From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 22 Feb 2007 15:06:10 +0000 (GMT) Received: from mx.mips.com ([63.167.95.198]:23508 "EHLO dns0.mips.com") by ftp.linux-mips.org with ESMTP id S20038616AbXBVPGG (ORCPT ); Thu, 22 Feb 2007 15:06:06 +0000 Received: from mercury.mips.com (mercury [192.168.64.101]) by dns0.mips.com (8.12.11/8.12.11) with ESMTP id l1MExJJX029260; Thu, 22 Feb 2007 06:59:19 -0800 (PST) Received: from grendel (grendel [192.168.236.16]) by mercury.mips.com (8.13.5/8.13.5) with SMTP id l1MEwPCN014151; Thu, 22 Feb 2007 06:58:26 -0800 (PST) Message-ID: <01fc01c75693$195858b0$10eca8c0@grendel> From: "Kevin D. Kissell" To: "sathesh babu" , "Rajat Jain" Cc: References: <80178.32924.qm@web7903.mail.in.yahoo.com> Subject: Re: unaligned access Date: Thu, 22 Feb 2007 16:06:57 +0100 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_01F9_01C7569B.7A225B20" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1807 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1896 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 14203 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: kevink@mips.com Precedence: bulk X-list: linux-mips This is a multi-part message in MIME format. ------=_NextPart_000_01F9_01C7569B.7A225B20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Default behavior in MIPS is to silently fix up and emulate. A = MIPS-specific system call (sys_sysmips with the command argument of MIPS_FIXADE and a parameter agument of zero) allows for this to be overridden, so = that=20 such accesses will be fatal. It looks as if there was once support to = log the events=20 to syslog, independently of whether or not they were fixed up, but it = doesn't look to me=20 as if that still works in 2.6.x kernels. Regards, Kevin K. ----- Original Message -----=20 From: sathesh babu=20 To: Rajat Jain=20 Cc: linux-mips@linux-mips.org=20 Sent: Thursday, February 22, 2007 10:18 AM Subject: Re: unaligned access Thanks Rajan. In case of arm processor, the alignment trap behavior can be changed = by simply echo a number into /proc/sys/debug/alignment=20 bit behavior when set --- ----------------- 0 A user process performing an unaligned memory access will cause the kernel to print a message indicating process name, pid, pc, instruction, address, and the fault code. 1 The kernel will attempt to fix up the user process performing the unaligned access. This is of course slow (think about the floating point emulator) and not recommended for production use. 2 The kernel will send a SIGBUS signal to the user = process performing the unaligned access. I would like to know Is there similar type of implimentation = avalilable for MIPS processor in linux-2.6.12 kernel to view or log the = unaligned access addresses and corresponding processor ID. Regards, Sathesh Rajat Jain wrote: On 2/22/07, sathesh babu wrote: > Hi, > I have ported linux-2.6.12 kernel on MIPS processor.I would like = to > print the warning messges whenenver kernel or user code try to = access > unaligned address ( including proceor ID ). > Is there any configuration option avaliable in the kernel to view > the unaligned address? Ummm ... not sure about MIPS, but in i386, exception 17 is raised = for every unaligned access. alignment_check() is invoked for every such access. Regards, Rajat -------------------------------------------------------------------------= ----- Here's a new way to find what you're looking for - Yahoo! Answers ------=_NextPart_000_01F9_01C7569B.7A225B20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Default behavior in MIPS is to silently = fix up and=20 emulate.  A MIPS-specific
system call (sys_sysmips with the = command argument=20 of MIPS_FIXADE
and a parameter agument of zero) = allows for this to be overridden, so = that 
such accesses will be fatal.  It = looks as=20 if there was once support to log the = events=20
to syslog, independently of whether = or not they were fixed up, but it doesn't look to = me=20
as if that still works in 2.6.x = kernels.
 
    =20        Regards,
 
       =20     Kevin K.
----- Original Message -----
From:=20 sathesh babu
Sent: Thursday, February 22, = 2007 10:18=20 AM
Subject: Re: unaligned = access

Thanks Rajan.
 
In case of arm processor, the alignment trap behavior can be = changed by=20 simply echo a number into  /proc/sys/debug/alignment 
 
=
bit           = ; =20 behavior when=20 = set
---          &nb= sp; =20 -----------------
=
0           &= nbsp;  =20 A user process performing an unaligned memory=20 = access
          &nb= sp;    =20 will cause the kernel to print a message=20 = indicating
          = ;     =20 process name, pid, pc, instruction, address, and=20 = the
           =     =20 fault code.
=
1           &= nbsp;  =20 The kernel will attempt to fix up the user=20 = process
          &n= bsp;    =20 performing the unaligned access.  This is of=20 = course
          &nb= sp;    =20 slow (think about the floating point emulator)=20 = and
           =     =20 not recommended for production use.
=
2           &= nbsp;  =20 The kernel will send a SIGBUS signal to the user=20 = process
          &n= bsp;    =20 performing the unaligned access.

I would like to know  Is = there=20 similar type of implimentation avalilable for MIPS processor in = linux-2.6.12=20 kernel to view or log the unaligned access addresses and corresponding = processor ID.
 
Regards,
Sathesh
 

Rajat Jain <rajat.noida.india@gmail.com>=20 wrote:
On=20 2/22/07, sathesh babu wrote:
>=20 Hi,
> I have ported linux-2.6.12 kernel on MIPS processor.I = would like=20 to
> print the warning messges whenenver kernel or user code = try to=20 access
> unaligned address ( including proceor ID ).
> = Is there=20 any configuration option avaliable in the kernel to view
> the = unaligned address?

Ummm ... not sure about MIPS, but in i386, = exception 17 is raised for
every unaligned access. = alignment_check() is=20 invoked for every=20 such
access.

