[PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Chris Snook]

From: Chris Snook <csnook@redhat.com>

POSIX states that poll() shall fail with EINVAL if nfds > OPEN_MAX.  In this
context, POSIX is referring to sysconf(OPEN_MAX), which is the value of
current->rlim[RLIMIT_NOFILE].rlim_cur, not the compile-time constant which
happens to be named OPEN_MAX.  The current code will permit polling up to 1024
file descriptors even if RLIMIT_NOFILE is less than 1024, which POSIX forbids.
 The current code also breaks polling greater than 1024 file descriptors if
the process has less than 1024 valid descriptors, even if RLIMIT_NOFILE >
1024.  While it is silly to poll duplicate or invalid file descriptors, POSIX
permits this, and it worked circa 2.4.18, and currently works up to 1024.
This patch directly checks the RLIMIT_NOFILE value, and permits exactly what
POSIX suggests, no more, no less.

Signed-off-by: Chris Snook <csnook@redhat.com>
---

diff -urNp linux-2.4.33.2-orig/fs/select.c linux-2.4.33.2-patch/fs/select.c
--- linux-2.4.33.2-orig/fs/select.c	2006-08-22 16:13:54.000000000 -0400
+++ linux-2.4.33.2-patch/fs/select.c	2006-08-31 13:43:39.000000000 -0400
@@ -417,7 +417,7 @@ asmlinkage long sys_poll(struct pollfd *
 	int nchunks, nleft;

 	/* Do a sanity check on nfds ... */
-	if (nfds > current->files->max_fdset && nfds > OPEN_MAX)
+	if (nfds > current->rlim[RLIMIT_NOFILE].rlim_cur)
 		return -EINVAL;

 	if (timeout) {

Re: [PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Willy Tarreau]

Hi Chris,

On Thu, Aug 31, 2006 at 09:06:55PM -0400, Chris Snook wrote:
> From: Chris Snook <csnook@redhat.com>
> 
> POSIX states that poll() shall fail with EINVAL if nfds > OPEN_MAX.  In this
> context, POSIX is referring to sysconf(OPEN_MAX), which is the value of
> current->rlim[RLIMIT_NOFILE].rlim_cur, not the compile-time constant which
> happens to be named OPEN_MAX.  The current code will permit polling up to 1024
> file descriptors even if RLIMIT_NOFILE is less than 1024, which POSIX forbids.
>  The current code also breaks polling greater than 1024 file descriptors if
> the process has less than 1024 valid descriptors, even if RLIMIT_NOFILE >
> 1024.  While it is silly to poll duplicate or invalid file descriptors, POSIX
> permits this, and it worked circa 2.4.18, and currently works up to 1024.
> This patch directly checks the RLIMIT_NOFILE value, and permits exactly what
> POSIX suggests, no more, no less.

While I understand that it was a bug before, I fear that it could break
existing apps. Are you aware of some apps which do not work as expected
because of this bug ? If not, I'd prefer to wait for some feedback from
2.6 with this fix before applying it (or maybe you're already using it
in RHEL with success ?).

Thanks,
Willy

> Signed-off-by: Chris Snook <csnook@redhat.com>
> ---
> 
> diff -urNp linux-2.4.33.2-orig/fs/select.c linux-2.4.33.2-patch/fs/select.c
> --- linux-2.4.33.2-orig/fs/select.c	2006-08-22 16:13:54.000000000 -0400
> +++ linux-2.4.33.2-patch/fs/select.c	2006-08-31 13:43:39.000000000 -0400
> @@ -417,7 +417,7 @@ asmlinkage long sys_poll(struct pollfd *
>  	int nchunks, nleft;
> 
>  	/* Do a sanity check on nfds ... */
> -	if (nfds > current->files->max_fdset && nfds > OPEN_MAX)
> +	if (nfds > current->rlim[RLIMIT_NOFILE].rlim_cur)
>  		return -EINVAL;
> 
>  	if (timeout) {

Re: [PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Vadim Lobanov]

