RE: Regarding select() on PPC

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

>-----Original Message-----
>From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
>Sent: Tuesday, September 23, 2008 10:26 AM
>To: Sadashiiv, Halesh
>Cc: Josh Boyer; linuxppc-embedded@ozlabs.org
>Subject: RE: Regarding select() on PPC
>
>On Tue, 2008-09-23 at 10:20 +0530, Sadashiiv, Halesh wrote:
>> Hi,
>>
>> The below testcase requires to exit with setting errno as EINVAL, as
per
>> the man page.
>>
>> I tested this on ARM, I686, PPC64 it was fine, for the same on PPC32
it
>> used exit with errno set as EFAULT.
>>
>> On further investigation found there was some long obsolete code in
>> arch/powerpc/kernel/syscalls.c (function ppc_select()), which was
>> written in 2.2.0 kernel for PPC32 specific , which resulted in
EFAULT.
>>
>> This needs to be verified, I have proposed patch for PPC32, Please
check
>> the link
>> http://article.gmane.org/gmane.linux.kernel/735922
>>
>
>I'm trying to sort out how obsolete it actually is and see if we can
>remove the whole thing.
>

Ok...once you verified please let me know.


>Your patch should be submitted to the linuxppc-dev mailing list btw.
>

Will do that.

>Ben.
>
>

Thanks,
Halesh


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RE: Regarding select() on PPC

[Benjamin Herrenschmidt]

> >Your patch should be submitted to the linuxppc-dev mailing list btw.
> >
> 
> Will do that.

Don't bother for now. The right approach would be to just
get rid of the wrappers I believe. I'm sorting that out.

Ben.

Re: Regarding select() on PPC

[Arnd Bergmann]

On Tuesday 23 September 2008, Sadashiiv, Halesh wrote:
> 
> >I'm trying to sort out how obsolete it actually is and see if we can
> >remove the whole thing.
> >
> 
> Ok...once you verified please let me know.
> 

I just did some more research. The bug was introduced with Linux-2.1.48,
the same version in which Pauls name first appeared as the PPC guy
in the MAINTAINERS file, over 11 years ago.

Before that, ppc used to have distinct implementations for oldselect
(__NR_select) and select (__NR__newselect), because initially it shared
the syscall numbers with i386 and that had replaced its oldselect
with newselect in 1.3.0.

In essence, oldselect was already obsolete before it was introduced
in the powerpc architecture, but for obscure reasons, some code
must have confused the two calling conventions, so Cort introduced
the wrapper that could handle either one, and used it for both
syscalls. This of course made it theoretically impossible to ever
fix the implementation without potentially breaking user space one
way or another.

The 32 bit emulation code never implemented a call behind __NR_select
or the oldselect calling conventions, so anything relying on
the legacy behaviour is broken there already.

I would definitely switch over the ppc32 __NR_newselect implementation
to sys_select. For __NR_select, there is no correct solution, the three
options are the current ppc_select, the real sys_select or sys_ni_syscall.
Each of these is broken in different ways, but in practice it will never
be called anyway.

I love archeology.

	Arnd <><

Re: Regarding select() on PPC

[Benjamin Herrenschmidt]

On Tue, 2008-09-23 at 07:46 +0200, Arnd Bergmann wrote:
> I would definitely switch over the ppc32 __NR_newselect implementation
> to sys_select. For __NR_select, there is no correct solution, the three
> options are the current ppc_select, the real sys_select or sys_ni_syscall.
> Each of these is broken in different ways, but in practice it will never
> be called anyway.
> 
> I love archeology.

Any idea when glibc got fixed ?

Ben

Re: Regarding select() on PPC

[Arnd Bergmann]

On Tuesday 23 September 2008, Benjamin Herrenschmidt wrote:
> On Tue, 2008-09-23 at 07:46 +0200, Arnd Bergmann wrote:
> > I would definitely switch over the ppc32 __NR_newselect implementation
> > to sys_select. For __NR_select, there is no correct solution, the three
> > options are the current ppc_select, the real sys_select or sys_ni_syscall.
> > Each of these is broken in different ways, but in practice it will never
> > be called anyway.
> > 
> > I love archeology.
> 
> Any idea when glibc got fixed ?
> 

No, sorry, I don't have a git history that I can search for that.
I have a strong guess that it would be the end of the last century
though, probably before 2.3.48, since the comment in there already
refers to legacy binaries.

