SECT10_addr: DT_INIT: init: move.l r4,-(sp) move.l r7,r4 subq.l #8,r7 bsr.l init1 bsr.l init2 bsr.l init3 unlk.l r4 rts.l SECT10_size=@@-SECT10_offset ;----------------------------------------------------------------------------- ;--- End of Section 10 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 11 --- ;----------------------------------------------------------------------------- SECT11_name=sect_name11 ; ".plt" SECT11_type=1 ; SHT_PROGBITS SECT11_flags=6 ; SHF_ALLOC + SHF_EXECINSTR SECT11_link=0 SECT11_info=0 SECT11_addralign=4 SECT11_entsize=4 even SECT11_addralign SECT11_offset=@@ SECT11_addr: bind: move.l got1,-(sp) ; identifying information for dynamic likner jmp.l (got2) ; call dynamic linker even 16,0 libc_start_main: jmp.l (got_libc_start_main) bind_libc_start_main: move.l #rel_tab_libc_start_main,-(sp) br.l bind printf: jmp.l (got_printf) bind_printf: move.l #rel_tab_printf,-(sp) ; offset in relocation table br.l bind ; call dynamic linker for late binding SECT11_size=@@-SECT11_offset ;----------------------------------------------------------------------------- ;--- End of Section 11 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 12 --- ;----------------------------------------------------------------------------- SECT12_name=sect_name13 ; ".text" SECT12_type=1 ; SHT_PROGBITS SECT12_flags=6 ; SHF_ALLOC + SHF_EXECINSTR SECT12_link=0 SECT12_info=0 SECT12_addralign=16 SECT12_entsize=0 even SECT12_addralign SECT12_offset=@@ SECT12_addr: start: eor.l r4,r4 move.l (sp)+,r5 move.l r7,r2 andq.l #-16,r7 move.l r0,-(sp) move.l r7,-(sp) move.l r1,-(sp) move.l #start1,-(sp) move.l #start2,-(sp) move.l r2,-(sp) move.l r5,-(sp) move.l #main,-(sp) bsr.l libc_start_main dc.b $f4 ; halt (bug in windela!) even 4,nop init1: move.l r4,-(sp) move.l r7,r4 move.l r3,-(sp) bsr.l _20 _20: move.l (sp)+,r3 add.l #$00001353,r3 move.l r0,-(sp) move.l 20(r3),r0 tst.l r0,r0 beq.b _10 jsr.l (r0) _10: move.l -4.b(r4){s7},r3 unlk.l r4 rts.l even 16,nop cleanup1: move.l r4,-(sp) move.l r7,r4 subq.l #8,r7 cmp.b #0,var1 beq.b _30 br.b _10 br.b _20 even 16,nop _20: addq.l #4,r0 move.l r0,var2 jsr.l (r1) _30: move.l var2,r0 move.l (r0),r1 tst.l r1,r1 bne.b _20 move.b #1,var1 _10: unlk.l r4 rts.l move.l r5,r5 ; 2byte nop -> even 16 init2: move.l r4,-(sp) move.l r7,r4 subq.l #8,r7 move.l var3,r0 tst.l r0,r0 beq.b _10 move.l #0,r0 tst.l r0,r0 beq.b _10 subq.l #12,r7 move.l #var3,-(sp) bsr.l 0 addq.l #16,r7 nop dc.b $8d,$b4,$26,$00,$00,$00,$00 ; lea.l 0(r5),r5 ; (7byte nop) ->even 16 _10: unlk.l r4 rts.l ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; uninit_local_char = -1 init_local_char = -2 uninit_local_int = -8 init_local_int = -12 even 4,nop main: move.l r4,-(sp) move.l r7,r4 subq.l #24,r7 andq.l #$f0,r7 move.l #0,r0 addq.l #15,r0 addq.l #15,r0 lsr.l #4,r0 lsl.l #4,r0 sub.l r0,r7 move.b #3,init_local_char.b(r4){s7} move.l #4,init_local_int.b(r4){s7} move.b init_global_char,r0 move.b r0,uninit_local_char.b(r4){s7} move.l init_global_int,r0 move.l r0,uninit_local_int.b(r4){s7} move.b init_local_char.b(r4){s7},r0 move.b r0,unint_global_char move.l init_local_int.b(r4){s7},r0 move.l r0,uninit_global_int subq.l #12,r7 move.l init_local_int.b(r4){s7},-(sp) move.l uninit_local_int.b(r4){s7},-(sp) movs.bl init_local_char.b(r4){s7},r0 