On Thursday 31 August 2006 20:48, Willy Tarreau wrote:
> Hi Chris,
>
> On Thu, Aug 31, 2006 at 09:06:55PM -0400, Chris Snook wrote:
> > From: Chris Snook <csnook@redhat.com>
> >
> > POSIX states that poll() shall fail with EINVAL if nfds > OPEN_MAX.  In
> > this context, POSIX is referring to sysconf(OPEN_MAX), which is the value
> > of current->rlim[RLIMIT_NOFILE].rlim_cur, not the compile-time constant
> > which happens to be named OPEN_MAX.  The current code will permit polling
> > up to 1024 file descriptors even if RLIMIT_NOFILE is less than 1024,
> > which POSIX forbids. The current code also breaks polling greater than
> > 1024 file descriptors if the process has less than 1024 valid
> > descriptors, even if RLIMIT_NOFILE > 1024.  While it is silly to poll
> > duplicate or invalid file descriptors, POSIX permits this, and it worked
> > circa 2.4.18, and currently works up to 1024. This patch directly checks
> > the RLIMIT_NOFILE value, and permits exactly what POSIX suggests, no
> > more, no less.
>
> While I understand that it was a bug before, I fear that it could break
> existing apps. Are you aware of some apps which do not work as expected
> because of this bug ? If not, I'd prefer to wait for some feedback from
> 2.6 with this fix before applying it (or maybe you're already using it
> in RHEL with success ?).

I submitted a similar but different patch for this very same issue against the 
2.6 kernel. It's currently residing in the -mm tree. Andrew Morton is 
somewhat reticent (and understandably so) to push it quickly into the vanilla 
tree; but, for what it's worth, I've yet to hear -- either directly or 
indirectly -- of any application breakages caused by this fix.

> Thanks,
> Willy
>
> > Signed-off-by: Chris Snook <csnook@redhat.com>
> > ---
> >
> > diff -urNp linux-2.4.33.2-orig/fs/select.c
> > linux-2.4.33.2-patch/fs/select.c ---
> > linux-2.4.33.2-orig/fs/select.c	2006-08-22 16:13:54.000000000 -0400 +++
> > linux-2.4.33.2-patch/fs/select.c	2006-08-31 13:43:39.000000000 -0400 @@
> > -417,7 +417,7 @@ asmlinkage long sys_poll(struct pollfd *
> >  	int nchunks, nleft;
> >
> >  	/* Do a sanity check on nfds ... */
> > -	if (nfds > current->files->max_fdset && nfds > OPEN_MAX)
> > +	if (nfds > current->rlim[RLIMIT_NOFILE].rlim_cur)
> >  		return -EINVAL;
> >
> >  	if (timeout) {
>

-- Vadim Lobanov

Re: [PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Chris Snook]

Re: [PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Chris Snook]

Sorry about the blank post last night.  Looks like my non-patch-mangling 
webmailer has a UTF-8/ASCII conversion bug that eats messages.  If 
anyone can recommend completely reliable mail clients for posting here, 
they'd be a good addition to the lkml.org FAQ

Comments inline...

Vadim Lobanov wrote:
> On Thursday 31 August 2006 20:48, Willy Tarreau wrote:
> 
>>Hi Chris,
>>
>>On Thu, Aug 31, 2006 at 09:06:55PM -0400, Chris Snook wrote:
>>
>>>From: Chris Snook <csnook@redhat.com>
>>>
>>>POSIX states that poll() shall fail with EINVAL if nfds > OPEN_MAX.  In
>>>this context, POSIX is referring to sysconf(OPEN_MAX), which is the value
>>>of current->rlim[RLIMIT_NOFILE].rlim_cur, not the compile-time constant
>>>which happens to be named OPEN_MAX.  The current code will permit polling
>>>up to 1024 file descriptors even if RLIMIT_NOFILE is less than 1024,
>>>which POSIX forbids. The current code also breaks polling greater than
>>>1024 file descriptors if the process has less than 1024 valid
>>>descriptors, even if RLIMIT_NOFILE > 1024.  While it is silly to poll
>>>duplicate or invalid file descriptors, POSIX permits this, and it worked
>>>circa 2.4.18, and currently works up to 1024. This patch directly checks
>>>the RLIMIT_NOFILE value, and permits exactly what POSIX suggests, no
>>>more, no less.
>>
>>While I understand that it was a bug before, I fear that it could break
>>existing apps. Are you aware of some apps which do not work as expected
>>because of this bug ? If not, I'd prefer to wait for some feedback from
>>2.6 with this fix before applying it (or maybe you're already using it
>>in RHEL with success ?).
> 
> 
> I submitted a similar but different patch for this very same issue against the 
> 2.6 kernel. It's currently residing in the -mm tree. Andrew Morton is 
> somewhat reticent (and understandably so) to push it quickly into the vanilla 
> tree; but, for what it's worth, I've yet to hear -- either directly or 
> indirectly -- of any application breakages caused by this fix.

