ref: 10a209f1937d161e1ff5409deb06253facff73a6
dir: /lib/thread/clone+linux-x64.s/
.globl thread$clone thread$clone: pushq %r15 movq 16(%rsp),%r15 /* clone(flags, stack, ptid, tls, ctid, regs) */ movq $56,%rax /* syscall num */ /* %rdi: flags */ /* %rsi: stack */ /* %rdx: ptid */ movq %rcx,%r10 /* tls */ /* %r8: ctid */ /* %r9: regs */ syscall /* fn() */ testl %eax,%eax jnz parent call *%r15 /* exit(0) */ movq $60, %rax /* exit */ movq $0, %rdi /* arg: 0 */ syscall parent: popq %r15 ret