========================================================================= a.c ---------------------------------- void main (int argc, char **argv) { printf ("Salve, Munde! "); printf ("Vale! "); exit(0); } ========================================================================= dyldinfo -lazy_bind a ---------------------------------- lazy binding information (from lazy_bind part of dyld info): segment section address index dylib symbol __DATA __la_symbol_ptr 0x100001010 0x0000 libSystem _exit __DATA __la_symbol_ptr 0x100001018 0x000C libSystem _printf ========================================================================= otool -p _main -tV ---------------------------------- a: (__TEXT,__text) section _main: 0000000100000f10 pushq %rbp 0000000100000f11 movq %rsp, %rbp 0000000100000f14 subq $0x20, %rsp 0000000100000f18 leaq 0x61(%rip), %rax ## literal pool for: "Salve, Munde! " 0000000100000f1f movl %edi, -0x4(%rbp) 0000000100000f22 movq %rsi, -0x10(%rbp) 0000000100000f26 movq %rax, %rdi 0000000100000f29 movb $0x0, %al 0000000100000f2b callq 0x100000f54 ## symbol stub for: _printf <------ 0000000100000f30 leaq 0x58(%rip), %rdi ## literal pool for: "Vale! " 0000000100000f37 movl %eax, -0x14(%rbp) 0000000100000f3a movb $0x0, %al 0000000100000f3c callq 0x100000f54 ## symbol stub for: _printf <------ 0000000100000f41 movl $0x0, %edi 0000000100000f46 movl %eax, -0x18(%rbp) 0000000100000f49 callq 0x100000f4e ## symbol stub for: _exit <------ ========================================================================= otool -l -V a ---------------------------------- a: Load command 0 cmd LC_SEGMENT_64 cmdsize 72 segname __PAGEZERO vmaddr 0x0000000000000000 vmsize 0x0000000100000000 fileoff 0 filesize 0 maxprot --- initprot --- nsects 0 flags (none) Load command 1 cmd LC_SEGMENT_64 cmdsize 552 segname __TEXT vmaddr 0x0000000100000000 vmsize 0x0000000000001000 fileoff 0 filesize 4096 maxprot rwx initprot r-x nsects 6 flags (none) Section sectname __text segname __TEXT addr 0x0000000100000f10 size 0x000000000000003e offset 3856 align 2^4 (16) reloff 0 nreloc 0 type S_REGULAR attributes PURE_INSTRUCTIONS SOME_INSTRUCTIONS reserved1 0 reserved2 0 Section sectname __stubs segname __TEXT addr 0x0000000100000f4e <------ size 0x000000000000000c offset 3918 align 2^1 (2) reloff 0 nreloc 0 type S_SYMBOL_STUBS attributes PURE_INSTRUCTIONS SOME_INSTRUCTIONS reserved1 0 (index into indirect symbol table) reserved2 6 (size of stubs) Section sectname __stub_helper segname __TEXT addr 0x0000000100000f5c size 0x0000000000000024 offset 3932 align 2^2 (4) reloff 0 nreloc 0 type S_REGULAR attributes PURE_INSTRUCTIONS SOME_INSTRUCTIONS reserved1 0 reserved2 0 Section sectname __cstring segname __TEXT addr 0x0000000100000f80 size 0x0000000000000016 offset 3968 align 2^0 (1) reloff 0 nreloc 0 type S_CSTRING_LITERALS attributes (none) reserved1 0 reserved2 0 Section sectname __unwind_info segname __TEXT addr 0x0000000100000f96 size 0x0000000000000048 offset 3990 align 2^0 (1) reloff 0 nreloc 0 type S_REGULAR attributes (none) reserved1 0 reserved2 0 Section sectname __eh_frame segname __TEXT addr 0x0000000100000fe0 size 0x0000000000000018 offset 4064 align 2^3 (8) reloff 0 nreloc 0 type S_REGULAR attributes (none) reserved1 0 reserved2 0 Load command 2 cmd LC_SEGMENT_64 cmdsize 232 segname __DATA vmaddr 0x0000000100001000 vmsize 0x0000000000001000 fileoff 4096 filesize 4096 maxprot rwx initprot rw- nsects 2 flags (none) Section sectname __nl_symbol_ptr segname __DATA addr 0x0000000100001000 size 0x0000000000000010 offset 4096 align 2^3 (8) reloff 0 nreloc 0 type S_NON_LAZY_SYMBOL_POINTERS attributes (none) reserved1 2 (index into indirect symbol table) reserved2 0 Section sectname __la_symbol_ptr segname __DATA addr 0x0000000100001010 size 0x0000000000000010 offset 4112 align 2^3 (8) reloff 0 nreloc 0 type S_LAZY_SYMBOL_POINTERS attributes (none) reserved1 4 (index into indirect symbol table) reserved2 0 Load command 3 cmd LC_SEGMENT_64 cmdsize 72 segname __LINKEDIT vmaddr 0x0000000100002000 vmsize 0x0000000000001000 fileoff 8192 filesize 352 maxprot rwx initprot r-- nsects 0 flags (none) Load command 4 cmd LC_DYLD_INFO_ONLY cmdsize 48 rebase_off 8192 rebase_size 8 bind_off 8200 bind_size 24 weak_bind_off 0 weak_bind_size 0 lazy_bind_off 8224 lazy_bind_size 32 export_off 8256 export_size 48 Load command 5 cmd LC_SYMTAB cmdsize 24 symoff 8376 nsyms 5 stroff 8480 strsize 64 Load command 6 cmd LC_DYSYMTAB cmdsize 80 ilocalsym 0 nlocalsym 0 iextdefsym 0 nextdefsym 2 iundefsym 2 nundefsym 3 tocoff 0 ntoc 0 modtaboff 0 nmodtab 0 extrefsymoff 0 nextrefsyms 0 indirectsymoff 8456 nindirectsyms 6 extreloff 0 nextrel 0 locreloff 0 nlocrel 0 Load command 7 cmd LC_LOAD_DYLINKER cmdsize 32 name /usr/lib/dyld (offset 12) Load command 8 cmd LC_UUID cmdsize 24 uuid AAF0A21D-08BD-30FB-BB08-2A3352D9D4B9 Load command 9 cmd LC_VERSION_MIN_MACOSX cmdsize 16 version 10.9 sdk 10.9 Load command 