Willy and Vadim --

	We have received reports of apps which poll a large set of 
not-necessarily-valid file descriptors which worked fine under 2.4.18, 
when the check was only against NR_OPEN, which is 1024*1024, that fail 
under newer kernels.  So there is a real motivation to change the 
current code.  As for the patch breaking existing apps, there are really 
3 scenarios:

1)	RLIMIT_NOFILE is at the default value of 1024

	In this (default) case, the patch changes nothing.  Calls with nfds > 
1024 fail with EINVAL both before and after the patch, and calls with 
nfds <= 1024 pass the check both before and after the patch, since 1024 
is the initial value of max_fdset.

2)	RLIMIT_NOFILE has been raised above the default

	In this case, poll() becomes more permissive, allowing polling up to 
RLIMIT_NOFILE file descriptors even if less than 1024 have been opened. 
  The patch won't introduce new errors here.  If an application somehow 
depends on poll() failing when it polls with duplicate or invalid file 
descriptors, it's already broken, since this is already allowed below 
1024, and will also work above 1024 if enough file descriptors have been 
open at some point to cause max_fdset to have been increased above nfds.

3)	RLIMIT_NOFILE has been lowered below the default

	In this case, the system administrator or the user has gone out of 
their way to protect the system from inefficient (or malicious) 
applications wasting kernel memory.  The current code allows polling up 
to 1024 file descriptors even if RLIMIT_NOFILE is much lower, which is 
not what the user or administrator intended.  Well-written applications 
which only poll valid, unique file descriptors will never notice the 
difference, because they'll hit the limit on open() first.  If an 
application gets broken because of the patch in this case, then it was 
already poorly/maliciously designed, and allowing it to work in the past 
was a violation of POSIX and a DoS risk on low-resource systems.

	-- Chris

>>Thanks,
>>Willy
>>
>>
>>>Signed-off-by: Chris Snook <csnook@redhat.com>
>>>---
>>>
>>>diff -urNp linux-2.4.33.2-orig/fs/select.c
>>>linux-2.4.33.2-patch/fs/select.c ---
>>>linux-2.4.33.2-orig/fs/select.c	2006-08-22 16:13:54.000000000 -0400 +++
>>>linux-2.4.33.2-patch/fs/select.c	2006-08-31 13:43:39.000000000 -0400 @@
>>>-417,7 +417,7 @@ asmlinkage long sys_poll(struct pollfd *
>>> 	int nchunks, nleft;
>>>
>>> 	/* Do a sanity check on nfds ... */
>>>-	if (nfds > current->files->max_fdset && nfds > OPEN_MAX)
>>>+	if (nfds > current->rlim[RLIMIT_NOFILE].rlim_cur)
>>> 		return -EINVAL;
>>>
>>> 	if (timeout) {
>>
> 
> -- Vadim Lobanov

Re: [PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Willy Tarreau]

On Fri, Sep 01, 2006 at 12:03:24PM -0400, Chris Snook wrote:
> Sorry about the blank post last night.  Looks like my non-patch-mangling 
> webmailer has a UTF-8/ASCII conversion bug that eats messages.

pfff... this stupid utf8 again... and it's not going to disappear
unfortunately :-(  The day we will vote for the worst invention of
the last 20 years, it might get lots of voices !