	Arnd <><

Re: Regarding select() on PPC

[Benjamin Herrenschmidt]

On Tue, 2008-09-23 at 08:01 +0200, Arnd Bergmann wrote:
> No, sorry, I don't have a git history that I can search for that.
> I have a strong guess that it would be the end of the last century
> though, probably before 2.3.48, since the comment in there already
> refers to legacy binaries.

Yeah, I'm keen to rip it out.

Ben.

Re: Regarding select() on PPC

[Benjamin Herrenschmidt]

> If that is true, then _any_ syscall that takes an int value must have
> a ppc specific sign-extending compat wrapper, are you sure that is
> the case ?

Ok, so that's crap that has been bitrotting. We -do- need to sign extend
everywhere and it looks like we forgot to do it on anything recent, like
signalfd4...

Ben.

Re: Regarding select() on PPC

[Benjamin Herrenschmidt]

On Wed, 2008-09-24 at 08:45 +0200, Arnd Bergmann wrote:
> On Wednesday 24 September 2008, Benjamin Herrenschmidt wrote:
> > Why do we want it ?
> > 
> > It's an int, it's zero extended, but that should still be a valid signed
> > 32 bits int in compat_sys_select() or do I miss something ?
> 
> IIRC, the calling conventions on 64 bit ppc assume that a signed int
> argument is sign-extended into a 64 bit register. The compat syscall
> entry point does not know which registers are signed or unsigned, so
> it will always to zero-extend, making the register contain an undefined
> bit pattern (e.g. 0x00000000fffffffe), which may be interpreted as being
> a positive number. An explicit cast as it is done in ppc32_select turns
> this into a well-defined 32-bit number stored in a 64-bit register (e.g.
> 0xfffffffffffffffe).

If that is true, then _any_ syscall that takes an int value must have
a ppc specific sign-extending compat wrapper, are you sure that is
the case ?

Ben.

Re: Regarding select() on PPC

[Arnd Bergmann]

On Wednesday 24 September 2008, Benjamin Herrenschmidt wrote:
> Why do we want it ?
> 
> It's an int, it's zero extended, but that should still be a valid signed
> 32 bits int in compat_sys_select() or do I miss something ?

IIRC, the calling conventions on 64 bit ppc assume that a signed int
argument is sign-extended into a 64 bit register. The compat syscall
entry point does not know which registers are signed or unsigned, so
it will always to zero-extend, making the register contain an undefined
bit pattern (e.g. 0x00000000fffffffe), which may be interpreted as being
a positive number. An explicit cast as it is done in ppc32_select turns
this into a well-defined 32-bit number stored in a 64-bit register (e.g.
0xfffffffffffffffe).

	Arnd <><

Re: Regarding select() on PPC

[Benjamin Herrenschmidt]

On Wed, 2008-09-24 at 08:23 +0200, Arnd Bergmann wrote:
> On Tuesday 23 September 2008, Benjamin Herrenschmidt wrote:
> > 
> > > Means argument checking in ppc_select() can be removed??
> > > Than shall I post patch to linuxppc-dev@ozlabs.org
> > 
> > ppc_select can probably be removed alltogether and ppc32_select too
> 
> I think ppc32_select needs to stay. It never did the hack for
> supporting the old_select calling conventions, but it does the
> sign extension for the 32 bit arguments, which I think you still
> want.

Why do we want it ?

It's an int, it's zero extended, but that should still be a valid signed
32 bits int in compat_sys_select() or do I miss something ?
 
Ben.

> In any way, both the 32 bit emulation and the native ppc32 code
> path should do the same thing, which currently they don't.
> 
> 	Arnd <><

Re: Regarding select() on PPC

[Arnd Bergmann]

On Tuesday 23 September 2008, Benjamin Herrenschmidt wrote:
> 
> > Means argument checking in ppc_select() can be removed??
> > Than shall I post patch to linuxppc-dev@ozlabs.org
> 
> ppc_select can probably be removed alltogether and ppc32_select too

I think ppc32_select needs to stay. It never did the hack for
supporting the old_select calling conventions, but it does the
sign extension for the 32 bit arguments, which I think you still
want.