move.l r0,-(sp) movs.bl uninit_local_char.b(r4){s7},r0 move.l r0,-(sp) move.l init_global_int,-(sp) move.l uninit_global_int,-(sp) movs.bl init_global_char,r0 move.l r0,-(sp) movs.bl unint_global_char,r0 move.l r0,-(sp) move.l #printf_format_string,-(sp) bsr.l printf addq.l #48,r7 unlk.l r4 rts.l ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; even 16,nop start2: move.l r4,-(sp) move.l r7,r4 move.l r6,-(sp) move.l r5,-(sp) eor.l r5,r5 move.l r3,-(sp) subq.l #12,r7 bsr.l start3 add.l #$1220,r3 bsr.l init lea.l -$f4(r3),r1 lea.l -$f4(r3),r0 sub.l r0,r1 asr.l #2,r1 cmp.l r1,r5 bcc.b _20 move.l r1,r6 dc.b $8d,$b4,$26,$00,$00,$00,$00 ;lea.l 0(r5),r5 7byte nop dc.b $8d,$bc,$27,$00,$00,$00,$00 ;lea.l 0(r6),r6 7byte nop _10: jsr.l (-$f4(r3,r5*4)) inc.l r5 cmp.l r6,r5 bcs.b _10 _20: addq.l #12,r7 move.l (sp)+,r3 move.l (sp)+,r5 move.l (sp)+,r6 move.l (sp)+,r4 rts.l lea.l 0(r5),r5 ; 6byte nop lea.l 0(r6),r6 ; 6byte nop start1: move.l r4,-(sp) move.l r7,r4 subq.l #8,r7 move.l r3,(r7){s7} bsr.l start3 add.l #$000011c2,r3 move.l r5,4.b(r7){s7} lea.l $ffffff0c(r3),r0 lea.l $ffffff0c(r3),r1 sub.l r1,r0 asr.l #2,r0 tst.l r0,r0 lea.l -1.b(r0),r5 bne.b _10 _20: bsr.l cleanup move.l (r7){s7},r3 move.l 4.b(r7){s7},r5 move.l r4,r7 move.l (sp)+,r4 rts.l _10: jsr.l ($ffffff0c(r3,r5*4)) move.l r5,r0 dec.l r5 tst.l r0,r0 bne.b _10 br.b _20 start3: move.l (r7){s7},r3 rts.l even 16,nop init3: move.l r4,-(sp) move.l r7,r4 move.l r3,-(sp) move.l r1,-(sp) move.l #var4,r3 move.l var4,r0 br.b _20 br.b _10 even 16,nop _10: subq.l #4,r3 jsr.l (r0) move.l (r3),r0 _20: cmpq.l #-1,r0 bne.b _10 move.l (sp)+,r0 move.l (sp)+,r3 move.l (sp)+,r4 rts.l SECT12_size=@@-SECT12_offset ;----------------------------------------------------------------------------- ;--- End of Section 12 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 13 --- ;----------------------------------------------------------------------------- SECT13_name=sect_name14 ; ".fini" SECT13_type=1 ; SHT_PROGBITS SECT13_flags=6 ; SHF_ALLOC + SHF_EXECINSTR SECT13_link=0 SECT13_info=0 SECT13_addralign=4 SECT13_entsize=0 even SECT13_addralign SECT13_offset=@@ SECT13_addr: DT_FINI: cleanup:move.l r4,-(sp) move.l r7,r4 move.l r3,-(sp) bsr.l _10 _10: move.l (sp)+,r3 add.l #$1137,r3 move.l r1,-(sp) bsr.l cleanup1 move.l -4.b(r4){s7},r3 unlk.l r4 rts.l SECT13_size=@@-SECT13_offset ;----------------------------------------------------------------------------- ;--- End of Section 13 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 14 --- ;----------------------------------------------------------------------------- SECT14_name=sect_name15 ; ".rodata" SECT14_type=1 ; SHT_PROGBITS SECT14_flags=2 ; SHF_ALLOC SECT14_link=0 SECT14_info=0 SECT14_addralign=4 SECT14_entsize=0 even SECT14_addralign SECT14_offset=@@ SECT14_addr: dc.l $00000003 IO_stdin_used: dc.l $00020001 printf_format_string: dc.b "hello world %d %d %d %d %d %d %d %d",10,0 SECT14_size=@@-SECT14_offset ;----------------------------------------------------------------------------- ;--- End of Section 14 --- ;----------------------------------------------------------------------------- SEGM02_filez=@@-SEGM02_offset SEGM02_memsz=@-SEGM02_vaddr ;============================================================================= ;=== End of Segment 2 === ;============================================================================= ;============================================================================= ;=== Start of Segment 3 === ;============================================================================= SEGM03_type=1 ; PT_LOAD Loadable segment SEGM03_flags=6 ; PF_R + PF_W (1: execute 2: write 4:read) SEGM03_align=4096 even 4 @=(@+SEGM03_align-1)/SEGM03_align*SEGM03_align+(@@\SEGM03_align) SEGM03_offset=@@ SEGM03_vaddr: SEGM03_paddr: ;----------------------------------------------------------------------------- ;--- Start of Section 15 --- ;----------------------------------------------------------------------------- SECT15_name=sect_name16 ; ".data" SECT15_type=1 ; SHT_PROGBITS SECT15_flags=3 ; SHF_ALLOC + SHF_WRITE SECT15_link=0 SECT15_info=0 SECT15_addralign=4 SECT15_entsize=0 even SECT15_addralign SECT15_offset=@@ SECT15_addr: dc.l 0 dc.l 0 var2: dc.l var5 init_global_char: dc.l 1 init_global_int: dc.l 2 SECT15_size=@@-SECT15_offset ;----------------------------------------------------------------------------- ;--- End of Section 15 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 16 --- ;----------------------------------------------------------------------------- SECT16_name=sect_name17 ; ".eh_frame" SECT16_type=1 ; SHT_PROGBITS SECT16_flags=2 ; SHF_ALLOC SECT16_link=0 SECT16_info=0 SECT16_addralign=4 SECT16_entsize=0 even SECT16_addralign SECT16_offset=@@ SECT16_addr: dc.l 0 SECT16_size=@@-SECT16_offset ;----------------------------------------------------------------------------- ;--- End of Section 16 --- ;----------------------------------------------------------------------------- ;============================================================================= ;=== Start of Segment 4 === ;============================================================================= SEGM04_type=2 ; PT_DYNAMIC Dynamic linking SEGM04_flags=6 ; PF_R + PF_W (1: execute 2: write 4:read) SEGM04_align=4 even SEGM04_align ; oder "even 4" ?????????? SEGM04_offset=@@ SEGM04_vaddr: SEGM04_paddr: ;----------------------------------------------------------------------------- ;--- Start of Section 17 --- ;----------------------------------------------------------------------------- SECT17_name=sect_name18 ; ".dynamic" SECT17_type=6 ; SHT_DYNAMIC SECT17_flags=3 ; SHF_ALLOC + SHF_EXECINSTR SECT17_link=5 ; string tabel -> SECT05 SECT17_info=0 SECT17_addralign=4 SECT17_entsize=8 even SECT17_addralign SECT17_offset=@@ SECT17_addr: DYNAMIC: dc.l 1, DT_NEEDED ; DT_NEEDED dc.l 12, DT_INIT ; DT_INIT dc.l 13, DT_FINI ; DT_FINI dc.l 4, DT_HASH ; DT_HASH dc.l 5, DT_STRTAB ; DT_STRTAB dc.l 6, DT_SYMTAB ; DT_SYMTAB dc.l 10, DT_STRSZ ; DT_STRSZ dc.l 11, DT_SYMENT ; DT_SYMENT dc.l 21, 0 ; DT_DEBUG dc.l 3, DT_PLTGOT ; DT_PLTGOT dc.l 2, DT_PLTRELSZ ; DT_PLTRELSZ dc.l 20, 17 ; DT_PLTREL -> DT_REL dc.l 23, DT_JUMPREL ; DT_JUMPREL dc.l 17, DT_REL ; DT_REL dc.l 18, DT_RELSZ ; DT_RELSZ dc.l 19, DT_RELENT ; DT_RELENT dc.l $6ffffffe, DT_X ; ??? dc.l $6fffffff, $00000001 ; ??? dc.l $6ffffff0, DT_Y ; ??? dc.l 0, $00000000 ; DT_NULL dc.l 0, $00000000 ; DT_NULL dc.l 0, $00000000 ; DT_NULL dc.l 0, $00000000 ; DT_NULL dc.l 0, $00000000 ; DT_NULL dc.l 0, $00000000 ; DT_NULL SECT17_size=@@-SECT17_offset ;----------------------------------------------------------------------------- ;--- End of Section 17 --- ;----------------------------------------------------------------------------- SEGM04_filez=@@-SEGM04_offset SEGM04_memsz=@-SEGM04_vaddr ;============================================================================= ;=== End of Segment 4 === ;============================================================================= ;----------------------------------------------------------------------------- ;--- Start of Section 18 --- ;----------------------------------------------------------------------------- SECT18_name=sect_name19 ; ".stors" SECT18_type=1 ; SHT_PROGBITS SECT18_flags=3 ; SHF_ALLOC + SHF_WRITE SECT18_link=0 SECT18_info=0 SECT18_addralign=4 SECT18_entsize=0 even SECT18_addralign SECT18_offset=@@ SECT18_addr: var4: dc.l -1 dc.l 0 SECT18_size=@@-SECT18_offset ;----------------------------------------------------------------------------- ;--- End of Section 18 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 19 --- ;----------------------------------------------------------------------------- SECT19_name=sect_name20 ; ".dtors" SECT19_type=1 ; SHT_PROGBITS SECT19_flags=3 ; SHF_ALLOC + SHF_WRITE SECT19_link=0 SECT19_info=0 SECT19_addralign=4 SECT19_entsize=0 even SECT19_addralign SECT19_offset=@@ SECT19_addr: dc.l -1 var5: dc.l 0 SECT19_size=@@-SECT19_offset ;----------------------------------------------------------------------------- ;--- End of Section 19 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 20 --- ;----------------------------------------------------------------------------- SECT20_name=sect_name21 ; ".jcr" SECT20_type=1 ; SHT_PROGBITS SECT20_flags=3 ; SHF_ALLOC + SHF_WRITE SECT20_link=0 SECT20_info=0 SECT20_addralign=4 SECT20_entsize=0 even SECT20_addralign SECT20_offset=@@ SECT20_addr: var3: dc.l 0 SECT20_size=@@-SECT20_offset ;----------------------------------------------------------------------------- ;--- End of Section 20 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 21 --- ;----------------------------------------------------------------------------- SECT21_name=sect_name22 ; ".got" SECT21_type=1 ; SHT_PROGBITS SECT21_flags=3 ; SHF_ALLOC + SHF_WRITE SECT21_link=0 SECT21_info=0 SECT21_addralign=4 SECT21_entsize=4 even SECT21_addralign SECT21_offset=@@ SECT21_addr: DT_PLTGOT: dc.l DYNAMIC ; reserved for address of dynamic structure got1: dc.l 0 ; reserved (inserted by loader, info for late bind.) got2: dc.l 0 ; reserved (inserted by loader, ptr to dyn. linker) got_libc_start_main: dc.l bind_libc_start_main got_printf: dc.l bind_printf ; replaced by address of printf (by loader or ; by bind_printf if late binding) gmon_start: dc.l 0 SECT21_size=@@-SECT21_offset ;----------------------------------------------------------------------------- ;--- End of Section 21 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 22 --- ;----------------------------------------------------------------------------- SECT22_name=sect_name23 ; ".bss" SECT22_type=8 ; SHT_NOBITS SECT22_flags=3 ; SHF_ALLOC + SHF_WRITE SECT22_link=0 SECT22_info=0 SECT22_addralign=4 SECT22_entsize=0 even SECT22_addralign SECT22_offset=@@ SECT22_addr: var1: blk.b 1 blk.b 3 ; even 4 unint_global_char: blk.l 1 uninit_global_int: blk.l 