> If 
> anyone can recommend completely reliable mail clients for posting here, 
> they'd be a good addition to the lkml.org FAQ

[OT]
I use mutt (and get laughed at at work), many others use pine (and
probably hear the same hilarious ignorants). Simple, fast, stupid
enough for me. Not well suited to classify lists in folders, but
still fast, considering that I achieve to manually and accurately
delete 2800 spams in the middle of ham in less than 30 minutes.
[/OT]

> Comments inline...
> 
> Vadim Lobanov wrote:
> >On Thursday 31 August 2006 20:48, Willy Tarreau wrote:
> >
> >>Hi Chris,
> >>
> >>On Thu, Aug 31, 2006 at 09:06:55PM -0400, Chris Snook wrote:
> >>
> >>>From: Chris Snook <csnook@redhat.com>
> >>>
> >>>POSIX states that poll() shall fail with EINVAL if nfds > OPEN_MAX.  In
> >>>this context, POSIX is referring to sysconf(OPEN_MAX), which is the value
> >>>of current->rlim[RLIMIT_NOFILE].rlim_cur, not the compile-time constant
> >>>which happens to be named OPEN_MAX.  The current code will permit polling
> >>>up to 1024 file descriptors even if RLIMIT_NOFILE is less than 1024,
> >>>which POSIX forbids. The current code also breaks polling greater than
> >>>1024 file descriptors if the process has less than 1024 valid
> >>>descriptors, even if RLIMIT_NOFILE > 1024.  While it is silly to poll
> >>>duplicate or invalid file descriptors, POSIX permits this, and it worked
> >>>circa 2.4.18, and currently works up to 1024. This patch directly checks
> >>>the RLIMIT_NOFILE value, and permits exactly what POSIX suggests, no
> >>>more, no less.
> >>
> >>While I understand that it was a bug before, I fear that it could break
> >>existing apps. Are you aware of some apps which do not work as expected
> >>because of this bug ? If not, I'd prefer to wait for some feedback from
> >>2.6 with this fix before applying it (or maybe you're already using it
> >>in RHEL with success ?).
> >
> >
> >I submitted a similar but different patch for this very same issue against 
> >the 2.6 kernel. It's currently residing in the -mm tree. Andrew Morton is 
> >somewhat reticent (and understandably so) to push it quickly into the 
> >vanilla tree; but, for what it's worth, I've yet to hear -- either 
> >directly or indirectly -- of any application breakages caused by this fix.
> 
> Willy and Vadim --
> 
> 	We have received reports of apps which poll a large set of 
> not-necessarily-valid file descriptors which worked fine under 2.4.18, 
> when the check was only against NR_OPEN, which is 1024*1024, that fail 
> under newer kernels.  So there is a real motivation to change the 
> current code.  As for the patch breaking existing apps, there are really 
> 3 scenarios:
> 
> 1)	RLIMIT_NOFILE is at the default value of 1024
> 
> 	In this (default) case, the patch changes nothing.  Calls with nfds 
> 	> 1024 fail with EINVAL both before and after the patch, and calls with 
> nfds <= 1024 pass the check both before and after the patch, since 1024 
> is the initial value of max_fdset.
> 
> 2)	RLIMIT_NOFILE has been raised above the default
> 
> 	In this case, poll() becomes more permissive, allowing polling up to 
> RLIMIT_NOFILE file descriptors even if less than 1024 have been opened. 
>  The patch won't introduce new errors here.  If an application somehow 
> depends on poll() failing when it polls with duplicate or invalid file 
> descriptors, it's already broken, since this is already allowed below 
> 1024, and will also work above 1024 if enough file descriptors have been 
> open at some point to cause max_fdset to have been increased above nfds.
> 
> 3)	RLIMIT_NOFILE has been lowered below the default
> 
> 	In this case, the system administrator or the user has gone out of 
> their way to protect the system from inefficient (or malicious) 
> applications wasting kernel memory.  The current code allows polling up 
> to 1024 file descriptors even if RLIMIT_NOFILE is much lower, which is 
> not what the user or administrator intended.  Well-written applications 
> which only poll valid, unique file descriptors will never notice the 
> difference, because they'll hit the limit on open() first.  If an 
> application gets broken because of the patch in this case, then it was 
> already poorly/maliciously designed, and allowing it to work in the past 
> was a violation of POSIX and a DoS risk on low-resource systems.

OK, thanks very much for the details. Now, call me an idiot, but why
don't you consider broken the apps which are currently failing on
newer kernels ? I'm starting to suspect that we have to sets of apps :

  - those which rely on poll() failing for invalid fds (do they really
    exist ?)
  - those which rely on poll() not failing for invalid fds.

