On Sun, Apr 7, 2013 at 9:03 PM, Mike Frysinger <vapier@xxxxxxxxxx> wrote: > On Sunday 07 April 2013 06:15:18 Michael Kerrisk (man-pages) wrote: >> On Fri, Apr 5, 2013 at 6:01 PM, Peter Schiffer wrote: >> > it looks like the clone(2) man page is describing glibc implementation >> > and not the system call. So I guess it should be moved to the section 3 >> > and a new man page for clone(2) syscall should be created in section 2. >> > >> > The clone(2) syscall is defined like this: >> > >> > SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, >> > int __user *, parent_tidptr, >> > int __user *, child_tidptr, >> > int, tls_val) >> > >> > (I'm sorry, but I don't have a patch this time.) >> >> The general tendency is to document all system calls in section 2, and >> if there are some differences caused by wrapper functions, then they >> are noted on the page. >> >> I admint that clone(2) is an unusual case. The signature given at the >> top of the page is for the wrapper (and later the difference to the >> syscall raw interface are described). However, the details are >> primarily about the underlying kernel interface, so I'm inclined to >> leave the page where it is. > > i think his point is that the syscall doesn't take a func pointer. it is > userspace (the C lib) that takes care of making the clone syscall and then > calling the function. the man page doesn't mention this anywhere that i see. Yes, I've tried to claify this. > the notes section does refer to this as being a "system call" instead of a > "system call wrapper" when discussing ia64. And I've also tried to clarify that. > also, the quoted syscall signature isn't the whole story. there's actually > more variants: > #ifdef __ARCH_WANT_SYS_CLONE > #ifdef CONFIG_CLONE_BACKWARDS > SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, > int __user *, parent_tidptr, > int, tls_val, > int __user *, child_tidptr) > #elif defined(CONFIG_CLONE_BACKWARDS2) > SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags, > int __user *, parent_tidptr, > int __user *, child_tidptr, > int, tls_val) > #else > SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, > int __user *, parent_tidptr, > int __user *, child_tidptr, > int, tls_val) > ... I've worked in some of the above detail; see the Git copy of the page. > these arches don't define __ARCH_WANT_SYS_CLONE: > blackfin ia64 m68k sparc I'm not sure of the significance of the above; can you explain? > and i gave up enumerating all the other edge cases :) Okay. Cheers, Michael -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