1 ; SECT22_size=@@-SECT22_offset ; should be correct SECT22_size=12 ; because of SHT_NOBITS also ok ;----------------------------------------------------------------------------- ;--- End of Section 22 --- ;----------------------------------------------------------------------------- SEGM03_filez=@@-SEGM03_offset SEGM03_memsz=@-SEGM03_vaddr ;============================================================================= ;=== End of Segment 3 === ;============================================================================= ;----------------------------------------------------------------------------- ;--- Start of Section 23 --- ;----------------------------------------------------------------------------- SECT23_name=sect_name24 ; ".comment" SECT23_type=1 ; SHT_PROGBITS SECT23_flags=0 SECT23_link=0 SECT23_info=0 SECT23_addralign=1 SECT23_entsize=0 even SECT23_addralign SECT23_offset=@@ SECT23_addr=0 dc.b 0,"GCC: (GNU) 3.3.5 (Debian 1:3.3.5-1)",0 dc.b 0,"GCC: (GNU) 3.3.5 (Debian 1:3.3.5-1)",0 dc.b 0,"GCC: (GNU) 3.4.4 20041128 (prerelease) (Debian 3.4.3-3)",0 dc.b 0,"GCC: (GNU) 3.4.4 20041128 (prerelease) (Debian 3.4.3-3)",0 dc.b 0,"GCC: (GNU) 3.3.5 (Debian 1:3.3.5-1)",0 dc.b 0,"GCC: (GNU) 3.4.4 20041128 (prerelease) (Debian 3.4.3-3)",0 dc.b 0,"GCC: (GNU) 3.3.5 (Debian 1:3.3.5-1)",0 SECT23_size=@@-SECT23_offset ;----------------------------------------------------------------------------- ;--- End of Section 23 --- ;----------------------------------------------------------------------------- ;----------------------------------------------------------------------------- ;--- Start of Section 24 --- ;----------------------------------------------------------------------------- SECT24_name=sect_name01 ; ".shstrtab" SECT24_type=3 ; SHT_STRTAB SECT24_flags=0 SECT24_link=0 SECT24_info=0 SECT24_addralign=1 SECT24_entsize=0 even SECT24_addralign SECT24_offset=@@ SECT24_addr=0 e_shstrndx=24 @1=@ sect_name00=@-@1 dc.b 0 sect_name01=@-@1 dc.b ".shstrtab",0 sect_name02=@-@1 dc.b ".interp",0 sect_name03=@-@1 dc.b ".note.ABI-tag",0 sect_name04=@-@1 dc.b ".hash",0 sect_name05=@-@1 dc.b ".dynsym",0 sect_name06=@-@1 dc.b ".dynstr",0 sect_name07=@-@1 dc.b ".gnu.version",0 sect_name08=@-@1 dc.b ".gnu.version_r",0 sect_name09=@-@1 dc.b ".rel.dyn",0 sect_name10=@-@1 dc.b ".rel" sect_name11=@-@1 dc.b ".plt",0 sect_name12=@-@1 dc.b ".init",0 sect_name13=@-@1 dc.b ".text",0 sect_name14=@-@1 dc.b ".fini",0 sect_name15=@-@1 dc.b ".rodata",0 sect_name16=@-@1 dc.b ".data",0 sect_name17=@-@1 dc.b ".eh_frame",0 sect_name18=@-@1 dc.b ".dynamic",0 sect_name19=@-@1 dc.b ".ctors",0 sect_name20=@-@1 dc.b ".dtors",0 sect_name21=@-@1 dc.b ".jcr",0 sect_name22=@-@1 dc.b ".got",0 sect_name23=@-@1 dc.b ".bss",0 sect_name24=@-@1 dc.b ".comment",0 SECT24_size=@@-SECT24_offset ;----------------------------------------------------------------------------- ;--- End of Section 24 --- ;----------------------------------------------------------------------------- ;***************************************************************************** ;*** Start of Section header table *** ;***************************************************************************** even 4 e_shoff=@@ ; section 0 dc.l 0 ; sh_name dc.l 0 ; sh_type dc.l 0 ; sh_flags dc.l 0 ; sh_addr dc.l 0 ; sh_offset