The poll(2) man page suggests what you're saying. Man pages from other
OSes found on the net suggest various behaviours. I guess it's better
to stick to what has been documented (ie: your fix) but with *infinite
care*. Apps which need more than 1024 fds are not end-user mp3 players.
Breaking them in a stable branch can have a huge impact. I'd like this
patch to be tested in 2.6 long before 2.4, and also it would be good
if we could find some feedback from affected people which could confirm
that your patch really fixes their problems. If you have some customers
reporting the problem in RHEL who confirm the fix, it would be nice if
they accepted to inform us about the application(s) which need this fix. 

> 	-- Chris

Thanks,
Willy

Re: [PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Willy Tarreau]

On Fri, Sep 01, 2006 at 05:24:01PM -0400, Chris Snook wrote:
> Willy Tarreau wrote:
> >On Fri, Sep 01, 2006 at 12:03:24PM -0400, Chris Snook wrote:
> >>Willy and Vadim --
> >>
> >>	We have received reports of apps which poll a large set of 
> >>not-necessarily-valid file descriptors which worked fine under 2.4.18, 
> >>when the check was only against NR_OPEN, which is 1024*1024, that fail 
> >>under newer kernels.  So there is a real motivation to change the 
> >>current code.  As for the patch breaking existing apps, there are really 
> >>3 scenarios:
> >>
> >>1)	RLIMIT_NOFILE is at the default value of 1024
> >>
> >>	In this (default) case, the patch changes nothing.  Calls with nfds 
> >>	> 1024 fail with EINVAL both before and after the patch, and calls 
> >>	with nfds <= 1024 pass the check both before and after the patch, since 
> >>1024 is the initial value of max_fdset.
> >>
> >>2)	RLIMIT_NOFILE has been raised above the default
> >>
> >>	In this case, poll() becomes more permissive, allowing polling up to 
> >>RLIMIT_NOFILE file descriptors even if less than 1024 have been opened. 
> >>The patch won't introduce new errors here.  If an application somehow 
> >>depends on poll() failing when it polls with duplicate or invalid file 
> >>descriptors, it's already broken, since this is already allowed below 
> >>1024, and will also work above 1024 if enough file descriptors have been 
> >>open at some point to cause max_fdset to have been increased above nfds.
> >>
> >>3)	RLIMIT_NOFILE has been lowered below the default
> >>
> >>	In this case, the system administrator or the user has gone out of 
> >>their way to protect the system from inefficient (or malicious) 
> >>applications wasting kernel memory.  The current code allows polling up 
> >>to 1024 file descriptors even if RLIMIT_NOFILE is much lower, which is 
> >>not what the user or administrator intended.  Well-written applications 
> >>which only poll valid, unique file descriptors will never notice the 
> >>difference, because they'll hit the limit on open() first.  If an 
> >>application gets broken because of the patch in this case, then it was 
> >>already poorly/maliciously designed, and allowing it to work in the past 
> >>was a violation of POSIX and a DoS risk on low-resource systems.
> >
> >
> >OK, thanks very much for the details. Now, call me an idiot, but why
> >don't you consider broken the apps which are currently failing on
> >newer kernels ? I'm starting to suspect that we have to sets of apps :
> 
> I do consider them poorly designed, but they're out there, and they used 
> to work, and it doesn't violate POSIX to allow them to work again, so 
> all things being equal, I'd like them to work on new kernels.
> 
> >  - those which rely on poll() failing for invalid fds (do they really
> >    exist ?)
> 
> I hope not.  If so, they're already broken in most situations anyway.
> 
> >  - those which rely on poll() not failing for invalid fds.
> 
> This is what we've gotten reports of.  I suspect we haven't heard much 
> about this because in most cases the offending apps get fixed to not 
> poll invalid fds, but for some deployed proprietary apps that may not be 
> an option.
> 
> >The poll(2) man page suggests what you're saying. Man pages from other
> >OSes found on the net suggest various behaviours. I guess it's better
> >to stick to what has been documented (ie: your fix) but with *infinite
> >care*. Apps which need more than 1024 fds are not end-user mp3 players.
> >Breaking them in a stable branch can have a huge impact. I'd like this
> >patch to be tested in 2.6 long before 2.4, and also it would be good
> >if we could find some feedback from affected people which could confirm
> >that your patch really fixes their problems. If you have some customers
> >reporting the problem in RHEL who confirm the fix, it would be nice if
> >they accepted to inform us about the application(s) which need this fix. 
> 
> I agree.  The 2.6 patch is in -mm now.  The patch has been tested 
> successfully with a synthetic reproducer under various vanilla and RHEL 
> 2.4 and 2.6 kernels, but we're still waiting on real-world customer 
> results.  Let's wait and see how the customer tests and the -mm patch go.