In any way, both the 32 bit emulation and the native ppc32 code
path should do the same thing, which currently they don't.

	Arnd <><

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

>-----Original Message-----
>From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
>Sent: Tuesday, September 23, 2008 2:38 PM
>To: Sadashiiv, Halesh
>Cc: Arnd Bergmann; linuxppc-embedded@ozlabs.org
>Subject: RE: Regarding select() on PPC
>
>On Tue, 2008-09-23 at 12:46 +0530, Sadashiiv, Halesh wrote:
>>
>> >-----Original Message-----
>> >From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
>> >Sent: Tuesday, September 23, 2008 12:00 PM
>> >To: Arnd Bergmann
>> >Cc: linuxppc-embedded@ozlabs.org; Sadashiiv, Halesh
>> >Subject: Re: Regarding select() on PPC
>> >
>> >On Tue, 2008-09-23 at 08:01 +0200, Arnd Bergmann wrote:
>> >> No, sorry, I don't have a git history that I can search for that.
>> >> I have a strong guess that it would be the end of the last century
>> >> though, probably before 2.3.48, since the comment in there already
>> >> refers to legacy binaries.
>> >
>> >Yeah, I'm keen to rip it out.
>>
>> Means argument checking in ppc_select() can be removed??
>> Than shall I post patch to linuxppc-dev@ozlabs.org
>
>ppc_select can probably be removed alltogether and ppc32_select too
>

Ok, directly sys_select() can be called instead of wrappers.

>Ben.
>
>

Halesh


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RE: Regarding select() on PPC

[Benjamin Herrenschmidt]

On Tue, 2008-09-23 at 12:46 +0530, Sadashiiv, Halesh wrote:
> 
> >-----Original Message-----
> >From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
> >Sent: Tuesday, September 23, 2008 12:00 PM
> >To: Arnd Bergmann
> >Cc: linuxppc-embedded@ozlabs.org; Sadashiiv, Halesh
> >Subject: Re: Regarding select() on PPC
> >
> >On Tue, 2008-09-23 at 08:01 +0200, Arnd Bergmann wrote:
> >> No, sorry, I don't have a git history that I can search for that.
> >> I have a strong guess that it would be the end of the last century
> >> though, probably before 2.3.48, since the comment in there already
> >> refers to legacy binaries.
> >
> >Yeah, I'm keen to rip it out.
> 
> Means argument checking in ppc_select() can be removed??
> Than shall I post patch to linuxppc-dev@ozlabs.org

ppc_select can probably be removed alltogether and ppc32_select too

Ben.

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

>-----Original Message-----
>From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
>Sent: Tuesday, September 23, 2008 12:00 PM
>To: Arnd Bergmann
>Cc: linuxppc-embedded@ozlabs.org; Sadashiiv, Halesh
>Subject: Re: Regarding select() on PPC
>
>On Tue, 2008-09-23 at 08:01 +0200, Arnd Bergmann wrote:
>> No, sorry, I don't have a git history that I can search for that.
>> I have a strong guess that it would be the end of the last century
>> though, probably before 2.3.48, since the comment in there already
>> refers to legacy binaries.
>
>Yeah, I'm keen to rip it out.

Means argument checking in ppc_select() can be removed??
Than shall I post patch to linuxppc-dev@ozlabs.org

>
>Ben.
>
>



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RE: Regarding select() on PPC

[Sadashiiv, Halesh]

>-----Original Message-----
>From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
>Sent: Tuesday, September 23, 2008 10:41 AM
>To: Sadashiiv, Halesh
>Cc: Josh Boyer; linuxppc-embedded@ozlabs.org
>Subject: RE: Regarding select() on PPC
>
>
>> >Your patch should be submitted to the linuxppc-dev mailing list btw.
>> >
>>
>> Will do that.
>
>Don't bother for now. The right approach would be to just
>get rid of the wrappers I believe. I'm sorting that out.
>

Ok.Will wait, thanks a lot

>Ben.
>
>


Halesh


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RE: Regarding select() on PPC

