Hi!
Just wanted to let you know that the warning introduced in
[PATCH] core remove PageReserved
triggers when using vbetool, which is needed on several systems for proper
suspend-to-mem support:
[4301282.746000] program vbetool is using MAP_PRIVATE, PROT_WRITE mmap of
VM_RESERVED memory, which is deprecated. Please report
this to [email protected]
Reports of this haven't generated many results yet, that's why I'm
addressing this with a subject line which startles more people ;)
http://lkml.org/lkml/2005/11/6/72
http://lkml.org/lkml/2005/11/6/76
http://lkml.org/lkml/2005/11/10/280
Dominik
Dominik Brodowski <[email protected]> wrote:
> Just wanted to let you know that the warning introduced in
> [PATCH] core remove PageReserved
It's not much of a warning, it seems to stop vbetool from working (which
may explain a few complaints about ACPI suspend being broken in 2.6.15 -
it's not, but vbetool is...)
vbetool (well, strictly it's LRMI, but...) needs to access real-mode
memory. On the other hand, it's probably a bad idea to let it actually
scribble over RAM that the kernel may be using. So
MAP_PRIVATE|PROT_WRITE seems to be the correct thing to do. This
certainly /seemed/ to work in older kernels, but doesn't any more. What
should I be doing instead?
(I'm also not quite sure why the error claims that it's deprecated,
whereas in fact it doesn't actually work at all. Breaking userspace
without warning isn't terribly nice)
--
Matthew Garrett | [email protected]
On Tue, 22 Nov 2005, Matthew Garrett wrote:
> Dominik Brodowski <[email protected]> wrote:
>
> > Just wanted to let you know that the warning introduced in
> > [PATCH] core remove PageReserved
>
> It's not much of a warning, it seems to stop vbetool from working (which
> may explain a few complaints about ACPI suspend being broken in 2.6.15 -
> it's not, but vbetool is...)
>
> vbetool (well, strictly it's LRMI, but...) needs to access real-mode
> memory. On the other hand, it's probably a bad idea to let it actually
> scribble over RAM that the kernel may be using. So
> MAP_PRIVATE|PROT_WRITE seems to be the correct thing to do. This
> certainly /seemed/ to work in older kernels, but doesn't any more. What
> should I be doing instead?
>
> (I'm also not quite sure why the error claims that it's deprecated,
> whereas in fact it doesn't actually work at all. Breaking userspace
> without warning isn't terribly nice)
Sorry about that, we really didn't expect that it was being used.
And sorry I didn't get the fixes ready in time for 2.6.15-rc2.
But they've gone into Linus' git tree a couple of hours ago.
Please let me know if tomorrow's 2.6.15-rc2-git3 does not work for you.
Hugh