dc.l 0 ; sh_size dc.l 0 ; sh_link dc.l 0 ; sh_info dc.l 0 ; sh_addralign dc.l 0 ; sh_entsize e_shentsize=@@-e_shoff ; section 1 dc.l SECT01_name ; sh_name dc.l SECT01_type ; sh_type dc.l SECT01_flags ; sh_flags dc.l SECT01_addr ; sh_addr dc.l SECT01_offset ; sh_offset dc.l SECT01_size ; sh_size dc.l SECT01_link ; sh_link dc.l SECT01_info ; sh_info dc.l SECT01_addralign; sh_addralign dc.l SECT01_entsize ; sh_entsize ; section 2 dc.l SECT02_name ; sh_name dc.l SECT02_type ; sh_type dc.l SECT02_flags ; sh_flags dc.l SECT02_addr ; sh_addr dc.l SECT02_offset ; sh_offset dc.l SECT02_size ; sh_size dc.l SECT02_link ; sh_link dc.l SECT02_info ; sh_info dc.l SECT02_addralign; sh_addralign dc.l SECT02_entsize ; sh_entsize ; section 3 dc.l SECT03_name ; sh_name dc.l SECT03_type ; sh_type dc.l SECT03_flags ; sh_flags dc.l SECT03_addr ; sh_addr dc.l SECT03_offset ; sh_offset dc.l SECT03_size ; sh_size dc.l SECT03_link ; sh_link dc.l SECT03_info ; sh_info dc.l SECT03_addralign; sh_addralign dc.l SECT03_entsize ; sh_entsize ; section 4 dc.l SECT04_name ; sh_name dc.l SECT04_type ; sh_type dc.l SECT04_flags ; sh_flags dc.l SECT04_addr ; sh_addr dc.l SECT04_offset ; sh_offset dc.l SECT04_size ; sh_size dc.l SECT04_link ; sh_link dc.l SECT04_info ; sh_info dc.l SECT04_addralign; sh_addralign dc.l SECT04_entsize ; sh_entsize ; section 5 dc.l SECT05_name ; sh_name dc.l SECT05_type ; sh_type dc.l SECT05_flags ; sh_flags dc.l SECT05_addr ; sh_addr dc.l SECT05_offset ; sh_offset dc.l SECT05_size ; sh_size dc.l SECT05_link ; sh_link dc.l SECT05_info ; sh_info dc.l SECT05_addralign; sh_addralign dc.l SECT05_entsize ; sh_entsize ; section 6 dc.l SECT06_name ; sh_name dc.l SECT06_type ; sh_type dc.l SECT06_flags ; sh_flags dc.l SECT06_addr ; sh_addr dc.l SECT06_offset ; sh_offset dc.l SECT06_size ; sh_size dc.l SECT06_link ; sh_link dc.l SECT06_info ; sh_info dc.l SECT06_addralign; sh_addralign dc.l SECT06_entsize ; sh_entsize ; section 7 dc.l SECT07_name ; sh_name dc.l SECT07_type ; sh_type dc.l SECT07_flags ; sh_flags dc.l SECT07_addr ; sh_addr dc.l SECT07_offset ; sh_offset dc.l SECT07_size ; sh_size dc.l SECT07_link ; sh_link dc.l SECT07_info ; sh_info dc.l SECT07_addralign; sh_addralign dc.l SECT07_entsize ; sh_entsize ; section 8 dc.l SECT08_name ; sh_name dc.l SECT08_type ; sh_type dc.l SECT08_flags ; sh_flags dc.l SECT08_addr ; sh_addr dc.l SECT08_offset ; sh_offset dc.l SECT08_size ; sh_size dc.l SECT08_link ; sh_link dc.l SECT08_info ; sh_info dc.l SECT08_addralign; sh_addralign dc.l SECT08_entsize ; sh_entsize ; section 9 dc.l SECT09_name ; sh_name dc.l SECT09_type ; sh_type dc.l SECT09_flags ; sh_flags dc.l SECT09_addr ; sh_addr dc.l SECT09_offset ; sh_offset dc.l SECT09_size ; sh_size dc.l SECT09_link ; sh_link dc.l SECT09_info ; sh_info dc.l SECT09_addralign; sh_addralign dc.l SECT09_entsize ; sh_entsize ; section 10 dc.l SECT10_name ; sh_name dc.l SECT10_type ; sh_type dc.l SECT10_flags ; sh_flags dc.l SECT10_addr ; sh_addr dc.l SECT10_offset ; sh_offset dc.l SECT10_size ; sh_size dc.l SECT10_link ; sh_link dc.l SECT10_info ; sh_info dc.l SECT10_addralign; sh_addralign dc.l SECT10_entsize ; sh_entsize ; section 11 dc.l SECT11_name ; sh_name dc.l SECT11_type ; sh_type dc.l SECT11_flags ; sh_flags dc.l SECT11_addr ; sh_addr dc.l SECT11_offset ; sh_offset dc.l SECT11_size ; sh_size dc.l SECT11_link ; sh_link dc.l SECT11_info ; sh_info dc.l SECT11_addralign; sh_addralign dc.l SECT11_entsize ; sh_entsize ; section 12 dc.l SECT12_name ; sh_name dc.l SECT12_type ; sh_type dc.l SECT12_flags ; sh_flags dc.l SECT12_addr ; sh_addr dc.l SECT12_offset ; sh_offset dc.l SECT12_size ; sh_size dc.l SECT12_link ; sh_link dc.l SECT12_info ; sh_info dc.l SECT12_addralign; sh_addralign dc.l SECT12_entsize ; sh_entsize ; section 13 dc.l SECT13_name ; sh_name dc.l SECT13_type ; sh_type dc.l SECT13_flags ; sh_flags dc.l SECT13_addr ; sh_addr dc.l SECT13_offset ; sh_offset dc.l SECT13_size ; sh_size dc.l SECT13_link ; sh_link dc.l SECT13_info ; sh_info dc.l SECT13_addralign; sh_addralign dc.l SECT13_entsize ; sh_entsize ; section 14 dc.l SECT14_name ; sh_name dc.l SECT14_type ; sh_type dc.l SECT14_flags ; sh_flags dc.l SECT14_addr ; sh_addr dc.l SECT14_offset ; sh_offset dc.l SECT14_size ; sh_size dc.l SECT14_link ; sh_link dc.l SECT14_info ; sh_info dc.l SECT14_addralign; sh_addralign dc.l SECT14_entsize ; sh_entsize ; section 15 dc.l SECT15_name ; sh_name dc.l SECT15_type ; sh_type dc.l SECT15_flags ; sh_flags dc.l SECT15_addr ; sh_addr dc.l SECT15_offset ; sh_offset dc.l SECT15_size ; sh_size dc.l SECT15_link ; sh_link dc.l SECT15_info ; sh_info dc.l SECT15_addralign; sh_addralign dc.l SECT15_entsize ; sh_entsize ; section 16 dc.l SECT16_name ; sh_name dc.l SECT16_type ; sh_type dc.l SECT16_flags ; sh_flags dc.l SECT16_addr ; sh_addr dc.l SECT16_offset ; sh_offset dc.l SECT16_size ; sh_size dc.l SECT16_link ; sh_link dc.l SECT16_info ; sh_info dc.l SECT16_addralign; sh_addralign dc.l SECT16_entsize ; sh_entsize ; section 17 dc.l SECT17_name ; sh_name dc.l SECT17_type ; sh_type dc.l SECT17_flags ; sh_flags dc.l SECT17_addr ; sh_addr dc.l SECT17_offset ; sh_offset dc.l SECT17_size ; sh_size dc.l SECT17_link ; sh_link dc.l SECT17_info ; sh_info dc.l SECT17_addralign; sh_addralign dc.l SECT17_entsize ; sh_entsize ; section 18 dc.l SECT18_name ; sh_name dc.l SECT18_type ; sh_type dc.l SECT18_flags ; sh_flags dc.l SECT18_addr ; sh_addr dc.l SECT18_offset ; sh_offset dc.l SECT18_size ; sh_size dc.l SECT18_link ; sh_link dc.l SECT18_info ; sh_info dc.l SECT18_addralign; sh_addralign dc.l SECT18_entsize ; sh_entsize ; section 19 dc.l SECT19_name ; sh_name dc.l SECT19_type ; sh_type dc.l SECT19_flags ; sh_flags dc.l SECT19_addr ; sh_addr dc.l SECT19_offset ; sh_offset dc.l SECT19_size ; sh_size dc.l SECT19_link ; sh_link dc.l SECT19_info ; sh_info dc.l SECT19_addralign; sh_addralign dc.l SECT19_entsize ; sh_entsize ; section 20 dc.l SECT20_name ; sh_name dc.l SECT20_type ; sh_type dc.l SECT20_flags ; sh_flags dc.l SECT20_addr ; sh_addr dc.l SECT20_offset ; sh_offset dc.l SECT20_size ; sh_size dc.l SECT20_link ; sh_link dc.l SECT20_info ; sh_info dc.l SECT20_addralign; sh_addralign dc.l SECT20_entsize ; sh_entsize ; section 21 dc.l SECT21_name ; sh_name dc.l SECT21_type ; sh_type dc.l SECT21_flags ; sh_flags dc.l SECT21_addr ; sh_addr dc.l SECT21_offset ; sh_offset dc.l SECT21_size ; sh_size dc.l SECT21_link ; sh_link dc.l SECT21_info ; sh_info dc.l SECT21_addralign; sh_addralign dc.l SECT21_entsize ; sh_entsize ; section 22 dc.l SECT22_name ; sh_name dc.l SECT22_type ; sh_type dc.l