[Benjamin Herrenschmidt]

On Tue, 2008-09-23 at 10:20 +0530, Sadashiiv, Halesh wrote:
> Hi,
> 
> The below testcase requires to exit with setting errno as EINVAL, as per
> the man page.
> 
> I tested this on ARM, I686, PPC64 it was fine, for the same on PPC32 it
> used exit with errno set as EFAULT.
> 
> On further investigation found there was some long obsolete code in
> arch/powerpc/kernel/syscalls.c (function ppc_select()), which was
> written in 2.2.0 kernel for PPC32 specific , which resulted in EFAULT.
> 
> This needs to be verified, I have proposed patch for PPC32, Please check
> the link
> http://article.gmane.org/gmane.linux.kernel/735922
> 

I'm trying to sort out how obsolete it actually is and see if we can
remove the whole thing.

Your patch should be submitted to the linuxppc-dev mailing list btw.

Ben.

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

Hi,

The below testcase requires to exit with setting errno as EINVAL, as per
the man page.

I tested this on ARM, I686, PPC64 it was fine, for the same on PPC32 it
used exit with errno set as EFAULT.

On further investigation found there was some long obsolete code in
arch/powerpc/kernel/syscalls.c (function ppc_select()), which was
written in 2.2.0 kernel for PPC32 specific , which resulted in EFAULT.

This needs to be verified, I have proposed patch for PPC32, Please check
the link
http://article.gmane.org/gmane.linux.kernel/735922


Please find the below testcase.

#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <stdlib.h>

int main()
{

 int fd;
 fd_set rfds;
 struct timeval tv;
 int ret_val;

 if ((fd =3D open("test_file", O_RDWR|O_CREAT, 0664)) < 0)
  {
    printf("Open failed\n");
  }

  FD_ZERO(&rfds);
  FD_SET(fd, &rfds);

  /* Wait up to five seconds. */
  tv.tv_sec =3D 1;
  tv.tv_usec =3D 0;

  if ( (ret_val =3D select(-1, &rfds, NULL, NULL, &tv)) < 0)
  {
    if ( errno =3D=3D EINVAL)
      printf("OK\n");
    else
      printf("Not OK, Got errno %d\n", errno);
  }
  exit(0);
}


Thanks,
Halesh



>-----Original Message-----
>From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
>Sent: Tuesday, September 23, 2008 10:12 AM
>To: Josh Boyer
>Cc: Sadashiiv, Halesh; linuxppc-embedded@ozlabs.org
>Subject: Re: Regarding select() on PPC
>
>On Mon, 2008-09-22 at 11:24 -0400, Josh Boyer wrote:
>> On Mon, Sep 22, 2008 at 08:45:52PM +0530, Sadashiiv, Halesh wrote:
>> >
>> >
>> >The issue is found only in PPC32.
>> >
>> >Please let me if the patch is applicable.
>>
>> Well, no not really.  Mostly because of procedural issues than
anything
>> else.  Read Documentation/SubmittingPatches in the kernel directory.
>>
>> Also, there is a comment above this function that eludes to some
issues
>> with select on ppc32.  You might want to ask the overall PowerPC
>maintainer
>> if that issue still exits.
>
>I have only half of this thread, what is the problem ?
>
>Ben.
>
>



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Re: Regarding select() on PPC

[Benjamin Herrenschmidt]

On Mon, 2008-09-22 at 11:24 -0400, Josh Boyer wrote:
> On Mon, Sep 22, 2008 at 08:45:52PM +0530, Sadashiiv, Halesh wrote:
> >
> >
> >The issue is found only in PPC32.
> >
> >Please let me if the patch is applicable.
> 
> Well, no not really.  Mostly because of procedural issues than anything
> else.  Read Documentation/SubmittingPatches in the kernel directory.
> 
> Also, there is a comment above this function that eludes to some issues
> with select on ppc32.  You might want to ask the overall PowerPC maintainer
> if that issue still exits.

I have only half of this thread, what is the problem ?

Ben.

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

Thanks for the quick reply...

