Date: Mon, 29 Aug 2016 14:14:41 -0500 From: Benjamin Kaduk <bjkfbsd@gmail.com> To: Konstantin Belousov <kostikbel@gmail.com> Cc: Andrey Chernov <ache@freebsd.org>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>, John Baldwin <jhb@freebsd.org> Subject: Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys Message-ID: <CAJ5_RoBiwiYN9k8ans8MgabcepRmpu_LDC7aFrLvGoQ3tU2BBw@mail.gmail.com> In-Reply-To: <20160829191035.GV83214@kib.kiev.ua> References: <201608272303.u7RN3N0D078505@repo.freebsd.org> <1595604.93PBdSz0kX@ralph.baldwin.cx> <20160829065813.GP83214@kib.kiev.ua> <18206408.GMLM77D01s@ralph.baldwin.cx> <20160829180454.GU83214@kib.kiev.ua> <a6921ce6-ca99-6ee9-24de-fe90a440879d@freebsd.org> <20160829191035.GV83214@kib.kiev.ua>
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On Mon, Aug 29, 2016 at 2:10 PM, Konstantin Belousov <kostikbel@gmail.com> 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 > The current > .Fn ptrace > -callers can reliably check > +implementation always sets > +.Va errno > +to 0 before calling into kernel, both for historic reasons and for > the kernel > +consistency with other operating systems. > +It is recommended to assign zero to > .Va errno > -for non-zero value afterwards. > +explicitely for future compatibility. > "explicitly" (only one 'e') Maybe forward compatibility instead of future compatibility, but either is fine. Feel free to commit with reviewed-by: bjk -Ben > .Sh ERRORS > The > .Fn ptrace > _______________________________________________ > 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-unsubscribe@freebsd.org" >
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