From owner-freebsd-hackers@freebsd.org  Wed May 24 09:22:48 2017
Return-Path: <owner-freebsd-hackers@freebsd.org>
Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id ED210D7BE86
 for <freebsd-hackers@mailman.ysv.freebsd.org>;
 Wed, 24 May 2017 09:22:48 +0000 (UTC)
 (envelope-from karnajitw@gmail.com)
Received: from mail-qt0-x22f.google.com (mail-qt0-x22f.google.com
 [IPv6:2607:f8b0:400d:c0d::22f])
 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
 (Client CN "smtp.gmail.com",
 Issuer "Google Internet Authority G2" (verified OK))
 by mx1.freebsd.org (Postfix) with ESMTPS id A8C8B1F99
 for <freebsd-hackers@freebsd.org>; Wed, 24 May 2017 09:22:48 +0000 (UTC)
 (envelope-from karnajitw@gmail.com)
Received: by mail-qt0-x22f.google.com with SMTP id f55so149791537qta.3
 for <freebsd-hackers@freebsd.org>; Wed, 24 May 2017 02:22:48 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;
 h=mime-version:in-reply-to:references:from:date:message-id:subject:to
 :cc; bh=ZVUPQHk6r+aZVjELLrZxFvh7XE+x1Md170O/D79BC/w=;
 b=L0mUd9gm5KwfD5cMx4rc+l0P2K/B+GEuNpCFSdIUj9c2JQKlwsKEVmGXlHzuy7AvMg
 IcpZLKfd7Wn7OPIQR2iT1fBGuN1kH0AFOsiT38zEPT+2wBDl/jkRN/ZSzrBFAW/aQvoJ
 CMnXEqUt3o5BwzAujh+EYaR8Ji1aSbCwR70dRYLsqcwIOVyDp1BfzJY+j9raMJAgnbyG
 qzXn4IUETnO230gqe2ELuU07uYfqTrK8xvOSEGVfNQs6ZGEnS4z2u1pb+K8FhOcop6Cc
 N/LwHpRizdK4XfcO2FATu/VT/QO4QH9kh+vstTGYcbnY7tGua4gwYPd7k4u8wxFOfkQ4
 4vGQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20161025;
 h=x-gm-message-state:mime-version:in-reply-to:references:from:date
 :message-id:subject:to:cc;
 bh=ZVUPQHk6r+aZVjELLrZxFvh7XE+x1Md170O/D79BC/w=;
 b=dH6SeebP+GvdOAKKwjITXjKHoCG915JtbOJbaeuaa0o3Ie59sQZYznZYZUMR0UoWqZ
 g/JOq/swrazigodAFZUa/Ja4kdC5qPIgizG2gfgdQoUWLol8t+toX0kGiPGGk4lAM66w
 ImFF07UqGOvkenWBYQL498RDk/J9SiTThz5t2vzlXBY9lfVx857RTWmbNlc4MPEIOmqz
 T4lB2D+BqGETN39M14FNUiOifYm/fE+ZR4m6xY/WQT3zNPGRkQhvr/dw3ALoRXQW+GLP
 5XqF8qT9zssw5NA86ImKGpEZPYjntPhTXcysr2MH+8/DySaXRiSCwLs5/trbIsWtLENp
 ebfA==
X-Gm-Message-State: AODbwcD0YJNDitaiZyKTdERFTaz6EcXvFUdIrusO2hRq+TFO9/yB1QhQ
 ZS3Dw54/dJFeTTqpv/Keo3VO7JCoNg==
X-Received: by 10.200.34.132 with SMTP id f4mr32076370qta.183.1495617767881;
 Wed, 24 May 2017 02:22:47 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.200.49.85 with HTTP; Wed, 24 May 2017 02:22:47 -0700 (PDT)
In-Reply-To: <20170523140601.GD1622@kib.kiev.ua>
References: <CAB6rxaStKLXKFrQ2Lqa4gLDNM9CJeMXxDur6uTQC=_TGwZ_K_g@mail.gmail.com>
 <20170523140601.GD1622@kib.kiev.ua>
From: karnajit wangkhem <karnajitw@gmail.com>
Date: Wed, 24 May 2017 14:52:47 +0530
Message-ID: <CAB6rxaQeN-isnAGVGYH1vHhxHrrhUahRnaqrwJ4R0Xt=r7Uupw@mail.gmail.com>
Subject: Re: Seventh argument seen in mmap on i386
To: Konstantin Belousov <kostikbel@gmail.com>
Cc: freebsd-hackers@freebsd.org
X-Mailman-Approved-At: Wed, 24 May 2017 12:00:13 +0000
Content-Type: text/plain; charset="UTF-8"
X-Content-Filtered-By: Mailman/MimeDel 2.1.23
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 24 May 2017 09:22:49 -0000

Thanks. That was helpful.

On Tue, May 23, 2017 at 7:36 PM, Konstantin Belousov <kostikbel@gmail.com>
wrote:

> On Tue, May 23, 2017 at 07:25:07PM +0530, karnajit wangkhem wrote:
> > Hi All,
> >
> >
> >
> > I am trying to understand this scenario where a seventh argument is seen
> in
> > case of freebsd.x-i386. As per the mmap man page, the libc function
> > prototype takes in 6 arguments.
> >
> >
> > Ktrace shows the following
> >
> > // Freebsd-11.0 ??? i386 box
> >
> > 44416 a.out    CALL
> > mmap(0,0x1000,0x7<PROT_READ|PROT_WRITE|PROT_EXEC>,0x1002<
> MAP_PRIVATE|MAP_ANON>,0xffffffff,0,0)
> >
> > 44416 a.out    RET   mmap 671535104/0x2806d000
> >
> >
> >
> > // Freebsd-11.0 ??? amd64 box
> >
> > 366 a.out    CALL
> > mmap(0,0x1000,0x7<PROT_READ|PROT_WRITE|PROT_EXEC>,0x1002<
> MAP_PRIVATE|MAP_ANON>,0xffffffff,0)
> >
> > 366 a.out    RET   mmap 34366287872/0x80063f000
> >
> >
> >
> > Also, the disassemble code show that an extra argument was pushed in i386
> > case
> >
> > <SNIP>
> >
> > ->  0x80485e6 <+38>:  movl   %esp, %ebx
> >
> >     0x80485e8 <+40>:  movl   $0x0, 0x18(%ebx)
> >
> >     0x80485ef <+47>:  movl   $0x0, 0x14(%ebx)
> >
> >     0x80485f6 <+54>:  movl   $0xffffffff, 0x10(%ebx)   ; imm = 0xFFFFFFFF
> >
> >     0x80485fd <+61>:  movl   $0x1002, 0xc(%ebx)        ; imm = 0x1002
> >
> >     0x8048604 <+68>:  movl   $0x7, 0x8(%ebx)
> >
> >     0x804860b <+75>:  movl   $0x1000, 0x4(%ebx)        ; imm = 0x1000
> >
> >     0x8048612 <+82>:  movl   $0x0, (%ebx)
> >
> > <SNIP>
> >
> >
> >
> > Please help me understand why this extra argument is seen in case of
> i386.
>
> off_t is 64bit.  It is not seventh arg, it is offset which takes two words.
>