Subject: Re: [PATCH] uvm_map.c
To: J. Scott Kasten <firstname.lastname@example.org>
From: Jason Thorpe <email@example.com>
Date: 02/29/2000 16:37:23
On Tue, 29 Feb 2000 18:42:37 -0500
"J. Scott Kasten" <firstname.lastname@example.org> wrote:
> I researched the archives, and the port-m68k list in May of 1999 had discussion
> about exactly this type of issue from Chuck Cranor and Ken Nakata. Chuck
> found an issue with pointer wrap around in uvm_amap.c. His patch was applied
> back at release 1.9 of the file. I verified that his patch was still in the
> current release, however, I was still having the problem. This indicated to
> me that there must be other places where this can happen.
> I beleive that I found one such place in uvm_map.c release 188.8.131.52. After
> inserting a one line conditional for the wrap problem and recompiling the
> kernel, I am pleased to say that I have not seen the error in over 4 days
> now. I've kept the box compiling c++ code or otherwise abusing it for
> the entire 4 days, 24 hours a day. I was getting the problem every 4 to
> 8 hours before. Therefore, I beleive the problem is fixed and offer the
> enclosed diff to the port maintainers for consideration.
It appears that this code block is in the function uvm_map_submap(). This
function is used to create submaps of the kernel_map. I.e. the function
is called only during bootstrap, and the VA range is already checked.
I don't think this is the reason your system is losing the way it is.
-- Jason R. Thorpe <email@example.com>