Re: syscall_cp

[Rich Felker <dalias@libc.org>]

On Fri, Jan 29, 2016 at 06:03:54PM -0500, Max Ruttenberg wrote:
> and syscall_ret ??

It's a shortcut to avoid duplicating the errno update code in every
syscall wrapper. Instead they all just tail call to __syscall_ret
which returns -1 and sets errno if the return value was an error code,
and otherwise just passes through the return value.

BTW could you please reply inline-with/below quoted text on the list
rather than top-posting? Top-posting makes it hard to follow the flow
of conversation.

Rich


> On Fri, Jan 29, 2016 at 5:50 PM, Josiah Worcester <josiahw@gmail.com> wrote:
> 
> > syscall_cp does largely the same thing as syscall. However, it also checks
> > for a current cancellation request, and exports some symbols (before and
> > after the syscall call) which are used in the thread cancellation
> > implementation. It makes it so the cancellation handler can know whether or
> > not the cancellation request happened during or after a syscall. (if
> > during, it needs to cancel the thread, if after, then it needs to continue
> > executing until the next cancellation point.)
> >
> > On Fri, Jan 29, 2016 at 2:41 PM Max Ruttenberg <
> > mruttenberg@emutechnology.com> wrote:
> >
> >> What is syscall_cp and what is it supposed to do that syscall isn't?
> >>
> >>
> >> --
> >> Max Ruttenberg,
> >> Member of the Technical Staff
> >> Emu *Technology*
> >> 1400 E Angela Blvd, Unit 101
> >> South Bend, IN 46617
> >>
> >
> 
> 
> -- 
> Max Ruttenberg,
> Member of the Technical Staff
> Emu *Technology*
> 1400 E Angela Blvd, Unit 101
> South Bend, IN 46617