ref: ae9a74441cba3160943ad18bf500781143bff096
dir: /lib/sys/syscall+linux-x64.s/
.globl sys$syscall sys$syscall: /* hack: We load 6 args regardless of how many we actually have. This may load junk values, but if the syscall doesn't use them, it's going to be harmless. */ movq %rdi,%rax /* 8(%rsp): hidden type arg */ movq 16(%rsp),%rdi movq 24(%rsp),%rsi movq 32(%rsp),%rdx movq 40(%rsp),%r10 movq 48(%rsp),%r8 movq 56(%rsp),%r9 syscall ret /* clone(flags, stack, ptid, tls, ctid, regs) */ .globl sys$fnclone sys$fnclone: pushq %r15 /* %rsp is modified by clone(), so it's saved here */ movq 16(%rsp),%r15 /* %rdi: flags, %rsi: stack, %rdx: ptid, %rcx: tls, %r8: ctid, %r9: regs */ movq $56,%rax /* syscall num */ movq %rcx,%r10 /* tls */ 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