[PATCH] manual: describe unsupported SYS_clone{3} when used via syscall

[Yury Khrustalev]

Hi,

On Fri, Sep 12, 2025 at 05:25:00PM -0700, H. Peter Anvin wrote:
> On 2025-09-12 01:29, Yury Khrustalev wrote:
> > The syscall() function allows to make system calls directly, however
> > in the case of SYS_clone and SYS_clone3 the caller would have to take
> > care of extensive setup necessary for the internals of Glibc to work
> > correctly in the child threads which may make using syscall() with
> > these syscall numbers impractical.
> > 
> > ---
> > This need for this patch was discussed in
> > https://inbox.sourceware.org/libc-alpha/20250901095112.1672473-3-yury.khrustalev@arm.com/
> > 
> > base-commit: cae3c9e3a1
> 
> If you are going to make such an enumeration, you should add clone2
> (which some platforms have), vfork, sigreturn, and rt_sigreturn as well
> at a minimum.
> 
> All of them require very special handling of the stack.
> 
> 	-hpa

This is a very good point, thanks, I've changed it in v2:
https://patchwork.sourceware.org/project/glibc/list/?series=52093

Thanks,
Yury