SECT22_flags ; sh_flags dc.l SECT22_addr ; sh_addr dc.l SECT22_offset ; sh_offset dc.l SECT22_size ; sh_size dc.l SECT22_link ; sh_link dc.l SECT22_info ; sh_info dc.l SECT22_addralign; sh_addralign dc.l SECT22_entsize ; sh_entsize ; section 23 dc.l SECT23_name ; sh_name dc.l SECT23_type ; sh_type dc.l SECT23_flags ; sh_flags dc.l SECT23_addr ; sh_addr dc.l SECT23_offset ; sh_offset dc.l SECT23_size ; sh_size dc.l SECT23_link ; sh_link dc.l SECT23_info ; sh_info dc.l SECT23_addralign; sh_addralign dc.l SECT23_entsize ; sh_entsize ; section 24 dc.l SECT24_name ; sh_name dc.l SECT24_type ; sh_type dc.l SECT24_flags ; sh_flags dc.l SECT24_addr ; sh_addr dc.l SECT24_offset ; sh_offset dc.l SECT24_size ; sh_size dc.l SECT24_link ; sh_link dc.l SECT24_info ; sh_info dc.l SECT24_addralign; sh_addralign dc.l SECT24_entsize ; sh_entsize e_shnum=(@@-e_shoff)/e_shentsize ;***************************************************************************** ;*** End of Section header table *** ;*****************************************************************************
From: Chuck Crayne on 15 Apr 2008 20:25 On Tue, 15 Apr 2008 21:49:35 GMT Frank Kotler <fbkotler(a)verizon.net> wrote: > So now I can build "suicidal executables" any time I want - > and so can you! And so can we all. Using this new toy, I can see why having a .data section makes a difference. Apparently assuming that NOBODY would be crazy enough to have a .bss section without also having a .data section, the "bad" linker builds a single program header entry which includes both the .data and .bss sections (in that order) so, as long as the .data section is correctly aligned, there is no need to align the .bss section. Then, along comes some crazy assembly language programmer . . . -- Chuck http://www.pacificsites.com/~ccrayne/charles.html
From: Frank Kotler on 15 Apr 2008 23:42
Chuck Crayne wrote: > On Tue, 15 Apr 2008 21:49:35 GMT > Frank Kotler <fbkotler(a)verizon.net> wrote: > >> So now I can build "suicidal executables" any time I want - >> and so can you! > > And so can we all. Using this new toy, I can see why having a .data > section makes a difference. Apparently assuming that NOBODY would be > crazy enough to have a .bss section without also having a .data > section, the "bad" linker builds a single program header entry which > includes both the .data and .bss sections (in that order) so, as long as > the .data section is correctly aligned, there is no need to align > the .bss section. Then, along comes some crazy assembly language > programmer . . . Yeah... This issue confused me. I didn't expect the Gas example (sys_exit with .bss) to get killed. When we were looking at the "last section must be writeable" issue, I observed that Gas users wouldn't ever see it, because Gas added a .data section, whether we asked for it or not. Still does, in the object file, and with an older ld (2.13), in the executable, too. But newer ld versions (2.17.50.bad.day and 2.18) *don't* have a .data section in the executable, and so get killed. Incidentally, I tried Fasm, and its object files, linked with the "bad" version, get killed, too. Come back, Ivan! It was only a bad linker! (if he'd posted the failing executable, we could have pinned it on the linker a lot sooner, probably) Best, Frank |