Gdy ltrace jest używany do śledzenia wywołań systemowych, widziałem, że fork () używa sys_clone () zamiast sys_fork (). Ale nie mogłem znaleźć źródła linuksa, w którym jest zdefiniowane.
Mój program to
#include<stdio.h>
main()
{
int pid,i=0,j=0;
pid=fork();
if(pid==0)
printf("\nI am child\n");
else
printf("\nI am parent\n");
}
I wyjście ltrace jest
SYS_brk(NULL) = 0x019d0000
SYS_access("/etc/ld.so.nohwcap", 00) = -2
SYS_mmap(0, 8192, 3, 34, 0xffffffff) = 0x7fe3cf84f000
SYS_access("/etc/ld.so.preload", 04) = -2
SYS_open("/etc/ld.so.cache", 0, 01) = 3
SYS_fstat(3, 0x7fff47007890) = 0
SYS_mmap(0, 103967, 1, 2, 3) = 0x7fe3cf835000
SYS_close(3) = 0
SYS_access("/etc/ld.so.nohwcap", 00) = -2
SYS_open("/lib/x86_64-linux-gnu/libc.so.6", 0, 00) = 3
SYS_read(3, "\177ELF\002\001\001", 832) = 832
SYS_fstat(3, 0x7fff470078e0) = 0
SYS_mmap(0, 0x389858, 5, 2050, 3) = 0x7fe3cf2a8000
SYS_mprotect(0x7fe3cf428000, 2097152, 0) = 0
SYS_mmap(0x7fe3cf628000, 20480, 3, 2066, 3) = 0x7fe3cf628000
SYS_mmap(0x7fe3cf62d000, 18520, 3, 50, 0xffffffff) = 0x7fe3cf62d000
SYS_close(3) = 0
SYS_mmap(0, 4096, 3, 34, 0xffffffff) = 0x7fe3cf834000
SYS_mmap(0, 4096, 3, 34, 0xffffffff) = 0x7fe3cf833000
SYS_mmap(0, 4096, 3, 34, 0xffffffff) = 0x7fe3cf832000
SYS_arch_prctl(4098, 0x7fe3cf833700, 0x7fe3cf832000, 34, 0xffffffff) = 0
SYS_mprotect(0x7fe3cf628000, 16384, 1) = 0
SYS_mprotect(0x7fe3cf851000, 4096, 1) = 0
SYS_munmap(0x7fe3cf835000, 103967) = 0
__libc_start_main(0x40054c, 1, 0x7fff47008298, 0x4005a0, 0x400590 <unfinished ...>
fork( <unfinished ...>
SYS_clone(0x1200011, 0, 0, 0x7fe3cf8339d0, 0) = 5967
<... fork resumed> ) = 5967
puts("\nI am parent" <unfinished ...>
SYS_fstat(1, 0x7fff47008060) = 0
SYS_mmap(0, 4096, 3, 34, 0xffffffff
) = 0x7fe3cf84e000
I am child
SYS_write(1, "\n", 1
) = 1
SYS_write(1, "I am parent\n", 12) = -512
--- SIGCHLD (Child exited) ---
SYS_write(1, "I am parent\n", 12I am parent
) = 12
<... puts resumed> ) = 13
SYS_exit_group(13 <no return ...>
+++ exited (status 13) +++