>-----Original Message-----
>From: Josh Boyer [mailto:jwboyer@gmail.com]
>Sent: Monday, September 22, 2008 8:55 PM
>To: Sadashiiv, Halesh
>Cc: linuxppc-embedded@ozlabs.org
>Subject: Re: Regarding select() on PPC
>
>On Mon, Sep 22, 2008 at 08:45:52PM +0530, Sadashiiv, Halesh wrote:
>>
>>
>>The issue is found only in PPC32.
>>
>>Please let me if the patch is applicable.
>
>Well, no not really.  Mostly because of procedural issues than anything
>else.  Read Documentation/SubmittingPatches in the kernel directory.

Will check the details.

>
>Also, there is a comment above this function that eludes to some issues
>with select on ppc32.  You might want to ask the overall PowerPC
maintainer
>if that issue still exits.

I have also posted in http://news.gmane.org/gmane.linux.kernel

http://article.gmane.org/gmane.linux.kernel/735618

Still no reply from any maintainer.

>
>josh


- Halesh



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Re: Regarding select() on PPC

[Josh Boyer]

On Mon, Sep 22, 2008 at 08:45:52PM +0530, Sadashiiv, Halesh wrote:
>
>
>The issue is found only in PPC32.
>
>Please let me if the patch is applicable.

Well, no not really.  Mostly because of procedural issues than anything
else.  Read Documentation/SubmittingPatches in the kernel directory.

Also, there is a comment above this function that eludes to some issues
with select on ppc32.  You might want to ask the overall PowerPC maintainer
if that issue still exits.

josh

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

The issue is found only in PPC32.

Please let me if the patch is applicable.

+++ arch/powerpc/kernel/syscalls.c      2008-09-22 20:47:23.885126056
+0530
@@ -211,6 +211,9 @@
 int
 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set
__user *exp, struct timeval __user *tvp)
 {
+   if ( n < 0 )
+       return -EINVAL;
+
    if ( (unsigned long)n >=3D 4096 )
    {
        unsigned long __user *buffer =3D (unsigned long __user *)n;

Thanks,
Halesh


>-----Original Message-----
>From: Josh Boyer [mailto:jwboyer@gmail.com]
>Sent: Friday, September 19, 2008 7:49 PM
>To: Sadashiiv, Halesh
>Cc: linuxppc-embedded@ozlabs.org
>Subject: Re: Regarding select() on PPC
>
>On Fri, Sep 19, 2008 at 07:00:07PM +0530, Sadashiiv, Halesh wrote:
>>>For negetive value of n (first argument to select) select fails with
>>EINVAL
>>>error,
>>>
>>>But for the same when I tested for PowerPC it was giving EFAULT,
>>>Its on 2.6.16 kernel.
>
>2.6.16 is really old.  I tested your testcase on a 2.6.25 based kernel
on
>a ppc64 machine and it seemed to work fine.
>
>josh



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Re: Regarding select() on PPC

[Dale Farnsworth]

I wrote:
> Interesting.  The man page for select says that select should return
> EINVAL when the first argument is negative.  By that, only ppc32 is
> correct.  :)

Sorry.  I should read before posting.  Please ignore my extraneous
comment above.

-Dale

Re: Regarding select() on PPC

[Dale Farnsworth]

> For negetive value of n (first argument to select) select fails with
> EINVAL error,
> 
> But for the same when I tested for PowerPC it was giving EFAULT, 
> Its on 2.6.16 kernel.
> 
> Please let me know, If this is fixed or it's a issue in PPC.
> For other archs its working fine.

Interesting.  The man page for select says that select should return
EINVAL when the first argument is negative.  By that, only ppc32 is
correct.  :)

-Dale

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

>-----Original Message-----
>From: Josh Boyer [mailto:jwboyer@gmail.com]
>Sent: Friday, September 19, 2008 7:49 PM
>To: Sadashiiv, Halesh
>Cc: linuxppc-embedded@ozlabs.org
>Subject: Re: Regarding select() on PPC
>
>On Fri, Sep 19, 2008 at 07:00:07PM +0530, Sadashiiv, Halesh wrote:
>>>For negetive value of n (first argument to select) select fails with
>>EINVAL
>>>error,
>>>
>>>But for the same when I tested for PowerPC it was giving EFAULT,
>>>Its on 2.6.16 kernel.
>
>2.6.16 is really old.  I tested your testcase on a 2.6.25 based kernel
on
>a ppc64 machine and it seemed to work fine.
>
>josh


Thanks for the info,

I am using PPC32, I think it doest not matters on 2.6.16 as I manually
checked the select source with 2.6.23 and no changes seen.
&
Even the same testcase passes on MIPS32 with 2.6.16.

