Yeah, you're right. The syscall does ask for a size_t. It now looks correct. The whole length-after-the-string part is edited out, and the value is indeed place

Yeah, you're right. The syscall does ask for a size_t. It now looks correct. The whole length-after-the-string part is edited out, and the value is indeed placed as immediate (as the syscall wants). Now the binary ends with "hello, world\n" and 14 is inserted directly (b9 a4 80 04 08, ba 0d 00 00 00).