On 29.08.2016 22:10, Konstantin Belousov wrote: > On Mon, Aug 29, 2016 at 09:16:29PM +0300, Andrey Chernov wrote: >> Previous text is documented everywhere and describing usual good >> practice, so it should remains in place, in that means r304928 should be >> reverted, because replace proper way of doing things with obsoleted >> feature description. >> >> What I suggest is not _replace_ old text with new, but _add_ new text as >> describing current and not recommended way, with the direct mention that >> this feature is obsoleted and not recommended for relay on it. >> > > diff --git a/lib/libc/sys/ptrace.2 b/lib/libc/sys/ptrace.2 > index 48802f4..d406efc 100644 > --- a/lib/libc/sys/ptrace.2 > +++ b/lib/libc/sys/ptrace.2 > @@ -2,7 +2,7 @@ > .\" $NetBSD: ptrace.2,v 1.2 1995/02/27 12:35:37 cgd Exp $ > .\" > .\" This file is in the public domain. > -.Dd August 28, 2016 > +.Dd August 29, 2016 > .Dt PTRACE 2 > .Os > .Sh NAME > @@ -900,19 +900,29 @@ argument is ignored. > .Pp > Additionally, other machine-specific requests can exist. > .Sh RETURN VALUES > +Most requests return 0 on success and \-1 on error. > Some requests can cause > .Fn ptrace > to return > \-1 > -as a non-error value; to disambiguate, > +as a non-error value, among them are > +.Dv PT_READ_I > +and > +.Dv PT_READ_D , > +which return the value read from the process memory on success. > +To disambiguate, > .Va errno > -is set to 0 in the libc wrapper for the > -.Fn ptrace > -system call and > +can be set to 0 before the call and checked afterwards. > +.Pp > +Current > .Fn ptrace > -callers can reliably check > +implementation always sets > +.Va errno > +to 0 before calling into kernel, both for historic reasons and for > +consistency with other operating systems. > +It is recommended to assign zero to > .Va errno > -for non-zero value afterwards. > +explicitely for future compatibility. > .Sh ERRORS > The > .Fn ptrace >
Ok. _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