OK Chris,

let's wait and see then !

Regards,
Willy


-- 
VGER BF report: H 0

Re: [PATCH 2.4.33.2] enforce RLIMIT_NOFILE in poll()

[Chris Snook]

Willy Tarreau wrote:
> On Fri, Sep 01, 2006 at 12:03:24PM -0400, Chris Snook wrote:
>>Willy and Vadim --
>>
>>	We have received reports of apps which poll a large set of 
>>not-necessarily-valid file descriptors which worked fine under 2.4.18, 
>>when the check was only against NR_OPEN, which is 1024*1024, that fail 
>>under newer kernels.  So there is a real motivation to change the 
>>current code.  As for the patch breaking existing apps, there are really 
>>3 scenarios:
>>
>>1)	RLIMIT_NOFILE is at the default value of 1024
>>
>>	In this (default) case, the patch changes nothing.  Calls with nfds 
>>	> 1024 fail with EINVAL both before and after the patch, and calls with 
>>nfds <= 1024 pass the check both before and after the patch, since 1024 
>>is the initial value of max_fdset.
>>
>>2)	RLIMIT_NOFILE has been raised above the default
>>
>>	In this case, poll() becomes more permissive, allowing polling up to 
>>RLIMIT_NOFILE file descriptors even if less than 1024 have been opened. 
>> The patch won't introduce new errors here.  If an application somehow 
>>depends on poll() failing when it polls with duplicate or invalid file 
>>descriptors, it's already broken, since this is already allowed below 
>>1024, and will also work above 1024 if enough file descriptors have been 
>>open at some point to cause max_fdset to have been increased above nfds.
>>
>>3)	RLIMIT_NOFILE has been lowered below the default
>>
>>	In this case, the system administrator or the user has gone out of 
>>their way to protect the system from inefficient (or malicious) 
>>applications wasting kernel memory.  The current code allows polling up 
>>to 1024 file descriptors even if RLIMIT_NOFILE is much lower, which is 
>>not what the user or administrator intended.  Well-written applications 
>>which only poll valid, unique file descriptors will never notice the 
>>difference, because they'll hit the limit on open() first.  If an 
>>application gets broken because of the patch in this case, then it was 
>>already poorly/maliciously designed, and allowing it to work in the past 
>>was a violation of POSIX and a DoS risk on low-resource systems.
> 
> 
> OK, thanks very much for the details. Now, call me an idiot, but why
> don't you consider broken the apps which are currently failing on
> newer kernels ? I'm starting to suspect that we have to sets of apps :

I do consider them poorly designed, but they're out there, and they used 
to work, and it doesn't violate POSIX to allow them to work again, so 
all things being equal, I'd like them to work on new kernels.

>   - those which rely on poll() failing for invalid fds (do they really
>     exist ?)

I hope not.  If so, they're already broken in most situations anyway.

>   - those which rely on poll() not failing for invalid fds.

This is what we've gotten reports of.  I suspect we haven't heard much 
about this because in most cases the offending apps get fixed to not 
poll invalid fds, but for some deployed proprietary apps that may not be 
an option.

> The poll(2) man page suggests what you're saying. Man pages from other
> OSes found on the net suggest various behaviours. I guess it's better
> to stick to what has been documented (ie: your fix) but with *infinite
> care*. Apps which need more than 1024 fds are not end-user mp3 players.
> Breaking them in a stable branch can have a huge impact. I'd like this
> patch to be tested in 2.6 long before 2.4, and also it would be good
> if we could find some feedback from affected people which could confirm
> that your patch really fixes their problems. If you have some customers
> reporting the problem in RHEL who confirm the fix, it would be nice if
> they accepted to inform us about the application(s) which need this fix. 

I agree.  The 2.6 patch is in -mm now.  The patch has been tested 
successfully with a synthetic reproducer under various vanilla and RHEL 
2.4 and 2.6 kernels, but we're still waiting on real-world customer 
results.  Let's wait and see how the customer tests and the -mm patch go.

-- Chris

-- 
VGER BF report: H 4.82384e-11