Regards,

Rajat


Here=92s a new way to find what you're looking for - Yahoo!=20 Answers ------=_NextPart_000_01F9_01C7569B.7A225B20-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.mips.com ([63.167.95.198]:23508 "EHLO dns0.mips.com") by ftp.linux-mips.org with ESMTP id S20038616AbXBVPGG (ORCPT ); Thu, 22 Feb 2007 15:06:06 +0000 Message-ID: <01fc01c75693$195858b0$10eca8c0@grendel> From: "Kevin D. Kissell" References: <80178.32924.qm@web7903.mail.in.yahoo.com> Subject: Re: unaligned access Date: Thu, 22 Feb 2007 16:06:57 +0100 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_01F9_01C7569B.7A225B20" Return-Path: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org To: sathesh babu , Rajat Jain Cc: linux-mips@linux-mips.org Message-ID: <20070222150657.5AiLoRmGlaqnnpgUObuh231cs2zv6v1ReHKnWnKsI6k@z> This is a multi-part message in MIME format. ------=_NextPart_000_01F9_01C7569B.7A225B20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Default behavior in MIPS is to silently fix up and emulate. A = MIPS-specific system call (sys_sysmips with the command argument of MIPS_FIXADE and a parameter agument of zero) allows for this to be overridden, so = that=20 such accesses will be fatal. It looks as if there was once support to = log the events=20 to syslog, independently of whether or not they were fixed up, but it = doesn't look to me=20 as if that still works in 2.6.x kernels. Regards, Kevin K. ----- Original Message -----=20 From: sathesh babu=20 To: Rajat Jain=20 Cc: linux-mips@linux-mips.org=20 Sent: Thursday, February 22, 2007 10:18 AM Subject: Re: unaligned access Thanks Rajan. In case of arm processor, the alignment trap behavior can be changed = by simply echo a number into /proc/sys/debug/alignment=20 bit behavior when set --- ----------------- 0 A user process performing an unaligned memory access will cause the kernel to print a message indicating process name, pid, pc, instruction, address, and the fault code. 1 The kernel will attempt to fix up the user process performing the unaligned access. This is of course slow (think about the floating point emulator) and not recommended for production use. 2 The kernel will send a SIGBUS signal to the user = process performing the unaligned access. I would like to know Is there similar type of implimentation = avalilable for MIPS processor in linux-2.6.12 kernel to view or log the = unaligned access addresses and corresponding processor ID. Regards, Sathesh Rajat Jain wrote: On 2/22/07, sathesh babu wrote: > Hi, > I have ported linux-2.6.12 kernel on MIPS processor.I would like = to > print the warning messges whenenver kernel or user code try to = access > unaligned address ( including proceor ID ). > Is there any configuration option avaliable in the kernel to view > the unaligned address? Ummm ... not sure about MIPS, but in i386, exception 17 is raised = for every unaligned access. alignment_check() is invoked for every such access. Regards, Rajat -------------------------------------------------------------------------= ----- Here's a new way to find what you're looking for - Yahoo! Answers ------=_NextPart_000_01F9_01C7569B.7A225B20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Default behavior in MIPS is to silently = fix up and=20 emulate.  A MIPS-specific
system call (sys_sysmips with the = command argument=20 of MIPS_FIXADE
and a parameter agument of zero) = allows for this to be overridden, so = that 
such accesses will be fatal.  It = looks as=20 if there was once support to log the = events=20
to syslog, independently of whether = or not they were fixed up, but it doesn't look to = me=20
as if that still works in 2.6.x = kernels.
 
    =20        Regards,
 
       =20     Kevin K.
----- Original Message -----
From:=20 sathesh babu
Sent: Thursday, February 22, = 2007 10:18=20 AM
Subject: Re: unaligned = access

Thanks Rajan.
 
In case of arm processor, the alignment trap behavior can be = changed by=20 simply echo a number into  /proc/sys/debug/alignment 
 
=
bit           = ; =20 behavior when=20 = set
---          &nb= sp; =20 -----------------
=
0           &= nbsp;  =20 A user process performing an unaligned memory=20 = access
          &nb= sp;    =20 will cause the kernel to print a message=20 = indicating
          = ;     =20 process name, pid, pc, instruction, address, and=20 = the
           =     =20 fault code.
=
1           &= nbsp;  =20 The kernel will attempt to fix up the user=20 = process
          &n= bsp;    =20 performing the unaligned access.  This is of=20 = course
          &nb= sp;    =20 slow (think about the floating point emulator)=20 = and
           =     =20 not recommended for production use.
=
2           &= nbsp;  =20 The kernel will send a SIGBUS signal to the user=20 = process
          &n= bsp;    =20 performing the unaligned access.

I would like to know  Is = there=20 similar type of implimentation avalilable for MIPS processor in = linux-2.6.12=20 kernel to view or log the unaligned access addresses and corresponding = processor ID.
 
Regards,
Sathesh
 

Rajat Jain <rajat.noida.india@gmail.com>=20 wrote:
On=20 2/22/07, sathesh babu wrote:
>=20 Hi,
> I have ported linux-2.6.12 kernel on MIPS processor.I = would like=20 to
> print the warning messges whenenver kernel or user code = try to=20 access
> unaligned address ( including proceor ID ).
> = Is there=20 any configuration option avaliable in the kernel to view
> the = unaligned address?

Ummm ... not sure about MIPS, but in i386, = exception 17 is raised for
every unaligned access. = alignment_check() is=20 invoked for every=20 such
access.

Regards,

Rajat


Here=92s a new way to find what you're looking for - Yahoo!=20 Answers ------=_NextPart_000_01F9_01C7569B.7A225B20--