Thanks
Halesh




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Re: Regarding select() on PPC

[Josh Boyer]

On Fri, Sep 19, 2008 at 07:00:07PM +0530, Sadashiiv, Halesh wrote:
>>For negetive value of n (first argument to select) select fails with
>EINVAL
>>error,
>>
>>But for the same when I tested for PowerPC it was giving EFAULT,
>>Its on 2.6.16 kernel.

2.6.16 is really old.  I tested your testcase on a 2.6.25 based kernel on
a ppc64 machine and it seemed to work fine.

josh

RE: Regarding select() on PPC

[Sadashiiv, Halesh]

>-----Original Message-----
>From: Sadashiiv, Halesh
>Sent: Friday, September 19, 2008 5:21 PM
>To: 'linuxppc-embedded@ozlabs.org'
>Subject: Regarding select() on PPC
>
>
>Hi all,
>
>Please find the below testcase.
>
>#include <stdio.h>
>#include <sys/time.h>
>#include <sys/types.h>
>#include <unistd.h>
>#include <fcntl.h>
>#include <string.h>
>#include <time.h>
>#include <errno.h>
>#include <stdlib.h>
>
>int main()
>{
>
> int fd;
> fd_set rfds;
> struct timeval tv;
> int ret_val;
>
> if ((fd =3D open("test_file", O_RDWR|O_CREAT, 0664)) < 0)
>  {
>    printf("Open failed\n");
>  }
>
>  FD_ZERO(&rfds);
>  FD_SET(fd, &rfds);
>
>  /* Wait up to five seconds. */
>  tv.tv_sec =3D 1;
>  tv.tv_usec =3D 0;
>
>  if ( (ret_val =3D select(-1, &rfds, NULL, NULL, &tv)) < 0)
>  {
>    if ( ret_val =3D=3D EINVAL)
=09
	if ( errno =3D=3D EINVAL)
Need to change it to errno, still not works.

>      printf("OK\n");
>    else
>      printf("Not OK, Got errno %d\n", errno);
>  }
>  exit(0);
>}
>
>
>For negetive value of n (first argument to select) select fails with
EINVAL
>error,
>
>But for the same when I tested for PowerPC it was giving EFAULT,
>Its on 2.6.16 kernel.
>
>Please let me know, If this is fixed or it's a issue in PPC.
>For other archs its working fine.
>
>
>Thanks,
>Halesh
>
>
>



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Regarding select() on PPC

[Sadashiiv, Halesh]

Hi all,

Please find the below testcase.

#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <stdlib.h>

int main()
{

 int fd;
 fd_set rfds;
 struct timeval tv;
 int ret_val;

 if ((fd =3D open("test_file", O_RDWR|O_CREAT, 0664)) < 0)
  {
    printf("Open failed\n");
  }

  FD_ZERO(&rfds);
  FD_SET(fd, &rfds);

  /* Wait up to five seconds. */
  tv.tv_sec =3D 1;
  tv.tv_usec =3D 0;

  if ( (ret_val =3D select(-1, &rfds, NULL, NULL, &tv)) < 0)
  {
    if ( ret_val =3D=3D EINVAL)
      printf("OK\n");
    else
      printf("Not OK, Got errno %d\n", errno);
  }
  exit(0);
}


For negetive value of n (first argument to select) select fails with
EINVAL error,

But for the same when I tested for PowerPC it was giving EFAULT,=20
Its on 2.6.16 kernel.

Please let me know, If this is fixed or it's a issue in PPC.
For other archs its working fine.


Thanks,
Halesh






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any dissemination, distribution or copying of this email is strictly =
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immediately by return email or telephone and destroy the original =
message. - This mail is sent via Sony Asia Pacific Mail Gateway.
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