10 cmd LC_SOURCE_VERSION cmdsize 16 version 0.0 Load command 11 cmd LC_MAIN cmdsize 24 entryoff 3856 stacksize 0 Load command 12 cmd LC_LOAD_DYLIB cmdsize 56 name /usr/lib/libSystem.B.dylib (offset 24) time stamp 2 Thu Jan 1 08:30:02 1970 current version 1197.1.1 compatibility version 1.0.0 Load command 13 cmd LC_FUNCTION_STARTS cmdsize 16 dataoff 8304 datasize 8 Load command 14 cmd LC_DATA_IN_CODE cmdsize 16 dataoff 8312 datasize 0 Load command 15 cmd LC_DYLIB_CODE_SIGN_DRS cmdsize 16 dataoff 8312 datasize 64 ========================================================================= nm a | grep "U " ---------------------------------- U _exit U _printf U dyld_stub_binder ========================================================================= nm a | wc -l ---------------------------------- 5 ========================================================================= x/2i 0x100000f4e ---------------------------------- 0x100000f4e <dyld_stub_exit>: jmpq *0xbc(%rip) # 0x100001010 <------ 0x100000f54 <dyld_stub_printf>: jmpq *0xbe(%rip) # 0x100001018 <------ ========================================================================= x/g 0x100001010 ---------------------------------- 0x100001010: 0x0000000100000f6c <------ ========================================================================= x/g 0x100001018 ---------------------------------- 0x100001018: 0x0000000100000f76 <------ ========================================================================= x/2i 0x0000000100000f6c <------ ---------------------------------- 0x100000f6c: pushq $0x0 0x100000f71: jmpq 0x100000f5c <------ ========================================================================= x/2i 0x0000000100000f76 <------ ---------------------------------- 0x100000f76: pushq $0xc 0x100000f7b: jmpq 0x100000f5c <------ ========================================================================= x/3i 0x100000f5c ---------------------------------- 0x100000f5c: lea 0xa5(%rip),%r11 # 0x100001008 0x100000f63: push %r11 0x100000f65: jmpq *0x95(%rip) # 0x100001000 <------ ========================================================================= x/2g 0x100001000 ---------------------------------- 0x100001000: 0x0000000000000000 0x0000000000000000 ========================================================================= b main ---------------------------------- r ---------------------------------- x/2g 0x100001000 ---------------------------------- 0x100001000: 0x00007fff8a2bc210 <------ 0x0000000000000000 ========================================================================= disass 0x00007fff8a2bc210 ---------------------------------- Dump of assembler code for function dyld_stub_binder: 0x00007fff8a2bc210 <dyld_stub_binder+0>: push %rbp 0x00007fff8a2bc211 <dyld_stub_binder+1>: mov %rsp,%rbp 0x00007fff8a2bc214 <dyld_stub_binder+4>: sub $0x140,%rsp 0x00007fff8a2bc21b <dyld_stub_binder+11>: mov %rdi,(%rsp) 0x00007fff8a2bc21f <dyld_stub_binder+15>: mov %rsi,0x8(%rsp) 0x00007fff8a2bc224 <dyld_stub_binder+20>: mov %rdx,0x10(%rsp) 0x00007fff8a2bc229 <dyld_stub_binder+25>: mov %rcx,0x18(%rsp) 0x00007fff8a2bc22e <dyld_stub_binder+30>: mov %r8,0x20(%rsp) 0x00007fff8a2bc233 <dyld_stub_binder+35>: mov %r9,0x28(%rsp) 0x00007fff8a2bc238 <dyld_stub_binder+40>: mov %rax,0x30(%rsp) End of assembler dump. ========================================================================= x/i dyld_stub_exit ---------------------------------- 0x100000f4e <dyld_stub_exit>: jmpq *0xbc(%rip) # 0x100001010 ========================================================================= x/i dyld_stub_printf ---------------------------------- 0x100000f54 <dyld_stub_printf>: jmpq *0xbe(%rip) # 0x100001018 ========================================================================= x/g 0x100001018 ---------------------------------- 0x100001018: 0x0000000100000f76 ========================================================================= x/2i 0x0000000100000f76 ---------------------------------- 0x100000f76: pushq $0xc 0x100000f7b: jmpq 0x100000f5c ========================================================================= b *0x0000000100000f2b b *0x0000000100000f3c ========================================================================= x/g 0x100001018 ---------------------------------- 0x100001018: 0x0000000100000f76 ========================================================================= x/2i 0x0000000100000f76 ---------------------------------- 0x100000f76: pushq $0xc 0x100000f7b: jmpq 0x100000f5c ========================================================================= x/g 0x100001018 ---------------------------------- 0x100001018: 0x00007fff883ba8a8 ========================================================================= x/2i 0x00007fff883ba8a8 ---------------------------------- 0x7fff883ba8a8 <printf>: push %rbp 0x7fff883ba8a9 <printf+1>: mov %rsp,%rbp =========================================================================